Abstract: Methods for cyclone boiler flame diagnostics and control, including methods for monitoring the operating state of a cyclone furnace using linear and nonlinear signal analysis techniques, including temporal irreversibility and symbol sequence. Adjustments may be made in the air flow distribution to optimize performance. Signals for the main flame and lighter scanners are relatively independent, thereby allowing for independent control of the primary air flow to the burner and secondary air flow to the barrel.

Abstract: Combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

Abstract: A burner system that utilizes a plurality of single stage rapid mix burner cells which are organized into one or more self-stabilizing matrices. The assemblage combines the advantageous operating characteristics of nozzle mix and premixed type burners and achieves extremely low NOx, CO, and hydrocarbon emissions.

Abstract: A burner assembly that produces very low NOx emissions includes a plurality of furnace gas openings for receiving a portion of furnace gasses back into a combustion cylinder. The burner assembly includes the combustion cylinder, a plurality of combustion air inlet conduits that extend into the cylinder and a plurality of fuel gas discharge nozzles that also extend into the cylinder. The burner assembly is mounted within a combustion chamber of a furnace, wherein the walls of the combustion chamber are provided with or are made up of heat transfer pipes.

Abstract: A gas burner for use in a furnace and a method of burning gas in a furnace, especially but not exclusively a process furnace used in an oil cracking or refining process. The gas burner comprises two passageways with adjacent outlets. The first passage way is in fluid communication with a source of pressurised fuel gas and has an aperture through which recirculated flue gas can enter the first passageway and the second passageway is in fluid communication with a source of air. In operation, fuel gas is injected into the first passageway and recirculated flue gas is thereby drawn into the first passageway so that it mixes with the fuel gas. Fuel gas is partially combusted and a mixture of partially combusted fuel gas and recirculated flue gas flows up the first passageway and comes into contact with air from the second passageway and combusts.

Abstract: A method for combusting a combustible fuel includes providing a vessel having an opening near a proximate end and a closed distal end defining a combustion chamber. A combustible reactants mixture is presented into the combustion chamber. The combustible reactants mixture is ignited creating a flame and combustion products. The closed end of the combustion chamber is utilized for directing combustion products toward the opening of the combustion chamber creating a reverse flow of combustion products within the combustion chamber. The reverse flow of combustion products is intermixed with combustible reactants mixture to maintain the flame.

Abstract: A burner for installation in a furnace having a combustion chamber defined by at least a furnace front wall, two side walls, a top wall and a bottom wall as well as heat transfer pipes through which a heat transfer medium flows and which are arranged on at least one of the top, bottom and side walls. A burner assembly is mounted to the furnace front wall and has a tubular member with an open distal end that is located inside the combustion chamber. The other end of the tubular member is attached to the furnace front wall. Several combustion air ports extend into the tubular member from the other, proximal end thereof and are coupled to a source of combustion air. Several fuel gas discharge nozzles also extend into the tubular member from the other end thereof and are coupled to a fuel source.

Abstract: A low NOx burner for installation on a furnace wall. The burner has an elongated tube connected to a combustion air supply, the furnace side end of which mounts a combustion air spinner that is spaced a substantial distance from the furnace wall. A plurality of typically six elongated air ports extend through the wall from the windbox of the furnace into the combustion chamber and supply most of the required combustion air. Downstream ends of the air ports are spaced from the furnace wall as well as from the spinner, and they are configured to bias the discharged air flow towards the spinner. A plurality of first fuel gas spuds with fuel gas discharge orifices is arranged about the spinner and discharges fuel gas into the combustion chamber downstream of the spinner. A second fuel gas spud is disposed in pockets between adjacent pairs of air ports which are closed against the furnace wall so that no combustion air flows through the pockets.

Abstract: A gas burner apparatus for discharging a mixture of fuel gas, air and flue gas into a furnace space of a furnace wherein the mixture is burned and flue gas having a low content of nitrous oxides and carbon monoxide is formed is provided. The burner tile includes at least one gas circulation port extending though the wall of the tile. The interior surface of the wall of the tile includes a Coanda surface. Fuel gas and/or flue gas conducted through the gas circulation port follows the path of the Coanda surface which allows more flue gas to be introduced into the stream. The exterior surface of the wall of the tile also includes a Coanda surface for facilitating the creation of a staged combustion zone. Also provided are improved burner tiles, improved gas tips and methods of burning a mixture of air, fuel gas and flue gas in a furnace space.

