Membrane Technology and Engineering for Water Purification, 2nd Edition

2.4.4 Cross-flow (constant pressure) UF/MF design

Cross-flow systems typically operate at constant pressure and not at constant flux. The design and mode of operation of UF and MF systems are defined by the process needs and application. There are three main process configurations: (a) single-pass, (b) batch filtration, and (c) feed-and-bleed [34,48]. By contrast, all RO and NF systems are of single-pass design. Batch and feed-and-bleed designs involve extensive recycling to remove ≥ 95% of the solution as permeate. In biological applications, heat exchangers are required in the recycle loop for cooling to protect biologicals and proteins from irreversible damage.

Single-pass system

The single-pass process schematic shown in Figure 2.28a is ...