长度及出水方式对中空纤维膜过滤性能的影响

Effects of length and effluent style on hollow fiber filtration performance

为了更好的对中空纤维膜组件进行优化设计,通过对4组试验的对比,就中空膜纤维的长度和膜组件出水方式对过滤性能的影响进行考察.结果表明:无论是静态过滤还是曝气条件,在试验周期内,单端出水组件的膜比通量要比双端出水组件的变化趋势更为平缓.相同条件下,双端出水组件的平均通量要高于单端出水组件.静态过滤条件下,双端比单端的稳定运行通量有较大提高;在曝气条件下,由于气泡诱发的纤维抖动和水力错流作用,曝气对通量的影响要大于出水方式对通量的影响.在本研究的条件下,固定曝气强度为7.99 m3/(m2.h),100～120 cm为单端出水的膜纤维最佳长度设计值,在此范围内膜比通量与短纤维相比不会有明显的降低.当组件的出水方式改为双端时,膜纤维的最佳设计长度可延长至120～140 cm.

To optimise the design of a hollow fiber membrane module, four groups experiments were conducted to determine the effects of length and effluent style on hollow fiber filtration performance. The results show that the curve profile of specific flux vs. operation time of membrane module suction in one end is plainer than that in both ends under the conditions both stable filtration environment and aeration enhanced. In same environment, steady flux of the module suction in both ends is higher than module suction in one end in a long period. In aeration enhanced environment, because of fiber waving and cross flow sweeping induced by bubbles, the effects of the aeration on flux are higher than the effect of suction styles. In this study, 100-120 cm is the optimal fiber length which can maintain a high flux. Moreover, when the module suction in both ends is used, 120-140 cm is the optimal fiber length.