Conference Programme Filter

Use the Select-Fields below to filter the programme.


PL - Plenary Lecture

Day: 14 February 2023
Time: 10:45 - 12:00 h

From Digitalisation to Autonomous Processes

Prof. Dr.-Ing. Hermann Nirschl, Karlsruhe Institute of Technology (KIT), Germany

In recent years, big efforts and investments have been made in the process industry to drive the digitalisation forward. This has led to extensive improvements in the design, the manufacturing and the operation of separation machines and systems. Huge progress has also been made in the field of simulation of the processes, so that now a prediction of the real performance in real time is possible. Therefore, it seems feasible in the near future to realize autonomous processes by means of a closed control loop, where the process models and the insitu measurement technology are coupled with a process control strategy. It is clear that just reduced order models, abstracted from complex simulations, are necessary to have a ‚faster as real time‘ performance which helps to predict the process in the future. Also insitu characterization devices will become more and more important for the realization of a ‚model predictive control‘ strategy. This not only allows an automatic optimization of the target variables, but also helps to ensure a high resource efficiency according to raw materials and energy consumption. The presentation explains the basics of autonomous processes and their implementation in separation devices like centrifuges.

Learn More at FILTECH 2023 Conference - Register Now!


K01 - Keynote Lecture I

Day: 14 February 2023
Time: 13:00 - 14:15 h
Room 1

Session Chair:
Prof. Sergiy Antonyuk

The composite filter media for removal of high-concern contaminants from water

Prof. Dr.-Ing. Andrzej Krasinski, Warsaw University of Technology, Poland

The presentation covers the enhancement of filtration performance by modification of porous media tailored for specific processes of water cleaning. The topic will include methods of filter structure modification by deposition or synthesis of particles on the fibers or granules to obtain a desired added functionality of filtration unit, including antibacterial, photocatalytic or/and adsorption capabilities. The presented applications refer to the cleaning of water from contaminants of recent concern, such as removal of heavy metals, pharmaceutical ingredients and prevention of microorganism colonization. This problem observed commonly in many applications can lead to a rapid clogging of the filter due to bacteria growth and reemission of these microorganisms due to their reentrainment from a biofilm to the outlet. Preventing the bacteria development can also be of a high importance in filters installed to eliminate microplastics, which are prone to bacteria deposition and the formation of biofilm. Other prospective applications like sorption of heavy metals and a novel system of integrated photocatalytic decomposition-sorption of organic pollutants will also be discussed.

Learn More at FILTECH 2023 Conference - Register Now!


G01 - Measurement Techniques

Day: 14 February 2023
Time: 13:00 - 14:15 h
Room 3

Session Chair:
Prof. Hans-Joachim Schmid

Real-world application of low-cost PM sensors in dedusting systems

F. Reinke*, J. Meyer, A. Dittler, Karlsruhe Institute of Technology (KIT), Germany

Low-cost PM sensors are widely applied in the field of particle immision measurement. In addition, they are already established in the application of emission characterization for the detection of temporal and local particle concentration. Due to those characteristics, low-cost PM sensors represent a promising approach for the use in autonomous process control and process management of dedusting systems.

For an effective process control and process management of dedusting systems, the characterization of particle properties (particle concentration and particle size distribution) is one of the key issues. Real-time access to relevant process parameters (particle concentrations and particle size distributions), e.g. by in-situ-measurements, is not feasible at the present development stage. The measurement of the particle properties should take place directly in the process (in-line). Therefore, in contrast to high-cost sensors, which cost above 20.000 EUR and are mainly suited for laboratory applications, particle measurement technologies available at reasonable costs are needed. For this reason, low-cost PM sensors for in-situ-measurement of particle concentrations and particle size distributions are to be investigated fundamentally with regard to their applicability in dedusting systems. The long-term stability of both the electronic and optical components of the sensors has not yet been investigated under the focus of emission characterization.

In this contribution, the aging behavior of low-cost PM sensors under idealized conditions (flow form, particle concentration levels, relative humidity), is presented in relation to the particle deposition inside the sensor...

Learn More at FILTECH 2023 Conference - Register Now!

Integration of pressure sensing system onto air filter

A. Khaldi, A.Bouhanguel*, H. Wu, L. Dupont, E. Daniel, F. Seguin, F. Theron, A. Joubert, Y. Andrès, C. Lahuec, IMT Atlantique; M. Duclos, Groupe Titanair, France

Air filter clogging causes an increase in energy consumption, albeit still lower than that required for heating or air conditioning, since the fans speed may be increased to keep a constant air flow. Nevertheless, taking into account the working time of fan in various buildings such as commercial center, hospital…, this overconsumption can be significant. To avoid this over-consumption, one can either replace the filters more frequently or monitor the filter pressure drop to avoid unnecessary maintenance. Ultra-low energy monitoring system will thus help significantly reduce the fans power consumption [1,2] and improve the maintenance of central air handling units.

The aim of this work is to develop a filter clogging monitoring system by measuring the difference between upstream and downstream pressures of the filter. The energy supply and communication system of the connected filter will be wireless for ease of maintenance...

Learn More at FILTECH 2023 Conference - Register Now!

Preselection of fibres by igc techniques for applications in gas filtration

R. Heidenreich*, L. Kotte, D. Keßlau, Institute of Air Handling and Refrigeration (ILK), Germany

Replacing fossil fuels for heat and power generation by biomass combustion processes is a main topic and challenge during the coming years. By increasing the number of biomass heating systems without additional gas cleaning high dust load of the ambient air will be created. Straw, a role jutting out befit the energetic use of biomass, is included at this. For a utilization of this considerable potential however technical measures are necessary.

In case of this German government has given a new law for emissions. Stage 2 of this policy is valid until 2015 and restricts the emission value for dust down to 20 mg/m³. Important for the function of furnace is a low resistance of filtration system. Aerosols from wood and biomass- firing have a special behaviour. If the surface energy of filtration material is correlating to the loading of dust the separation efficiency increasing from 20 to 90 %. In addition, agglomeration effects are important for separation effect along the fibre structure.

Nonwoven fabric made by a composition between a coarse layer and a fine layer are able to separate the ultrafine dust from the gas stream. The key issue is the connection with water- jet between the fine and the coarse layer. But also the fibre material is important for the separation effect.

The high filtration efficiency for the biomass fly ash can’t be declared only because of mechanical effects. Surface effects and electrical potential have to be included. It was found that...

Learn More at FILTECH 2023 Conference - Register Now!


L01 - Depth Filtration and Adsorption I

Day: 14 February 2023
Time: 13:00 - 14:15 h
Room 2

Session Chair:
Prof. Urs A. Peuker

Pre-coat filter as advanced treatment step for further removal of dissolved and particulate emerging pollutants from municipal wastewater

H. Geers*, Hoffmann Maschinen- und Apparatebau GmbH; K. Bauerfeld, S. Karwat, Technical University Braunschweig, Germany

Pharmaceuticals, detergents, residues of care products, biocides, anti-corrosion agents and other substances of everyday use are anthropogenic trace substances found in municipal wastewater. State of the art municipal wastewater treatment plants (WWTPs) designed for nutrient removal are unable to reduce most of these emerging pollutants sufficiently. Therefore, many wastewater treatment plants face challenges to further improve effluent quality by additional advanced treatment technologies. Various treatment steps are suitable, though powder activated carbon (PAC) is often used as a broad band adsorptive to reduce dissolved trace substances.

In addition, the fate of microplastic particles (< 5 mm) during wastewater treatment processes has come into focus and has been thoroughly studied during the last years. Although these research-oriented investigations proved high elimination rates for particles >10 µm during conventional wastewater treatment processes, the fate of smaller particles is nearly unknown. However, especially very small plastic particles with their corresponding huge surface can adsorb anthropogenic trace substances and lead to locally enhanced concentrations of various contaminants. Therefore, in order to address both challenges, the removal of dissolved trace pollutants and very small particles, has to be combined to reduce the contamination of the receiving waterbody.

Precoat filters are used since decades as a well-known, compact technology to filter suspensions with low particle concentrations in various fields of process engineering. Depending on the pre-coat material used, smallest particles (down to the nm range) can be removed. Municipal wastewater treatment, however, provides a new opportunity of application.

The new innovative concept of ongoing studies now is to combine the good particle retention abilities of a pre-coat filter with the broad band adsorption capabilities of PAC. The PAC is mixed with cellulose to form the pre-coat. Within the pre-coat layer the intense contact of wastewater and PAC reduces the contact time needed for the adsorption to a few seconds. Variations of the PAC and cellulose particle size distributions allow specific adjustments of this pre-coat to optimize filtration performance.

The modification of the pre-coat filter technology is currently tested as a suitable post-treatment option at municipal wastewater treatment plants. Initial results show promising performances regarding both adsorption and filtration, once operating boundary conditions are adjusted. Based on a first economic evaluation, the specific treatment costs are estimated to be in the range of established technologies for trace pollutants removal regarding comparable treatment objectives....

Learn More at FILTECH 2023 Conference - Register Now!

Prevention of microbial contamination and biofouling in water filtration with AGXX®

M.-L. Harwardt*, R. Ahlers, A.-L. Meza-Chincha, M. Danz, Heraeus Precious Metals - Antimicrobial Technologies; C. Meyer, Largentec GmbH, Germany


Microorganisms encounter us ubiquitously in daily life. While the presence of some microorganisms is not harmful to humans or even favorable in contexts of biological metabolic processes, some strains of bacteria, viruses, or fungi pose a serious threat to human health. Especially, in aqueous media pathogens may multiply easily. Ensuring high quality water supply is one of the basic needs of civilized society. Water filtration devices are deployed in fields as diverse as wastewater treatment, household filters, or in swimming pool water recycling. However, filters are prone to contamination by microorganisms and biofouling endangering not only consumer health but also shortening product lifetimes. Particularly in the light of the spread of multi-resistant germs, it is more crucial than ever to protect filters from bacterial growth and to enhance water quality by innovative antimicrobial technologies.

AGXX is a new antimicrobial technology which is based on reactive oxygen species (ROS) produced from water and oxygen by a catalytical reaction supported by two precious metals. Additionally, a microelectric field between the two precious metals increases the antimicrobial effect. AGXX is not based on the release of any metals or harmful compounds into the environment and therefore offers long-lasting protection. To this date, it has shown antimicrobial efficacy against over 130 microorganisms including bacteria, viruses, algae, and fungi, among others silver-resistant E. coli strains, methicilin-resistant S.aureus (MRSA), or CoV2 viruses. AGXX application was also successful in prevention of biofilm formation. The technology is available in various product forms optimized for diverse applications. The technology initially used inorganic carrier powders, such as activated coal, aluminum oxide or other carrier materials, well suited for incorporation in textile filters. Recently, the AGXX technology was also successfully applied to various types of activated carbon granules and pellets which are easily applicable in activated carbon-based water filters. AGXX carbon granules showed excellent antimicrobial efficacy in ASTM and laboratory water filtration tests. Currently, samples thereof are tested in wastewater treatment and purification systems for swimming pools at the Fraunhofer UMSICHT institute and the IWW. The aim of these projects is to protect human and animal health by preventing the spread of pathogens by addition of AGXX....

Learn More at FILTECH 2023 Conference - Register Now!

The evolution of Disruptor® charged fiber technology

E. Nelson*, F. Cousart, D. Russell, Ahlstrom, USA; C. Läck, Ahlstrom, Sweden; J. Kaukopaasi, Ahlstrom, Finland, C. Theron, Ahlstrom, France

Disruptor® technology was first introduced to the industry over a decade ago. The technology was a significant innovation, but there was room for improvement. It removed virus, bacteria, and cysts, but virus removal was only on the order of 2 log. The media required special considerations to pleat and make into filters. By definition, the grade contained large amounts of charged material and unfibrillated fibers, leaving very little room to add fibrillated fibers for strength. The technology was impressive, but defined and limited. It appeared there would only ever be one product.

The technology has evolved considerably. The internal strength of the product was increased by use of specialized fibers and binders. Overall strength was improved through lamination. Virus was identified as one of the most accurate measures of performance. Virus removal was improved from 2 log to greater than 4 log.

Along with improvements in basic performance came improvements in test methods. The increased removal of virus allowed use of larger plated volumes, which in turn increased the accuracy of the initial virus removal test. Virus and bacteria capacity curves were also established and surrogates for virus and bacterial made initial screening possible. Erythrosine, fluorescein, humic acid, tannic acid, and ATP have all been used to measure performance. Some of these tests are colorimetric tests which eliminate the need for biological plating. Removal of other organics, such as TEP and endotoxins were demonstrated. Removal of specific pathogens, like legionella, was verified. A method of passing P231 with multi-layer products was demonstrated. Studies expanded from removal of organics to inorganics like iron and lead.

Given the improvements in performance and strength, it became possible to incorporate functional additives into Disruptor® products. The first innovations included removal of chlorine and rapidly expanded to include tailored solutions for specific markets. More recently, promising work has been conducted with removal of lead.

Gravity flow is a key segment of today’s water market. The improvements in removal efficiency have allowed the pore size of the base sheet to be increased. Improved lamination techniques have also increased flow. Today’s gravity flow products have twice the flow of traditional products designed for pressure applications.

Innovation continues. Current partnerships will soon result in the launch of higher performing products with more specialized capabilities...

Learn More at FILTECH 2023 Conference - Register Now!


K02 - Keynote Lecture II

Day: 14 February 2023
Time: 14:45 - 16:00 h
Room 1

Session Chair:
Martin Lehmann

Electrostatically charged PVDF nanofiber filter for filtering submicron- and nano-aerosols

Prof. Wallace W.F. Leung*, et. al., The Hong Kong Polytechnic University, Hong Kong SAR

Existing filter media are not very effective in capturing submicron aerosols (<1 micron) and nanoaerosols (≥ 100 nm). These aerosols can be pollutants in air or aerosols bearing deadly viruses, such as SARS-CoV-2 virus that triggers the worldwide pandemic since March 2020. Existing filter media with microfibers are poor in mechanical capture on these tiny aerosols. For charged microfiber filters, the filter efficiency has been improved, yet they suffer from skin effect for which a cake forms rapidly on the filter surface during aerosol loading for which most of the filter proper downstream is not being used. When the filter interior is equipped with disinfectant agents attached to the fibers, these become redundant as the incoming aerosols are deposited in the cake on the filter surface and not inside the filter. There is a need to prolong depth filtration for disinfection and to load the filter uniformly with aerosols.

A patented multilayer charged polyvinyl difluoride (PVDF) nanofiber filter has been developed that address higher efficiency, lower pressure drop, and higher dust holding capacity for which the entire filter can be fully utilized during aerosol loading and disinfection can be done inside the filter.

The filter has been tested against NaCl aerosols in the laboratory and difficult-to-filter amorphous, ambient aerosols indoors/outdoors simulating aerosols bearing SARS-CoV-2 viruses. The PVDF multilayer charged nanofiber filter media have superior filtration efficiency of...

Learn More at FILTECH 2023 Conference - Register Now!


G02 - Filter Test Systems

Day: 14 February 2023
Time: 14:45 - 16:00 h
Room 3

Session Chair:
Prof. Achim Dittler

Test of efficiency by particle size and total efficiency – Influences of test parameters and measuring technology

M. Schmidt*, PALAS GmbH, Germany

The difference in efficiency results in filter and filter media testing is often based on the difference in measuring technology. Scattered light particle sizers or SMPS systems usually used in fractional efficiency testing vs. the integral efficiency obtained by a scattered light photometer.

Various standards define different test instrumentation to measure the efficiency of various filters and filter materials for different applications.

Commonly used is either the efficiency by particle size as ISO 11155-1 and DIN EN 71460 -1+3 in Cabin air filtration, ISO 29463 in HEPA/ULPA filtration, ISO 16890 in general ventilation filtration testing, or the integral efficiency with a defined test aerosol as by EN 149, EN 143, 42 CFR 84, and GB 2626 in mask testing, DIN EN/IEC 60335-2-69 A.3/AA.22.201.2 or DIN IEC 60312 in vacuum cleaner filter testing.

In the PMFT Series by Palas® the aerosol spectrometer Promo® was successfully integrated to measure integral efficiency with comparable results to the photometer as described in the mask testing standards. Based on the measurement of efficiency by particle size, the system can adjust the particle size distribution to the requirements of the different standards. This is necessary to get comparable results with the photometer method.

Additional advantage by using the particle counting device is for sure to obtain efficiency by particle size also. The system can be adjusted to different test conditions concerning particle concentration and air flow of filter media testing according to the standards for cabin air filters, general ventilation filters and to some extend even HEPA filters.

This presentation outlines the technical background to convert the data from the Promo® Aerosol spectrometer in comparable results with photometer-based measurements. The results from round robin tests for face masks in Europe and United States prove...

Learn More at FILTECH 2023 Conference - Register Now!

Investigation of viral aerosols on surfaces and in air for a better understanding of applying bacteriophages phi6 and MS2 as viral surrogates for air filter evaluation

B. Führer*, C. Hartl, A. Wlodarczyk, J. Pokorny, V. Sharp, C. Kirchnawy, OFI Technology & Innovation Ltd, Austria

Due to the still ongoing Coronavirus (COVID-19) pandemic the process of virus transmission and infection prevention are the subject of several research studies. It is well known, that infectious particles such as viruses or bacteria can be transmitted via surfaces or directly via air from human to human. This mechanism depends on the virus species and the surface material but also on environmental conditions such as temperature or relative humidity (Whitworth et al, 2020). The behaviour and stability of viral particles on surfaces and in air can play a significant role when implementing viruses into air filtration processes (Verreault et al, 2015).

As air filters, air cleaning devices or protection masks are usually tested under laboratory conditions using predominantly non-biological aerosols such as DEHS, salt particles or tobacco smoke, it is important to also generate knowledge about the behaviour of viruses. Therefore, as a first step two surrogate viruses were chosen for further investigation of their stability on four different surfaces at three temperatures over a defined period of time (three months). MS2 bacteriophage, a well-known bacterial virus, was chosen as representative for a robust non-enveloped virus, whereas phi6 bacteriophage was selected as an enveloped virus posing as a surrogate for Ebola virus or Coronavirus. In a second step, both viral surrogates were meant to be used as aerosol for testing air filters within a filter test rig. While establishing this process, factors such as sampling stress by the aerosol generator or stable distribution within the air stream were considered. The aim was to compare the two viruses within the different setups in order to establish a stable test aerosol containing MS2 or phi6 bacteriophages...

Learn More at FILTECH 2023 Conference - Register Now!

Performance evaluation of engine air filter media coated with nylon nanofibers

J. Johnson*, M. Muzwar, R. Chetty, K. Arul Prakash, Indian Institute of Technology Madras, India

The performance and operation of vehicles mainly depend on clean air supply to the IC engines. Air filters are necessary for providing clean air to the engines. A good air filter supports the engine operation by ensuring that the air entering the system is clean and free of grit and dust. Fibre diameter and pore size are critical parameters that significantly affect the air filter media’s filtration performance and dust deposition. Nanofibers are typically fibres with less than 1 μm, and the nanofiber-coated filter media offers higher filtration performance than the conventional filters. The addition of nanofibers also extends the life of the filter by making it easier to clean because the fibres keep the particulate at the surface rather than depth loading. In this study, Nylon nanofibers were coated over a cellulose based conventional filter media using an electrospinning process. The coated media’s performance was evaluated in terms of filtration efficiency, quality factor (Q-factor), etc. The filtration test was performed on a lab-scale air filtration test apparatus and compared to the conventional filter media. The addition of Nylon nanofibers on the surface of the conventional media showed...

Learn More at FILTECH 2023 Conference - Register Now!


L02 - Depth Filtration and Adsorption II

Day: 14 February 2023
Time: 14:45 - 16:00 h
Room 2

Session Chair:
Prof. Andrzej Krasinski

Surface modification of polypropylene non-woven filter by O2 plasma/acrylic acid enhancing Prussian blue immobilization for aqueous cesium adsorption

N. Dehbashi Nia*, S.-W. Lee, T.-H. Kim, Y. Hwang, Seoul National University of Science and Technology; S. Bae, Konkuk University, South Korea

Studies have shown that Prussian Blue (PB) is an effective adsorbent for radioactive cesium, and immobilize it on the filter could create a superior adsorption material for aqueous cesium released from the nuclear power plant accident. This study aims to confirm that immobilizing PB on the polypropylene (PP) non-woven filter can provide high cesium adsorption performance. The PP filter surface was required to be modified by O2 plasma irradiation and acrylic acid modification because PP has an inert surface property. The change of filter characteristics was demonstrated via multiple tests: contact angle, tensile strength, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), while PB content was tested by inductively coupled plasma optical emission spectroscopy (ICP-OES), thermogravimetric analysis (TGA-DTA), and pore size analysis. It was confirmed that the surface modification steps successfully did the surface functionalization, and subsequently, PB immobilization was improved by the surface functionalization. The kinetic experiment showed...

Learn More at FILTECH 2023 Conference - Register Now!

Removal of superfine adsorbents with 3D woven high performance OptiFiber pile cloth media

T. Fundneider*, R. Schäfer, U. Grabbe, Mecana Umwelttechnik GmbH; Switzerland; F. Kirchen, S. Lackner, Technical University Darmstadt, Germany

The removal of powdered activated carbon (PAC) as an adsorbent for organic micropollutants from wastewater with Pile Cloth Media Filters (PCMF) is state of the art. As synergy effects in this process, low total phosphorus (TP < 200 µg/L) and total suspended solids (TSS < 2 – 3 mg/L) concentrations as well as microplastic removal were identified. With 3D woven Pile Cloth Media (PCM), the residual PAC concentration (TOC gradient method) in the PCMF effluent is lower than the limit of quantification (0.2 mg/L). To further minimize the space requirements as well as construction and operating costs, superfine PAC (sPAC) with d50 ≤ 1 – 5 µm is necessary. Currently, membranes are used for the retention of sPAC in water and wastewater treatment plants (WWTP). Novel designed and modified PCM enables the sPAC removal. This research focused on the effect of sPAC and additives on the long-term performance and solids removal efficiency of PCM, design and operation parameters of PCMF as well as the efficiency of sPAC in comparison to PAC...

Learn More at FILTECH 2023 Conference - Register Now!

Deep learning enhanced algorithm for in-line characterization of particle size and shape in depth filtration processes

S. Daus*, U. A. Peuker, Technical University Bergakademie Freiberg, Germany

The design and operation of depth filters are still demanding tasks today and require detailed knowledge of the system. Changes in the state of the system - induced by fluctuating process conditions or particle agglomeration - can affect filtration performance. Therefore, obtaining information on the size and shape of suspended solids is crucial for filter design and subsequent monitoring of the filtration process. To a large extend, particle size measurements are performed using established off-line methods such as laser diffraction. These procedures require sampling and handling of the samples and are not suitable for process monitoring due to dead times. On-line methods, on the other hand, use process disruptions such as bypass loops that can alter particle characteristics.

A suitable tool to overcome the clear disadvantages of off- and on-line measurements is the use of in-line imaging probes. They can provide improved insight into the process by capturing 2D projections of the particles directly within the process and at any instance. However, processing images acquired with probes is difficult due to challenges such as unsteady illumination conditions and the presence of out-of-focus objects. To obtain quantitative information a reliable algorithm is needed. This is where machine learning can help. In recent years, machine learning algorithms, especially deep learning methods, have outperformed traditional image analysis techniques in many fields such as biomedical imaging or bubble detection in two-phase flow. The application is currently still limited in many cases by the fact that a sufficient amount of meaningful, labeled data has to be available. Once this condition is met, the combination of in-line probes and deep learning algorithms can simplify the optimization of depth filtration processes through accurate, easy-to-use metrics.

In the present work, an inline probe was used to study the filtration of a suspension with ceramic depth filters in a pilot plant. A convolutional neural network (CNN) was trained to identify particles and microbubbles that are present in the system...

Learn More at FILTECH 2023 Conference - Register Now!


G03 - Air Filtration

Day: 14 February 2023
Time: 16:45 - 18:00 h
Room 3

Session Chair:
Prof. Gerhard Kasper

Influence of material compression on the mechanical and electrostatic capturing efficiency of filter media

C. Mercier*, R. Kirsch, S. Osterroth, S. Rief, Fraunhofer Institute for Industrial Mathematics (ITWM); S. Antonyuk, M. Kerner, University of Kaiserslautern-Landau, Germany

One of the main design goals for filter media is a high separation performance while pressure drop is low. During manufacturing processes such as pleating filter media or during operation, the nonwoven material is compacted locally which is of importance for the mentioned quality characteristics, because the compaction leads to a local variation of the fiber volume fraction and therefore, to a non-uniform distribution of flow resistance and filtration performance.

In this work, the influence of compression on the performance of flat filter media is examined both for “classical” materials using mechanical deposition and electret media. Two different fibrous media made of polypropylene (PP, see Figure 1) investigated whereby one is electrically charged. After the characterization of both media by the thickness, basis weight and airflow for a given pressure drop, properties like the solid volume fraction and flow resistivity can be deduced...

Learn More at FILTECH 2023 Conference - Register Now!

How to quantify the influence of solid volume fraction heterogeneities on fibrous filter efficiency and permeability by computational simulations

N. Bardin-Monnier*, A.S. Rathore, A. Charvet, Lorraine University, France

Air pollution, due to high concentrations of fine/ultrafine particles, was ranked as the leading cause of death in the world, in a recent report by the State of Global Air (2008). The efficient fiber filtration process, for this fine particle separation, encounters great difficulties of clogging due to a significant increase in pressure drop resulting from the higher specific surface area of particles. To delay the onset of clogging, the surface area of fiber filters is increased through the pleating process. However, this method of manufacturing may generate local Solid Volume Fraction (SVF) heterogeneities. This filter characteristic being the critical parameter affecting the filter performance, it is essential to know the impacts of such modifications on the permeability and the efficiency of a filter.
To study the impact of solid volume fraction heterogeneties on the performance of filters, the filter structure needs to be perfectly characterized but available experimental techniques only allow access to very macroscopic information. Hence, for this purpose, the CFD approach was adopted in the present study to perform a detailed numerical study using the software, GeoDict...

Learn More at FILTECH 2023 Conference - Register Now!

How Eurovent is improving ventilation and industry decision-making

T. Stoffel*, DELBAG GmbH, Germany

Choosing the right air filtration system can be a difficult decision, and even with manufacturer information to hand, it can be hard to assess long-term efficiency in tricky filtration applications. Of course, this also assumes that there are no discrepancies between the documentation and product you receive.

EUROVENT is an umbrella association which sets out to ensure that indoor climate (HVAC), process cooling, food cold chain, and industrial ventilation industries provide complete transparency and security to customers, but what does a EUROVENT certification mean?

One of the numerous misconceptions of EUROVENT is, that EUROVENT in many ways resembles an industrial trust that ensures market dominance of a selected number of companies in the ventilation industry. This notion includes the operates via multilateral distribution agreements, for instance. Instead, EUROVENT an umbrella organisation of European industrial associations and its dominating entrepreneurial principles is the full respect of European anti-trust laws.

EUROVENT is headed by a Commission whose members are delegates from 17 participating European industrial associations. The EUROVENT Commission sets strategic objectives for the entire EUROVENT organization and to emphasize its democratic foundations all 17 members of the EUROVENT Commission have equal voting rights, regardless of their own number of members or the gross financial turnover of their national members.

Product groups are installed by the EUROVENT Commission to focus on different subsectors of the ventilation industry and aim to provide technical recommendations to legislative supranational bodies....

Learn More at FILTECH 2023 Conference - Register Now!


G04 - Particle-Collector-Interaction

Day: 14 February 2023
Time: 16:45 - 18:00 h
Room 4

Session Chair:
Prof. Arunangshu Mukhopadhyay

Concept of magnetic-induced gas cleaning filter regeneration – Fundamental investigation of particle structure detachment from a magnetizable single fiber

J Szabadi, J. Meyer*, A. Dittler, Karlsruhe Institute of Technology (KIT), Germany

processes of particle structures. Either the collectors, the particles or both can be magnetized. Magnetic separation between particle structures and collectors is already well established in the field of solid-liquid separation and also allows separation of particles in the lower submicron size range on an industrial scale (Ladislav 2001; Svarovsky 2000).

The use of magnetic effects, such as magnetic-induced motion excitation for the regeneration of individual filter fibers (in the field of depth filtration) or entire filter media (in the field of surface filtration), could also find application in the field of gas-particle separation technology. However, there are no studies in literature dealing with the separation of non-magnetizable particle structures from ferromagnetic fibers by exploiting magnetic effects. The detachment of non-magnetizable particle structures depends on the structural build-up of the particle layer to be detached and the loading of the fiber (Löffler 1972; Müller 2017). Therefore, knowledge of the morphology of the particle layer and the total load is of high significance. It is expected that the different morphology of particle structures will also result in differences in the detachment behavior.

For the fundamental investigation of the novel regeneration concept by magnetic forces, the detachment of non-magnetic particle agglomerates will be performed using a single ferromagnetic fiber (Figure 1). The fiber is fixed on one side and is magnetized and deflected by the application of an external magnetic field (Helmholtz coils). If the inertial forces acting on the particle agglomerates due to the acceleration of the fiber are greater than the adhesive forces, the agglomerates detach from the fiber.

