Abstract: A non-bypassable catalyst assisted appliance includes, for example, a housing having a combustion chamber, a loading door, an air inlet opening, and an exit opening connectable to a flue. A platform defines a non-movable separation in the housing between the combustion chamber and the exit opening. An insulated catalyst combustor is disposed between a top wall of the housing and the platform. When the door of the appliance is closed, gas from the combustion chamber is exhausted and directed along a single flow path horizontally through the insulated catalytic combustor and into the flue. When the door of the appliance is open, gas from the combustion chamber is inhibited from passing through the loading door opening, and ambient air entering the loading door opening and combustion gas from the combustion chamber are exhausted and directed along a single flow path horizontally through the insulated catalytic combustor and into the flue.

Abstract: Integration of an oxyfuel combustion boiler at elevated pressures and a heat exchanger is achieved to produce carbon dioxide by feeding flue gas comprising carbon dioxide and water from the oxyfuel combustion boiler to a direct contact cooler column wherein water is condensed at a temperature of 0 to 10° C. lower than its dew point; feeding a portion of the condensed water from the direct contact cooler column to the oxyfuel combustion boiler; feeding a portion of the carbon dioxide from the direct contact cooler column to the oxyfuel combustion boiler; and recovering a portion of the carbon dioxide from the direct contact cooler column.

Abstract: A fuel-fired heating appliance comprises a burner and a first housing adjacent the burner so that an interior of the first housing receives combustion gasses from combustion at the burner. A heat exchanger defines a second housing with an inlet proximate an outlet of the first housing so that the inlet of the second housing receives combustion gasses from the outlet of the first housing, and wherein the first and second housings attach at an interface. A barrier extends within, and across an interface between, the outlet of the first housing and the inlet of the second housing and defines a thermal resistance that inhibits heat transfer from the combustion gasses to the interface.

Abstract: A method and system for improving high excess air combustion system efficiency, including induration furnaces, using a re-routing of flue gas within the system by gas recirculation. Flue gas is drawn from hot system zones including zones near the stack, for re-introduction into the process whereby the heat recovery partially replaces fuel input. At least one pre-combustion drying zone, at least one combustion zone, and at least a first cooling zone exist in these furnaces. At least one exhaust gas outlet is provided to each pre-combustion drying and combustion zone. At least part of the gaseous flow from each system zone exhaust outlet is selectively delivered to an overall system exhaust, the remaining flow being selectively delivered via recirculation to cooling zones. Recirculation flow is adjusted to meet required system temperatures and pressures. The method and system provide efficiency improvements, reducing fuel requirements and greenhouse gas emissions.

Abstract: Exemplary embodiments or implementations are disclosed of methods, apparatus, and systems for operating motors in variable speed situations. In an exemplary implementation, a method of controlling a variable-speed motor includes defining a control duration as a predetermined number of cycles of a multiple-phase power supply. Each speed in a range of speeds is defined by a corresponding number of the cycles of the control duration. Power is provided to the motor from the power supply at a selected one of the speeds, by enabling input from the power supply for the number of the cycles of the control duration corresponding to the selected speed.

Abstract: A precombustor system (300) including an ignition chamber (301) having a front wall (308), a central axis, a diameter Dic, and an outlet (313) configured to discharge a product gas (315). The ignition chamber (301) includes a central ignition oxygen injector (307) configured to inject a first oxygen stream from the front wall (308) substantially parallel to the central axis, and a tangential primary fuel injector (303) configured to inject a primary fuel stream tangential to the central axis at a location an axial distance Xpf downstream of the front wall (308). The ratio Xpf/Dic is from 0.25 to 4.0. The central axis forms an angle a with a vertical line of less than or equal to about 45 degrees. The trajectory of the primary fuel stream forms an angle ? with a plane that is perpendicular to the central axis of less than or equal to about 20 degrees. A method for combustion is also disclosed.

