Abstract: An improved staged combustion method useful with oxy-fuel combustion and in a furnace which contains a charge, wherein substoichiometric combustion and secondary oxidant injection are carried out in an orientation which forms a more oxidizing atmosphere proximate the charge surface and oxidizing gas recirculates from the secondary oxidant stream to the charge surface and back to the secondary oxidant stream.

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 gaseous fuel (B) is fed to a a premixing burner which has a main line (10) for the feed of oxygenous gas (G) into at least one mixing zone and/or a combustion zone (VMZ, EMZ, VZ). In the process, at least a first portion of the fuel is fed to the main line (10), in which it is mixed with oxygenous primary gas (PG) inside at least one premixing zone (VMZ) and forms a premixture. The concentration of the fuel in the premixture (VM), under the respective operating conditions of the burner, is selected in such a way that the premixture lies outside the ignition limit. The premixture (VM) is fed to a final mixing zone (EMZ) and is mixed therein with the residual fuel (RB) likewise supplied and/or with oxygenous secondary gas (SG). The resulting final mixture (EM) is fed to a following combustion zone (VZ).

Abstract: A burner is provided with a central fuel outlet and a plurality of oxygen outlets shaped and positioned for creating a converging, rotating stream of oxygen which intersects with any fuel issuing from the fuel outlet. Such oxygen/fuel interaction results in two zones of combustion and a recirculation effect which assists in the complete or substantially complete combustion of undesirable exhaust gas components.

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: A furnace gas injection apparatus and process for delivering gaseous fuel to a furnace at a compound angle wherein one angle .alpha. of the compound angle is directed outwardly from the furnace burner centerline at an angle of between 75.degree. and 120.degree. to a line extending radially from the furnace burner centerline to the gas discharge openings of the gas injection means.

Abstract: A device for oxidizing a gas mixture that includes at least one hydrocarbon and oxygen. The device contains a porous solid that consists of zirconia. At least one metal having a catalytic oxidation activity, for example platinum or palladium, is deposited on the solid support. The device also contains an induced-air catalytic burner for the catalytic combustion of gaseous hydrocarbon mixed with atmospheric air and a member for dissipating the heat generated within the solid support. The device develops an average thermal power of at least 10 W/cm.sup.2 and an average temperature within the support of at least 700.degree. C.

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: A combustor for generating hot gas in order to rotate a turbine is able to burn fuel with a high vanadium content without emitting appreciable vanadium pentoxide to the turbine. The combustor includes a primary combustion zone for burning fuel in a rich fuel/air environment a quenching zone for cooling the hot gas and unburned fuel a secondary combustion zone for burning previously-unburned fuel. The fuel burned in the secondary combustion zone raises the temperature in the secondary combustion zone above the temperature of the quenching zone. The result of burning the fuel in a rich environment in the primary combustion zone is that most of the vanadium present in the fuel forms vanadium trioxide or vanadium tetroxide rather than vanadium pentoxide. Cooling the hot gas quickly in the quenching zone removes most of the remaining vanadium pentoxide by transforming it to vanadium trioxide or vanadium tetroxide.

Abstract: Waste/industrial effluents containing contaminating amounts of organic and/or inorganic species, for example effluents containing sulfate or sulfuric acid values, or effluents emanating from the production of methionine, are safely and effectively purified in high yield, by first establishing, in a first reaction zone, an axially helically descending flowstream defining a phase of combustion, this phase of combustion comprising ignited admixture of a first oxidizing fluid and a combustible fuel; ejecting the phase of combustion through a port of restricted flow passage to impart an axially symmetrical vortex flow thereto and flash-expanding same into a second reaction zone; introducing effluent to be purified into the axially symmetrical vortex thus formed; and also introducing additional oxidizing fluid into such axially symmetrical vortex, whereby the effluent is disintegrated into a multitude of droplets entrained in unit volumes of the phase of combustion and thermally treated in the second reaction zone.

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: A method is presented for stabilizing the flame on the tips of burner internals in a process for preparing synthesis gas by partial oxidation of a gaseous hydrocarbon-containing fuel. The method comprises supplying a gaseous hydrocarbon-containing fuel, a moderator gas and an oxidizer through a burner to a reactor, and adjusting the mass flow of the moderator gas such that the moderator gas concentration does not exceed a predetermined limit. The process conditions are effected such that the flame contacts the burner internal tips. In case of flame-lifting from the burner internal tips, the velocities and mass flows of the fuel and/or oxidizer and/or moderator gas are re-adjusted in such a manner that the flame is restabilized on the burner internal tips.

