往复旋转式中空纤维超滤膜处理大豆乳清

Ultrafiltration of soybean whey using reciprocating rotation hollow-fiber membrane module

采用往复旋转式中空纤维超滤膜装置处理大豆乳清液,实验结果表明,该装置利用膜的旋转速度与料液的流动速度之间的矢量叠加,形成较高的速度梯度,从而很好地延缓膜通量的衰减。增大旋转速度或缩短往复周期均会在膜表面形成更大的流体速度梯度,进而产生更好的剪切强化效果,延缓膜通量的衰减。当旋转速度较高时,改变往复周期对膜过滤通量的影响更明显。回归分析表明,膜总透过液量与速度梯度之间存在一个幂函数关系。能耗分析的结果表明,单位通量能耗率随膜表面流体速度梯度的增大而增大,二者之间的关系接近于一个多项式。

A novel dynamic filtration device with reciprocating rotation hollow fiber membrane was used in the ultrafiltration of soybean whey. Effects of filtration modes and reciprocating rotating parameters on the permeate fluxes of membrane were investigated. A 2D particle image velocimetry （PIV） was used to capture the fluid hydrodynamics, and the energy consumption was measured for analyzing the energy efficiency. Results show that the decline of permeate flux is greatly reduced under reciprocating rotation conditions. Higher rotation speed and lower reciprocating rotation cycle increase the velocity gradient at membrane surface, specific energy consumption and membrane permeate flux. With a relatively higher angular speed of membrane fibers, the effect of reciprocating rotating cycles on membrane permeability is more significant. The membrane permeate yields can be represented by a power function of fluid velocity gradient. A polynomial function is used to describe the correlation between specific energy consumption and fluid velocity gradient. The present specific energy consumption values are larger than that of some previous researches.