Abstract:
Combustion of hydrocarbon liquids and solids is achieved with less formation of NOx by feeding a small amount of oxygen into the fuel stream.
Abstract:
A overfiring air port of the present invention is to supply an incomplete combustion region with air making up for combustion-shortage, in a furnace in which the incomplete combustion region less than stoichiometric ratio is formed by a burner. Furthermore, the airport is characterized by comprising: a nozzle mechanism for injecting air including an axial velocity component of an air flow and a radial velocity component directed to a center line of the airport; and a control mechanism for controlling a ratio of these velocity components.
Abstract:
The invention relates to a combined fluidized bed and pulverized coal combustion method and system. In the method, fluidizing air (4) is injected into a fluidized bed (2) situated in the bottom portion of the combustion chamber (3). Into the combustion chamber, to above the fluidized bed (2), is fed a mixture of pulverized coal and a carrier gas from a second set of fuel feed means (6) at a mass flow rate which is higher or at least substantially equal to the upper ignition limit of the mixture, and the mixture of the pulverized coal and the carrier gas at least by the fluidizing air (4), and at least a fraction of the fuel fed via the second set of fuel feed means (6) is combusted above the fluidized bed (2).
Abstract:
A method to reduce mercury in gas emissions from the combustion of coal is disclosed. Mercury emissions can be reduced by staging combustion process and/or reducing boiler excess oxygen. Fly ash formed under combustion staging conditions is more reactive towards mercury than fly ash formed under typical combustion conditions. Reducing boiler excess oxygen can also improve ability of fly ash to adsorb mercury.
Abstract:
A tangential fired boiler includes a circumferential wall defining a combustion zone, the circumferential wall being generally rectangular when viewed along a generally horizontal cross-section. A fireball is disposed within the combustion zone, the fireball rotating about an imaginary axis when viewed along a generally horizontal cross-section. A corner member is disposed proximate to at least one corner of the combustion zone, with a plurality of fuel inlets disposed along the corner member. The plurality of fuel inlets inject fuel into the combustion zone, and at least some of the plurality of fuel inlets inject fuel in a direction which is angled with respect to a normal of the corner member and upstream relative to a direction of rotation of the fireball.
Abstract:
There is disclosed a solid fuel boiler including: a furnace including a plurality of solid fuel burners and a furnace wall to perform horizontal firing; a duct through which a part of combustion exhaust gas recirculates to a furnace from a downstream side of the furnace; heat exchanger tubes disposed on a furnace wall and in a heat recovery area of the furnace; and recirculation gas ports via which the recirculation gas is supplied to a reducing flame portion of the burners in the furnace without combining the gas with a flame in the vicinity of an outlet of the burner, so that molten ash is prevented from firmly sticking to the furnace wall and thermal NOx, fuel NOx, and unburned carbon.
Abstract:
A method of extending the droplet half-life of water droplets in a combustion furnace by increasing the relative humidity in the droplets' environment; thereby reducing the evaporation rate of the water from the droplet and increasing the half-life of the droplets in the droplets' environment.
Abstract:
There is disclosed a solid fuel boiler including: a furnace including a plurality of solid fuel burners and a furnace wall to perform horizontal firing; a duct through which a part of combustion exhaust gas recirculates to a furnace from a downstream side of the furnace; heat exchanger tubes disposed on a furnace wall and in a heat recovery area of the furnace; and recirculation gas ports via which the recirculation gas is supplied to a reducing flame portion of the burners in the furnace without combining the gas with a flame in the vicinity of an outlet of the burner, so that molten ash is prevented from firmly sticking to the furnace wall and thermal NOx, fuel NOx, and unburned carbon.
Abstract:
NOx emissions from combustion are reduced, NOx reduction efficiency by SNCR is improved, and other efficiencies are realized, by injecting oxygen into a fuel-rich combustion zone under controlled conditions.
Abstract:
The invention provides a boiler provided with low cost means which can reduce a concentration of CO, an unburned matter, an attached ash and the like near a side wall and maintain a combustion state well with a simple structure. In a boiler having a combustion chamber 13 formed by front and rear walls (burner walls) provided with a plural stages of burners 2, 3 and 4 on at least one of them and opposing to each other, and side walls 1a and 1b crossing to said burner walls 14a and 14b, a gas port 6 containing no fuel for making a pressure of a gas near said side walls 1a and 1b within said combustion chamber 13 higher than a pressure of a gas at a center portion of said combustion chamber 13 is provided between an outermost burner and the side walls 1a and 1b within a range of a height of said burner stages 2, 3 and 4. A combustion gas 16 can not come close to the side walls 1a and 1b due to the jet 18 of the gas.