The presented work aims to introduce the novel concept of magnetic-induced cleaning and to present first findings on magnetic-induced particle detachment...

Learn More at FILTECH 2023 Conference - Register Now!

Improved computer modeling of charges in electret filter media

L. Cheng*, J. Becker, A. Wiegmann, Math2Market GmbH, Germany; K. Lee, FITI Testing & Research Institute; J. Kim, Seoul National University, South Korea

Electrical charges in fibrous filter media can lead to non-monotonic penetration curves because the dominant effect of filtration changes over time. The two orange curves in Figure 1 show how the penetration is low at the beginning of the experiment, then increases and finally decreases again. At first, the charges are so high that most particles get trapped. Over time, as more mass deposits, the charges weaken, and fewer particles are trapped. Later still, as enough mass was deposited, captured particles contribute increasingly to the capture efficiency and more particles are trapped again.

Our earlier attempts to simulate this behavior could not reproduce this behavior, as illustrated by the simulation results on the left of Figure 1. They were not taking decreasing charges into account. By making the electrical charges depend on the deposited dust, the digital filtration experiments reproduce the general behavior of the physical experiments as illustrated on the right of Figure 1.

As there are many unknowns regarding how exactly the charge reduction depends on the deposited mass, we developed and present a general modeling framework that allows the detailed modelling of electrical charges, both depending on the deposited mass but also on properties of individual fibers, in order to improve the agreement of digital filter experiments with physical filter experiments...

Learn More at FILTECH 2023 Conference - Register Now!

Validation of the simulation of continuous aerosol deposition at various wire mesh types including non-trivial particle-particle and particle-wire adhesion forces by laboratory measurements

K. Schmidt*, S. Ripperger, IT for Engineering (it4e) GmbH; A. Mantler, F. Meyer, Haver & Boecker OHG, Germany

Simulation of fluid flow and particle deposition with 3D computer models of the pore structure of filter media is a tool for rapid cost-efficient layout of filter media for industrial filter applications, and moreover for improvement of the scientific understanding of filter processes and the involved material systems.

To obtain reliable simulation results which reproduce the real behavior precisely, the simulation must be validated under well-defined laboratory conditions. The validation usually consists of the comparison of pressure drops, filtration efficiencies, deposited particle masses and/or filter cake heights. If the comparison of simulation and measurement results shows considerable deviations, the physical models and numerical implementation of the simulation must be revised, and also measurement errors must be considered.
The aim of this work is to validate the simulation of continuous aerosol deposition at wire meshes, where non-trivial adhesion forces occur between particles and particles and between particles and wires, with it4e’s simulation software DNSlab®...

Learn More at FILTECH 2023 Conference - Register Now!


L03 - Advanced Pore Structure Analysis

Day: 14 February 2023
Time: 16:45 - 18:00 h
Room 1

Session Chair:
Dr. Harald Anlauf

Description of depth filtration in filter aid structures through 3D microscopy

T. Buchwald*, J. Friebel, D. Neuber, U.A. Peuker, Technical University Bergakademie Freiberg, Germany

Filter aids are used whenever the solids to be separated from a suspension are too fine to be held back by the filter medium. The increased surface area of filter aids such as kieselguhr lead to a higher retention rate compared with any other filtration principle. However, the use of filter aids means an additional operational cost and the amount of solids used should be kept to a minimum. It is therefore paramount to evaluate at which point a filter aid structure will reach the point of breakthrough, i.e. when the actual contamination will have passed through the filter aid.

The phenomenon of breakthrough of contaminant is the direct result of depth filtration of the smaller particles inside the filter cake, which is made predominantly of filter aid particles. The process of depth filtration can be described by several theoretical models, which, however, have yet to be confirmed by a proper experimental investigation.

To understand the processes of depth filtration better, a method was devised to determine the amount of impurities in the depth of a filter cake by means of 3D-computed tomography...

Learn More at FILTECH 2023 Conference - Register Now!

Investigation of the influence of pore morphology on the deliquoring behavior of filter cakes using X-ray tomography

E. Löwer*, U.A. Peuker, Technical University Bergakademie Freiberg, Germany

The morphology of particles is one of their most important characteristics and has a significant influence on their bulk properties. These include flow properties, tensile strength, wall friction coefficient, but also rheological behavior. The manufacturing or further processing of the particles determines the particle morphology. Particles that have passed through different comminution stages or different drying technologies show different shapes, which in turn affect the aforementioned properties. Consequently, knowledge of morphology is crucial when apparently similar particle systems undergo the same macro process, but their different process behavior results in varying outcomes.

During the separation of solid particles and a liquid by cake filtration, the morphological properties also have a decisive influence on the separation process. They determine both the suspension properties and the structure of the resulting filter cake. Depending on the character of the morphological properties of the particle system, the pore space can also vary in its properties. This variation determines not only the flow behavior of the mother liquid but also of the subsequent flowing gas or washing liquid if dewatering or washing of the porous structure is desired. In the case of the first, or washing using immiscible fluids, the morphology of the particle skeleton and thus of the inverse void structure can also influence the formation of the three-phase interface, which is partly responsible for the presence of hydraulically isolated liquid regions. These liquid clusters represent the largest fraction of the remanent saturation before adhesion, pore, and adsorbed liquid in the bulk.

Commonly, particle morphology is usually determined through various microscopic methods. Therefore, filter cakes of various particle morphologies were...

Learn More at FILTECH 2023 Conference - Register Now!

Characterisation of nonwoven materials with the POROLUXTM100

M. Ängeslevä*, D. Dutczak, E. Pattyn, K., I. Struzynska-Piron, D. Pattyn, Aptco Technologies, Belgium; Chojnacka-Górka, K. van der Kamp IB-FT GmbH, Germany

The primary purpose of a filter medium used in filtration processes is to ensure the retention of the components from a solution or a suspension. A porous structure of a filter medium works as a barrier allowing free passage of one or more components while retaining another. In addition, the resistance to air or fluid flow depends on the size of individual pores and the number of these pores per unit area. Therefore, the determination of the pore size and pore size distribution in the filter media is vital for filtration. Nonwovens are one of the fast-growing segments of filter media production since they provide fine filtration for both liquids and gases. The measurement of the pore size and pore size distribution in nonwoven filter media can be challenging since the porous structure in such materials is pretty open. Thus, very low pressure should be applied to displace the wetting liquid from such large pores. Moreover, as the gas flow through the nonwoven sample is relatively high during the measurements, the evaporation of a wetting liquid can easily occur. Therefore, the pore size measurement should be fast enough to avoid such circumstances.

To overcome the challenges typical for the measurement of nonwoven materials in the capillary flow porometry, a POROLUXTM100 was developed. This is a gas-liquid porometer based on the pressure scan method. In the pressure scan system, gas pressure continually increases while the resulting flow rates are recorded simultaneously. In such a system, one can get immediate and continuous measurements of both pressure and gas flow. This is a fast and reproducible method and is, therefore, ideal for measuring nonwovens.

The main aim of this work was to test and demonstrate the applicability of the POROLUXTM100 pressure scan system for the measurement of the pore size and pore size distribution for nonwoven filter media. Particular attention was paid to...

Learn More at FILTECH 2023 Conference - Register Now!


L04 - Particle Washing

Day: 14 February 2023
Time: 16:45 - 18:00 h
Room 2

Session Chair:
Prof. Bernhard Hoffner

Filtration and washing properties of black mass residues from battery recycling

U.A. Peuker*, T. Lyon, E. Löwer, Technical University Bergakademie Freiberg, Germany

In the last two decades, lithium-ion batteries have changed our personal life, since more and more tools and transport vehicles have become electrified using these batteries as energy storage devices. The shelf life of a battery depends on the application case and amounts from 6 to more than 15 years. The regulation requires the recycling of the batteries at their end of life and in the last decade, several recycling processes have been subject to research, development, and partly implementation as well. All these processes undergo somewhere in their process chain a suspending step, where the active material, the electrode coating, which is called black mass is mixed with water. Here arises the question concerning the solid-liquid separation properties of this system. The black mass itself is a mixture of the delaminated coating of both the anode and the cathode material, which have a typical primary particle size of < 20 µm (cathode) and < 30 µm anode, but in recycling these primary particles are agglomerated to a certain extent using a polymeric binder. These agglomerates also contain a salt load (conducting salt, e.g. LiPF6) as well as intercalated Li-ions from the functionality of the battery itself.

The case study presented here aims at quantifying the washing behavior of the black mass fraction regarding the recovery of Lithium as well as Phosphorus. The filtration experiments show...

Learn More at FILTECH 2023 Conference - Register Now!

Wash liquid application: A blind spot of cake washing

H. Henn*, F. Sauer, B. Hoffner, Mannheim University of Applied Sciences, Germany

The addition of wash liquid to the cake surface is a blind spot in the design of cake washing processes. The design of industrial processes is usually carried out using well-defined laboratory tests, which are mainly focused on the determination of wash curves and cake-specific parameters. The interaction of the wash liquid with the filter cake surface is usually assumed to be negligible. However, in industrial processes effects occur such as partial reslurrying of the filter cake, which leads to a preliminary contamination of wash liquid with impurities contained in the pore liquid. As a result, the outcome of the washing process deteriorates unpredictably. Although the negative influence of partial cake reslurrying and wash liquid contamination is qualitatively known in practice and actions are taken to avoid it, there is no method to describe the extent and the resulting influence of the pre-contamination of wash liquid on the washing result. In previous publications, imperfections due to the wash liquid application are described only qualitatively. Therefore, a method is needed to quantitatively evaluate the interactions of the wash liquid with the cake surface regarding imperfect cake washing.

This paper deals with the quantification of imperfections during wash liquid application with the focus on partial cake reslurrying...

Learn More at FILTECH 2023 Conference - Register Now!

Displacement washing of inhomogeneous filter cakes

F. Sauer*, H. Henn, B. Hoffner, Mannheim University of Applied Sciences, Germany

Displacement washing is a well-known process for the separation of dissolved impurities or valuable substances from filter cakes. In general, process design assumes ideal process conditions (e.g., constant cake height, homogeneous cake structure, ideal distribution of wash liquid, etc.) and is based on lab-scale experiments. However, this assumption usually is only partially valid in small-scale equipment and not valid at all on larger scales. Many design-related inhomogeneities can occur by default on industrial-scale filtration equipment. E.g., differences between the immersion time of the leading and trailing edge of the individual cells in the slurry on drum and disk filters lead to inhomogeneous filter cake height. Additionally, unsteady and non-uniform slurry feed conditions as well as maldistribution of wash liquid may further enhance filter cake inhomogeneities.

A two-dimensional model for the displacement washing of inhomogeneous, isotropic filter cakes based on the dispersion model is proposed (method development). Experimental data of preliminary experimental studies is used for the validation of the model. Simulated concentration profiles and color experiments agree well. Comparison of experimental and simulated wash curves shows that...

Learn More at FILTECH 2023 Conference - Register Now!


G05 - Industrial Air and Gas Cleaning

Day: 15 February 2023
Time: 09:00 - 10:15 h
Room 3

Session Chair:
Dr. Matthias Waldenmaier

Innovation meets filtration - Efficient filtration up to 160 °C

K. Schmitt*, Herding GmbH Filtertechnik, Germany

Filtration solutions and dedusting systems make a significant contribution to safe production in the company. In this context, it is important to be able to meet the individual requirements of the process and the associated filtration technology. Innovation and development are the driving force in today's globally networked world. Especially in processes with high temperatures it is important to concentrate on the core tasks, namely the permanent further development of the process as well as the focus on pure productivity. Therefore, a filtration system needs to set new standards....Examples include various applications like dryers, biomass combustion plants, rotary kilns, glass tank dedusting and high-temperature filtration downstream of mill systems and so on....

Learn More at FILTECH 2023 Conference - Register Now!

SMF®- Industrial filtration processes with potential for CO2 reduction

S. Steigert, K. Schrewe*, HJS Emission Technology GmbH & Co. KG, Germany

SMF® modules are proven for a very large number of exhaust gas filtration applications used by vehicle manufacturers for applications that are subject to the current European emission legislation and thus strict requirements for particle number reduction. More than 2 million m² of HJS Sintered Metal Filter (SMF®) material have been produced for these applications within the last 15 years, with a peak production of 300.000 m² p.a..

In order to qualify the SMF material for industrial filtration processes and to describe the performance of the current filter medium measurements according to the corresponding standards of both oil filtration, e.g. Mulitpass acc. ISO 16889 and testing regulations for air filters as ISO 5011, VDI 3926 and ISO 16890 have been carried out. There are first applications in the industrial filtration of gases, in which in addition to the thermal robustness of the filter material, the high retention capacity and good cleanability of inert filtrate are key factors.

Following the qualification of the SMF material for hydraulic filtration applications and APC, the first promising applications are now emerging in the field of hot gas dedusting. Filter elements are produced in prototype manufacturing processes for the first tests that go beyond material tests. Filter cartridges with ø 130 mm, 160 mm and 325 mm up to 3 m in length are currently being tested and further developed for hot gas filtration to enable lengths of up to approx. 9 m. Tests have shown...

Learn More at FILTECH 2023 Conference - Register Now!

Impact of conducting filter media on the performance of pulse-jet filtration assisted with pre-charger

A. Mukhopadhyay*, A.K. Choudhary, National Institute of Technology Jalandhar; S. Dutta, Bannari Amman Institute of Technology, C. C. Reddy, Indian Institute of Technology Ropar, India

Electrostatic precipitators and fibrous filters are the most commonly used gas cleaning devices for the removal of particulate matter in power plants and industries. However, the collection efficiency of electrostatic precipitators decreases for particles smaller than 1 μm. Fibrous filters provide higher filtration efficiency for particles of this size, but the pressure drop is higher, and additional energy is needed to supply the outlet fan. Recently, special attention from engineers has been given to hybrid constructions, which apply electrostatic fields and forces in order to improve the performance of bag filters. However, to date, ESP-assisted fabric filter has limited use because of the increased complexity of the system, larger size, filter media may be easily damaged by sparks, and replacing filter bag may be difficult due to the existence of extra parts such as electrodes in complex design, or cost reason may exist due to the additional parts.

The present work proposes simplifying the construction of an electrostatic-assisted fabric filter system by using a pre-charger for efficient control of industrial air pollution. In view of the above, the current paper is aimed at studying the pulse jet filtration behavior assisted with a pre-charger using fly ash aerosol...

Learn More at FILTECH 2023 Conference - Register Now!


G06 - Adsorption

Day: 15 February 2023
Time: 09:00 - 10:15 h
Room 4

Session Chair:
Thomas Heininger

Improvement of mechanical properties maintaining adsorption capacity of permanganate-based media for the removal of indoor air pollutants

I. Merino, S. Palekar*, A. Doche, A. Puig, E. Sunye, Bioconservacion, S.A., Spain

Several health effects are associated with the air quality and the presence of indoor generated pollutants, including NOx, volatile organic compounds (VOCs), formaldehyde, gases generated from cleaning products, etc. Considering that the world´s population generally spends 90% of their time indoors, it is highly important to eliminate indoor pollutants and particles. For this reason, the addition of gas filtration media in indoor purifiers is considerably increasing. All these pollutants can be removed with a media blend consisting of activated carbon and permanganate-based media.

The minimization of dust release from pellets is especially necessary for indoor air quality equipment in order to reduce the blockage rate of particle filters and increase the frequency of change of these particle filters. This implies a decrease in cost due to maintenance or replacement of particle filters. Higher dust generation will also increase the pressure drop, increasing the energy consumption and the operation cost. The minimization of the dust generated from the pellets is a must. The hardness is another important factor to consider for the assembly process of the filters containing the media, especially for automatic filling systems, since low hardness can cause issues and dust generation during the filling process of the filters.

The increase in hardness, decrease in dust and improvement of other mechanical parameters need to be adjusted to obtain a filtration product that complies with the operation conditions without clogging the particle filters. The most important development challenge of such robust product relies on the adsorption capacity, which is often significantly sacrificed to obtain better mechanical properties. Most of the already commercialized permanganate-based spheres, which show strong mechanical properties, present a sharp decrease in capacity of up to 70% compared to standard permanganate spheres with average mechanical properties and dust release.

This work presents the development of a novel formula with both strong mechanical properties, low dust generation and high adsorption capacity. Several laboratory and industrial tests have been done to demonstrate...

Learn More at FILTECH 2023 Conference - Register Now!

Multi-sorbent gas adsorption media for complex application demands for indoor air quality and electrical vehicle intake


Process managers, consumers, and automobile operators are increasingly aware that airborne molecular contaminants (AMC) are problematic to production yields and the air we breathe in cars and buildings. Since these airborne contaminants are molecular in size, sorbent technologies must correctly match both the size of the molecules and the concentration levels inherent to the application conditions.

We will demonstrate by presentation of data that corresponds to specific application conditions how small mesh granular activated carbon (GAC) can be formatted in

non-woven structures to efficiently capture molecular contaminants. Adsorption data will be shared illustrating the removal of common gases such as VOC's, NHC, SOx, NOx, and aldehydes. These data will be correlated to flow conditions that match such applications as room air cleaners, HVAC systems, and fuel cell filters.

Finally, we will exhibit composite non-woven structures designed to serve dual purposes. This includes the layering of sorbent structures impregnated for different purposes; as well as sorbent media that is laminated to media designed for particulate removal. This segment demonstrates multi-layer composite design that can optimize system design within a smaller footprint...

Learn More at FILTECH 2023 Conference - Register Now!

Process air cleaning in the battery manufacturing

S. Holfeld*, R. Heidenreich, Institute of Air Handling and Refrigeration (ILK), Germany

The promotion of e-mobility and the need of energy storage leads to a high demand for corresponding battery solutions in many industrialized countries. The production of batteries is therefore the focus of many development activities.

In the production of lithium-ion batteries, a key industry in the energy transition with enormous growth potential, such production areas are the process steps "trimming" to "electrolyte filling". To keep a high battery performance the handling of lithium-containing materials requires a very clean and dry environment with dew points well below -40°C. To ensure an economic production the dry air have to be recirculated including a high efficiency filtration. The laser cutting process is ideal for sizing the electrodes, but this also produces large quantities of ultra-fine particles and an amount of trace gases.

These trace gases obviously include components that causes damages at the air drying system and could influence the product quality.

So it is part of a currently ILK research project to find suitable solutions to separate these components in an economic way. The project will

  • determine main trace components that causes or could causes damages at the production line and/or the product,
  • find suitable sorption technologies able to reduce them and
  • build up an air cleaning prototype to verify the function also in real production environmental.

In the presentation first results of this project will be discussed...

Learn More at FILTECH 2023 Conference - Register Now!


L05 - Microplastic Filtration and Filtration of highly Diluted Slurries

Day: 15 February 2023
Time: 09:00 - 10:15 h
Room 1

Session Chair:
Prof. Urs A. Peuker

Microplastics from tire wear – Filtration in the field

D. Herper*, GKD - Gebr. Kufferath AG, Germany

Plastics and their emission into the environment are one of the global challenges humanity is facing in our current century. Especially small polymer particles in the environment, known as microplastics, have caught the attention of politics, scientists and the public alike. One of the main sources of microplastics is traffic. The use of synthetic rubber tires is essential for all kinds of land based mobility. Unfortunately tires wear during their usage. The particles generated in this wearing process are considered to be microplastics. They are emitted into the environment and the majority is washed away by rain ending up in sewer systems. Down to the present day it is unknown, what tire wear particles look like and what sizes or even particle size distributions they show. The Technical University Berlin, GKD and ARIS are working on the development of suitable filter systems to be implemented on public roads in order to reduce the emission of tire wear to environment....

Learn More at FILTECH 2023 Conference - Register Now!

A novel precoat filtration method using fine bubbles

M. Iwata*, K. Yagishita, S. Oguri, T. Kitagawa, H. Yagishita, K. Yagishita, Sanshin Mfg. Co., Ltd., Japan

In constant rate batch microfiltration using the precoat filtration method, the filtration cycle consists of the following steps. First, the diatomaceous earth slurry is filtered to form a precoat layer. Next, the dilute suspension to be filtered is fed over the precoat layer at a constant rate. The filtration pressure is gradually increased as the filtration proceeds. When the filtration pressure reaches a predetermined value, filtration is interrupted, the precoat layer is backwashed, and the next precoat step is started.

We have proposed a novel method of preparing the precoat layer using a suspension of fine air bubbles. Using this method, the amount of filtrate obtained in one filtration cycle is considerably larger than that of the conventional method without fine bubbles. In other words, the amount of solid particles captured in one filtration cycle is much higher than in the conventional method, reducing the consumption of diatomaceous earth.

In this study, the role of fine bubbles in preparing the precoat layer was clarified. Iron hydroxide slurry...

Learn More at FILTECH 2023 Conference - Register Now!

Capacity of nonwoven filter layers for use in automatic filters

T. Buchwald*, U.A.Peuker, Technical University Bergakademie Freiberg, Germany

Automatic filters are used whenever large volumes of liquids need tob e cleaned from a relatively low solids content, usually in the ppm-range. Predominantly, filter screens are used, with square weaves reaching a technological limit at 20 µm. Dutch weaves are therefore used to decrease the separation size to around 5 to 10 µm. To further lower this cutoff size, layers of nonwovens are increasingly introduced as additional filter layers to lower the cut size even further, with an additional benefit of increased dirt-holding capacity.

Increased capacity of a nonwoven filter layer comes at the cost of increased blocking of the filter layer with increased starting resistance and lowered throughput per filtration cycle. To investigate the behavior of nonwovens in clarifying filtration, nonwovens made of PE or PP fibers were made as compound with a stainless steel wire mesh as intermediate support layer. These filter media were tested regarding their clean resistance, the behavior during multiple filtration cycles up to about 120 cycles, and their dirt-holding capacity.

The presentation explains how to properly describe the characteristic behavior of filter media necessary to evaluate their use in automatic filters. Results from the filter media compounds are shown and pros and cons of their use as an alternative in clarifying filtration are discussed...

Learn More at FILTECH 2023 Conference - Register Now!


L06 - Decanter Centrifuges

Day: 15 February 2023
Time: 09:00 - 10:15 h
Room 2

Session Chair:
Dr. Marco Gleiß

Parametric study of centrifugal dewatering of flocculated activated sludges with a lab screw decanter

P. Ginisty*, IFTS - Institute of Filtration & Techniques of Separation, France

Solid bowl centrifuges are classically used in wastewater treatment plants for a thickening and dewatering purpose, enhanced by conditioning to obtain an efficient separation process between water and solids. Treatment optimization is very empirical as operators should continuously adapt the machines performances to sludge and flocs properties and variations of these properties over time. Performances and optimal setting parameters are often difficult to predict owing to complex mechanisms occurring during separation, high shear stresses undergone by flocs and sludge variability (nature, composition, behavior). Some authors [1] tried to link the performances to sludge and flocs properties but controversial effects are often observed. Others [2] use validated solid bowl centrifugation model to foresee the effects of operating parameters including the bowl rotating speed, weir height, the differential speed, feed rate and characteristics and results focus more on particle but results fail to take into account some parameters like backflows, particle-particle interactions, solids breakup….

Some improvements were brought by recent developments concerning the use of a lab scale centrifuge [3] with introduction of the polymer for sludge flocculation at the entry of the machine (figure 1). Results highlight the influence of...

Learn More at FILTECH 2023 Conference - Register Now!

Direct recycling of lithium-ion battery cathode materials from aqueous suspension by centrifugation

T. Yildiz*, M. Gleiß, H. Nirschl, Karlsruhe Institute of Technology (KIT), Germany

In the context of progressing e-mobility, the demand for functional materials of the lithium-ion battery is increasing. Due to the limited availability of the metallic compounds, especially of the cathode active material, the recycling of the functional materials of end-of-life batteries becomes more and more essential. Currently, there are already two established techniques for the recycling of lithium-ion batteries: pyrometallurgical and hydrometallurgical recycling. In the case of pyrometallurgical recycling, thermal decomposition of end-of-life batteries takes place under high energy input, recovering metals as alloys and slag. For hydrometallurgical recycling, the components are recovered as elements by precipitation and flocculation reactions using high amounts of chemicals. Direct battery recycling is a novel approach that takes advantage of the different physical properties of the materials and thus recovers the materials by mechanical treatment processes while retaining the particulate structure and the material function. Therefore, direct battery recycling is a more efficient and environmentally friendly recovery process in contrast to the established processes. One possible mechanical recycling process route involves electrohydraulic shredding of the end-of-life batteries in water and subsequent sorting by coarse fragments (e.g. conductor foils and housing components) and the fine-particulate black mass (active materials and carbon black) by wet sieving. This is followed by a density-based fractionation of the black mass particles into active material and carbon black from the aqueous suspension in a decanter centrifuge to recover the materials for the direct production of new battery cells. Before analyzing the fractionation of the complex black mass, the fractionation of the anode and cathode materials by centrifugation will be investigated separately. In the talk, results of an experimental study concerning the fractionation of an aqueous cathode suspension into cathode active material and carbon black in a centrifugal field will be shown...

Learn More at FILTECH 2023 Conference - Register Now!

Development of a dynamic grey box model for a digital twin of decanter centrifuges

O. Zhai*, M. Gleiß, H. Nirschl, Karlsruhe Institute of Technology (KIT), Germany

Continuous solid bowl centrifuges like decanter centrifuges are widely used in the chemical and minerals processing industry to separate finely dispersed particles from a continuous liquid phase. When designing the devices, the understanding of the physical behavior is crucial. The state-of-the-art method to design decanter centrifuges is based on stationary models which are strongly simplified. Dynamic events within the apparatus, for example, the sediment buildup and consolidation, are not considered by these models. For this reason, manufactures have to do time consuming pilot scale experiments and derive their own correction factors to counteract the inaccuracies made by the models.

A promising alternative method for dimensioning, scale up and model predictive control of decanter centrifuges is using a digital twin. The digital twin consists of a hybrid model (grey box model) which combines a mechanistic model (white box model) and a data driven model (black box model) to describe the solid-liquid separation in decanter centrifuges. Hereby, the mechanistic model uses empirically derived material functions to describe the settling behavior, the sediment consolidation and the sediment transport. Some physical effects, for example, local flow effects at deep pool depths, are not considered and thus the mechanistic model does not reflect the whole process. To counteract this, a non-parametric model (e.g., a neural network) is used to increase the accuracy of the model. Experimentally determined data is utilized to train the data driven model that is then able to correct the errors made by the mechanistic model and thus consider physical effects that are not yet described. While there are hybrid models to describe decanter centrifuges they are all static which means the model is trained once and has to be completely retrained if it needs to learn new data. A dynamic hybrid model on the other hand is able to continuously learn new data to improve the model’s accuracy without retraining the whole model which is time consuming. Making machine leaning models to continuously learn data is a big challenge as they tend to forget old data when learning new data.

In this talk, the development of a dynamic grey box model to describe a decanter centrifuge is presented...

Learn More at FILTECH 2023 Conference - Register Now!


K03 - Keynote Lecture III

Day: 15 February 2023
Time: 10:45 - 12:00 h
Room 1

Session Chair:
Prof. Hermann Nirschl

Description of particle interactions in solid-fluid separation processes by CFD-DEM coupling method

Prof. Dr.-Ing. Sergiy Antonyuk, University of Kaiserslautern-Landau, Germany

In many solid-fluid separation processes, the dynamical interactions between particles and particles with separation media take place and have a major influence on the separation efficiency and the resulting pressure drop. In depth filtration, the particle separation depends on the collision mechanisms of particles with fibers and local flow conditions in the microstructure of nonwoven. The formation and consolidation of compressible filer cake in the surface filtration are influenced by the adhesive interactions, contact deformation and breakage of particles. Therefore the understanding of microscopical particle interactions in fluid flow is essential to describe the separation processes.

The coupling of discrete element method (DEM) and computational fluid dynamics (CFD) is a very powerful tool for the numerical study of dynamical particle interactions and separation mechanisms in fluid. This contribution first gives a brief overview on the physical contact models which can be used in CFD-DEM. The established experimental methods for the parameter estimation and validation of models are discussed.

The focus is particularly on the description of deformation mechanisms of particles in compressible filter cake. Plastic deformation of soft particles can lead to immense porosity changes of the filter cake, which leads to significantly higher pressure differences during filtration compared to stiff and elastic particle systems. However, only a few contact models for elastic-plastic particles and numerical considerations regarding compressibility can be found in current literature. Therefore, an elastic-plastic contact model was developed, experimentally validated and implemented in DEM. As one of the most important physical and mechanical properties of particles, their restitution coefficients were measured with collision experiments of particles in liquid and air with a developed experimental setup. The effects of lubrication forces and surface morphology on the dynamical contact behavior are studied and considered in the contact model (Figure 1). The nano and tribo indentation methods were adapted for the measurement of the friction and deformation behavior of fine single particles in liquid (Figure 1). The filter cake formation and compressibility were studied with the developed and experimentally validated contact model by variation of the particle properties with respect of the elasticity and plasticity (Figure 2). The micromechanical interactions inside of the filer cake and porosity distribution were analyzed. Moreover, the influence of process properties as flow pressure and volume flow on the filtration process were investigated.

Learn More at FILTECH 2023 Conference - Register Now!


