CPC F01N 3/208 (2013.01) [B01D 53/9431 (2013.01); B01D 53/944 (2013.01); B01D 53/9454 (2013.01); B01D 53/9477 (2013.01); B01D 53/9495 (2013.01); F01N 3/106 (2013.01); F01N 3/2013 (2013.01); F01N 3/2892 (2013.01); F01N 3/32 (2013.01); F01N 3/36 (2013.01); F01N 13/008 (2013.01); B01D 2258/01 (2013.01); F01N 2610/02 (2013.01); F01N 2610/03 (2013.01); F01N 2610/146 (2013.01); F01N 2900/1402 (2013.01); F01N 2900/1602 (2013.01)] | 8 Claims |
1. An exhaust system for an internal combustion engine, comprising:
a combustor air pump selectively supplying air to a combustor located along a first passage;
a three-way valve positioned downstream of the combustor along the first passage;
an electric heater positioned along a second passage downstream of the three-way valve;
an oxidation catalyst or a three-way catalyst positioned along the second passage downstream of the electric heater;
a urea injector positioned along the second passage downstream of the oxidation catalyst or the three-way catalyst;
a selective reduction catalyst (SCR) positioned along the second passage downstream of the oxidation catalyst or the three-way catalyst;
a third passage arranged in parallel with the second passage the third passage coupled to the second passage and entering a fourth passage, the fourth passage extending to an engine exhaust passage and positioned upstream of a group of after treatment devices in the engine exhaust passage.
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