Plenary & Keynote Lectures 2022
Roaring twenties in air filtration – Driving for a cleaner world
Dr.-Ing. Martin Lehmann
Principal Expert Research Network and Public Funding – MANN+HUMMEL / Germany
In medias res: Air filtration is omnipresent for delivering clean air: protecting engine and equipment known as engine filtration, enabling processes and technology known as industrial filtration, providing comfort and indoor air quality known as HVAC filtration or prominent as indoor air purifier for reducing risk of aerosols in closed environment. Adding gas adsorption, the domain of cabin air filtration shows up. The focus in this talk will be on particle filtration.
Tempora mutantur et nos mutamur in illis. A bit more than twenty year ago, the digital revolution in air filtration started. First realistic simulations of particle collection on single fibers. First time visualization of the 3D microstructure of a fibrous filter. CFD and FEA have become a key tool for designing air filter systems. Nowadays, we are starting to use AI-based simulation tools for designing air filter elements. In addition, in the past twenty years the design of the filter elements changed significantly. There is no longer a set of just rectangular or round filter elements. With evolving production technology, we are now thinking and designing in flexible element shapes with concave curvature, oval outline, or variable pleat heights. Customers have become used to filter elements fitting just right into their complex 3D design space.
Quo vadis air filtration? Our decade of the 2020s is a quite prosperous and important time for air filtration. The production of new internal combustion cars is still growing (until the end of 2020s), the vehicle in operations will further grow, and filtration for heavy duty and industrial equipment will continue to be in demand. But it is also a time to redefine air filtration: new air filtration products will be needed, even for e-mobility. Focusing on reducing emissions adds the need for innovative filtration solutions, such as brake dust filtration, but also demands some kind of an altruistic, community-centered approach: With my frond-end air filter, I contribute to lower fine dust emissions while driving!
The plenary lecture will be a personal collection of examples illustrating the evolution of air filtration in the approximately last twenty years as well as an outlook into the roaring 2020s in air filtration.
Dr.-Ing. Martin J. Lehmann is Principal Expert Research Network and Public Funding at MANN+HUMMEL. Before he served four years as Vice President Air Filtration and Engineering Air Filter Elements at MANN+HUMMEL GmbH. In this assignment Dr. Lehmann has been responsible for the strategic orientation of air filtration as well as for the global R&D of air filter elements in the transportation segment. From 1998 until 2003, he worked in Prof. Kasper’s research group at University Karlsruhe and earned his doctoral degree in 2005 on modeling loading kinetics and 3D MRI visualization of single fibers in air filters. In 2004, Martin Lehmann joined Cummins Filtration at Stoughton, Wisc. From 2006 until 2016, he advanced and set milestones with his simulation team for filtration at MANN+HUMMEL, Ludwigsburg, regarding simulation of filter media and elements. Dr. Lehmann is a member of the Scientific Committee of the FILTECH, the American Filtration and Separation Society, WFC13. He is appointed member of the Scientific Advisory Board of the GSaME at Uni Stuttgart and elected board member of the AFS (2020-2022). He was co-chair of several AFS conferences and is co-chairing the 2021 AFS conference. Dr. Lehmann was an invited keynote speaker at InterPore, AFS and FILTECH and has published over 80 technical papers.
Simulation of solid-liquid separation processes: Challenges in modeling and experimental validation
Prof. Dr.-Ing. Sergiy Antonyuk
Institute of Particle Process Engineering, Technical University of Kaiserslautern / Germany
With the rapid increase in computing power, numerical simulation is becoming increasingly important for the prediction and description of solid-liquid separation processes. Numerical studies can improve knowledge of complex separation mechanisms and support the model-based optimization of existing and the development of novel separation processes.
The approaches used for the modeling and simulation of solid-liquid flow processes differ in the resolution of the flow and boundary layer, consideration of physical effects, microprocesses and interactions as well as the computational effort. This contribution gives an overview of the different approaches and demonstrates their suitability and challenges for the description of the transport and separation of fine particles by comparing simulations with measurements.
The focus is on the detailed description of the separation of particles from suspensions in complex nonwoven structures or in a filter cake by taking into account micromechanisms and real filter medium microstructure. The particle-particle, particle-fibre and particle-fluid interactions, formation and breakage of aggregates, clogging of pores and the compressibility of particles in the filter cake can show a major influence on the filtration process. For the description of these microprocesses, the particle separation can be simulated with the coupled Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD). The contacts between particles and fibres are calculated numerically by DEM with force and angular momentum balances, where contact deformation and adhesion as well as drag and viscous forces due to flow obtained with CFD are considered. The kinematics and dynamics of each individual particle and the entire particle collective in the suspension can be obtained. In contrast to other methods, DEM is able to consider such effects as particle size distribution and irregular shape, plastic deformation, friction, rotation, sticking of particles and breakage of agglomerates. The real microstructure of the filter medium can be obtained by computed microtomography and implemented in a 3D model for simulation of particle deposition.
