Abstract: In a burner for operating a combustion chamber, which burner essentially comprises a swirl generator (100) and a mixing section (220) arranged downstream of the swirl generator, this mixing section acting upstream of a combustion chamber (30), the swirl flow induced by the swirl generator (100) is directed via transition passages (201) into the mixing section (220). At the outlet of a mixing tube (20) belonging to the mixing section (220), the burner front (70) of the mixing tube (20) is provided with at least one torus-like notch (71) on the combustion-chamber side. Thus the stability of the backflow zone (50) can be intensified, which has a positive effect on the combustion from all aspects.

Abstract: In a combustion chamber of a gas-turbine group which essentially comprises a mixing section (2) for premixing an air/fuel mixture (16) and a downstream combustion space (3), a jump (5) in cross section is provided at the transition between the two said flow sections (2/3). This jump (5) in cross section induces the cross section of flow of the combustion space (3) and at the same time forms outer recirculation zones (10) in the combustion space (3). Flow passages (4) branch off in the end phase of the mixing section (2), which flow passages (4) then lead into the outer recirculation zones (10). A portion (9) of the air/fuel mixture flows out of the mixing section (2) through these flow passages (4) and into the outer recirculation zones (10), the portion being enriched here with an additional fuel (6). This fuel (6) is introduced via a circular line (19) provided with bores (18).

Abstract: A device for an oil burner has a ceramic tube (1) inside which a shorter tube (61) is arranged, so that there is a slot between the tubes. The device stands freely in the combustion room of the boiler, and it is coaxial with an oil burner (66) that is mounted in the boiler room wall. Combustion fumes mixed with fresh air from the fan of the oil burner is sucked into the slot that ends inside the ceramic tube. The oil burner flame in the inner tube (61) heats this inner tube that in turn heats the air that is sucked through the slot and is secondary combustion air. The slot has screw-formed ridges that impart a heavy rotation to the secondary air; a rotation that is counter to the rotation of the primary air of the burner. Since the secondary air is hot and rotates heavily, the final combustion will be very efficient.

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 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: A gas burner for discharging a mixture of a gaseous fuel and combustion air into a combustion chamber wherein the mixture is burned and flue gases are formed comprises a burner body having a peripheral wall defining a combustion air supply passage having a central axis and having an orifice communicating with the combustion chamber. Primary gaseous fuel is injected in a central part of the combustion air supply passage, and secondary gaseous fuel is injected through pipes in the combustion air supply passage peripherally distributed about the primary gaseous fuel injection. Conduits for recycling the flue gases are disposed in the combustion air supply passage and associated with the secondary gaseous fuel injection. The secondary gaseous fuel is injected into the conduits, the conduits have an axis extending parallel to the central axis and an orifice along their axis at one end thereof, the orifice communicating with the combustion chamber.

Abstract: Gas phase combustion producing lower emissions in gas turbines is stabilized in a lean pre-mixed combustor, by flow of the fuel/air mixture through a catalyst which is heated by contact with recirculated, partially reacted combustion gases.

Abstract: A radiation gas burner comprises a burner stone having an axis and a front surface over which a flame is distributed and which is heated by the flame so as to radiate heat, the burner stone being ring-shaped, an outlet pipe arranged radially inwardly of the burner stone and having an inner cylindrical space with an axially rear inlet and an axially front outlet, means for supplying fuel into the rear inlet of the inner cylindrical space of the outlet pipe, first passage means extending from the front surface of the burner stone and through the burner stone rearwardly, second passage means through which a primary air is supplied into the rear inlet of the inner cylindrical space of the outlet pipe to form a fuel-gas mixture which is supplied through the outlet pipe and exits through the front outlet, and third passage means through which secondary air passes through the burner and exits at the front surface, the first passage means for recirculating combustion products through the burner stone communicating wi

Abstract: A gas burner is described, provided with a connection for supplying a mixture of combustible gas and combustion air, and a burner pack comprising a plurality of stacks of at least one metal plate which is deformed transversely to its flat plane, and at least one flat metal plate on both sides of each deformed plate, which stacks of burner plates are separated by a solid filler and said plates with their main surfaces being parallel to the flow direction of the gas/air mixture, wherein per stack the flow direction of the gas/air mixture from the flow channels bounded by said deformed plate and said flat plates is the same.According to the invention, each stack of burner plates comprises two or more deformed plates.

