| 摘要 |
PROBLEM TO BE SOLVED: To provide a urea aqueous solution mixing device which can properly mix a urea aqueous solution and exhaust gas together and which restrains the urea aqueous solution from adhering to an inner wall of an exhaust pipe.SOLUTION: This device includes the exhaust pipe 4B, an injector 5, a mixing pipe 6, and an inner pipe 7. 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, emits a jet of urea aqueous solution to the straight portion 11. The mixing pipe 6 is arranged in such a manner as to cover the periphery of the urea aqueous solution jetted from the injector 5, inside the elbow portion 10, and has a plurality of openings 6a on an outer peripheral surface. The inner pipe 7, which is arranged with a space between itself and an outlet portion of the mixing pipe 6 on the downstream side of the mixing pipe 6 and with a space between itself and the inner wall of the straight portion 11, enables the exhaust gas to be circulated through its inside and outer peripheral portion. |
