Occurrence of salt breakthrough and air-vapor pocket in a direct-contact membrane distillation
Occurrence of salt breakthrough and air-vapor pocket in a direct-contact membrane distillation
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直接接触膜蒸馏中盐突破和气穴的发生
DOI：
10.1016/j.desal.2016.09.033
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发表时间：
2017-01
期刊：
影响因子：
--
通讯作者：
Ju Ge
中科院分区：
文献类型：
--
作者：
Yuelian Peng;Ju Ge
采用一种低装填密度、一侧有渗透孔的聚偏氟乙烯（PVDF）中空纤维膜组件进行直接接触式膜蒸馏（DCMD）。还使用具有不同填充密度的高疏水性聚四氟乙烯（PTFE）膜和低疏水性PVDF膜进行了比较测试。在不同的操作条件下，如进料和渗透液流速以及温度，DCMD的性能进行了全面的研究。很少发现在空闲模式下会发生盐穿透，而在工作模式下会发生空气-蒸汽袋。部分润湿是第一次发现倾向于发生在PVDF膜在空闲模式，这导致盐的突破。较高的进料温度和流速加速了部分润湿。相反，PTFE膜防止部分润湿并阻止盐渗透。在壳侧形成的空气-蒸汽口袋归因于高蒸汽通量和不完全冷凝。填充密度的增加和渗透孔的倒置可以帮助热蒸汽和冷渗透物的混合物消除空气-蒸汽袋，这是第一次观察到和说明。
A polyvinylidene fluoride (PVDF) hollow fiber module with a low packing density and the permeate orifices on one side was used in a direct-contact membrane distillation process (DCMD). Comparative tests were also performed using a highly hydrophobic polytetrafluoroethylene (PTFE) membrane and a low hydrophobic PVDF membrane with different packing densities. Under varying operating conditions such as the feed and permeate flow rates as well as temperature, the performances of the DCMD were comprehensively investigated. It was rarely found that salt breakthrough in an idle mode and air-vapor pocket in an operative mode could occur. Partial wetting was for the first time found tending to happen in the PVDF membrane in idle mode, which led to salt breakthrough. High feed temperature and flow rate accelerated partial wetting. On the contrary, the PTFE membrane prevented partial wetting and blocked salt permeation. The air-vapor pocket formation at the shell side was attributed to a high vapor flux and incomplete condensation. An increase in packing density and the inversion of permeate orifices could help the mixture of hot vapor and cold permeate eliminate the air-vapor pocket, which was for the first time observed and illustrated.
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影响因子：
9.9
作者：
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通讯作者：
Chii-Dong Ho;Cheng-Hao Huang;F. Tsai;Wei-Ting Chen
影响因子：
4.7
作者：
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通讯作者：
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影响因子：
9.5
作者：
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通讯作者：
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影响因子：
9.9
作者：
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通讯作者：
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影响因子：
9.5
作者：
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通讯作者：
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