Mass transfer mathematical model for one-side plate steady-state ultrafiltration

A mass transfer mathematical model was developed based on one-side plate steady-state uItrafiltration (UF)，and the numerical solution was obtained by Crank—Nicolson finite difference method． The effects of the feed concentration，channel length，axial velocity，and diffusion coefficient on the concentration at membrane surface andthe concentration protiles were investigated． Furthermore·the operation parameters and the parameters of mem—brane module were all transtorrned into dimensionless ones，and the parameter rejection was included in the mass transfer model，therefore，it can be used to calculate the steady-state ultrafiltration with different rejections． The model was used for the calculation of the ultrafiltration of metal—cutting oil emulsion． The resu1ts show that the con—centratlon polarization can be reduced by increasing the axial velocity to some extent，

but the reduction of concentra—tlon polarization is very small when the resistance of ultrafiltration is very great。