F01 - Sustainable Filter Elements and Media

Day: 15 February 2023
Time: 10:45 - 12:00 h
Room 3

Session Chair:
Dr. Martin Lehmann

Reducing the carbon footprint of filter elements with design, process and material optimizations by means of life cycle assessments (LCA)

L. Spelter*, M. Hirt, C. Oprisch, T. Müller, MANN+HUMMEL GmbH, Germany; S. Arora, MANN+HUMMEL USA INC., USA; J. Zenner, MANN+HUMMEL FRANCE S.A.S., France

The European Commission has defined a climate and energy framework to reduce the greenhouse gas emissions within the running decade significantly and to reach climate-neutrality by 2050. Specific targets have been set for 2030: at least a cut of 40 % of greenhouse gas emissions is required (compared to 1990 levels) and a share of 32 % of renewable energies is demanded.

For reducing the greenhouse gas emissions of a company, it is necessary to understand the different contributing factors within the e.g. production but as well of the supply chain and later usage of the products. The life cycle assessment (LCA) is a method to determine these effects of a product on the environment. The LCA may further include e.g. water footprint and social impacts. The emissions are generally classified into scope 1, 2 and 3. Scope 1 are emissions that are directly caused by the company producing the part such as e.g. gas used to heat ovens. Scope 2 are emissions that are caused by the energy that is used but produced externally such as electrical energy taken from a grid. All emissions caused outside the company but that are affecting the carbon footprint (CFP) of the product are scope 3, these are e.g. the carbon footprint of purchased parts or the usage of the product by the customer.

For a filter element the dominating contributing factors are scope 1 and 3, with a major contribution by scope 3. The production of filter media and other raw materials such as polyol and plastics, that are used for sealings or as end plates, are the main drivers for the carbon footprint of a filter element. Thus, a very important aspect is the input data quality to determine scope 3.

In this contribution we will show the LCA for exemplary filter elements and identify the main influencing parameters on the CO2 footprint of these products. A specific focus will be put on the impact of the filter media comparing synthetic vs. cellulose materials...

Learn More at FILTECH 2023 Conference - Register Now!

On the road towards sustainable filtration - Aspects of automotive filter element recycling and disposal

T. Müller*, L. Spelter, F. Keller, MANN+HUMMEL GmbH, Ludwigsburg, Germany

Sustainability aspects are rapidly gaining importance in the automotive industry. This development is driven by the evolving legal framework (e.g. the European Green Deal), end-customer awareness and also by sustainability roadmaps of vehicle manufacturers (OEMs) and their suppliers. The public focus is on CO2 emissions and the ensuing technology shift. However, a transition from today’s (mostly) linear economy towards circular economy is necessary to decouple economic growth from the extraction and use of natural resources [1] as well as a prerequisite for climate neutrality [2].

Figures like the global plastic recycling rate of only 9% for 2019 [3] versus 49% landfill and 22% mismanaged & uncollected plastic waste, respectively, signify that there are still major challenges ahead in the pursuit of “closing the loop”. The related technical, economic and political transition will also drastically affect the filtration industry. The way filter systems and elements are designed, produced, used and disposed of will change significantly over the next 10 to 20 years.

The aim of the present paper is to provide an overview of the key legal, technical and economic aspects of en-of-life treatment of filter elements. We present the current state of the art of filter element disposal and recycling as well as the regulatory framework in the EU. Also, we share insights into challenges and controversies the automotive filtration industry will be facing on its road to circular economy...

Learn More at FILTECH 2023 Conference - Register Now!

A woven wire mesh for energy-efficient filtration processes

M. Müller*, Spörl KG, Germany

The filter medium is the core element of every filter unit. To select a filter medium for a specific filtration task, beside commercial aspects and the ability to form the medium into the desired design without damaging it, the main request is to ensure, that the medium complies with the filtration requirements of the process. Thus, the pore size needs to be selected so small that the desired purity of the filtrate is achieved. At the same time, the filter medium needs to be able to withstand the chemical, thermal and mechanical stresses which occur. For a resource-saving filtration process, the filter medium should have a high permeability and a large dirt-holding capacity, which is associated with a long service life. For filtration processes with a large dirt load which has to be separated, the filter medium should be easily cleaned e. g. by pulse-jet or back flushing.

Due to their high chemical, thermal and mechanical resistance, woven wire meshes as metallic filter media can be used in demanding operating conditions, for example in the form of high process pressures and temperatures or sharp-edges particles which have to be deposited. With their narrow pore size distribution woven wire cloths guarantee an excellent separation and classifying accuracy. Depending on the combination of the warp wires and the weft wires during the weaving process, the production of different types of weave with different aperture sizes and filtration behaviors is possible.

Dutch Twilled Weaves as one of the weaving types of woven wire meshes are established filter media for the deposition of finest particles down to a geometric pore size of 5µm and to realize highest separation performances already in the unloaded state. To achieve these small pore cross-sections, the weft wires need to be woven as closely together as possible. This results in a fabric with a low porosity, low free passage area and low number of pores, and thus a high pressure loss and power consumption of the filtration process. Furthermore, the narrowest pore cross section is located inside the fabric, which is why this weaving type is very difficult to clean. Frequent replacements of the filter elements made from them is necessary, which leads to high maintenance costs and long plant downtimes.

An alternative weaving type to produce finest wire meshes are the so called Betamesh-PLUS fabrics. In these plain weave fabrics, the wire diameters of the warp and weft as well as the pitches are combined in such a way that these fabrics are characterized by a high permeability, a high dirt-holding capacity and ideal back flushing properties. Until now, these fabrics could only be woven for pore sizes of approx. 10µm and coarser. By adapting the weaving technology and the wires used, it has yet been possible to produce this advantageous weaving type for geometric pore sizes down to 5µm. As an example, Figure 1 shows...

Learn More at FILTECH 2023 Conference - Register Now!


L07 - Filter Centrifuges and Hydrocyclones

Day: 15 February 2023
Time: 10:45 - 12:00 h
Room 2

Session Chair:
Dr. Pascal Ginisty

Numerical and experimental investigation of the particle segregation during centrifugal filtration

F. Krull*, P. Lösch, S. Antonyuk, University of Kaiserslautern-Landau; S. Boldt, D. Krause, D. Lerche, LUM GmbH, Germany

To achieve the best filterability for a special application, a filter material with tailor-made structure has to be developed. For the design and dimensioning of filtration processes, standardized laboratory tests are usually performed. A new possibility for filtration experiments is to perform the filtration experiments by means of analytical photo-centrifugation filtration (ACF) which allows a simple and fast membrane characterization and filterability with suspensions of about 1 ml. A special developed filtration cell holds the suspension that has to be filtered, the filter media and as well as the resulting filtrate. Furthermore, by adjusting the instrument parameter by applying different rotor speeds (influencing the applied pressure) at different time stages or temperature profiles during one experimental run makes the design very flexible. ACF by a multi-sample photo-centrifuge is based on continuous in-situ measurement of space resolved light transmission monitoring the volume increase of the filtrate at the bottom of the cell by STEP-Technology®. During a filtration in a centrifugal field, a size dependent acceleration acts on the particles which influences the filter cake built-up and thus the flow resistance. To get an in-depth understanding of the filtration process, a coupled CFD (Computational Fluid Dynamics) – DEM (Discrete Element Method)-simulation can be used.

In this contribution the acting centrifugal force was implemented in a multiphase Volume-of-Fluid solver (CFD) as well as in the DEM to describe the particle motion during the ACF in a new developed ACF cell. The simulation parameters were calibrated and the simulations were validated with experiments...

Learn More at FILTECH 2023 Conference - Register Now!

Troubleshooting and optimization of industrial filter centrifuges with minimal experimental effort by using the CENTRISTAR software

I. Nicolaou*, NIKIFOS Ltd, Cyprus

The reliable and optimal operation of Batch Filter Centrifuges is in many cases a challenge especially when the given centrifuge does not give the expected performance: Low productivity (solids mass throughput) and/or too high cake moisture content and/or too high contents of wash out substance in the discharged cake. The judgment of the performance of Batch Filter Centrifuges is an extremely important but also very difficult task. Questions like: Is maybe the size of the centrifuge (filter area) too small for the expected performance? Is the given suspension with the given solids content suitable for the filter centrifuge? Or/and maybe the operational settings like rotational speeds for the different steps, cake height, wash liquid amount, deliquoring (spinning) time, suspension and wash liquid rates are not selected in a proper way? And which should be the settings for an optimal performance? But how we can know what is the optimal performance for the given suspension and the given centrifuge? All or some of the above questions cannot be answered or cannot be answered in a satisfactory way without tools, which enable the reliable calculation of the performance parameters for the given suspension, the given centrifuge geometry and given settings parameters.

CENTRISTAR is a novel software, which uses practice oriented and physically based mathematical models, which consider the complex phenomenology of all process steps taking place during one centrifuge cycle. The reliability is given due to the integrated analysis modules which enable the detection and correction of test data and the determination of efficiency parameters for cake formation, washing and deliquoring as necessary material parameters for the centrifuge performance calculation. In this paper, a method is presented, which allows for the first time the input of known settings and performance data of an industrial centrifuge and the determination of its efficiency parameters. Based on the determined efficiency values, explanations are given, how the centrifuge performance can be judged and optimized...

Learn More at FILTECH 2023 Conference - Register Now!

Design of hydrocyclones with minimal experimental effort by using the CYCLONPLUS Software

I. Nicolaou*, NIKIFOS Ltd, Cyprus

In this paper, a new method for the reliable Design of Hydrocyclones with minimal experimental effort by using the novel software CYCLONPLUS is presented. The reliability is due to practice oriented mathematical models, which consider the complex phenomenology by the use of adaptation parameters. The seven adaptation parameters are specific for the system suspension and hydrocyclone family. To one hydrocyclone family belong apparatuses with different diameters of the cylindrical part but with the same specific geometrical parameters: length to diameter (L/D), cylindrical length to diameter (l/D), inlet diameter to cyclone diameter (Di/D) as well as overflow diameter to cyclone diameter (Do/D). All seven adaptation parameters can be determined from only 3 laboratory experiments by using the Analysis module of the CYCLONPLUS software. From every test the following parameters have to be measured and entered in the Analysis module: Feed und underflow volume rates (Q, Qu), Pressure drop (Dp), underflow orifice diameter (Du) and solids mass content of the overflow (cmo). Due to the theory-based diagrams of the Analysis module, the quality of the measurements can be judged, and only correct measurements can be used for the determination of the above mentioned seven adaptation parameters...

Learn More at FILTECH 2023 Conference - Register Now!


M01 - Water Treatment

Day: 15 February 2023
Time: 10:45 - 12:00 h
Room 4

Session Chair:
Prof. Wilhelm Höflinger

Challenges in introducing innovations in membrane technology-based applications with a focus on seawater desalination with reverse osmosis

T. Peters*, Membrane Consulting, Germany

Many problems that we are currently facing worldwide can be summarized with a few words: Increasing demand and decreasing resources. This applies especially to the supply of clean and affordable water for human consumption, for food production or for the needs of different areas in industry. As it is related to population growth, the demand for beneficial water will keep increasing year by year, while the availability of natural water resources will remain the same or even decrease due to different influences.

Possible solutions for securing the water procurement in the future include the conscious use of potable water, the use of adequately purified municipal or industrial wastewater, and finally the production of drinking water from salty sources like brackish water or seawater. The desalination of seawater with the pressure driven membrane process reverse osmosis (RO) is the leading technology for new desalination installations in this regard. Currently about 16,000 desalination plants are involved in the world’s desalination production capacity, with this process accounting for about 70%, or about 65 million m³ of drinking water per day.

Influenced in part by the technological advantage that RO plants can be built to a replicable strictly modular design, and by savings due to economy of scale, a trend toward larger desalination plants has been observed over the last decade. While 10 years ago, plants producing about 100,000 m³/day were in demand, the necessity to meet the increasing demand for affordable high-quality water has led to a significant increase in the size of these plants. However, as projects have grown in size and delivery models have become more complicated, identifying the decision maker in a desalination project has become much more challenging today than it was 15 to 20 years ago. Many more details regarding design, components, and processes, including legal aspects, as well as impacts on the environmental footprint need to be thoroughly analyzed to achieve traceable and stable long-term results.

This is particularly true if innovative plant components or alternative processing concepts are offered...

Learn More at FILTECH 2023 Conference - Register Now!

Dual freshwater and salts harvesting from brine via photothermal membrane

H.M. Abdel-Ghafar*, E.A. Abdel-Aal, M. T. Elbossy, Central Metallurgical Research and Development Institute (CMRDI), Egypt

Sunlight is the ultimate energy source on the earth. Solar-driven evaporation via photothermal membranes is considered a sustainable strategy for clean water production through desalination and wastewater treatment to overcome the global challenge of water scarcity. Brine is a high-concentrated solution of salts in water, mainly produced from desalination plants. There are limited thermal-based desalination techniques that can recover freshwater from brine with high intensive energy consumption because of the highly concentrated TDS.

Herein, we developed a self-cleaning membrane with capability of simultaneous generation of freshwater and salts from brine. Different pyrrole concentrations (0, 5, 10, 15, 20, and 25 μL), types of substrate (PVDF, woven and non-woven fabric), oxidizing agents (NH4)2S2O8, FeCl3, CuCl3, KMnO4, and Na2Cr2O7), and the concentration of oxidizing agent (0.1, 0.5, and 1.0 M), at 80 ℃ for 1 h were investigated. The optimized facial deposition strategy resulted in...

Learn More at FILTECH 2023 Conference - Register Now!

Activated carbon to improve the performance of membrane processes for the extraction and elimination of methylene blue pollutant

S. Oukkass, R. Ouchn, I. Mechnou, I. El Yaakouby, M. Hlaibi*, University Hassan II, Morocco; L. Lebrun, University of Rouen, France

In the last few years, membrane technologies have experienced a considerable growth, due to their numerous uses and their advantages over other conventional techniques. The membrane processes present today an important research topic, especially affinity polymer membranes, very adapted to oriented processes. Methylene blue is one of the most widely used dyes in various fields such as chemistry, medicine, dentistry and the dye industry. Our objective is to develop a polymeric inclusion membrane for methylene blue extraction and recovery processes, assisted by activated carbon. We developed a membrane based on a mixed polymer support, polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP), and the amphiphilic molecule Tween 20 (TW20) as extractive agent (EA). In order to quantify the performance of developed membrane, macroscopic parameters such as initial flux J0, and permeability P, as well as microscopic parameters such as association constant Kass, and diffusion apparent coefficient D*, were determined. Then, we determined the activation parameters, energy (Ea), enthalpy (ΔH#ass), and entropy (ΔS#). Finally, we studied the effect of activated carbon on the evolution of processes carried out and the performance of the membrane, and we observe a very clear improvement. The obtained results indicate that...

Learn More at FILTECH 2023 Conference - Register Now!


K04 - Keynote Lecture IV

Day: 15 February 2023
Time: 13:00 - 14:15 h
Room 1

Session Chair:
Dr. Karsten Keller

Mineral tailings filtration: lessons learnt from wastewater sludge filtration

Dr.-Ing. Anthony Stickland, University of Melbourne, Australia

Mineral ore processing produces tailings at an enormous scale that is increasing with demand and decreasing ore grades. Decreasing ore grades also require additional grinding to liberate valuable minerals, resulting in more fine particles in the tailings. The minerals industry is shifting to dry stacking of tailings to reduce the environmental risk posed by tailings dams. For fine particle suspensions, dry stacking requires high pressure filtration to achieve stackable cake moisture contents, which has the added benefit recovering additional process water. The filter presses required to process tailings at the world’s largest mines push the limits of plate size and minimal handling time to reduce capital and operating costs. However, these behemoths do not solve some of the underlying fundamental problems with filter presses such as batch processing, fixed cavity width, and the use of filter cloths. Cloths need to be regularly cleaned and replaced, becoming waste if they can’t be repurposed or recycled. Novel technologies are required to meet the challenge of economically viable tailings dewatering within a sustainable minerals industry. This presentation will explore some of the challenges of fine particle filtration that face the minerals processing industry. The fine particles reduce both the rate and equilibrium extent of filtration; thus, it is illuminating to explore three lessons learnt from the filtration of wastewater sludges, which are much worse than tailings with respect to compressibility and permeability. Firstly, filtration modelling of sludges shows that optimal use of filtration area and reduction of auxiliary equipment can be achieved using continuous rather than batch filters. Secondly, the filtration path length for a given set of processing conditions and material properties can be very small and will change with material dewaterability. Therefore, thin filter cakes and adjustable operating conditions allow filters to maximise throughput for varying feed, such as when the mineralogy of the ore changes. Lastly, incorporating shear during filtration improves the performance. High-pressure technologies that meet these criteria have the potential to provide the innovation evolution required by the minerals industry. A bonus feature is if the technology doesn’t use filter cloths and thus eliminates this source of complexity, downtime, and waste.

Learn More at FILTECH 2023 Conference - Register Now!


F02 - Smart Filter Element Development and Production

Day: 15 February 2023
Time: 13:00 - 14:15 h
Room 3

Session Chair:
Dr. Lars Spelter

Smart filter element development – Applied machine learning for optimized element layouts

T. Gose*, C. Schulz, F. Keller, J. Ziegler, MANN+HUMMEL GmbH; C. Hitzke , S. Zöllner, MANN+HUMMEL Innenraumfilter GmbH & Co. KG, Germany

In recent years the importance of data and its’ interpretation has been grown significantly in development processes. Modern methods of Data Sciences enable developers to discover hidden insights in existing datasets or to create new datasets well suited for machine learning. Emerging “data lake” structures can consist of measurement data as well as simulation data or even mixed data from various sources as long as it adds up to the overall knowledge.1

The present talk will discuss challenges in the application of machine learning for optimized filter element layouts.2,3 The goal is to enable developers to find optimal filter designs within seconds instead of hours or days. The optimal filter element design needs to consider the design space and customer specifications, amongst others. Looking on the workflow, the seamless integration of this novel design approach into the whole development process is a core requirement.

The goal of the approach is to maximize the use of the results of a multi-parameter optimization by providing these in an easy and explorative way to the developer being the domain expert.4 This combines challenges of different disciplines as besides model quality also user experience and conformity to the matured automotive development processes need to be satisfied.5 From a technical point of view the mentioned multi-parameter optimization is the backbone of the tool shown in the talk. The optimization parameter can vary and e.g. be pressure drop, dust holding capacity or media area, amongst others.

Model quality strongly depends on the input data quality and the covered parameter range. “Much data” does not necessarily mean sufficient data for machine learning...

Learn More at FILTECH 2023 Conference - Register Now!

From virtual production to real filter media samples

F. J. Hahn*, T. Gose, L. Spelter, K. Riedinger, F. Keller, MANN+HUMMEL GmbH; A. Schmeißer, W. Arne, R. Wegener, Fraunhofer Institute for Industrial Mathematics (ITWM), Germany

The emission of fine dust from industrial processes and traffic poses a threat to public health as well as contamination-sensitive manufacturing technology and clean rooms. This necessitates the provision of clean indoor air and therefore requires highly efficient air filter media. Considering the rise in energy cost and the requirement of worldwide CO2 reduction the energy consumption of air filters becomes increasingly relevant. Developing filter media featuring both highest levels of filtration efficiency and lowest possible pressure drop represents an optimization challenge, as both design goals are conflicting.

To tackle such challenges, virtual filter media development has proven to be a valuable tool. In a simulation driven development loop virtual material prototypes of filter media can be specifically designed to yield optimal performance for individual applications. Commonly, these virtual material models are based on a set of statistical parameters describing the structure of fibrous media. However, the producibility of the virtual material structure in a real world production process is not inherently accounted for. Thus, the realization of virtually predicted optimal filter media prototypes requires extensive validation in trial runs and may sometimes not be achievable.

Within the scope of a publicly funded research project we address this limitation by means of a novel, holistic concept for virtual filter media development at the example of spunblown filter media. In our approach, the conventional parametric material model is substituted by a physical simulation model of the media production process. Hereby, the influence of relevant process parameters on the properties of the resulting media structure is directly captured within the virtual material model.

The adherence of the virtual material model to the production process is a key factor for the transferability of virtually predicted filter media designs to real world production. Therefore...

Learn More at FILTECH 2023 Conference - Register Now!

Three dimensional AI-Segmentation of synthetic filter media

P. Eichheimer, A. Grießer*, Math2Market GmbH; K.M. Höss, F. Hahn, C. Schulz, MANN+HUMMEL GmbH, Germany; A. PS, MANN+HUMMEL, India

In recent years the usage of artificial intelligence (AI) tools in image processing and analysis has gained significant interest and undergone major improvements. Several techniques, including neural networks, have been used to manipulate and analyze fiber-based images, which in the past required intensive usage of image filters. MANN+HUMMEL has gained significant expertise in the microstructure characterization of fiber-based filter media within the last years [1]. Mainly manual and OTSU-based threshold methods are being used nowadays to segment the µCT scans into voxel meshes suitable for microstructure characterization and microstructure simulation. Often, these µCT scans pose additional challenges. For example: for filter media with multiple fiber materials, the lower-density fiber material is often harder to distinguish from background noise than the higher-density fiber material, represented by higher brightness values. In addition, high-resolution µCT scans (resolution < 2 µm/Vox) frequently exhibit artifacts where the fiber core is represented with lower brightness values than the fiber surface. This effect is particularly pronounced for so-called shots in meltblown fiber media (Figure 1), i.e., irregular and clumped material accumulations formed by fibers melting together in the manufacturing process. The resulting segmentation leads to hollow fibers and shots that make the voxel mesh unsuitable for microstructure characterization and simulation. Following the segmentation, it is possible to close the hollow fiber structure with image processing algorithms for standard hollow fibers with round cross-sections. However, these image processing algorithms reach their limits and lead to strongly deviating material distributions for more complex microstructures with hollow shots, hollow fibers with irregular cross-sections, or filter media with multiple fiber types.

A solution for these problems may lie in the promising AI-segmentation [2]. In the context of method development and innovative material analysis, the potential of this still relatively young technology, to segment problematic µCT-scans of complex fiber structures realistically, was tested and assessed on various use cases. First, parts of the µCT-scan are sparsely labeled manually. This labeled data is then used to train a 3D-UNET [3] in the simulation software GeoDict. 3D-UNET is a fully convolutional deep neural network, offering advantages over 2D-UNET approaches by incorporating the 3D context of the image. Finally, the trained neural network is applied to the full µCT-scan to obtain the final segmentation.

This presentation compares the results of AI-Segmentation on different microstructures with the segmentation based on OTSU thresholding and morphological operations. Visual comparison of the resulting voxel meshes of both methods with the µCT scan, as well as validation of the resulting microstructure characterization and microstructure simulation by material testing and simulation using the FlowDict module of GeoDict, are discussed and used to make the applicability of the new method comprehensible.

Learn More at FILTECH 2023 Conference - Register Now!


G07 - Vapor, Mist and Droplet Separation

Day: 15 February 2023
Time: 13:00 - 14:15 h
Room 2

Session Chair:
Prof. Andrzej Krasinski

Separation of aerosols inducing localized condensation of vapors

J. Vallejo, M. Dalmasso, M.J. Rubio, J. Marval, V. Gentile, P. Tronville*, Politecnico di Torino, Italy

Vapors from industrial processes such as rubber vulcanization are contaminants. Manufacturers of rubber goods must remove them from the fumes to obey maximum allowable emissions limits set by environmental protection agencies. Other processes, e.g., coffee roasting, release significant amounts of vapors that may have a commercial value into the atmosphere. These contaminants tend to condense in the smoke evacuation systems, implying an economic loss due to maintenance and machinery repositioning. In both cases, it is desirable to capture those vapors effectively, turning them into a resource whenever possible.

Examples of technologies suitable for removing vapors from the air are thermal oxidation, activated carbon adsorption, and wet scrubbers. However, those technologies require frequent maintenance and high operational costs.

We present some experimental results with a prototype built to demonstrate new patented technology to remove vapors from the air. The idea is to force the vapor condensation into tiny droplets and separate them using a high-efficiency cyclone...

Learn More at FILTECH 2023 Conference - Register Now!

Influence of filtration velocity on the local oil distribution of coalescence filter media

C. Straube*, J. Meyer, A. Dittler, Karlsruhe Institute of Technology (KIT), Germany

Fibrous coalescence filters consisting of micro glass fibers and sometimes small amounts of synthetic fibers are widely applied in gas cleaning processes to separate liquid droplets from a gas flow (e.g. oil mists). When separated on the fibers of the filter media, the deposited oil can take different shapes dependent on the oil saturation, wettability, roughness and diameter of the fibers and fiber arrangement (e.g. axisymmetric barrel-shaped droplets, axially asymmetric clam-shell droplets or oil sails between adjacent fibers). To understand the initial state of the coalescence filtration process as well as the impact of the deposited oil structures within the filter matrix on the separation efficiency, it is essential to characterize these deposited oil structures. Using X-Ray microtomography (µ-CT) and an artificial intelligence tool for segmentation, deposited oil structures can be visualized, identified and analyzed down to sizes in the micrometer region. The main emphasis of this work is to quantify and compare oil structures formed at three different filtration velocities at a defined oil saturation of the coalescence filter media by a µ-CT...

Learn More at FILTECH 2023 Conference - Register Now!

Overcoming challenges when measuring particle size distributions in raw and clean gas of oil-injected screw compressors under realistic operating conditions

J. C. Reinelt*; C. Straube; J. Meyer; A. Dittler, Karlsruhe Institute of Technology (KIT); J. Eisengräber-Pabst; T. Grein, MANN+HUMMEL GmbH, Germany

Screw compressors are widely used to provide compressed air for a variety of processes. These compressors are predominantly oil-lubricated and disperse oil as oil mist into the compressed air. This dispersed oil needs to be separated in a following step to minimize oil consumption by recirculating the separated oil and to prevent problems further downstream. Therefore, oil-lubricated screw compressors are equipped with downstream separators, consisting of a centrifugal separator and a coalescence filter. The operating conditions at these coalescers are typically 70 to 100 °C and 5 to 13 bar. The dispersed oil mass that needs to be separated is five to ten times the mass of the compressed air. Unfortunately, most of the published literature characterizing the filter media in terms of differential pressure and filter efficiency is on research at atmospheric pressure, at room temperature, and using concentrations far below the typical values.

This project aimed to close the knowledge gap of oil mist characteristics and filter efficiencies at realistic conditions by making inline measurements of particle size distributions in raw and clean gas of oil-lubricated screw compressors at operating conditions possible...

Learn More at FILTECH 2023 Conference - Register Now!


M02 - Ultrafiltration

Day: 15 February 2023
Time: 13:00 - 14:15 h
Room 4

Session Chair:
Dr. Thomas Peters

Ultrafiltration: The hydrophilicity advantage

S. Dhole, S. Srivastava*, Technorbital Advanced Materials Pvt Ltd, India

Ultrafiltration membrane offer excellent barrier to cryptosporidium, giardia, bacteria and virus and provide a barrier to ensure safe drinking water.

An Ultrafiltration membrane is a thin layer of material that will only allow certain compounds to pass through it. What will pass through the membrane is determined by the size and the chemical characteristics of the membrane and the material being filtered.

A number of different materials are used to prepare membranes for use in water treatment. These materials can be broadly classified as either Organic (polymer membranes) or Inorganic (ceramic membranes). Several types of membranes are used based on the size of contaminants, such as MF for suspended particles (100–1000 nm), UF for bacteria and virus (5–100 nm) and NF for dissolved particles (1–5 nm).

The love for water for a membrane is important point as that helps membrane being cleaned during backwashed without the use of harsh chemicals. The high polarity of POLYNORBIT polymers increases the Hydrophilicity of the nanofiber layer.

PolyNorbit is a copolymer with multiple monomer units to provide different desirable functionalities. It contains several monomer units combined in a molecularly engineered fashion to achieve the needs of high efficiency membranes. This polymer has very high affinity towards water and water transport compared to conventional Polyacrylonitrile, Polysulfone or Polyethersulphone & thus providing excellent transport properties. The polymer is inherently antimicrobial, the high dipole moment of the material interacts with the bacterial cell wall and deactivate the organisms with time. This means one can claim that the membrane is bio-fouling resistant. Though the material is hydrophilic (a property that defines the quality of a UF membrane) in nature, yet it does not dissolve in water. This means that....

Learn More at FILTECH 2023 Conference - Register Now!

Developing hydroxyapatite-based ultrafiltration membrane

E.A. Abdel-Aal*, H.M. Abdel-Ghafar, Central Metallurgical Research and Development Institute (CMRDI), Egypt

Hydroxyapatite (HA) is a natural abundant mineral form of calcium apatite with the chemical formula Ca10(PO4)6(OH)2. The synthetic hydroxyapatite has very wide range of applications in different sectors such as medical, agricultural, biological, chromatography, archeology, and water treatment. The synthesis methods and preparation conditions of hydroxyapatite are studied to prepare HA of high aspect ratio to meet the required specifications for membrane manufacture. HA of ultralong shape was applied for non-flammable papers and air filter membranes. Herein, in this research, ultralong hydroxyapatite crystals are synthesized and utilized for ultrafiltration membranes preparation for water purification...

Learn More at FILTECH 2023 Conference - Register Now!

