A Theoretical Model of Flow in a Pleated Filter Membrane Cartridge*

A 3D model is developed for fluid flow in a cylindrical pleated membrane filter cartridge consisting of a central hollow region surrounded by annular pleated membrane within an external housing. In the region outside of the pleated filter and the hollow region, flow is described using Stokes equation, while in the pleated membrane region Darcy's law is used to model flow through the porous pleated membrane. The governing equations are reduced by exploiting the small aspect ratios of both the membrane and housing. This yields a coupled simplified system of equations for the pressures and velocities in these three regions which is solved numerically. The model is used to investigate the effect of changing various pleated membrane cartridge geometrical parameters on the filter efficiency