Abstract: The disclosure is directed to a burner-containing apparatus, such as a boiler or a furnace, having reduced noxious emissions. A burner receives input air and has an exhaust for exhausting flue gases. A flue gas recirculation system is provided for recirculating a portion of the flue gases back to an input of the burner. A fogging device, which produces a fog from a fogger water supply and a fogger air supply, humidifies the recirculated flue gases.

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 combustion apparatus comprises a combustion chamber disposed about a central longitudinal axis and means to separately introduce oxidant and fuel into the combustion chamber such that when ignited, the resulting diffusion flame swirls about the central axis and exhibits characteristics of a premixed flame. The asymmetric nature of the flame components introduction allows the combustion to be conducted stably at a fuel rich or fuel lean condition and if desired, to extinguish the flame. The fuel oxidant ratio can be reduced such that nitrogen oxide emissions are reduced. Great combustion stability obtained at low equivalence ratios and elimination of possibility of flashback are achieved in the new process and due to the spinning flame, combustion is completed in very short distances.

Abstract: High velocity gas injection system wherein high velocity and low velocity gases are injected into a cavity in a defined relationship such that the low velocity gas forms a protective barrier from combustion zone damage due to the flow dynamics caused by the high velocity gas.

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: A gas burner is described having a cylindrical combustion chamber having at least two spaced apart counter-rotation stationary tangential air injectors and at least three sets of radial injection holes in between for admitting air under pressure in the combustion chamber to cause adjacent counter-rotation air turbulence regions in said combustion chamber. The combustion chamber has a closed end and an open end with a gas injector tube extending in the chamber from the closed end and disposed centrally therein. The injector tube has combustion gas injection ports at least upstream and downstream of the at least two air injectors to create a combustion mixture which is initially fuel-lean to generate a flame having a lower temperature and producing less nitrogen oxide than with conventional gas burners of this type. An air chamber is provided about at least a portion of the combustion chamber and communicates with the tangential air injectors.

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

Abstract: A gas-fired burner incorporating an air driven jet pump for mixing air, fuel, and 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. The burner achieves reduced NO.sub.x emission levels in high temperature applications which use preheated combustion air.

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 combustor includes inner and outer arrays of generally Vee-shaped, radially extending, circumferentially spaced gutters canted in a circumferential direction relative to one another to produce isolated concentric counter-rotating circumferentially directed flows downstream of the gutters. A lean premixed combustion mode is used at baseload operations. At non-baseload operations, particularly low-load operating conditions, a diffusion combustion mode is employed by direct fuel injection into air supplied to one of the isolated flow fields, preferably the radially inner flow field, to produce a stabilized, locally hotter flame, resulting in higher combustion efficiency and lower emissions than otherwise using a lean premixed combustion mode at the non-baseload operating conditions.

Abstract: A burning method promotes rapid mixing and a stable flame in a burner to reduce NO.sub.x and CO emissions and to provide a smoother, quieter operation. 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 radially into the swirling combustion air. A bluff body cone is arranged near the exit of the burner so as to be encountered by at least the swirling combustion air. An atomizer is arranged within the bluff body cone for atomizing liquid fuel when the primary fuel supply is a liquid fuel. Boost gas nozzles are arranged toroidily at the exit of the burner to supply and mix swirling boost gas for combustion with the combustion air when the gaseous fuel is the primary fuel supply, and mixer tabs are disposed around the periphery of the exit.

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: 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: An industrial gas burner is disclosed which operates at low air/fuel ratios to avoid NO.sub.x formation without carbon sooting. The burner includes a refractory block having a cylindrically stepped throat passage extending therethrough, a housing adjacent the inlet end of the refractory block and a swirl plate inbetween the block and housing. Vane passages in the swirl plate provide fluid communication between the throat passage and an annular entrainment passage in the housing. A plurality of circumferentially spaced gas jet nozzles in the entrainment passage cause jet entrainment and mixing of fuel and combustion air which is ported to the entrainment chamber. The jet streams of mixed air/fuel impinge the swirl plate whereat the mixture undergoes a further mixing because of the pressure drop and swirling therein. The swirling air/fuel mixture is thus intimately and thoroughly mixed when it exits the swirl plate as a swirling mass at the entry end of the throat passage where it is ignited.

