Abstract: This invention discloses a pellet fuel combustion device, which comprises an electric arc ignition pin installed in the combustion chamber to generate high-voltage electric arc. The pellet fuels transported by the feeding mouth start burning once they touch the electric arc. High-voltage electric arc is generated by electric arc ignition pin the moment the pellet fuel combustion device starts up, which accelerates igniting speed greatly and reduces power consumption. Furthermore, the fuel pellets can achieve full burning by scattering and touching electric arc without bringing on smeek. Hence, this invention has great advantages over conventional ignitions which produce heat and fire by resistance wire.

Abstract: An inside of an incinerator body into which sludge is fed is divided into a lower portion, a portion above the lower portion, and a top portion in a height direction. The lower portion serves as a pyrolysis zone for supplying fluidizing air having an air ratio of 1.1 or less together with fuel to thermally decompose the sludge while fluidizing the sludge. The portion above the lower portion serves as an over bed combustion zone for supplying only combustion air having an air ratio of 0.1 to 0.3 to form a local high temperature place to decompose N2O. The top portion serves as a perfect combustion zone for perfectly combusting unburned contents. The quantity of N2O generated during sludge incineration can be drastically reduced while maintaining the use quantity of auxiliary fuel at the same level as that of a conventional incineration method.

Abstract: A method to regulate overfire air passing through an overfire air duct and entering a flue gas stream in a combustion system including: directing overfire air into an inlet of the overfire air duct, passing the overfire air through the duct and discharging the overfire air into the flue gas stream in the combustion system; adjusting a flow rate of overfire air entering the inlet using a damper adjacent the inlet, and moving the damper parallel along an axis of the overfire air duct to increase and decrease the overfire air entering the inlet, wherein the damper has an open position at which the damper is extended out of the inlet and a closed position in which the damper is substantially in the inlet and blocking air entering the inlet.

Abstract: Thermal oxidiser (1) for the oxidation of a feed liquid (W) comprising an elongated retort (3) provided with a combustion gas input lance (5), a feed liquid input lance (7), one or more flow straighteners (11) and an exhaust gas outlet (13) wherein said retort (3) comprises an elongated wall (15) with a first end plate (17) fastened to a first end (19) thereof and a second end plate (21) fastened to the second, opposite end (23) thereof, combustion gas input lance (5) projects substantially horizontally through first end plate (17) into said retort (3) and feed liquid input lance (7) projects downwards though the retort wall into said retort (3).

Abstract: The oxyfuel boiler system comprises: an oxygen generator; a coal mill; a burner to burn pulverized coal; an after-gas port to which oxygen generated at the oxygen generator is supplied; a boiler provided with the burner and the after-gas port on its wall; a flue introducing combustion exhaust gas from the boiler to the outside; a recirculation gas supply pipe having an exhaust gas tapping port in the midway of the flue and supplying recirculation exhaust gas to the coal mill, the burner, and the after gas port; and an oxygen supply pipe supplying oxygen from the oxygen generator to the burner and the after-gas port, wherein the exhaust gas tapping port is disposed downstream of a dry dust-removing apparatus arranged in the flue, and there is provided an oxygen controlling apparatus for making a concentration of oxygen to be supplied to the after-gas port lower than that of oxygen to be supplied to the burner.

Abstract: An arrangement is disclosed for supplying an air jet form to the furnace of a recovery boiler, where the furnace has a front wall, a rear wall and side walls. Black liquor spraying devices are disposed on the furnace walls on one or several levels of the furnace. A plurality of air ports are located at several horizontal elevations for introducing air into the furnace from an air supply. In the arrangement for the secondary air flows, at least two horizontal air levels at different elevations are arranged above the lower primary levels and below the black liquor sprayer. Secondary air is supplied from two opposite walls. The secondary air ports on each of said first and second horizontal elevations comprise air ports for each horizontal elevation that project a pattern of large air jets into the furnace from said opposite walls and said secondary air ports further comprise a plurality of secondary air ports on at least one of the elevations that project smaller air jets into the furnace.