Abstract: In the combustion chamber of a gas turbine, at least one premixing burner (110) is arranged in a dome (51) communicating with a plenum (50). Said premixing burner (110) is fastened on the outlet side to a front plate (52) limiting the combustion space (58) of the combustion chamber. The premixing burner procures the combustion air from the dome. The fuel injected via nozzles is intensively intermixed with the combustion air within a premixing space of the burner prior to ignition.There is provided a jet injector (53) which opens into the dome (51) and of which the central nozzle (54) is connected to the combustion space (58) via an orifice (55) in the front plate (52) and of which the annular space (56) surrounding the central nozzle is loaded with a propellant.

Abstract: A burner with a burner head (B) and a flame tube (F) is provided, with the burner head (B) having a concentric outlet arrangement of air and fuel feed nozzles. Following this a mixture of low-nitrogen air and fuel is produced, which is ignited in a chamber (11) in the interior of a hollow body (20). Hard-to-burn, noncombusted gas compounds flow upon exiting from the hollow body (20) along the exterior surface thereof back into the region before the hollow body (20) and flow again together with low-nitrogen air into the chamber (11) for combustion. This additional combustion increases the energy yield of the fuel and reduces the quantity of pollutants in the exhaust.

Abstract: A flue gas recirculation burner providing reduced No.sub.x emissions uses a cylindrical tangential mixer to separately receive combustion air and flue gas through axial inlets. The mixed air and gas pass through a vaned diffuser which continues the tangential flow pattern, and thereafter fuel is introduced tangentially and combustion occurs.

Abstract: The invention relates to an apparatus comprising a reactor, elongated along one axis, preferably of square or rectangular cross section. The reactor has, at one extremity, at least one supply line for at least one reactant and at least one evacuation outlet at the other extremity for removal of produced effluents. In a first zone (near the first extremity of the reactor), a plurality of heat exchangers, substantially parallel to each other, are disposed in substantially parallel layers perpendicular to the reactor axis, thereby defining spaces or passages for circulation of reactant(s) and/or effluents between the heat exchangers and/or layers formed by the heat exchanger. The heat exchangers are adapted to exchange heat in the passages through successive transverse sections, which are independent and substantially perpendicular to the reactor axis.

Abstract: A burner for combusting gas and/or liquid fuel and air in an enclosure includes a burner block of non-combustible material, such as ceramic material, having a central opening therethrough communicating with a combustion zone. The burner block has a plurality of spaced apart recirculation gas passageways paralleled to and spaced from the central opening, each of the recirculation gas passageways having an injection passageway communicating with the block member central opening. Fuel, which may be liquid and/or gas, is injected into said burner block central opening. Venturi action causes furnace gas to be drawn from the cool fringes of the combustion zone through the recirculation gas passageways for passage back into the central opening wherein air and fuel are thoroughly mixed and cooled for combustion within the enclosure. This recirculation system serves to reduce the temperature and oxygen content of the local combustion process to thereby reduce NO.sub.x production.

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 two stage rapid mix burner provides apparatus and method which significantly reduce the burner size of a rapid mix burner, and/or the burner pressure drop, while maintaining the rapid mix feature and stability of the basic rapid mix design. The burner can also be easily altered to fit in non-circular geometries, such as a corner or tangential fired boiler. The invention uses a circular basic rapid mix burner located internally of a larger burner which can be non-circular. The inner burner provides the flow of hot gases which stabilizes the outer burner. In effect, the combustion gases produced in the inner burner replace the strong internal recirculation flow generated by the basic RMB as an ignition source for the outer burner flow.