Abstract: An air register apparatus, method, and arrangement is disclosed in which each air register includes two portions, one of which feeds combustion air to an inner, ignition zone where fuel is first ignited, the other of which feeds combustion air to an outer, supplemental zone where the main combustion takes place. These two register portions provide separate and discrete air streams having measurable characteristics which accurately reflect the characteristics of the overall flow through each register portion and which characteristics govern combustion characteristics in the associated zone. Each air stream passes through an inwardly spiralling scroll passageway having a simple upstream air valve at the entrance to the passageway for controlling the flow of air through the passageway. This upstream air valve is remote from the hostile environment of the furnace or other combustion device.

Abstract: A low pollutant emission, high efficiency cyclonic burner and cyclonic combustion process for firetube boilers and heaters in which the combustion air required for complete combustion is introduced into the cyclonic burner in stages. Fuel and primary combustion air in an amount of about 30% to about 90% of the stoichiometric requirement for complete combustion of the fuel are tangentially injected into a primary combustion zone of a combustion chamber within the burner. Secondary combustion air in an amount of about 10% to about 90% of the stoichiometric requirement for complete combustion of the fuel is introduced into a secondary combustion zone in the combustion chamber downstream of the primary combustion zone. The combustion chamber walls are cooled to maintain the combustion chamber temperature between about 1600.degree. F. and 2400.degree. F.

Abstract: A method for adjusting a burner during the start-up phase in a furnace operated with recirculated flue gas (3), the furnace is subjected to a pre-flushing period prior to start-up. The furnace is started with a constant fuel amount (5), the fresh air (2) aspirated from the outside at first being reduced by means of a control. In the beginning, the stoichiometric or near-stoichiometric air balance for combustion is provided by recirculation of the fresh air (4) in the furnace. Following ignition of the burner, an increase of fresh air (2) from the outside will take place as a function of the diminishing fresh air (4) from the furnace. The diminishing fresh air (4) recirculated from the furnace is replaced by also recirculated flue gases (3) in such a way that at the end of the start-up phase only a combustion air mixture consisting of fresh air (2) from the outside and recirculated flue gases (3) is used.

Abstract: The invention is a process for combusting a gaseous fuel in a burner to result in low NO.sub.x emissions by first feeding a gaseous fuel stream and an air stream to a premixer where the fuel and air streams are mixed to form a fuel-air mixture. The fuel and air streams are fed to the premixer at a fuel to air equivalence ratio of less than 1 (i.e., fuel-lean). Second, the fuel-air mixture is passed to a combustion chamber where the fuel is substantially combusted to produce a combustion chamber jet and flue gases. The combustion chamber jet and flue gases pass into a heating zone which may include a furnace, heater, or boiler. Third, at least two high-velocity fuel streams, optionally diluted with a nonreactive thermal ballast, are passed to the heating zone contemporaneously with the second step. The high-velocity fuel streams entrain at least a portion of the flue gases. The fuel in the high-velocity fuel streams is partially combusted prior to coming into contact with the combustion chamber jet.

Abstract: A furnace firing apparatus and method for burning low volatile fuel in which first and second burners are provided to introduce particulate, air-suspended fuel into primary and secondary combustion zones of a combustion chamber. The alignment of the second burner is adjustable and aligned so that the stream of fuel and air introduced by the second burner entrains combustion products produced by the burning of fuel in the primary combustion zone in order to ignite the fuel introduced by the second burner. Secondary air is provided by a pair of plenum chambers to support combustion of the fuel. In an alternate embodiment, an intermediate burner is provided to entrain combustion products from the combustion of fuel introduced by the first burner and whose combustion products are entrained into the fuel introduced by the second burner.

Abstract: A combustion method employing fuel-rich combustion with an upstream recirculation zone followed by a downstream plug flow zone enabling rapid heating and processing without excessive NO.sub.x generation or particulate emissions.

Abstract: A gun-type oil burner is disclosed having a motor axially aligned with a fuel pump and a blower at opposite ends. The blower draws air into the burner, the amount of which is controlled by an adjustable air gate. The blower inlet is covered by a removable, protective air scoop. Upon removal of the air scoop, an outside air boot is easily connected to the burner without burner modification. The air in the burner travels along a serpentine path which contains smooth curves and perimetrally disposed protrusions for reducing the velocity of the air flow and maintaining its static pressure. The air flows through an air tube in a helical pattern, mixes with oil and is ignited at the air tube outlet. A fuel nozzle, ignitors and a fuel supply conduit are supported as a burner sub-assembly within the tube by a spider. A preselected stop of a number of removable stops of differing sizes is located on the spider and properly positions the burner sub-assembly within the air tube.

