Patent ID: 6289850
Filing Date: 2001-09-18
Classification: F22B,Y02C

Abstract:
An exhaust heat recovery boiler in which an exhaust gas is discharged into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas so as to reduce nitrogen oxide contained in the exhaust gas, said exhaust heat recovery boiler comprising:a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to a downstream side;a superheater disposed inside the boiler duct at an upstream side of the exhaust gas flow;an evaporator disposed downstream side of the superheater;a denitration reactor disposed downstream side of the evaporator;an economizer disposed downstream side of the evaporator;a drum disposed outside the boiler duct and connected to the evaporator;a downcomer pipe unit extending from the drum to an upstream side of the evaporator inside the boiler duct; andan ammonia injection unit disposed inside the boiler duct for injecting ammonia,said ammonia injection unit being disposed at an upstream side of said evaporator close to said downcomer pipe unit on an upstream side of the downcomer pipe unit.