Abstract: A method and apparatus provide combustion in a radiant tube in first, second and third stages, with flue gas recirculation that begins at the second stage.

Abstract: Compact low NOx gas burner apparatus and methods for discharging fuel gas and air mixtures into furnace spaces wherein the mixture is burned in folded flame patterns and flue gases having low NOx content are formed are provided. A burner apparatus of the invention is basically comprised of a housing having a burner tile attached thereto and means for introducing air therein. The burner tile has an opening therein with a wall surrounding the opening which extends into a furnace space. The exterior sides of the wall are divided into sections by radially positioned baffles with alternate sections having the same or different heights and slanting towards the opening at the same or different angles. Primary fuel gas mixed with flue gases and air is discharged through the burner tile. Secondary fuel gas is discharged adjacent to the external slanted wall sections whereby the secondary fuel gas mixes with flue gases in the furnace space.

Abstract: Compact low NOx gas burner apparatus and methods for discharging fuel gas and air mixtures into furnace spaces wherein the mixture is burned in folded flame patterns and flue gases having low NOx content are formed are provided. A burner apparatus of the invention is basically comprised of a housing having a burner tile attached thereto and means for introducing air therein. The burner tile has an opening therein with a wall surrounding the opening which extends into a furnace space. The exterior sides of the wall are divided into sections by radially positioned baffles with alternate sections having the same or different heights and slanting towards the opening at the same or different angles. Primary fuel gas mixed with flue gases and air is discharged through the burner tile. Secondary fuel gas is discharged adjacent to the external slanted wall sections whereby the secondary fuel gas mixes with flue gases in the furnace space.

Abstract: A combustor assembly includes a combustor vessel having a wall, a proximate end defining an opening and a closed distal end opposite said proximate end. A manifold is carried by the proximate end. The manifold defines a combustion products exit. The combustion products exit being axially aligned with a portion of the closed distal end. A plurality of combustible reactant ports is carried by the manifold for directing combustible reactants into the combustion vessel from the region of the proximate end towards the closed distal end.

Abstract: The present invention is an air-staged low NOx burner for firing a gaseous fuel. The burner fires three stages, with the first stage of combustion taking place substantially within a burner cup section of a refractory baffle, the second stage of combustion taking place adjacent to the baffle and downstream of the baffle, and the third stage of combustion within a furnace. The flow of main combustion air adjacent to the baffle creates a negative pressure zone adjacent to the baffle. The present invention is also a method for low NOx staged combustion.

Abstract: The present invention provides a fuel feeding apparatus and method for improving the controllability of mixing process and mixing ratio of fuel and combustion air, and a combustion system and method for effecting new combustion properties. The fuel feeding apparatus of the combustion system has fuel feeding means, combustion gas extraction means, steam supply means, mixing means and fuel gas introduction means. The combustion gas extraction means extracts combustion gas of a combustion area therefrom. The mixing means mixes the fuel of fuel feeding means with at least one of combustion gas extracted from the furnace and steam of a steam generator. The fuel gas introduction means introduces a mixed fluid of combustion gas, steam and fuel to the combustion area as a fuel gas, and allows the fuel gas to be mixed with the combustion air.

Abstract: The invention relates to recirculation flow combustors having a generally curved recirculation chamber and unobstructed flow along the periphery of the boundary layer of the vortex flow in this chamber, and methods of operating such combustors. Such combustors further have a border interface area of low turbulence between the vortex flow and the main flow in the combustor, in which chemical reactions take place which are highly advantageous to the combustion process, and which promote a thermal nozzle effect within the combustor. A combustor of this type may be used for burning lean and super-lean fuel and air mixtures for use in gas turbine engines, jet and rocket engines and thermal plants such as boilers, heat exchanges plants, chemical reactors, and the like. The apparatus and methods of the invention may also be operated under conditions that favor fuel reformation rather than combustion, where such a reaction is desired.

Abstract: Method and apparatus for use in burners of furnaces such as those used in steam cracking. The apparatus includes a burner tube having a downstream end and an upstream end for receiving fuel and air, flue gas or mixtures thereof. A burner tip is mounted on the downstream end of the burner tube adjacent a first opening in the furnace, so that combustion of the fuel takes place downstream of the burner tip. At least one passageway has a first end at a second opening in the furnace and a second end in a primary air chamber adjacent the upstream end of the burner tube. The passageway also has structure for injecting steam into the passageway and a means for drawing flue gas from the furnace through the passageway.