Abstract: A combustion system for extracting thermal energy from biomass or other formable fuels that does not require densification or other processing of the biomass prior to combustion. This system continuously feeds the biomass fuel from an auger or other conveyance system while simultaneously causing the biomass fuel to be formed with a hollow core. The biomass fuel is ignited from within the hollow core and burns primarily radially outward due to negative pressure surrounding combustion chamber thus facilitating and containing the combustion process. This system also utilizes pre-heating the fuel, primary and secondary air pre-heating, insulated combustion chambers, and carefully control combustion air to ensure substantial combustion is achieved even with fuels having high moisture content. In the preferred embodiment, a heat exchanger is utilized to capture thermal energy of combustion products for use as an energy source for additional processes.

Abstract: This invention improves gas mixing and combustion, gaseous fluid flow and control of the char bed in recovery boilers burning black liquor or soda liquor, requires fewer primary air ports than conventional methods and can reduce capital and operating costs. Some primary air is introduced as powerful principal jets, from two opposing so-called active furnace walls. All or most of the remainder of the primary air is introduced as smaller jets, called scavenging jets, which prevent char from accumulating in the furnace corners and, in some cases, between the principal jets and are in the same plane as the principal jets. The momentum flux of each of the principal jets is approximately double or more than double that of each scavenging jet. Some of the primary air may be introduced as central jets, from the remaining two furnace walls and located in the same plane as the other ports, or on a second, somewhat higher plane. The momentum flux of the central jets is less than that of the principal jets.

Abstract: A boiler assembly including primary and secondary combustion chambers includes primary and secondary air controls for controlling combustion air to the chambers respectively. The air controls are operable between open positions to allow combustion in the chambers and a closed position in which the combustion air passages are fully sealed to fully interrupt combustion responsive to heating demands. The air controls are supported externally on the main housing of the boiler assembly so as to be modular and readily releasable from the main housing and the respective combustion air passages. The primary combustion chamber communicates with the secondary combustion chamber at a location partway in between introduction of the secondary combustion air and the exhaust passage.

Abstract: The method and furnace according to the invention enable a continuous processing of anode slime and are particularly suited to be connected to a process where anode slime is treated by hydrometallurgic methods after roasting. In the method according to the invention, the slime containing valuable metals and selenium is dried, roasted, sulfatized and cooled. The method includes steps to be carried out in succession, in continuous operation, so that the slime forms a slime layer on the conveyor and is conveyed to be treated in successive drying, roasting, sulfatizing and sulfuric acid removal and cooling units.

Abstract: A combustion chamber (10) for burning solid fuels having a high volatiles content has a hollow body (11) with a cylindrical wall section (12) and a top section (13) located at end (14) of the cylindrical wall section (12). The hollow body (11) has a primary air inlet (20), a fuel inlet (23) and four volatiles outlets (25) (one shown), mounted therein. Each volatiles outlet (25) has a plurality of apertures (26) of differing sizes arranged in a plate (27). In use, the burning volatiles exit the apertures (26) in a turbulent flow resulting in efficient combustion of the volatiles. Additionally, a heat transferring surface (33) on a water jacket (32) is shaped around the combustion chamber (10) so as to define a channel (34) there between. This arrangement results in an efficient transfer of heat from the turbulent flow of volatiles, which is forced to circulate around the channel (34).

Abstract: The present invention provides a highly reliable pulverized coal boiler that ensures suppression of a rise in flame temperature caused during the combustion of an unburnt gas in a furnace when combustion air is supplied from after-air ports so as to reduce the concentration of thermal NOx generated during the combustion.