Sustainable route in the preparation of flat-sheet and hollow fiber polymeric membranes

A. Figoli*, Institute on Membrane Technology, National Research Council of Italy (ITM-CNR), Italy

Membrane technology has been successful in many industrial areas and it can be considered a dominant technology in some of them as in Desalination. Membranes are produced using a wide variety of techniques that mostly depend on the membrane material used and final application. Currently polymeric membranes are produced mostly via phase inversion and using aprotoxic solvents such as N,N Dimethylformamide (DMF), N,N-Dimethylacetamide (DMA) and N-methyl-2-pyrrolidone (NMP) which are toxic and harmful to the environment. The search for new green and more sustainable solvents is, therefore, very attractive and it is also pushed by the REACH restrictions of the European Commission, which banned the use of some of the aprotoxic solvents.

In this research, two case studies are reported, showing an innovative strategy for producing porous membranes in a more sustainable way: a) flat-sheet polyvinylidene difluoride (PVDF) membranes and b) hollow-fiber polyethersulfone (PES) membranes....

Learn More at FILTECH 2023 Conference - Register Now!

F03 / M03

F03 / M03 - Poster

Day: 15 February 2023
Time: 14:45 - 16:00 h
Room 4

Session Chair:
Prof. Dietmar Lerche

Preparation and characterization of meta-aramid wet-laid nonwoven

G.D. Lee*, Y. Kim, J.N. Im, S.J. Doh, Korea Institute of Industrial Technology (KITECH), South Korea

Filters are considered essential for a safe and sustainable environment in modern industries. In typical industrial fields, the use of filters is limited due to the heat emitted along with the pollutants. Therefore, many studies have been conducted on the applicability of heat-resistant materials to filter media. However, since heat-resistant materials are generally thermoset or have high thermal processing temperatures, there are difficulties adopting these to general filter media manufacturing processes consisting of thermal extrusion. In this study, we tried to manufacture meta-aramid nonwovens applicable as a filter media by a wet-laid nonwoven process.

Wet-laid nonwoven samples were manufactured by controlling the proportion of short-cut fiber/fibrid and solid concentration of wet-laid dispersion. And the tendency and deviation of various properties - tensile, tear, basis weight, and thickness - were analyzed comparatively. In addition, a facile method for nonwoven uniformity measurement was suggested and applied since the property is considered as a significant index for filter medium. The results from the new method...

Learn More at FILTECH 2023 Conference - Register Now!

Contribution of sheath-core bicomponent based nonwovens to the design of synthetic composite filter media

R. Winters*, J. Westerdijk, M. Koerntjes, Freudenberg Performance Materials, Netherlands

The design of synthetic air filter media is changing, driven by new standards, new materials and specific customer requirements. Conventional filter packages are becoming a commodity and making space for reengineered solutions, often with demanding specifications and cost structures. Filter media are becoming thinner, cheaper and more efficient, combining additional functionalities and, most importantly, enabling much lower pressure drops. In addition, many experts in the industry are posting difficult safety questions asking about the future of wetlaid and glass-based filters. This trend is feasible in almost all filtration segments from cabin air filtration to HVAC, creating opportunities for high-performance synthetic support layers.

Until recently, conventional layers have almost exclusively provided mechanical support and protected fragile layers of filter either during conversion or end use. They are often based on PP or polyesters suitable for processing in well-known spunbond processes. This study focuses on the unique thermally bonded sheath-core based nonwovens and tailoring these support layers for specific filtration applications. The presentation addresses the effect of polymer choices such as high molecular weight polypropylene (PP), polyesters and co-polyesters (PET and coPET) and – very unusual in the filtration segment – polyamide (PA). The presentation also includes a review of general properties, technological choices and their effect on dimensional stability under various environmental conditions.

Learn More at FILTECH 2023 Conference - Register Now!

On the impact of porous media inhomogeneity on pore scale on reactive flow

O.Iliev, P.Toktaliev*, Fraunhofer Institute for Industrial Mathematics ITWM, Germany

Reactive transport of chemically active species in porous media is a typical phenomenon and key part of the process in catalytic filters, chemical air purification units and drug delivery applications, to name just a few. This is by no means a complete list of areas of application of the reactive flow in a porous media. Usually a set of numerical tools is used to investigate reactive flows at different scales, ranging from whole device scale through mesoscales, where porous media is assumed to be homogeneous, to micro scale, where flow and species transport in primary pores are considered. Porous media inhomogeneity can be directly considered only at a pore scale and in larger scales models it is introduced by the concept of effective diffusion, effective reaction, space-dependent permeability or numerical/experimental correlations. However, both concepts are critically dependent on experimental or numerical results at pore scale. Moreover, the impact of structural inhomogeneity at pore scale, including mean pore size and pore size distribution, on efficiency, being an essential source for potential improvements of overall porous media performance and object to optimization, rarely explored in real geometries [1,2]. Thus, the importance of the direct modeling of porous samples inhomogeneity, as well as of the numerical tools which are able to manage pore scale modeling, can’t be underestimated. In the current work we consider and discuss a few examples of pore scale reactive flows in porous media from different areas – catalytic filters, air purification, drug delivery and requirements imposed by the problems on a numerical tool used to properly model the influence of geometrical inhomogeneity at pore scale on overall process parameters...

Learn More at FILTECH 2023 Conference - Register Now!

AI-supported improvement of quality control and work quality in automotive filter production

C. Boltersdorf*, T. Gries, RWTH Aachen University; Dominik Herper, GKD - Gebr. Kufferath AG, Germany

The WIRKsam joint project is designed to research and test the use of artificial intelligence for work design through the cooperation of scientific institutions and companies in operational practice using demonstrators. The companies involved in the project will be accompanied and supported in the process of change associated with the introduction and use of artificial intelligence.

In work package 5.1, the AI-supported improvement of quality control and work quality in automotive filter production is being researched in the automotive filter production at GKD - Gebr. Kufferath AG.

Filters for the automotive market are critical components with very high quality requirements for production. The technical solutions available to date, such as classic image processing, are not yet able to meet the high demands of quality control. For this reason, manual quality control is also carried out by employees. A very high level of training is required to recognize the fine fabric defects. A high level of concentration, unergonomic working postures and the monotony of the task lead to rapid fatigue of the employee.

Within the framework of WIRKsam, a camera-based defect detection system is to be improved by an integrated AI to such an extent that a shift away from manual quality control is possible...

Learn More at FILTECH 2023 Conference - Register Now!

Fibre characterisation by dynamic image analysis

J. Lunewski*, E. Schmidt, University of Wuppertal, Germany

Filter separators represent a widespread option to remove solid and liquid particles out of gases. A common feature of all filter separators describes the presence of a filter medium. For example, the filter medium can be composed of natural or synthetic fibres. During the manufacturing process, the fibre grinding degree affects the fibre length and pore size distribution of the filter medium. Knowledge of the initial fibre length distribution contributes to the prediction of the operating behaviour of a surface filter.

Dynamic image analysis provides an automated evaluation method to determine the size and shape of particles. However, interlocking fibre bonds within a bulk complicate the characterisation of single fibres. This problem requires a singularisation of the interlocking fibres before the actual measurement starts. Therefore, this paper presents an approach towards the application of dynamic image analysis of fibrous particles...

Learn More at FILTECH 2023 Conference - Register Now!

Membrane characterization by analytical multisample photo-centrifugal filtration (ACF)

P. Lösch, F. Krull*, S. Antonyuk, University of Kaiserslautern-Landau; S. Boldt, D. Krause, D. Lerche, LUM GmbH, Germany

Especially in pharma and biotechnology, the development of new products leads to a need of matching required processes. For example, proteins or vaccines, which are present in suspensions require separation processes for further processing. Due to the low mechanical resilience, filtration with membranes is often used. To cover a wide range of processes, these tests require a large quantity of filtration media and a large amount of the test suspension. For cost reduction in both the use of valuable pharmaceutical products and newly developed filter material, it is advisable to reduce the required material input. A possibility is to perform the filtration experiments by means of analytical photo-centrifugation filtration (ACF) which allows a simple and fast membrane characterization and filterability with high throughput. With ACF it is possible to analyze up to 12 different samples of about 1 ml at the same time. A special developed filtration cell...

Learn More at FILTECH 2023 Conference - Register Now!

Model of steady-state ultrafiltration of colloidal suspension with formation of non-newtonian concentration polarization layer and compressible deposit under laminar cross-flow

M. Loginov*, H. Gholamian, G. Gésan-Guiziou, INRAE - National Institute for Agriculture, Food and Environment, France

A model for description of local filtrate flux and local solids concentration distribution in the filter channel at the steady-state of the cross-flow membrane filtration of colloidal suspension is proposed...

Learn More at FILTECH 2023 Conference - Register Now!


G08 - Poster I

Day: 15 February 2023
Time: 14:45 - 16:00 h
Room 2

Session Chair:
Prof. Gerd Mauschitz

Influence of pulse-jet pressure on the performance of the cartridge type dust collector in clean-on-demand mode

K. Fukui*, K. Furumoto, Y. Muraoka, T. Fukasawa, T. Ishigami, Hiroshima University, Japan; Z. Yu, Northeastern University, China

Continuous operation of a compact dust collector with a pleated filter, which is widely used, requires the removal of collected dust particles accumulated on the filter surface and inside. The pulse-jet cleaning method is commonly used. However, since dust particles cannot be completely removed and some of them remain, the performance of the dust collector, such as pressure drop, effective filtration area etc., changes with operation time. The objective of this study is to investigate the influence of pulse-jet pressure on these performances and to analyze the accumulation behavior of dust particles on and inside the filter...

Learn More at FILTECH 2023 Conference - Register Now!

Moisture and thickness influence in precoating filtration

B.K.S.A. Andrade, R. Sartim, M.L. Aguiar*, Federal University of São Carlos, Brazil

The steel industry is responsible for a large number of pollutants that need to be treated before being released into the atmosphere, such as particulate materials. To clean the particulate materials, the dirty gas passes through a bag filter that is a gas-solid filtration equipment with high collection efficiency for a wide particle size range, low cost and easy operation. A pre-treatment used in the filter bags to increase the collection efficiency is the precoating which aims to reduce or prevent the saturation of the bags. Precoating consists of covering the inside and the surface of non-woven filter media with particulate material forming an initial dust layer that acts as a filtering element with surface filtration as the collection mechanism. In addition to ensuring that the air flow passes freely through the bag, improving the performance of the filter medium while extending its useful life. Precoating is studied in a bag filter to remove particulate matter, however, there are not many studies on precoating in a bag filter in relation to industry, especially steel industry. Observing the deficiency in the literature on the subject, this work aims to evaluate the precoating efficiency in the particulate matter collection in the steel industry...

Learn More at FILTECH 2023 Conference - Register Now!

Efficiency study and characterization of pan nanofibers incorporated with ZnO nanoparticles

E.N. Silva, M.L. Aguiar*, V.G.G. Bettega*, Federal University of São Carlos, Brazil

Particulate matter suspended in the air is a health hazard and it can cause a number of serious respiratory illnesses. In addition, microorganisms such as viruses, bacteria and fungi are also classified as particulate matter, more specifically, bioaerosols, and it can be inhaled by humans causing diseases such as: Influenza, tuberculosis and covid-19. To reatin particulate materials, electrospun filters are used due to their high surface area and good ability to capture airborne particles. In addition, this material allows the incorporation of nanoparticles in its fibers that improve filtration performance, some of which have a biocidal effect. In this context, this work aims at the production of a filter medium produced from dissolved dimethylformamide (DMF) polyacrylonitrile, with zinc oxide nanoparticles incorporated into the solution...

Learn More at FILTECH 2023 Conference - Register Now!

Modeling air filtration on the micron- and submicron-scale using fully-resolved CFD-DEM simulation

J. Wieremiejczuk*, S. Gangani*, C. Mehring, University of Stuttgart, Germany

The ideal depth filter media aims for the highest possible degree of separation, with the lowest possible aerodynamic resistance of the fluid flowing through the medium and maximal particle loading capacity. The overall goal of this study is the development of an efficient filtration submodel, predicting collection efficiency and filter pressure drop of fibrous filter media over time, derived from data generated by detailed fully- resolved simulations at the micron- and submicron-scale for Arizona Dust. In this context, the current work investigates particle deposition on a single fiber collector using three-dimensional, fully resolved simulations based on a coupled Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) approach. In this approach the fluid field around each particle is accurately resolved through an immersed-boundary method and, consequently, the aerodynamic forces acting on each particle are accurately predicted after integrating the surface stresses and pressure along the particle surface. Contacts between two particles or particle and fiber are resolved directly by the DEM algorithm. Vital contact model parameters for the DEM simulation, e.g. coefficient of restitution, rolling- and sliding friction coefficients and adhesion- cohesion parameters, are calibrated upfront using a bulk calibration approach. Here, bulk material properties are measured from suitable experiments and used to calibrate relevant model parameters in virtual-twin simulations of said experiments. Based on the sizes of particles and fibers, the current work is divided into two parts. The first part considers the deposition of micron-sized particles on a micron- sized fiber, whereas the second part simulates the deposition of sub-micron-sized particles on a nanofiber. For the latter effort, slip flow around the fiber and Brownian motion of the particles is included. The presented model allows for an accurate description of the behavior of aerosol particles dispersed...

Learn More at FILTECH 2023 Conference - Register Now!

Generation of datasets using POD for an artificial intelligence to optimize an energy-efficient HVAC system

L. Bittel*, A. Baumann, L. Springsklee, S. Berger, J. Niessner, Heilbronn University of Applied Sciences, Germany

Due to the COVID-19 pandemic, the adjustment of air supply parameters is an important issue in terms of reducing the risk of indoor airborne infection. This is often done without considering energy efficiency or thermal comfort (Srivastava, 2021; Kurnitski, 2021). The risk of infection in existing HVAC systems has already been investigated in the past. There are extensive publications of experimental and simulative studies (Motamedi, 2022; Tobisch, 2021). In addition, recommendations for HVAC have been made using several models (Liu, 2021; Pathak, 2021). However, the studies are related to a specific space or rather to a regulation instead of a prediction and adapted control.

This work aims to predict and control an indoor HVAC system, e.g. in a classroom or in a public transport vehicle, and to adapt it in an energy-efficient and health-oriented manner using an artificial intelligence...

Learn More at FILTECH 2023 Conference - Register Now!

Simulation of filter efficiency and pressure drop using fiber size distribution

M. Wist*, M. Schroers, F. Schmidt, University Duisburg-Essen (UDE); T. Engelke, D. Kasper, E. Däuber, Institute of Energy and Environmental Technology e.V. (IUTA), Germany

Since 2018, air filters for general ventilation have to be classified and the performance parameters pressure drop and fractional efficiency determined in accordance with ISO 16890. The introduction of this guideline also has an impact on regulations that (still) refer to filter classes according to EN 779. For example, there are different recommendations at national (VDI 6022) and international (Eurovent 4/23) levels for the selection of those air filters depending on the outside air quality and type of use of the building in order to achieve the required supply air quality. The achieved supply air qualities and in particular the achieved indoor air quality in practice when using the recommended filter types have not been published yet. These questions are being investigated in a current research project (IGF 21330 N)...

Learn More at FILTECH 2023 Conference - Register Now!

Development of long-term stable filters for air cleaners based on electrically conductive tufted structures

S. Schumacher,*, B. Schunke, C. Asbach, Institute of Energy and Environmental Technology e.V. (IUTA); L. Zobel, D. Hanuschik, B. Aslan, RWTH Aachen University, Germany

In the light of the growing awareness of air pollution and the COVID-19 pandemic, the need for improving the indoor air quality and reducing the transmission of airborne infections is steadily increasing. Air cleaners have a great potential for beneficially contributing to these aims by filtration of airborne particles. So far, most air cleaners utilize electret filters, which combine a high filtration efficiency with a low pressure drop. However, electret filters lose their non-regenerative charge over time, which reduces the filtration efficiency with increasing service life. On the other hand, there are electrostatic precipitators (ESP), which are resource saving as their collection plates can be washed, but the generation of ions by corona discharging is often accompanied by the emission of ozone. The goal of the project PureAir is to develop a filtration solution that combines the high filtration efficiency without ozone production of electret filters with the long-term stability and washability of ESP. The goal shall be achieved with...

Learn More at FILTECH 2023 Conference - Register Now!

Insights into filtration performance of ISO 16890 and ISO 29463 air filter media using DEHS particles classified by aerodynamic diameter

S. Payne, J. Symonds, Cambustion Ltd, UK

Filters used in heating, ventilation and air-conditioning (HVAC) systems are categorised by ISO 16890 depending on the fractional efficiency for aerosol removal during testing measured using an Optical Particle Counter (OPC). ePM1 results are reported for DiEthylHexylSebacate (DEHS) particles with particle diameters of 0.3 µm – 1 µm. Higher efficiency filters (such as those intended for hospitals and clean room environments) are categorised by ISO 29463 based on the most penetrating particle size determined in the range 0.04 µm – 1 µm using monodisperse or polydisperse test aerosols and a Condensation Particle Counter (CPC) to detect the smallest particles. This submicron particle size range is of major public concern due to potential penetration through the respiratory system and negative effects on human health.

An ideal instrument for detailed characterisation of air filter media is the Aerodynamic Aerosol Classifier (AAC), which offers substantially higher particle transmission efficiency than electrical mobility techniques and elimination of multiple charging issues (Payne et al. 2018). The AAC selects truly monodisperse liquid or solid particles without charging from 0.025 µm to >5 µm, by passing aerosol between rotating concentric cylinders with a coaxial sheath flow. In conjunction with a CPC, the AAC can also conduct high resolution scans of polydisperse particle size distributions in aerodynamic space, which is the most relevant metric for aerosol flow through filters and particle capture by interception or impaction.

In this study the filtration properties of commercial air filter media adhering to different categories in ISO standards 16890 and 29463 were evaluated in detail. Polydisperse DEHS particle size distributions up-and downstream of the filter samples were recorded over a broad size range, using a continuous scanning AAC procedure (Payne et al. 2019)....

Learn More at FILTECH 2023 Conference - Register Now!

Innovative solution for eliminating microbes from room air using roll to roll copper coating on non-wovens

P. Goradia*, Exposome Pvt Ltd., India

The air filters fabrics made up of polypropylene plastic were coated with novel anti- microbial electroless plating technology of electroless copper to neutralize bacteria and viruses on contact as the air passes over the mesh. The treated filters were fitted in the air conditioners and air samples from different locations, before and after switching on the device with filters were collected. The microbiological analysis of active air sampling as the air passes over the mesh was done and the total Plate Count (TPC), which detects and quantitates total bacterial concentration in the sample after 24 h of incubation and Yeast and Mold Counts (YMC) used to detect and quantify the amount of fungal growth, was recorded as under. Air samples collected with Sample 1 filters showed...

Learn More at FILTECH 2023 Conference - Register Now!

Antipathogenic filtration media developed using copper oxide nano ink

P. Nekkalapudi, J. Morrissey, D. Devonport, I. Naasani, G.W.V. Cave*, Nanosynth Group, Plc/Nanovate, Ltd, UK

Copper oxide (CuO) nanoparticles functionalised using amino acids, were prepared and formulated into an effective antipathogenic ink. Following successful incorporation of the developed ink into disposable face masks for the prevention of respiratory infections, we demonstrate here the successful development and incorpration of the CuO nanoparticle ink into HVAC filter media. The nano ink was applied and cured on polyester and polypropelyne HVAC filtration material and evaluated for antiviral and antipathogenic performance. At least a 90% reduction was found in influenza and SARSCoV2 viruses after 2 hours treatment and at least 99% reduction was found in Pseudomonas aeruginosa Acinetobacter buamannii and Escherichia coli after 18 hours treatment.

The medicinal properties of copper has been well established and have been used since the time of the Egyptian empire. Current uses of copper include hospital touch surfaces e.g. bed frames and door handles, due to copper oxide having unique electrical properties allowing biomedical and antipathogenic properties. Copper nanoparticles were used during both the Swine flu and Bird flu outbreaks and, more recently, have been used to combat the SARSCoV-19 pandemic. Herein we report an optimised synthesis of copper nanoparticles and their functionalisation of filtration devices, including the antiviral and antimicrobial properties...

Learn More at FILTECH 2023 Conference - Register Now!

Investigation of biological pollutant concentration adding an air purifier to the air filter in HVAC Unit air pollution in university classrooms - Pilot study

G. Porta, G. Micheloni, G. Montalbano, Insubria University; L. Nappa*, V. Guttadauria, OVER, Italy

University and Schools are the most used social infrastructures, the first place for social activity and the most important indoor environment for students besides the home.

The COVID-19 pandemic has demonstrated the need for strategies to control the spread of airborne respiratory pathogens and whether HVAC filtering systems (including maintenance plans) are enough to guarantee good indoor air quality. This has brought an increasing demand for innovating filtering systems for novel technologies to prioritize clean air: Controlling the presence of biological pollutants must take in the countless sources of these pollutants, as the HVAC system itself, the recirculation rate of exhausted air, the continuous emission of microorganism by the occupants and pollutions entrance from outside areas.

The first aim of this paper has been to monitor the bacteria and fungi air concentration air by traditional microbiological techniques like counting the grown cultures on Petri dishes on air treated using microflow instruments and evaluating the efficacy of Crossfield filtering technologies in antimicrobial activity against bacteria, fungi, and viruses where the HVAC system already treats the air in university classroom during lessons.

The main objective of this test campaign will be to investigate the presence of Antibiotic-resistant pathogens in bacteria culture collected during this pilot campaign and their inactivation using Crossfield technology:

Antibiotic-resistant pathogens pose a significant threat to human health. Several dispersal mechanisms have been described, but the transport of microbes and antibiotic-resistance genes via atmospheric particles has received little attention as a pathway for global dissemination.

To reach the goal we will apply culture independent techniques based on next generation sequences to detect microorganisms’ nucleic acid in parallel to traditional microbiological technique.

Learn More at FILTECH 2023 Conference - Register Now!

Development of a practical laboratory testing procedure for mobile dust collection systems with cleanable filters

M. Wist*, F. Schmidt, University Duisburg-Essen (UDE); T. Engelke, Institute of Energy and Environmental Technology e.V. (IUTA), Germany

Due to the flexible applicability and easy handling, mobile dust collection systems with cleanable filters are often used to reduce high particle loads at changing workplaces and to remove particles from the room air. Most mobile dust collectors use the established method of differential pressure-controlled pulse jet filter cleaning to unload and extend the life of the filter cartridges. The performance of dust collection systems depends on many factors: the filter element used, dust and carrier gas properties, operating method, and time. The size and design are primarily based on the extraction volume flow and dust concentration. Dust collectors from different manufacturers thus differ in their collection performance due to their design. The objective is to define a testing procedure to evaluate in advance and compare the performance of dust collection systems with integrated fan and cleanable filters after a long period of usage among different manufacturers. Performance data such as system pressure drop, gas flow rate, system energy consumption, and particulate emission from the system after accelerated aging are to be determined...

Learn More at FILTECH 2023 Conference - Register Now!

Smartgreen – Accounting the ecosystem-performance of urban greenings

M. Kaul*, G. Reznik, E. Schmidt, University of Wuppertal, Germany

Urban Greenings represent high-performance instruments dealing the consequences of the climate change. They provide shade, cool the air by evaporation and ensure the vital gas exchange concerning oxygen, carbon dioxide and nitrogen oxide. After all, the plants separate harmful fine dust as well.

Measuring the overall performance of these greenings is possible comparing the values of the parameters on the luv- and on the lee-side using high-performance measuring devices. Due to the dependence on the wind direction those investigations are very time- and cost-consuming.

The project´s core is therefore the development of a fully-automatic system using a higher number of low-cost sensors for fine dust, gaseous components and temperature. Combined with meteorological measurements like wind-speed and

-direction and communication via Long Range Wide Area Network (LoRaWAN) the system enables the identification of the relevant pair of sensors balancing the performance of urban greenings...

Learn More at FILTECH 2023 Conference - Register Now!

On-line measurements of ultralow concentrated hydrocarbons in compressed air using a photoacoustic detector

H. Bettermann*, T. Dietzel, V. Chmiel, Heinrich-Heine-University Düsseldorf; M. Wittmar, Institute of Energy and Environmental Technology e.V. (IUTA), Germany

This contribution presents a new on-line method for measuring trace gas concentrations for pursuing gas emissions which are released from filters.

The method based primarily on the photoacoustic (PA-) effect. In the underlying PA-effect light is first absorbed by molecules and the absorbed energy is then converted into sound via intermolecular energy transfer processes. The generated sound can then easily be detected by a microphone. The experimental setup only needs a pulsed light source, a sound detector and a measuring cell as basic components. For measuring traces of hydrocarbons the setup was...

Learn More at FILTECH 2023 Conference - Register Now!


G09 - Poster II

Day: 15 February 2023
Time: 14:45 - 16:00 h
Room 3

Session Chair:
Prof. Gernot Krammer

Particle filtering face masks: Investigation of aerosol deposition under real-life wearing conditions

D. Stoll*, M. Kerner, S. Antonyuk, University of Kaiserslautern-Landau, Germany

Particle filtering face masks are designed to protect against (droplet) infection with COVID-19. The viruses that settle in the respiratory tract of an infected person become airborne through fine infectious droplets when sneezing, coughing or speaking, but also when breathing itself, and can thus be inhaled by other people.

The use of conventional microfiber filter media for face masks would be limiting in terms of the filtration performance and protective effect. Due to the mechanical filtration mechanisms, such filter media typically have a filtration minimum for particles in the range around 0.3 μm (Most Penetrating Particle Size), which is also where the infectious droplets and viruses are. This filtration minimum can be compensated by electrostatic fiber charging. Face masks made of such electret filters can be used to filter both infectious droplets and viruses. Consequently, the spread of aerosolized viruses can be contained by wearing face masks.

Unfortunately, research to date has not provided any reliable findings on the influences of real-life wearing conditions, such as wetting of the filter media by droplets from the breathing air and mechanical deformation under alternating flow directions (inhalation and exhalation) on the flow/breathing resistance of the face masks. Local airflow dynamics through the filter media and leaky zones in the contact of the face masks with the face are are also poorly studied. Thus, there is a possibility of becoming infected with the SARS-CoV-2 virus despite wearing a tested face mask. To minimize or eliminate the infection risk, masks have been studied with the aim of optimization.

Crucial is here the transfer of real-life wearing conditions into lab studies. For this purpose, wearing was mimicked using a Sheffield test head with a face mask on. A microtomography (µCT) was used to scan the 3D fir in detail. The resulting scans are shown...

Learn More at FILTECH 2023 Conference - Register Now!

Studies on indoor air filtration supported by simulations

T. Engelke, U. Sager*, S. Haep, Institut für Energie- und Umwelttechnik e. V., Germany

Today, cabin air filters are part of the basic equipment of passenger cars. In addition to the highest possible filtration efficiency for particles and, in the case of combination filters with an activated carbon layer, for harmful gases, the filters must also have a low pressure drop. Another requirement is that the filters fit into the limited installation volume, which usually has a small installation cross-section. Automotive cabin air filters are offered as pleated filters to increase the filter media surface and thus reduce the effective face velocity, resulting in a lower pressure drop.

In the project "Test method for characterizing multi-effect filters for indoor air as a basis for realistic performance assessment", one aspect investigated was the extent to which the relationships between filter media structure (fiber layers and incorporated sorbents), filter geometry (number and depth of pleats), pressure drop and separation efficiency for particles and gaseous contaminants can be described with the aid of CFD simulations.

For this purpose, the pressure differences were determined as experimental tests on both prefabricated automotive cabin filters and the filter media used in them. In addition, tests were carried out to determine the particle fractional collection efficiency as well as breakthrough tests to determine the adsorption capacity. The results were...

Learn More at FILTECH 2023 Conference - Register Now!

Electrospinning nanofiber for efficient cabin air filter applications

F. Tezcan*, V. Demirel, Hifyber - Acik Kart Bilgi Teknolojileri, Turkey

Cabin air filters are part of standard equipment in modern vehicles and protect users in a car cabin from exposure to a variety of contaminants. The presence of fine dust particles in air can cause serious adverse health problems on passengers in car. Despite the various advantages of micro-sized fibrous air filters in the automobile cabin today, more functional improvements are required because they cannot capture ultra-fine dust particles. In order to solve these problems, this study have developed automobile cabin air filter media with nano-sized fibers using nanotechnology.

"Nano" technically refers to physical quantities within the scale of a billionth of the reference unit and nanofibers are the fibers with diameters in the nanometer range. Nanofibers are produced in the form of spider web like structures [1]. Because of easy usage and ability to fabricate nanofibers, electrospinning is one of the most commonly used method [2]. Nanofiber media have low weight, high air permeability and small pore size that make them suitable for various filtration applications, particularly for smaller particles [3-4].

Nanofiber webs formed by nanofibers are able to capture very small particles with their small pores and provide low pressure drop due to their high porosity. By adjusting the amount of nanofiber on the filtration material, the target particles in smaller size can be kept at the desired fractional efficiency levels and the air can be cleaned at the desired rate.

In this study cabin air nanofiber filter media for automotive compared to conventional filter media has been designed to offer the highest protection against fine particles and microorganisms, optimizing the pressure drop and the efficiency of the filter. The capabilities of nanofibers will be explored cabin air filter media performance data. Scanning electron microscope (SEM) and Porometer were used for fiber characterization, and finally, efficiency test were conducted to evaluate the filter performance of developed nanofiber based and traditioanal spunbond air filter. The results showed that...

