Abstract: A burner tip having a converging portion with a multiplicity of ports. The ports are sized and positioned so that a substantially constant ratio is maintained between any selected cross-sectional flow area within the converging portion and the sum of the port areas downstream from that cross-sectional flow area, thereby maintaining a substantially constant pressure within the tip. A disk is positioned at a downstream portion of the converging portion to flatten the flame.

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 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: 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: A headspace autosampling apparatus (92) for generating and delivering gaseous samples to a gas chromatograph or other instrument includes a plurality of vials (98) in a carousel (150). The vials are delivered one at a time from the carousel through a vial delivery mechanism (160) to a heated zone (146) wherein the substances (94, 96) to be analyzed reach equilibrium with the headspace (100, 102) above the samples in the vials, preferably using the full evaporation technique (FET). The vials are generally cylindrical and extend horizontally to facilitate attainment of equilibrium rapidly upon heating. The vials are also preferably rotated about their longitudinal axis prior to sampling so as to achieve a film effect on the interior walls of the vials which further aids in attainment of equilibrium.

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: The invention relates to a water heating apparatus which uses a submergible, pressurized combustion chamber having multiple external heating surfaces, a forced draft burner and a flue collector that collects and passively recirculates a portion of the flue gases back into the burner air intake region. An improved burner array more completely mixes the combustible gases in the combustion region and operates over a wide range of input demands.

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: The burner comprises a tap-hole block (1), a burner body (C) substantially comprised of a tubular element (2), at least one injection blowpipe (3) extending through the burner body and into the cavity (P) of the tap-hole block (1), and unlockable quick mounting means (22, 20, 16, 23, 26, 28) for mounting the injection blowpipe (3) to the tubular elements (2) and the tubular element (2) to the tap-hole block (1). Application particularly to the oxicombustion in glass furnaces.

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: 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: Fuel is fed by a feeding pump to a pressurized container. A predetermined amount of fuel is kept constant in the container by a floater which carries a needle for opening and closing a return as required. In the pressurized container the fuel is kept by a compressor under compressed air pressure which may be regulated by a pressure control valve, so that when the valve is opened fuel and air both under the same pressure are pressed into a nozzle unit in which air is highly pressed in the fuel so that when it leaves the nozzle channel it expands in an explosive manner and bursts the fuel into fine droplets. Secondary combustion air from an air generator is blown into the flame perpendicularly to the axis of the flame and fed to the fuel-air mixture.

Abstract: A fossil fuel air burner nozzle is provided with a wall (22) at its inlet, in which are apertures (34) which narrow in a direction radially outward of the nozzle. Each aperture is axially aligned with a respective bluff member (18) at the outlet so as to deliver thereto a fuel air mix flow at a velocity which is graded in said radial direction so as to ensure flame retention on the bluff members (18).

Abstract: A burner is disclosed having a burner chamber with heavily insulated heat retaining walls and a series of off-center mixers located at one end thereof. A uniform concentration gas/air mixture to 50% additional fuel above the lean flammability limit coming from the mixer tubes is ignited in the burner chamber due to the recirculation of combusting gas and air back to the end of the burner chamber above auto the ignition temperature for the mixture. The particular mixture disclosed utilizes 0.55-0.7 equivalence ratio. With the present burner, oxidant and fuel are respectively supplied to each mixer by respective common oxidant and fuel plenums. In this way, fuel and oxidant are mixed near the point of combustion, enhancing safety and permitting the construction of larger burners.

Abstract: A burner provided for low NOx combustion of fuel with preheated combustion air in a combustion chamber of an industrial furnace and or a steam boiler has a plurality of fuel jets and at least a single air jet arranged to discharge the fuel and the preheated combustion air. The fuel jets and the air jet diverge from one another, provide dilution of fuel with combustion products, and generate multiple precombustion, combustion and post combustion reaction zones in the furnace.Thus, the burner provides the necessary process conditions and reaction zones required for minimizing the formation of prompt and thermal NOx in the precombustion and combustion reaction zones and for optimizing the decomposition of the formed NOx in the postcombustion reaction zones.