Abstract: The invention relates to a combustor, such as a burner or a cylinder of an engine with internal combustion, where combustion fluid passing through a slit (2,3; 6,7; 8,9; 11,12; 21,23; 31; 36,37; 39; 45; 48,49; 54; 61; 70,71,73,78; 96'; 109,110; 81; 124; 128), which may be straight as well as ring-shaped, is ignited in a space which allows for the development of turbulence. Said development of turbulence is caused by providing that bD/.nu.>1000, and preferably >2000, where b represents the width of the slit, D the distance between two consecutive slits or the width of the space and .nu. the kinematic viscosity of the supplied combustion air. In accordance with further embodiments of the invention, guiding members are placed to sustain said turbulences and/or to feed combustion gases back to the ejected peel-shaped jet. Thus a very low NOx value is obtained and it is likewise possible to construct a stable burner with a very wide adjustment range.

Abstract: A process and apparatus for cyclonic combustion with ultra-low pollutant emissions and high efficiency wherein a fuel and primary combustion air mixture is tangentially injected into a reducing primary combustion zone of a cyclonic combustor. The primary combustion air is injected into the reducing primary combustion zone in an amount equal to between about 30% and about 90% of a stoichiometric requirement for complete combustion of the fuel. Secondary combustion air is tangentially injected into an oxidizing secondary combustion zone of the cyclonic combustor, in an amount equal to between about 10% and about 90% of the stoichiometric requirement for complete combustion of the fuel. Primary combustion products from the reducing primary combustion zone are mixed with the tangentially injected secondary air for completing combustion within the oxidizing secondary combustion zone.

Abstract: A gas-fired burner incorporating an air driven jet pump for mixing air, fuel, and recirculated flue gas with reduced heat loss from the recirculated flue gas is disclosed. The burner is configured for the staged introduction of combustion air to provide a fuel-rich combustion zone and a fuel-lean combustion zone. Internal flue gas channels deliver cooled flue gas to the primary fuel-rich combustion zone. A valve assembly may be provided to control the flow of flue gas. Secondary air channels concentrically arranged within the flue gas channels deliver superheated, staged air to the secondary fuel-lean combustion zone. Heat is transferred from the hot flue gas to the counterflowing cooler secondary air. The burner achieves reduced NO.sub.x emission levels in high temperature applications which use preheated combustion air with no or minimal loss in thermal efficiency from flue gas recirculation.

Abstract: A forced draft burner apparatus and method providing extremely low NO.sub.x, CO and hydrocarbon emissions, while maintaining the desirable features of a nozzle mix burner. This is accomplished by injecting the fuel gas in a position that would be typical for a nozzle mix burner, while generating such rapid mixing that, effectively, premixed conditions are created upstream of the ignition point.

Abstract: A burner assembly has a combustion chamber in which combustion takes place in an elongate centrally disposed combustion tube. An outer housing encases the combustion tube and provides an annular space between an inner wall of the housing and the combustion tube. Part of the exhaust gases exiting from the combustion tube are diverted from the downstream end thereof to be returned through the annular space to the upstream end of the combustion tube. Fuel is injected into the diverted exhaust gases, volatilized when in liquid form and mixed with the diverted gases. The fuel and gas mixture is further combined with a buffer gas and becomes entrained into and mixed with a high velocity of combustion air which is injected into the upstream end of the combustion tube. The flame temperature may be monitored and the quantity of the buffer gas added may be controllably varied based on temperature readings from the monitoring process to minimize the generation of nitrous oxides.

Abstract: An indirect heater for heating air to be used for drying, curing or heating having an enclosure housing a circulation fan, filter bank, heat exchanger module and a burner. The heat exchanger has a bundle of tubes received between a pair of spaced apart headers. A cylindrical burner tube extends through one header and the tube bundle and opens into the other header. The burner flame and gaseous combustion products are discharged into a replaceable sacrificial sleeve that is telescopically received in the burner tube. A fan recirculates the heated gases through the interior of the sleeve, burner tube and the tubes of the bundle to increase heat transfer to the exterior air. The enclosure has a base, two pairs of opposed sidewalls and a top wall overlying the sidewalls. Each sidewall has an inner skin, a framework of trusses, an outer skin and insulation between the skins.

