| 摘要 |
PROBLEM TO BE SOLVED: To provide a urea injection device capable of avoiding jamming due to crystallization of urea water in injection of the urea water by using a urea water injection nozzle for simultaneously injecting the urea water and the air.SOLUTION: A urea injection device comprises: a urea water injection nozzle 21 for simultaneously injecting urea water and the air to an exhaust pipe; a urea pump 23 connected with a urea water tank 22 via a urea water suction pipe 31 and for supplying the urea water to the urea water injection nozzle 21 via a urea water discharge pipe 32; a urea valve 25 connected with the urea water suction pipe 31; an air pump 24 for supplying the air to the urea water injection nozzle 21 through an air supply pipe 33; an air sweeping pipe 34 for connecting the air supply pipe 33 with the urea water discharge pipe 32; an air valve 26 connected with the air sweeping pipe 34; and a controller 30 for stopping the urea pump 23 in stop of injection, opening the air valve 26 after holding the state to sweep the inside of the urea water discharge pipe 31 with the air, and after that stopping the air pump 24.SELECTED DRAWING: Figure 1 |
