Abstract: A process for combustion of a combustible material in which a primary combustible material is introduced into a combustion chamber having an upstream region and a downstream region, and ignited, forming a primary combustion zone. A secondary combustible material is partially combusted in a partial combustor, forming partial combustion products which are then injected into the combustion chamber downstream of the primary combustion zone, forming an oxygen deficient zone downstream of the primary combustion zone.

Abstract: A system and method for protecting a nozzle that injects a high velocity main gas into a furnace or combustion zone. The nozzle is located in a passage recessed from the exit port opening of the passage which communicates with the combustion zone. Purge gas is passed into the passage upstream of the nozzle. The volume of the purge gas exceeds 50% of the total volume of the main gas and purge gas and the purge gas has a velocity of at least 100 ft/sec thereby preventing furnace gases from entering the passage and attacking the nozzle.

Abstract: The present invention relates to a low nitrogen oxygen regenerative burner, a regenerative burner system and a regenerative burning method. The low nitrogen oxide regenerative burner is comprised of one or more pairs of regenerators having a regenerating section inside and air supply and exhaust ports which open directly opened into a furnace; and one or more fuel injection nozzles for each of the air supply and exhaust ports, which also open directly into the furnace at locations apart from the corresponding air supply and exhaust port. The regenerative burner system consists of a furnace body, the low nitrogen oxide regenerative burner and a control means. The regenerative burning method is the process whereby air is preheated in the regenerator, injected from the air supply and exhaust ports of the regenerators into the furnace, fuel from the fuel injection nozzles located apart from the air supply and exhaust ports, is injected.

Abstract: Periodic, on-demand supply of heated and pressurized gas for use as a power source is provided by a device having a storage compartment storing pressurized, liquified, combustible gas, a pressure regulator attached thereto for feeding the liquified gas to a housing providing a combustion chamber with an ignition element for combustion of the liquified combustible gas. A pressure relief valve releasably seals the combustion chamber from an outlet orifice and operates at a predetermined gas pressure to permit output of combustion gas from the combustion chamber through the output orifice to provide a gas power source for operating a gas powered tool. A check valve prevents combustion of the liquified gas upstream of the combustion chamber.

Abstract: In a method of operating a plant with staged combustion, the first combustion stage (1a) is operated with a fuel/air mixture (3) whose air coefficient is larger than the overall air coefficient of the combustion system. The hot combustion gases (5) from the first combustion stage (1a) are mixed with an additional fuel/air mixture (4) whose air coefficient is smaller than the overall air coefficient of the combustion system, before the further combustion in the second stage (2a) takes place. Since hot-gas backmixing is no longer required in the second stage (2a) for the flame stabilization, this combined mixture burns without the formation of further NOx emissions.

Abstract: A dual oxidant burner having an inner conduit with a passage communicating with a source of fuel, an outer conduit over the inner conduit and an intermediate conduit between the inner and outer conduits. The three conduits form an inner passage between the inner and intermediate conduits communicating with a source of oxygen, and an outer passage between the intermediate and outer conduits communicating with a source of air. The fuel and the two oxidants are mixed in a furnace or other combustion zone beyond the outlet of the nozzle and the two passages and their flow amounts are individually adjusted to establish the burner flame.

Abstract: A gas burner assembly for connection to a source of gas comprises a burner body having a sidewall and a main gas conduit. The main gas conduit has a burner throat and the sidewall has an inner surface, an outer surface and a top surface. A plurality of primary burner ports are disposed within the sidewall dividing the sidewall into a plurality of sidewall islands. A burner cap is removeably disposed on the sidewall. A plurality of paired opposing ridges are disposed on the top surface of the sidewall wherein a single pair of opposing ridges are disposed on a respective sidewall island so as to define a plurality of carryover slots between the opposing ridges, the top surface and the burner cap. Each carryover slot has an inlet and an outlet.

Abstract: The present invention concerns a low nitrogen oxides generating combustion apparatus and a low nitrogen oxides generating combustion method. The apparatus and method of the present invention, the effect of self-induced exhaust gas recirculation can be obtained to the maximum extent, and the lower flame temperature and the lower oxygen concentration assure remarkably low NOx generation.

Abstract: Method and apparatus for reducing NOx production during air-oxygen-fuel combustion by providing a central core of fuel surrounded by a sheath of oxygen at a combustion end of an air-oxygen-fuel burner. Diametrically opposed air passages are provided on either side of the oxygen sheath to permit entrainment of furnace gases into a flame zone created by primary combustion of fuel and oxygen. Oxygen can be introduced into each air passage to enhance combustion with low NOx emissions.