Abstract: A burner has a fuel/oxidant nozzles and a pair of dynamical lances spaced on either side thereof that inject a jet of fuel and primary oxidant along a fuel injection axis, and jets of secondary oxidant, respectively. Jets of actuating fluid impinge against the jets of secondary oxidant to fluidically angle the jets of secondary oxidant away from the fuel injection axis. The action of the angling away together with staging of the oxidant between primary and secondary oxidant injections allows achievement of distributed combustion conditions.

Abstract: A grid for distributing and mixing fluids in a duct includes a plurality of lances arranged in a first plane and configured to be positioned transverse to a direction of a first fluid flowing outside of the lances and within a predetermined flow area. Each of the plurality of lances has at least one first inlet and a plurality of outlet nozzles. One or more of the outlet nozzles is directed generally in the flow direction of the first fluid outside of the lances, and is configured to discharge a second fluid therefrom.

Abstract: In an oxygen mixer for an oxygen combustion boiler, circulating exhaust gas heated in a rotary preheater is mixed with oxygen. Resultant mixed gas is guided to a boiler furnace through a combustion gas duct having bends. At the bend closest to the rotary preheater in the combustion gas duct, an oxygen injection nozzle is arranged to have a plurality of injection ports for injection of oxygen into circulating exhaust gas.

Abstract: The invention relates to a combustion apparatus, in particular to a burner for the combustion of carbonaceous fuel.

Abstract: The leakage reduction system includes a heat exchanger, a duct arrangement and a separation arrangement. The heat exchanger includes a rotor assembly rotatably mounted along a rotor post. The heat exchanger further includes a second inlet plenum, whereat the duct arrangement is configured. Further, the separation arrangement is incorporated at the duct arrangement dividing thereto into primary and secondary inlets. Through the primary inlet, a flue gas enriched with Oxygen is carried, and through the secondary inlet a recycled flue gas flow is allowed to be carried, keeping the Oxygen enriched recycled flue gas flow substantially away from turnover towards the flue gas flow to avoid turnover towards a flue gas flow, reducing leakage thereof.

Abstract: In one aspect, a combustion system is configured to facilitate preventing the formation of vanadium pentoxide (V2O5) and decrease a concentration of at least one of vanadium trioxide (V2O3) and vanadium tetroxide (V2O4) particles in an exhaust. The combustion system includes a vanadium-containing fuel supply and a combustor. The combustor is configured to generate a combustor exhaust gas including vanadium trioxide (V2O3) and/or vanadium tetroxide (V2O4) particles and to combust a reduced-oxygen mixture including the vanadium-containing fuel, ambient air, and a portion of the combustor exhaust gas. The combustion system also includes a particle separator configured to remove substantially all of the V2O3 and/or V2O4 particles from the combustor exhaust gas. A method for combusting fuel and a power generation system are also provided.

Abstract: An air infiltration abatement system (300) for a power plant (10) includes a recirculated flue gas source (175), a recirculated flue gas supply line (310) connected to the recirculated flue gas source (175) and a power plant component. The power plant component has a leakage area in fluid communication with the recirculated flue gas supply line (310). The recirculated flue gas source (175) receives a combustion flue gas (75) from an oxygen fired boiler (20) of the power plant (10), and provides the combustion flue gas (75) to the recirculated flue gas supply line (310). The recirculated flue gas supply line (310) supplies the combustion flue gas (75) as a recirculated flue gas (330) to the oxygen fired boiler (20) via the leakage area of the power plant component.

Abstract: The invention refers to a forced flow steam generator (10) and to a method for its operation. The forced flow steam generator (10) has a combustion chamber (11) with a burner arrangement (20). A fuel (B) and a mixture (G) consisting of pure oxygen and flue gas (R) are fed into the combustion chamber (11) or to the burner arrangement (20) for combusting. A flue gas duct (27) is connected to the combustion chamber (11) in the flow direction (S) of the flue gas (R), and a flue gas passage (26) is connected to the flue gas duct. The flue gas (R) for the oxygen-flue gas mixture (G) is fed back from the flue gas passage (26) via a flue gas recirculation line (28). The forced flow steam generator (10) is operated in the so-called oxyfuel process. A plurality of auxiliary heating surfaces (35) are arranged in the flue gas duct (27) downstream of the burner arrangement (20).

