Effect of absolute pressure on the fractional separation efficiency of surface filters for particle removal from gases

Surface filters are widely used in industrial gas cleaning to separate particles from dust laden gas flows. During vacuum drying, filtration is performed at reduced absolute pressure, yet systematic data on the effect of absolute pressure on separation performance remain limited. This study investigates the influence of absolute pressure on the separation behavior of two surface filter media operated at P$_{abs}=900, 100, and 25 hPa. A polydisperse test aerosol was applied, and total concentrations in the raw gas and clean gas as well as size-resolved number concentrations were measured continuously.