Abstract: In order to improve a burner for generating hot gas having a burner pipe, comprising a support pipe followed by a flame pipe, a nozzle arranged in the support pipe, a fuel jet exiting from the nozzle, a shield separating a precombustion chamber and a combustion chamber from one another in the burner pipe, the shield having a central passage penetrated by the fuel jet, recirculation openings arranged in the flame pipe and allowing an outer recirculation of cooled flue gas and an element for suppressing the outer recirculation during a starting phase of the burner, such that a reliable suppression of the outer recirculation during the starting phase is possible it is suggested that the element for suppressing the outer recirculation be arranged within the burner pipe and be controllable via a control means guided through an interior of the support pipe.

Abstract: A regenerative burner having heat storage units with combustion effluent/combustion air ducts therethrough, fuel intake means and a burner body, wherein the burner is designed to suppress NOx formation and to control flame shape and characteristic in the regenerative system during combustion. The regenerative burner may include a burner baffle, or may include a plurality of gas jets entrained in generally converging fashion for control of the flame charactaristics and shape dispositive of NOx formation. The burner may provide for staged combustion, either by means of sequential fuel injection or sequential provision of combustion air, or the burner may depress NOx formation by vitiation of combustion air with products of combustion. The present regenerative burners suppress NOx formation yet preserve the remaining characteristic features of regenerative systems.

Abstract: A method for two-stage combustion in which a mixture of fuel and primary combustion air is burned in a primary combustion zone, the primary combustion air comprising less than a stoichiometric requirement for complete combustion of the fuel, a portion of cooled partial combustion products formed in the primary combustion zone is recirculated from a downstream end of the primary combustion zone to an upstream end of the primary combustion zone, secondary combustion air is introduced into a secondary combustion zone downstream of the primary combustion zone, a portion of the heat from the primary combustion zone is removed, cooling the partial combustion products formed therein, and the heat is transported away from the combustion process. An apparatus for two-stage combustion in accordance with this method is also disclosed.

Abstract: To provide gasification of liquid fuel which is admitted by an atomizing nozzle (11, 13) into a gasification space (66). A deflection element (31) is located spaced from an air inlet (55) in order to deflect the mixture of air, recirculated combustion gases and gasified fuel in the gasification space. A flame tube (21) provides for a first (I) recirculation path for hot gases towards a recirculation openings (49). A second recirculation path (II) extends through openings (57, 61, 59) into the deflection element itself which, preferably, is a hollow, essentially shallow conical deflection structure. The deflection element in combination with the flame tube (21) causes recirculation of gases through the first recirculation path (I) back into the gasification space (66). Thus, all structural elements of the gasification space are subjected to recirculated hot combustion gases, so that no droplets from the atomizing burner (13) can adhere, and coke on structural elements.

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 method for generating heat by flameless combustion of a fuel in a gas flow having an oxygen content, includes passing a gas flow through at least one heating device, along at least one delivery device for fuel, and along at least one catalytically active element. A predominant part of the gas flow is passed through a loop while passing through a feed apparatus and along the at least one catalytically active element. A gas having an oxygen content is fed into the loop, and some of the gas flow is discharged from the loop. Fuel is admixed with the gas flow only to such an extent that a resultant fuel-gas mixture is not itself ignitable. An apparatus for introducing heat into a component, includes a gas carrying system for conducting a gas flow carrying heat produced by flameless combustion of a fuel. The gas carrying system has at least one loop, a delivery device for delivering fuel, a gas inlet, and a gas outlet.

Abstract: A radiation gas burner has a gas nozzle for supplying gas, an injector for injecting gas from the gas nozzle, an outlet pipe to which gas is supplied by the injector, a reflector cooperating with the outlet pipe, and a burner stone, the burner stone having at least two layers including a front layer composed of a refractory material with additives increasing the degree of blackness of the refractory material.

