For increasing the shear stress on a membrane surface to reduce the fouling caused by solid deposition to improve the membrane filtration operation, various hollow fiber arrangements in a filter channel were investigated using computational fluid dynamics. In the simulation process, the velocity and pressure distributions and the effect of shear stress distributions on the membrane surface were analyzed under various hollow fiber arrangements and operating parameters, including fiber diameter (D), transverse pitch (ST), and longitudinal pitch (SL). These parameters lead to a dimensionless Reynolds number Re and the related friction coefficient CfD, which can be used to identify the relationship between different operating conditions.
The study results indicated that CfD of the staggered arrangement was approximately 1.5 times greater than that of the aligned arrangement under the same operating conditions. The fouling tendency in the staggered arrangement was less and more favorable than that in the aligned arrangement, and with a higher SL/D ratio and lower ST/D ratio. With the results from this study, a design direction for optimal geometry to prevent membrane fouling and reduce power consumption was proposed, and can be used as the basis for hollow fiber membrane module design in the future.
Chemical Engineering and Processing - Process Intensification 125, p.87-96