| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device which: can reduce pressure loss; has a mixer capable of equally mixing a reducer and exhaust air; and can obtain a high NOx purification rate. SOLUTION: The exhaust emission control device includes: an NOx purification catalyst; a urea water injection device which is provided at an upstream side of the NOx purification catalyst and jets and supplies the reducer; and the mixer 23 which is provided at a downstream side of the urea water injection device and at the upstream side of the NOx purification catalyst, and mixes the reducer jetted by the urea water injection device and the exhaust air. The mixer 23 includes: an outer ring 233 which is fitted around the inner circumference of an exhaust pipe; and a plurality of swirl vanes 235 which are provided on the inner circumferential surface of the outer ring 233 along the circumferential direction with a predetermined space, and which extend from the inner circumferential surface of the outer ring 233 toward a radial direction up to the circumference in the vicinity of the center of the mixer 23 in such a way that the vicinity of the center of the mixer 23 becomes a cavity. The urea water injection device has an injection nozzle which is provided at the position where the jetted reducer hits against the swirl vanes 235. COPYRIGHT: (C)2011,JPO&INPIT |