Abstract: A burner apparatus and method for reducing nitrogen oxides that are formed during combustion of gaseous fuel. Primary gaseous fuel and excess oxidant are premixed to form a fuel/oxidant mixture which is introduced into and combusted within a primary combustion zone. Primary combustion products are introduced into a secondary combustion zone. Secondary gaseous fuel is also introduced into the secondary combustion zone and is preferably mixed with the primary combustion products. The mixture of secondary gaseous fuel and primary combustion products is combusted in a secondary combustion zone. A portion of the secondary combustion products are internally recirculated into the secondary combustion zone. The overall combustion products can be externally recirculated and introduced into the primary combustion zone. A portion of the fuel/oxidant mixture, with or without the recirculated overall combustion products, can be bypassed around the primary combustion zone and introduced into the secondary combustion zone.

Abstract: An oxyburner (1) is associated with an opening (3) comprising a through passage (2) comprising a substantially cylindrical inlet region (5) receiving the downstream end of the oxyburner (1) and a substantially cylindrical outlet region (4) of a diameter D.sub.s and a length L.sub.s, the ratio D.sub.s /D.sub.e being comprised between 1.5 and 2.5 and the ratio L.sub.s /(D.sub.s -D.sub.e) comprised between 2 and 7. The speed of ejection of the oxygenated combustible gas is greater than 5 meters/second and the speed of ejection of the combustible gas is greater than the speed of the combustion-supporting gas.

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 premix burner assembly for heating the combustion chamber of a dryer for an HMA plant, soil remediation plant, or the like is designed to meet the very low emission limitations that are imposed in certain areas such as the southern portion of California. The burner assembly includes a burner, a primary nozzle, an air source connected to the burner, a fuel source, and a fuel injection system connected to the fuel source and to the burner. Premixing is achieved through the supply of a gaseous fuel from the fuel injection system into the burner upstream of the primary nozzle so as to lead to nearly complete premixing of the air and fuel prior to discharge into the combustion chamber, thereby permitting combustion of the fuel with only very small amounts of excess air. Burner efficiency is increased and emissions are further reduced by employing air distribution and control devices upstream of the fuel injection system and by carefully controlling the supply of both air and fuel to the burner.

Abstract: A burner apparatus and method for reducing nitrogen oxides that are formed during combustion of gaseous fuel. Primary gaseous fuel and excess oxidant are premixed to form a fuel/oxidant mixture which is introduced into and combusted within a primary combustion zone. Primary combustion products are introduced into a secondary combustion zone. Secondary gaseous fuel is also introduced into the secondary combustion zone and is preferably mixed with the primary combustion products. The mixture of secondary gaseous fuel and primary combustion products is combusted in a secondary combustion zone. A portion of the secondary combustion products are internally recirculated into the secondary combustion zone. The overall combustion products can be externally recirculated and introduced into the primary combustion zone. A portion of the fuel/oxidant mixture, with or without the recirculated overall combustion products, can be bypassed around the primary combustion zone and introduced into the secondary combustion zone.

Abstract: A premixing burner includes a pilot burner formed from two half conical shells and a plurality of main burners arranged around the pilot burner. Each of the main burners is formed with an cylindrical outer wall to contain a main flow. Each of the main burners includes a plurality of vortex generators arranged inside the cylindrical wall about a circumference. In addition, a venturi nozzle is disposed in each of the main burners downstream of the vortex generators. A fuel lance for each of the main burners injects one or both of a gaseous and liquid fuel into the burner as a secondary flow, and an outlet of the lance is positioned to inject the secondary flow in the region of the venturi nozzle having a maximum constriction.