Abstract: A generally toroidal counterflow heat exchanger is the main element of a combustor that operates at a micro scale. The combustor includes a central combustion region with openings to a reactant gas channel and an exhaust gas channel. The reactant channel and exhaust channels are coiled around each other in a spiral configuration that reduces heat loss. An electric current microgenerator is similar and also includes a thermoelectric active wall composed of n-type and p-type thermoelectric elements as part of a channel wall of the microcombustor. The thermoelectric active wall includes fins configured to increase the temperature differential across the thermoelectric elements relative to the temperature difference between the thermoelectric elements and the reactant and exhaust gases. A method of monolithically fabricating such microdevices by electrodepositing multiple layers of material is also provided.

Abstract: An improved burner assembly and process for operating same using a burner design that produces very low levels of undesirable nitrogen oxides is provided. The burner assembly premixes primary fuel and air in a venturi system and recirculates combustion gases back to the burner through a plurality of recirculation conduits where it is mixed with the premix of fuel and air and secondary air prior to combustion in a primary combustion zone. Rapid premixing of the primary fuel and air in the venturi system and the dispersion of the recirculated furnace gases is believed to result in lower peak flame temperatures and therefore minimizing the formation of the pollutants, such as nitrogen oxides.

Abstract: A burner assembly for a furnace or like device having a firebox defining a combustion zone. The burner assembly includes a first annular tile defining a centrally located path for a flow of combustion air and a second annular tile concentric with the first annular tile. The second annular tile has an internal diameter which is larger than an external diameter of said first annular tile, and the second annular tile is positioned in surrounding relationship relative to at least a portion of said first annular tile so that a ring-shaped conduit is defined therebetween. The tiles are adapted for placement in the combustion zone of the furnace with the conduit in direct fluid communication with flue gases surrounding the combustion zone. The arrangement is such that combustion air flowing along said path induces a flow of flue gas through the conduit for entrainment by the flow of combustion air.

Abstract: Compact low NOx gas burner apparatus and methods for discharging fuel gas and air mixtures into furnace spaces wherein the mixture is burned in folded flame patterns and flue gases having low NOx content are formed are provided. A burner apparatus of the invention is basically comprised of a housing having a burner tile attached thereto and means for introducing air therein. The burner tile has an opening therein with a wall surrounding the opening which extends into a furnace space. The exterior sides of the wall are divided into sections by radially positioned baffles with alternate sections having the same or different heights and slanting towards the opening at the same or different angles. Primary fuel gas mixed with flue gases and air is discharged through the burner tile. Secondary fuel gas is discharged adjacent to the external slanted wall sections whereby the secondary fuel gas mixes with flue gases in the furnace space.

Abstract: A thermal post-combustion device for the purification of exhaust air comprises an outer housing surrounded by an insulating jacket, a combustion chamber bounded by a combustion chamber housing and arranged within the outer housing, and a burner chargeable with fuel and that comprises a burner nozzle and a first flame tube that surrounds the burner nozzle and connects the space between the outer housing and the combustion chamber housing to the combustion chamber. The burner includes at least one further flame tube that is arranged completely within the combustion chamber, and the end of the first flame tube lying inside the combustion chamber is surrounded by a further flame tube of larger radius so as to form an annular gap between the first flame tube and the further flame tube. In this way a circulating flow of the combustion air becomes possible inside the combustion chamber, which flow is guided repeatedly through the annular gap and the flame of the burner.

Abstract: The present invention is a method and apparatus to improve the utilization of flow and power characteristics of a combustion air fan over the full range of burner operation. More specifically, it is an apparatus and a method of operation that uses a high flue-gas-to-air ratio over most of the boiler operating range to maximize thermal efficiency, but which switches to a lower ratio of flue-gas-to-air, or no flue gas in the limiting case, at the high end of the mass flow range of the burner to minimize the size of the fan housing and fan motor. When applied to current generation ULNBs, fan size can be reduced about 50% and operating power consumption can be reduced by about 50% without adversely affecting NOx emissions.