Abstract: A burner is provided with a burner block having a recess formed in the back thereof for receiving a fuel atomiser and a plurality of oxygen inlets for creating a converging cone of oxygen for intersection with any fuel issuing from the atomiser. Such an arrangement also provides a protective wall for protecting the atomiser from the harsh environment to which the burner is exposed and simplifies the oxygen supply arrangements.

Abstract: The invention provides a method for reconfiguring a burner assembly having an air register, a central burner tip adapted to burn fuel oil, and a plurality of peripheral burner tips adapted to burn a combustion gas. The method is directed to such burner assemblies wherein substantially all of the combustion oxygen is provided by air directed into the air register. The method comprises the steps of replacing the oil-burning central tip with a gas-burning central tip and connecting the central tip to a source of combustion gas. The invention further provides a burner assembly having characteristics of the reconfigured burner assembly prepared from the method of the invention, namely a burner assembly having: an air register, a central burner tip and a plurality of peripheral burner tips, wherein the central burner tip is connected to a combustion gas conduit which has an eductor for drawing combustion oxygen into the central burner tip from a location outside the air register.

Abstract: An object of the present invention is to achieve lower NOx combustion in response to the increasingly intensified NOx regulations for burners. The present invention provides a low nitrogen oxides generating combustion method and apparatus which utilizes effective self-induced exhaust gas recirculation before the initiation of the combustion of diffusion flames, or allows part of the combustion gas to be entrained by auxiliary fuel flow, air flow and fuel flow before the formation of the diffusion flames to further intensify the recirculation flow of the combustion gas by the diffusion flames or, in addition, which can achieve rich and lean combustion in the diffusion flames for decreasing the generation of NOx by a combination of these measures, and which are excellent in flame stability even in a low temperature atmosphere.

Abstract: In a method for operating a combustion chamber (4) equipped with premixing burners, under full load all the burners being operated under identical stoichiometric conditions, the burners are subdivided into at least two burner groups (1, 2 and, in the case of operating conditions below full load, the respective burner groups (1, 2) are operated with different air coefficients (.lambda.1, .lambda.2), that is to say at different flame temperatures (Tgr1, Tgr2). The operating range of the combustion chamber is widened considerably thereby.

Abstract: Provided is a process for the production of a loop-shaped flame in a glass furnace. The furnace includes, in a rear part, a glass melting zone heated by injecting through at least one port a fuel gas and an oxidizer gas having more than 50 vol % of oxygen and, in a front part, a glass refining zone. The process involves defining a stoichiometry coefficient Ks of the flame in the melting zone or the refining zone according to the following formula: ##EQU1## The oxidizer gas and the fuel gas injected through at least the first port are adjusted to obtain a stoichiometry coefficient Ks in the glass melting zone equal to at most 0.8. A fuel-oxidizer mixture is injected into the refining zone to obtain a stoichiometry coefficient Ks in the refining zone which is greater than the stoichiometry coefficient Ks in the melting zone and which is between 0.8 and 1.5. An oxidizer gas is injected into the melting zone in the vicinity of a fume discharge zone to obtain a quantity of oxygen in the fumes of between 0.

Abstract: A nozzle which includes a nozzle body, a central tube contained within the nozzle body for a flow of gas at a temperature less than the temperature of the nozzle body, and an annular passage, located between the nozzle body and central tube, for a flow of gas at a velocity less than the flow of gas in the central tube and less than about 100 ft/sec. enabling the nozzle to operate at elevated temperatures and avoid condensation thereon of vapors from the surrounding gas environment.

Abstract: A burner assembly having improved flame length and shape control is presented, which includes in exemplary emodiments at least one fuel fluid inlet and at least one oxidant fluid inlet, means for transporting the fuel fluid from the fuel inlet to a plurality of fuel outlets, the fuel fluid leaving the fuel outlets in fuel streams that are injected into a combustion chamber, means for transporting the oxidant fluid from the oxidant inlets to at least one oxidant outlet, the oxidant fluid leaving the oxidant outlets in oxidant fluid streams that are injected into the combustion chamber, with the fuel and oxidant outlets being physically separated, and geometrically arranged in order to impart to the fuel fluid streams and the oxidant fluid streams angles and velocities that allow combustion of the fuel fluid with the oxidant in a stable, wide, and luminous flame. Alternatively, injectors may be used alone or with the refractory block to inject oxidant and fuel gases.

Abstract: 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.

