REDUCING AGENT AQUEOUS SOLUTION MIXING DEVICE AND EXHAUST GAS AFTER-TREATMENT DEVICE

摘要

The present invention suppresses adhesion of a urea aqueous solution to an interior wall of an exhaust pipe and reduces flow resistance inside the exhaust pipe, in a urea aqueous solution mixing device. This urea aqueous solution mixing device is provided with an exhaust pipe (4B), an injector (5), a mixing pipe (6), an interior pipe (7), and a flow unit (20). The exhaust pipe (4B) has an elbow part (10) with a curved section, and a straight part (11). The injector (5) injects the urea aqueous solution, and is provided in the elbow part (10). The mixing pipe (6) is positioned so as to cover the area around the urea aqueous solution injected by the injector (5), and has an exit part formed between the interior walls of the exhaust pipe (4B) with an interval interposed therebetween, and a plurality of openings (6a) formed in the outer-peripheral surface thereof. The interior pipe (7) allows exhaust gas to flow through the interior and outer-peripheral sections thereof, and is positioned in the straight part (11) of the exhaust pipe (4B). The flow unit (20) guides exhaust gas into the interior pipe (7), and is formed between the exit part of the mixing pipe (6) and the interior walls of the exhaust pipe (4B).