Leakage currents in electrodialytic desalting and brine production

Abstract

The effective electrical leakage, as a fraction, is given by the equation ▪ which includes the effect of external leakage through manifolds with resistance ε. Even wide variations of the compartment pair resistance R were found to have little effect on the total leakage and for a leakage calculation it usually suffices to use an average value for R. In many applications of electrodialysis it is more important to have a high resistance r between compartments and flow channels than a high flow channel resistance δ (the ratio being reflected in γ=(δ+R)/r). The number of compartment pairs (2N) in a membrane pack is limited in any case because of mechanical and flow distribution problems and with respect to the latter low values of δ (large flow channels) are desirable. The results shown invalidate some of the conclusions appearing in the earlier literature.