Abstract: A combustion installation comprising a combustion device for combustion of a fuel and an oxygen-containing gas to a combustion gas and a method for such combustion is described. A nozzle means is arranged for injection of the fuel into the combustion device and a membrane device for supplying oxygen to the combustion gases for production of the oxygen-containing gas, wherein the combustion device comprises at least a first inlet for the oxygen-containing gas and an outlet for the combustion gases. The combustion installation comprises at least a first ejector including the nozzle means and the first inlet, wherein the nozzle means and the first inlet are arranged to drive the flow of oxygen containing gas and fuel through the combustion device.

Abstract: The present invention relates to a system for carrying out oxygen-enhanced combustion in an industrial process wherein the industrial process, an oxygen supply system or a source of oxygen, a heat recovery network, and an alternative Rankine cycle system based on a working fluid other than steam are integrated to achieve improved throughput and efficiency, and a method for oxygen-enhanced combustion in an industrial process using said system. Examples of industrial processes include cement production, steel reheat applications, glass production, aluminum and copper melting, as well as any industrial process that uses process heater, furnaces where combustion is carried out using an oxidant stream with oxygen content higher’ than that in ambient air and up to 100%.

Abstract: A granular biomass burning furnace for use with any appropriate granular biomass, such as grains, cherry pits, etc. The furnace includes a three stage heat exchanger, a fuel injector, a fuel stirrer, an ash ejector, a wash down system, a three stage air inducer, a fuel igniter, and supporting components. The unit includes a computer controller which controls all aspects of the operation of the unit based on information from sensors located throughout the unit. The unit includes a smart logic thermal controller to adjust the output heat of the unit via a variable speed air inducer. The three stage heat exchanger system includes a spiral water jacket surrounding the burn pot, a plurality of heat exchanger baffles in the unit, and a fine finned heat exchanger at the top of the unit. The air inducer provides air to the burn pot from three directions to promote complete combustion.

Abstract: The invention provides a combustion process using comminuted fuel solids from a steam-driven shear field, with controlled water content and optionally coated with a combustion catalyst. The method allows fuel solids to burn for energy production at low temperatures. The lower temperatures avoid emissions of nitrogen oxides, and the process also yields a clean, friable ash that has economic value.

Abstract: Processes and compositions are provided for decreasing emissions of mercury upon combustion of fuels such as coal. Various sorbent compositions are provided that contain components that reduce the level of mercury and/or sulfur emitted into the atmosphere upon burning of coal. In various embodiments, the sorbent compositions are added directly to the fuel before combustion; are added partially to the fuel before combustion and partially into the flue gas post combustion zone; or are added completely into the flue gas post combustion zone. In preferred embodiments, the sorbent compositions comprise a source of halogen and preferably a source of calcium. Among the halogens, iodine and bromine are preferred. In various embodiments, inorganic bromides make up a part of the sorbent compositions.

Abstract: In a boiler, a space is reserved to expand the boiler by increasing the front and rear walls. To expand the boiler, wall additions are added to increase the width of the front and rear walls. After the expansion, the distance between the front and rear walls is substantially the same distance between the front and rear walls before the expansion.

Abstract: An apparatus for extracting energy from fiber introduced as a fuel into a vertically elongated combustion chamber having a suspension burner capable of projecting a flame down the axis of the combustion chamber with a heat collection surface located radially from the flame and below the burner, and an exhaust opening located below the flame and below at least a portion of the heat collection surface, in which the combusted fiber yields a mixture containing hot flue gas and molten ash above the exhaust opening and heat transfers therefrom to the heat collection surface prior to any substantial contact of ash to a surface of the combustion chamber, to yield a mixture containing warm flue gas and non-molten ash, that is thereafter cooled to yield a mixture containing cool flue gas and non-molten ash.

Abstract: A boiler incorporates an overfire air injection system for reducing NOx emissions. The boiler comprises a combustion device including a plurality of main burners supplied with fossil fuel and air for burning in a combustion zone, where the burners produce flue gases that flow from the combustion zone into a burnout zone. The boiler further comprises at least one overfire air injector for supplying overfire air to the combustion device and at least one booster overfire air injector for supplying high-pressure air to the combustion device.

