Time-lapse Visualization of Ash Deposition in Diesel Particulate Filter

Abstract

The ash deposition process on the wall surface of a diesel particulate filter was investigated through time-lapse visualization utilizing a field-emission scanning electron microscope. The components of zinc and phosphorus included in the primary particles of particulate matter (PM), as well as other large ash particles consisting of calcium, zinc, sulfur, and phosphorus in a PM cake layer, were sintered as an ash layer. These ash components were deposited locally around the perimeters of surface pores during a regeneration process. The pressure drop in the filter was reduced by the growth of the ash layer.