| 摘要 |
<p>PURPOSE:To prevent a filter from melting and improve the combustion efficiency of particulates by maintaining a perticulate filter at particular temperatures for certain times over two stages by means of an afterburner and, then, gradually reducing said temperatures. CONSTITUTION:When a selector valve 6 which is installed in a branch part 3a, is connecting, i.e., a branch pipe 3A to an exhaust pipe 3, if a control device 10 judged that the output value of a pressure sensor PA is increased indicating a particulate filter to be clogged, the selector valve is switched by an actuator 8, to connect a branch pipe 3B to the exhaust pipe 3. The control device 10 ignites a burner 7 on the branch 3A side, to burn particulates again collected in a filter 5. In this case, the afterburning temperature of the particulates is first, maintained at 600 deg.C+ or -50 deg.C for a certain time and, then, at 750 deg.C+ or -50 deg.C for a few minutes. After that an upper surface temperature is gradually lowered, completing an afterburning.</p> |