Abstract: The invention relates to a system for controlling the flow field in a soda recovery boiler, said soda recovery boiler comprising at least a furnace (1), primary air ports (4) in the lower part of the furnace, so-called secondary combustion air ports (5) disposed above these, black liquor spray nozzles (6) placed similiarly above these and combustion air ports (5b) disposed above the black liquor spray nozzles (6). According to the invention, the soda recovery boiler is provided with substantially thin jets (7, 7a, 7b) supplying energy into the flow field and having a jet pressure in the nozzle equal to at least twice the jet pressure in the combustion air ports (5, 5b).

Abstract: An Overfire Air (OFA) port design and method for use in a furnace system is disclosed. The OFA port design effectively reduces the amount of harmful pollutants emitted into the atmosphere upon discharge from an associated furnace.

Abstract: A method and a system for feeding combustion air of a soda recovery boiler to a furnace. The air is fed to the boiler furnace as primary air jets and auxiliary airjets, which are substantially shorter than the primary air jets. At least one primary airjet is placed between two opposite auxiliary air jets.

Abstract: The method of carbonization of organic waste according to the present invention comprises the steps of supplying organic waste to a dryer, reducing an amount of water in the organic waste by heating with high-temperature gas, supplying the organic waste to a carbonization furnace for carbonizing the organic waste in a high-temperature ambience, removing carbide from the carbonization furnace, incinerating gas, which is generated in the carbonization furnace, in a re-incinerating furnace, and supplying combustion gas of the re-incinerating furnace to the dryer as the high-temperature gas.

Abstract: A method and/or apparatus for efficiently operating a combustion device including at least one control zone, with each control zone including at least one burner assembly, is disclosed and includes a) individually supplying fuel to each of the burner assemblies in each of the control zones, b) individually measuring a separate combustion characteristic of the collective combusted gas from each of the burner assemblies in each of the control zones, and c) individually adjusting the flow of air to each of the burner assemblies in response to the value of the combustion characteristic corresponding to each of the control zones to keep the value of each separate combustion characteristic within a predetermined range. In a preferred embodiment, primary air and secondary air are separately supplied and controlled to each of the burner assemblies in each of the control zones in response to the value of the combustion characteristic corresponding to each of the control zones.

Abstract: A furnace consists of at least one wall-mounted burner tilted downward for feeding air-fuel mixture and of a prism-shaped ash hopper. Slopes of the walls of lower combustion chamber region define the slotted mouth of ash hopper. The bottom airflow device is located below the ash hopper mouth the wall opposite to the airflow nozzle of the bottom airflow device has a concave form. In accordance with said invention the bottom airflow device spans along the entire width of the ash hopper mouth. The concave wall in its upper region meets the ash hopper mouth and an imaginary plane being a continuation of said concave wall crosses the opposite slopes of the wall of ash hopper in its middle region. The axis of bottom airflow nozzle passes along the lower region of said concave wall and is directed to form a 0-to-45 degree angle between said axis and lower region of said concave wall. The concave wall may be tilted relative to horizon at the angle of 20-45 degrees.

Abstract: Apparatus and method for generating fuel gas and optionally, activated carbon gasification from biomass fuel.

Abstract: A method and portable apparatus is described for the conversion of cellulose and other blomass waste materials through a pyrolysis and partial combustion sequence in a downdraft gasifier to produce a gas which can be immediately utilized to fuel an internal combustion engine in a generator set (genset). More specifically, the heat from the combustion of part of the cellulosic or other waste input is used to pyrolyze the remainder of the input to produce a mixture of permanent fuel gases. Particulates are removed (water scrubbers, filters) from the gas mixture which can then be used directly as a major part of the fuel to operate the internal combustion engine in the genset. All movement into, through, and out of the gasifier and purification train is controlled by the vacuum associated with the intake of the internal combustion engine, thereby ensuring a steady production of electricity.

