Chemical and Biomolecular Engineering Faculty Research


Coalescence Filter Media with Drainage Channels, Drying Technology

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Fibrous filters are used to remove liquid aerosols from gas streams. Filter media capture fine liquid droplets; the captured liquid droplets coalesce to form big drops and saturate the filter media. This captured liquid typically drains from the filter by gravity. The saturation, or liquid holdup in the filter, constricts the gas flow, reduces capture efficiency, increases pressure drop, and increases the operating costs of the filter. Liquid holdup in the filter also decreases the on-stream life of the filter and requires replacing the filter, which requires shutting down the process and/or equipment being used, which adversely affects the economy of the process. Filter performance improves when the liquid saturation is reduced without reduction in capture efficiency. In this article, glass microfiber filter media are modified with nonwoven polypropylene fabric drainage structures to reduce saturation and drag resistance. The experimental results show that the geometry with embedded nonwoven drainage channels at 45° angles had the best overall performance. Nonwoven drainage channels were investigated with smaller pore diameters than the woven mesh drainage channels previously reported. The results show that the filter performance increased as the pore size of the drainage channel increased up to about 200 µm. Above about 200 µm the performance was independent of the pore size.

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Drying Technology: An International Journal





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