| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas after-treatment device for a diesel engine capable of constantly maintaining an exhaust gas temperature to about 400°C with which denitration efficiency of a denitration catalyst device can be highly maintained while maintaining a temperature in which black smoke can be burned in a DPF, in an exhaust emission control device in which the DPF and the denitration catalyst device loaded with a reducing catalyst containing urea or ammonia are disposed in series. <P>SOLUTION: In this exhaust gas after-treatment device for a diesel engine, a heat exchanger 131 is provided in an exhaust gas passage 112b between the DPF 122 and the denitration catalyst device 130. The heat exchanger 131 is configured to maintain the temperature of exhaust gas to an optimum operating temperature of urea or ammonia by exchanging heat between cooling water obtained by taking out a portion of engine cooling water and supplied via an engine cooling water delivering channel 138 as coolant with exhaust gas. <P>COPYRIGHT: (C)2010,JPO&INPIT |