Abstract: An apparatus and method for burning the combustible components of a gas stream. The apparatus comprising a a stack pipe having one end in communication with a gas supply pipe for receiving a gas stream and an air supply pipe. Gas and air are introduced into a stack pipe having a mixing zone, stabilization means, an igniter and means to prevent downwash of gaseous products resulting from combustion within the stack pipe.

Abstract: A system for producing a coherent jet of gas wherein a flame envelope is established around a gas jet and directed toward the center axis of the gas jet.

Abstract: A device for injecting fuels (4) into compressed gaseous media essentially comprises a cylindrical hollow body (24) with at least one fuel feed passage (2) and means for the introduction of compressed atomization air (5). A swirl chamber (1) is arranged in the interior of the hollow body (24), this swirl chamber being connected via at least one inlet opening (6) to the fuel feed passage (2). The cross-section of the swirl chamber (1) narrows in the direction of flow of the atomization air passed through the interior of the hollow body (24), thereby forming a cone (8). A dividing wall (20), which extends downstream at least as far as the center of the inlet openings (6), is arranged upstream of the swirl chamber (1), between the fuel in the swirl chamber (1) and the atomization air (5). A method for operating the device is furthermore described.

Abstract: A method for reducing the rate of side wall corrosion in a coal-fired utility boiler. A plurality of side wall slots are provided in the side walls of the boiler so that a protective layer of air may be introduced through the slots and propelled upward by the updraft from the burners.

Abstract: Method for combusting pulverized fuels in a tangentially fired boiler and reducing emission of nitrogen oxides comprises steps of feeding a substantially air-deficient mixture of fuel and primary air through a fuel feeding pipe (1) tangentially into a furnace of the boiler in order to form a reducing flame (II) aNd blowing of at least one stream of combustion air into the furnace. The invEntion is based in that the stream of primary air and fuel is caused to recirculate and turbulate at the open end (2) of the fuel feeding pipe (1) by passing it through a flame holder (9) extending into the fuel feeding pipe (1), and the stream of combustion air is directed away from the primary air/fuel stream in order to prevent the combustion air to mix into the reducing flame (II).

Abstract: A method for reducing the sulfur content in combustion gases from burning coal includes the steps of applying opposite electrostic charges to fuel particles and to reaction particles, and mixing the oppositely charged particles prior to combustion to facilitate the formation of sulfur compounds from sulfur in the fuel upon combustion of the fuel, to thereby reduce the sulfur content in the combustion gases. The reaction particles are preferably a carbonate such as CaCO.sub.3 and MgCO.sub.3. The apparatus for implementing the method includes a first pneumatic line for conveying fuel particles, and a first electrostatic charging device for applying an electrostatic charge to the fuel particles conveyed in the line; and a second pneumatic line for conveying carbonate particles, and a second electrostatic charging device for applying an electrostatic charge to the carbonate particles conveyed in the line that is opposite in polarity to the charge applied to the fuel particles.

Abstract: In a method and a device for burning fuels in a combustion air main stream, the combustion air is passed in a channel over at least one deltoid body. The deltoid body consists of at least one essentially triangular vortex generator area and a downstream, trapezoid flame stabilizer area. In the region of the vortex generator area, fuel is introduced into the turbulent combustion air. The vortex generator area is set via a half sweep angle and an angle of attack relative to the main stream in such a way that the spin of the longitudinal vortexes induced in the main stream is smaller than the critical spin for generating a recirculation zone. The flame stabilization area is set via a half sweep angle and an angle of attack relative to the stream in such a way that the spin of the longitudinal vortexes induced in the stream is greater than the critical spin, so that for each deltoid body, a pair of concave recirculation zones is generated, and the ignited combustion air-fuel mixture is stabilized.

Abstract: In an airblast atomizer nozzle (2) for the operation of a burner (1) operated with liquid and gaseous fuels (4, 6) the intermediate wall (18) between the inner (14) and outer (13) air duct is held via inner and outer support elements (21) which have a sliding fit (28) and which can be designed as swirl vanes. The atomizer edges (19) of the airblast nozzle (2) are angled in the direction of the nozzle axis (11). The nozzle is distinguished by small dimensions, a low pressure loss and a negligible tendency to coking.

Abstract: A spark ignited burner that includes a fuel-oxidant pre-mixing chamber upstream of both an annular ignition spark discharge gap and a main fuel outlet. A continuous ignition discharge spark is established and maintained across the annular ignition spark discharge gap and used to ignite a pre-mixed fuel-oxidant mixture, which in turn is used to ignite the main burner flame.