Abstract: Compact low NOx gas burner apparatus and methods for discharging fuel gas and air mixtures into furnace spaces wherein the mixture is burned in folded flame patterns and flue gases having low NOx content are formed are provided. A burner apparatus of the invention is basically comprised of a housing having a burner tile attached thereto and means for introducing air therein. The burner tile has an opening therein with a wall surrounding the opening which extends into a furnace space. The exterior sides of the wall are divided into sections by radially positioned baffles with alternate sections having the same or different heights and slanting towards the opening at the same or different angles. Primary fuel gas mixed with flue gases and air is discharged through the burner tile. Secondary fuel gas is discharged adjacent to the external slanted wall sections whereby the secondary fuel gas mixes with flue gases in the furnace space.

Abstract: A gas burner for use in a furnace and a method of burning gas in a furnace, especially but not exclusively a process furnace used in an oil cracking or refining process. The gas burner comprises two passageways with adjacent outlets. The first passage way is in fluid communication with a source of pressurised fuel gas and has an aperture through which recirculated flue gas can enter the first passageway and the second passageway is in fluid communication with a source of air. In operation, fuel gas is injected into the first passageway and recirculated flue gas is thereby drawn into the first passageway so that it mixes with the fuel gas. Fuel gas is partially combusted and a mixture of partially combusted fuel gas and recirculated flue gas flows up the first passageway and comes into contact with air from the second passageway and combusts.

Abstract: An apparatus for combustion of a fuel in stages having at least one wall enclosing a chamber and forming at least one fuel inlet opening, at least one oxidant inlet opening and a plurality of fuel/oxidant outlet openings. A recirculation sleeve is disposed on the fuel/oxidant outlet side of the chamber and is coaxially aligned with the center axis of the apparatus. A plurality of fuel distributors are disposed within the chamber, each fuel distributor having a fuel inlet and a plurality of fuel outlets, each of the fuel outlets being aligned with a corresponding one of the fuel/oxidant outlet openings. Also disclosed is a method for combustion of a fuel in stages.

Abstract: In a premixing burner (1) for a gas turbine or hot-gas generation for the combustion of liquid or gaseous fuel, in which fuel is mixed with combustion air (9a, 9b) in a burner interior (14), is fed to a combustion chamber (3) and is burnt in this combustion chamber (3), stabilization in the part-load model is achieved in a simple and efficient way in that means (15) are provided which make it possible to recirculate hot exhaust gas (17) out of the combustion chamber (3) into the burner interior (14) and to stabilize the flame by means of selfignition processes. The means (15) are preferably a recirculation line which picks up hot exhaust gas (17) from the outer backflow zone (10) and feeds it to the burner interior (14) in the region of a burner tip (2) facing away from the combustion chamber (3), additional fuel (pilot fuel 21) being admixed with the exhaust gas (17) in the recirculation line upstream of the feed to the burner interior (14).

Abstract: An improved process for heating furnaces using a burner design that produces very low level of undesirable nitrogen oxides is provided. The process recirculates a large volume of furnaces gases back to the burner where it is mixed with fuel gas in a plurality of recirculation ports prior to combusting with air in a primary combustion zone. Dispersion of the fuel gas in the recirculated furnace gases is believed to result in lower peak flame temperatures and therefore minimizing the formation of the pollutants, such as nitrogen oxides.

Abstract: An apparatus is provided including a furnace structure defining a reaction chamber in which oxidant and fuel are reacted to form combustion products and having an anchor surface having an opening through which the oxidant and fuel are introduced into the reaction chamber. The reaction chamber is configured to recirculate the combustion products back toward the anchor surface. The apparatus also includes an anchor outlet configured to create a layer of combustion products directed along the anchor surface under the influence of the recirculated combustion products. The apparatus further includes a primary outlet configured to direct primary fuel to flow into the reaction chamber through the opening and the layer of combustion products so as to ignite the primary fuel.

Abstract: A method and apparatus for combustion of a fuel in which a first-stage fuel and a first-stage oxidant are introduced into a combustion chamber and ignited, forming a primary combustion zone. At least about 5% of the total heat output produced by combustion of the first-stage fuel and the first-stage oxidant is removed from the primary combustion zone, forming cooled first-stage combustion products. A portion of the cooled first-stage combustion products from a downstream region of the primary combustion zone is recirculated to an upstream region of primary combustion zone. A second-stage fuel is introduced into the combustion chamber downstream of the primary combustion zone and ignited, forming a secondary combustion zone. At least about 5% of the heat from the secondary combustion zone is removed. In accordance with one embodiment, a third-stage oxidant is introduced into the combustion chamber downstream of the secondary combustion zone, forming a tertiary combustion zone.

