| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control system in which effective use of a reducer is achieved, while preventing deposition of its components. <P>SOLUTION: The exhaust emission control system comprises a NO<SB>x</SB>-reduction catalyst 20, a hot plate 28, an electric heater, a supply nozzle 18, and a control unit 24. The NO<SB>x</SB>-reduction catalyst 20 is provided to an exhaust pipe 14 of an engine 10 so as to exert NO<SB>x</SB>-reduction control by a liquid reducer such as urea aqueous-solution. The hot plate 28 is placed on a lower part of the exhaust pipe 14 positioned upstream of the exhaust gas of the NO<SB>x</SB>-reduction catalyst 20. The electric heater is incorporated in the hot plate 28. The supply nozzle 18 supplies the liquid reducer on the top face of the hot plate 28. The control unit 24 controls the electric heater so that plate temperature of the hot plate 28 reaches at least a melting point of the reducer component. The liquid reducer supplied on the top face of the hot plate 28 is actively evaporated and hydrolyzed to prevent deposition of the reducer component, and its effective use is achieved. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
