Abstract: A combustion chamber 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. An annular insert is disposed in the combustion area and generally surrounds the flame of the burner. The annular insert defines a secondary gas introduction zone for introducing secondary gases into the combustion area so that the recycled 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. The opening is disposed tangentially to the insert inner surface to direct gases in rotational motion to define a film of gases adjacent the inner surface of the combustion chamber. The body of the chamber can include an outer shell and an inner cylindrical liner. The outer shell has a generally horizontal inwardly extending support shelf.

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

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

Abstract: A spin vane for burners and over fire air ports in a furnace comprise a sheet-like vane element having a base and an extension extending perpendicularly off the base on the low pressure side of the vane element. The extension reduces the formation and propagation of vortices on the low pressure side of the vane, increasing flow efficiency and reducing pressure loss across the spin vanes.

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

Abstract: A method is disclosed for reducing NOx pollutants in the combustion of hydrocarbon fuels in a two stage burner. A first stage of combustion is established and maintained passing a stream of combustion air and first stage products of combustion down a centerline of the burner to a second stage downstream therefrom. This second stage is established by arranging an array of fuel tips around the first stage burner, each fuel tip having a fuel jet with a nominal trajectory angled toward the burner centerline and an inert gas jet placed between the burner and the fuel jet which is angled to cross the trajectory of the fuel jet. Fuel is injected into the second stage of the burner through the fuel jet and the inert gas, e.g. steam, is injected through the inert gas jet such that it influences the trajectory of the fuel to a modified fuel trajectory which is moved away from the centerline of the burner.

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

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

Abstract: The invention relates to a water heating apparatus and method to passively recirculate flue gas in order to reduce NO.sub.x emissions formed during combustion. The apparatus uses a high efficiency burner, a submergible, pressurized, combustion chamber having multiple external heating surfaces, and a flue collector that collects and passively recirculates a portion of the flue gases back into the burner air intake while exhausting the rest. The multiple external heating surfaces are installed within a closed tank and are submerged in water under pressure during use.

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

Abstract: In a combustion chamber with at least one premixing burner (110) which is fastened by means of its burner outlet (118) to a front plate (54) bounding the combustion space of the combustion chamber (60), the gaseous fuel is introduced via gas inlet flow openings (117) arranged around a burner axis (100). The fuel is mixed with the combustion air prior to ignition. The fuel concentration at the burner outlet (118) is lower at the outer edge of the flow field generated by the premixing burner (110) than it is in the inner part of the flow field. The temperature of the combustion gases at the outer edge of the bonnet-shaped reverse-flow zone (121), which gases impinge on the combustion chamber wall (63), is lower than the average temperature of the combustion gases in the bonnet-shaped reverse-flow zone (121).

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: In the process and installation for decontaminating a liquid effluent contaminated by at least one organic substance, a gaseous combustible is burned in a reactor to produce a flame containing hydroxyl free radicals OH.degree. and oxygen O.sub.2 and that flame is centered on the geometrical axis of the reactor. A helical flow of liquid effluent is produced on the inner cylindrical wall of the reactor to cause a direct contact between the hydroxyl free radicals and the organic substance contaminating the liquid effluent. By means of the hydroxyl free radicals, the organic substance is oxidized in liquid phase. The high temperature of the flame enables completion of the oxidation of the organic substance, in liquid phase, by means of the oxygen O.sub.2 present in the flame. At the outlet of the reactor, the liquid and gaseous products are separated; the liquid product is collected while the gaseous product is evacuated.

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 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: A fuel burning heater comprises a housing 1 provided with a fluid passage 13 defined in a wall thereof, and a burner 2 accommodated in an inside space of the housing 1 to heat fluid filled in the fluid passage 13. A fuel supply device 3 supplies fuel into the burner 2. An air supply device 4, including an air supply pipe 41, supplies air into the burner 2. An exhaust gas circulating device 5 circulates exhaust gas, produced in the burner 2 by combustion of air-fuel mixture, to the air supply pipe 41. A control unit 7 increases an amount of the exhaust gas circulated by the exhaust gas circulating device 5 when an amount of fuel supplied by the fuel supply device 3 is reduced.

Abstract: For reducing pollutant generation in a tangentially fired furnace, a method and apparatus for modification of a main air-fuel compartment. An extender dish for mounting on the discharge face of the compartment has a wide projection to extend across the discharge face half portion closer to the axis of the fireball in the furnace firing chamber and a narrow projection to extend across the discharge face half portion further from the fireball axis. Preferably a flow restricting plate is also provided to extend across a part of the discharge face portion closer to the axis of the fireball. These air restricting means cause a portion of the combustion air from the main air-fuel compartment discharge face to be directed outside the fireball therein reducing oxygen concentration and flame temperature thereby lowering pollutant generation.