Learn More at FILTECH 2023 Conference - Register Now!

Wet-laid nonwoven of activated carbon fiber for air filtration

Y. Kim*, G.D. Lee, S.J. Doh, J.N. Im, Korea Institute of Industrial Technology (KITECH), South Korea

Gas adsorption layers for air filtration were fabricated by wet-laid nonwoven process using activated carbon fibers. Considering the wetting effect of ACF during the wet-laid process, the optimal content of ACF was 0.2g/100cm2. The gas removal capacity was not hindered by the blending of the PET binders. The tensile strength, stiffness, and the dimensional stability of the ACF nonwoven could be adjusted by the amount and composition of the binders. With the increase of low-melting PET binder, the mechanical strength was improved but shrinkage during the bonding procedure increased.

The effect of binders on the particulate filtration performances were also evaluated. Binder content and blend ratio had an effect on PFE and air flow resistance, respectively. The ACF nonwoven showed...

Learn More at FILTECH 2023 Conference - Register Now!

Analysis of the dynamic characteristics of the vortex core in the cyclone separator

K. Xie*, J. Wang, J. Wang, G. Sun, China University of Petroleum, China

The cyclone separator is an essential mechanical gas-solid separation equipment, widely used in the pharmaceutical, metallurgical and petrochemical industries. Vortex plays a significant role in the cyclone fluid motion but an insufficient understanding of this underpinning operating mechanism has plagued the performance and expansion of the cyclone technology, leaving the device penchant for several reliability challenges. This study thus aims to numerically investigate the dynamic characteristics and periodic motion of vortex core in the cyclone...

Learn More at FILTECH 2023 Conference - Register Now!

CFD study of the flow field in a stairmands reversed flow cyclone

J. Oranje*, John Crane Indufil, Netherlands

A cyclone is a common piece of equipment that has been used in industry since the 1800s to separate pollutants from gas streams. Although the geometry is simple, the flow in a cyclone is complex, due to the highly turbulent transient three-dimensional nature of the flow. It can therefore be challenging to achieve an accurate estimation of the pressure and velocity field using computational fluid dynamics (CFD). Besides the influence of the geometry and turbulence model, the selected numerical interpolation schemes affect the results of the CFD simulation. The aim of this paper is to provide an overview of the influence of the various numerical interpolation schemes available in Ansys Fluent 2021 R1 on the calculated pressure and velocity field in a Stairmand High-Efficiency cyclone. The CFD results are compared with experimental data obtained by Hoekstra using laser Doppler anemometry (LDA).

Ansys Fluent offers multiple pressure interpolation techniques, where the PRESTO! and body force weighted (BFW) are recommended by Ansys for (axisymmetric) swirling flows. These two pressure interpolation schemes are varied with the available spatial interpolation schemes, including higher-order interpolation schemes for the Reynolds stress term. The interpolation schemes available are first-order upwind (FOU), second-order upwind (SOU), QUICK, and MUSCL, where the latter three are higher-order schemes.

The BFW pressure interpolation scheme significantly underestimates the pressure loss in the cyclone. This deviation in pressure loss can be reduced by using a higher-order interpolation scheme for the Reynolds stress term. However, the deviation is higher than the experimental error for all combinations using the BFW interpolation scheme. For the PRESTO! pressure interpolation scheme, the difference in pressure loss falls within...

Learn More at FILTECH 2023 Conference - Register Now!

Design methodology of a pilot-scale scrubber implemented in a full-scale waste incineration plant for collection of nano and sub-micrometer sized particles in flue gas

A. Hoyos*, A. Joubert, A. Bouhanguel, L. Le Coq, IMT Atlantique; M. Henry, S. Durécu, Séché Environnement, France

Due to their potential and remarkable promises, nanomaterial’s market has considerably increased during the last two decades and it is expected to grow even more in the coming years. This leads to the presence of engineered nanoparticles (ENP) in waste discharges. To date, there is no global strategy for handling waste containing ENP (called nano-waste), therefore it is treated with no specific standard. Thermal treatment is usually preferred as management strategy for nano-waste, although recent studies have shown that, when incinerated, part of its ENP can be released as an aerosol into the flue gas [1-2]. A combination of flue gas cleaning systems is used in Waste Incineration Plants (WIP) to reduce the release of pollutants into the environment. Electrostatic precipitators (ESP) and bag filters are typically used for fine particle removal, while wet scrubbers are employed for acid gases cleaning. Depending on the operating and design conditions, interesting particle collection efficiencies can be achieved by spray scrubbers [3]. Nevertheless, there are only few studies on the performance of downsized [4] or full-scale [5] scrubbers for nanoparticle removal. As regulatory frameworks on particulate emissions intensify, bridging the knowledge gap on nanoparticle collection by wet scrubbers in WIP becomes of great importance. The aim of this study is to present an original methodology to consider, based on numerical particle collection efficiency, for the design of a pilot-scale scrubber intended to be operated on-site of a WIP and fed with the real fumes, with an attempt to evaluate wet scrubber performance in collecting flue gas nanoparticles...

Learn More at FILTECH 2023 Conference - Register Now!

Simultaneous release and separation of dust by means of electrostatically assisted spray nozzle systems - experimental procedures

M. Weidemann*, E. Schmidt, University of Wuppertal, Germany

The use of various raw materials in the form of bulk materials takes place in the building materials industry, agriculture and the food industry, among others. Bulk material handling, transport and storage result in the particle emissions, referred to as dusting.

The aim of the project is to demonstrate the effectiveness of the dust reduction measure "use of spray nozzles" in combination with the effect of electrostatic charging. The special feature here is that the investigations are oriented to the type of stress and the material and thus take into account the character of the dust emissions in a macroscopic scale. Different test set-ups are used to realistically illustrate the bulk handling operations during which dust is released. The effectiveness of the reduction measure is investigated using different operating parameters for dust emission as well as separation. The subsequent electrostatic charging of the spray mist allows the use of water and compressed air to be reduced. An evaluation method for spray nozzle systems is being developed, which considers the economics of the used resources and the material-related efficiency of the dust reduction, with a focus on the fine particle fractions PM2.5 and PM1...

Learn More at FILTECH 2023 Conference - Register Now!

Dust emission predection – Announcing a reference material

N. Woschny*, E. Schmidt, University of Wuppertal, Germany

In bulk material handling, the identification of the possible released dust is crucial. This form of particle emission can cause explosive atmospheres, induce long-term sicknesses or lead to environmental pollution. The identification of the particle mechanisms can help to understand the release process and opens the possibility to invent reliable prediction methods. The release of particles as emissions when handling a bulk solid contains complex mechanisms. It depends on various parameters which can be grouped in environmental aspects, process conditions and in material properties. The use of model bodies for experiments or simulations representing a bulk material in order to identify these mechanisms can be a tool of simplification. Already in several applications, a reference material is considered for the first and further attempts [1–3] when developing and improving simulation models.

The paper deals with the advantages of a reference material using it for investigations in development and improvement of model functions. Further, the challenges using a reference material are outlined. After analysing the named theoretical aspects, the selection process of the components of the material is introduced. Next to this, the manufacturing process is considered here as well...

Learn More at FILTECH 2023 Conference - Register Now!

Single bulk particle investigations for dust release simulations – Describing im-pact and fluid stressing

N. Woschny*, G. Reznik, M. Kaul, E. Schmidt, University of Wuppertal; D. Schulz, H. Kruggel-Emden, Technical University Berlin, Germany

In order to improve models for simulating processes including dust release, single bulk particle investigations were carried out. These investigations focus on the loading scenario “impact” and “fluid stressing”, which both can cause the release of dust particles.

The reason to deal with dust emissions resulting from the handling of bulk solids in production processes is that they can lead to environmental pollution, long-term diseases or cause explosive atmospheres. To reduce these hazards for humans and the environment, prediction methods determining the released dust mass during a process have to be developed. In order to improve dust release simulations a project collaboration between the Institute of Particle Technology (University of Wuppertal) and the Chair of Mechanical Process Engineering and Solids Processing (Technische Universität Berlin) focuses on the development of these methods. The investigations are carried out experimentally and numerically...

Learn More at FILTECH 2023 Conference - Register Now!

Investigations into a jet-based process of direct mixed aggregation in the gas phase for the formation of hetero-aggregates

J. Witte*, E. Schmidt, University of Wuppertal; V. Kolck, H. Kruggel-Emden, Technical University Berlin, Germany

By mixing heterogeneous particle systems, materially different particles can come into direct contact with each other (hetero-contacts), so that new special properties can arise through the resulting interface or in the contact between the different components. The resulting particle systems are also called hetero-aggregates. The overall objective of this research project is to contribute to the development of new particulate products based on hetero-aggregates formed in the gas phase. To achieve this goal, a jet-based process of direct mixed aggregation in the gas phase is to be generated, which enables the controlled formation of hetero-aggregates in suitable quantity and quality...

Learn More at FILTECH 2023 Conference - Register Now!

Removal of nanoparticles by electrostatic precipitation: evaluation of the collection efficiency behavior with the electric field and air velocity

F. de Aquino Lima, G. B. Medeiros*, M. L. Aguiar, V. G. Guerra, Federal University of São Carlos, Brazil

The development and optimization of equipment aimed at removing nanoparticles from atmospheric air has been gaining importance in the current scenario. The adverse effects of these ultrafine particles on human health and the environment motivate the development of techniques for their removal, both for the processes’ sustainability and the mitigation of pollutants. Among the commonly used equipment, electrostatic precipitators stand out for their versatility and, for certain configurations, efficiencies are up to 99.9% in a wide size range.

The present study aims to evaluate the influence of the electric field and spacing between wires in the collection of polydispersed NaCl nanoparticles...

Learn More at FILTECH 2023 Conference - Register Now!

Converting waste expanded polystyrene into filter media by electrospinning technique: Evaluation of air nanofiltration and permeability

F. de Aquino Lima, G.B. Medeiros*, M.L. Aguiar, V.G. Guerra, Federal University of São Carlos, Brazil

Electrospinning is a promising method for the production of filter media for air treatment. This technique allows to obtain fibers in a nanoscale in a simple way and with different morphologies. Aligning this with the possibility of recycling waste increases the potential contribution to the environment and society. Among materials, expanded polystyrene (EPS) represents a major global problem due to its inadequate disposition and difficulty recycling. However, producing fibers by reusing materials is a challenge due to the difficulty of keeping the fibers’ properties constant. In addition, large-scale production should be economically viable, leading to the need for research in order to produce resistant filters, with high filtration efficiency and low pressure drops. Thus, the present work aims at the development of nanometric fibers with good efficiency, low pressure drops and high resistance, from EPS...

Learn More at FILTECH 2023 Conference - Register Now!


L08 - Poster

Day: 15 February 2023
Time: 14:45 - 16:00 h
Room 1

Session Chair:
Prof. Ioannis Nicolaou

Influence of gas injection on the particle separation behavior of a hydrocyclone

T. Senfter, S. Holzer*, D. Hohenwarter, M. Dür, T. Kofler, C. Mayerl, M. Berger, M. Pillei, MCI - The Entrepreneurial School, Austria

The separation of solid-liquid mixtures is an essential process step in many technical applications. For this purpose, a hydrocyclone is often used, which is convincing among other separation techniques due to its robust design and comparatively low maintenance requirements. However, the separation behavior is strongly influenced by the existing feed volume flow. In many cases, the feed depends on the upstream process, resulting in deviations from the nominal volume flow for which the hydrocyclone was designed. These fluctuations in the feed have an effect on the flow field in the separator and, due to the reduced inlet velocity, a decrease in the centrifugal forces acting on the particle. As a consequence, this leads to a decline in separation performance.

For compensation of fluctuating feed volume flow rate, the injection of air into the separation system is investigated. For this purpose, an existing hydrocyclone with a nominal diameter of 80 mm was adapted to be capable of injecting air at the inlet and at the underflow. The separator is fed with particles of the type Carolith 0-0.2 and operated with varying volumetric flow rates in the order of 2-3 m³/h. The effects of the injected amount of air as well as the inlet pressure on the separation efficiency is investigated. Furthermore, a qualitative observation of the air core is carried out.

From the test series, an improved separation performance results for...

Learn More at FILTECH 2023 Conference - Register Now!

Simulation of the separation behavior in solid bowl centrifuges using material functions

H. Baust*, M. Gleiß, H. Nirschl, Karlsruhe Institute of Technology (KIT), Germany

Sustainable and efficient use of resources and equipment while ensuring high product quality is the challenge for the process industry in this century. In this regard, solid-liquid separation is an essential part of many process chains concerning the handling of slurries. For the separation of finest solid particles from liquids, centrifuges such as decanter centrifuges or disc stack separators are commonly used on an industrial scale. The separators operate continuously and can convert high throughputs with short process times. The design of these apparatuses is based on simplified black box models for the stationary state. However, the physical behaviour of the separation process as well as sediment formation and its transport remain unconsidered in this approach. For the selection of a suitable apparatus as well as the optimum adjustment of the operating parameters, a large number of experiments on a pilot scale are necessary. However, changes in the material properties of the initial suspension can lead to a significantly different process behaviour, so that different running parameters are required for an optimal operation of the apparatus.

One challenge is that the process takes place on different time and length scales: The characterization of the disperse phase takes place at the smallest scale. Solids phase characteristics influence the separation-related material functions such as sedimentation, consolidation and sediment transport. In combination with the adjustable operating parameters, the material characteristics define residence time behaviour and flow conditions. Advancing digitalization can make an important contribution to a sustainable development under consideration of all scales. To improve the process understanding...

Learn More at FILTECH 2023 Conference - Register Now!

Experimental analysis of the vibration patterns of disk stack centrifuges for the determination of separation process parameters

N. Janssen*, F.K. Freese, U. Janoske, University of Wuppertal, Germany

The wide range of applications for disk stack centrifuges across industries, from food industry, like beer or dairy production to the pharmaceutical industry or the purification of engine oil, offers great potential for reducing the energy consumption of industrial processes. Intelligent centrifuges that adapt themselves to changing process conditions can optimally adjust energy consumption and/or separation performance. Conventional centrifuges, therefore, in most cases do not operate in optimum conditions. Increased downtimes, high consumption of detergents, and frequent restarts of the centrifuges are the result. The reasons are the complex product properties, such as viscosity, density, or solid content, as well as the locally and time varying deposition of particles in the centrifuge, that cannot be measured in real-time in industrial environments. Suitable measurement equipment is very expensive or not available.

In this work, a novel method to represent the current state of the separation process using specific vibration patterns of the machine is shown...

Learn More at FILTECH 2023 Conference - Register Now!

Experimental study of flocculation and flotation for the treatment of drilling wastewater

X. Ma*, J.-Y. Chen, H. Chi, Z. Zhang, Z. Zhang, China University of Petroleum, China

The treatment effect of drilling wastewater by flocculation and flotation is studied through experiments. The effects of residence time and bubble generator on COD and SS removal are investigated, focusing on the efficiency curve. The results show that the COD removal efficiency of drilling wastewater can be stabilized at about 90% and the SS removal efficiency at about...

Learn More at FILTECH 2023 Conference - Register Now!

Development of a modular process chain for the selective recovery of technology metals

T. Dobler*, M. Gleiß, H. Nirschl, Karlsruhe Institute of Technology (KIT), Germany

Cell phones, laptops or solar cells are becoming more and more important in the last decades and it is hard to imagine today's life without them. Crucial components of such electronic devices are, among others, rare earths and the limited occurring technology metals gallium and indium. To meet their demand in the coming years, recycling processes, especially those that enable selective recovery of the individual components, are steadily gaining in significance.

One possible process chain for the selective reclaiming of technology metals is two-phase flotation followed by mechanical and thermal treatment. For this purpose, solidified metal slag is first crushed by a laboratory ball mill and then separated into its individual components in a continuously operated flotation tank. In contrast to the already established froth flotation, the particles remain in a liquid phase and can subsequently be washed and dehumidified on a laboratory belt filter. Finally, the dried pure substance is removed from the filter.

The design as well as the apparatus implementation of the modular process chain will be discussed. Furthermore, experimental results will be shown...

Learn More at FILTECH 2023 Conference - Register Now!

Regenerative capability of membranes in case of fouling caused by microalgae

V. Bächle*, M. Gleiß, H. Nirschl, Karlsruhe Institute of Technology (KIT), Germany

Microalgae shows great research potential as they are an efficient supplier of important proteins, unsaturated fatty acids, oils, colourants and vitamins. Therefore, they have a wide range of applications and are interesting raw materials in the food-, chemical-, bioindustry and pharmaceutical sectors. In addition, oils and cell residues can be used as energy sources after cell contents have been harvested. At the moment, these advantages are only countered by the high costs of harvesting. These arise from the compression tendency of the cells during filtration, which results in a correspondingly high cake resistance. For an economical mass flow, the algae are currently filtrated via a centrifuge. However, the entire suspension must be accelerated, which in the case of algae with a maximum dry biomass content of 2 g/L consists largely of water. Here, the vacuum drum filter with thin film filtration and cake heights smaller than 2 mm provides an efficient alternative. The low cake heights keep the cake resistance low and thus guarantee a flux through the filter medium. Membranes are used as filter media because they have a flat surface that allows the filter cake to be removed without leaving any residue particles and the filtrate can be taken out directly. A roller is used for cake discharge, which removes the cake from the drum by shearing and adhesive forces. However, the shearing on the filter cake and the membrane surface causes biofouling, which considerably reduces the mass flow through the membrane after a few filtration cycles.

In the context of this study, different cleaning methods are applied to the membrane and the regeneration behaviour is validated via the solid mass flow. Fouling takes place via microalgae, which were previously deep frozen and defrosted. The intracellular polymeric fluids that emerge as a result have a greater tendency to fouling, which means that the cleaning effect is more pronounced. This change in the filtrated mass after the various cleaning processes will be presented and discussed....

Learn More at FILTECH 2023 Conference - Register Now!

Optimal control of parallel pressure filtration systems

H. Aalto*, Take Control Oy, Finland

Pressure filtration, or cake filtration, is commonly used in chemical and biochemical industries as well as in the mining industry. Automatic control of multiple parallel filters simultaneously in order to increase total throughput is known to be challenging (Bähner 2019). Typically, a process unit has some processing steps upstream the PFS including some buffer tank volume, which can be utilized for optimized throughput control (Aske and Skogestad, 2009).

It is a common practice to try to keep a constant volumetric flow rate through the individual filters during their running cycle for all filters in a PFS, which makes it optimal to maximize the run cycle until the differential pressure (DP) over the filter reaches a suitable value, approaching maximum allowed DP. However, in practice, the individual filters often show a non-constant flow rate behavior being rather a decreasing function of time. Using the DP dependence on flow rate and filter parameters like filter area and cake resistance offered by the conventional pressure filtration theory, it can be mathematically verified, that it is more optimal to have a decreasing filter flow rate Q(t), if it is desired to maximize the average throughput...

....Starting a filter with a high flow rate and let it decrease towards the end of the run cycle is optimal from the point of view of maximal average throughput. It is not recommended to let Q(t) increase at later times during the run cycle, a constraint that can be included in material balance control. Q(t) is to high degree determined by the material balance control of the whole unit, but assuming Q(t) is a decreasing function, there exists an optimum Tr*, which , again can be demonstrated mathematically and further maximizes the average throughput.

The full paper will treat the optimization formulations above in detail, and elaborate on three different material balance control options for a process unit where a PFS with multiple filters is included. A dynamic simulation model for a process unit with three buffer tanks followed by a PFS with 5 parallel filters will be discussed and simulation results for different scenarios will be provided. The results show...

Learn More at FILTECH 2023 Conference - Register Now!

Ore residue filtration: cake post-dewatering by pressurized air

B. Fränkle*, H. Nirschl, Karlsruhe Institute of Technology (KIT), Germany, J. Chaponnel, FLSmidth Salt Lake City Operations, USA

In the mining industry, large process streams have to be handled, using different process engineering systems and processes. In addition to the crushing of the ore down to the micrometer range and successful separation of the valuable material, the dewatering of the residues is important. In order to minimize the dangerous storage of these in settling ponds secured with dams and to increase the economic efficiency by a process water recovery additionally, a filtration is carried out after thickening. Recessed plate filter presses are suitable for this purpose, as they ensure effective dewatering due to the high effective pressure level. In order to obtain a sufficiently low residual moisture ensuring geotechnical stability suitable for stacking within a very short time, gas differential pressure dewatering is often applied after filtration.

Determination of post-dewatering properties of ore processing residues from a copper mine on a laboratory filter press by examination of residual moisture is the aim of this study....

Learn More at FILTECH 2023 Conference - Register Now!

A Holistic approach of the filtration-drying process

V. Spies, BHS-Sonthofen GmbH, Germany

In the chemical industry, many solid products need to be obtained from a slurry. The separation of the solid and liquid phases is usually carried out in two steps: mechanical solid-liquid separation, e.g., by means of filtration, followed by a thermal drying process, e.g., by means of vacuum drying. The traditional way of work is to observe each process steps as unit operation with pre-defined targets. However, if we make a holistic observation of the complete process, it is interesting to know how to combine these two process steps in order to minimize the total energy consumption. By comparing the energy consumption vs. remaining moisture curves obtained in lab-scale experiments it is possible to predict the optimal point to switch from mechanical to thermal drying process.

In a suspension with low solid concentration, whereas the interaction between the solid particles is negligible, mechanical solid-liquid separation is usually very energy efficient. As the solid concentration increases and the suspension becomes gradually a packing of the particles, the interaction between the neighboring particles becomes more and more relevant. In particular, in a wet packing the system is dominated by the capillary force. The efficiency of mechanical separation drops rapidly with the decrease of the solvent residue in the packing.

The thermal drying process is based on the thermodynamic equilibrium of the solvent molecules between the liquid and the gas phases. The thermal drying process is related to high-energy consumption – to heat up the product and to provide sufficient energy for evaporation. It is possible to remove...

Learn More at FILTECH 2023 Conference - Register Now!


G10 - Pulse-Jet Cleaned Filters

Day: 15 February 2023
Time: 16:45 - 18:00 h
Room 3

Session Chair:
Prof. Monica Lopes Aguiar

On the trade-off between energy efficiency and particle emissions for pulse-jet cleaned filters

P. Bächler*, J. Meyer, A. Dittler, Karlsruhe Institute of Technology (KIT), Germany

Pulse-jet cleaned filters are commonly used for the separation of particles from dust-laden gas streams for the purpose of product recovery or environmental protection. While past research focused on e.g. minimizing dust emissions, energy aspects are gaining relevance in the context of rising energy-costs and tackling climate change.

While the differential pressure between the raw-gas side and the clean-gas side of the filter is one major indication for the energy demand, the required consumption of pressurized air for the jet-pulse also has to be considered in a total energy balance. Filter operation allows for a variety of parameters (e.g. cleaning frequency, tank pressure for filter regeneration, valve opening time, etc.) to be adjusted that have an impact on energy demand and dust emissions. While frequent cleaning of the filters creates a low differential pressure level, the consumption of pressurized air may become considerable. Additionally, particle penetration is predominantly possible only after cake detachment so that emissions presumably increase for shorter cycle times. Höflinger et al. proposed a method for the evaluation of filter media under energy considerations for filter test rigs, taking into account the contribution of differential pressure as well as pressurized air that can be transferred to actual filter operation in order to evaluate filter performance regarding energy aspects.

In this study, the operation behavior of a pilot-scale baghouse filter with a total of nine filter bags (needle-felt filter medium) was analyzed regarding energy consumption and particle emissions...

Learn More at FILTECH 2023 Conference - Register Now!

Comparative analysis of filtration performance between flat based and industrial pilot pulse-jet test rigs using polyester filter materials

A.K. Choudhary*, National Institute of Technology Jalandhar; S. Dutta, Bannari Amman Institute of Technology, India

Fabric dust collectors work by drawing dust laden gas through a semi-permeable fabric which is usually constructed in the form of tubular sleeves, longitudinal envelopes or pleated elements. As the gas passes through the fabric, the particles in the gas stream are retained, leading to the formation of a layer of dust on the surface. This is normally referred to as a ‘dust cake’. After a period of time, the accumulated dust leads to a reduction in the permeability of the material, and creates an increased pressure drop. Consequently, the fabric must be cleaned at appropriate intervals to return the pressure drop to a more acceptable level. Dust is then again collected and the filter continues through cycles of dust accumulation and cleaning. Earlier the work carried out by Mukhopadhyay and Chaudhary the following conclusion is drawn: All the pressure parameters (peak pressure, residual pressure and cake pressure) decrease with an increase in cleaning pulse pressure (higher cleaning intensity) and fibre denier in the media. Furthermore, at any level of pulse pressure and fibre fineness, all the aforesaid pressure parameters increase significantly from the unsteady state to the steady stage of operation. Interaction effects among pulse pressure and fibre denier in filter media becomes very large with the passage of filtration time. This implies that the role of dust-fabric interaction on various pressure differentials becomes prominent at the steady state of filtration operation. At steady state, pulse pressure can be set at a lower level for media made up of coarser fibre and vice versa. This will result in...

Learn More at FILTECH 2023 Conference - Register Now!

The potential of Computational Fluid Dynamics (CFD) for efficient pulse-jet cleaning of fabric filters

G.V. Messa*, Politecnico di Milano; C. Maggi, L. Montanelli, CleanAir Europe S.r.l., Italy

Pulse jet is a well-established technique for cleaning of fabric filters, which consists in exploiting the mechanical (shaking) action of a pressure wave produced by a compressed air jet and travelling across the bag filter to remove the dust cake from its surface. Considerable attention has been devoted to making the process more efficient and cost-effective, resulting in a collection of best practices and guidelines obtained from the professional experience of practitioners, often complemented by experimental testing on pilot plants at the laboratory scale. Here a different approach is adopted, namely, the computer simulation of the air flow through Computational Fluid Dynamics (CFD) techniques. Thanks to the constant increase in computer power and capability of simulation software, CFD is now used in any engineering area involving fluid flows. Key advantages of CFD compared to the more traditional laboratory testing are the large amount of distributed information that a computer simulation can provide, the (relatively) low economic cost, as well as the (virtual) possibility to simulate any type of flow process regardless of its complexity and geometrical scale. However, from the point of view of the user, the main drawback is the high computational burden of the simulation, intended as the combination of calculation time and memory requirements. In almost all cases of engineering relevance, such as for instance those involving turbulent flows, the fluid flow equations obtained from the basic physical principles, i.e. mass, momentum, and energy conservation, must be first mathematically manipulated and then numerically approximated to be handled by a computer. This produces a number of coefficients, parameters, and closure equations which are, in the end, not well characterized and empirical in nature. These must be decided by the user, thus, creating uncertainty and possible lack of confidence in the simulation results. So, the real challenge of CFD users is not only (and not so much) to solve the equations but, rather, to ensure that the combination of settings (sub-models, parameters etc.) allows for reliable numerical predictions.

The present contribution aims at disclosing the potential of CFD in the application to pulse jet cleaning of fabric filters. Indeed, some studies have been already published in which CFD was used to simulate the process; however, most of them are either pioneering explorations (e.g., Laux et al., 1993) or recent investigations shedding some light on the functioning of the entire cleaning line (e.g., Anderson et al., 2016). Conversely, the scope of the current work is to assess the actual capability of CFD as an effective engineering tool, satisfying the requirements of accuracy, robustness, and computational performance...

Learn More at FILTECH 2023 Conference - Register Now!


G11 - Modelling and Simulation

Day: 15 February 2023
Time: 16:45 - 18:00 h
Room 4

Session Chair:
Prof. Dominique Thomas

CFD modelling tool for multiple filter systems on the macro level

U. Heck*, M. Becker, DHCAE Tools GmbH, Germany

In many systems, multiple filter elements are used to increase the filter area. Typical examples are dust filter plants with hundreds of single filter bags or cartridge filter plants with several filter elements. The crucial factor for an efficient use of the installed filter area is a uniform loading of the filter area. However, this cannot always be achieved on the upstream side, especially if the filter system has to be individually adapted to the constructional conditions. If the filters are not loaded evenly, this can easily lead to increased operating costs due to high pressure loss, frequent cleaning, damage to the filters and thus shorter service lifetimes of the filter system.

The contribution presents a simulation tool based on flow simulations (CFD) for filtration plants. The simulation tool is based on the open-source CFD toolbox OpenFOAM. In the modelling approach an Euler-Lagrangian formulation for particle transport and a porous media representation for the filters are used. The interactions of local loading on the filter segment, the local resistance increase due to particle deposition and the resulting shift of the continuous flow are considered in an iterative approach.

This modelling approach has been extensively extended with regard to multiple filter systems in order to represent these systems efficiently....

Learn More at FILTECH 2023 Conference - Register Now!

