Optimum process designs for ultrafiltration and crossflow microfiltration systems

This presentation gives methods by which ultrafiltration and crossflow microfiltration system designs can be developed and optimized when data are available relating flux rate and membrane rejection to concentration and to other parameters. System layouts considered include batch, single-stage feed-and-bleed, and multi-stage feed-andbleed. Membrane types considered include hollow fiber, spiral-wound, tubular and flat sheet. A math program such as that in EXCEL is convenient for the design calculations. A FORTRAN program to handle additional parameters such as variable recovery per pass and membrane rejections that change with concentration has been developed. A progress report was presented at ICOM 2000 in Toronto and this paper is a continuation of that work.

The knowledge of the process design equations for different ultrafiltration and microfiltration system configurations will enable the design engineer to optimize system design on the basis of yield or membrane area. However, additional economic factors must be considered in order to optimize on the basis of the most costeffective production. This paper gives a sampling of the design equations for three of the most common system designs. A longer, more complete paper is in preparation.