The effect of the transformation of bubble size and flow pattern on the hollow fiber membrane microfiltration

摘要

In the submerged hollow fiber membrane microfiltration, the shear near the membrane surface induced by the gas bubbling can effectively restrain the formation of the fouling layer. Using yeast as model particle in water, the performance of submerged hollow fiber membrane module was tested by measuring the transmembrane pressure under constant flux. It was found that the nozzle size greatly affected the size and shape of created bubbles, and with the increase of the nozzle size and after exceeding one threshold value, the gas flow pattern transformed from bubble flow to the single bullet-shaped slug flow. The observed membrane fouling performance coincided with the observed two-phase flow characteristics and the results of critical flux experiments.