鼓泡条件对浸没式中空纤维膜微滤过程膜污染的影响

The effect of gas bubbling in a microfiltration process with a submerged hollow fibre membrane

在不同的鼓泡条件(气体流量、气孔间距和膜丝松弛度)下测定了浸没式中空纤维膜组件在恒通量微滤过程中的跨膜压差。结果表明,增大气体流量能够控制膜污染,但其有效程度随气体流量的增加逐渐减弱,气体流量为0.15m3/h和0.2 m3/h时!p/!t的值相近;双孔集中分布比分散分布更能控制膜污染,但单孔鼓泡控制效果弱于双孔集中分布;膜丝的适当松弛有利于控制膜污染,且气体流量越大效果越显著,气体流量为0.1m3/h时97%松弛度的污染控制效果最佳。

Microfiltration processes have been investigated experimentally by measuring trans-membrane pressure for a constant membrane flux under different bubbling conditions（gas flow rate,nozzle distance and tightness）.The results showed that membrane fouling can be controlled at higher gas flow rates,although the fouling control effect gradually decreased.The value of △p/△t for a flow rate of 0.2m3/h was close to that for a flow rate of 0.15m3/h.An inlet mode involving double nozzles with a concentrated distribution was better in terms of fouling control than an inlet mode with a dispersed distribution,but an inlet mode of a single nozzle was less effective than an inlet mode with double nozzles and a concentrated distribution.Looser membrane silks were beneficial in terms of controlling membrane fouling,especially under high gas flow rates.A nozzle tightness of 97% and air flow rate of 0.1m3/h were found to be the optimal conditions for the microfiltration process.