Abstract: In the case of a heat generator which essentially consists of a premix burner (100) and a flame tube (1), the hot gases (10) from the combustion in the premix burner (100) are fed into the flame tube (1), and there undergo staged post-combustion. This post-combustion takes place by means of a first post-combustion stage (11) and a second post-combustion stage (12). The air/fuel mixture (11a, 12a) is provided for each post-combustion stage (11, 12) in individual mixers (200, 300). These mixers are arranged axially with respect to the flame tube (1) and work in such a way that injection of the corresponding mixture (11a, 12a) makes it possible to obtain different combustion zones which extend in a staged sequence over the flame tube (1). By virtue of this staged post-combustion mode NO.sub.x emissions can be reduced by a factor of 5 compared to conventional techniques.

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

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

Abstract: A burner 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: In a firing installation which is designed to minimize the pollutant emissions during the use of both a liquid and a gaseous fuel, an annular chamber (12) is arranged downstream of a first combustion stage (1) on the head side of a second combustion stage (2) arranged downstream. The first combustion stage (1) is operated as a lean stage with a burner (100), while the second combustion stage (2) is operated as a near-stiochiometric stage. The wall of the annular chamber (12) has a number of openings (13) for the inflow of a mixture (14) of recycled flue gas (4) and fuel (15). The combustion air (115) for the burner (100) is likewise a mixture (6) of air (3) and recycled flue gas (4). The hot gases from this first combustion stage (1) are moderated before entering the second combustion stage (2), self-igniting combustion taking place in this second combustion stage (2) starting from the annular chamber (12).

Abstract: Methods for the incineration of waste gas containing oxygen are disclosed which, in one aspect, have a combustion chamber with a high intensity, stable burner jet projecting therein and a backmixing zone in which are mixed burner fuel and waste gasses flowing into the chamber via a waste gas flow line. As desired additional fuel, e.g. fuel such as methane added to vitiated air, may be introduced into the chamber. Preferably, the heat content of the supplemental fuel is adjusted to control temperature in the combustion chamber while a stable combustion zone is provided. In one aspect flue gas from the chamber flows to a heat recovery apparatus to recover heat value of the flue gas.

Abstract: A burning method provides a versatile burner by promoting rapid mixing and a stable flame to reduce NO.sub.x and CO emissions over a wide operating range. The burner includes a primary fuel supply, a combustion air supply arranged to supply combustion air at low pressure, and a swirler for swirling the combustion air. When the primary fuel supply is gaseous fuel, the gaseous fuel is introduced axially into the swirling combustion air. Secondary gas nozzles are arranged at the exit of the burner to supply and mix boost gas for combustion with the combustion air when the gaseous fuel is the primary fuel supply. An atomizer is arranged for atomizing liquid fuel when the primary fuel supply is a liquid fuel.

Abstract: Process is described for reducing emissions of nitrogen oxides and carbon monoxide from fuel gas fired boilers by using a computer to closely control the flow rate of combustion air and by installing a duct to allow flue gas to recirculate into the air intake of the boiler. In most cases strict emission standards can be met without making any other mechanical modifications to the boiler. A computer controller maps burner characteristics and controls both a variable speed drive and the damper on the combustion air fan, and a damper on recirculated flue gas to meet emission requirements over the various firing rates while maintaining a stable flame free of pulsations. In some burners a simple cone structure placed in the burner provides additional flame stability.

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 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: Combustion air is supplied being divided into inner and outer cylinders of a main burner body, and liquid fuel is injected and burnt by a liquid fuel injection nozzle provided in the inner cylinder, wherein a tip end injection hole of the nozzle faces outside of the nozzle through a fore end opening of the inner cylinder. An annular flame piloting baffle plate for the inner cylinder is provided in front of the injection hole of the tip end opening of the inner cylinder, a swirler is provided inside of a tip end portion of the outer cylinder, and an annular flame piloting baffle plate is provided at a tip end opening portion of a cylindrical space formed between the outer and inner cylinders. Due to the foregoing construction, flames of the burner for burning liquid fuel are stabilized and an amount of generated NOx gas is reduced.

