摘要:
A burner for the combustion of a pulverized coal plus primary air mixture includes a nozzle pipe having an inlet for receiving a pulverized coal plus primary air mixture and an outlet for discharging same. A hollow plug extends axially within the nozzle pipe and defines an annular space between the plug and the nozzle pipe for conveying the pulverized coal plus primary air mixture therethrough. The hollow plug is axially moveable within the nozzle pipe. A variable amount of core air is supplied into the hollow plug so that it mixes with the primary air plus pulverized coal mixture at an outlet of the burner to vary the PA/PC ratio and maintain a desired primary air to primary coal ratio at the outlet of the burner. Natural gas can also be supplied into the hollow plug as a supplemental fuel for cofiring at the outlet end of the burner. The amount of core air supplied is based upon (1) the coal flow rate being provided to the burner, in lb/hr, and (2) the percent volatile matter content (%VM) in the coal being burned.
摘要:
A dual fuel burner including an elongated supply pipe and a gas injector for a boiler furnace having a plurality of peripheral openings around a center opening. The peripheral openings are pitched radially away from the longitudinal axis of the gas injector and also pitched either clockwise or counter-clockwise, to impart a swirling motion to gaseous fuel exiting the injector through the openings. A first sleeve member is concentrically spaced about the supply pipe and the gas injector to form an inner annular passageway for conveying a mixture of primary air and pulverized coal to the furnace combustion zone. A second sleeve member is concentrically spaced about the first sleeve member to form an outer annular passageway for conveying secondary air to the furnace combustion zone, and a plurality of circumferentially spaced vanes mounted within the outer annular passageway for inducing a swirling motion to the secondary air discharging from the outer annular passageway into the furnace combustion zone.
摘要:
An air premixed natural gas burner having reduced thermal and prompt NO.sub.x emissions employs a central, cylindrical core chamber and an outer annular chamber separated by a hollow barrel having a plurality of gas spuds at a front end of the burner adjacent to a burner throat. The plurality of gas spuds introduces natural gas into a core chamber air flow passing through a fixed swirler and controlled by a sliding air flow damper associated with the central, cylindrical core chamber. A reduced air/fuel stoichiometric ratio (of approximately 0.6) is preferably maintained at an outlet of the central, cylindrical core chamber. The balance of the combustion air is provided through the outer annular chamber to maintain an overall or cumulative burner stoichiometric ratio of approximately 1.05.
摘要:
A method is disclosed for reducing the NOx emission of fossil fuel burners. The method creates fuel-rich and fuel-lean zones within the boiler to enhance the removal of NOx species by creating a plurality of NOx reducing precursors.
摘要:
A large diameter mid-zone air separation cone is provided for decreasing NOx during burner operation by expanding the internal recirculation zone (IRZ) at the burner exit. The mid-zone air separation cone has a short cylindrical leading edge that fits in the outer air zone of a burner. The mid-zone air separation cone splits the outer air zone secondary air flow into two equal or unequal streams depending on the position of the air separation cone with respect to the outer air zone, and deflects a portion of the secondary air flow radially outward. Since the radial position of the air separation cone is farther from the burner centerline, the IRZ size is expanded and NOx emissions are minimized.
摘要:
A burner having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO.sub.x burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO.sub.x back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing.
摘要:
A method and apparatus for reducing NOx emissions in a coal burning furnace of a power plant without utilizing techniques downstream of the furnace, such as SCR and SNCR, is provided. In a primary combustion zone, a fuel is combusted in the presence of a first oxidant gas comprised substantially of N2, to produce a first effluent gas that include one or more NOx species. Downstream a re-burn zone is operated in a sub-stoichiometric manner, combusting a second fuel in presence of the first effluent gas and a second oxidant wherein the second oxidant gas comprises a stream of oxygen. The effluent gas from the re-burn zone is introduced to overfire airflow so as to establish a super-stoichiometric zone prior to discharged from the furnace.
摘要:
A new burner apparatus and method of combusting fossils fuels for commercial and industrial application is provided wherein the new burner apparatus achieves low NOx emissions by supplying oxygen to the center of the burner flame in as manners so as to create a fuel rich internal combustion zone within the burner flame.
摘要:
A method is disclosed for reducing the NOx emission of fossil fuel burners. The method creates fuel-rich and fuel-lean zones within the boiler to enhance the removal of NOx species by creating a plurality of NOx reducing precursors.
摘要翻译:公开了一种用于减少化石燃料燃烧器的NO x排放的方法。 该方法在锅炉内产生富燃料和无燃料的区域,以通过产生多个NO x X 3还原前体来增强NO x 2物质的去除。