Abstract: An improvement for an ejector having at least one discharge port effective for delivering a flow of fuel into a heating system such that flue gas in the heating system is entrained in the flow of fuel. The improvement comprises the ejector having an aerodynamic shape effective for increasing entrainment of the flue gas in the flow of fuel at the region of discharge adjacent the discharge port.

Abstract: This invention concerns a boiler fitted with a burner suitable for wall heaters or built-in kitchen heaters in which a mantle-shaped heat exchanger made of pipe elements connected in parallel and/or series divides the boiler chamber into a combustion chamber and an exhaust chamber. The heat exchanger has openings for hot flue gases distributed over its mantle. The burner head disposed in the combustion chamber is suitable for burning oil and has a flame tube with an axial flame opening and a flame baffle element disposed at a distance from the flame opening which is constructed so that the flame is diverted into the space between the flame tube and the heat exchanger. In addition, a fire chamber mantle can be disposed between the heat exchanger and the flame tube to protect the heat exchanger from direct contact with the flame.

Abstract: A method and apparatus for combustion of a fuel in which a first-stage fuel and a first-stage oxidant are introduced into a combustion chamber and ignited, forming a primary combustion zone. At least about 5% of the total heat output produced by combustion of the first-stage fuel and the first-stage oxidant is removed from the primary combustion zone, forming cooled first-stage combustion products. A portion of the cooled first-stage combustion products from a downstream region of the primary combustion zone is recirculated to an upstream region of primary combustion zone. A second-stage fuel is introduced into the combustion chamber downstream of the primary combustion zone and ignited, forming a secondary combustion zone. At least about 5% of the heat from the secondary combustion zone is removed. In accordance with one embodiment, a third-stage oxidant is introduced into the combustion chamber downstream of the secondary combustion zone, forming a tertiary combustion zone.

Abstract: Our cylindrical TPV generator uses low bandgap PV cells mounted on circuits in a polygonal array around an IR emitter. The combustion gases are completely contained within the radiant tube burner. The PV array is mounted inside a leak-tight envelope cooled on its outer surface by either water or air flow. Flanges on either end of this PV array container allow for hermetic seals. A folded back coaxial emitter support tube provides a long path length limiting thermal conduction along its cylindrical wall from the very hot emitter section to the cooled seal flange. In our improved cylindrical TPV generator, we provide for a low temperature catalytic after-burn by providing a perforated turnaround plate coupling between the inner disk stack and the outer disk stack. This perforated turnaround plate provides a small amount of combustion air for the after-burn. A catalyst coating can be provided on the hotter surface of the outer finned disks. The after-burn occurs in the outer finned disk stack.

Abstract: A round burner capable of being operated with reduced CO and NOx emissions includes a venturi tube positioned to direct a flow of air through the burner and into a combustion zone in a combustion chamber through an entrance in a wall of the combustion chamber. The venturi tube has inlet and outlet ends and a throat. The outlet end of the venturi tube has a larger internal diameter than either the inlet end or the throat and the same is positioned adjacent the entrance to the combustion chamber. The inlet end of the venturi tube is also positioned further from the entrance than the outlet end of the venturi tube. The burner may include a duct system that includes an inlet disposed in fluid communication with the combustion zone and an outlet disposed in fluid communication with the venturi tube adjacent the throat thereof.

Abstract: A burner arrangement includes a venturi cluster including a plurality of venturis arranged for parallel flow. The multi venturi arrangement utilizing pressurized fuel as the inducing fluid to induce a flow of air enables the provision of an ultra fuel lean premix of fuel and air. A central burner tube which extends outwardly beyond the delivery end of a primary burner tip and mounts a relatively small capacity nozzle at a substantial distance from the delivery end of the burner tip enabling the ultra fuel lean mixture to expand and slow down such that its linear speed does not exceed the flame speed of the mixture prior to by the flame of the spaced nozzle. A deflector may be positioned adjacent the nozzle to assist in stabilizing the flame after the expansion and slowing process has been completed.

