Development of a Full-Flow Burner Regeneration Type Diesel Particulate Filter Using SiC Honeycomb

A diesel particulate filter (DPF) for city buses was developed that combines a SiC filter and a full-flow type burner for regeneration. Filter crack problems were averted by suppressing the peak temperature inside the filter to under 900°C. This was done by setting the maximum tolerable amount of collected particulate mass before regeneration at 50 g and controlling the burner so as to increase the regeneration gas temperature slowly up to a set value. This DPF was retrofitted to a Tokyo metropolitan bus to conduct a field test. The field test has been under way for half a year without any trouble or deterioration of system performance.

THE DIESEL PARTICULATE FILTER (DPF) receives much recognition as an effective tool for reducing diesel particulates. However, its practical applications are still quite limited, because to date its durability remains immature. To solve this durability problem, Ibiden and Nissan Diesel (hereinafter called “ND”) have been developing a wall-flow monolith type filter made of SiC^(1.2)*, which has desirable characteristics, especially lower pressure loss and very high temperature resistance. Full-flow type burner is employed that uses diesel oil for regeneration of the SiC filter. To study the practicability of the full-flow burner regeneration type DPF system a city bus equipped with this DPF system has been in practical use for the past year in Tokyo metropolitan area.