Abstract: A burner for the combustion of fuel and air in an industrial furnace, for use in connection with preheated combustion air, is provided having an equal number of evenly spaced air jets and fuel jets. The air jets and fuel jets are discharged so that they initially diverge away from one another, but eventually, the fuel jets are entrained by the air jets. During the course of their trajectories, before meeting, the air jets and fuel jets entrain resident furnace gases which results in heavy dilution of the fuel and air before combustion. The dilution causes off-stoichiometric combustion conditions and results in a lower flame temperature. This is similar in effect to external flue gas recirculation. As well, the fuel jets undergo pyrolysis in the course of their trajectories before entrainment occurs. This creates a reducing zone in which the NOx in the resident furnace gases being entrained is reduced, in part, back to molecular nitrogen.

Abstract: A burner configuration includes at least one processing jet nozzle and at least one further burner nozzle having mixing characteristics different from the processing jet nozzle. A means is preferably provided to control the proportions of fuel flow to the nozzles. The nozzles of the set are in sufficient proximity that a combined flame of the burner configuration can be determined or controlled by setting or varying the relative flows of fuel to the nozzle of the set.

Abstract: A method for combusting low heating value liquid by forming a toroidal vortex between atomized liquid and medium velocity oxidant, and carrying out combustion within the toroidal vortex to serve as a dependable ignition source for the main combustion reaction.

Abstract: A process and apparatus are provided for suppressing flame and pressure pulsations in a furnace which has a burner for generating a flame and a combustion chamber into which the flame is directed. Usually, pressure pulsations can occur in such furnaces, which are induced and amplified by ring vortices rolling up on the outer or peripheral regions of the flame and or fuel/air stream. In order to prevent these ring vortices, it is proposed to surround the flame with an envelope of gas which has a higher flow velocity in the direction of the flame than the peripheral region of the flame or the fuel gas/air flow of the burner, whereby a boundary layer acceleration results, and the vortex formation can no longer take place. The furnace burner is provided with one or more gas discharge openings closely surrounding the burner outlet in order to create the gas envelope.

Abstract: A flame cannon for producing an explosion, the cannon including a tank, an effect valve, a nozzle and an ignitor, the tank coupled to a carbon dioxide source and a propane source, the tank and sources used to pressurize liquid propane therein. The nozzle forms a substantially linear and non-atomizing channel. When the effect valve between the tank and nozzle is opened, the pressurized liquid propane is forced through the nozzle and forms a liquid propane column thereabove which begins to disburse into the atmosphere wherein it is ignited to form a mushroom-shaped explosion.

Abstract: A liquid fuel burner apparatus which comprises a fuel distributing member of a generally conical configuration mounted within a housing, along with means for feeding a liquid fuel to an upper end of the fuel distributing member to allow the liquid fuel to form a film on the outer surface. A vaporizing aperture is formed in the outer surface and a gas supply conduit supplied with a pressurized gaseous material to atomize the fuel for ignition. The unburned fuel is then collected and recycled back to the burner. The apparatus permits the burning of material which may contain small particles which would otherwise clog the nozzle of a conventional apparatus.

Abstract: A combustion system in which a coal/primary air mixture is discharged from burners located in the corners of the furnace towards an imaginary circle disposed in the center of the furnace. Air is discharged from air nozzles also located in the corners of the furnace in two flow streams--one directed towards the center of the furnace in a combustion-supporting relation to the fuel, and the other along the inner surfaces of the furnace boundary walls to maintain an oxidizing atmosphere and minimize corrosion and slagging.

Abstract: An oxy-fuel burner according to the present invention includes an outer oxidant tube, an intermediate fuel tube and an inner oxidant tube which are coaxially arranged with the fuel tube disposed between the inner and outer oxidant tubes. Characteristics of the flame produced by the burner may be controlled by varying the relative flow rates of the inner and outer oxidant flows. An increase in the percentage of the total oxidant which is provided to the inner oxidant tube causes the length and luminosity of the flame to decrease and the flame momentum to increase. According to the present invention, the characteristics of a burner flame can be tailored to a particular application without requiring mechanical modification of the burner.