Structural changes in the filtering layer during the dust separation with filtering separators — A holistic view of the filtration process

Q. Zhang*, University of Wuppertal, Germany

A new, clean filter medium for surface filtration always starts with the initial phase in which the dust separation can be described by the principle of depth filtration in the given medium. The term filtration kinetics refers to the time behaviour of the separation efficiency of the entire filtering layer, which includes both the given medium and the deposited particles in the medium. If the dust separation on a given filter medium is carried out for a sufficiently long time, a dust cake is formed after a completed clogging phase, which is often a gradual process. A fully formed dust cake on the given filter medium has, in addition to the core region of the cake, in which the packing density practically no longer changes, a highly porous packing section on its surface, which has a characteristic, stable height profile of the packing density in the direction of the gas flow. This packing section on the surface of the dust cake acts as the actual, active separation zone of the cake for the coming dust particles, since hardly any particles penetrate into the core region of ​​the cake below. Therefore, with surface filtration which is named in relation to the original filter medium, there is always a special, highly effective depth filtration in the highly porous packing section of ​​the dust cake on the microscopic level. This special depth filtration achieves a dynamic equilibrium of the filtration kinetics in which the structure of the active separation zone in the sense of a filtering layer no longer changes.

In this study, the overall filtration process is therefore viewed from a completely new perspective: There is a continuous, systematic change in the active separation zone of a given filtering system which is transformed from the initial clean filter medium via continuous particle separation under the given filtration conditions to a new, dynamically preserved stable porous structure – this is the active separation zone of the dust cake. Results from 3D simulations of cake formation on filter models for fabric filters are evaluated and converted into a dimensionless form to describe structural changes in the filtering layer during the overall filtration process. Possible approaches to describe this systematic change mathematically are presented and discussed...

Learn More at FILTECH 2023 Conference - Register Now!

Development of a cyclone sampler using CFD

D. Misiulia*, S. Antonyuk, University of Kaiserslautern-Landau, Germany; G. Lidén, Stockholm University, Sweden

Personal cyclone samplers have been widely used to measure the respirable mass of particles in occupational and ambient environments. In respirable dust sampling, it is essential that the cyclone cut-off characteristics be known and constant, and that each cyclone be operated at a flow rate which produces the desired cut-off. The personal sampling methods used today comprise air flows up to 10 l/min. The aim of this work is to develop a 20 l/min sampling cyclone that meet the respirable convention. This was realised by using Computational Fluid Dynamics (CFD).

The particle-laden flow within cyclone samplers has been investigated with LES applying a dynamic Smagorinsky-Lilly subgrid-scale model. The air phase was treated using a Eulerian approach while the Lagrange method was applied to model the movement of particles, which were tracked through the cyclone. CFD simulations have been validated based on experimental measurements of pressure drop and penetration.

Two cyclone designs, Higgins-Dewell (HD) family and GK family, have been computationally investigated at a flow rate of 20 l/min and the flow pattern, cyclone pressure drop and particle penetration have been analysed....

Learn More at FILTECH 2023 Conference - Register Now!


L09 - Filter Presses and Press Filters I

Day: 15 February 2023
Time: 16:45 - 18:00 h
Room 1

Session Chair:
Dr. Anthony Stickland

Scale-up for optimized belt filter press operation

G. Krammer*, Graz University of Technology; R. Raberger, Andritz AG, Austria

Belt filter presses are used for the separation of solid particles from liquids, e.g., in the mining and chemical industry or for dewatering of biological sludge. In a first stage, the free draining liquid of a suspension is removed on a gravity table. This pre-thickened suspension is further compacted by feeding it through two converging filter belts, i.e., the wedge zone to form a filter cake that is sufficiently stable to cope with increasing press forces exerted on the cake during a sequence of subsequent rollers.

Mimicking the belt filter press process, the free liquid was drained before the pre-thickened suspension was compacted by applying normal pressure. The resulting filter cake was fed to a laboratory roller test set-up at conditions typical for large-scale applications. Of course, the laboratory tests were performed with a much smaller suspension quantity resulting in a much smaller filter cake with a significantly larger specific boundary area. A thorough evaluation of the laboratory roller test set-up revealed the sample location and its size that can be regarded as the core area of the filter cake and thus being comparable with the large scale situation. Clearly, the actual stress situation at this sample location is decisive and not the average stress across the entire filter cake. Exemplarily it was found for an initial quadratic sample of 100mm side length that the sample for determining the residual moisture is to be taken from the geometric center of the final, dewatered cake patch with a spherical sample size of 50mm diameter to ensure a cake thickness variation of less than 5%.

A conflict of interest arises when both throughput and cake dryness strive for a maximum. However, also for a targeted cake dryness, the corresponding maximum, i.e., optimum throughput needs to be identified...

Learn More at FILTECH 2023 Conference - Register Now!

High pressure dewatering rolls Mk-II: A novel dewatering technology for mineral tailings

S. Hassan*, N.I. K. Ekanayake, P.J. Scales, Robin J. Batterham, A.D. Stickland, University of Melbourne, Australia

The mining industry is considered to be the largest producer of waste in the world, creating around 8.85 billion tonnes/year of tailings (Baker et al., 2020). In Australia, 11% of total water consumption is used for mining operations (1250 GL/y), a significant proportion of which ends up in tailings storage facilities. There are several different techniques for solid-liquid separation such as centrifugation and thickening but for tailings with fine particles, these technologies are not able to achieve a high solids concentration. This is essential to decrease water use in the industry and provide safer tailings storage. The only technique available that achieves a reduced water and tailings footprint is high pressure filtration.

The increase in solid concentration during dewatering processes for fine particulate (compressible) suspensions is limited by two factors, namely the rate and extent of dewatering. The equilibrium cake solids concentration is dependent on the pressure applied, and the liquid permeability decreases as the solids concentration increases. In general, suspensions with finer particles have lower equilibrium solids concentration compared to coarser particles for the same applied pressure, since smaller particles have more particle-particle interactions to form a continuous load-bearing network. The permeability of liquid through suspensions containing finer particles is also lower as there is more surface area causing fluid drag. This makes the filtration of suspensions containing finer particles much harder than coarser suspensions. With increasing production of minerals and finer grinding of ores, the amount of fine particles present in mineral tailings is increasing and high pressure equipment is required to achieve improved solid-liquid separation.

Plate-and-frame filters or chamber presses are commonly used in many industries for high pressure filtration applications. Unfortunately, they can have high capital and operating costs since they are batch processes requiring considerable ancillary equipment and infrastructure, have fixed plate separation and therefore limited versatility for changing feed types, and can suffer cloth fouling, which requires washing and cloth changing. A novel solid-liquid separation device developed at the University of Melbourne, called High Pressure Dewatering Rolls (HPDR) (Scales et al., 2017, Scales et al., 2018) has the potential to overcome these issues. The HPDR has two semi-permeable rotating rolls that are under vacuum. As the rolls rotate, suspension in the feed chamber is filtered and cake forms on the surface of the rolls. Further rotation forces the filter cake through the small gap between the rolls where it is compressed under high pressure. The HPDR is a continuous filter with adjustable filtration path length and no filter cloths. The high pressures are capable of overcoming the strength of the interparticle interactions and thus achieve high solids concentrations, while the short and adjustable filtration path length overcomes any permeability-limited filtration problems. The rolls are independently-driven such that shear can also be incorporated through asynchronous roller speeds, which helps increase the cake solids concentration. An added benefit is that larger scale devices are implied to have the same filtration path length at the nip, simplifying scale-up issues.

A initial Mk-I prototype was trialled using a range of compressible industrial suspensions (Höfgen et al., 2019) and shown to achieve comparable cake solids concentrations as conventional high pressure filters. While the rollers for the Mk-I prototype were designed for fibrous suspensions from paper recycling and had 500 µm slots for filtrate drainage, fine particle suspension dewatering was demonstrated by retrofitting a wedge wire with 50 µm gaps. Unfortunately, subsequent equipment failure indicated roller redesign was required. Likewise, only 90° of the roll surface was used for filtration. The Mk-II HPDR prototype, presented here, is designed and manufactured specifically for mineral tailings, overcoming the Mk-I’s limitations with a higher effective filtration area and allowing for finer particle filtration. It has four times the effective...

Learn More at FILTECH 2023 Conference - Register Now!

Cake desaturation optimisation in filterpress process: an experimental approach

F. Kaswalder*, N.M. Finocchiaro, A. Grosso, Diemme Filtration Srl, Italy

Cake desaturation, carried out by pressurized air insufflation inside the filtration chamber, represents in most cases a crucial step of the dewatering process of a filterpress.

Generally speaking, there are two main reasons for this requirement: obtaining a compact and manageable cake, avoiding liquefaction and thixotropy, and/or getting an additional moisture removal in order to meet the required dryness.

These aspects are of upmost importance especially in mining applications, where a combination of large throughputs and high dewatering performances make the process optimization remarkably challenging. Current trends show that the capacity demand of filterpresses for mine tailings dewatering is constantly increasing. Diemme filtration biggest filterpress, especially designed for this application, can guarantee a throughput up to 10000 ton per day of processed solids.

From this point of view, a proper tuning of desaturation conditions is crucial, considering their significant impact both on CAPEX (size of air compressors and larger filtration area required) and OPEX (energy demand) of the equipment.

In the present work different real cases are considered, carrying out a fine process tuning by means of lab scale pilot filters...

Learn More at FILTECH 2023 Conference - Register Now!


L10 - Advanced Filter Technology for Process Optimization

Day: 15 February 2023
Time: 16:45 - 18:00 h
Room 2

Session Chair:
Dr. Marco Gleiß

Saving energy in operating membrane filterpresses during optimizing the filtration prozess with JZ-Analysis-System

J. Zeller*, JZ Engineering GmbH, Germany

In the field of solid-liquid separation, membrane filter plates have been established in filter presses. Using membrane filter presses, a higher solid content of sludge can be achieved compared to other dewatering systems in filtration.

Very often filter cakes have to be dried after the process “filtration”. Drying cakes is done in different machines, for example tumble driers. All of the driers have the similarity that they need energy, usually put in as energy from gas or electricity.

To run industrial processes economically, the target has to be, to spend as less energy as possible for drying.

With the developed JZ-Analysis-System, information in the filter plate pack, a so-called Black Box, are made transparent.

The collected data show immediately the status of all membrane plates. If there is one leaking and squeeze media is lost, the squeeze pressure often is decreased to reduce the amount of lost squeeze media.

If squeeze media gets lost, the Analysis-System will indicate the number of the affected membrane plate and the operator is able to change this plate during the next cake discharge. No additional searching for the plate is necessary.

The result is to be able to keep the squeeze pressure high and therefore to get better solid content in the filter cakes. This means less energy for drying is needed.

Additionally with the system, squeeze media will not be wasted.

Learn More at FILTECH 2023 Conference - Register Now!

ContiLoop Multi-Cycle Cake Filtration Versus Depth Filtration: Eliminating the Downstream Bottleneck

P. Morsch*, D. Stucchi, T. Bucher, DrM, Dr. Müller AG, Switzerland, C. Jerrold-Jones, DrM, USA

In recent years, single-use technology (SUT) has become more established and has contributed to a considerable increase in production efficiency. SUT has particularly excelled in the crisis-ridden, rapid development of production chains. Of particular importance here are disposable bioreactors in the upstream process, which make costly autoclaving processes unnecessary and allow the rapid linking and capacity expansion of individual unit operations through numbering-up strategies. In order to keep up with the great advances in the upstream process, the downstream processes such as filtration and mixing must also increase their capacity and efficiency. However, cell harvesting and downstream processing remain bottlenecks in production.

Typical clarification processes include primary and secondary clarification, e.g. centrifugation and depth filtration. Two sets of depth filters can be used for primary and secondary clarification, but their separation principle (clogging filtration) means that they quickly become clogged and have to be replaced. To avoid large waste flows, which is a disadvantage of the SUT, within a production cycle and to increase the flow rate, a cleanable filtration module is a remedy. To achieve this, it is necessary to switch to regenerable cake filtration. This principle is followed by the "filter in a bag" (CONTIBAC® SU), which allows cake discharge within a production cycle (multi-cycle) and thus increases the filtrate flow rate by a factor of 3. In addition, clogging of the modules is avoided and a single module can clean a higher process volume with a significantly larger solids content. In addition, this technology allows the combination of primary and secondary steps in one filtration step.

In this presentation we will compare this novel technology with already known SU filtration technology, the depth filtration. This evaluation will be based on flow rates, production yield, filtrate quality and space requirements. In addition, a process with a high solids content is used to show the advantage of this technology especially for cell harvesting of thick suspensions. In addition to a process-technical analysis of the technology, a commercial consideration of the use of these filters is also carried out...

Learn More at FILTECH 2023 Conference - Register Now!

Dynamic cross flow filtration with metallic filter media - Versatile, new process solutions: classification, clarification, concentration

E. Ehrfeld*, BOKELA GmbH, Germany

In contrast to classic crossflow filtration, in dynamic crossflow filtration with the BoCross filters (formerly Dyno Filter), the typical tangential overflow of the filter surface is not generated by the geometric flow control in the apparatus, but by rotors. This principle offers decisive process advantages. There are almost ideal physical conditions for the separation process. The throughput is therefore up to 10 times greater than with classic crossflow filtration. Furthermore, it is also possible to process suspensions with high concentrations or viscosities, because there are no narrow spaces and gaps.

In particular, the use of metallic filter media in dynamic crossflow filtration with the BoCross filters enables versatile and completely new process solutions. For tasks such as classifying, clarifying liquids and concentrating solids, these new processes offer powerful solutions where state-of-the-art technologies such as wedge wire screen, candle filters, backflush filters, vibration screens, centrifuges or membrane filters reach their limits.

Depending on the task, the BoCross filter technology can be used to implement various procedures tailored to the product and objective when using metallic filter media. For example, a particle “ground” layer on the filter medium can be reliably prevented or specifically generated. In this way, innovative processes such as for example, dynamic sieve filtration and dynamic precoat filtration can be implemented. With the dynamic sieve filtration, disruptive coarse particles can be continuously screened out suspensions with a sharp separation cut, even of highly concentrated or highly viscous suspensions. Dynamic precoat filtration, on the other hand, makes it possible to completely separate solids and thus produce absolutely clear filtrates. The ground layer in this precoat filtration is usually...

Learn More at FILTECH 2023 Conference - Register Now!


F04 - Innovative Media Development and Optimization

Day: 16 February 2023
Time: 09:00 - 10:15 h
Room 3

Session Chair:
Dr. Ralf Kirsch

A digital framework for pleat optimization

A. Wiegmann*, L. Cheng, E. Glatt, D. Mosbach, S. Linden, P. Eichheimer, M. Azimian, Math2Market GmbH, Germany

Computer-Aided-Design (CAD) is used by filter makers to speed up manufacturing of filters and filter elements. In this context, modelling pleats with multilayered materials and varying pleat counts can be so tedious that very few designs are manufactured and tested.

CAD data may also be used as input to simulations to predict the pressure drop, filter efficiency and filter lifetime. We present a simulation framework that starts with the CAD data but then permits automatic parameter studies on the pleats. Compared to other methodologies, our 3d image-based approach works completely automatic and requires no manual meshing steps before the simulations can run.

As example, we simulate a filter with different pleat counts and volumetric flow rates to find the local minimum of the pressure drop. The approach finds the right balance for the pleat count between lowering the pressure drop by providing more filter area and raising the pressure drop through capillary forces in the inflow and outflow channels between the pleats. This allows...

Learn More at FILTECH 2023 Conference - Register Now!

New developments in woven wire filtration media: 3D high perfomance filter cloth; woven wire mesh combinations in solid-liquid separation

F. Edelmeier*, F. Meyer, Haver & Boecker, Germany

Previous filter cloths with small pore sizes lead to reduced flow rates and significant pressure loss in the production process. The cloth structure of a newly developed three-dimensional weave increases the number of pores and thus the open surface over the same area. For a given pore size, the flow rate is more than doubled compared to conventional Dutch Weaves. The pore size within a batch can be calibrated as desired from 5 µm to 40 µm.

Conventional woven wire filter cloths can cause turbulences that affect the filtration process at high flow rates. Turbulences with the 3D-filter cloth is effectively avoided. Its pore size can be calculated precisely in advance and adapted to the respective requirements. The mathematical formulae for determining permeability were developed in cooperation with the University of Stuttgart within the scope of AVIF projects A224 and A251, and experimentally validated by glass bead tests and air flow-through measurements.

These predictable pore sizes can achieve extremely high cut-points and dimensional stability. The depth structure of the new woven wire filter cloth facilitates high separation efficiency without rapid blinding. This leads to longer filtration processes between cleaning intervals and longer service life for greater production reliability.

The 3D metal filter cloth is woven from standard diameter wires. Moreover, it is possible to weave special materials such as Alloy 310 S, Hastelloy C 22, Inconel 600 or titanium even in the small pore range. Thus, for the first time, filter cloth with pore sizes below 40 µm can be manufactured in corrosion- and temperature-resistant alloys...

Learn More at FILTECH 2023 Conference - Register Now!

Conjugated microporous polymers from [3+2] and [4 + 2] cycloaddition reactions: prominent adsorbent materials of iodine and cationic dyes

B. Alameddine*, Gulf University for Science and Technology, Kuwait

New conjugated polymers are prepared from a palladium-catalyzed cyclopentannulation reaction using a series of specially designed monomers. The target materials display high solubility and excellent chemical stability along with high relative weight-average (Mw) molecular weight in the range of 15.8 to 34.3 KDa with a polydispersity index (Đ=Mw/Mn) of ~2.5. Investigation of the iodine adsorption properties of the resulting copolymers reveals...

Learn More at FILTECH 2023 Conference - Register Now!


G12 - Indoor Air Cleaning

Day: 16 February 2023
Time: 09:00 - 10:15 h
Room 2

Session Chair:
Prof. Paolo Tronville

Investigation of indoor air cleaners in realistic scenarios by experiments and three-dimensional simulations

S. Schumacher*, K. Varzandeh, T. Hülser, C. Asbach, Institute of Energy and Environmental Technology e.V. (IUTA); C. Luzzato, J. Jilesen, Dassault Systemes Deutschland GmbH, Germany

Indoor air cleaners are widely used to improve the indoor air quality and can contribute to reducing infection risks by filtration of virus-carrying droplets. There are several test standards using sealed, well-mixed and unfurnished chambers to determine the clean air delivery rate (CADR) as a measure for the cleaning performance. However, there is only limited knowledge on how the results transfer to real applications and how several air cleaners in the same room interact with each other. Moreover, the detailed distribution of cleaned air can be experimentally obtained only with low spatial resolution. Here, computational fluid dynamics (CFD) simulations can deliver additional information after a validation with experimental results. To address these aspects, we considered three scenarios typical for the application of air cleaners.

Firstly, we investigated the effect of the position of the air cleaner in a 63 m³-sized meeting room. Paraffin particles were dispersed with an atomizer and the decay of the particle concentration measured in different size ranges and at different locations without and with one or more air cleaners operating. We show that the cleaning efficacy is nearly independent of the position of the air cleaner. The cleaned air can be homogeneously distributed even in the presence of flow obstacles such as acrylic glass sheets, which are often used to prohibit direct infections between individuals. Furthermore, we demonstrate that the combination of two air cleaners operated at a lower flow setting can have the same cleaning effect as a single air cleaner at higher flow setting, but at a lower power consumption and less nuisance due to noise.

In a second step, experiments in a 200 m³-sized classroom were performed. Firstly, the most realistic situation with about 30 pupils in the room, inducing a natural airflow by their body heat and activities, was considered. In this case, particles entering the room when opening the windows were used as test aerosol. After closing the windows and operating the air cleaner, the decay rates were measured to determine the CADR. For comparison, measurements in the unoccupied room using an artificial source of NaCl particles were performed. We show that both measurements are in reasonable agreement. This means that the efficacy of an air cleaner can be determined to good approximation on site using surrogate particles and without the presence of persons in the room.

Finally, a 260 m³-sized open-plan office equipped with two identical indoor air cleaners was chosen to validate numerical simulations with experimental data. While many studies in the past have used Reynolds Averaged Navier Stokes (RANS) approaches for predicting the particle propagation, the turbulence length scales accurately captured in these simulations might not be sufficient to provide a realistic spread and mixing of particles under the effects of forced convection. Thus, here a Lattice Boltzmann Very Large Eddy Simulation (VLES) approach was applied. We investigated both the cleaning of an initially contaminated room as well as the steady state situation reached in the presence of a continuous particle source. Both simulations and measurements with salt aerosol particles were...

Learn More at FILTECH 2023 Conference - Register Now!

Combining ionization and filter material for aerosol separation: Basic studies

M. Lauer*, R. Heidenreich, Institute of Air Handling and Refrigeration (ILK); C. Lerche, Ingenieurbüro Dr. Lerche GmbH; H. Siegmund, RL Raumlufttechnik und Raumluftqualität GmbH, Germany

Though particles below 0.3 µm are not considered in ISO 16890 filter classification, they are critical to human health because of high number concentrations in ambient air, respirability and lung deposition together with the ability to cross the blood/brain barrier. Increasing air filter efficiency usually requires denser filter material when using only mechanical filtration principles, which leads to higher energy consumption of ventilation devices in the system. Filters based on mechanical separation usually show a minimum efficiency between 200 and 400 nm, which can only be increased on the cost of high air resistance of the filter medium. Therefore, alternative principles combining low pressure drop and high removal efficiency are of interest, such as electrostatic aerosol separation. Generating ionized air upstream of a standard coarse filter material is supposed to improve filter performance significantly, especially at nanometre particle size range.

The aim of this research was a better understanding of ionization induced aerosol separation principles, as well as of interactions and dependencies with existing technical components. Based on experimental data, conclusions for the further development and application in air filtration systems should be formulated. Suitable measurement methods had to be developed.

Within the presented study, prototypical components for ionization and standard filtration materials were characterized, the combination of both was investigated at lab scale and basic design principles were derived. The potential of separation improvement by this technology should be quantified....

Learn More at FILTECH 2023 Conference - Register Now!

Inactivation of infectious bioaerosols by dielectric filter discharge

S. Lee*, K.-H. Baek, J.-Y. Park, S. Jung, E.-Y. Byeon, D.-G. Kim, Korea Institute of Materials Science (KIMS); S. Ryoo, Masan National Tuberculosis Hospital; S. Lee, Korea Conformity Laboratories, South Korea

Management of infectious bioaerosols in indoor air has emerged as an important technology due to the COVID-19 pandemic. Bioaerosol management can be divided into physical capture and physicochemical inactivation steps. KIMS is researching technologies to inactivate physically captured aerosols with dielectric filter discharge.

The plasma filter generates surface plasma on the porous ceramic to oxidize the bioaerosol captured in the ceramic foam, and supplies reactive oxygen species including ozone to the polymer filter located at the rear for secondary oxidation. Ozone emission, an inevitable problem of atmospheric pressure low-temperature plasma technology, has been solved through a catalyst, and ozone concentration of 0.05 ppm or less can be maintained for more than 200 hours. It was demonstrated that the SARS-CoV-2 aerosol was inactivated by more than 99% immediately after passing the plasma filter.

In this presentation, we will briefly introduce the developed technologies and report the commercialization results.

Learn More at FILTECH 2023 Conference - Register Now!


L11 - Filter Presses and Press Filters II

Day: 16 February 2023
Time: 09:00 - 10:15 h
Room 1

Session Chair:
Prof. Gernot Krammer

Quantifying the effects of clay on mineral tailings filtration

Y. Luo*, N.I.K. Ekanayake, S.P. Usher, K.P. Hapgood, P.J. Scales, A.D. Stickland, University of Melbourne; N. Amini, E. Moon, Deakin University, Australia

Mineral tailings are typically filtered to recover process water and consolidate tailings for storage. In particular, low moisture contents are required for geotechnically safe dry stacking. Clay and clay minerals are commonly found in mineral ore-bodies and increasingly show negative impacts in processing operation. The amount of clay usually varies with the location across the ore body. As such, the presence of clay in the ore negatively impacts most of the unit operations, including filtration and thickening.

The main issue with clays is their high aspect ratio, which causes a low density in particulate aggregates (large occluded volume) and higher suspension viscosities at any given solids concentration. As a result, hig filtration compression is required to achieve low moisture content tailings, leading to decrease in specific solid throughput and increase filter size required. In this study, the effect of clay in mineral tailings filtration was explored and quantified using a comprehensive dewaterability analysis...

Learn More at FILTECH 2023 Conference - Register Now!

Dehydration performance with filterpress of several hydrothermal treated waste sludges from different origins

D. Pirini*, D. Collini; B-PLAS s.r.l. ; F. Kaswalder, N.M. Finocchiaro, Aqseptence Group s.r.l., Italy

Sludges from agri-food industry, civil and industrial WWT plants are a growing problem throughout the EU, due to a faster production rate than the availability of disposal plants (landfills and incinerators) and due to the tightening of regulatory constraints that make the spreading in agriculture as a soil improver possible. For this reason improving the performance of dehydration technologies for these substrates is increasingly urgent.

In some specialized sectors where the available space is limited, like the cruise ship industry, the sewage sludge and food waste reduction problem is even more crucial and the entire ship depends on the good performances of the solid/liquid separation.

This work reports the comparative study of the dehydration performance of hydrothermally treated sludge by the sludge module of the innovative industrial process B-PLAS®, and others post HTC sludges. The treated samples came from different sources: WWT sludges, sludge from anaerobic digestion of a biogas plant treating agri-food waste and sludge from on-board sewage and food waste in cruise ships.

The study focuses on the first part of the B-PLAS® process (sludge module), evaluating the solid-liquid separation performance by means of a filter press, without the use of polyelectrolytes or other filtration conditioning, depending on the substrate and the operating conditions of the hydrothermal carbonization reactor...

Learn More at FILTECH 2023 Conference - Register Now!

Reliable design and optimization of filter presses easy made by using the FILOS software

I. Nicolaou*, NIKIFOS Ltd, Cyprus

In this paper a novel method for the reliable and user-friendly design and optimization of Filter Presses (including Membrane Filter Presses) by a novel module of the FILOS Software is presented. FILOS is a worldwide unique software and the result of more than 22 years intensive and focused work for the Analysis of filtration test data (including cake washing, cake squeezing and cake deliquoring via gas pressure difference) based on practice oriented theory and for the design and performance calculation of the most important continuous and batch filter apparatuses) : Belt, Drum, Disc, Pan filters as well as Nutsche, Candle, Pressure Leaf Filters, Filter Presses and Filter Press Automats.

The reliability of the Design and Optimization of Filter Presses but of any other filter apparatus mentioned above is due to the FILOS-Analysis modules for cake formation, washing, squeezing and deliquoring, which enable the correction of test data due to theory based diagrams and the correct determination of the necessary material parameters for the given suspension (called efficiency parameters), which are necessary inputs for the filter simulation modules. Only then is possible to have reliable values for the main performance parameters: solids mass throughput, cake moisture content and wash out content of the washed, squeezed and deliquored cake or reliable calculation of the needed filter area for given filter performance...

Learn More at FILTECH 2023 Conference - Register Now!


M04 - Transport Mechanisms

Day: 16 February 2023
Time: 09:00 - 10:15 h
Room 4

Session Chair:
Dr. Thomas Peters

Multidimensional particle fractionation using a crossflow and an electrical field

S. Paas*, P. Lösch, K. Nikolaus, S. Antonyuk, University of Kaiserslautern-Landau, Germany

The increasing demand of fine particles < 10µm in suspensions is leading to new processes which can provide such dispersed particle collectives [1]. Existing separation processes like hydrocyclones, centrifugal applications or crossflow fractionation face the challenge of achieving the desired particle size without a high energy and/or time consumption.

In this contribution, a cross-sectional fractionation technique is being presented, which is a promising method for the highly specific separation of micro suspensions...

Learn More at FILTECH 2023 Conference - Register Now!

Development of a simulation tool to accelerate the design of forward osmosis processes

B. Greisner*, D. Mauer, MionTec GmbH; F. Rögener, TH Köln; A. Lerch, TU Dresden, Germany

Forward osmosis is a promising membrane process that has recently received a lot of attention from researchers. Most publications have focused on the draw solution, fouling, energy consumption and recovery system, and only a few on modelling/simulation and techno-economic analyses. In order to convince decision makers from industry of the yet little used technology, there is a high need for diverse pilot scale trials and demonstration projects [1]. The authors’ research aims to develop an engineering tool for the design of forward osmosis processes in order to accelerate applied research and to create data for economically promising studies.

In this particular presentation the authors present their progress in the research made so far, wherein they managed to numerically model the thermodynamic properties of known highly concentrated single electrolyte solution applying Bromley’s equation over a concentration process. Furthermore, approaches are discussed on how to simulate substance systems of unknown composition...

Learn More at FILTECH 2023 Conference - Register Now!

Why surface charge is important for filters operated by size exclusion

T. Luxbacher*, Anton Paar GmbH, Graz, Austria

In liquid separation, pore size and pore size distribution generally determine the retention and water flux of membranes or filters for depth filtration and microfiltration processes. However, for solutes with a size smaller than the filter pores, the electrostatic interaction with pore surfaces is the driving force for their retention. Tuning the surface charge is then key for a successful application of such filters and membranes. Besides the enhancement of solute retention by electrostatic attraction, repulsive forces decrease the affinity of membranes and filters towards foulants in the feed solution and improve the filtration conditions. Knowledge about the surface charge is thus compulsory to predict the performance of sterile filters for protein purification, microfiltration membranes for virus retention, or capillary membranes for haemodialysis. This contribution introduces the concept of surface charge analysis by determining the zeta potential at the filter-water interface and presents case studies for the application of this solid-liquid interfacial parameter to predict protein fouling and virus retention...