Abstract: A system for providing combustion air and fuel gas to a premix burner includes a premix engine, a premix burner in fluid communication with an outlet of the premix engine, an exhaust flue, a flue gas recirculation line in fluid communication with the flue and an inlet of the premix engine, and a fresh air line in fluid communication with a source of fresh air and the inlet of the premix engine. A flue gas flow restrictor is installed in the flue gas recirculation line, and a fresh air flow restrictor is installed in the fresh air line. The flow restrictors are sized so that the premix engine, in operation, draws recycled flue gas and fresh air from the recycled flue gas line and fresh air line, respectively, in a predetermined proportion.

Abstract: In an apparatus of controlling an exhaust gas in an oxyfuel combustion boiler having the boiler 4 provided with burners 6 and a two-stage combustion port 7, a primary recirculation line 12 through which pulverized coal obtained by a mill 3 is fed to the burners 6 of the boiler 4 by the primary recirculating exhaust gas, a secondary recirculation line 14 through which another portion of the exhaust gas in recirculation is fed to a wind box 5 of the boiler 4, an oxygen producer 23, a direct supply line 25 through which a portion of oxygen produced by the oxygen producer 23 is directly fed to the burner 6 and a secondary oxygen mixing line 24 through which another portion of oxygen produced by the oxygen producer 23 is fed to the secondary recirculation line 14, the apparatus comprises an oxygen supply line 26 through which oxygen is fed to the two-stage combustion port of the boiler 4 and a flow rate regulator 20, 27 in the oxygen supply line for adjusting oxygen density.

Abstract: The burner device for high-temperature air combustion according to the present invention is equipped with a thermal insulation portion (5) that is provided facing a furnace (1) and has a throat (6); a burner nozzle (9) that is provided at the axial center of this throat and that injects a pulverized coal mixed flow (38) into the furnace through the throat; a windbox (8) that is provided so as to house this burner nozzle; an air register (16) that is provided at the distal end of the burner nozzle and that injects low-temperature secondary air from the windbox to the throat; a high-temperature air nozzle (23), one end of which opens into the furnace through the heat insulation portion; and a combustion air switching means (16, 24) that switches between injecting low-temperature secondary air to the throat through the air register and injecting high-temperature secondary air to the furnace interior through the high-temperature air nozzle, in which in steady combustion, low-temperature secondary air is injected

Abstract: An oxyfuel combustion boiler plant comprising: an air separation unit for manufacturing oxygen by separating nitrogen from air, a boiler having a burner for burning the oxygen supplied from the air separation unit and pulverized coal, and a primary system pipe for supplying the pulverized coal to the burner, an exhaust gas recirculation system pipe for supplying combustion exhaust gas discharged from the boiler to the primary system pipe, and a carbon dioxide capture unit for capturing carbon dioxide in the exhaust gas discharged from the boiler, the oxyfuel combustion boiler plant is further comprising: an oxygen supply pipe for supplying the oxygen manufactured by the air separation unit to the primary system pipe in the burner, and a pipe for supplying the combustion exhaust gas discharged from the boiler to the oxygen supply pipe, wherein an injection port of the oxygen supply pipe is disposed on an upstream side of an injection portion of the burner.

Abstract: An oxygen combustion system includes a boiler to burn fuel using combustion gas composed of oxygen-rich gas and circulating flue gas, a dust remover disposed in a flue through which flue gas discharged from the boiler flows, a second flue leading the combustion gas to the boiler, the combustion gas being made by mixing the circulating flue gas extracted downstream of the dust remover with the oxygen-rich gas, a combustion gas heater exchanging heat between the flue gas flowing between the boiler and dust remover and the combustion gas flowing through the second flue, and a flue gas cooler disposed between the heater and the dust remover to cool the flue gas. A control unit controls at least one of a flow rate and cooling medium temperature of the flue gas cooler such that temperature of the flue gas introduced into the dust remover will be between 90° C. and 140° C.