Abstract: A method and apparatus for injecting fuel and oxidant into a combustion burner. At a fuel exit plane of a fuel discharge nozzle, fuel is discharged in a generally planar fuel layer which has an upper boundary and a lower boundary. At an oxidant exit plane, oxidant is preferably discharged in both a top layer along the upper boundary of the fuel layer and a bottom layer along the lower boundary of the fuel layer. In a downstream flow direction, the fuel and oxidant preferably converge in a generally vertical plane and diverge in a generally horizontal plane. The discharged fuel and oxidant form a fishtail or fan-shaped flame configuration. The fuel exit plane can be moved upstream or downstream with respect to the oxidant exit plane to vary the flame characteristics and the flame shape. A refractory manifold can be used to further enhance the fishtail or fan-shaped flame configuration.

Abstract: A method and apparatus for reducing NO.sub.x emissions in a gas burner in which the burner includes a burner supply for supplying fuel gas and primary air to the furnace and projecting the fuel gas into the furnace, a secondary air supply for supplying secondary air to the burner, and a recirculating device for mixing the secondary air with the spent gases inside the furnace, which is then recirculated and combusted to reduce NO.sub.x gases. The method of the invention includes the steps of supplying fuel gas and primary air to the furnace, projecting the fuel gas into the furnace, combusting the fuel gas and primary gas to produce spent gases, supplying secondary air to the furnace, mixing the secondary air with the spent gases inside the furnace to produce diluted air, and recirculating and combusting the diluted air with the fuel gas and primary air to reduce NO.sub.x emissions.

Abstract: A combination burner which uses primary and secondary fuel injection and improves liquid propane combustion. The burner supplies primary air, while secondary air is swirled to shape and mix the flame when the burner is firing "on oil". When the burner is firing "on gas", primary air enters the burner through an annulus at the atomizing air pipe or conduit so as to have the primary gas enter that pipe; secondary gas is injected radially into the air stream at a downstream location relative to an atomizing nozzle. In using liquid propane (butane) to fire the burner, two stage fuel injection is used, with a stream of fuel being injected upstream and toward the burner centerline and another stream of fuel being injected downstream and outwardly away from the burner centerline.

Abstract: A combustion apparatus includes a moderator gas supply which is added to the fuel to be combusted by concurrent injection to form an intimate admixture as it enters the combustion chamber. Such intimate mixture facilitates a high degree of temperature control within the combustion zone of the flame itself, thereby protecting combustion components and at least reducing or eliminating the formation of thermal NO.sub.x.

Abstract: A method and apparatus are described for reducing NO.sub.x in a combustion zone such as a boiler by spatially selectively injecting a cooling fluid into the combustion zone so that the fluid is entrained to intersect an identifiable NO.sub.x producing zone. The cooling fluid can be water or a gas or mixture of them and whose temperature is sufficiently low or whose combined mass flow and temperature are sufficiently low so that the cooling fluid can reach the NO.sub.x producing zone and cool it to a temperature where the NO.sub.x production is significantly reduced. In one embodiment of the invention a cyclone boiler has a number of identifiable NO.sub.x producing zones. Several of these are targeted by spatially distinct cooling fluid streams placed at strategic locations.

Abstract: A fluid atomizer and spraying means which is made up of: a mixing chamber into which the fluid to be atomized and the atomizing gas are introduced and in which the fluid is admixed with and dispersed in the gas; a generally conical nozzle means extending from the mixing chamber through which the mixed fluid and gas are forced; and a chamber into which the atomized mixed fluid and gas is sprayed. The conical nozzle means is suitably a relatively narrow frustro-conical passageway which contains support-spacer means which is generally parallel to the direction of flow through the passageway. At least one such support-spacer means is provided which extends from the end of the passageway proximate to the mixing chamber to the end of the passageway proximate to the chamber into which the mixture is sprayed. The preferred use of this apparatus is in atomizing fuel oil with steam and spraying such atomized mixture into a combustion chamber where it is contacted with combustion air.

Abstract: A method an apparatus for flame stabilization in premixing burners in installations for heat generation for domestic and industrial purposes with reduced Nox and CO emissions and increased operational reliability includes a premixing burner through which a main combustion mixture is directed. A wall of the premixing burner has a plurality of radial openings located on at least one plane perpendicular to the flow direction of the burner for introducing a gaseous medium of fuel or a fuel and air mixture into the main flow and directed transverse to the main flow. Each of the radial openings is connected to a supply conduit to deliver the gaseous medium.

Abstract: A method for operating a furnace comprising generating NOx at a first NOx generation rate by combustion at a distance from the flue of the furnace and generating NOx at a second NOx generation rate, which is less than the first NOx generation rate, by combustion closer to the flue, and thereafter passing the NOx through the interior of the furnace to and through the flue while both the NOx generated by the first rate and the NOx generated by the second rate dynamically progress toward equilibrium.

