Validation of a new phenomenological “jump-and-channel” model for the wet pressure drop of oil mist filters

Measurement of oil entrainment rates and drop size spectra from coalescence filter media

“…This has to do with the way oil drains intermittently across the downstream face of a filter (Liew and Conder, 1985;Kampa et al, 2014) and requires the ability to monitor a large region of the filter surface. A third difficulty, affecting especially the detection of large drops, arises from the fact that the operating behavior-and therefore presumably also the entrainment behavior-of coalescence filters changes gradually over very long periods of time (Conder and Liew, 1989;Contal et al, 2004;Charvet et al, 2010;Kampa et al, 2015). For example, it typically takes several hours for a filter to reach steady state, during which oil accumulates and thereby increases the interstitial air velocity, which presumably also affects entrainment.…”

High‐Efficiency Low‐Resistance Oil‐Mist Coalescence Filtration Using Fibrous Filters with Thickness‐Direction Asymmetric Wettability

“…In principle, coalescence‐driven aerosol mist filtration is a complex process involving capturing oil mists with filter, coalescing oil liquid within filter matrix, and oil disposing . The overall capture efficiency (η T ) of a fibrous filter can be theoretically described as: (where Z is filter thickness, α is packing density, and d f is mean fiber diameter).…”

“…It was reported that lowering oil wetting ability on fibers could reduce oil re‐entrainment into the downstream . Filters with better wettability lead to smaller increase in flow resistance . Recently, Wei et al from our group has elucidated that a fibrous filter after superoleophobic treatment shows largely improved oil mist filtration efficiency without apparently increasing pressure drop.…”

The effect of a drainage layer on filtration performance of coalescing filters

“…Kampa et al [27,28] have proposed a ''jump-and-channel" model to analyze the wet pressure drop, which illustrates the increase in pressure drop due to liquid deposition in the filter. The wet pressure drop consists of the channel pressure drop and the jump pressure drop.…”

“…Jump pressure drop is determined by the material properties of the filter material, rather than the operating conditions [28]. All coalescing layers were composed of the same glass fibers in this study.…”