Abstract: An Overfire Air (OFA) port design and method for use in a furnace system is disclosed. The OFA port design effectively reduces the amount of harmful pollutants emitted into the atmosphere upon discharge from an associated furnace.

Abstract: A furnace blower housing has a two-piece exhaust transition, one piece of which is an integral extension of the blower housing, that transitions a rectangular cross section outlet of the blower housing to a circular cross section outlet of the exhaust transition that is adapted to be attached to a circular exhaust pipe.

Abstract: A process and furnace for melting glass is set forth wherein the majority of the combustion energy over the melting zone of the furnace is provided by oxy-fuel combustion while a majority of the combustion energy over the fining zone of the furnace is provided by air-fuel combustion. In many cases, it will be preferable to provide greater than 70% and up to and including 100% of the combustion energy over the melting zone by oxy-fuel combustion and greater than 70% and up to and including 100% of the combustion energy over the fining zone by air-fuel combustion. By proper tailoring of the combustion space atmosphere through oxy-fuel and air-fuel firing, the present invention can result in an improvement in glass productivity and quality. The present invention can be applied in the construction of a new furnace or can be applied to existing air-fuel furnaces.

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.

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.

Abstract: The furnace is intended for burning solid fuel (mainly fire-wood) in continuous mode of operation, with significant amount of heat released in the form of hot combustion products usable in wood-drying installations, for house heating, destroying of refuse, etc. The invention allows simplifying the design of the furnace, features high efficiency of fuel burning and high power density, and improves reliability and serviceability. The furnace includes the shaft loading hopper (1), the combustion chamber (2) located under the loading hopper (1), and the expansion chamber (3) located behind the combustion chamber (2) and provided with the forced ventilation (5). The atmospheric air, heated to the temperature of combustion products in the expansion chamber (3), is supplied to the combustion chamber (2).

Abstract: A blast tuyere for shaft furnaces, includes a conical hollow main body having inner and outer casings defining a hollow space and interconnected by a tuyere nose. The outer casing is formed by a single-piece base body terminating smoothly in the tuyere nose, and the inner casing is formed by a conical weld-in part. The hollow space is divided in antechamber, adjacent the tuyere nose, and main chamber, completely separated hydraulically and including separate coolant circuits. The coolant circuit for the antechamber includes two parallel passages for supply and return of coolant. The passages terminate in a ring channel, arranged in the tuyere nose in a direction transversely to the passages, and are located in an area of an upper apex of the main body radially outside the main chamber. The coolant circuit for the main chamber includes a helical cooling passageway whose inner wall is formed by the weld-in part.

Abstract: A waste management incinerator has a combustion chamber with a number of U-shaped air supply pipes protruding toward the chamber center. A number of air supply branch pipes are installed on the air supply pipes for supplying air to the combustion chamber to form a vortex-like current circulating in the combustion chamber so as to minimize imperfect combustion. Each air supply pipe is double-structured, having a water pipe connected to an air chamber with the air supply branch pipes located inside penetrating through the water pipe.

Abstract: A method and apparatus for reducing NOx emissions in a furnace having a main combustion zone with a waterwall and apparatus for supplying main combustion air and fuel to the main combustion zone, also reduces unburned carbon and waterwall corrosion in the furnace. The method involves providing at least one lower overfire air injector at a first level over the main combustion zone of the furnace for supplying overfire air to create a lower overfire air zone in the furnace over the main combustion zone and at least one upper overfire air injector at a second level over the lower overfire zone for supplying overfire air to create an upper overfire air zone in the furnace over the lower overfire zone. The overfire air in the lower and upper overfire air zones are supplied at a rate for reducing the stoichiometry in the main combustion zone which reduces unburned carbon and a corrosive reducing atmosphere in the furnace.

