Oil-mists coalescence performance of fibrous filters with superoleophilic and superoleophobic surface

The surface wettability of fibers in coalescing filter has a critical effect on filter's performance. In this study, we employed common glass fiber filters as model and prepared superoleophilic and superoleophobic surface filters via a facile dip-coating method. The superoleophilic treatment shows a considerable reduction in pressure drop. The wet pressure drop at saturation decrease from 12.91 kPa to 8.56 kPa after superoleophilic coating. The filtration efficiency of fine particles (<100 nm) increase owing to coating treatment. The combinations of superoleophilic and superoleophobic filter and drainage strategy were also evaluated. The results show that the combination has no advantage due to emergency turn of wettability. The drainage layer with appropriate rank could enhance the drainage rate at unsaturation stage. However, the drainage strategy is never a good idea to improving coalescence performance because it brings the extra pressure drop. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

The study found that employing superoleophilic treatment in filters can reduce pressure drop and improve filtration efficiency, while the combination of superoleophilic and superoleophobic filters with drainage strategy did not show significant advantages. An appropriate rank of drainage layer could enhance drainage rate at unsaturation stage.