Abstract: A device for oxidizing gaseous materials, comprising a combustion chamber, wherein the device and the combustion chamber both have a top and a bottom, the device further having a gas outlet and being adapted to operate in conjunction with means applying negative pressure to the outlet, means for introducing process gas and a source of fuel into the top of the combustion chamber, means for effecting heat exchange between oxygen-containing gas and the combustion chamber to preheat the oxygen-containing gas, means for introducing the preheated gas into the top of the combustion chamber, means for mixing the preheated gas with the process gas and fuel so that the mixture can burn in the combustion chamber to form an exhaust gas, means for permitting the gas to exit from the bottom of the combustion chamber, means for diluting the exhaust with air to form a flue gas, and means for directing the flue gas from the bottom of the combustion chamber out of the outlet of the device.

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

Abstract: In a firing installation, fresh air (6) is drawn in and mixed with a fraction of flue gases (7), which are taken from the combustion chamber (1), by means of a fan (5) which acts outside of the casing of the firing installation. The fresh air/flue gas mixture (8) thus formed flows on its way to the combustion chamber (1) through a first heat exchanger (2a) whose caloric preparation is accomplished by the flue gases (7) fed in. In the combustion chamber (1) itself, this mixture flows through a heat exchanger (2) placed there. Before the mixture (9) thus preheated is fed as combustion air to a burner (4), it undergoes a further mixing with flue gases via a number of jet injectors (3), which further increases the temperature of this combustion air (10), with an optimized flue gas fraction.

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: A sulfur recovery process wherein a minor fraction of a hydrogen sulfide-containing gas is precombusted with oxygen in an externally cooled combustion zone while extracting the major fraction of the heat released in the substantially complete combustion of hydrogen sulfide to sulfur dioxide in that zone, the gas is further cooled and is then passed to a Claus reaction furnace together with the major fraction of the gas, enabling using oxygen for a substantial productivity increase within the temperature and flow rate limitations of a Claus plant without need for a temperature moderator introduced into the precombustor.

Abstract: Ammonia-containing sour gas is combusted at high flame temperature with at least 90 percent purity oxygen in an externally cooled combustor, the ammonia-free product is cooled, then, in conjunction with additional acid gas which does not contain ammonia, is passed to a Claus furnace wherein less than one-third of the hydrogen sulfide is combusted with oxygen enriched air enabling boosting sulfur recovery in a Claus plant without detrimental effects on catalyst life, furnace refractories and pressure drops.

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: In a premixing burner, which consists of two hollow partial conical bodies (1, 2), which are positioned on one another and have a cone inclination increasing in the direction of flow, the fuel feed takes place via central fuel nozzle (3) and/or via a plurality of fuel nozzles (17), which are placed along the inflow of the combustion air (15) into the interior (14) of the burner. The combustion air (15) itself is a mixture of fresh air and exhaust gas. The fresh air is led up via a first flow funnel (23a, 23b ) and exhaust gas recirculation takes place via a second flow funnel (22a, 22b). These two gases mix with one another before flowing tangentially into the interior (14). An optimum, homogenous fuel concentration over the cross-section arises in the region of the return flow zone (6).

Abstract: In a combustion installation, a mixture of fresh air (D) and exhaust gas (C) is fed to the burner (A) via a mixing/conveying device (EFG). There is provided in the combustion installation a heat exchanger (M), which undertakes the thermal conditioning of the mixture (H) before the latter is fed into the burner (A).

Abstract: A method for reducing the flame temperature of an oxy-fuel burner, such a burner comprising a central oxygen nozzle at least one fuel nozzle radially spaced from the central oxygen nozzle, and at least one peripheral oxygen nozzle at greater radial distance from the central oxygen nozzle than the fuel nozzle, all nozzles being at least substantially parallel, a casing surrounding the nozzles and whose forward end lies in a plane at right angles to the longitudinal axis of the burner, and whose rear portion defines an oxygen chamber, and means for the supply of oxygen-containing gas and fuel, respectively, to the nozzles. The peripheral oxygen nozzle is in the form of a Laval nozzle or, if it is an annular nozzle, is of the same cross-sectional variation as the Laval nozzle throughout its entire length.

