真空膜蒸馏海水淡化过程的强化研究

Enhancement of vacuum membrane distillation in seawater desalinization

采用气液两相流技术对管状炭膜真空膜蒸馏模拟海水淡化过程进行强化研究。纯水物系和NaCl水溶液的气液两相流强化实验中，相比未通气体时通量分别增加了29％～35％和16％～66％。气体流量、渗透侧真空度和膜组件放置方式对两相流膜蒸馏过程通量的影响结果表明：气液体积流量之比在（1～2）：1时两相流强化效果最佳；通量随着渗透侧真空度的增大而增大，且气液两相流操作在较小真空度时通量增加的幅度大于较大真空度时；膜组件的放置方式对通量影响较大，相对于水平放置时，膜管竖直放置时的通量较大，最大可达水平放置时的131％左右。

Gas-liquid two-phase flow enhancing vacuum membrane distillation （VMD） has been experimentally studied using a tubular carbon membrane. In the gas-liquid two-phase flow enhancing experiment of pure water and NaCl aqueous,the permeate flux increases by 29% -35%, and 16% -66% respectively compared with no gas sparging. Influences of gas flow, permeate-side vacuum degree and membrane orientation on flux are investigated. The results show that when the gas flow to liquid flow is （ 1 - 2） ： 1, the enhanced result is optimum. The flux increases with the increase of permeate-side vacuum degree, in addition the flux amplitude is greater when the permeate-side vacuum degree is lower compared with the higher one. Also the influence of membrane orientation is very important, and the membrane mounted vertically leads to flux enhancement as high as about 131% as horizontally.