Minimization of resistance in pleated-media air filter designs: Empirical and CFD approaches

An empirical correlation of two parameters was developed to optimize the use of media for minipleated air filters and minimize pressure drop of the filter panel. An experiment measured performance of a prototype minipleated filter panel made of commercial filter medium and obtained experimental data to validate the correlation. Issues related to the fluid flow field of the whole system were investigated through numerical analysis using a commercial computational fluid dynamics (CFD) code to analyze in detail the vector flow field and different turbulence models. The Reynolds stress model (RSM) turbulence model best described the experimental data. This analysis, performed in a three-dimensional computational domain with a high number of cells, showed the anisotropic nature of the turbulent shear stress. The result was confirmed also in a simplified two-dimensional computational domain. Simulation of fluid-dynamic behavior of media pleats by CFD allowed prediction of pressure drop as a function of the number of pleats per unit length using different kinds of media. The results can be used as input data for the empirical correlation and allow optimization of full-scale commercial air filters.