Abstract: A boiler operating method operates a boiler by switching between air combustion mode and oxygen combustion mode when burning fossil fuel with first combustion gas and second combustion gas. The second combustion gas compensates for oxygen deficiency in the first combustion gas. The air combustion mode uses air as the first combustion gas and the second combustion gas while the oxygen combustion mode uses mixed gas of combustion flue gas and oxygen-rich gas as the first combustion gas and the second combustion gas, the combustion flue gas being produced when the fossil fuel is burned. By mixing the oxygen-rich gas in the air in the process of switching between air combustion mode and oxygen combustion mode, the air being the first combustion gas used in the air combustion mode, the boiler operating method can switch between the air combustion mode and oxygen combustion mode while maintaining stable combustion.

Abstract: A fired heater includes a fired heater body with an air inlet and a flue gas outlet, and a flue gas waste heat recovery system communicated with the fired heater body and including at least two heat exchange chambers. A first port of each of the heat exchange chambers can be communicated with the flue gas outlet or the air inlet, and a second port of each of the heat exchange chambers can be communicated with the outside air or a fume extractor. When the first port of at least one heat exchanger chamber is communicated with the flue gas outlet and the second port thereof is communicated with the fume extractor, the first port of at least another heat exchange chamber is communicated with the air inlet and the second port thereof is communicated with the outside air.

Abstract: To inhibit corrosion of water wall tubes of a boiler and stabilize combustion on a burner during oxygen combustion operation, a boiler combustion system includes a boiler equipped with a burner and a two-staged combustion gas input port; a flue gas supply fan extracting flue gas from a flue gas treatment system via a flue gas circulation line; a combustion gas supply line, fuel carrier gas supply line, and two-staged combustion gas supply line branched off from the flue gas circulation line downstream of the flue gas supply fan; an oxygen supply line supplying oxygen-rich gas to the combustion gas supply line and fuel carrier gas supply line; combustion air supply fans; a switching unit switching operation between the flue gas supply fan and the combustion air supply fans; and dampers regulating gas flow rates on the combustion gas supply line and the two-staged combustion gas supply line, respectively.

Abstract: An oxygen combustion system includes a boiler to burn fuel using combustion gas composed of oxygen-rich gas and circulating flue gas, a dust remover disposed in a flue through which flue gas discharged from the boiler flows, a second flue leading the combustion gas to the boiler, the combustion gas being made by mixing the circulating flue gas extracted downstream of the dust remover with the oxygen-rich gas, a combustion gas heater exchanging heat between the flue gas flowing between the boiler and dust remover and the combustion gas flowing through the second flue, and a flue gas cooler disposed between the heater and the dust remover to cool the flue gas. A control unit controls at least one of a flow rate and cooling medium temperature of the flue gas cooler such that temperature of the flue gas introduced into the dust remover will be between 90° C. and 140° C.

Abstract: An oxyfuel combustion boiler plant comprising: a boiler having an air separation unit for manufacturing oxygen by separating nitrogen from air, a burner for burning the oxygen supplied from the air separation unit and pulverized coal, and a primary system pipe for supplying the pulverized coal to the burner, exhaust gas recirculation system pipe for supplying combustion exhaust gas discharged from the boiler to the primary system pipe, a carbon dioxide capture unit for capturing carbon dioxide in the exhaust gas discharged from the boiler, the oxyfuel combustion boiler plant is further comprising: an oxygen buffer tank disposed on a downstream side of the air separation unit; an oxygen supply pipe for supplying oxygen to the primary system pipe of the burner from the oxygen buffer tank; and a nitrogen supply pipe for supplying a part of nitrogen generated from the air separation unit or an air supply pipe for supplying air from outside which is connected to the oxygen supply pipe on a downstream side of the

