膜器结构对纳滤膜过滤性能的影响  

Influence of membrane module′s structure on nanofiltration separation

作　　者：章鹏兴[1] 陈志[1] 曾凡苏[1] 曹蕾[1] 李建明[1] 

机构地区：[1]四川大学化学工程学院,成都610065

出　　处：《膜科学与技术》2012年第3期28-33,共6页Membrane Science and Technology

摘　　要：旨在通过使用自行设计的平板式纳滤膜组件以及商品膜片进行实验,考察3种不同的膜器流道结构对纳滤膜过滤性能,如通量Jv、表观截留率Robs的影响.3种流道膜器系统(螺旋流道、蛇形流道、无绕流流道)的实验结果表明,在实验条件范围内、相同操作条件下,浓差极化程度对通量有很大的影响.由于二次流对浓差极化层的扰动作用,螺旋流道膜器的通量最大,蛇形流道膜器的次之,无绕流流道膜器的最小.当膜面错流为层流时,螺旋流道膜器的通量接近蛇形流道膜器的2倍;湍流时由于二次流扰动相对较弱,前者的通量约为后者的1.6倍.对于表观截留率而言,流道结构和通量对其影响均较大.层流时无绕流流道膜器对Mg2+的表观截留率最大,可达到94.2%,而螺旋流道膜器的表观截留率高于蛇形流道膜器的值;湍流时由于螺旋流道中二次流的影响减弱,蛇形流道膜器的Mg2+的表观截留率高于螺旋流道膜器的表观截留率,最大为97.1%.In order to investigate the effects of the three kinds of membrane module＇s structures on the NF separation, such as permeate flux and observed rejection, three self-designed flat-plate NF membrane modules and a kind of commercial nanofiltration membrane were used to carry out the experiments. It is shown, from the experimental results of three kinds of membrane module systems （the spiral flow type, the serpentine flow type and the normal flow type）, that at the same operating condition, permeate flux is strongly affected by the concentration polarization on the membrane surface, and the flux of the spiral flow module is the largest due to the disturbance of the secondary flows to the concentration polarization, then is that of the serpentine flow module, and follows by that of the normal flow module. When the flow is laminar, the permeate flux of the spiral flow module is about 2 times greater than that of the serpentine flow module. When the flow is turbulent, the permeate flux of the former is about 1.6 times larger than that of the latter. It is also shown that the structures of the membrane module and the permeate flux have great influence on the solute rejection. When the flow is laminar, the Mg^2＋ rejection of the normal flow module is the greatest, say, up to 94. 2%, and that of the spiral flow module is larger than that of the serpentine flow module. When the flow is turbulent, the Mg^2＋ rejection of the latter is greater than that of the former, e.g. up to 97. 1%, for the effect of the secondary flow on the concentration polarization becomes relatively weaker.

关 键 词：纳滤膜 流道结构 过滤性能 

分 类 号：TQ028.8[化学工程]