Spiral wound modules performance an analytical solution: Part II

Abstract

An analytical solution for the performance of the spiral wound modules is presented for sea water as feed. This analysis takes into account pressure losses in both permeate and brine channels, the effect of concentration polarization and the concentration gradient along the membrane. A five-parameter model is introduced. The parameters are: k fb (brine friction parameter), k fp (permeate friction parameter), k 1 (water permeability coefficient), k (mass transfer coefficient) and k 2 (solute permeability coefficient). A procedure to determine the first three parameters from pure water tests has been presented in a previous paper [1]. In this work the other two parameters are found by using explicit equations. Simple equations have been suggested for all the parameters, and predictions have been made for the performance of the module at any operating conditions. The analysis has been based on the solution-diffusion model and the thin film theory. The theoretical values for the water flux and the permeate concentration are in good agreement with the experiment.