Abstract: A burner has a plate (21) with small openings (22) leading a first portion of the combustion air to mix with fuel and larger openings (24) for leading a second portion of the combustion air to mix with the burning fuel downstream of the position where the first portion of the air mixes with the fuel. The smaller openings (22) are sufficiently small for boundary layer effects to influence the ratio of the first portion to the second portion of the combustion air as the temperature of the air changes.

Abstract: The distribution-pressurized natural gas is supplied via a conduit arranged in the piston of an electrovalve in a nozzle of which the outlet leads to a cone which provides, with the nozzle, a ring-shaped opening which, connected to the atmosphere, acts as a secondary nozzle for injecting air into the gas flow. The cone is followed by a cylindrical element then by an abrupt widening section which opens into a heat exchanger which is in contact with a substrate impregnated with a catalytic material which oxidizes fuel gas. A small amount of air is sucked up by the widening and mixed with the gas. This mixture is then treated in the exchanger up to the transformation temperature of the sulphur-containing compound and the sulphur is then oxidized.

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: In a method of this invention, a first oxidant flow including oxygen and/or air, is injected into an exhaust gas flow from a primary burn zone in a furnace combustion chamber. The first oxidant flow is injected into the exhaust gas flow in a secondary burn zone downstream from the primary burn zone, but inside of the furnace chamber so that heat released from combustion of the first oxidant flow can be used for the purpose to which the furnace is applied. Also, the injection of the first oxidant flow into the secondary burn zone combusts fuel pollutants that might otherwise be released from the furnace into the atmosphere. The method can also include mixing a gaseous hydrocarbon fuel flow with the exhaust gas flow from the secondary burn zone to reduce the NO.sub.x, level in the exhaust gas. Also, the method can include mixing a second oxidant flow including air and/or oxygen, with the exhaust gas, preferably after reducing the NO.sub.x.

Abstract: An improvement of a coal firing device applied to coal gasifiers, boilers for power generation, etc. On the inner walls of a ceiling portion (4) of a firing furnace (3) and of a throat portion (2) thereabove, and of a diffuser portion (6) further thereabove, where necessary, plate-like vortex breaker(s) (1A, 1B) is/are provided. Vortex flow of gas in the vicinity of the inner wall surface around the throat portion (2) is thereby weakened and molten slag sticking on the wall surface is suppressed to be pushed up by the gas. There occurs neither staying of molten slag at the diffuser portion (6) nor scattering of slag, and blockade of furnace due to solid-phase slag does not occur.

Abstract: An improved staged combustion method useful with oxy-fuel combustion and in a furnace which contains a charge, wherein substoichiometric combustion and secondary oxidant injection are carried out in an orientation which forms a more oxidizing or a more reducing atmosphere proximate the charge surface than would be the case with a homogeneous furnace atmosphere.

Abstract: A novel burner and burner method has been invented which burns an ultra lean premixed fuel-air mixture with a stable flame. The inventive burning method results in efficient burning and much lower emissions of pollutants such as oxides of nitrogen than previous burners and burning methods. The inventive method imparts weak swirl (swirl numbers of between about 0.01 to 3.0) on a fuel-air flow stream. The swirl, too small to cause recirculation, causes an annulus region immediately inside the perimeter of the fuel-air flow to rotate in a plane normal to the axial flow. The rotation in turn causes the diameter of the fuel-air flow to increase with concomitant decrease in axial flow velocity. The flame stabilizes where the fuel-air mixture velocity equals the rate of burning resulting in a stable, turbulent flame.

Abstract: An over-fire air control system for a pulverized fuel furnace, in which a burner assembly is provided for discharging a fuel/primary air mixture along with secondary air to combust the fuel. The amount of primary air and secondary air discharge is controlled to achieve incomplete combustion, and an overfire air port is provided through which additional air is discharged to complete the combustion. The overfire air port receives two streams of air, one high in volume and low in velocity and the other low in volume and high in velocity. Dampers are provided for controlling the air streams to achieve optimum quantifies and velocities of the air. According to one embodiment, a source of one of the air streams is the primary air portion of the fuel/primary air mixture applied to the burner assembly. As a result, the formation of nitrous oxides are reduced and fairly precise air fuel ratios can be maintained despite variations in the quality of the fuel and the pressure and amount of primary air.

Abstract: A process and apparatus for combustion of a fuel/oxidant mixture in which at least a portion of the fuel is preheated and, thereafter, burned with any remaining portion of fuel in a flame having fuel-rich zones, thereby forming soot within the resulting flame to produce a luminous, high heat transfer, low NO.sub.x flame.