Abstract: A device and method for producing a fine-grained fuel, in particular from solid, paste-like or aqueous energy feed stocks, by drying and crushing, including an impact reactor having a rotor and impact elements, a labyrinth seal in the region of the rotor shaft of the impact reactor, a device for feeding hot drying gas through the labyrinth seal into the impact reactor and at least one further feed device for hot drying gas in the bottom region of the impact reactor, a feed device for solid or paste-like energy feed stocks in the top region of the impact reactor, at least one extractor device for a gas flow containing crushed and dried energy feedstock particles, and a device for separating and extracting crushed and dried energy feed stock particles from the gas flow extracted from the impact reactor.

Abstract: Provided are fuel feed means 3, an air separation unit 6 air feed means 7, a combustion furnace 11 with a burner 9 for combustion, an exhaust gas line 14 for leading an exhaust gas from the combustion furnace 11 to outside of the combustion furnace 11, exhaust gas treatment means 20a and 20b included in the exhaust gas line 14, and a recirculation line 15 for circulating a portion of the exhaust gas at least exhaust gas treatment means 20a and 20b for recirculation of a portion of the exhaust gas at least dust-removed by the exhaust gas treatment means 20a and 20b to the burner. Further provided are exhaust gas capture means 18 for taking out carbon dioxide gas from a remaining non-recirculating exhaust gas, and carbon dioxide gas feed means 33, 40 and 46 for introducing carbon dioxide gas to equipments 10, 20a and 20b of the oxyfuel combustion boiler facility.

Abstract: A gas cleaning system (8) for cleaning a carbon dioxide rich flue gas containing sulphur dioxide generated in a boiler (2) comprises a first gas cleaning device (10) being operative for removing at least 80% of the sulphur dioxide content of the flue gas generated in the boiler (2), thereby generating a partly cleaned carbon dioxide rich flue gas, and a second gas cleaning device (12), being separate from the first gas cleaning device (10) and being operative for receiving at least a portion of the partly cleaned carbon dioxide rich flue gas that passed through the first gas cleaning device (10). The second gas cleaning device (12) is operative for removing at least a portion of the water content of the partly cleaned carbon dioxide rich flue gas by means of cooling the partly cleaned carbon dioxide rich flue gas to condense water there from.

Abstract: A process for combusting solid liquid or gaseous fuels in a high temperature refractory-lined reactor with the aim of generating electric power comprises mixing at least one fuel with steam. The refactory material of the reactor and the opaque gases of the reaction environment bring about high power infrared radiation which substantially instantaneously preheats the reactants on input including said reactants being intrinsically transparent to infrared radiation (N2/O2) but rendered opaque and thus absorbers of energy from infrared radiation thanks to dilution with steam. A high efficiency combustor is provided for carrying out the above-stated process.

Abstract: An improved burner and a method for combusting fuel used in furnaces such as those found in steam cracking. The burner includes a burner tube having a downstream end and an upstream end, a burner tip adjacent a first opening in the furnace, so that combustion of the fuel takes place at the burner tip, a lighting chamber adjacent to the first opening in the furnace, and a removable lighting chamber plug having a shape effective to substantially fill the lighting chamber when positioned within the lighting chamber.

Abstract: An apparatus is provided for combining oxygen and fuel to produce a mixture to be burned in a burner. The oxygen-fuel mixture is ignited in a fuel-ignition zone in a flame chamber to produce a flame.

Abstract: Flame stability of a burner that is operated with a mixture of oxygen and flue gas as the oxidant, is enhanced by including a second burner that combusts fuel with oxidant having a high O2 content.

Abstract: A center burn technology for a stove or dryer for the burning of solid, loose or compressed fuels, or mixtures of fuels. The stove uses a center burn draft and combustion through the combustion material. The preferred embodiment of this stove consists of at least two bins, an outer exhaust bin and inner combustion bin. A vertically placed air core combustion tube is resting within a stabilizing support collar at the top and at the bottom the tube rests inside of a tapered apparatus. The smaller opening at the bottom of the tapered apparatus provides return gas venting and easy ash drop system to ash bin or pan below. Exhaust drafts through vents between said bins at the upper portion of the inner combustion bin. The stove provides a long efficient burn with a steady combustion temperature. The stove does not require the use of electricity.

