【摘要】 采用减压膜蒸馏技术在较低真空度下浓缩NaCl水溶液 ,研究了真空度、料液温度、料液流速以及料液浓度对膜通量与截留率的影响。结果表明 ,随着膜下游真空度增加 ,膜通量线性增大 ;料液温度显著影响膜通量 ;随着料液浓度增加 ,膜通量严重衰减 ;实验条件下聚丙烯中空纤维膜表现出很好的疏水性 ,NaCl的截留率接近 10 0 %。更多还原

【Abstract】 The experimental study of concentration of sodium chloride from its aqueous solution by vacuum membrane distillation(VMD)was carried out.The polypropylene hollow fiber membrane(PPHM)was used for the process at lower vacuum degree.The influences of vacuum degree,temperature,composition,flow rate of the liquid feed on the process were investigated. Experimental results showed that with the increase of the degree of vacuum of the cold side,the permeation flux increased linearly.When the temperature increased,the flux increased sharply.The flux was enhanced with the increase of the flow rate.But when the concentration of the salt increased,the flux decreased.It was found that the PPHM possessed perfect rejection property,the separation efficiency was closed to 100%.更多还原