UPGRADED EMISSIONS REDUCTION SYSTEM

摘要

A system is provided that reduces nitrogen oxides in the exhaust gases of an engine by converting nitric oxide (NO) in the exhaust gases to nitrogen dioxide (NO2) prior to injecting ammonia (NH3) into the exhaust gases, and then passing the exhaust gases through a vehicle catalytic converter. Much of the nitric oxide (NO) is converted to nitrogen dioxide (NO2) by passing the exhaust gases first through a catalyzed particulate filter (CPF) (20) such as one containing a nitric oxide catalyst (54). In cases where the exhaust gases must pass from the exhaust gas manifold (12) through an exhaust conduit portion of a length of at least one-eighth meter before reaching the catalyzed particulate filter, that exhaust conduit portion is heavily insulated (50) to result in a high exhaust gas temperature at the downstream end of that conduit portion by at least 30 °C over the temperature without insulation.