Abstract: A process and diluent injection burner apparatus is provided which is capable of reducing the nitrogen oxide content in a combustion effluent, the diluent injection burner assembly provided with a burner head having an air flow passage extending therethrough and primary and secondary fuel dispensing nozzles supported within the airflow passageway and adapted to inject fuel into a peripheral downstream end portion of the burner head. A diluent manifold assembly is supported by the burner head such that upon combustion of the fuel diluent is tangentially injected into the peripheral downstream end portion of the burner head relative to a flame envelope produced by ignition of the primary and secondary fuel so that a diluent shroud is formed about a base portion of the flame envelope.

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 process for producing energy from sulphur containing carbonaceous fuels comprises partially oxidizing the carbonaceous fuel to produce off gasses including carbon monoxide, hydrogen and hydrogen sulphide; removing hydrogen sulphide from the off gasses and combusting the off gasses from which the hydrogen sulphide has been removed to produce energy.

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 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: The invention is directed to a method and a device for improving combustion in combustion processes and to achieve cleaner emissions. An oxidizer in gaseous form is introduced to metal-containing surfaces or surfaces onto which oxidizers can deposit in the combustion area or its proximity so that a direct convergence with the fuel feed and its admixture with air is obtained. The regulation of the flow supply is effected with an engine feedback control system. The following are also effected by the control system: the gaseous flow, the flow speed and concentration according to the engine load, motor speed, temperature, fuel consumption and gaseous emissions.

Abstract: A nozzle adapted for use in a high excess air burner. The nozzle includes three combustion chambers and an outer flame retention ring for supporting combustion of gaseous fuel over a range of volumetric flow rates. Combustion air is staged to each of the combustion chambers and to the outer flame retention ring for mixing with the fuel to form a combustible fuel-air mixture. Combustion occurs in the first combustion chamber at relatively low flow rates of fuel. Combustion occurs in the second and third combustion chambers and the outer flame retention ring with increasingly higher fuel flow rates. The second combustion chamber is configured with a radially inwardly converging sidewall to provide for a smooth transition of the flame between the second and third combustion chambers.

Abstract: In a method of operating a multi-stage combustion chamber, having at least one primary burner (110) of the premixing type of construction, the fuel injected via nozzles is intensively mixed with primary combustion air inside a premixing space in advance of the ignition. Secondary combustion air is directed into a secondary combustion space (62) which is arranged downstream of the precombustion space (61). The primary burner (110) is a flame-stabilizing double-cone burner without a mechanical flame retention baffle, which is operated at the lower stability limit. The burnt gas is accelerated between precombustion space (61) and secondary combustion space (62). For the purpose of forming a self-igniting mixture, cooling air from the double-wall combustion-chamber boundary and additional fuel are introduced into the burnt-gas flow leaving the precombustion space.

Abstract: A method and apparatus for low NO.sub.x combustion in natural draft combustion chambers comprising staged-air combustion apparatus and process in which a fuel-rich, fuel/air mixture is introduced through a burner into a combustion chamber, forming a fuel-rich primary combustion zone flame. The fuel-rich primary combustion zone flame is attached to a flame guide disposed substantially parallel to the longitudinal axis of the primary combustion zone flame and extending from behind the burner. The flame guide also provides for removal of heat from the primary combustion zone flame. Secondary combustion air is introduced into the combustion chamber downstream of the burner to complete combustion of the fuel-rich primary combustion zone flame products. Internal recirculation of combustion gases within the combustion chamber into the fuel-rich primary combustion zone flame stabilize the fuel-rich primary combustion zone flame and contribute to emissions reduction.

Abstract: Method and apparatus for reducing NOX production in an air-oxygen-fuel combustion process by creating post mix oxy-fuel flame and introducing air around said oxy-fuel flame at an angle of greater than 0.degree. to 90.degree. to the longitudinal axis of the oxy-fuel flame.

Abstract: A staged oxy-fuel burner for producing a generally flat fuel rich flame overlying a highly radiative fuel lean flame, the burner having a fuel passage terminating in a nozzle, the fuel passage and nozzle having a generally elongated cross-section, a housing of complementary shape surrounding the fuel passage, so that when fuel is introduced into the fuel passage and an oxidizer is introduced into the passage defined by a space between the housing and the fuel passage a generally flat fuel rich flame is produced at the nozzle end of the fuel conduit and a staging nozzle for introducing oxidizer underneath and in a shape complementary to said fuel rich flame to produce a highly radiative fuel lean flame under said fuel rich flame.

