A numerical model of steady-state permeate flux during cross-flow ultrafiltration

被引:29
作者
Lee, YH [1 ]
Clark, MM [1 ]
机构
[1] UNIV ILLINOIS,DEPT CIVIL ENGN,ENVIRONM ENGN & SCI PROGRAM,URBANA,IL 61801
关键词
cross-now ultrafiltration; flux decline; concentration polarization; molecular diffusion; shear-induced hydrodynamic diffusion;
D O I
10.1016/S0011-9164(97)00070-2
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
The mass transport mechanisms during cross-flow ultrafiltration (UF) are mathematically expressed using the two-dimensional convective diffusion equation where the axial diffusion term is neglected for an axial Peclet number much greater than the transverse Peclet number. A numerical scheme is presented to solve the steady-state two-dimensional convective diffusion equation for the case of known uniform permeate flux. However, in the actual cross-flow UF process, the permeate flux along the axial direction is unknown and usually decreases with axial distance. Therefore, an iterative algorithm is developed to predict the steady-state permeate flux based on the assumption that the concentration at membrane surface cannot exceed a certain limiting value. Using the numerical model with an effective diffusion coefficient, which is considered to be the sum of molecular diffusion and shear-induced hydrodynamic diffusion coefficients, the effects of particle size, feed concentration, and axial velocity on the steady-state permeate flux were investigated.
引用
收藏
页码:241 / 251
页数:11
相关论文
共 18 条
[1]   LATERAL MIGRATION OF SPHERICAL-PARTICLES IN POROUS FLOW CHANNELS - APPLICATION TO MEMBRANE FILTRATION [J].
ALTENA, FW ;
BELFORT, G .
CHEMICAL ENGINEERING SCIENCE, 1984, 39 (02) :343-355
[2]   LAMINAR FLOW IN CHANNELS WITH POROUS WALLS [J].
BERMAN, AS .
JOURNAL OF APPLIED PHYSICS, 1953, 24 (09) :1232-1235
[3]  
Blatt W, 1970, MEMBRANE SCI TECHNOL, P47, DOI 10.1007/978-1-4684-1851-4_4
[4]  
CHELLAM S, 1991, AWWA SEM P, P675
[5]  
CHERYAN M, 1984, ENG FOOD, V1
[6]  
CHERYAN M, 1986, ULTRAFILTRATION HDB
[7]   LATERAL MIGRATION OF SOLID PARTICLES IN POISEUILLE FLOW .I. THEORY [J].
COX, RG ;
BRENNER, H .
CHEMICAL ENGINEERING SCIENCE, 1968, 23 (02) :147-&
[8]   SHEAR-INDUCED TRANSPORT OF A PARTICLE LAYER ALONG A POROUS WALL [J].
DAVIS, RH ;
LEIGHTON, DT .
CHEMICAL ENGINEERING SCIENCE, 1987, 42 (02) :275-281
[9]   ULTRAFILTRATION OF SUSPENSIONS [J].
FANE, AG .
JOURNAL OF MEMBRANE SCIENCE, 1984, 20 (03) :249-259
[10]   FOULING OF ULTRAFILTRATION MEMBRANES - LATERAL MIGRATION AND THE PARTICLE TRAJECTORY MODEL [J].
GREEN, G ;
BELFORT, G .
DESALINATION, 1980, 35 (1-3) :129-147