浸入式中空纤维膜组件在线反洗参数分析

根据浸入式中空纤维膜组件应用特点,对反洗压力和反洗流量在线反洗中的控制进行了讨论,并对膜组件安装位置对在线反洗的影响和在线反洗操作模型进行了分析.认为保证距膜纤维出水口最远处,即"最不利"点的清洗效果是在线反洗参数设计的基本原则.当考虑膜组件安装位置产生的重力水头影响时,组件放置高于系统出水点时应控制的最低反洗压力为b/K'+H;当组件低于系统出水点时应控制的最低反洗压力为b/K'-H.根据单根纤维反洗传质模型引入在线反洗参数ζ,当Q'/p_e<ζ时,不能保证沿整个膜纤维得到有效清洗.在反洗流量和压力一定时,对应的反洗压力和流量均存在效率最高值,最佳反洗压力和反洗流量的选择可根据最高效率范围进行选择.

Study on cleaning in line parameters of submerged hollow fiber module

Based on submerged hollow fiber membrane module operation performance, backflushing pressure (BP) and backflushing flux(BF), the two key parameters of cleaning in line (CIL) operation, were discussed in this paper. The influence of gravity on CIL and CIL operation model were analyzed. It was considered that CIL operation strategy should made the backwashing solution arrive at fiber surface which was the farthest from the effluent end. When the membrane module position is higher than effluent point, it should control the minimum BP higher than b/K' + H, on the contrary, it should control the minimum BP higher than b/K' - H when the membrane module position is lower than effluent point. According to the backwashing filtration model of submerged hollow fiber membrane, a parameter of backwashing ζ was put forward. When Q'/p_e<ζ, backwashing liquid could not covered the whole membrane fiber. The numerical simulation of CIL operation showed that,when the BP and BF are fixed value, the corresponding BP and BF have maximum efficiency range, the optimal BP and BF could be designed base on this region.