Abstract: In this process the material is passed through a precalcination device equipped with at least one fuel injector at the outlet of which a fuel injection zone is formed, then the at least partially calcined material is passed into the rotary kiln which at its downstream end, is equipped with a primary combustion unit. At least one oxygen rich fluid with an oxygen concentration by volume higher than that of the products of combustion from the rotary kiln is injected near to the injection zone so that the oxygen rich fluid can supply from 1% to 40%, and preferably form 1 to 10% of the stoichiometric amount of oxygen needed for the combustion of the fuel injected by the injector.

Abstract: This invention improves fluid flow, gas mixing and combustion in the furnaces of recovery boilers which burn liquor from various pulping processes, namely, the kraft process, the soda process, the sodium-based sulphite process, the closed-cycle CTMP (chemical, thermal, mechanical pulp) process, the magnesium-based sulphite process and the ammonium-based sulphite process, which are employed in the manufacture of pulp and paper, and in the furnaces of boilers burning biomass, wood waste or other solid fuel. The invention improves the operation of new or retrofitted boilers in several ways and can reduce both the capital and operating costs. One embodiment comprises introducing a portion of the combustion air, and/or recycled flue gas, at any elevation in the furnace, from two opposing walls only, as jets arranged in a partially-interlaced manner, with the jets oriented in a more or less common plane which is inclined.

Abstract: A method and an apparatus for optimizing the combustion air system in a power boiler or chemical recovery boiler by improving fluid flow and gas mixing are disclosed, whereby one can increase boiler capacity and combustion uniformity and reduce particulate and gaseous emissions. The method involves interlacing of the secondary and, where applicable, the tertiary air supply through opposing air ports on all four walls of the boiler, and is implemented by alternately opening wide or partially closing a port damper on one side, while partially closing or opening wide a port damper on the opposite side, such that a 70-100% open damper on one side opposes a partially closed (10-40% open) damper on the other and vice versa in an alternating fashion, along opposing walls.

Abstract: A burner isolation valve or gate for use in the coal-delivery pipes of coal-fired power plants. Safety regulations often require that two valves be placed in the coal delivery line between a combustion chamber and an exhauster or pulverizer type deliver source to isolate the section of pipe in between for maintenance and other access. The invention includes a novel valve plate and actuation assembly, a novel housing adapted to sealingly enclose the valve plate, and a novel sealing mechanism for the valve plate and housing adapted to keep coal fines and dust out of the outboard portion of the housing in which the valve plate rests in the valve-open position.

Abstract: The present document describes a wind box used in the air supply of a chemical recovery furnace, the wind box comprising a frame (1) having at least one air inlet opening (2) and at least one air supply opening (3) through which air is led from an air channel via the wind box to the recovery furnace. The wind box further comprises at least one combined actuator (25) for regulating the air flow through the wind box and for cleaning each air supply opening (3) as well as means (19, 21) for moving each actuator (25). The invention is based on using a cleaning head (15) smaller than the air supply opening (3) when cleaning the air supply opening (3), whereby its path instead of a longitudinal motion is determined to be curved such that one to and from motion of the cleaning head will rub of all deposit from both the upper and the lower edge of the air supply opening (3) and also from the area between these.

Abstract: A furnace is provided for burning soila organic fuels including highly volatile organic fuels. A combustion chamber with an ash hopper has a slot mouth opening defined by slopes of the walls of the combustion chamber. A burner is disposed beneath the ash hopper mouth opening and extends across its entire width. A bottom blast inlet device generates a turbulent zone in the lower region of the combustion chamber. A duct is further provided for injecting a sulfur-absorbent material into the furnace chamber. The duct is disposed between the burner and the ash chamber and defines a longitudinal axis which traverses the turbulent zone. Preferably, the burner is tilted downwardly and is disposed on a wall in common with the sulfur-absorbent induction duct. The proportion of the sulfur-absorbent materials in the fuel mixture is in the range of 10% to 100% by mass.

