Abstract A series of experiments have been carried out to examine the performance of porous spacers proposed for increasing the limiting current density, since it is of fundamental importance to find an optimal operate condition in an electro-dialysis. The fluid mixing in the porous material can play an important role to suppress the concentration polarization and achieve a high limiting current density. The effect of porous spacers filled in both dilute and concentrate channels on the stack voltage and the limiting current density has been investigated by comparing the cases with and without porous spacers. It has been found that the limiting current density with porous spacers is 1.8 to 3.3 times higher than that without a porous spacer as a result of mechanical dispersion caused by fluid mixing in porous materials. Furthermore, the increase ratio of limiting current density with the present spacers to that without spacer is higher than that of conventional mesh spacers. Moreover, it was found that the electrical resistance does not increase even when inserting the present porous spacers by comparing that of conventional mesh spacers, since the present porous spacer can suppress the concentration polarization concerned with electrical resistance. On the other hand, the increase in the pumping power turns to be negligible small by comparing the electrical power for an electro-dialysis since permeability of the present spacers is sufficiently high. In this study, it has been proven that the insertion of porous spacers is quite useful in terms of limiting current density, electrical resistance and pumping power.

中文翻译：

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多孔隔板对电渗析脱盐中极限电流密度的影响

摘要 由于在电渗析中找到最佳操作条件至关重要，因此已经进行了一系列实验来检验为提高极限电流密度而提出的多孔隔板的性能。多孔材料中的流体混合对抑制浓差极化和实现高极限电流密度起着重要作用。通过比较有和没有多孔隔离物的情况，研究了在稀释和浓缩通道中填充的多孔隔离物对堆电压和极限电流密度的影响。已经发现，由于流体在多孔材料中混合引起的机械分散，使用多孔间隔物的极限电流密度比没有多孔间隔物的极限电流密度高 1.8 到 3.3 倍。此外，本发明的间隔物与无间隔物的极限电流密度的增加比高于传统的网状间隔物。此外，通过与常规网状间隔物的比较发现，即使插入本多孔间隔物时电阻也不会增加，因为本多孔间隔物可以抑制与电阻有关的浓度极化。另一方面，与电渗析的电功率相比，泵浦功率的增加变得可以忽略不计，因为本隔板的渗透性足够高。在这项研究中，已经证明插入多孔垫片在限制电流密度、电阻和泵浦功率方面非常有用。