Abstract: In a large exhaust duct from a lean burn combustion source, such as a boiler, diesel engine or gas turbine, multiple injectors can be used to inject a reagent, such as an aqueous solution of urea or ammonia, into the exhaust for use in the catalytic reduction of NOx in a process known in the art as selective catalytic reduction (SCR). When operating at low injection rates, such as during low combustor loads, the injectors are operated individually for short periods of time in a sequential manner.

Abstract: A lean burn combustion source includes a first side stream comprising an inlet and an outlet, both positioned downstream of a furnace and upstream of a particulate control device, and a second side stream comprising: an inlet positioned downstream of the particulate control device and upstream of the catalyst, a heat exchanger section passing through the first side stream, whereby heat from hot exhaust gas flowing through the first side stream is transferred to hot exhaust gas flowing through the second side stream, an injector positioned in the second side stream injecting aqueous based reagent into the hot exhaust gas flowing through the second side stream such that the aqueous based reagent decomposes to ammonia gas, and an outlet in fluid communication with a reagent distribution device positioned in the primary exhaust gas stream downstream of the particulate control device and upstream of the catalyst.

Abstract: A system for controlling reagent flow to an exhaust of a lean burn combustion source includes a plurality of decomposition ducts each being connected to at least one injection lance of a reagent injection grid and supplying reagent and hot carrier gas to the injection lance, and at least one metering valve in communication with each of the plurality of decomposition ducts that controls reagent injection rate to the injection lance. A method of controlling a reagent flow to an exhaust of a lean burn combustion source includes providing a reagent injection grid having at least one injection lance, supplying the reagent and hot carrier gas to the reagent injection grid from a plurality of decomposition ducts coupled to the injection grid, and controlling reagent injection rate to the injection grid via at least one metering valve in communication with each of the plurality of decomposition ducts.

Abstract: In a large exhaust duct from a lean burn combustion source, such as a boiler, diesel engine or gas turbine, multiple injectors can be used to inject a reagent, such as an aqueous solution of urea or ammonia, into the exhaust for use in the catalytic reduction of NOx in a process known in the art as selective catalytic reduction (SCR). When operating at low injection rates, such as during low combustor loads, the injectors are operated individually for short periods of time in a sequential manner.

Abstract: A method of reducing NOx emissions from a lean burn combustion source employs an aqueous solution of reagent that is injected into a continuous decomposition duct at a rate of 0.2-10 gph with a flowing side stream of hot gas at a rate of 150-3000 scfm and a temperature of greater than 700° F. in the decomposition duct such that the aqueous reagent is converted to ammonia gas that is conveyed by the continuous decomposition duct to an ammonia injection grid that is placed in a primary exhaust stream from the combustion source upstream of a NOx reducing catalyst and NOx is reduced.

Abstract: A lean burn combustion source includes a first side stream comprising an inlet and an outlet, both positioned downstream of a furnace and upstream of a particulate control device, and a second side stream comprising: an inlet positioned downstream of the particulate control device and upstream of the catalyst, a heat exchanger section passing through the first side stream, whereby heat from hot exhaust gas flowing through the first side stream is transferred to hot exhaust gas flowing through the second side stream, an injector positioned in the second side stream injecting aqueous based reagent into the hot exhaust gas flowing through the second side stream such that the aqueous based reagent decomposes to ammonia gas, and an outlet in fluid communication with a reagent distribution device positioned in the primary exhaust gas stream downstream of the particulate control device and upstream of the catalyst.

Abstract: A method of reducing NOx emissions from a lean burn combustion source employs an aqueous solution of reagent that is injected into a continuous decomposition duct at a rate of 0.2-10 gph with a flowing side stream of hot gas at a rate of 150-3000 scfm and a temperature of greater than 700° F. in the decomposition duct such that the aqueous reagent is converted to ammonia gas that is conveyed by the continuous decomposition duct to an ammonia injection grid that is placed in a primary exhaust stream from the combustion source upstream of a NOx reducing catalyst and NOx is reduced.

Abstract: A system and method for reducing NOx emissions from a lean burn combustion source is provided. The system includes a blower passing air through a continuous duct having a hot portion and a reaction portion. The hot portion of the duct is positioned in the convective zone of the combustion source to heat the passing air for the reaction portion of the duct. An injector attached to a urea storage container is positioned in the reaction portion of the duct and sprays urea from the storage container into the heated air in the reaction duct for evaporation and decomposition into ammonia gas. The ammonia gas is then supplied to an injection grid in the exhaust duct of the lean burn combustion source upstream of a NOx reduction catalyst. The injection grid supplies the ammonia gas to the exhaust gas in the exhaust duct.

