The study of pleat geometry on the air filtration performance

Abstract

Fibrous filter media is typically pleated to increase effective filtration area, but the pleat geometry could influence the filtration performance. The previous work focused on the pleat geometry numerically and mainly limited to the cartridge filters with small pleats while the study on the heating, ventilation and air-conditioning (HVAC) filters is limited. In this study, a full-size pleated fibrous air filter was used to investigate the effect of pleat geometry on the filtration performance experimentally with reference to the air filter test standard, ISO 16890. The pleat geometry was found to have an insignificant effect on the filtration efficiency. The optimum pleat ratios are 13.08–14.57 for minimum initial pressure differential and 9.96–11.75 for optimal specific resistance coefficient of dust cake, $K_c$ . The overall optimum pleat ratio range is 13.08–14.57 to obtain an optimal filtration performance at low initial pressure differential and low $K_c$ while attaining a high dust holding capacity. The findings of current work were obtained by a comprehensive study on the filtration performance including the clean and dust-loaded states of the HVAC filters, at the actual operating velocity and could be directly applied in the actual filter depth selection based on the AHU’s space limitation.