Operating resistance prediction of non-flat HEPA filters

Abstract

The operating resistance of a high-efficiency particulate air (HEPA) filter is affected by the environment and cannot be obtained through the dust holding capacity (DHC) test in the laboratory. For non-flat HEPA filters, studies on the effect of non-uniform deposition of particles on operating resistance were insufficient. We proposed an equivalent permeability coefficient (EPC) method to calculate the operating resistance of the filter and took particle size distribution into account. After comparing with the DHC test data using Arizona test dust (A2 fine dust), it was proved that this method can achieve a relative error of <4%. We found >60% of the particles were deposited in the bottom 2/5 of the V-shaped structures. And the uneven deposition of particles could reduce the operating resistance. Then, we realized the optimal design of structural parameters of V-shape and cylinder filters. • Proposed a novel operating resistance prediction model of HEPA filters. • The uneven particle deposition is beneficial to reduce the operating resistance. • Optimized the structural parameters of the HEPA filters.