| 摘要 |
<p>PURPOSE:To efficiently perform the reconditioning of a filter by accurately recognizing a progress state of the reconditioning by providing a combustion sensor composed of optical receiving elements in a downstream side of the filter in the flowing direction of exhaust gas, and controlling a microwave heating means and a control valve according to the variation of the output from the combustion sensor. CONSTITUTION:When it has been estimated that it is the time to recondition a filter 11, in an arithmetic part 23 according to the rotational speed, the fuel consumption, the running time and degree of the pressure loss of an engine 9, a control valve 14 is changed over to the side where total exhaust gas flows into a bypass tube 16, and at the same time, a magnetron 17 which serves as a heating means is driven, and microwave is introduced into a cavity 12 from a waveguide 19 for preheating the filter 11. When the temperature of the filter 11 reaches the ignition temperature A, combustion begins partially. When the combustion zone expands until output from a combustion sensor 21 reaches a prescribed value, the heating means is switched off. At that time, prior to the switching-off of the heating means, a part of the exhaust gas is introduced into the cavity 12 according to an opening angle of the control valve 14 for making combustion flame react to oxygen existing in the exhaust gas.</p> |