Abstract: The windbox burner has a register casing (2) with ports (3) for inflow of combustion air, secondary air pipe (35) enclosed by the register casing and having inlet ports (36) for secondary air, a ring damper (20) coaxial with the register casing and axially displaceable and having at each end an annular sealing means (21; 26) which in the closed position of the ring damper sealingly abuts a corresponding sealing arrangement (23; 22) at each axial end of the ports (3), thus preventing the combustion air from flowing through the ports (3) to the burner tip. Each of the sealing arrangements (21, 23; 22, 26) is made of a stainless and heat-resistant material, and each pair of the sealing arrangements is constituted by a plane leaf spring (23; 26) the plane of which is substantially perpendicular to the longitudinal axis of the ring damper (20), and a ring (21, 22) with a convex surface on which the leaf spring abuts tangentially in the closed position of the ring damper.

Abstract: An air compartment of a corner windbox of a tangential firing system of a fossil fuel-fired furnace for injecting secondary air into the furnace. The air compartment includes a channel portion with an entrance end communicating with an air delivery duct and an exit end communicating via an exit assembly with the furnace opening. The exit assembly includes at least one vane for guiding an air stream and a mounting frame for supporting the vane relative to the channel portion for guiding thereby of an air stream passing from the channel portion through the furnace opening into the furnace. The vane includes a surface portion which intersects the horizontal plane at an acute angle and a pair of opposed transverse edges. The vane and the mounting frame are disposed within the channel portion such that the leading edge of the vane is upstream of the furnace opening.

Abstract: An air nozzle for introducing secondary air into a furnace and including a housing provided with an inlet at one end thereof for receiving air and an outlet at the other end thereof for discharging the air. A damper is disposed in the housing in the path of the air for splitting the flow of the air into two flow streams which extend to different areas of the furnace and is adapted for pivotal movement in the housing to vary the amount of air flow in each of the streams and the discharge angle of one of the streams.

Abstract: A register for use in conjunction with kraft recovery boilers or bark-fired boilers utilizes a pair of shaped damper foils to reduce turbulence and induce laminar flow of air from an associated windbox through a port in the boiler. The foils are mounted for constant minimal separation from an exit nozzle to reduce transitional discontinuities which induce turbulence. A curved plenum is also provided to reduce internal turbulence within the plenum.

Abstract: A boiler recovers a soda component from pulp spent liquor and is able to prevent carry-over of unburnt char and deformation of a char bed configuration and to attain a stable combustion with low NOx generation. By regulating the combustion air supply, and feeding inert gas along a furnace side wall around the char bed, there are formed a combustion zone of reduction atmospheric field where air ratio in the surroundings of the char bed is 0.8 or less, a combustion zone of reduction atmospheric field where air ratio is 1.0 or less and unburnt components exist (including the case of a reduction atmospheric field where air ratio is 1.0 or less and unburnt components exist with the two combustion zones being combined together) and a combustion zone where combustion is completed.

Abstract: A method and apparatus retrofitted to a multiple-intertube pulverized-coal burner to reduce NO.sub.x emissions of roof fired boilers. An internal two stage process controls the amount of secondary air which flows to the burner. The first stage includes a secondary air damper and air flow station to regulate the amount of air which flows into a windbox of the burner. The second stage includes an outlet formed in the hot primary air duct, an air plenum which communicates therewith, and a plurality of interjectory air ports which correspond with the burners in number and position along a front wall of the boiler and which communicate with the air plenum. The interjectory air ports inject interjectory air into a combustion chamber of the boiler at a substantially 90 degree angle to the direction of a plurality of burner tips of each burner and supplies the balance of the required theoretical combustion air needed to complete combustion of the fuel.

Abstract: An air nozzle for introducing secondary air into a furnace and including a housing provided with an inlet at one end thereof for receiving air and an outlet at the other end thereof for discharging the air. A damper is disposed in the housing in the path of the air for splitting the flow of the air into two flow streams which extend to different areas of the furnace and is adapted for pivotal movement in the housing to vary the amount of air flow in each of the streams and the discharge angle of one of the streams.