Abstract: A reducing agent supply device for supplying a reducing agent to a portion of a passage for a flue gas upstream of a SCR catalyst includes at least one header pipe extending in the passage and configured to allow the reducing agent to pass through; a plurality of injection nozzles disposed on the header pipe at intervals along an extension direction of the header pipe and configured to inject the reducing agent into the passage; a heat shield plate disposed on an upstream side of the header pipe with respect to a flow direction of the flue gas and having a longitudinal direction along the extension direction of the header pipe; and at least one fixing part contacting each of the heat shield plate and the header pipe and fixing the heat shield plate to the header pipe.

Abstract: A reducing agent supply device for supplying a reducing agent to a portion of a passage for a flue gas upstream of a SCR catalyst includes at least one header pipe extending in the passage and configured to allow the reducing agent to pass through; a plurality of injection nozzles disposed on the header pipe at intervals along an extension direction of the header pipe and configured to inject the reducing agent into the passage; a heat shield plate disposed on an upstream side of the header pipe with respect to a flow direction of the flue gas and having a longitudinal direction along the extension direction of the header pipe; and at least one fixing part contacting each of the heat shield plate and the header pipe and fixing the heat shield plate to the header pipe.

Abstract: This boiler has a flue in which a reducing agent supplying device and a selective reduction catalyst are provided, a bypass flow path bypassing economizers is provided, and a first closing device partially closing the bypass flow path and a second closing device partially closing the flue are also provided. A plurality of first closing members, serving as the first closing device, are provided along the direction in which exhaust gas flows through the flue at a predetermined spacing in the width direction of the flue. A plurality of second closing members, serving as the second closing device are provided along the vertical direction at a predetermined spacing in the width direction of the flue. The first closing members and the second closing members are arranged so as to be displaced from each other in the width direction of the flue.

Abstract: In an exhaust duct and a boiler, there are provided: a flue gas duct through which flue gases pass; a first hopper provided to the flue gas duct, the first hopper collecting PA in the flue gases; a low-repulsion section provided to the upstream side or the downstream side of the first hopper in the direction of flow of the flue gases, the low-repulsion section having a lower coefficient of repulsion than the inner wall surface of the flue gas duct; and a popcorn-ash-trapping section for trapping PA in the flue gases, the popcorn-ash-trapping section provided to the downstream side of the first hopper and the low-repulsion section in the direction of flow of the flue gases, whereby it is possible for solid particles in the flue gases to be properly trapped.

Abstract: This boiler has a flue in which a reducing agent supplying device and a selective reduction catalyst are provided, a bypass flow path bypassing economizers is provided, and a first closing device partially closing the bypass flow path and a second closing device partially closing the flue are also provided. A plurality of first closing members, serving as the first closing device, are provided along the direction in which exhaust gas flows through the flue at a predetermined spacing in the width direction of the flue. A plurality of second closing members, serving as the second closing device are provided along the vertical direction at a predetermined spacing in the width direction of the flue. The first closing members and the second closing members are arranged so as to be displaced from each other in the width direction of the flue.

Abstract: A combustion gas cooling apparatus includes a cooling duct from which a cooling gas at a temperature lower than the temperature of a combustion gas flows out into a mixing duct to form a mixed gas in which the combustion gas and the cooling gas are mixed. The cooling duct has cooling gas flow inlets into which the cooling gas flows, a plurality of cooling gas outflow apertures through which the cooling gas having flowed into the cooling gas flow inlets flows out into the mixing duct, and distribution passages through which the cooling gas having flowed into the cooling gas flow inlets is distributed to the plurality of cooling gas outflow apertures.

Abstract: In an exhaust duct and a boiler, there are provided: a flue gas duct through which flue gases pass; a first hopper provided to the flue gas duct, the first hopper collecting PA in the flue gases; a low-repulsion section provided to the upstream side or the downstream side of the first hopper in the direction of flow of the flue gases, the low-repulsion section having a lower coefficient of repulsion than the inner wall surface of the flue gas duct; and a popcorn-ash-trapping section for trapping PA in the flue gases, the popcorn-ash-trapping section provided to the downstream side of the first hopper and the low-repulsion section in the direction of flow of the flue gases, whereby it is possible for solid particles in the flue gases to be properly trapped.