Learn More at FILTECH 2023 Conference - Register Now!


F05 - Media Deformation - Modelling and Simulation

Day: 16 February 2023
Time: 10:45 - 12:00 h
Room 3

Session Chair:
Dr. Ralf Kirsch

Simulation and characterization of deformed filter media on the fiber level

K.M. Höss*, F. Keller, C. Schulz, MANN+HUMMEL GmbH; S. Schmauder, University of Stuttgart, Germany

Dust holding capacity, filtration efficiency, and pressure drop are the main parameters used to measure the filtration performance of flat filter media [1]. These parameters directly depend on the properties of the microstructured fiber network, such as the local pore distribution, fiber diameter distribution, or fiber surface distribution, amongst others. Filtration simulations with selectively modified microstructural properties can help to determine new structures with optimized filtration performance [2]. However, the effective mechanical properties of the new fiber network are unknown at this point in the filter media design process. In order to achieve the required active filtration area in the given design space, it is often necessary to pleat the filter media. The processing into the finished filter bellows places particular demands on the mechanical deformation behavior. Furthermore, the processing itself alters the microstructural properties of the fiber network and, thus, influences the resulting filtration performance.

Therefore, the ability to predict these anisotropic mechanical properties of a microstructural fiber network is crucial for assessing the processability of the new microstructural designs. Mechanical microstructure simulations can help not only to estimate the highly anisotropic elastic-plastic material behavior of these fiber networks but also help to estimate the change in filtration performance based on the modified fiber network. The software GeoDict serves as a virtual laboratory to characterize these fiber networks and to determine their mechanical properties in all three spatial directions under tensile, compressive, shear, or even bending loads.

This presentation introduces a microstructural simulation model for predicting the three-dimensional elastic-plastic behavior of synthetic fiber networks...

Learn More at FILTECH 2023 Conference - Register Now!

Efficient simulation of flow-induced deformation of woven filter media

M. Krier*, R. Kirsch, C. Mercier, J. Orlik, S. Rief, K. Steiner, Fraunhofer Institute for Industrial Mathematics (ITWM), Germany

In more and more areas of filtration, the flow-induced deformation of filter media is a phenomenon that has to be taken into account when optimizing the design of filter elements. Computer simulations can accelerate the development and optimization, but since most state-of-the-art simulation models for the flow in filter elements assume rigid media, the computed results can differ a lot from experiments. A common problem in the modelling of woven filters is the huge ratio of length scales due to the comparatively large bulk fluid domains and the thin filter media with complex microstructure. Direct numerical simulation with the fibres resolved in the computational grid require a tremendous amount of hardware resources, if practical at all. For nonwoven filter media, the classical Taber model for poroelastic plates can be used for the efficient numerical simulation of Fluid-Porous-Structure-Interaction (FPSI) (see e.g. [1]).

By design, woven filters feature a periodic structure on the microscopic scale, and it seems straightforward to use this fact for the replacement of the resolved microstructure by an effective, 2D poroelastic plate or shell, such that the computational effort reduces drastically. In the presented work, an asymptotically based efficient model for the interaction of stationary laminar incompressible flow with deformable woven filters is derived. In contrast to nonwovens, the mechanical properties of the woven medium can be computed and therefore, time-consuming and extensive testing is not necessary...

Learn More at FILTECH 2023 Conference - Register Now!

Flow-induced deformation of nonwoven filter media: Experiments, modeling and simulation

R. Kirsch, J. Köbler, N. Henkelmann, Fraunhofer Institute for Industrial Mathematics (ITWM); S. Antonyuk, V. Puderbach*, M. Weirich, University of Kaiserslautern-Landau, Germany

During operation of filter elements, it is observed that the fluid flow causes deformations of the filter media which can lead to well-known (and undesired) effects like pleat collapse, pleat crowding etc. In such cases, filter designers are facing the additional challenge to provide stabilizing countermeasures such as spacers, supporting ribs and pleat holders without sacrificing too much available media surface area.

Finding a good design by building and testing prototypes can become very costly, so it seems natural to use computer simulations to optimize countermeasures like those mentioned above. However, most simulation models assume “rigid” filter materials. Therefore, suitable models and simulation methods for the Fluid-Porous-Structure Interaction (FPSI) are desired to obtain more realistic predictions of the filter media deformation for a given design variant. This requires a better understanding of the mechanical properties of nonwoven filter media. More precisely, the material laws governing their behaviour when subjected to volumetric forces need to be known. The question arises whether the material characterization based on “dry” experiments such as the usual tensile, bending and compression tests are sufficient for the prediction of the deformation when the fluid flows through the porous.

To investigate this, several media used in liquid filtration were characterized in terms of air permeability and structural mechanics. For the in-situ measurement of the deformation caused by stationary, laminar flow, a suitable test bench was designed and built. The test bench setup and first data obtained for flat sheet samples were...

Learn More at FILTECH 2023 Conference - Register Now!


G13 - Indoor Air Quality

Day: 16 February 2023
Time: 10:45 - 12:00 h
Room 2

Session Chair:
Prof. Paolo Tronville

Energy-efficient operating concepts for air purification with cooperative ventilation systems based on simulations, sensor data and artificial intelligence

L. Bittel, S. Berger, J. Niessner*, L. Springsklee, Heilbronn University of Applied Sciences; M. Lehmann, MANN+HUMMEL GmbH; F. Pagliarini, ebm-papst neo GmbH & Co. KG, Germany

Both stationary ventilation systems and mobile air purifiers can remove potentially harmful aerosol particles from indoor air by either capturing them in a highly efficient filter medium or by exchanging aerosol-laden air with fresh air. During the pandemic, focus on health protection was typically the most pressing need - often without taking the energy efficiency of the measures into account or adapting volumetric fluxes, and thus, energy consumption, to the actual or current aerosol pollution.

Therefore, the aim of the funded project ESTATE is to evaluate for a given demonstration room various scenario for reducing particle concentration with regard to their energy efficiency. Measures to improve energy efficiency are considered at both component and system levels. Reference cases will be developed combine measures for optimal performance w.r.t. energy efficiency and air quality level. Measures are evaluated based on digital technologies such as sensor networks, flow simulation and cloud-based data analysis. Improved energy efficiency at both component and system levels is to be achieved through the further development of technology and in combination with artificial intelligence. The results should provide building blocks for the COVID-19 pandemic in the short term and for potential future infectious diseases that can be transmitted by aerosols in the longer term, which offer a stable level of health protection and actively promote the achievement of climate targets through CO2 savings using digitalised, energy-efficient solutions.

A progress report of the ongoing research will be presented, using thermal manikins and a spatially resolved sensor network comprised of sensor nodes that are able to monitor air quality, and the air velocity vector. The transport of aerosol particles will be studied inside a lecture hall under three different configurations: using the hall’s own stationary air handling unit, using a mobile air purifier, and using both. In addition to aerosol particle concentration, the results of thermal comfort will be presented along with environmental parameters such as temperature, relative humidity, and CO2 concentrations. Finally, CFD models will be setup and validated for both aerosol particle transport and thermal comfort, as defined by predicted mean vote (PMV) and percent of persons dissatisfied (PPD) parameters. Based on heatmaps of the clean air delivery rate, the critical response time of the sensors, and of PMV and PPD we show that...

Learn More at FILTECH 2023 Conference - Register Now!

A comparative study on air filters to improve indoor air quality

I.S. Akgün Güldür*, A. Tüter, M.M. İlgün, Arçelik A.Ş, R&D Center, Turkey

With the continual increase in air pollutants due to industrial and technological activities, air quality has become an important area of concern in recent years [1]. Particularly, high number of pollutants have been detected in indoor air which may be two to five times higher than the outdoor level. These pollutants which are mostly particulate matters (PMs) with harmful microorganisms have posed a great threat to human health [1,2]. One of the promising methods to remove PM from indoor air is using air filters in air conditioners whereas air conditioner with UV module can be an effective device to kill pathogens [3]. For PM reduction, porous and fibrous filters particularly high-efficiency particulate air (HEPA) filters, intense field dielectric (IFD) filters and electrostatic filters have received a great attention since they effectively capture PM and maintain low pressure drop at air conditioners [4]. HEPA filters capture particles via adsorption. IFD filters work as a magnet to pull particles out of the air with electric field as they travel through the filter. Electrostatic filters are mostly positively charged filters and capture negatively charged PM which obtained via an ionizer. However, the best filter with high PM reduction capacity, low energy consumption, high selectivity and zero by-product invention is still unclear and there are various standards to follow. Therefore, it is necessary to investigate a comparative study among the filters to decide the best filter for PM reduction via providing microorganism elimination. In this study, we explored PM reduction performance of HEPA, IFD, electrostatic filters. Performance of filters were tested in an air-conditioner and effects of PM concentration in the air and slot number of filters on their PM reduction performance were investigated. For electrostatic filters, effects of presence and number of ionizer, position of ionizer on air conditioner and the distance between the ionizer and the filter were also examined. Microorganisim removal functionality...

Learn More at FILTECH 2023 Conference - Register Now!

Simulating contamination distribution in cleanroom environments

A. Chakraborty *, J.M. Lobert, Entegris, Inc., USA

Cleanrooms are critical environments in many industries, such as micro-electronics and pharmaceuticals. Contamination control has been a necessity for semiconductor processing since its beginning more than 50 years ago. Over time, the semiconductor industry has evolved cleanroom designs to minimize impact of Airborne Molecular Contamination (AMC), gas-phase chemicals of organic and inorganic nature, typically at parts per billion (ppb)-level ambient concentrations. AMC is introduced from outside and from internal sources and dispersed into the cleanroom environment, where it can cause damage to process tools, induce defects and reduce product yield.

To minimize airborne contamination and localize its impact, semiconductor cleanrooms are operated under laminar air flow from top down, entering through ceiling Fan Filter Units (FFU) and exiting through open floors. AMC filters are employed in conjunction with ULPA particle filters on top of FFUs to adsorb AMC. However, laminar flow patterns of the incoming air are often disrupted and altered by the process tools spread out over the cleanroom area. Therefore, to maintain ultra-pure air quality of the clean room, it is important to understand AMC concentrations and flow profiles around the process tools such as scanners, clean tracks and metrology tools.

Computational Fluid Dynamics (CFD) modeling has been proven to be an efficient and productive tool to understand physical behavior of air flow and airborne contaminant concentrations in cleanroom environments. CFD can be employed to create virtual prototypes of cleanrooms and offers insights into air flow and AMC concentration profiles through the interaction of mathematical models with varying cleanroom layout parameters.

This study demonstrates a CFD modeling approach to simulate air flow patterns and the distribution and mixing of AMC in semiconductor cleanrooms...

Learn More at FILTECH 2023 Conference - Register Now!


L12 - Lab Scale Cake Filtration - Equipment and Fundamentals

Day: 16 February 2023
Time: 10:45 - 12:00 h
Room 1

Session Chair:
Prof. Antti Häkkinen

Influence of the measurment resolution on the filtration properties - A comparison of two test setups

N. Benz*, P. Lösch, S. Antonyuk, Technische Universität Kaiserslautern, Germany

In addition to the actual filter apparatus, the filter media are crucial for the filtration tasks. Solid-liquid separation processes often use a variety of fabrics, nonwovens or membranes with different mesh and pore sizes. The layout of filtration applications thus requires specific knowledge of the filter media to be used in interaction with the prevailing particle systems. In order to reliably determine characteristic properties such as the filter cake and the filter medium resistance during cake filtration, corresponding laboratory tests are necessary, which are carried out with the pressurized housing cell standardized in VDI 2762 [1]. In the standard test setup, the exact starting point of the filtration can only be determined afterwards when evaluating the filtration results. This is due to the fact that the filtrate is discharged from the pressurized housing cell via a downpipe and cannot be determined in terms of quantity in the apparatus itself. Instead, the filtrate obtained during filtration is collected in a container located on a laboratory balance. Afterwards the filtrate volume flow rate is calculated via the change in mass over time. Also, the measurement equipment and specific parameters such as the measuring speed and the resolution required for the measurement is not specified in more detail in the VDI 2762. For reproducible measurements and an exact detection of the filtration start, an improved test setup is presented in this contribution, which shows the influence of the measuring speed in interaction with the resolution of the available measuring equipment. Measurements with and without a particle system were carried out to prove that the filter media and filter cake resistance is influenced by the measuring equipment itself. It will be shown that the initial course of the filtration line in the t/V-V diagram, which is often assumed to be non-linear, is influenced...

Learn More at FILTECH 2023 Conference - Register Now!

Modeling of nonideal cake filtration by regression of simulation results

T. Buchwald*, H.K. Gunda, U.A. Peuker, Technical University Bergakademie Freiberg, Germany

Evaluation of filter medium resistance and filter cake resistance is usually achieved through linearization of the filtration equation. In a presentation at Filtech 2022, the advantages of the nonlinear regression method were shown. Discrepancies between the two methods can be and were shown to derive from the neglect of a time offset, which accounts for nonideal filtration behavior at the beginning stages of filtration.

These nonidealities were further investigated by using an iterative simulation, the results of which can than be fit via nonlinear regression to experimental data. This is done to find the optimal model equations which are superposed onto the cake filtration mechanics. While some superpositions could in theory be achieved analytically, the resulting equations are tedious to use because of their sheer size. By trying various model equations to model the compressibility of the cake structure, for example, insights can be gained into the description of a model system.

The talk explains how the iterative cake simulation leads to equivalent results compared with the use of analytic expressions. After establishing how these results can be used in nonlinear regression to achieve the optimal results of the simulation for a given experiment, additional models are shown to account for nonidealities in cake filtration, such as compressibility and sedimentation. Conclusions are drawn regarding the applicability of certain model equations...

Learn More at FILTECH 2023 Conference - Register Now!

Cooling of filter cakes by evaporation of water in vacuum dewatering

T. Kinnarinen*, A. Häkkinen, Lappeenranta-Lahti University of Technology LUT, Finland

This study focuses on dewatering of different mineral slurries in a laboratory-scale vacuum filter. The objective of the study is to demonstrate the applicability of cake surface temperature measurement in monitoring the cake desaturation (i.e. dewatering) process. In this experimental study, various process samples obtained from mining industry were investigated. The filtration and dewatering tests were carried out at room temperature, by applying different pressure differences in the batch vacuum filtration system. The acquired process data comprised filtration curves, average temperature profiles, thermal images, and air flow rates. The cake moisture contents were determined experimentally, and the filtrate accumulation data was used to calculate the moisture content at different times. The results show that...

Learn More at FILTECH 2023 Conference - Register Now!


M05 - Metal and Ceramic Membranes

Day: 16 February 2023
Time: 10:45 - 12:00 h
Room 4

Session Chair:
Dr. Qian Zhang

Ultrafast laser precision drilling of metal and polymer membranes using multibeam scanner and UV-microscanner

P. Bremer*, M. Osbild, M. Reininghaus, Fraunhofer Institute for Laser Technology ILT, Germany

In the field of laser micro and nano structuring, ultrashort pulse (USP) laser processing is attracting increasing attention due to its ability to produce precise hole patterns with highest quality requirements. The multibeam scanner (MBS) enables laser processing with strong parallelization of more than 200 beams for high throughput while maintaining the same drilling quality. The UV-microscanner enables the most precise direct laser drilling of polymers due to its tight focus down to <1 µm and the low heat impact.

The aim is to apply the latest research results and years of process development to new market requirements for laser-drilled membranes such as stainless steel micro filters or perforated polymer membranes in general. The use of USP lasers offers the possibility to produce membranes from stainless steel or polymer films with <1 µm holes. The use of the produced filters is also conceivable for special applications, e.g. as atomizer module in inhalation devices for targeted dosing of antiviral medication or for test device calibration...

Learn More at FILTECH 2023 Conference - Register Now!

Continuous cell cultivation with the perfusion crossflow fermenter (PCF)

G. Grim*, ANDRITZ Separation GmbH, Germany

Fermentation processes can be intensified by extension of the fermentation duration. Higher cell densities or a longer active cell can be achieved if an exchange of liquids is possible, and an intensive aeration is possible. To enable such extended fermentation processes, standard fermenters might be upgraded to the new functions.

The main new task is to remove liquid components from the fermentation broth by simultaneously keeping the cells within the broth. Such sort of “spent” fermentation broth contains the metabolism product of the cells and eventually the target protein. To achieve a constant process volume and steady state process a separation process is required.

To allow higher cell densities and therefore to benefit from the new function of removing liquid components, also the supply of Oxygen has to be intensified.

The key to success is a combination of both new functions. Ceramic membranes allow such sort of media transport in both directions.

Learn More at FILTECH 2023 Conference - Register Now!

Slurry photocatalytic ceramic membrane reactor using Bi2O3/WO3 composite for petrochemical industry wastewater treatment containing phenolic compound through visible-light-driven reactions

Z. Sadeghian*, Research Institute of Petroleum Industry (RIPI); M. R. Akrami, N. Ashrafizadeh, Iran University of Science and Technology (IUST), Iran; K. Sadeghian, University of Kaiserslautern-Landau, Germany

Various photocatalysts, such as titanium oxide and zinc oxide, have been used for the catalytic oxidation of organic pollutants in wastewater. Furthermore, ceramic membranes coupled with suspension photocatalyst is an effective technology that could be substituted with conventional treatment. Also, it was revealed that an integrated photocatalysis–membrane hybrid system is an effective method for decreasing flux decline to irradiation on the membrane surface, could remove organic foulants [1]. Bismuth compounds are novel effective photocatalysts, which can be used in slurry photocatalytic ceramic membrane reactors (PCMR). The Bi2O3/WO3 composite has an efficient photocatalytic activity under visible light and excellent photo and chemical stability for recycling Bi2O3/WO3 composite [2]. Also, it has been proved that an aeration system can increase the contact between the catalyst and visible light in PCMR. Ceramic membranes in the PCMR have good corrosion and oxidation resistance versus oxidizing hydroxyl radicals resulting from the photocatalytic process [3].

In this work, binary Bi2O3/WO3 composite was synthesized using a hydrothermal process, applied with a catalyst dosage of 0.3 g/l and coupled with a ZrO2-modified UF ceramic membrane. The feed phenol concentration was 1000 ppm, and the filtration condition was adjusted in pressure of 3 bar, the velocity of 1.5 m/s and the aeration rate of 0.50 m3 h− 1 under visible irradiation by 500 W xenon lamp. Fig. 1 shows...

Learn More at FILTECH 2023 Conference - Register Now!


F06 - Media Functionalization

Day: 16 February 2023
Time: 13:00 - 14:15 h
Room 3

Session Chair:
Prof. Kyung-Ju Choi

Latest developments in plasma nanocoating technology to functionalize gas and liquid filter media

F. Legein*, Europlasma NV, Belgium

Plasma is a unique technology to deposit ultra-thin coatings on all exposed surfaces of a material or product. It is increasingly used in manufacturing of filtration media and elements to achieve functionalities such as hydrophilic, hydrophobic, oleophobic or dielectric. Improvements in process and machine design allow to deposit the coatings in a very cost effective way, with a process that is completely dry and clean. The technology is giving an increasing number of producers of technical nonwovens, membranes, mesh, nanofibers or film a clear competitive edge.

The paper will start with a short introduction of plasma technology.

Then it will review industrial concepts for both batch and roll-to-roll treatment. It will also compare industrial equipment for atmospheric and low pressure plasma deposition. An overview will be given of typical coating chemistries used for such coatings. Subsequently latest developments will be discussed using real industrial case studies. One case study will discuss the use of hydrophilic nanocoatings for culture growth media. Another case study will review the use of similar nanocoatings for blood filter media. One of the key areas of interest is the nanocoating of electrets used in HEPA filters. A new generation of dielectric nanocoatings (Nanofics®K or ‘Kappa’) specifically designed for electrets will be discussed. Advances in process chemistry allow to deposit coatings which boost and maintain filter efficiency over time, while not affecting the pressure drop. Also advances in water repellent coating of membranes for use in sporting and outdoor jackets will be discussed.

Although today the use of plasma technology for functionalization of gas filter media is well established, the number of industrial applications in liquid filtration is still limited. The paper will elaborate on how the durability of the plasma nanocoatings can be improved, one of the key technological challenges in functionalization of liquid filter media.

The paper will conclude with an overview of the societal and environmental benefits of plasma technology...

Learn More at FILTECH 2023 Conference - Register Now!

Innovative bio-based filtration products made out of functionalised fibres

I. Bernt*; R. Scholz; I. Kaczmarek; M. Crnoja-Cosic, Kelheim Fibres GmbH Germany

The increasing pollution by plastics requires a rapid rethinking in all fields of input materials also for the different types of filtration media used in the industry.

Replacing conventional filter materials with sustainable ones without sacrificing performance is crucial. This becomes especially relevant with more and more fields choosing sustainable filter solutions such as indoor and outdoor air filtering due to increasing pollution effects, filtering of water due to need for purification in different fields and filtering of a wide range of media in industrial and household applications. Especially the replacement of synthetic fibre solutions in single-use filter applications can play a bigger role in the future as regulations such as SUPD show that a ban of plastic can become reality in a broad range of applications.

For many years, Kelheim Fibres has been active in the field of filtration applications with both commercial products and innovative new developments in the field of filtration applications; the use of viscose in papers for tea bags or coffee filters, as well as the research activities precoat filtration are just two examples.

Viscose fibres are cellulosic "man-made" fibres which are plant-based and fully biodegradable. The viscose fibre process offers a wide range of possibilities for the variation of fibre cross-section, fibre dimensions and functionalization and thus allows the production of fibres with a property profile adapted to specific requirements. For example, the porosity and volume of filter papers can be controlled by using suitable fibre dimensions. Chemical functionalization can, for example, introduce ion-exchange capabilities or hydrophobic properties into the fibre and thereby can enhance applicability of filter materials.

Special viscose fibre are thus suitable for a wide range of applications in the growing market of filtration applications.

With our presentation we want to inspire the participants which new nonwovens or paper solutions are possible based on unique and fully bio-based fibre innovations...

Learn More at FILTECH 2023 Conference - Register Now!

Piezoelectric charge transfer phenomena

K.-J- Choi*, Clean & Science Co., Ltd, USA

The piezoelectric effect is the internal generation of electrical charge resulting from an applied mechanical force and vis versa. Electret media by the piezoelectric charge transfer phenomena will be discussed along with theoretical and experimental approaches. It is configured to place the piezoelectric material adjacent the media and to apply mechanical stress to the piezoelectric material...

Learn More at FILTECH 2023 Conference - Register Now!


G14 - Automotive Applications I

Day: 16 February 2023
Time: 13:00 - 14:15 h
Room 2

Session Chair:
Dr. Harald Banzhaf

AeroSolfd – Developing retrofit filtration devices for cleaner urban mobility: A project overview

M.J. Lehmann*, T. Warth, MANN+HUMMEL GmbH; J. Bilbao, Steinbeis Innovation gGmbH, M. Zessinger, Link Engineering Company GmbH; P. Henning, WABCO Radbremsen GmbH, Germany; T. Moreno, Agencia Estatal Consejo Superior de Investigaciones cientificas, Spain; K.A. Jensen, National Research Centre for the Working Environment, Denmark, et al.

Emissions from gasoline engines and brakes of commercial or municipal vehicles as well as by metro or train contribute to health problems and premature deaths. These existing vehicles will continue populating the roads for the next decades emitting PM10/PM2.5 exhaust particles and toxic secondary emissions. For immediate reduction, retrofit filtration solutions for tailpipe and brake wear emissions must be brought to the market. Timing is crucial as retrofits are transition technologies until full electrification of Europe’s transport fleet. But even beyond, brake retrofits may still play an important role in the electrified fleet.

AeroSolfd, a Horizon Europe Innovation Action, addresses quick wins in the reduction of the overall footprint of the existing fleets by developing retrofit filtration devices for tailpipe, brake, and closed environments. The focus is on reducing particle/NOx for tailpipe and brake emissions. This can be filtering emissions at the source (tailpipe and brake) or filtering the air at metro stations as example of semi-closed environments to reduce the overall exposure. Currently, retrofit devices do not depend on legislation like upcoming EURO 7. Nevertheless, there is a need for public awareness, incentives, and policies to support the implementation of the filtration devices and for a market ramp-up. Moreover, the retrofit solutions should also contribute best possible to high innovation governance standards considering safety and overall sustainability along the entire life cycle of the products. The innovation project consists of pillars A) Development to bring existing retrofit technologies from TRL 4-7 to TRL 8 and B) Market preparation including sustainability assessment, public awareness, stakeholder engagement and proposal of incentive schemes.

We will present the overall project setup and scope of the Horizon Europe Innovation Action AeroSolfd. The status quo of the filtration devices will be described. The focus is on the development from TRL 4-7 to TRL 8 of the brake dust particle filter and the filtration solution for (semi-)closed environments. The ongoing developments as well as the methodology considered for the next steps will be presented. Preliminary results on how to assess the status quo of brake emission on city bus routes and about the passengers’ exposure at metro stations will be discussed in detail...

Learn More at FILTECH 2023 Conference - Register Now!

Clean air in cars: a method to test air cleaning systems in cars under real-life conditions using bacteriophages as virus surrogate

C. Hartl*, B. Führer, V. Sharp, C. Kirchnawy, G. Ettenberger-Bornberg, OFI Technology & Innovation Ltd, Austria; A. Löfvendahl, Volvo Car Corporation, Sweden

Since the emergence of the COVID-19 pandemic, transmission of viruses in indoor environment has become one of the major focuses of research. This is not only limited to hospital environments and other public facilities such as schools, but also means of transport ranging from high capacity public transport systems such as airplanes and trains down to individual transport methods such as cars have become areas of interest. Prolonged stays in closed environments can increase the risk of transmitting airborne biological particles, therefore appropriate ventilation and filtration of the indoor air is of high importance with various strategies and devices, such as air cleaners and HVAC being tested.

Currently, HVAC systems and air cleaners, as well as car ventilation systems and indoor cabin filters are primarily tested within laboratory conditions on filter test rigs or in enclosed test chambers using standardised plasticizer aerosols or mineral particles such as DEHS or smoke. The drawback to this approach is, while these test aerosols represent the bioaerosol particle size, they do not evaluate whether the filtration or cleaning mechanisms lead to significant inactivation of potential biohazards. With the focus on car cabin air cleaning, the aim was to develop a standardized method for testing car ventilation systems directly in cars under real-life conditions: on the one hand and carrying out said testing with phi6 bacteriophage bioaerosol, serving as virus surrogate, on the other hand to investigate actual decreases of viral activity within the enclosed car interior.

Learn More at FILTECH 2023 Conference - Register Now!

It`s a long way to clean air - If you wanna have zero emission cars

S. Schütz*, M. Schmidt, PALAS GmbH, Germany

Zero emission cars are one key to reach cleaner environment. However up to now it`s still a long way to reach that goal.

In the past the standards like the ISO 5011/ ISO TS 19713 for Engine Intake Filter to protect the engine and it`s performance, ISO 17536 for Crank Case Ventilation Filter to reduce the aerosol emissions, were very common in the automotive application, as well as the ISO 11155 Cabin Air Filtration for the protection of the passengers.

The Particle Measurement Programme or PMP is a programme for advancing the particle measurement technique for particulate vehicle exhaust gases. This was seen up to now the main driving for the car emissions, which lead us to the DPF filters in the automotive section. Recently the PMP test equipment shift their cut off size from 23 nm down to 10 nm.

In the automotive area there are several approaches in the past as well as upcoming guidelines to reach a zero-emission car.

Some approaches and research are nowadays done on the tyre abrasion, as well as on the brake emissions. The goal is to get a full footprint of the car emissions. The problem in that case is the output of fine dust as well as microplastic caused by abrasion of tyres and brakes. With the upcoming EU 7 standard the brake emission guideline GTR Proposal on Laboratory Measurement of Brake Emissions for Light-Duty Vehicles is on the way. Within the GTR Proposal the particle number counts as well as the PM 2.5 and PM 10 values are now in the focus. The solution is a brake dust emission filter which lead us closer to a zero-emission car and cleaner air.

Some zero emission cars are even available on horizon, like Prototype Zero Emission Drive Unit – Generation 1, the ZEDU-1. This car was developed by DLR (Deutsche Zentrum für Luft- und Raumfahrt) and the automotive company HWA. The ZEDU-1 was first introduced to public on the 28th of September 2022 on the Karlsplatz in Stuttgart, Germany.

There is still a long way to go until zero emission cars will be something normal. We like to show in this paper some solutions and measurement concepts to reach that goal...

Learn More at FILTECH 2023 Conference - Register Now!