Abstract: A burner assembly for a furnace or like device having a firebox defining a combustion zone. The burner assembly includes a first annular tile defining a centrally located path for a flow of combustion air and a second annular tile concentric with the first annular tile. The second annular tile has an internal diameter which is larger than an external diameter of said first annular tile, and the second annular tile is positioned in surrounding relationship relative to at least a portion of said first annular tile so that a ring-shaped conduit is defined therebetween. The tiles are adapted for placement in the combustion zone of the furnace with the conduit in direct fluid communication with flue gases surrounding the combustion zone. The arrangement is such that combustion air flowing along said path induces a flow of flue gas through the conduit for entrainment by the flow of combustion air.

Abstract: A compact heat source is provided which includes a bell-shaped or conical recuperator that surrounds a combustion chamber. The recuperator consists of parts that are axially tensioned against one another, so that a stable positioning of a partition wall provided with projections both on a bell-shaped outer wall and also on a bell-shaped inner wall is ensured.

Abstract: This invention relates to an apparatus and method for increasing the reactivity of a fuel/air mixture prior to homogenous combustion of the mixture. More specifically, this invention is a pilot for a gas turbine combustor which utilizes the heat of combustion within the pilot to increase the reactivity of a portion of the fuel/air mixture utilized by the pilot.

Abstract: A device for burning vented fuel has a housing defining and substantially enclosing a combustion chamber. The housing has an air inlet, a vented fuel inlet, and an exhaust gas outlet. A manifold burner is disposed in the combustion chamber and conveys the vented fuel into the combustion chamber. An ignition device is disposed in the chamber for igniting the vented fuel. The manifold burner and exhaust gas outlet define a direct exhaust gas path extending linearly from the manifold burner to the exhaust gas outlet. A deflection shield is disposed in the direct exhaust gas path, and is sized at least as large as the approximate size of the exhaust gas outlet, for substantially deflecting exhaust gas and heat produced by the combustion of vented fuel away from the exhaust gas outlet. The deflection shield is displaced from the exhaust gas outlet to create a gap for allowing exhaust gas to escape the combustion chamber along a nonlinear path.

Abstract: A burner/emitter/recuperator assembly for providing a high temperature radiant emitting surface, includes an elongated fuel pipe in communication with a fuel source and extending toward the combustion chamber, and adapted to flow fuel from the fuel source to a nozzle end of the fuel pipe proximate the combustion chamber, a primary air pipe disposed around the fuel pipe and in communication with a relatively cool primary air source, a nozzle end of the primary air pipe being substantially coincident with the nozzle end of the fuel pipe, and a recuperator for preheating secondary air disposed around a distal portion of the primary air pipe and in communication with a secondary air source and a swirler downstream of the recuperator.

Abstract: In a premix burner, the swirl-stabilized interior space (18) has a conical inner body (13) running in the direction of flow. The outer casing of the interior space (18) is pierced by tangentially arranged air-inlet ducts (11a, 12a) through which a combustion-air flow (16) flows into the interior space (18). The swirl flow (23) forming in the interior space (18) is enriched with a fuel via at least one fuel lance (17). The mixture of the two media is then formed in the downstream mixing tube (21). The mixing tube (21) then merges into a combustion space (31) via a jump in cross section, a backflow zone (32) forming in the region of the plane of the jump in cross section, which backflow zone (32) ensures the stability of the combustion.

Abstract: A high efficiency, Vortex Inertial Staged Air (VIStA) combustor provides ultra-low NO.sub.X production of about 20 ppmvd or less with CO emissions of less than 50 ppmvd, both at 3% O.sub.2. Prompt NO.sub.X production is reduced by partially reforming the fuel in a first combustion stage to CO and H.sub.2. This is achieved in the first stage by operating with a fuel rich mixture, and by recirculating partially oxidized combustion products, with control over stoichiometry, recirculation rate and residence time. Thermal NO.sub.X production is reduced in the first stage by reducing the occurrence of high temperature combustion gas regions. This is achieved by providing the first stage burner with a thoroughly pre-mixed fuel/oxidant composition, and by recirculating part of the combustion products to further mix the gases and provide a more uniform temperature in the first stage. In a second stage combustor thermal NO.sub.

Abstract: A combustion chamber is provided that has a vertically oriented body with an inner surface defining an inner combustion area. A burner is disposed adjacent one end of the body so that the flame of the burner when lit will extend into the combustion area. A first annular insert is disposed in the combustion area and generally surrounds the flame of the burner. The annular insert defines a first secondary gas introduction zone for introducing secondary gases into the combustion area so that the secondary gases can be oxidized by the burner flame. The insert has an inner surface presenting at least one opening for allowing fluid communication between the introduction zone and the combustion area. A second annular insert is disposed in the combustion area below the first insert. The second insert defines a secondary gas extraction zone and a second secondary gas introduction zone located below the extraction zone. The gas extraction zone and second secondary gas introduction zone are separated by a divider plate.