Abstract: A burner structure and a method of operating a burner to reduce the pollutant emissions produced thereby are disclosed. Air and gas are premixed in a manner such that a substantially homogeneous mixture containing excess combustion air results. The velocity of the substantially homogeneous mixture is increased as it passes through the burner causing the "residence time" associated with the formation of the flame to be decreased, i.e., the combustion gases are in the reaction zone of the flame for a significantly shorter period of time, reducing the production of NO.sub.x. In order to prevent the flame from "lifting-off" the burner because of the high velocity of the substantially homogeneous air/gas mixture, flame stabilizing devices and/or a burner structure which provides flame stabilization are utilized resulting in the production of a high heat flux and low pollutant emissions.

Abstract: A low NO.sub.x burner includes a primary air and fuel discharge assembly which, in turn, includes a burner plate having a plurality of slots from which fuel gas jets and combustion air are discharged. The slots are arranged such that the width of the recirculation zones between adjacent slots substantially varies between the central region of the burner plate and its perimeter. With this construction, the local ignition patterns vary such that local oscillations of flame front occur at different frequencies so that vibrations are greatly dampened and resonance problems in the furnace minimized or eliminated. In applications where high excess air is not desirable, such as boiler applications, the burner is modified by providing a secondary fuel and flue gas injection assembly to form a two stage burner. In the preferred embodiment, the secondary injection assembly includes a plurality of discrete fuel and flue gas injection tubes arranged around the primary air and fuel gas discharge assembly.

Abstract: A burner assembly is provided for combining oxygen and fuel to produce a flame. The burner assembly includes a burner block formed to include a flame chamber having inlet and outlet openings, a bypass structure for conducting oxygen outside of the flame chamber to the outlet opening of the flame chamber and structure for discharging fuel into the flame chamber formed in the burner block.

Abstract: A multivortex device is provided comprising a series of adjacent plates with specially designed grooves and perforations which, when mounted transversely of a uniform fluid flow in a duct, results in the formation of numerous small adjacent flow vortices either all rotating in the same direction (co-vortices) or adjacent vortices rotating in opposite direction (countervortices). The fluid at the peripheries of adjacent co-vortices move in opposite directions and friction converts their rotational kinetic energy into turbulence within a few vortex diameters downstream from the multivortex device. The fluid at the peripheries of adjacent counter-rotating vortices move in the same direction, such that they roll upon one another substantially without friction and persist for many vortex diameters downstream from the multivortex device. The adjacent plates of the multivortex device can be provided with additional grooves and passageways which allow a second and/or third fluid to be introduced within each vortex.

Abstract: The present invention provides an air-oxy-fuel method and apparatus in which fuel is burned in first and second stages of combustion having a fuel-rich and fuel-lean stoichiometry, respectively, to reduce NO.sub.x, emissions. The fuel is burned in the first stage of combustion in oxygen. The combustion of the fuel is completed in the second stage of combustion in the presence of air. Mixing of fuel and oxygen is effected by forming fuel and oxygen jets in close proximity to one another. Air is then swirled around the fuel and oxygen jets at a swirl ratio of no less than about 0.6 so that combustion products of the fast stage of combustion recirculate to obtain stable combustion of a very fuel-rich flame which is characterized by increased flame luminosity. The use of air allows for a lesser degree of swirling than had a single oxidant been used in both the fast and second stages of combustion because a greater mass of air is supplied than oxygen.

Abstract: The present invention is concerned with a method of operating an oil evaporation burner for heating boilers which, for NOX reduction, are operated with an exhaust gas return from the combustion chamber of the heating boiler into the burner.In oil evaporation burners of the afore-described type the exhaust gas return during the start-up phase presents certain difficulties inasuch as the burner frequently goes off during the start-up phase. To overcome such difficulties the flow of exhaust gas as returned during the start-up phase is pneumatically discontinued by the formation of blocking curtains from air as supplied.

Abstract: A combustion method wherein high velocity fuel is injected into a cavity recessed from a furnace zone for flow into the furnace zone, low velocity oxidant fluid is injected into the cavity for coaxial flow with the fuel, and the resulting combusting fuel and oxygen has imparted to it an angular component by operation of swirling oxygen flow and/or outwardly angled fuel flow, enabling control of the high velocity flame length.

Abstract: A low calorific gas is burned without the need of mixing or burning it with a high calorific gas. The method includes introducing either combustion air or low calorific gas into the mixing chamber, introducing the remainder into the mixing chamber through the perforated nozzles such that it is injected in the radial direction at a high speed from the holes to effect the mixing of the two in the mixing chamber, and injecting the mixed gas into the combustion chamber through the nozzles of the refractory baffle. The stable combustion of a low calorific gas alone by the aid of combustion air without the need of diffusing it into the atmosphere or burning it together with an expensive high calorific gas or oxygen-enriched combustion air is thereby effected, which greatly contributes to energy saving and environmental protection.

