Experimental Measurements of Particulate Matter Distribution in a Catalyzed Particulate Filter

Abstract

The investigation of the distribution of particulate matter (PM) inside a catalyzed particulate filter (CPF) is studied in this work. The goal was to identify how loading, passive oxidation, active regeneration, and post loading conditions affect the PM distribution. The PM distribution was measured using an Advantest TAS7000 3D Imaging Analysis System, which nondestructively measures the PM distribution. A total of nine experiments were conducted, resulting in three loading scans, four passive oxidation scans, four active regeneration scans, and two post loading scans. The loading experiments were run with two different target PM loadings of 3 and 5 g/L. The passive oxidation experiments were run under two different engine conditions, and four different amounts of PM were oxidized. The active regeneration experiments were run at two target temperatures of 525 and 600 °C, and four levels of PM were oxidized. One post loading experiment was completed after a passive oxidation, and one was completed after an active regeneration. The results show that the PM distribution after loading is similar to the model-predicted PM distribution, which is calculated using the wall flow velocity distribution. The amount of PM in the substrate affects the axial distribution uniformity. The amount of PM passively oxidized or actively regenerated affects the axial distribution uniformity as well. The effect of post loading is dependent on whether the PM was passively oxidized or actively regenerated.