IC engine exhaust filter cleaning system - has box calculating when set degree of clogging has been reached and controlling heater to induce soot burning

摘要

The exhaust filter(3) is cleaned by burning off the soot when the pressure drop across the filter indicates that cleaning is necessary. A control box (41) monitors the pressure drop, the engine speed, engine load, engine coolant temperature and temperatures at the inlet and outlet of the filter. - The box calculates when a predetermined degree of clogging has been reached and controls an engine air inlet throttle valve (6), valves (21 and 25) respectively upstream of and bypassing the filter and a heater (29) to induce soot burning. The valves and heater are operated in various combinations depending on the engine speed and load. Thus the heater is not always used.