PVDF膜用于真空膜蒸馏淡化盐水的实验研究

Experimental Study on Vacuum Membrane Distillation Based on Brine Desalination by PVDF

采用聚偏氟乙烯(PVDF)中空纤维疏水多孔膜,配制Na Cl溶液,搭建真空膜蒸馏盐水淡化实验台,实验中着重考察了料液温度、料液流速、料液浓度、系统真空度等操作参数对真空膜蒸馏过程性能的影响.实验结果表明:随着真空度、料液温度的提高,真空膜蒸馏膜通量明显提高;随着料液浓度的提高,真空膜蒸馏膜通量下降,其截留率基本不变;随着料液流速的提高,真空膜蒸馏膜通量变化较缓慢(略微提高).系统在料液温度为88℃、料液流速为240 cm/min、真空度为0.081 MPa、料液浓度为5%时,真空膜蒸馏膜通量为14.1 kg/(m^2·h),截留率为99.8%,产水的电导率保持在12μs/cm.

Based on polyvinylidene fluoride （ P VDF） hollow fiber hydrophobic porous membrane, vacuum membrane distillation desalination test bench is built to prepare NaCl solutions and to study the effects of operating parameters such as liquid temperature, flow rate, feed concentration and system vacuum degree on the performance of vacuum membrane distillation process. The experimental results show that with the in-crease of vacuum degree, feed liquid temperature, the vacuum distillation membrane flux increases; with the increase of feed concentration and the decrease of membrane flux, the retention rate is essentially the same; with the increase of the feed flow rate, membrane flux changes slowly（slight increase） .When the material liquid temperature is 88 Tl ,the material liquid flow rate is 240 c m/ min,the vacuum degree is 0.081 M P a, the material liquid concentration is 5 % , the membrane flux is 14.1 kg/ （ m 2·h ）,the retention rate is 99.8% ,the conductivity of water is maintained at 12μs /cm .