Abstract: According to the present invention, a catalyst combustion apparatus includes a ring-shaped catalyst body for catalytically burning the mixture of the fuel and the air, which is disposed in a combustion cylinder. In the combustion cylinder, a fuel nozzle and an inlet for the air are disposed at one end side of the catalyst body, and the premixing chamber is formed at the other end side. The fuel and the air are supplied from one end side of the catalyst body through a through-hole formed at a center portion of the catalyst body and is mixed in the premixing chamber. In the premixing chamber, a flow direction of the mixture is turned toward the catalyst body. A part of the exhaust gas is introduced into the air at one end side. In this way, it is possible to simplify and downsize the combustion apparatus, while securing the preheating effect of the air by the circulation of the exhaust gas.

Abstract: A low NO.sub.x burner includes a refractory lined plate with a refractory side facing a combustion chamber. A multiplicity of combustion air passages extend through the plate toward the combustion chamber. A multiplicity of spaced-apart primary fuel nozzles each have a discharge opening being surrounded by one of the combustion air passages for directing fuel therethrough to mix with combustion air passing through the air passages. A multiplicity of anchor fuel nozzles project through the plate for directing fuel into the combustion chamber. The anchor fuel nozzles are spaced apart from each other and from the combustion air passages. The flows of fuel and combustion air through the primary and anchor nozzles and the air passages into the combustion chamber are controlled to generate a flame. In applications that require low excess air, such as boiler applications, the burner is modified by providing a secondary fuel and flue gas injection assembly to form a two-stage burner.

Abstract: A low NOx burner having a burner body, to which an electric fan for supplying air for combustion is connected and which includes an exhaust gas recirculation passage for supplying combustion gas from the burner body to air for combustion, the low NOx burner including an exclusive exhaust-gas recirculation fan provided for the exhaust gas recirculation passage and arranged to forcibly recirculate exhaust gas, and a bypass passage formed between the exhaust gas recirculation passage and a passage for air for combustion formed in the burner body.

Abstract: The operational life of a synthesis gas generation reactor burner nozzle is improved, at least about 14%, by a faired lip around the nozzle discharge orifice projecting about 0.95 cm from the nozzle end face. The lip is faired with a 45.degree. conical angle from the nozzle face. A smooth transition of recirculated gas flow across the nozzle face into the reactive material discharge column is believed to promote an attached static or laminar flowing boundary layer of cooled gas that insulates the nozzle face, to a degree, from the emissive heat of the combustion reaction.

Abstract: A gas fired burner is provided for use in applications such as chemical process furnaces for process heaters in refineries and chemical plants, and the like. The burner is provided with a plurality of fuel gas inlets for enabling manipulation of the flame shape and combustion characteristics of the burner, based upon variation in the distribution of fuel gas between the various fuel gas inlets.A combination pilot and flame holder for a burner, such as may be used in process heaters and furnaces for refineries, chemical plants and the like, is also provided. The pilot is mounted atop a supply pipe for premixed fuel and air, which is positioned in the bore of a burner quarl. The pilot includes a radially outwardly extending flange which is upstream of a surface combustion flame holder for establishing a radially directed surface combustion flame.The present invention also provides a low-emissions burner and pilot system for use in such process heaters and furnaces.

Abstract: A gas fired burner is provided for use in applications such as chemical process furnaces for process heaters in refineries and chemical plants, and the like. The burner is provided with a plurality of fuel gas inlets for enabling manipulation of the flame shape and combustion characteristics of the burner, based upon variation in the distribution of fuel gas between the various fuel gas inlets.A combination pilot and flame holder for a burner, such as may be used in process heaters and furnaces for refineries, chemical plants and the like, is also provided. The pilot is mounted atop a supply pipe for premixed fuel and air, which is positioned in the bore of a burner quarl. The pilot includes a radially outwardly extending flange which is upstream of a surface combustion flame holder for establishing a radially directed surface combustion flame.The present invention also provides a low-emissions burner and pilot system for use in such process heaters and furnaces.