Abstract: The invention provides a method and apparatus for creating a stable combustion flame from natural gas and an oxygen containing gas which is useful for the pyrometallurgical treatment of finely divided materials such as metal ores. In particular, natural gas and the oxygen containing gas are injected in a manner which forms recirculation zones between the natural gas and oxygen containing gas thereby maintaining the stability of the combustion flame. The apparatus of the invention encourages the formation of the recirculation zones by using a bluff body orifice plate to provide a dead space between the injections of the oxygen containing gas and natural gas. Additional gas injection is used downstream in the combustor to create turbulence and further stabilize the combustion flame.

Abstract: A kinetic dissociator is formed by a primary combustion chamber and a secondary combustion chamber. The primary and secondary combustion chambers are connected by at least one flow stabilization tube. A source of high temperature, high velocity gas is provided by at least one high speed combustion jet axially aligned with the flow stabilization tube such that the jet gas mixes with a process gas passes through the tube and impinges against a conically shaped wall forming a portion of the secondary combustion chamber.

Abstract: A firing installation includes a combustion space fed by premixing burners having combustion air inlet slots along the length of the burner bodies that create a tangentially directed inflow of combustion air. Fresh air guides are positioned along the inlet slots upstream to guide fresh air into the slots, and include an end plate having a plurality of perforations that act as air injection nozzles. Movement of fresh air through the nozzles creates a vacuum that draws combustion air from the combustion space into the inlet slots where it mixes with the fresh air to form a combustion gas mixture.

Abstract: A burner flame stabilizer which circumferentially stages the air to form circumferentially-spaced fuel rich and fuel lean zones for lowering of NO.sub.x is described. A circumferential solid fuel stager is described, which operates with a fuel stabilizer to provide increased dwell time for coal particles volatilization in a recirculation zone established by the flame stabilizer. Various embodiments are described.

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: 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: There is disclosed an oxy/fuel burner with a low volume fuel stream. The burner projects a stream of fuel from a fuel orifice and projects an annular stream of oxygen around the stream of fuel from an annular oxygen orifice such that the oxygen velocity to gas velocity ratio is between 1/1 and 3/1, providing a flame whose hottest point is about 5 inches from the fuel orifice.

Abstract: A method of low-NOx combustion and a burner device for effecting the same, in which a primary fuel is injected in a direction from the periphery of stream of a combustion air towards that same combustion air, effecting a first combustion, so as to create a generally cylindrical primary flame covering the combustion air, whereby a secondary fuel injected towards the combustion air is shielded or intercepted by such primary flame from the combustion air, while causing NOx in the primary flame to be reduced by the secondary fuel, after which, a second combustion is effected by bringing the secondary fuel to contact with a portion of the combustion air penetrating through the primary flame, at a downstream side. This arrangement permits more positive decrease of NOx density in an exhaust gas.

Abstract: A heating system for heating a heat sink via a heat transfer medium. The invention includes a vortex chamber having opposite first and second inwardly curved end walls, a combustion chamber fluidly communicating with the vortex chamber, fuel-air supply means fluidly communicating with the combustion chamber for injecting fuel-air mixture into the combustion chamber. Ignition means are provided in the combustion chamber for igniting the fuel-air mixture. A fuel ionizing chamber is disposed in the vortex chamber fluidly communicating with the fuel-air supply means for ionizing fuel entering the fuel-air supply means, and heat transfer medium containing means are provided for holding the heat transfer medium in thermal contact with the vortex chamber.

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: 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: In a combustor including a premixing type combustion burner which has an atomizer for ejecting a liquid fuel together with combustion air to atomize the liquid fuel, the atomizer is comprised of an inner shell to an inner peripheral surface of which the liquid fuel is supplied, an outer shell defining a passage for the combustion air running substantially straightly between the outer shell itself and an outer peripheral surface of the inner shell, and a swirling-flow guide plate for swirling the combustion air passed into the inner shell, while directing it in a downstream direction. The combustor further includes a resistor abruptly decreased in sectional area downstream and provided substantially downstream of the center of the swirling flow and in the vicinity of an outlet of the premixing type combustion burner for providing a resistance to a premixture ejected from the premixing type combustion burner.