AQUEOUS UREA-SPRAYING STRUCTURE

摘要

[Problem] To limit the generation of by-products even when the proportion of SO3 contained in the exhaust gas is high or when the aqueous urea is sprayed in a reduced exhaust gas temperature region. [Solution] An aqueous urea-spraying structure capable of supplying ammonia to an SCR catalyst (6a) of a denitrogenation reactor (6) of an exhaust gas-cleaning device (7) equipped with a denitrogenation reactor (6) provided between an exhaust manifold (3) that collects exhaust gas exhausted from exhaust connection tubes (2) that are connected to the exhaust ports (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 a gas supply pathway (8) downstream from the compressor (4b) of the turbocharger (4) is disposed inside the exhaust manifold (3) and a nozzle (11) that sprays aqueous urea into the air passing through the evaporation tube (10) is provided. [Effect] The present invention prevents corrosion and occlusion of the exhaust pathway and is also able to maintain favorable SCR catalyst performance.