A Diesel Particulate Filter or DPF collects the soot and ash particles that are present in the exhaust gas of diesel engines. The diesel particulate filter assembly typically consists of active precious metals deposited on a substrate filter. The exhaust gas is forced to flow through the walls of the porous substrate and exit through the adjoining channels. The particulates that are larger than the pore size of the walls are trapped for regeneration. During regeneration the temperature in the diesel particulate filter increases to greater than 550°C (1,022°F). The precious metal washcoat promotes the regeneration of the trapped particulates through the heat-generating reaction and catalyzes the untreated exhaust gas.