Abstract: A process and apparatus for combustion of fuel which results in reduction of nitrogen oxides and carbon monoxides emissions. Fuel and primary air are preferably premixed and introduced into a combustion chamber. Secondary air is introduced through a plurality of secondary air ports which are positioned about a venturi nozzle or flame holder disk mounted with respect to a combustion chamber wall. The secondary air flowing through the secondary air ports forms relatively high velocity and momentum secondary air jets that promote rapid mixing of the fuel and primary air mixture into the secondary air flow, such that a combustion flame is established at a periphery of the secondary air jets.

Abstract: A process for minimizing the formation of nitrogen oxides in the disposal of industrial waste streams containing chemically bound nitrogen, the process comprising the steps of passing a combustion gas stream at about 1200.degree. F. to about 2000.degree. F. to a combustion chamber; mixing an industrial waste stream with a selected mixing ingredient to provide a waste stream mixture having a composition such that adiabatic combustion of the waste stream mixture would yield combustion products having a combustion temperature of about 1500.degree. F. to about 2000.degree. F.; injecting the waste stream mixture into the combustion chamber and contacting same with the combustion gas stream to combust the nitrogen containing compounds to form a composite combustion gas stream having a temperature of from about 1500.degree. F. to about 2000.degree. F. The composite combustion gas stream can be vented to the atmosphere after, preferably, passing same through heat recovery equipment.

Abstract: A low pressure atomizer is used for the atomization of liquids, such as atomization of fuels found in industrial burners. An atomizer body has an atomizing chamber therein and an annular liquid conduit having an annular diffusion member therein. The diffusion member is shaped to direct liquid passing thereby and into the atomizing chamber and forces the liquid to enter the chamber adjacent the walls thereof. The atomizer body has a first annular gas conduit and a tangential gas port connected between the annular gas conduit and the liquid conduit so that the gas impinges tangentially against the liquid to shear and rotate the liquid entering the atomization chamber. A second annular gas conduit has an angled open into the atomizing chamber to further shear the liquid and gas mixture in the atomizer chamber so that a low pressure atomizer atomizes a liquid with low pressure gas streams.

Abstract: A combustion method wherein fuel is mixed with an oxidant mixture comprising a defined concentration of argon and nitrogen and combusted resulting in reduced generation of particulate pollutants. The argon increases the mass and the nitrogen increases the volume of the oxidant improving the combustion reaction. Alternatively argon is mixed with fuel and the resulting mixture subsequently mixed with oxidant for combustion.

Abstract: In a premixing burner for the operation of an internal combustion engine, a combustion chamber of a gas turbine group or a firing system, which burner can be used for the combustion of fuels with very different properties, a diffuser (4) is arranged after a swirl generator (1), a convergent part (2) and a throat (3) for the supply of the fuel (9). The convergent part (2), the throat (3) and the diffuser (4) have a rotationally symmetrical configuration and the variation in cross section is adapted in such a way that no flow separation is possible at the wall. Gaseous fuels having a high flame speed are introduced counter to the swirl generated by the swirl generator (1). Gaseous fuels having a low flame speed are introduced in the same direction as the swirl generated by the swirl generator (1).

Abstract: A method and device for operating a combined burner for liquid and gaseous fuels for the purpose of generating hot gases functions to raise the lean stability limit of the gas flame without impairing the atomization of the liquid fuel and improve the regulating range of the burner. According to the invention, this is achieved when the inflow rate and/or swirl of the blast air (5) into the inner burner space (16) is controlled. To this end, the blast air (5), during operation with gaseous fuel (6), is throttled back by injection of pilot fuel into the blast air, and additionally swirled by swirl generators in the burner. In addition, active regulation of the blast air inflow rate is effected at the burner inlet during the use of both gaseous fuel and liquid fuel.

Abstract: A multi-directional after-air port for controlling air flow to a furnace in a staged combustion system has multiple sets of louvers or dampers oriented perpendicular to each other for improved control over combustion air-flow direction.

Abstract: A fuel injector has an inner pipe within an outer pipe. The distal end of the inner pipe is set back from the distal end of the outer pipe to create a flame stabilization and mixing zone. A combustible gas and air mixture injected through the outer pipe forms a flame shroud around a gas stream injected through the inner pipe. This injector provides increased flame penetration and improved NO.sub.x reduction particularly when used to inject a flame shrouded gas stream into regions of the furnace at which the flue gas is at a temperature not greater than 2400.degree. F.