Coalescing filters are used to remove small droplets from air streams. They have numerous industrial applications including natural gas purification

engine crankcase ventilation and compressed air filtration. The evolution of pressure drop

penetration and saturation of oleophilic oil mist filters that distributed in different pore sizes during the process of gas-liquid filtration were examined. The effect of pore size distribution on filtration performance

liquid distribution form and droplet re-entrainment was also evaluated experimentally. The results showed that

when in “channel pressure” stage during the process of gas-liquid filtration

there was significant layering characteristic in the variation curves of pressure drop for filters with pore size distributed increasingly

as well as penetration of droplets above 0.8 μm. There existed a clear difference of steady-state filtration performance between filters with various pore size distribution

which was mainly induced by transfer phenomenon of liquid migration channels inside the filters. By comparing with filters with pore size distributed decreasingly and evenly

it was found that in steady state the filters with pore size distributed increasingly had lower pressure drop

the highest quality factor

less droplet re-entrainment and the highest fractional efficiency for all droplets above 0.8 μm. Therefore

the filters with pore size distributed increasingly were more advantageous for coalescing filter design.