Abstract: A burner is disclosed having a burner chamber with heavily insulated heat retaining walls and a series of off center mixer tubes located at one end thereof. A uniform concentration gas/air mixture to 50% additional fuel above the lean flammability limit coming from the mixer tubes is ignited in the burner chamber due to the recirculation of combusting gas and air back to the end of the burner chamber above auto the ignition temperature for the mixture. The particular mixture disclosed utilizes 0.55-0.7 equivalence ratio.

Abstract: The present invention relates to a device and a process for manufacturing synthesis gases through the combustion, under lack of oxygen, of a hydrocarbon fuel by use of a gaseous oxidizer, the device comprises primary injection means (2) producing, following an axis (14), a jet of fuel and of part of the oxidizer in a combustion chamber of a reactor, said jet comprising a main flame substantially originating at the level of the primary injection means (2) and extending from the primary injection means.The device also includes secondary injection means for injecting a complementary amount of oxidizer into the combustion chamber, the secondary injection means being arranged to direct the complementary amount of oxidizer into the jet at a distance from the primary injection means.

Abstract: The oxygen/fuel burner contains at least one first tubular component (2) conveying the oxidant and at least one second tubular component (3), for injecting the fuel into the oxidant flow,arrangd asymmetrically with respect to the first (2) so that the mixing region upstream of the flame contains a part where the ratio of the oxidant to the fuel is less than the soichiometric value.

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: This invention relates to fuel nozzles of the type that employ an entrainment fuel nozzle for initial, partial premixing of gaseous fuel and air. Such structures of this type, generally, use the gas jet to entrain surrounding air so that the fuel is somewhat diluted prior to injection into the combustor.

Abstract: In a conventional air burner for combustion of pulverized coal having a back and a front, and a coal feeding tube for the pulverized coal extending from the back to the front, an oil igniter connected to the front of the burner, an oil feeding tube connected to the oil igniter, the oil igniter when fired ignites the oil projecting a starter flame at the front of the burner, the starter flame ignites a continuous supply of the pulverized coal conveyed to the starter flame at the front of the burner to create a pulverized coal fueled flame, an improvement wherein a metal tube for conveying a suspension of fine-grained coal in a liquid or aqueous slurry is inserted through the burner and extends from the back to the front and wherein the metal tube is attached to a nozzle oriented and adapted to spray the aqueous slurry into the pulverized coal fueled flame.

Abstract: An oxy-fuel burner for a forehearth system comprising an oxygen conduit and a fuel conduit disposed concentrically within the oxygen conduit, forming an annulus between the fuel conduit and the oxygen conduit. The fuel firing end of the fuel conduit is recessed within the oxygen conduit at a distance from the oxygen firing end of the oxygen conduit. The ratio of the inside diameter of the oxygen firing end of the oxygen conduit to the inside diameter of the fuel firing end of the fuel conduit is in the range of about 2:1 to 8:1.

Abstract: Swirling-flow burner with improved design comprising U-shaped oxidizer and fuel gas injectors arranged coaxially at the burner face. The burner is further equipped with a bluff-body with static swirler blades extending inside the oxidizer injector.

Abstract: A gas burner comprising a gas nozzle 4 having a flame stabilizing plate 7 and gas jet orifices 8 at its top; and a burner corn 5 provided with a flame stabilizing plate 6 having secondary air passages 10 for combustion and primary air passages 9 for combustion formed between the flame stabilizing plate 6 itself and the outer periphery of the gas nozzle 4: the gas burner being characterized in that the primary air passages 9 for combustion are disposed so that primary air may pass between the flame stabilizing plate 6 and the outer periphery of the gas nozzle and may be mixed with a fuel gas 3 jetted through the gas jet orifices 8; the stream course of the mixed gas is changed to the periphery of the flame stabilizing plate 7 by this plate 7; and a part of the mixed gas is mixed with divided secondary air.