Abstract: A glassmelting method employing reducing and oxidizing conditions generated by defined combustion arrangements enabling the processing of glassmaking materials while reducing NOx emissions which would otherwise result from, for example, niter decomposition. The NOx is reduced to nitrogen under the reducing conditions and kept from reforming in the oxidizing zone.

Abstract: A method and apparatus is disclosed for controlling staged combustion systems of the type used for combusting two reactants wherein at least one reactant is supplied as two flows, the first of which is combusted with the flow of the other reactant in a primary stage and the other of which is combusted with the exhaust of the primary stage in a secondary stage. In the present invention, the respective flows are monitored and controlled to provide a desired equivalence ratio for both the first stage and for the burner overall which is adaptable in response to variable input conditions. By controlling the flows in this way, a calculated energy output or adiabatic flame temperature can be produced. The present invention can also control the reactant flows to each stage in response to measured parameters such as flame temperature or emission levels. In this way, the flows can be varied in order to drive the measured parameters to a desired level.

Abstract: A method and apparatus for controlling NO.sub.x produced by a natural gas fired combustion source includes establishing a control curve for the combustion source for indicating NO.sub.x levels based on steam injection rates and fuel flow rates provided to the burners. The atomizing steam injection flow rate provided to the burner is measured as well as the fuel flow rate. A NO.sub.x level is determined for the combustion source based on the atomizing steam injection flow rate, the firing rate, and the fuel flow rate. NO.sub.x levels are lowered by adding atomized steam to the burners according to the pre-programmed control curve.

Abstract: A combustion method is provided for carrying out combustion with reduced generation of nitrogen oxides. The combustion method involves partially combusting a fluid fuel stream with a low velocity oxidant and thereafter mixing and combusting the resulting product with a secondary oxidant stream diluted with ambient gas. The velocity of the secondary oxidant stream is either increased to reduce the nitrogen oxides emission level or adjusted to provide the desired secondary oxidant/low velocity oxidant ratio which is useful for further decreasing the formation of nitrogen oxides. Normally, increasing the ratio and/or velocity further decreases the nitrogen oxides emission level. When liquid fuel is employed, it is atomized with atomizing fluid in such a manner to produce a liquid fuel stream having a very narrow spray angle. The production of such a stream allows the burner to be operated without water cooling.

Abstract: In a combustion process permitting reducing the production NO.sub.x, there is ejected via a burner (1) at least one flow of combustible gas, at least one flow of an oxygenated gas supporting combustion and at least one flow (10) of one of these gases in liquid phase. In an oxyburner, one portion (between 13 and 35%) of the oxygen is injected in liquid phase. In an aeroburner for natural gas, one portion (10 to 30%) of this latter is ejected in a coherent liquid jet. Use particularly in glass furnaces and heaters.

Abstract: An oxidant lancing nozzle and lancing method wherein first and second oxidant streams are injected into a combustion zone under defined conditions enabling the lancing of oxygen to augment a main combustion reaction with improved flame stability and unchanged or even reduced NO.sub.x formation.

Abstract: An oxy-fuel burner for producing a generally flat luminous flame, the burner having fuel passage terminating in a nozzle, the fuel passage and nozzle having a generally elongated cross-section, a housing of complementary shape surrounding the fuel passage, so that when fuel is introduced into the fuel passage and an oxidizer is introduced into the passage defined by a space between the housing and the fuel passage a generally flat luminous flame is produced at the nozzle end of the fuel conduit. A precombustor having a cross-sectional shape complementary to that of flame end of the burner can be disposed on the flame end of the burner housing to further enhance combustion and protect the burner from the furnace atmosphere.

Abstract: In order to improve the combustion of the liquid fuel (4) in such a burner (1) without influencing that of the gaseous fuel (7), the liquid fuel (4) is directed at high flow and swirl velocity into the settling chamber (13) of the airblast nozzle (2). Then the flow and swirl velocity is reduced and a thin fluid film is formed on the prefilming lip (15). The blast air (15) is directed with a quantity ratio of less than 1:1 to the liquid fuel (4) into the airblast nozzle (2) and separates small fuel droplets at the tip (27) of the prefilming lip (15).In a double-cone burner (1), the combustion mixture (28) is injected against the swirl of its main air flow (8) and at a spray angle (26) of less than or equal to 30.degree..