Abstract: A system and method for reducing NOx emissions from a lean burn combustion source is provided. The system includes a blower passing air through a continuous duct having a hot portion and a reaction portion. The hot portion of the duct is positioned in the convective zone of the combustion source to heat the passing air for the reaction portion of the duct. An injector attached to a urea storage container is positioned in the reaction portion of the duct and sprays urea from the storage container into the heated air in the reaction duct for evaporation and decomposition into ammonia gas. The ammonia gas is then supplied to an injection grid in the exhaust duct of the lean burn combustion source upstream of a NOx reduction catalyst. The injection grid supplies the ammonia gas to the exhaust gas in the exhaust duct.

Abstract: A system and method of reducing NOx emissions from a lean burn combustion source is provided. The system includes at least one injection lance having a elongated shaft with distal and proximal ends, a metering valve positioned at the distal end, an atomization chamber positioned between the metering valve and the distal end, a storage chamber for containing a reagent fluidly connected to the metering valve, an injection tip positioned at the proximal end for delivering the reagent, and at least one air port for supplying air to the atomization chamber. The injection lance is positioned in the combustion source, and the reagent is supplied from the storage chamber to the injection lance at an inlet pressure. The reagent is then injected into the combustion source via the injection lance, wherein a temperature of the reagent prior to the injection is maintained below a hydrolysis temperature of the reagent.

Abstract: A system and method of reducing NOx emissions from a lean burn combustion source is provided. The system includes at least one injection lance having a elongated shaft with distal and proximal ends, a metering valve positioned at the distal end, an atomization chamber positioned between the metering valve and the distal end, a storage chamber for containing a reagent fluidly connected to the metering valve, an injection tip positioned at the proximal end for delivering the reagent, and at least one air port for supplying air to the atomization chamber. The injection lance is positioned in the combustion source, and the reagent is supplied from the storage chamber to the injection lance at an inlet pressure. The reagent is then injected into the combustion source via the injection lance, wherein a temperature of the reagent prior to the injection is maintained below a hydrolysis temperature of the reagent.

Abstract: The present invention provides specific design dimensions for a sprayer plate flow restrictor orifices of a fuel oil atomizer, and the resulting arrangement of the atomized liquid spray pattern. Specific depth to diameter ratios of the sprayer plate restrictor orifices and specific dimensions of the chamfer of the inlets to the restrictor orifices of the atomizer of the present invention provide improved performance results as compared to prior art atomizers, including reduced emissions and increased durability of atomizer components.

Abstract: A two phase fuel oil atomizer utilizing a secondary media such as high pressure steam or air to assist in the atomization of heavy fuel oil, while reducing NOx and other polluting emissions. The fuel oil atomizer comprises a mixing plate and a sprayer plate which are configured to discharge atomized fuel oil at varying spray angles in order to provide staging of the atomized fuel as it exits the sprayer plate with the surrounding combustion chamber air to provide a fuel/air ratio that is appropriately rich and lean in order to allow lower flame temperatures. NOx generation is accordingly reduced at the lower flame temperatures. With atomized fuel droplet size small enough to enable rapid fuel evaporation and complete combustion, low CO, opacity and particulate generation are achieved with minimum excess oxygen.

Abstract: The present invention provides specific design dimensions for a sprayer plate flow restrictor orifices of a fuel oil atomizer, and the resulting arrangement of the atomized liquid spray pattern. Specific depth to diameter ratios of the sprayer plate restrictor orifices and specific dimensions of the chamfer of the inlets to the restrictor orifices of the atomizer of the present invention provide improved performance results as compared to prior art atomizers, including reduced emissions and increased durability of atomizer components.

Abstract: A liquid atomizer for, e.g., fuel, comprises a tube having an opening for receiving pressurized liquid flow. The tube has a closed end, a wall, and a plurality of bores in the wall. The bores are disposed in consecutive circumferential rows, and are oriented at an acute angle .alpha. with respect to a radius of the tube and at an acute angle .beta. with respect to a longitudinal axis of the said tube. A shell having a discharge end with a discharge orifice encircles a portion of length of the tube, including the closed end of the tube. The shell forms an annular chamber around the tube end and an end chamber between the closed tube end and the shell discharge end. Liquid under pressure entering the tube opening is directed outwardly through the wall bores into the annular chamber, into the end chamber, and out through the discharge orifice for introduction, for example, into a combustor.

Abstract: A liquid atomizer for, e.g., fuel, comprises a tube having an opening for receiving pressurized liquid flow. The tube has a closed end, a wall, and one or more bores through the wall. A shell having a discharge end with a discharge orifice encircles a portion of length of the tube, including the tube closed end. The shell forms an annular chamber around the tube end and an end chamber between the closed tube end and the shell discharge end. Liquid under pressure entering the tube opening is directed outwardly through the wall bores into the annular chamber, into the end chamber, and out through the discharge orifice for introduction, for example, into a combustor.