Associating filters by series for optimizing the retention capacity of nanoparticles

A. Charvet*, S. Pacault, D. Thomas, Lorraine University, France

At this time, because of their very high-efficiency, the fibrous filters are the most commonly dedusting systems used for individual and collective protection. High efficiency particulate air (HEPA) filters are used in many applications: containment in medical, pharmaceutical or nuclear facilities, cabin air treatment in automobiles and aircrafts, vacuum and so on. In addition to their high efficiency, these filters, usually non regenerable, may have an important lifetime (i.e. high dust retention capacity) to avoid too frequent replacements.

In the specific case of nanoparticle filtration, the morphology and the size of these particles induce, for the same area density of collected particles, a faster increase of the pressure drop during the filter clogging than for submicronic and micronic particles. This further reduces the lifetime of the fibrous filter and makes even more important the optimization of its retention capacity.

To further improve the filter performances, a possible solution is to fabricate fibres with diameter lower than 0.5 ┬Ám. As the collection efficiency is a decreasing function of the collector size, nanofiber filters could generally achieve a high collection efficiency. Overall, the solution consisting of adding a thin layer of nanofibers allows increasing the collection efficiency but not countering the pressure drop increase during particle loading and consequently the energy consumption. A possible solution to reduce the pressure drop increase is a better distribution of particles collected within the fibrous filter.

In this study, our approach consists in a series association of microfiber filters with various properties...

Session: G13 - Filter Element Design
Day: 24 October 2019
Time: 09:00 - 10:15 h

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