Abstract: An improved gas burner comprising a gas nozzle having a first flame stabilizer mounted to the front end thereof and a plurality of gas blow apertures arranged circumferentially therein adjacent to the first flame stabilizer, a second flame stabilizer having a plurality of secondary combustion air passages arranged in the circumferential end thereof and a primary combustion air passage arranged in the center thereof which is defined by the outer surface of the gas nozzle, and a burner cone accommodating the second flame stabilizer coupled to the inner wall thereof, said gas burner being improved for reducing unwanted nitrogen oxide and/or uncombusted gas, characterized in the positional relation between the flame stabilizer(s) and the gas blow apertures, the novel construction in which the shape of the flame stabilizer is designed for optimum function with association with its positional relation, the novel arrangement in which the flame stabilizer can be controlled for optimum positioning, and the improved bu

Abstract: A ceramic burner for a hot blast stove has a central gas duct that opens into the central zone of a burner crown and side air ducts on both sides of the gas duct which also open into the central zone. To improve combustion characteristics, there is a central air duct in the gas duct opening out within it. Air is supplied to the central air duct in an upward flow which exits in two opposing directions through side openings.

Abstract: A burner unit has a fuel dispersion arrangement at a burner head leading to a flame region which distributed fuel from longitudinal slots extending along trailing edges of spinner vanes of a spinner vane assembly. The spinner vane assembly is disposed transversely across a flow channel of combustion air past the burner head and has a function of deflecting the axial flow of the combustion air radially outward into a conical flow. The deflective air flow pressure distribution over the spinner vanes contributes to induction and mixing of the fuel with the combustion air as the combustion air enters the flame region of the burner. Combustion gases resulting from a combustible mixture achieved in this manner have resulted in emission products with pollutant levels within currently specified limits.

Abstract: Low NO.sub.x burners for the combustion of gaseous, liquid and solid fuels. The fluid dynamic principle of radial stratification by the combustion of swirling flow and a strong radial gradient of the gas density in the transverse direction to the axis of flow rotation is used to damp turbulence near the burner and hence to increase the residence time of the fuel-rich pyrolyzing mixture before mixing with the rest of the combustion air to effect complete combustion.

Abstract: An improved premixed gaseous fuel burner for a metal processing furnace includes an axially adjustable gas supply tube concentrically positioned within the burner body for delivering a flow of oxidant or other gaseous fuel component to the combustion chamber of the furnace. Axial repositioning of the air tube controls the spread of oxidant at the core of the flame, thereby controlling flame temperature and the operating environment of the combustion chamber and furnace. A flow mixer having a pair of helically arranged vanes provided in the annular space between the supply tube and the burner body imparts turbulent swirl to the premixture flow to cause enhanced mixing of the premixture. The gas supply tube is externally adjustable and includes a peep sight for externally viewing the flame in the furnace.

Abstract: A burner is disclosed having a burner chamber with heavily insulated heat retaining walls and a series of off center mixer tubes located at one end thereof. A uniform concentration gas/air mixture to 50% additional fuel above the lean flammability limit coming from the mixer tubes is ignited in the burner chamber due to the recirculation of combusting gas and air back to the end of the burner chamber above auto the ignition temperature for the mixture. The particular mixture disclosed utilizes 0.55-0.7 equivalence ratio.

Abstract: Regenerative glass melting furnace of the type having a batch section where glass is melted, a port neck where combustion air is introduced, and burners supplied by fuel inlet nozzles in the floor, the roof, and the lateral walls of the port neck.

Abstract: The gasification burner of this invention capable of maintaining a high combustion rate for a long period of time comprises a combustion chamber having a ceiling with a small hole in its center, a pre-mixing pipe fitted into the small hole and having a nozzle at its top, wherein the pre-mixing pipe and the combustion chamber are concentric, and the spread angle of the gas flow sprayed from the end of the pre-mixing pipe is between 10 and 40 degrees, so that the relationship between the bottom of the combustion chamber and the conical gas flow is regulated by keeping a good balance between the gasification rate of the powdered coke and the life of the combustion chamber.

