13.6. CROSS-FLOW MODEL FOR GAS SEPARATION BY MEMBRANES
13.6A. Derivation of Basic Equations
A detailed flow diagram for the cross-flow model derived by Weller and Steiner (W3, W4) is shown in Fig. 13.6-1. In this case the longitudinal velocity of the high-pressure or reject stream is large enough that this gas stream is in plug flow and flows parallel to the membrane. On the low-pressure side the permeate stream is almost pulled into vacuum, so that the flow is essentially perpendicular to the membrane.
Figure 13.6-1. Process flow diagram for cross-flow model.
This model assumes no mixing in the permeate side as well as no mixing on the high