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: A jacketed jet radiant heater for an industrial process furnace as a frame tube composed of axially aligned pipe pieces abutted on one another that are held together by clasps on the outside of the flame tube that have studs which protrude into holes in adjacent pipe pieces and have a head portion which serves to center the flame tube within the jacket tube. The clasps make it possible to provide exhaust gas releasing slots between some of the pipe pieces of the flame tube and thereby avoiding local overheating of the jacket tube.

Abstract: A multiple purpose burner process and apparatus in which a burner assembly having a burner member defining a burner throat bore extending therethrough and forming an ignition zone and at least one mixing zone in the burner throat bore, the total combustion air passing through the burner throat bore. A minor portion of fuel gas as ignition fuel produces a continuous ignition flame in the ignition zone, and plural meter channels extending through the burner member communicate with the mixing zone to pass an admixture of a diluent gas with the remainder portion of the fuel, as a primary fuel stream, to the mixing zone for forming with the remaining combustion air a primary fuel/diluent/combustion air mixture, and the primary fuel/diluent/combustion air mixture is ignited by the ignition flame in the mixing zone.

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 method and apparatus for recirculating flue gas in either a vertical or a horizontal pulse combustor which is dedicated to deliberate one-stage pulse combustion. At least one combustion chamber wall defines a mixing region and a combustion chamber which is adjacent the mixing region. A fuel inlet conduit or a fuel/air inlet conduit is used to supply fuel into the mixing region. An air inlet conduit or a fuel/air inlet conduit is used to supply air into the mixing region. Air valves are in communication with the fuel inlet conduit, the air inlet conduit and/or the fuel/air inlet conduit. An ignition source is positioned within with mixing region for igniting the air/fuel mixture and beginning the pulse combustion process. An exhaust system removes flue gas containing products of pulse combustion. A portion of the flue gas produced during pulse combustion is then recirculated to the mixing region.

Abstract: The process for the continuous combustion of fluid fuel, for example fuel oil or gas, comprises the flow of several air jets through the opening of a screen, these air jets being arranged in such a manner that a multidimensional layering of mixtures of fuel, recirculated flue gas and air in the axial, radial, and circumferential directions is obtained within a fire tube. In this manner, the amount of noxious combustion products is reduced to values which are lower than the most severe emission limits in the world, namely the Swiss pollution standards.

Abstract: An improved multi-fuel heater using a porous fuel vaporizer in close proxty to an burner cup the improved heater having means to ameliorate the build up of particulate material between the cup and the vaporizer.

Abstract: A waste gas burner (10) comprises burner means (12) into which waste gas is fed through injectors (15), each leading to an open end of a conduit (17) to cause natural aspiration of primary air (20). The primary combustion takes place in a reaction zone (19) surrounded by a peripheral wall (16) which is pierced by ducts (23) so as to introduce recirculated combustion products under natural draught. Secondary air intakes (25) surround the peripheral wall (16) of the reaction zone (19) and promotes secondary burning of the recirculated gases. The reaction zone has a high temperature short duration combustion without excess air and the secondary combustion takes place at a lower temperature with a longer retention time and in the presence of excess air so as to reduce nitrogen oxide formation and ensure combustion of impurities in the waste gas.

Abstract: Flue gas is captured from an emissions stack and recirculated to a burner by an induced flue gas recirculation system comprising: a mixing assembly for mixing combustion air and recirculated flue gas into a substantially homogeneous mix; a burner assembly for mixing and combusting the combustible mix with a fuel to produce a flue gas; an injection assembly, connected to and downstream from the mixing assembly and connected to and upstream from the burner assembly, for receiving the combustible mix from the mixing assembly and injecting it with the combustible fuel into the burner assembly; a combustion chamber connected to and downstream of the burner assembly for containing the combustible mix and flue gas; an emissions stack connected to and downstream from the combustion chamber for venting the flue gas from the combustion chamber; recirculating means for recirculating a portion of the flue gas from the emissions stack to the mixing assembly; and a purge assembly connected to the recirculating means for re

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: A regenerative burner having heat storage units with combustion effluent/combustion air ducts therethrough, fuel intake means and a burner body, wherein the burner is designed to suppress NOx formation and to control flame shape and characteristic in the regenerative system during combustion. The regenerative burner may include a burner baffle, or may include a plurality of gas jets entrained in generally converging fashion for control of the flame characteristics and shape dispositive of NOx formation. The burner may provide for staged combustion, either by means of sequential fuel injection or sequential provision of combustion air, or the burner may depress NOx formation by vitiation of combustion air with products of combustion. The present regenerative burners suppress NOx formation yet preserve the remaining characteristic features of regenerative systems.

