| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of preventing an excessive temperature rise of urea water in a urea water tank. <P>SOLUTION: The device is equipped with an ammonia selective reduction type NOx catalyst 40 for selectively reducing NOx by taking ammonia as a reducing agent, a urea water tank 50 storing urea water 54 and including a suction strainer 68 for taking out the stored urea water 54, and a urea water injector 44 including a driving solenoid therein, injecting a part of the urea water taken out of the urea water tank 50 through the suction strainer 68 in upstream side exhaust of the ammonia selective reduction type NOx catalyst 40 and returning the rest of the urea water to the urea water tank 50. In the urea water tank 50, a position of the suction strainer 68 is defined so that the minimum water level of the urea water 54 which can be taken out of the suction strainer 68 becomes a water level for securing a remaining amount of urea water 54 required to keep the temperature of the urea water 54 in the urea water tank 50 not higher than a designated temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT |
