Filtration Performance of Coalescence Filter with Nanofiber Membrane

Glass fiber filter media are widely used to remove submicron liquid droplets from air and gas streams. However, there is still a challenge to obtain filter media with high efficiency and low resistance. In this study, the electrospinning method was used to deposit a nanofiber membrane on the micron fiber filter media. The filtration performance and liquid distribution in the filters with different electrospinning area ratio were analyzed. The filtration performances of dual-layer filters with different combinations were investigated. The results show that with the increase in electrospinning area ratio, the filtration efficiency of oleophilic filters can be improved, while it seems to have no effect on the filtration efficiency of oleophobic filters. At the initial stage of filtration, there is liquid film forming on the electrospinning area for both the oleophilic and oleophobic filters, resulting in an increase airflow resistance on the non-electrospinning area. As the nanofiber membrane is coated on the up region of the first layer filter media, with the increase in the electrospinning area ratio, the steady pressure drop increases for the dual-layer combinations based on oleophilic filter media, while the filtration efficiency increases gradually for the dual-layer combinations based on both oleophilic and oleophobic filter media. The best filtration performance was found for Filter B-U75-D25.