An analytical model for mass transfer in an electrodialysis cell with spacer of finite mesh

Abstract The proposed “mesh step” model represents the mass transfer process as a laminar concentration boundary layer whose development is periodically interrupted. The boundary layer develops along a given characteristic length at the end of which it undergoes partial mixing, i.e. , it regresses to an earlier, less developed stage, from which the development starts again, etc. Thus the mixing effect of the spacer is represented by two parameters: The mesh size and mixing efficiency. This is compared with a “constant boundary layer” model which assumes a laminar diffusion layer of constant thickness with perfectly mixed bulk flow.