Numerical study and optimization of pleated gas filters

A numerical model has been developed to optimize the design of pleated filter panels. In this model, the fluid flow is modelled by a steady laminar flow and the filter media resistance is governed by the Darcy-Lapwood-Brinkman equation. A finite element method with a nine-node Lagrangian element is used to solve the governing equations. For the rectangularly pleated filter panel, the numerical results agree well with the analytical model of Yu and Goulding and with his experimental data. The pressure drop increases at small pleat count due to increased media face velocity, and at large pleat count due to increased viscous drag. Therefore, an optimal pleat count for minimum pressure drop exists at a certain pleat height for each filter media type. The optimization of rectangular pleated filter, e.g., mini-pleated filter, panels has been performed for six commercial filter media. The optimal pleat count is shown to increase with decreasing media permeability of the filter media. A generalized correlation curve has been found for each filter media type by using a nondimensional parameter group together with a minimum pressure drop normalization. The results can be used to design a pleated filter panel with minimum pressure drop.