Abstract: Improved methods and burner apparatus are provided for discharging mixtures of fuel and air into furnace spaces wherein said mixtures are burned and flue gases having low NO.sub.x content are formed therefrom. The methods basically comprise discharging a first fuel mixture containing a portion of the fuel and flue gases from the furnace space into the furnace space whereby the mixture is burned in a primary reaction zone therein and flue gases having low NO.sub.x content are formed therefrom, and then discharging the remaining portion of the fuel into a secondary reaction zone wherein the remaining portion of fuel mixes with air and flue gases to form a second fuel mixture which is burned in the secondary reaction zone and additional flue gases having low NO.sub.x content are formed therefrom.

Abstract: A burner and port combination for the combustion of a pulverized coal fuel plus air mixture comprises a throat and a burner nozzle positioned at a central area of the throat. The burner nozzle has an inlet for receiving the pulverized coal fuel plus air mixture and an outlet for discharging the pulverized coal fuel plus air mixture. A secondary air tube is positioned laterally adjacent the burner nozzle at each lateral side of the nozzle in the throat for providing a first portion of a secondary air to the throat. A plurality of vanes are positioned at an upper portion of the throat above the burner nozzle and the tubes and at a lower portion of the throat below the burner nozzle tubes for deflecting a second portion of the secondary air from the burner nozzle.

Abstract: A low NO.sub.x combustion system for reducing the production of nitrogen oxides in its emissions by using a low NO.sub.x adapter assembly in conjunction with a heat exchanger and a standard burner. The low NO.sub.x adapter assembly includes a low NO.sub.x manifold housing coupled between the heat exchanger and the burner, a flue gas recirculating fan coupled to the stack of the heat exchanger and the low NO.sub.x manifold housing and an operating control mechanism for controlling and regulating the primary air, the recirculated flue gas and the fuel to the burner and the low NO.sub.x manifold housing. NO.sub.x is reduced by supplying recirculated flue gas and a secondary fuel into the combustion chamber of the heat exchanger adjacent the outlet end of the burner via the low NO.sub.x manifold housing.

Abstract: Improved methods and burner apparatus are provided for discharging mixtures of fuel and air into furnace spaces wherein said mixtures are burned and flue gases having low NO.sub.x content are formed therefrom. The methods basically comprise discharging a first fuel mixture containing a portion of the fuel and flue gases from the furnace space into the furnace space whereby the mixture is burned in a primary reaction zone therein and flue gases having low NO.sub.x content are formed therefrom, and then discharging the remaining portion of the fuel into a secondary reaction zone wherein the remaining portion of fuel mixes with air and flue gases to form a second fuel mixture which is burned in the secondary reaction zone and additional flue gases having low NO.sub.x content are formed therefrom.

Abstract: A burner and burner firing method and system for a furnace combustion chamber in which a burner, having an ignition chamber for discharging an ignited combustible mixture of primary air and fuel into the furnace combustion chamber, and a plurality of nozzle ports for directing a high velocity stream of secondary air into the furnace combustion chamber in a direction generally parallel to the direction of flow from said ignition chamber, is operated in a first mode at furnace combustion chamber temperatures up to a transitional temperature by accelerating a burning mixture of fuel and air to moderately high velocities into the furnace combustion chamber, and in a second mode at furnace combustion temperatures above said transitional temperature by introducing a relatively low velocity stream of fuel mixed with a minor amount of air needed for stoichiometric combustion and accelerating a separate stream of air to high velocities into the furnace combustion chamber for mixture with said low velocity stream downs

Abstract: A mixing device is comprised of a pair of nested flow separator conduits (202, 204) with convolutions (201, 206) on the outlet ends (203, 205) and means of adjusting the relative position of the convolutions on one of the outlet ends relative to the convolutions on the other outlet end. The relative movement of the convolutions (201, 206) provides a method to modulate the rate of mixing between flows passing through the flow separator conduits (202, 204). Exemplary embodiments of the invention include application of the mixing device as a furnace (20) and as a gas turbine combustor (150).

