Diesel exhaust pre-filter has electrically heated surface bringing exhaust gases to particle self-ignition temperature

摘要

In a process to regenerate an automotive diesel engine exhaust filter, a soot particle filter is located before a ceramic honeycomb exhaust gas filter. The soot particle filter has especially a heating element which is activated during the regeneration phase and heats the particles to their ignition point causing exothermic release of heat from the particles to the exhaust gases. The heated exhaust gases then reach or exceed the soot particle ignition point. An Independent claim is also included for an exhaust assembly with a soot particle collector which separates less than 50% of the soot particles. The soot particle collector and filter medium have a catalytic coating or themselves have catalytic properties. A number of soot particle filters are arranged in series. Each filter has a series of heating elements which are activated sequentially and maintain the downstream exhaust gases at the ignition temperature. The soot collected in the pre-filter is of higher density than that collected in the main ceramic filter.