Abstract: The present invention relates to a fluid fuel burner with very low emission f nitrogen oxides, comprising, in known manner, means for injecting the fuel into a hearth at least one primary air supply conduit around said injection means, and at least one secondary air supply conduit located radially on the periphery outside the primary air supply conduit. According to the invention, said injection means comprise multiple orifices creating a plurality of independent divergent flames in the hearth, and the burner comprises as many secondary air supply injectors as there are said flames, each of said injectors being placed axially and angularly with respect to one of these flames, in a position such that it furnishes thereto an additional air fluid after a first phase of combustion.

Abstract: In a process for continuously mixing streams of at least two fluid media, in particular for use in reburning or progressive combustion and for secondary NO.sub..chi. -reduction in flue gases from industrial furnace plants an auxiliary gas stream is injected into a main gas stream by means of swirl-momentum nozzles which impart a characteristic axial impulse and an angular impulse to the fluid.

Abstract: A burner apparatus for the combustion of a fuel and an oxidizer includes a burner block having a fuel line for feeding fuel to a fuel port opening into a combustion chamber and a plurality of primary and secondary oxidizer lines positioned around the fuel line for feeding an oxidizer to a primary and secondary oxidizer port to the combustion chamber for combustion with the fuel from the fuel port. The primary and secondary oxidizer lines and ports are spaced around the fuel port so that controlling the oxidizer is used to change the position and shape of the flame in the combustion chamber. First and second oxidizer valves are located in the oxidizer feed lines and vary the amount of oxidizer fed through the oxidizer line so that the first and second oxidizer control valves for each set of oxidizer lines are spaced around the fuel port to allow both the position and the shape of the burner flame to be controlled.

Abstract: Method and apparatus for generating oxy-liquid fuel with lowered NO.sub.x products using low pressure oxygen to atomize liquid fuel and produce an oxy-liquid fuel flame and surrounding the oxy-liquid fuel flame by an oxidizer, confining the oxy-liquid fuel flame and oxidizer in a precombustor for a distance determined by the rate of flame propagation and the diameter of the pre-combustor.

Abstract: An industrial process burner which operates with optimal control of fuel/air mixing and reduced NO.sub.x emissions. The burner has a body formed with a primary fuel jet which is surrounded by inner and outer sets of air jets. The inner set of air jets directs air for mixing with the primary fuel jet. The outer set of air jets directs air which entrains a portion of combustion products for diluting the pre-combustion air/fuel mixture to lower the flame temperature and reduce NO.sub.x emissions. A secondary set of fuel jets directs fuel along a path apart from the primary fuel jet, and a set of additional air jets merges into and deflects air flow from the secondary jets inwardly to the base of the primary fuel jet for establishing a local combustion zone to promote ignition of the flame.

Abstract: Method and apparatus for safely combusting a fuel in such manner that very low levels of NO.sub.x and CO are produced. The apparatus comprises an inlet line (12) containing a fuel and an inlet line (18) containing an oxidant. Coupled to the fuel line (12) and to the oxidant line (18) is a mixing means (11,29,33,40) for thoroughly mixing the fuel and the oxidant without combusting them. Coupled to the mixing means (11,29,33,40) is a means for injecting the mixed fuel and oxidant, in the form of a large-scale fluid dynamic structure (8), into a combustion region (2). Coupled to the combustion region (2) is a means (1,29,33) for producing a periodic flow field within the combustion region (2) to mix the fuel and the oxidant with ambient gases in order to lower the temperature of combustion. The means for producing a periodic flow field can be a pulse combustor (1), a rotating band (29), or a rotating cylinder (33) within an acoustic chamber (32) positioned upstream or downstream of the region (2) of combustion.

Abstract: A gas burner comprising a housing with a front exit, a back surface, and an outer surface. The housing has a closed back surface at one end and an open exit at the other end. The housing is separated into a fuel-oxygen mixing chamber and a second chamber by a support plate. A multiplicity of jets passing through the support plate such that the fuel-oxygen mixing chamber is in communication with the second chamber through the jets. The fuel-oxygen mixing chamber has an inlet for a first-gas, usually a fuel gas, and an exit. The second chamber has an inlet for a second-gas, usually oxygen. The jets arranged such that each jet centerline is unique with respect to all other jet centerlines and each jet centerline is directed from the support plate to the housing exit.

Abstract: The invention relates to a process and apparatus for reducing pollutant gas emissions in the combustion of fuel, which utilize oxygen or oxygen-enriched air while avoiding the resulting disadvantages of high flame temperature and low gas momentum resulting in high NO.sub.x emissions. The invention provides a process of burning fuel, which simultaneously injects two jets of heated oxidant gas such as recirculated furnace gases and mixing such recirculated furnace gases with the oxidant into the furnace.