关键词: 二次夹带, 气溶胶, 过滤, 润湿性, 过滤速度, 天然气

Abstract:

In long-distance transmission of natural gas, safe operation of compressor units is seriously affected by droplets entrained in natural gas. The characteristics of re-entrainment in gas-liquid filtration process of filter cartridges were investigated using liquid aerosol of di-ethyl-hexyl-sebacate (DEHS). The effects of filter material wettability and filtration velocity on re-entrainment were also evaluated experimentally. Re-entrainment could be observed in the process of filtration as filter cartridges only composed of coalescing layers. More droplets were entrained into the downstream due to re-entrainment and some large particles could be detected at the downstream. Cumulative efficiency decreased at the large particle size at steady state. Re-entrainment was affected by filter material wettability. Compared with non-wettable filter material, re-entrainment was more obvious on the surface of wettable filter material. To improve filtration efficiency, non-wettable filter material were more suitable for producing industrial filter cartridges at the same filtration velocity. As filtration speed increased from 0.1 m·s^-1 to 0.3 m·s^-1, higher filtration velocity led to less re-entrainment, and filtration performance of wettable filter cartridges were improved more significantly than that of non-wettable filter cartridges. Re-entrainment could be eliminated by adding drainage layer to filter cartridges.

Key words: re-entrainment, aerosol, filtration, wettability, filtration velocity, natural gas