Mass transfer coefficient with suction including property variations in applications of cross-flow ultrafiltration

The modified Sherwood number relationship including the effects of property variations and suction by the membrane for laminar flow in a rectangular c hannel is presented in this work. The modified relationship is used to pred ict the permeate flux of ultrafiltration data of bovine serum albumin and d extran, taken from the literature. The exponent n of the correction factor (Sc/Sc-m)(n) was found to be 0.01 for bovine serum albumin for all feed con centrations; for dextran, n was found to vary with feed concentration (0.01 3 for 5% and 0.026 for 10% solutions). The analysis is valid for the imperf ect membranes as well. Results are also presented for the simultaneous pred iction of permeate flux and permeate quality (in terms of the observed rete ntion). Finally, a parametric study of flux and observed retention is carri ed out to infer the influences of various operating and membrane performanc e parameters. (C) 1999 Elsevier Science B.V. All rights reserved.