膜通道内不同扰流元件强化传质效果

Mass transfer enhancement by various flow disturbers in a membrane channel

为了研究不同扰流元件对膜分离中浓差极化现象的削弱作用,定量研究和分析了膜通道内五种扰流元件的对流强化传质效果,结果表明:三棱柱、四棱柱和圆柱虽然可以有效降低浓差极化因子即有效强化传质,但其所带来的压力损失较大;而具有三维结构的三角翼和矩形翼可以在一定程度上减少浓差极化因子,同时所引起的压力损失比上述二维柱体小得多。通过综合比较五种扰流元件的性能可知:在等压力损失下三棱柱的传质强化效果最差,矩形翼的传质强化效果最好。

Numerical studies were conducted to investigate the concentration polarization weakening effects of five flow disturbers in a membrane channel.The results show that although tri-prisms,quad-prisms,and cylinders can effectively reduce the concentration polarization factor,they cause substantial pressure drops.The delta winglet pair and a rectangular pair as 3D disturbers can moderately reduce the concentration polarization factor with much smaller pressure drops as compared to the 2D disturbers.The overall performance comparison of the five disturbers suggests that for equal pressure drops,the tri-prism design gives the worst mass transfer enhancement while the rectangular pair gives the best mass transfer enhancement.