| 摘要 |
<P>PROBLEM TO BE SOLVED: To more suitably supply reducer to a particulate filter when a front stage catalyst having oxidation function, a storage reduction type NOx catalyst, and the particulate filter carrying the catalyst having oxidation function, are arranged in order from an upstream side. <P>SOLUTION: This system is provided with: a bypass passage formed to pass through the front stage catalyst 4 and the NOx catalyst 5 and making exhaust gas flow with bypassing the catalysts; an open close valve 9 shutting off and opening the bypass passage 8; and a reducer adding valve 7 adding reducer into exhaust gas in a direct upstream of an upstream side opening part of the bypass passage 8 in the exhaust passage 2. When reducer is supplied to the filter 6, reducer is added from the reducer adding valve 9 in the state where the bypass passage 8 is opened by the open close valve 9. <P>COPYRIGHT: (C)2008,JPO&INPIT |