Abstract: A method for heating a blast furnace stove includes combusting a fuel with a lower heating value (LHV) of 9 MJ/Nm3 or less in a combustion zone which is arranged in a combustion chamber in the stove, and causing the combustion gases to flow through and thereby heat refractory material in the stove. The fuel is combusted with an oxidant including at least 85% oxygen, and combustion gases are recirculated into the combustion zone for diluting the mixture of fuel and oxidant therein sufficiently for the combustion to be flameless.

Abstract: A method and apparatus for combustion in which a pressurized preheated liquid fuel is atomized and a portion thereof flash vaporized, creating a mixture of fuel vapor and liquid droplets. The mixture is mixed with primary combustion oxidant, producing a fuel/primary oxidant mixture which is then injected into a primary combustion chamber in which the fuel/primary oxidant mixture is partially combusted, producing a secondary gaseous fuel containing hydrogen and carbon oxides. The secondary gaseous fuel is mixed with a secondary combustion oxidant and injected into the second combustion chamber wherein complete combustion of the secondary gaseous fuel is carried out. The resulting second stage flue gas containing very low amounts of NOx is then vented from the second combustion chamber.

Abstract: In an oxygen mixer for an oxygen combustion boiler, circulating exhaust gas heated in a rotary preheater is mixed with oxygen. Resultant mixed gas is guided to a boiler furnace through a combustion gas duct having bends. At the bend closest to the rotary preheater in the combustion gas duct, an oxygen injection nozzle is arranged to have a plurality of injection ports for injection of oxygen into circulating exhaust gas.

Abstract: A burner has a fuel/oxidant nozzles and a pair of dynamical lances spaced on either side thereof that inject a jet of fuel and primary oxidant along a fuel injection axis, and jets of secondary oxidant, respectively. Jets of actuating fluid impinge against the jets of secondary oxidant to fluidically angle the jets of secondary oxidant away from the fuel injection axis. The action of the angling away together with staging of the oxidant between primary and secondary oxidant injections allows achievement of distributed combustion conditions.

Abstract: Disclosed herein is a method of controlling the operation of an oxy-fired boiler; the method comprising combusting a fuel in a boiler; producing a heat absorption pattern in the boiler; discharging flue gases from the boiler; recycling a portion of the flue gases to the boiler; combining a first oxidant stream with the recycled flue gases to form a combined stream; splitting the combined stream into several fractions; and introducing each fraction of the combined stream to the boiler at different points of entry to the boiler.

Abstract: For a steam generator comprising a combustion chamber fired with a fossil fuel and/or with particulate fuel containing carbon and at least one burner level comprising several burners (1) and/or at least one level comprising nozzles in the form of upper air nozzles and/or side wall nozzles, each having connected feed means (9, 10, 11, 12) and/or feed lines (2, 4, 5, 9a-9d, 10a-10d, 11a-11d, 12a-12d) through which/by means of which gas flows conveying combustion and/or oxidation oxygen can be fed to burners (1) and/or the nozzles (13) and/or the combustion chamber, a solution should be created by means of which undesired oxygen contents in the flue gas can be avoided during oxyfuel operation of the steam generator in the partial-load range.

Abstract: An air pollution control system includes an emission treatment system configured to receive flue gas, to reduce at least one pollutant therefrom, and to output emission treated flue gas. A first air heater in fluid communication with the emission treatment system includes a heat exchanger for heating forced air introduced thereto above a base temperature and thereby cooling emission treated flue gas from the emission treatment system to a stack discharge temperature. A second air heater in fluid communication with the first air heater to receive heated forced air therefrom includes a heat exchanger for heating forced air introduced thereto to a preheat temperature for combustion in a boiler and thereby cooling flue gas introduced from a boiler to the second air heater to an emission treatment temperature. The second air heater is in fluid communication with the emission treatment system to introduce cooled flue gas thereto.

