Exhaust purification device and exhaust purification method for an internal combustion engine

摘要

An exhaust system for an internal combustion engine (1) includes a catalytic device (16) within an exhaust path (15) of the engine, wherein the catalytic device (16) includes a housing (19) with a catalyst carrier (21). A length of the catalyst carrier (21) along a longitudinal axis, measured along a downstream flow direction of exhaust gas within the exhaust path (15), is substantially the same or a shorter than the upstream distance traveled by a reverse flow of exhaust gas during an exhaust gas pulsation within the housing. With this type of configuration, due to reciprocating movements of the exhaust gas caused by the pulsations, the same exhaust gas passes through the catalyst carrier multiple times. Thus, an increased number of heat exchanges take place within the catalyst carrier, which rapidly increases the catalyst temperature after a cold engine start.