摘要:
Emissions of NOx and CO are reduced from combustion devices such as coal-fired furnaces by increasing the stoichiometric ratio of burner(s) having a lower average temperature and increasing the stoichiometric ratio of burner(s) having a higher average temperature.
摘要:
Emissions of NOx and CO are reduced from combustion devices such as coal-fired furnaces by increasing the stoichiometric ratio of burner(s) having a lower average temperature and increasing the stoichiometric ratio of burner(s) having a higher average temperature.
摘要:
A burner assembly cofires a primary solid fuel and a secondary solid fuel in a combustion zone of a boiler. The burner assembly includes a fuel injector that mixes the primary solid fuel and the secondary solid fuel prior to injection into the combustion zone of the boiler. The primary solid fuel may be pulverized coal, pulverized petroleum coke, or the like, while the secondary solid fuel may be a biomass fuel or refuse-derived fuel.
摘要:
Improved operational characteristics such as improved fuel efficiency, reduction of NOx formation, reduction of the amount of unburned carbon in the ash, and lessened tendency to corrosion at the tube wall, in a multi-burner furnace are obtained by reducing the flow rate of combustion air to the burners and selectively individually feeding oxidant to only some of the burners.
摘要:
Improved operational characteristics such as improved fuel efficiency, reduction of NOx formation, reduction of the amount of unburned carbon in the ash, and lessened tendency to corrosion at the tube wall, in a multi-burner furnace are obtained by reducing the flow rate of combustion air to the burners and selectively individually feeding oxidant to only some of the burners.
摘要:
A method for reducing NOx emissions from the combustion of carbonaceous fuels using three stages of oxidation and second stage in-situ furnace flue gas recirculation. In the first stage, a partial oxidation combustor is used to partially combust the fuel in the presence of preheated combustion air. The fuel gas produced in the partial oxidation process is passed to a second stage partial oxidation combustor while molten slag is removed and disposed of. Preheated combustion air also is introduced into the second stage of combustion to produce a slightly reducing flue gas and is injected into the furnace in such a way as to create the desired in-situ furnace flue gas recirculation. In the upper part of the furnace a third combustion air is mixed with the flue gas in a third stage of combustion to substantially complete the combustion process. Preheated steam may be added to the first or second stages of combustion. The stoichiometric ratios at each stage of combustion are controlled to minimize overall NOx emissions to acceptable levels. Further, an existing excess air cyclone-fired boiler furnace may be modified to operate in a three-stage combustion mode. This is accomplished by adding a preheated air system that includes two added air injection points into the furnace, with air introduction at a cyclone barrel re-entrant throat that is located at the interface between the cyclone barrel and the furnace, followed by overfire air introduction into the upper part of the furnace.
摘要:
Oil shale having a relatively wide range of heating value is combusted by supplying the oil shale and a further fuel having a heating value greater than the heating value of the oil shale to a combustor. The oil shale is fed to the combustor at a substantially fixed rate, independently of the heating value of the oil shale, and the further fuel is fed to the combustor at a rate such that the heating value of the fuel in the combustor remains substantially constant in the face of variations in the heating value of the oil shale. Preferably, the temperature of combustion of the products of combustion is the parameter used to control the rate at which the further fuel is fed to the combustor.
摘要:
A combustion apparatus includes a combustion chamber having multiple combustion zones. A first wind box is in communication with the first combustion zone to feed the fuel to be fed into the combustion chamber for initial combustion of the fuel within the first combustion zone. A second wind box has a reburner in communication with the second combustion zone. The reburner is configured to feed fuel, a reagent and a first portion of the flue gas to be recycled to the second combustion zone into the second combustion zone to reduce nitrogen oxide emissions of the apparatus. A third wind box is in communication with the third combustion zone to feed air to the third combustion zone to complete the combustion process.
摘要:
A combustion system and method for operating a combustion system, such as a furnace or boiler. The method includes providing a burner system having one or more burner elements configured to combust solid fuel and one or more oxygen providing devices configured to introduce oxygen into the near burner zone of one or more burner flames. A sensor is provided and arranged and disposed to measure a flame parameter in the near burner zone of the burner flame associated with one or more the burner elements. The flame parameter is measured with the sensor and an oxygen flow is determined in response to the measured flame parameter. Oxygen flow is introduced to one or more locations in the combustion system with the one or more oxygen providing devices.