| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device for materializing a simultaneous reduction of particulates and NOx while securing a consistently high NOx reducing rate independently of operating conditions. <P>SOLUTION: The exhaust emission control device comprises a selective reduction type catalyst 5 provided as a NOx reducing catalyst on the midway of an exhaust pipe 4 and characterized so that NOx selectively reacts with ammonia under the coexistence of oxygen, and a particulate filter 13 provided on the upstream side thereof. On the front stage of the particulate filter 13, a burner 14 is provided for igniting and burning a proper amount of injected fuel. Between the particulate filter 13 and the selective reduction type catalyst 5, an oxide catalyst 15 is interposed for giving oxidation treatment to unburnt HC in exhaust gas 3 and promoting oxidation reaction of NO in the exhaust gas 3 into NO<SB>2</SB>. <P>COPYRIGHT: (C)2009,JPO&INPIT |
