Comparisons of Experimental and Simulated Velocity Fields in Membrane Module Spacers

Spacers are used in spiral wound and plate and frame membrane modules to create flow channels between adjacent membrane layers and mix fluid within the flow channel. Flow through the spacer has a significant beneficial impact on mixing and resulting mass transfer rates but is accompanied by an undesirable increase in pressure drop. Computational Fluid Dynamics (CFD) is a common tool used to evaluate the effect of spacer design on fluid flow. While numerous theoretical studies are reported in the literature, confirmation of simulation results through experimental velocity field measurements is limited. Comparisons of CFD simulations with experimental velocity measurements using Particle Image Velocimetry (PIV) for traditional symmetric diamond and asymmetric spacer designs and a novel static mixing spacer design are presented. The results include comparisons of the two velocity components in planes parallel to the flow channel walls for the diamond and asymmetric spacer as well as the first reported comparisons of all three velocity components for the static mixing spacer. The results indicate good agreement between theory and experiment and help validate the use of CFD for spacer design.