Abstract: A biomass thermochemical gasification apparatus is provided that can manufacture high-quality fuel gas out of solid biomass in an industrial manner. This fuel gas can be used as fuel for a gas engine and a gas turbine for example and also can be used as synthesis gas for methanol synthesis. A high-temperature combustion gas generation apparatus (101) for biomass operates entirely by biomass and the heat source thereof does not depend on fossil fuel. A coarsely-ground powder biomass (205) subjected to gasification and gasification agent (303) are introduced to a primary gasification reaction room (202) and generate gasification reaction by, as reaction heat, radiation heat from a wall face of the primary gasification reaction room (202) heated by combustion gas (109a) generated in the high-temperature combustion gas generation apparatus (101) and are dissolved. Consequently, the biomass (205) is converted to clean and high-quality generated gas.

Abstract: A method of preparing an oxidant stream comprising: burning a combustion mixture comprising (a) one or more fuel composition and (b) oxidant comprising a first oxygen content of about 10 mole % or more and a first carbon dioxide (CO2) gas content of about 68 mole % or more on a dry basis, the burning producing a flue gas comprising CO2 gas, water vapor, and unreacted oxygen; separating from the flue gas a recycle stream; mixing at least a portion of the recycle stream having a first pressure with a sufficient amount of an oxygen stream having a second pressure which is sufficiently higher than the first pressure to entrain at least a portion of the recycle stream in the oxidant stream and to produce the oxidant stream having a second oxygen content of 10 mole % or more and a second CO2 gas content of about 68 mole % or more on a dry basis.

Abstract: A design and method of operation for the floor of solid fuel boilers is described. The combustion region includes a stepped-floor that improves combustion in the lower furnace. In some embodiments, the fuel is moved between the steps of the floor by a gas, rather than by mechanical means, and the fuel is moved from an upper to a lower step as it is burned. In some embodiments, the steps are fixed steps having a layer of a refractory material.

Abstract: A rotary hearth furnace includes an exhaust gas eductor. The exhaust gas eductor includes a compartment-defining portion and an exhaust duct. The compartment-defining portion is provided on part of a ceiling of the rotary hearth furnace in an exhaust gas discharge region, and an exhaust duct is connected to the compartment-defining portion. The lower surface of the compartment-defining portion lies higher than the lower surface of the other portion of the ceiling. The compartment-defining portion defines a compartment where the exhaust gas stays. The exhaust duct can include a cooling medium injection nozzle. The furnace increases fuel efficiency by completely burning combustible components remaining in exhaust gas generated in the rotary hearth furnace so as to use the combustible components efficiently for the heating and reduction reaction in the rotary hearth furnace, without problems in producing reduced iron.

Abstract: An oxycombustion circulating fluidized bed reactor includes a reactor chamber, and a gas distribution arrangement provided in the bottom section of the reactor chamber for introducing gas into the reactor chamber. A windbox chamber having gas introduction nozzles introduces gas from the windbox chamber into the reactor chamber and an has an inlet that opens into the windbox chamber. A first gas feeding system introduces gas into the windbox chamber, and a second gas feeding system introduces gas into the wind box chamber in the vicinity of at least one nozzle inlet.

Abstract: In an apparatus of controlling an exhaust gas in an oxyfuel combustion boiler having the boiler 4 provided with burners 6 and a two-stage combustion port 7, a primary recirculation line 12 through which pulverized coal obtained by a mill 3 is fed to the burners 6 of the boiler 4 by the primary recirculating exhaust gas, a secondary recirculation line 14 through which another portion of the exhaust gas in recirculation is fed to a wind box 5 of the boiler 4, an oxygen producer 23, a direct supply line 25 through which a portion of oxygen produced by the oxygen producer 23 is directly fed to the burner 6 and a secondary oxygen mixing line 24 through which another portion of oxygen produced by the oxygen producer 23 is fed to the secondary recirculation line 14, the apparatus comprises an oxygen supply line 26 through which oxygen is fed to the two-stage combustion port of the boiler 4 and a flow rate regulator 20, 27 in the oxygen supply line for adjusting oxygen density.

