Journal of Industrial Textiles ( IF 3.2 ) Pub Date : 2021-05-09 , DOI: 10.1177/15280837211014239 Ariana Khakpour 1 , Michael Gibbons 1 , Sanjeev Chandra 1
Porous membranes find natural application in various fields and industries. Water condensation on membranes can block pores, reduce vapour transmissibility, and diminish the porous membranes' performance. This research investigates the rate of water vapour transmission through microporous nylon and nanofibrous Gore-Tex membranes. Testing consisted of placing the membrane at the intersection of two chambers with varied initial humidity conditions. One compartment is initially set to a high (water vapour concentration and the other low (, with changes in humidity recorded as a function of time. The impact of pore blockage was explored by pre-wetting the membranes with water or interposing glycerine onto the membrane pores before testing. Pore blockage was measured using image analysis for the nylon membrane. The mass flow rate of water vapour (ṁv) diffusing through a porous membrane is proportional to both its area (A) and the difference in vapour concentration across its two faces (, such that where K is defined as the moisture diffusion coefficient. Correlations are presented for the variation of K as a function of . Liquid contamination on the porous membrane has been shown to reduce the moisture diffusion rate through the membrane due to pore blockage and the subsequent reduced open area available for vapour diffusion. Water evaporation from the membrane's surface was observed to add to the mass of vapour diffusing through the membrane. A model was developed to predict the effect of membrane wetting on vapour diffusion and showed good agreement with experimental data.
中文翻译:
水分冷凝对通过多孔膜的蒸汽传输的影响
多孔膜在各个领域和工业中都有天然的应用。膜上的水冷凝会堵塞孔隙,降低蒸汽透过率,并降低多孔膜的性能。这项研究调查了水蒸气通过微孔尼龙和纳米纤维 Gore-Tex 膜的传输速率。测试包括将膜放置在具有不同初始湿度条件的两个室的交叉处。一个隔间最初设置为高(水蒸气浓度和其他低(,湿度的变化记录为时间的函数。通过在测试前用水预先润湿膜或将甘油插入膜孔上来探索孔堵塞的影响。使用尼龙膜的图像分析测量孔堵塞。通过多孔膜扩散的水蒸气质量流量 ( ṁ v ) 与其面积(A ) 和其两个表面上的蒸气浓度差 (, 这样其中K定义为水分扩散系数。相关性被呈现为K作为函数的变化. 多孔膜上的液体污染已被证明会降低通过膜的水分扩散速率,这是由于孔隙堵塞和随后可用于蒸汽扩散的开口面积减少。观察到从膜表面蒸发的水增加了通过膜扩散的蒸汽质量。开发了一个模型来预测膜润湿对蒸汽扩散的影响,并与实验数据显示出良好的一致性。