Pressure drop and liquid transport through coalescence filter media used for oil mist filtration

Influence of the test emulsion on filtration efficiency and pressure drop of mist separators for cooling lubricants

“…[6][7][8][9]. A first approach to ZASTITA MATERIJALA 58 (2017) broj 4 426 compare the behavior of such mist separator filter elements by a standardized procedure gives the Austrian standard ÖNÖRM Z1263:2013 [10].…”

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

“…A very common way of eliminating oil mist is by fibrous filters (Fairs, 1958;Mohrmann, 1970). During the operation of such filters, aerosol accumulates continuously on the fibers where it coalesces into larger drops which begin to redistribute in the fibrous matrix under the influence of friction forces induced by the gas flow (Walsh et al 1996;Contal et al, 2004;Kampa et al, 2014), and for relatively open-pore media also due to gravity. The accumulation of liquid is associated with a very significant increase in filter pressure drop Δp 1 -usually a multiple of the dry pressure drop (Fairs, 1958;Charvet et al, 2008) -which manufacturers try to minimize by appropriate measures.…”

“…Furthermore, oil mist filters can be composed of both wetting ("oleophilic") and non-wetting ("oleophobic") media with rather different behaviors, or even mixtures of both types of fibers (Kulkarni et al, 2012). Kampa et al (2014) developed special techniques to investigate the distribution and transport of oil in multi-layer stacks of glass fiber media. These techniques permitted to observe in greater detail, how characteristic oil patterns develop in wettable and non-wettable media, and to associate these patterns with specific oil transport mechanisms in the filter.…”

“…The model as first formulated qualitatively by Kampa et al (2014) groups the features of oil distribution observed in both wettable and non-wettable filter media by two principal transport mechanisms, which operate in separate regions of the filter, operate independently of each other, and each make a distinct contribution to the wet pressure drop. (The wet pressure drop is defined as the pressure differential above and beyond the Δp needed to move air through the dry filter.)…”

“…These mechanisms operate in separate regions of the filter and make separate (and separately measurable) contributions to the overall wet pressure drop. This new concept, which was first formulated qualitatively in a phenomenological model by Kampa et al (2014), leads to semi-quantitative predictions regarding the dependence of pressure drop Δp and saturation S on filter operating conditions, filter properties and liquid properties. These predictions are first formulated and then validated for a range of wettable and non-wettable filter media in combination with 4 mineral oils of different viscosity.…”