Patent ID: 7673447
Filing Date: 2010-03-09
Classification: F01N,Y02A,Y02T

Abstract:
1. An exhaust system for an internal combustion engine, comprising: an exhaust line in which an oxidation catalyst is arranged for treating the exhaust gases coming from the internal combustion engine, a pre-oxidation unit arranged in the exhaust line primary flow path of the exhaust gases and upstream from the oxidation catalyst and connected to a secondary fuel supply, distinct from the internal combustion engine, and adapted so that it partially oxidizes the secondary fuel supplied in combination with an oxidizer in a catalyst heating operation and the partially oxidized intermediates are supplied to the oxidation catalyst for complete oxidation, wherein the pre-oxidation unit includes a first catalytic converter to initiate and maintain the partial oxidation, and a second catalytic converter downstream from the first catalytic converter, and wherein the pre-oxidation unit has a first oxidizer feed which introduces the oxidizer into the pre-oxidation unit upstream from the first catalytic converter and has a second oxidizer feed which introduces the oxidizer into the pre-oxidation unit between the first catalytic converter and the second catalytic converter.