The recent applications of DEM-CFD methods in the field of filtration are presented. The measurement methods for the parameter estimation (mechanical particle properties, friction, restitution coefficient, adhesion) and validation of the DEM-CFD model will be explained with examples of experiments.
Prof. Sergiy Antonyuk is full professor and director of the Institute of Particle Technology at the Technical University of Kaiserslautern, Germany. He studied Process Equipment and Engineering at the Donetsk National Technical University in Ukraine. In 2004 he obtained his first PhD in ecological safety at the National Technical University Kyiv. In 2006 he received his second PhD in Process Engineering at the University of Magdeburg (Germany) and continued his research in particle technology during postdoctoral period in the group of Prof. Jürgen Tomas. In 2008 he moved to Hamburg University of Technology to work as Assistant Professor in the Institute of Solids Process Engineering and Particle Technology (Prof. Stefan Heinrich). Since 2014 he is full professor at the TU Kaiserslautern. His research covers filtration and separation processes in the liquid and air, contact mechanics and breakage dynamics of the particles and agglomerates, flow behavior of powders, surface functionalization, and simulation of multiphase flow using Discrete Element Method, Computational Fluid Dynamics and other numerical methods.
Membrane filtration and sustainable development
Prof. Dr. Pierre-Yves Pontalier
ENSIACET LCA Laboratoire de Chimie Agro-industrielle / France
Membrane processes are used in a very large number of industrial fields such as the food industry, the chemistry, the pharmaceuticals or the environment. Membrane processes contribute to the protection of the environment as they allow the depollution of industrial and urban effluents. They may also help to limit environmental degradation by integrating new cleaner processes, particularly those related to the biorefinery concept. This concept, which aims at the multivalorization of plant and animal resources, is a perfect example of the integration of membrane processes in this approach. For example, in the context of the valorization of lignocellulosic biomasses, the purification of hemicelluloses and lignins is carried out through a membrane filtration stage. Similarly, the valorization of proteins contained in wheat bran or rapeseed cake passes through an ultrafiltration stage. Another pathway that is developing is the fractionation of microalgae, called algo-refining, in which membrane processes are involved in the purification of polysaccharides and proteins.
In the case of drinking water production or industrial effluent treatment, very large membrane surfaces are used, with a lifetime of a few years. Thus, membrane processes become a very important source of pollution. The life cycle analysis of membrane processes thus shows that their impact is not negligible. Two types of impacts are generally highlighted, those related to the production of the membranes (e.g., the use of petro-sourced materials) and those related to the operation of the processes (e.g., the energy used and the chemicals during the cleaning phase). One environmental impact that is neglected is the end-of-life impact of the membranes, the fate of which poses problems. Studies are beginning to appear to evaluate methods of reusing used membranes in order to increase their lifespan, but this does not solve the problem of the end-of-life of the materials. Within the framework of sustainable development, it would be desirable to produce membranes from bio-sourced molecules and above all to facilitate their destruction.
Pierre-Yves Pontalier has a scientific background in food engineering. He obtained a PhD on the modeling of the nanofiltration separation mechanisms, applied to whey fractionation. He has been a Professor in Process Engineering at the Institut National Polytechnique de Toulouse since 1998. He has been working for 30 years in the field of separation processes, with a particular focus on liquid/solid separation membrane and chromatographic processes. He is the author of 50 peer-reviewed papers, 3 patents and 4 book chapters in the field of liquid/solid separation. He has been a member of French Society in Fluid Solid Separation (SF2P) since 2010 and chair since 2019. He participates to the organization of FPS and FrancoFilt congresses..
Closing the gaps: How can we stop microplastics pollution?
Dr. Katrin Schuhen
Wasser 3.0 gGmbH / Germany
Due to the fact, that microplastics are a global environmental problem, clarity about microplastics pollution, its entry path and distribution, its behavior in ecosystem and influence on human life is important to setting political restrictions and promoting efficient reduction strategies.
During the last two decades, the scientific community started their intensive work in different fields of microplastic research. An overview of the current state of knowledge about microplastics pollution will be given. Additionally, fields of application in which the removal of microplastics from waters is necessary or useful will be presented as well as technological solutions.