| 摘要 |
PROBLEM TO BE SOLVED: To provide a urea aqueous solution mixing device in which flow path resistance in an exhaust pipe is reduced by restraining a urea aqueous solution from adhering to an inner wall of the exhaust pipe.SOLUTION: The urea aqueous solution mixing device includes the exhaust pipe 4B, an injector 5, a mixing pipe 6, an inner pipe 7, and a circulation portion 20. The exhaust pipe 4B comprises an elbow portion 10 having a curved portion, and a straight portion 11. The injector 5, which is provided in the elbow portion 10, emits a jet of urea aqueous solution. The mixing pipe 6 comprises an outlet portion which is arranged in such a manner as to cover the periphery of the urea aqueous solution jetted from the injector 5 and which is formed with a space between itself and the inner wall of the exhaust pipe 4B, and a plurality of openings 6a which are formed on an outer peripheral surface. The inner pipe 7, which is arranged in the straight portion 11 of the exhaust pipe 4B, enables exhaust gas to be circulated through its inside and outer peripheral portion. The circulation portion 20, which is formed between the outlet portion of the mixing pipe 6 and the inner wall of the exhaust pipe 4B, guides the exhaust gas to the inner pipe 7. |
