| 摘要 |
<p>PURPOSE:To burn articulates and remove NOX by disposing NOX reducing catalyst in an exhaust path of an engine and providing a catalyst temperature raising means for maintaining said catalyst at temperature of about 300 deg.C-400 deg.C. CONSTITUTION:In an exhaust path of an engine are provided at least one of Co, Fe and Ni, rate earth elements and a filter 10 coated with NOX recuding catalyst comprising platinum group metal. A catalyst temperature raising means is provided to maintain the reducing catalyst temperature at about 300 deg.C-400 deg.C. The first catalyst temperature raising means controls a throttle valve 25 such that an electromagnetic change-over valve 26 is changed over to control the opening of the throttle valve 25 according to the rotational frequency and load of the engine. The second catalyst temperature raising means controls a heater and when the temperature cannot be raised only by the throttle control, current is supplied to an electric heater 22.</p> |
