通过调整挤出头尺寸，制备出不同壁厚的PTFE中空纤维膜。采用浸没式真空膜蒸馏（SVMD），研究了膜丝壁厚、操作条件、NaCl浓度等对产水通量和脱盐率的影响。结果表明，降低膜壁厚度可增加产水通量；提高料液温度和冷侧真空度可明显提高产水通量；曝气亦可提高产水通量，当曝气量超过6m3/h*m2时，产水通量反而下降。连续运行800h的实验表明，水通量随工作时间的延长而减小，200h后趋于稳定，脱盐率可保持在99.6%以上。

The Polytetrafluoroethylene (PTFE) hollow fiber membranes with two wall thicknesses were prepared through changing the parameters of extrusion head in this paper. The effect of wall thickness, operational conditions and NaCl concentration of water solution on the permeate flux and salt rejection were investigated by means of submerged vacuum membrane distillation (SVMD). The experimental results shows that the permeate flux increases with the decrease of wall thickness of PTFE hollow fiber membrane. The permeate flux significantly increases with the increase of fee temperature and vacuum pressure. The permeate flux can be enhanced after air-blowing the outer surface of PTFE hollow fiber membrane, and then drop till air blowing intensity is greater than 6m3/h*m2. The 800 hours test shows that the permeate flux decreases with the extension of working time.  After 200 hours, a constant stable water flux is attained with a salt rejection over 99.6%.

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