Limiting Current Density in the Electrodialytic Equipment with Spacers

Abstract

The limitign current density in the electrodialytic equipment with spacers has been studied quite extensively. However, the estimating equation which represents exactly the effect of the spacer on the limiting current density has not been presented yet.
In order to make clear the relation between the limiting current density and the characteristics of spacers, this study was conducted to measure limiting current densities in the electrodialytic equipment by varying the kind of spacer, the clectrolyte, the operating temperature, the concentration of the inlet solution, and the flow velocity.
From the above results, the values of the constants m and β in the estimating equation on the limiting current density which were derived by assuming the eddy diffusivity with spacer were 0.5 and 0.007, respectively, in all cases. Therefore, it became evident that the limiting current density i the electrodialytic equipment with spacer could be estimated from the above equation. Further, the spacer of the honey-comb textile was found to be the best among all the spacers tested for the equipment.