Drop entrainment from the surface of oil mist filters: mechanisms, kinetics, and drop spectra

Oil entrainment from coalescence filters has been characterized by different techniques. Drop spectra and entrainment rates were measured by a combination of techniques from <1 μm up to >1 mm over long periods of time. Dominant entrainment mechanism(s) are identified on the basis of comparisons of entrainment rates measured in different regions of the filter surface with rates of air bubble formation, measurements of oil film thickness, as well as visual observations. Experiments are supported by force estimates to entrain oil into the gas flow.