A diesel particulate filter（DPF）is one important technology that would allow the regulation of particulate matter（PM）emission. Although high filtration efficiency is achieved after thin soot layer is formed on the surface of the porous ceramic filter wall, a few PMs are passing through the DPF on initial usage. Therefore, the examination between soot layer formation and the mechanism of PM filtration is needed. In this study, the initial filtration efficiency of SiC-DPF was measured by using PM counter, with SEM observation of the soot layer formation. In addition, the quantification of soot layer formation was examined by the surface roughness. Results showed that as soot layer was formed, the value of surface roughness was smaller, and the filtration efficiency reached higher. Thus, there is a correlation between the filtration efficiency and the surface roughness, and the degree of soot layer formation can be evaluated quantitatively by the surface roughness.

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[in Japanese]

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