Flow Characteristics of Feed Solution in PRO Flat Sheet Membrane Modules

Abstract

Flow characteristics of PRO flat sheet membrane modules are researched in relation to the length of the center seal of the feed solution. The permeation performances of the module are examined in experiments and analyzed by means of numerical simulation. It is pointed out that the water permeation decreases with the short center seal, but the pressure loss in the feed solution decreases. The short-cut flow occurs in the feed solution because of the large resistance of the fine mesh of the spacer. There exists a very small flow part ahead of the feed solution so the effective permeation area is decreased. This is closely related to the leakage of salt from the draw solution to the feed solution. The concentration of feed solution accumulates with the leakage of salt. The concentration rapidly increases at the small flow part, and the high concentration continues up to the outlet of feed water. But the short-cut flow decreases the pressure loss in the feed solution so that the power of the feed pump can be decreased.