L13 - Digitalization of Separation Processes

Day: 16 February 2023
Time: 13:00 - 14:15 h
Room 1

Session Chair:
Dr. Lars Spelter

Dewatering process: increasing productivity and embracing sustainability through digitalization

J. Bruzzo*, D. Otto, ROXIA Oy, Finland

Our world is now using resources at a speed that will be unsustainable in the future. Next generations would be at stake if changes introduced right now prove unsuccessful in reverting this negative trend. Words such as sustainability and circular economy are far more than catchphrases in large companies’ vision statements. They have indeed become disciplines where our trust is put as a guide to a better future in terms of conscious use of resources. We argue that the digital revolution is one fundamental enabler of implementing a proper sustainable operation. Industry 4.0 and digital transformation have given us the tools to democratize data and create accountability in our processes. Mining and, more specifically, dewatering activities are also the focus of digital transformation programs proclaimed by CEOs of leading mining companies. We at Roxia have dedicated the last seven years and a few million euros to adopting tools from Industry 4.0 to work in traditional and conservative companies devoted to the mining sector. As early adopters of IIoT and analytics in industrial processes, we have had the opportunity of developing and witnessing cases where sustainability has become a decisive driving factor in dewatering operations using our cloud analytics platform Malibu®. In this paper, we will share the insights and results of successful applications in digitalization, data analytics, and the application of artificial intelligence to solid-liquid separation...

Learn More at FILTECH 2023 Conference - Register Now!

Potentials of digitalization in the direct recycling of Li-ion battery materials via centrifugation

T. Sinn*, M. Gleiß*, H. Nirschl, Karlsruhe Institute of Technology (KIT), Germany

The process industry is currently undergoing various changes, to a large extent induced by the growing request for more resource-efficient production and product cycles and motivated by a range of economic and ecological reasons. Thereby, the focus lies not only on installing new plants for novel processes, but also on optimal operation of existing production plants, enabling optimal exploitation of energy and materials. However, when processes are very complex, conventional practices are often not suitable to operate the process satisfactorily close to the optimum. The same challenge arises when specific product properties are demanded, but the process behavior or feed properties change during operation. Accurate setting of operational parameters is required, which must be realized through a sensible control strategy. In such complex cases, a model-based control is a potentially sound solution.

At the same time, mobility is about to undergo a fundamental transformation towards electric vehicles. This will certainly entail a growing demand for materials needed in batteries (Li, Mn, Co for example) as well as increase the urgency to develop recycling processes for end-of-life batteries. There are recycling approaches, but further development is necessary to achieve thoroughly safe, efficient, and profitable processes for environment, economy and functionality of recyclate-based batteries.

The presented investigation concentrates on centrifugation as a potential step in a battery recycling process chain. The well-known unit operation is examined as the key step – separation of electrode constituents for further selective treatment – in a newly developed direct recycling approach for Li-ion batteries...

Learn More at FILTECH 2023 Conference - Register Now!

Multiscale modelling and simulation of coolant particle filters and ion exchangers in electric mobility

R. Kirsch, S. Osterroth*, Fraunhofer Institute for Industrial Mathematics (ITWM), Germany

For both fuel cells and battery systems, the components of the cooling system are essential to maintain an economic usage and to ensure the desired lifetime of propulsion technologies in electric mobility. For this purpose, mostly a water-glycol mixture is used. Due to the huge amount of heat generated by those devices, a high flow rate inside the cooling loop is required. However, also the coolant has to satisfy several requirements:

  • The electrical conductivity of the coolant has to be kept low to avoid electrical shorts. Different parts of the coolant loop such as the pump, the fittings or heat exchangers can slowly release ions into the coolant [1, 2]. Possible mechanisms for the release might be leaching, degradation, or corrosion [3].
  • Contaminants in the coolant can disturb the cooling process itself (e.g. blocking of channels in the heat exchanger) and, as in other filtration processes, increase the pressure drop. Due to a decreased cooling power, this might lead to an increase in temperature and thus to a reduction of the lifetime and performance of the fuel cell or battery systems [2].

For the removal of ions, mostly a resin consisting of microporous spherical beads is considered. Since both anions and cations might be present, a mixed or layered configuration of specific resins for anions and cations is used. The release of ions is greatest at the beginning of the process and usually decreases with time [2]. Moreover, the concentration of ions depends on viscosity (temperature) [1]. Therefore, the resin should ensure a specific capacity. Nevertheless, the resin can be exhausted over time and it is important to replace the ion exchanger before the electrical conductivity of the coolant exceeds a given limit. Furthermore, the pressure drop caused by this component of the cooling loop should be as low as possible.

The coolant particle filter medium should allow for a high flow rate with a low pressure drop. Therefore, woven media (screen meshes) are well suited, since they provide a sharp cut-off diameter to ensure that particles bigger than a given diameter cannot enter the cooling channels [2]. By an increase of the weave area, the pressure drop can be decreased.

In this work, models and simulations for different components of the cooling system are presented. The resin of the ion exchanger is modelled using a multiscale approach...

Learn More at FILTECH 2023 Conference - Register Now!


M06 - Separation of Complex Systems

Day: 16 February 2023
Time: 13:00 - 14:15 h
Room 4

Session Chair:
Dr. Christine Sun

Enrichment of biofunctional proteins from acid whey by membrane filtration

F. Ostertag*, J. Hinrichs, University of Hohenheim, Germany

Cross-flow filtration is a well-established unit operation in the dairy sector. The common fields of application cover a broad spectrum of membrane types, ranging from microfiltration (e.g. fractionation of whey and casein proteins), up to nanofiltration (e.g. concentration and fractionation of sugar) and reverse osmosis (e.g. waste-water treatment). Furthermore, ultrafiltration is commonly used for the production of whey protein concentrates (WPC) and isolates (WPI). However, the largest market share of whey protein originates from sweet or native whey, offering an appropriate valorization potential of this highly abundant by-product (estimated worldwide cheese whey production1): > 200 million t/a)

Conversely, the utilization of acid whey is difficult due to its increased lactic acid and mineral content. At the current time, large efforts are made to find economically and environmentally sustainable applications for this underutilized by-product. The growing demand for fermented high-protein dairy products (e.g. Greek yogurt) strengthens the necessity for innovative valorization strategies. Acid whey is often used as animal feed, organic fertilizer, or as a substrate for biogas production. These approaches might allow cost-neutral disposals, but they ignore the valorization potential that arises from the unique composition of the whey protein fraction. Besides the major whey proteins β-lactoglobulin and α-lactalbumin, numerous biological active minor whey proteins such as immunoglobulins, lactoferrin, growth factors, lactoperoxidase, and further valuable enzymes can be found in whey. Acid whey is a ubiquitous and inexpensive source for exploiting and isolating these high-value proteins. Since the native protein concentration in whey is low (c = 5 mg/mL – 8 mg/mL), filtration technology is a central key for any further valorization step. To find optimal process conditions...

Learn More at FILTECH 2023 Conference - Register Now!

Unlocking the potential of integrated process solutions: The role of membrane technology

J. André,* Koch Separation Solutions, Germany

Membrane Technology is a well-known and established technology with process engineering. Whether for purifying streams, removal of impurities or in more complex approaches such as in component fractionation, most membrane-based separation steps are based on these approaches. Most of the times, however, membrane steps are approached individually, taking only stream inputs and desired outputs to design them. This presentation will present several situations within Koch Separation Solutions (KSS) where membrane processes are used to intensify an overall process, either by debottlenecking an existing process, increasing process efficiency or reduce its environmental footprint.

During the presentation, different processes will be introduced and described. The first case will describe the debottlenecking of an evaporation step for a yeast production operation. The KSS customer needed to expand operations and the limiting step was the evaporation step which was at its maximum capacity and without available space to add a new evaporation unit. Working together with the customer, KSS developed a membrane process that resulted in not only permitting the increased production expansion but allowed for extra capacity still being available if the need arises.

The second case was developed for a large dairy customer. KSS is presently delivering a complete processing line for the production of different dairy products using membrane technology, evaporation, spray drying and solids handling. For this KSS created a design including integrated membrane steps which not simply further the separation process but also feed back on each other to intensify it.

Lastly, the new Li-PRO™ process for Lithium extraction from brines will be presented. In this process, membrane technology is used together with adsorption, ion-exchange and thermal separations to reach up to 99% extraction efficiency for Lithium while minimizing water and resource consumption. In the process, water is reused to the maximum possible and other solutions, such as NaCl reuse in regeneration processes, are considered. The design also allows for energy optimization to allow for resource availability of production sites.

During the presentation, an overview of the case studies will be provided, with some attention to the development and design process and especially to the integration of different steps or unit operations...

Learn More at FILTECH 2023 Conference - Register Now!

Elaboration of a specific polymer inclusion membrane for the processes of total selective separation and recovery of methylene blue and direct red 80 dyes from contaminated aqueous solutions

I. Mourtah, I. Mechnou, Y. Chaouqi, N. Sefiani, M. Hlaïbi*, University Hassan II, Morocco; L. Lebrun, University of Rouen, France

In the last few years, membrane technologies have experienced a considerable growth, due to their numerous uses and their advantages over other conventional techniques. The membrane processes present today an important research topic, especially affinity polymer membranes, very adapted to oriented processes. Methylene blue is one of the most widely used dyes in various fields such as chemistry, medicine, dentistry and the dye industry. Our objective is to develop a polymeric inclusion membrane for methylene blue extraction and recovery processes, assisted by activated carbon. We developed a membrane based on a mixed polymer support, polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP), and the amphiphilic molecule Tween 20 (TW20) as extractive agent (EA). In order to quantify the performance of developed membrane, macroscopic parameters....

Learn More at FILTECH 2023 Conference - Register Now!


F07 - Progress in Electrospinning

Day: 16 February 2023
Time: 14:45 - 16:00 h
Room 3

Session Chair:
Dr. Christine Sun

Defeating defects: new innovations in free-surface electrospinning

J. Manasco*, Elmarco, s.r.o., Czech Republic

Elmarco is the global leader in industrial electrospinning equipment and solutions. We create value for our customers by providing the best industrial nanofiber production equipment and solutions that matches our customer’s needs.

Many of our customers are interested in membrane applications such as liquid filtration, performance apparel and battery separators. It is well understood that these applications can benefit from the use of electrospun membranes vs. conventional membranes due to the ability to achieve higher flux (or flow rates) at the same rejection efficiencies. These higher flux and higher performance membranes will reduce energy consumption and process costs.

One of the biggest advantages of the electrospinning process is that there are many variables (process inputs and process settings) that can be used to tune the nanofiber layer properties. However, despite controlling these variables, a major hurdle in reliable, industrial membrane production using electrospinning, is defect generation. For the aforementioned applications, any significant defect and/or pinholes in the membrane, whether electrospun or conventional, has always created a challenge due to the stringent material performance requirements. Elmarco has taken our significant knowledge and experience with our existing free-surface electrospinning technology (LINEA line) and created a new generation of equipment (INFINITY line) technology which maintains the industrial, high-throughput, and scalable aspects of our existing equipment along with the industry leading ability to virtually eliminate significant membrane defects from these membranes.

In this paper, we will demonstrate through filtration performance, hydrostatic head, and porometry, the impact of defects and the ability for our newest innovation to produce nanofiber membranes that are devoid (free) of significant defects. Moreover, we have developed a membrane visual scanning technology that can continuously quantify and track defects throughout the membrane production process. This material quality information provides confidence to our customers that the material can be properly processed downstream and will ultimately result in the final product with the necessary performance specifications and most importantly, without critical defects.

Learn More at FILTECH 2023 Conference - Register Now!

Electrospinning of polyurethane nanofibers with non-toxic solvents and production of hybrid filter media

J. Liedtke*, R. Weygandt, C. Mehring, University of Stuttgart, Germany

Conventional air filter media show a characteristic local minimum in particle separation efficiency in the size-range of 100-500 nanometres, commonly known as the most penetrating particle size (MPPS). New filter media are being developed to achieve high separation efficiencies across the entire particle-size range while minimizing the pressure drop of the particle-laden gas flow across the media. The use of nanofibers has proven to be particularly successful in this context, since on the one hand the desired high separation efficiency in the MPPS range can be achieved while on the other hand the pressure loss is significantly reduced compared to similarly efficient filter media consisting of traditional fibers in the micrometre range. Since filter media consisting solely of nanofibers also have disadvantages, such as a lack of stability, the advantages of micro- and nanofibers are often combined in so-called hybrid media.

In this work two-layered hybrid filter media will be produced consisting of an industrially manufactured filter media coated with polyurethane nanofibers. The main focus here is on the production and simultaneous deposition of the polyurethane nanofibers onto the prescribed filter medium using single-needle electrospinning, without additional coating or fixation process. Potential solvents for dissolving polyurethane include dimethylformamide (DMF), dimethylsulfoxide (DMSO), tetrahydrofuran (THF) and acetone (AC). Numerous publications describe dimethylformamide or a mixture of tetrahydrofuran and dimethylformamide as a suitable solvent system; however, dimethylformamide is on the candidate list of substances of very high concern (SVHC) according to Regulation (EG) Nr. 1907/2006 (REACH), i.e. substances that may have serious effects on health and the environment. For this reason, DMF should no longer be used for the production of polyurethane nanofibers and an alternative non-toxic solvent or solvent combination has to be found. Unfortunately, there is hardly any work to be found in open literature that deals with the production of polyurethane nanofibers using non-toxic solvents.

In the course of this work, the non-toxic solvent combination AC/DMSO has proven to be a particularly suitable candidate. During electrospinning...

Learn More at FILTECH 2023 Conference - Register Now!

Electrospun recycled poly(ethylene terephthalate) (PET) nanofiber for application in air filters

G. B. Medeiros*, M.L. Aguiar, D. S. de Almeida, Federal University of São Carlos, Brazil

Atmospheric pollutants can present in their composition respirable particulate matter, toxic gases, and pollutants. For this reason, serious diseases such as respiratory, cardiovascular, and even neurological diseases are of high risk to human health. Aiming to improve the equipment high performance used in the gas filtration and in the particulate matter removal, new filter media are being developed Thus, the main objective of this work was the production of high-performance filter media in the ultrafine particles air filtration with low energy consumption. Filter media are recyclable from usable poly(ethylene terephthalate) (PET) using an electrospinning technique. Electrospinning is considered one of the fiber production most versatile methods today, in addition to being the only method for large-scale continuous nanofiber production. This technique consists of applying an electric field, a high voltage, between the needle tip and a metallic collector. The electric field acts on the polymeric solution drop that leaves the needle tip. The drop is deformed and the electrospun jet travel the path to the collectors, where micro and nanoscale fibers are deposited. In the present work, three PET concentrations...

Learn More at FILTECH 2023 Conference - Register Now!


G15 - Automotive Applications II

Day: 16 February 2023
Time: 14:45 - 16:00 h
Room 2

Session Chair:
Dr. Jörg Meyer

Highly efficient nanofilter system for large scale petrol engine retrofit, core part of the EU Horizon Project AeroSolfd

A. Mayer, J. Czerwinski, T. Lutz, L. Rubino*, L. Larsen, VERT Association, D. Engelmann, University of Applied Sciences Biel, Switzerland; V. Hensel, AURIGNA; M. Lehmann, Mann+Hummel GmbH; J. Dumno, CORNING GmbH, Germany

Reduction of particle emissions from the mobile sector has worldwide focussed on diesel engines. Limit values have been introduced from 1982 and today the diesel particle filter DPF is a standard component for HD and LD vehicles as well as for offroad machines. Petrol engines however have never been controlled for particle emissions, nowhere on the globe until 2017 when new DI petrol engines received a PN limit value, still higher than diesels. The simple reason was, that diesels can and sometimes do smoke and petrol engines have a non-smoky transparent exhaust gas.

Research however knows that petrol exhaust is only transparent because petrol particles are smaller than diesel particles an thus invisible. Research also knows that smaller particles are easily penetrating alveoli membranes and thus effect health stronger. These small particles may even be smaller than size cut-off of actual EU-particle metrology thus they may not even be detected today. On the other side we have to take note that worldwide vehicle fleets contain many more petrol engines than diesel engines and since new research has revealed that particle number concentration of petrol engines can be orders of magnitude higher than with diesels, we have to worry about a carcinogenic pollution effect which today is not recognized by emission statistics, not even in the USA and Europe, a hidden health thread, maybe the largest.

A technology is needed, which must be flexible enough to also be applied to in-use vehicles and the EU looks for a technical demonstration proving that this technology can be made available within three years at reasonable implementation cost. Within the AeroSolfd project we will therfore investigate a statistic sample of 1000 vehicles for ultrafine particle emissions in order to get a feeling about the size and urgency of this problem and we will retrofit 50 vehicles of different brands in three different countries. We also would like to think outside the box based on fleet analysis in Mexico city where VERT has analysed 400‘000 vehicles with shocking results with respect to the high emitter effects.

But do we have the technology? DPF cannot just be applied to petrol engines like to diesels, since DPF only filter efficiently after a soot layer has been build up on the ceramic filter wall since the average pore size of the ceramic wall is around 10 μm and the diesel particle might be as small as 100 nm. Petrol engines however do not build up this filtering soot layer, so a petrol engine with a DPF may only filter < 70% which is by far not good enough.

Quite recently new pore structure technologies have been developed, called membrane technology or hierarchic pore structure technology, which promise much better results. These technologies have been already pre-tested and demonstrated particle filtration in the size range of 10 nm – 500 nm of over 99% even with the brand new filter or fully regenerated.

Another problem must be solved to detoxify exhaust gas of petrol engines, which is the high concentration of PAH coated on these particles which might become desorbed even between regeneration phases which requires an additional catalytic activity to be included in this system.

The paper will present the best available technology for this project and first results with different GPF with respect to size specific filtration and toxic gaseous emissions.

Learn More at FILTECH 2023 Conference - Register Now!

Energy-efficient separation of nanoparticles through electrification of air filtration

L. Petersen*, A. Lawson, J. Niehoff, Hengst SE, Germany

Air pollution is one of the biggest health risks worldwide. The toxicity of particulate substances depends on quantity, particle size as well as chemical composition. The smaller the particle size the deeper particles can penetrate the human body. Particles with a size smaller than 0.1 µm can enter the lung tissue and then the bloodstream. As a result, these particles can cause not only acute and chronic lung diseases, but also cardiovascular diseases. In addition to classical organic and inorganic pollutants, the recent COVID pandemic has increased concern and understanding of the impact of micro-organisms and bacteria in the atmosphere. Consequently, awareness regarding air pollution and its consequences is increasing worldwide. The level of fine dust increases with higher traffic volume with increasing levels of particles entering the cabin of the car. State-of-the-art cabin air filters consist of different filter layers. In many systems, the particle filter layer is a so-called electret filter medium. Such filter media offer an acceptable initial retention at a relatively low differential pressure. However, during the lifetime of the element, the filtration efficiency decreases dramatically. The efficiency in the microscale particle size range can drop under 10 %. Consequently, different car manufacturers have introduced solutions that rely more on mechanical rather than electrostatic filtration. Since the permeability of those media is much lower the required filter size can be–depending on the targeted efficiency level –up to 10 times compared to state-of-the-art cabin air filters. Alternatively, utilizing those media in existing small package the pressure drop and consequently the energy demand of the system increases by a similar order. Hengst Filtration has developed an innovative filtration solution that achieves high filtration efficiency on compact space at a low pressure drop. This is achieved through electrification of the system using a combination of ionization and polarization. Ionization provides the particles with a very high level of electrostatic charge making them more likely to be captured in an electret filter medium. Polarization of the filter element leads to a conservation of the charge distribution within the filter medium. Therefore, the high initial filtration efficiency can be conserved over filter lifetime.

In the presentation, the effects of ionization and polarization alone as well as in interaction are presented. The filtration performance of the electrified filter system under various conditions will be discussed...

Learn More at FILTECH 2023 Conference - Register Now!

The co-relation between actual vehicle performance and Laboratory test results of 3Wheeler air filter

P.M. Gade, G.G. Garkhedkar, S.M. Chakote, R. More, Varroc Polymers Ltd, India; H. Sauter*, Consultant, Germany

The research work presented here is related to 3wheeler Autorickshaw actual vehicle air filter performance comparison with testing laboratory results. These vehicles are used in India for commuting between cities, towns and near by villages by the urban and rural village men and women.

Since these vehicles are used very frequently, day and night by the country men, it is necessary to take care of their health, air pollution and reduction of emission of toxics gases, etc. Hence it is necessary to have highly efficient air intake system in engine.

The comparison of laboratory results which were tested according to ISO5011 standard of air filters, indicates that the actual conditions were very much safer with respect to above parameters. This study was done for air filter testing before fitting on vehicle and after vehicle running for 20,000 kilometres. The pressure drops, initial and full life efficiencies and element dust holding capacities were studied. This study helped to predict better mileages and air filter element service life increased by 65%. Another objective of this study was to understand the difference between laboratory test results and actual performance as actual tests are not possible to conduct every time as they are time consuming and not feasible due to various real-life conditions...

Learn More at FILTECH 2023 Conference - Register Now!


L14 - Oil/Water- and Oil/Solid-Separation

Day: 16 February 2023
Time: 14:45 - 16:00 h
Room 1

Session Chair:
Dr. Harald Anlauf

Enhancing filtration performances of wet-laid synthetic nonwovens thanks to improved structures and digital product development

C. Prost, E. Ruiz*, A. Corradi, O. Soikkeli, Ahlstrom-Munksjö, France/Italy/Finland; P. Eichheimer, M. Azimian, Math2Market GmbH, Germany

Trinitex® is an A-M proprietary and patented wet-laid nonwoven technology leading to unique three-layer filtration media. This technology allows indeed the simultaneous formation of three layers in one step with the possibility to use different types of synthetic and natural fibers as well as granular activated carbon and microglass fibers. Since early 2000’s, Trinitex® has been chosen as a Premium Air and Liquid Filtration solution.

Trinitex®, from A-B-A structure to A-B-C structure

Traditionally, the structure of Trinitex® nonwovens is an A-B-A type of structure with hour-glass gradient where A layers typically have same fiber mix whereas B layer typically has a different fiber mix. Ahlstrom now has the enhanced capability to commercially supply filtration media with A-B-C structure where all layers A, B and C have different fiber mix as well as different basis weights. This enhanced capability opened up new horizons towards more flexible Trinitex® product designs going together with increased dust holding capacities and longer filter lifetime...

Learn More at FILTECH 2023 Conference - Register Now!

Bioinspired oil/water separation with superhydrophobic textiles

L. Beek*, M. Akdere, T. Gries, RWTH Aachen University; P. Ditsche, M. Mail, W. Barthlott; University of Bonn; K. Klopp, Heimbach GmbH, Germany

Despite the expansion of renewable raw materials and alternative energy sources, global consumption of oil amounted to approx. 14.07 million litres per day in 2020. Oil is thus the most widely used energy source worldwide, accounting for 31.2 %. [1]

During the extraction and transport of oil, accidents occur, causing severe and sometimes irreversible pollution of the environment. Not only major accidents such as the spill of 21,000 litres of diesel in Siberia in 2020 are relevant, but also smaller oil accidents such as overturned oil tanks during floods.

State of the art methods for oil removal have the disadvantages of being mostly very slow, having secondary toxic effects on humans and marine environment or generating additional hazardous waste.

In this study, a new textile inspired by superhydrophobic biological surfaces is presented. These surfaces adsorb oil through their hierarchical structure while separating it from water [2]. Since such plants cannot simply be transported into oil-polluted waters, the active principle was abstracted and transferred to a technical textile. This allows the oil to be adsorbed, simultaneously separated from the water and transported into a container....

Learn More at FILTECH 2023 Conference - Register Now!


M07 - Membrane Fouling

Day: 16 February 2023
Time: 14:45 - 16:00 h
Room 4

Session Chair:
Dr. Qian Zhang

Promoting fouling reversibility via introduction of sodium dodecyl sulfate prior to ultrafiltration of produced water in polishing step

H. Idrees*, I.M.A. ElSherbiny, S. Panglisch, University Duisburg-Essen (UDE), Germany

Tremendous portions of oily wastewater (known as produced water) are released daily from different oil industries that must be properly treated before discharging into surrounding environment or reusing. Nowadays, the potential of produced water reusing is gaining an increased attention. Pressure-driven membrane-based separation is emphasized as promising technology due to high water recovery, simplicity, small footprint and ease to be integrated into already-established treatment plants1-3. Nevertheless, high fouling propensity of polymeric membranes is a major challenge facing membrane-based treatment of emulsified oil feeds 4-6. Accordingly to Tummons et al.4, about 80 % of studies in the field were carried out at constant pressure, while only ~ 8 % employed constant flux condition. Nevertheless, constant flux operation is substantially dominating membrane-based treatment plant. Moreover, about 70 % of the studies were performed in crossflow mode, whereas dead-end operation was rather limited to fouling layer characterization purposes4. Crossflow is known to be associated with higher investment and operation costs in comparison with dead-end operation.

In the current study, sodium dodecyl sulfate (SDS) was introduced to promote the performance of polyether sulfone (PES) hollow-fiber membranes in mini-plant dead-end ultrafiltration of model oil feed water. This novel approach is targeted as a polishing step in the treatment of oily wastewater effluents (i.e., produced water after primary and secondary treatment stages), where oil concentration is in range of 20 - 100 mg/L, and the average oil droplet size is commonly below 1 µm7, 8...

Learn More at FILTECH 2023 Conference - Register Now!

Application of a hydrogen peroxide based cleaning strategy for ultrafiltration processes to protect the aquatic environment

M. Werner*, L. Matthies, MANN+HUMMEL Water and Fluid Solutions, A. Bauer, A. Merz, S. Krause, Hochschule Darmstadt, University of Applied Sciences, Germany

The demand for membrane based waste water treatment processes, such as membrane bioreactor (MBR) and processes to further purify wastewater e.g. ultrafiltration (UF) combined with activated carbon or ozone, is continuously growing in recent years due to higher effluent quality requirements of waste water treatment plants (WWTP) and reuse purposes. During operation of UF membranes or MBR plants, membrane surfaces tend to be fouled with organic material and inorganic deposits. If not controlled adequately by applying mechanical and chemical cleanings, a layer on the membrane surface is built up continuously, which results in a decline of membrane performance (e.g. loss of membrane permeability). To maintain the operation within an optimal range of operation, chemical cleanings have to be performed.

Typically a distinction between two types of chemical cleanings is made: weekly scheduled maintenance cleaning (MC) and a semi-annually to annually performed recovery cleaning (RC). Both types of cleaning procedures include different chemical agents due to the purpose of the cleaning. To remove inorganic fouling (scaling), citric acid is induced and for the removal of biofouling sodium hypochlorite (NaOCl) is commonly applied at municipal WWTPs. The main benefits of NaOCl are the cost-effectiveness and the ease of use. Nevertheless, by using NaOCl several disadvantages e.g. the inevitable generation of toxic halogenated by-products, e.g. adsorbable organic halides (AOX) must be considered. The presence of AOX can cause damage to human health and environment [1]. Apart from this, frequently applied chemical cleanings with high NaOCl target concentration can shorten the membrane lifetime [2]. Therefore, the demand for alternatives increases continuously. Such an alternative cleaning agent is...

Learn More at FILTECH 2023 Conference - Register Now!

New PAN-g-PEO ultrafiltration membrane: Filtration and anti-fouling performance with complex water composed of water/oil/particles

E.H.I. Ndiaye*, H. Nabet, J.-M. Pereuilh, S. Dehez, TotalEnergies; J.-M. Pandraud, Clean Membranes; J.M. Espenan, Polymem; N. Abidin, ABC Membranes, France

Producing oil or gas generates a large quantity of produced water, which is extracted with the hydrocarbons, especially for mature fields. Thus, the management of produced water is a critical challenge for operators. Produced water can be successfully reused for pressure support or safely discharged into the environment. To do so, it is necessary to efficiently remove hydrocarbons and suspended solids. Separation processes using membrane technology have been developed to meet these challenges, but capital cost (mainly for offshore installations) and operability (fouling) remain crucial challenges.

It is well known that polyacrylonitrile (PAN) membranes have good hydrophilicity and chemical stability, but the utilization of PAN in hollow-fiber membranes has only met limited success with hydrocarbons. However, Clean Membranes developed a novel variation of the PAN polymer by grafting it with PEO to form a proprietary amphiphilic comb copolymer, polyacrylonitrile-graft-poly (ethylene oxide) (PAN-g-PEO). Hollow fiber membranes made with PAN-g-PEO were demonstrated by Clean Membranes to have good capabilities for separating hydrocarbons from produced water without fouling, but these early membranes lacked sufficient mechanical strength for commercial applications. Clean Membranes subsequently collaborated with ABC Membranes and Polymem to develop and manufacture a novel in-out, multi-bore PAN-g-PEO UF membrane named PANFLUTE. Laboratory studies conducted by ABC Membranes using their proprietary PANFLUTE structural membrane design demonstrated good filtration performance in terms of wettability, permeability, and resistance to irreversible fouling with complex water composed of water/oil/particles.

Following ABC Membranes’ laboratory studies, it was decided to test the process for the treatment of oily water with PANFLUTE. utilizing their test platforms and conducting the tests under their control. Clean Membranes, ABC Membranes, and Polymem teamed with TotalEnergies to conduct this testing. In 2022, qualification tests were carried out by TotalEnergies at its R&D platform (PERL) based in Lacq (FRANCE) to qualify the PANFLUTE membrane and confirm the performance on the treatment of produced water while limiting the use of chemicals through the implementation of an advanced maintenance method that does not require the use of chemicals during backwashes. The pilot study shows promising...

Learn More at FILTECH 2023 Conference - Register Now!

Nothing found.

Make your FILTECH visit easy and effective ! Choose papers of your interest.

0 / 25 selected

Complete Conference Programme (PDF)