| 摘要 |
PURPOSE:To ensure that the content of NOx is reduced and also the volume of black smoke is minimized under a simple structure by providing a device to supply hydrocarbons at a point halfway through a gas suction system and a catalytic converter which activates hydrocarbon component as a reducing agent to decompose NOx at a point halfway through an exhaust gas passage. CONSTITUTION:Hydrocarbons(HC) are ejected in a misty form to a point halfway through an aspiration system 3, using an atomization device 6, then the atomized hydrocarbons are supplied to a combustion chamber 2. After that, the atomized hydrocarbons undergo a separate combustion process from that for fuel which is directly fed to the combustion chamber 2 and unsaturated hydrocarbons which are highly effective for the activation of a catalytic converter 18, are generated. The catalytic converter 18 becomes activated with the unsaturated hydrocarbons as reducing agents to decompose NOx into N2 and O2, and thus performs a reductive catalytic action on NOx. In addition, HC are allowed to become combusted in a precombustion chamber 2 prior to the ejection of fuel from a main fuel injection nozzle 20 by supplying HC to the aspiration system 3. Then, fuel is supplied to the combustion chamber 2 to become ignited. Subsequently, the combustion is accelerated and black smoke in the exhaust gas is minimized to maintain the decomposition effect of the catalytic converter 18. |
