UREA SOLUTION SPRAYING STRUCTURE

[Problem] To suppress the production of by-products even when SO3 content in exhaust gas is high, or when urea solution is sprayed in a region in which the temperature of the exhaust gas is low. [Solution] A urea solution spraying structure supplies ammonia to an SCR catalyst 6a of a denitrogenation reactor 6 of an exhaust-gas purifying device 7. The denitrogenation reactor 6 is arranged between an exhaust manifold 3 that collects exhaust gas discharged from exhaust connection pipes 2 connected to exhaust ports 1a of an engine 1 and an exhaust pathway 5 upstream of a turbine 4a of a turbo charger 4. The urea solution spraying structure includes an evaporation pipe 10 arranged in the exhaust manifold 3 and connected to a branch pipe 9 branched from an air supply pathway 8 downstream of a compressor 4b of the turbo charger 4, and a nozzle 11 that sprays urea solution in air that passes through the evaporation pipe 10. [Effect] Corrosion and obstruction of the exhaust pathway can be prevented, and performance of the SCR catalyst can be properly maintained.