含引流通道的气-液聚结过滤材料的性能试验

Experimental study on the performance of fibrous media with the drainage channels in gas-liquid coalescence filtration

针对空气中油雾的净化问题,对聚结纤维滤料的织物构造提出了一种优化设计。将纤维细度为2μm和6.5μm的不锈钢（SS）纤维滤料及相对应纤维细度的玻璃（G）纤维滤料分别构成内含4个垂直引流通道的多层复合滤料,用气-液聚结过滤性能试验台进行对比测试,计算分析引流通道的构建对滤料捕集效率、阻力特性及品质因数产生的影响。结果表明,在滤层内加插金属网隔片建立若干垂直引流通道对滤料阻力特性有着显著影响,其过滤性能有所改善。在相同条件下,含引流通道的滤料到达阻力稳态阶段需时更长,而且上升过程中瞬时阻力最多可降低30%~50%,品质因数可提高50%~70%。

The paper is aimed at proposing a novel composite medium with large-pore wire mesh spacers in hoping to optimize the performance of the fibrous media in the gas-liquid coalescence filtration for oil mist removal,by which the thin layers of multi-layer media can be separated and created several vertical drainage channels.For the research purpose,we have done experiments and investigated the effects of such drainage channels on the filter media performances,including the capture efficiency（E）,pressure drop（Δp） and the quality factors（QF）.The gas-liquid coalescence experiments of ours have been carried out both on the stainless steel（SS） fiber and the glass（G） fiber of 2 μm,6 μm and 6.5 μm in diameter and 1 cm thick with and without largepore wire mesh spacers for comparison under low Reynolds number flow conditions（Re 1）.As is well known,the performance of coalescing filter media depends on the material properties and operation conditions.In the coalescing filter media series,the multi-layer form with different characteristic features of each layer can help to optimize the properties of media in some way.What is more,it also makes it easy to create drainage channels by isolating the thin layers with spacers,of which the 4 vertical drainage channels can be created in each tested sample.The results of our experiments show that it is of great potential to isolate thin fiber layers by the spacers,which can be expected to display great positive effects on the media performance in gas-liquid coalescence filtration,especially,on the pressure drop of the fibrous media.Besides,the vertical drainage channels can also help to delay the loading of liquid in the subsequent media layers so as to delay the increase of the pressure drop.Under the same experimental conditions in our work,it has taken us a much longer time to have the steady-state pressure drop for isolated media with spacers during the transient period.As a result,we have successfully made the pressure drop significantly lower than the media without spacers（decreased by 30%-50%）.At the same time,the quality factors have been made improved by around 50%-70%.