EXHAUST PURIFICATION APPARATUS

摘要

The object of the invention is to improve mountability on a vehicle by realizing a compact arrangement of a particulate filter 5 and selective reduction catalyst 6 while ensuring satisfactory reaction time for generation of ammonia from urea water. In an exhaust emission control device having particulate filter 5 incorporated in an exhaust pipe 4, selective reduction catalyst 6 capable of selectively reacting NO x with ammonia under the presence of oxygen being arranged downstream of the particulate filter, urea water as reducing agent being adapted to be added between the selective reduction catalyst 6 and the particulate filter 5, the particulate filter 5 is arranged in parallel with the selective reduction catalyst 6. An S-shaped communication passage 9 is arranged for introduction of the exhaust gas 3 from a rear end of the particulate filter 5 to a front end of the adjacent selective reduction catalyst 6 in a forward folded manner. A urea water addition injector 11 is arranged midway of the communication passage 9.