Abstract: A fuel burner assembly is provided with concentric chambers, the central chamber of which houses the fuel delivery nozzle, the annular chamber surrounding the central chamber comprising an intake and mixing chamber for receiving heated combustion air and ambient fresh air, the annular chamber being ported to pass the mixture of heated and ambient air to the central chamber to mix with the fuel delivered from the nozzle which is heated by the air mixture, the inlet ports to the annular chamber being adjustable as are the ports from the annular chamber to the central chamber, an adjustable iris baffle adjacent the upstream end of the annular chamber controls the stream of primary air delivered to the central chamber.

Abstract: To avoid high NOx emissions, the fuel is oxidized with an extremely high exhaust gas recirculation ration substantially without flames and without pulsations.

Abstract: A gasifier (17) is located at a distance (49) from an air aperture plate (35). At the outlet (42) of the gasifier there is a stationary mixing head (29) having a deflector section (31) and lateral outlets (33). Fuel is supplied coaxially through an opening (55) of the air aperture plate. A flame tube (21) surrounds the gasifier (17) and an electric heater (39) leaving an annular space (40). When the burner is started up, the electric heater (39) is switched on until the gasifier has the necessary operating temperature. Fuel is then supplied. The fuel/air mixture is ignited by an electrode (65). The flame tube (21) extends to the end of the mixing head (29), or only a little therebeyond. A flame is formed at the outlets (33) that touches the flame tube after a short travel, then emerges from it and expands. Because the flame can immediately expand, only little NO.sub.x is formed.

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: A method and apparatus for recirculating flue gas in either a vertical or a horizontal pulse combustor which is dedicated to deliberate one-stage pulse combustion. At least one combustion chamber wall defines a mixing region and a combustion chamber which is adjacent the mixing region. A fuel inlet conduit is used to supply fuel into the mixing region and an air inlet conduit is used to supply air into the mixing region and thereby form an air/fuel mixture within the mixing region. Air valves are in communication with the fuel inlet conduit and the air inlet conduit. An ignition source is positioned within with mixing region for igniting the air/fuel mixture and beginning the pulse combustion process. An exhaust system removes flue gas containing products of pulse combustion. A portion of the flue gas produced during pulse combustion is then recirculated into the mixing region, air inlet, and/or an air decoupler.

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: A burner assembly comprises a burner tube and a nozzle assembly used as a source of fuel and air for the burner tube. The burner tube is cylindrical and extends longitudinally about an axis. The burner tube includes two flame grids, each of which is located around the outside periphery of the burner tube and which supports a blue flame. A series of flame retention barriers are mounted about the periphery of the burner tube adjacent the flame grids.

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: The invention relates to the improved combustion of fuel in a combustion chamber of a stirling engine and the like by dividing combustion into primary and secondary combustion zones through the use of a diverter plate.

Abstract: An in situ thermal system is disclosed for enhanced oil recovery and the like from a subterranean formation. The system pressurizes the formation with water whereupon the entire formation is heated to relatively high temperatures in the absence of gas formation to significantly decrease the viscosity of substantially all the crude in the formation and permit recovery thereof. A down hole, fuel fired radiant tube burner of long length is provided to achieve the desired heat patterns within the formation. The burner includes three concentric, closed end tubes with the innermost tube containing a burner and spaced closely adjacent the intermediate tube. A hole pattern in the innermost and intermediate tube establishes a laminar flow of the burner's products of combustion therebetween which modifies the radiation heat flux pattern so that uniform heat is emitted from the outermost tube along its length.