Abstract: A fuel gas cooling apparatus includes a cooling duct which causes a cooling gas to flow out into a mixing duct, and a difference of maximum dimensions in a height direction of a flow inlet and a flow outlet with respect to a passage length of the mixing duct is smaller than a difference of maximum dimensions in the height direction of a flow inlet and a flow outlet with respect to a passage length of an expanded duct, or a difference of maximum dimensions in a width direction of the flow inlet and the flow outlet with respect to the passage length of the mixing duct is smaller than a difference of maximum dimensions in the width direction of the flow inlet and the flow outlet with respect to the passage length of the expanded duct.

Abstract: The method includes a pretreatment step during an operation of a boiler in which in a predetermined period of time before shutdown of the boiler, a part of combustion gas that has bypassed an economizer provided in a flue gas duct for flue gas from the boiler is supplied to an upstream of a NOx removal device having a NOx removal catalyst and mixed with the combustion flue gas from the economizer to generate mixed gas having a predetermined temperature equal to or higher than 360° C. (360° C. to 450° C.), the mixed gas is introduced into the NOx removal catalyst, thereby decomposing VOSO4 adhering to and accumulating on the NOx removal catalyst into V2O5.

Abstract: A combustion gas cooling apparatus includes a cooling duct from which a cooling gas at a temperature lower than the temperature of a combustion gas flows out into a mixing duct to form a mixed gas in which the combustion gas and the cooling gas are mixed. The cooling duct has cooling gas flow inlets into which the cooling gas flows, a plurality of cooling gas outflow apertures through which the cooling gas having flowed into the cooling gas flow inlets flows out into the mixing duct, and distribution passages through which the cooling gas having flowed into the cooling gas flow inlets is distributed to the plurality of cooling gas outflow apertures.

Abstract: A fuel gas cooling apparatus includes a cooling duct which causes a cooling gas to flow out into a mixing duct, and a difference of maximum dimensions in a height direction of a flow inlet and a flow outlet with respect to a passage length of the mixing duct is smaller than a difference of maximum dimensions in the height direction of a flow inlet and a flow outlet with respect to a passage length of an expanded duct, or a difference of maximum dimensions in a width direction of the flow inlet and the flow outlet with respect to the passage length of the mixing duct is smaller than a difference of maximum dimensions in the width direction of the flow inlet and the flow outlet with respect to the passage length of the expanded duct.

Abstract: The method includes a pretreatment step during an operation of a boiler in which in a predetermined period of time before shutdown of the boiler, a part of combustion gas that has bypassed an economizer provided in a flue gas duct for flue gas from the boiler is supplied to an upstream of a NOx removal device having a NOx removal catalyst and mixed with the combustion flue gas from the economizer to generate mixed gas having a predetermined temperature equal to or higher than 360° C. (360° C. to 450° C.), the mixed gas is introduced into the NOx removal catalyst, thereby decomposing VOSO4 adhering to and accumulating on the NOx removal catalyst into V2O5.

Abstract: The method includes a pretreatment step during an operation of a boiler in which in a predetermined period of time before shutdown of the boiler, a part of combustion gas that has bypassed an economizer provided in a flue gas duct for flue gas from the boiler is supplied to an upstream of a NOx removal device having a NOx removal catalyst and mixed with the combustion flue gas from the economizer to generate mixed gas having a predetermined temperature equal to or higher than 360° C. (360° C. to 450° C.), the mixed gas is introduced into the NOx removal catalyst, thereby decomposing VOSO4 adhering to and accumulating on the NOx removal catalyst into V2O5.

Abstract: The method includes a pretreatment step during an operation of a boiler in which in a predetermined period of time before shutdown of the boiler, a part of combustion gas that has bypassed an economizer provided in a flue gas duct for flue gas from the boiler is supplied to an upstream of a NOx removal device having a NOx removal catalyst and mixed with the combustion flue gas from the economizer to generate mixed gas having a predetermined temperature equal to or higher than 360° C. (360° C. to 450° C.), the mixed gas is introduced into the NOx removal catalyst, thereby decomposing VOSO4 adhering to and accumulating on the NOx removal catalyst into V2O5.