AQUEOUS UREA SPRAYING STRUCTURE

PROBLEM TO BE SOLVED: To suppress generation of a byproduct even when a ratio of SOcontained in exhaust gas is high or even when aqueous urea is sprayed in a reduced exhaust gas temperature region.SOLUTION: An aqueous urea spraying structure is capable of supplying ammonia to an SCR catalyst 6a of a denitration reactor 6 of an exhaust emission control system 7 including the denitration reactor 6 provided between an exhaust manifold 3 that collects the exhaust gas discharged from an exhaust connection pipe 2 connected to an exhaust port 1a of an engine 1 and an exhaust pathway 5 upstream of a turbine 4a of a turbocharger 4. An evaporation tube 10 connected to a branching pipe 9 branching from an gas supply pathway 8 downstream from the compressor 4b of the turbocharger 4 is disposed in the exhaust manifold 3 and a nozzle 11 for spraying the aqueous urea to air passing through the evaporation tube 10 is provided in the evaporation tube. The corrosion or occlusion of the exhaust pathway is prevented and favorable SCR catalyst performance can be maintained.