Abstract: An air pollution control system includes an emission treatment system configured to receive flue gas, to reduce at least one pollutant therefrom, and to output emission treated flue gas. A first air heater in fluid communication with the emission treatment system includes a heat exchanger for heating forced air introduced thereto above a base temperature and thereby cooling emission treated flue gas from the emission treatment system to a stack discharge temperature. A second air heater in fluid communication with the first air heater to receive heated forced air therefrom includes a heat exchanger for heating forced air introduced thereto to a preheat temperature for combustion in a boiler and thereby cooling flue gas introduced from a boiler to the second air heater to an emission treatment temperature. The second air heater is in fluid communication with the emission treatment system to introduce cooled flue gas thereto.

Abstract: Provided are a method and an apparatus of controlling an oxygen supply in an oxyfuel combustion boiler capable of attaining stable oxyfuel combustion even when properties of coal are changed. A boiler-brought-in oxygen density is obtained when coal with a fuel ratio measured by fuel measuring means 39 is burned stably with oxygen in a boiler 4 so that a relationship between the fuel ratio and/or carbon content of the coal and the boiler-brought-in oxygen density is obtained and inputted in advance into the controller. When the coal is changed to the new kind of coal, a total amount of gases recirculated is regulated such that a boiler-brought-in oxygen density becomes accordance with a fuel ratio and/or a carbon content which is measured in advance for the new kind of coal.

Abstract: An oxyfuel combustion boiler plant comprising: an air separation unit for manufacturing oxygen by separating nitrogen from air, a boiler having a burner for burning the oxygen supplied from the air separation unit and pulverized coal, and a primary system pipe for supplying the pulverized coal to the burner, an exhaust gas recirculation system pipe for supplying combustion exhaust gas discharged from the boiler to the primary system pipe, and a carbon dioxide capture unit for capturing carbon dioxide in the exhaust gas discharged from the boiler, the oxyfuel combustion boiler plant is further comprising: an oxygen supply pipe for supplying the oxygen manufactured by the air separation unit to the primary system pipe in the burner, and a pipe for supplying the combustion exhaust gas discharged from the boiler to the oxygen supply pipe, wherein an injection port of the oxygen supply pipe is disposed on an upstream side of an injection portion of the burner.

Abstract: A system for feeding a primary oxidant to an oxy-fired circulating fluidized bed (CFB) boiler. The system includes a plurality of bubble cap assemblies each comprising a stem and a bubble cap with at least one exit hole, each bubble cap connected via a stem to at least one windbox, the windbox containing at least one manifold. A plurality of pipes are provided, each pipe located within a bubble cap assembly with an open end located either at, above or below the exit holes of the bubble caps and an opposite end connected to the manifold located inside each windbox. Recycle gas is piped into the windbox, to the stem, and exiting from the exit holes located in the bubble cap into the CFB. Oxygen is piped into the manifold, through the pipes and exiting through the exit holes located in the bubble cap.

Abstract: An oxyfuel boiler structured so as to mix oxygen separated from air with a part of exhaust gas branched from exhaust gas discharged from the boiler for generating vapor and supplying to a vapor demand facility by burning coal fuel, and supply the mixed gas to the boiler as an oxidizing gas for burning the coal, wherein an air separation unit for separating air and manufacturing oxygen from air, an oxygen supply system for leading the oxygen manufactured by the air separation unit to the oxyfuel boiler, a recirculation system for leading a part of exhaust gas branched from the exhaust gas discharged from the oxyfuel boiler to the oxyfuel boiler, and a recirculation fan for supplying the exhaust gas to the recirculation system are installed, respectively.