| 摘要 |
PROBLEM TO BE SOLVED: To efficiently guide a urea aqueous solution to an inner pipe in a urea aqueous solution mixing device using an injector for directly jetting only the urea aqueous solution into an exhaust pipe.SOLUTION: This device includes the exhaust pipe 4B, the injector 5, an inner pipe 7, and a mixing pipe 6. The exhaust pipe 4B comprises an elbow portion 10 which has a curved portion, and a straight portion 11 which is provided on the downstream side of the elbow portion 10. The injector 5, which is provided outside the curved portion of the elbow portion 10, jets only the urea aqueous solution into the elbow portion 10 toward the straight portion 11. The inner pipe 7 is arranged on the exhaust flow downstream side of the injector 5 in the exhaust pipe 4 in such a manner that an inlet portion opening faces the injector 5 and that a space is provided between an outer peripheral surface and an inner wall of the straight portion 11, and exhaust gas can be circulated through the inside and the outer peripheral portion. The mixing pipe 6 guides the urea aqueous solution, which is jetted from the injector 5, to the inner pipe 7. |
