| 摘要 |
PROBLEM TO BE SOLVED: To stably remove carbon-containing floating particulates contained in exhaust gas. SOLUTION: A treating catalyst is disposed in an exhaust passage of an internal combustion engine, the carbon-containing floating particulates contained in the exhaust gas are collected, and the collected particulates are combusted using a catalyst action. Flame-retardant particulates such as ash, though the number of them is small, are contained in the exhaust gas. When many particulates accumulate on the treating catalyst, the catalyst action is disturbed to make difficult appropriate combustion of the floating particulates. In such a case, an operation condition of an engine is changed to increase flow rate of the exhaust gas and the particulates accumulating on the catalyst are scattered. Thus, even when many flame-retardant particulates accumulate, the catalyst action can be recovered by scattering the particulates, thereby stably removing the carbon-containing floating particulates contained in the exhaust gas. |