Abstract: A burner (1) for feeding solid and liquid or gaseous fuel into a burning zone (8) of a kiln, for instance a rotary kiln, and comprising central duct (2) for liquid or gaseous fuel, a surrounding annular duct (3) for primary air and a further surrounding annular duct (4) for solid fuel is provided with an outer duct system (5) for feeding yet an amount of primary air into the burning zone (8), the duct system (5) being in the form of a heat exchanger for transferring heat from the inner kiln compartment surrounding the burner (1) to the primary air transported in the duct system (5) and thereby increasing the velocity of the air passing through the system without any corresponding increase of the fan power or the energy consumption of the kiln plant, but with a substantial decrease in the amount of primary air fed to the burning zone. The duct system (5) is separated from the remainder parts of the burner (1) by an insulating layer (7).

Abstract: The present invention provides a burner for burning a fuel in an oxidant. In accordance with the apparatus, a fuel nozzle is provided for producing a fuel jet of the fuel adapted to burn within the oxidant with the flame extending outwardly from the fuel nozzle and such that the particles of fuel become increasingly more buoyant along the length of the flame. A lower oxidant nozzle is located below the fuel nozzle for creating a lower oxidant jet of the oxidant that produces a low-pressure field below the fuel jet for downwardly spreading the fuel into the oxidant. Additionally, an upper oxidant nozzle is located above the fuel and lower oxidant nozzles for creating an upper oxidant jet of the oxidant to burn the increasingly more buoyant particles of the fuel. The velocities of the upper and lower oxidant jets can be adjusted independently of their mass flow rates to adjust the flame shape from sharp (convection dominated) to lazy (radiation dominated) without changing the stoichiometry of the flame.

Abstract: Improved low NO.sub.x formation gas burner apparatus and methods of burning uel are provided. The burner apparatus includes a refractory burner tile having a base portion and a wall portion, the wall portion extending into the furnace, surrounding a central area of the base portion and having exterior sides which are slanted. Means are attached to the burner tile for mixing a portion of the fuel gas with the air and discharging the resulting mixture into a primary burning zone in the furnace from within the space defined by the wall portion of the burner tile. At least one secondary fuel gas nozzle means positioned for discharging the remaining portion of the fuel gas adjacent to an external slanted side of the wall portion whereby the fuel gas mixes with flue gases and air in the furnace and burns in a secondary burning zone therein.

Abstract: Improved methods and burner apparatus are provided for discharging mixtures f fuel and air into furnace spaces wherein said mixtures are burned and flue gases having low NO.sub.x content are formed therefrom. The methods basically comprise discharging a first fuel mixture containing a portion of the fuel and flue gases from the furnace space into the furnace space whereby the mixture is burned in a primary reaction zone therein and flue gases having low NO.sub.x content are formed therefrom, and then discharging the remaining portion of the fuel into a secondary reaction zone wherein the remaining portion of fuel mixes with air and flue gases to form a second fuel mixture which is burned in the secondary reaction zone and additional flue gases having low NO.sub.x contents are formed therefrom.

Abstract: An improved process and apparatus for reducing NO.sub.x content of flue gas effluent from a furnace, the improvement comprising a burner assembly having a burner and flue gas recirculating system for collecting and passing internally recirculating flue gas into a combustion zone for reaction with a combustion flame. The burner preferably has a plurality of fuel dispensing nozzles peripherally disposed about the combustion zone to aspirate collected internally recirculating flue gas into the combustion zone, and has a plurality of fluid driven eductors to drive further amounts of collected internally recirculating flue gas into the combustion zone.

Abstract: Combustion method and apparatus establishing coherent jet oxidant flow within a cavity recessed from the main combustion area enabling operation without need for water cooling.