EXHAUST EMISSION CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To regenerate a filter of a particulate removing means even if temperature of exhaust gas drops due to light load operation of an engine.

SOLUTION: A series passage part 31 and a short passage part 34 are disposed at a downstream side of an exhaust pipe 10 through a channel change over valve 35. A first catalyst device 22 is made short and connected to the exhaust pipe 10 at the short passage part 34. A second oxidation catalyst device 28 is connected to a position at an upstream side of the first oxidation catalyst device 22 in series through a bent pipe 33 at the series passage 31 side. The channel change over valve 35 is changed over to the series passage part 31 side from the short passage part 34 when temperature of exhaust gas is dropped due to light load operation of the engine 9. Consequently, exhaust gas from the engine 9 is made flow to the second oxygen catalyst device 28 and the first oxidation catalyst device 22, and is introduced to a filter device 25 under a condition where temperature of the exhaust gas is raised.

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