膜内气压和液相流速对无泡膜曝气氧传质性能的影响

Effects of Intra-membrane Air Pressure and Liquid Velocity on Oxygen Transfer Performance in Bubbleless Membrane Aeration Reactor

探究了膜内气压（P）及液相流速对无泡膜曝气氧传质性能的影响。结果表明，当P在2kPa以下时，随着P增加，氧传质系数增加；当P为2～10kPa时，随着P增加，氧传质系数逐渐降低。当液相流速从0．014m／s增加到0．041m／s时，氧传质系数呈上升趋势，但增加幅度不大。同时给出了膜曝气反应器内舍伍德数（Sh）随膜内气压、雷诺数（Re）和施密特数（So）的变化关系式，当P为0～2kPa时，跏与P呈正相关，说明氧传质性能随压强的升高而增强；当P为2～10kPa时，肌与P呈负相关，说明此时氧传质性能随压强的升高而减弱。

The effects of intra-membrane air pressure （P） and liquid velocity on oxygen transfer performance were investigated in a bubbleless membrane aeration reactor. The results showed that oxygen transfer coefficient increased when P was below 2 kPa, but oxygen transfer coefficient decreased when P increased from 2 to 10 kPa. Oxygen transfer coefficient increased slightly when liquid velocity increased from 0.014 m/s to 0.041 m/s. The relationships of Sherwood number （Sh） to intra-membrane air pres- sure, Reynolds number （Re） and Schmidt number （Sc） in the bubbleless membrane aeration reactor were presented. Sh was positively correlated to P when P increased from 0 to 2 kPa, indicating that the oxygen transfer performance was enhanced with the increase of the pressure. Sh was negatively correlated to P when P increased from 2 to 10 kPa, indicating that the oxygen transfer performance was weakened with the increase of the pressure.