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 order to provide an expansive central recirculating gas zone (40) in a combustor (10), and in a manner wherein the combustion chamber (20) is of compact volume, a stored energy combustor (10) comprises a vessel (12) having narrow, spaced-apart inlet and outlet ends (14, 16) interconnected by a wall (18) defining a relatively wise combustion chamber (20). The combustion chamber (20) is generally annular and a wall (18) defining the combustion chamber (20) includes an upstream wall region (18a) and a downstream wall region (18c) interconnected by a generally annular side wall region (18b). The inlet end (14) and outlet end (16) are generally tubular extensions of the vessel (12) leading to and from the combustion chamber (20) and oxidant is swirled in the tubular extension (14) leading to the combustion chamber (20) and directed in a swirling annulus into the combustion chamber (20) outwardly of a fuel injector (28).

Abstract: A method and apparatus for reducing NO.sub.x emissions from premix burners by recirculating flue gas. Flue gas is drawn from the furnace through a pipe or pipes by the aspirating effect of fuel gas and combustion air passing through a venturi portion of a burner tube. The flue gas mixes with combustion air in a primary air chamber prior to combustion to dilute the concentration of O.sub.2 in the combustion air, which lowers flame temperature and thereby reduces NO.sub.x emissions. The flue gas recirculating system may be retrofitted into existing premix burners or may be incorporated in new low NO.sub.x burners.

Abstract: Furnace gas is aspirated through furnace gas conduits (44) to the low pressure throats (42) of the Venturi conduits (41) that move high oxygen content gas to the combustion chamber (28) of the aspirating burner (20). Fuel is injected through fuel conduit (46) to the combustion chamber (28) to mix with the gases and form the flame in the combustion chamber which is emitted at high velocity from the burner into the furnace.

Abstract: A fluid mixing device has a chamber with a fluid inlet and an opposite fluid outlet. The device causes a flow of a first fluid wholly occupying the inlet to separate from the chamber wall upstream of the outlet. The distance between the flow separation and the outlet is sufficiently long in relation to the width of the chamber for the separated flow to reattach itself asymmetrically to the chamber wall upstream of the outlet and to exit the chamber through the outlet asymmetrically. A reverse flow of the first fluid at the reattachment and/or a flow of a second fluid induced through the outlet thereby swirls in the chamber between the flow separation and the reattachment and induces precession of the separated/reattached flow. This precession enhances mixing of the flow with the second fluid from the exterior of the chamber.

Abstract: A spray burn floating combustible material burner apparatus is disclosed herein used to remove a floating layer of combustible material, such as oil, from a body of water. The apparatus includes a support frame attached to a buoyancy system, an air nozzle, an air nozzle adjustment means, drop-catching means, a deflection plate, a stabilization plate, and an ignition source. The air nozzle is attached to the air nozzle adjustment means, which adjusts the vertical position of the air nozzle with respect to the surface of the floating layer, and to an adjustible supply of compressed air which, during operation, vertically lifts and atomized the floating layer into droplets in the apparatus' combustion region. The ignition source located in the combustion region destroys the atomized droplets by combustion. The drop-catching means is positioned above the combustible material and prevents any ignited droplets from falling into the surrounding layer of combustible material.

Abstract: A method and apparatus for recovering hydrocarbons in a which a first toroidal vortex of fuel and a combustion supporting gas is created with its center adjacent the axis of an elongated combustor; a second toroidal vortex of combustion supporting gas is generated between the first toroidal vortex; the fuel is burned in the presence of the combustion supporting gas to produce a fuel gas at the downstream end of the combustor; water is introduced into the flue gas adjacent the downstream end of the combustion to produce a mixture of flue gas and water; a major portion of the water is vaporized in a vaporizor to produce a mixture of flue gas and steam; and the mixture of flue gas and steam is injected into a hydrocarbon bearing formation.

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: In a firing plant which is operated with fossil fuels, the exhaust gases (A) from the combustion space (22) are cooled in a heat exchanger (X). A part of these cooled exhaust gases (A') are mixed with fresh air (L) and are conducted by means of a fan (D) in the direction of the burner (Z). This exhaust gas/fresh air mixture forms the combustion air (15) for the burner (Z). Before the introduction of this combustion air (15) into the burner (Z), it is again heated in the heat exchanger (X'). The combustion air (15) preheated in this way ensures complete evaporation of a liquid fuel (12) and acts against the high flame temperature peaks in the combustion space (22) immediately after the burner (Z), which are responsible for the formation of NO.sub.x. The burner (Z) can be operated with liquid and/or gaseous fuel.

Abstract: An apparatus and method for ultra-low pollutant emission combustion of fossil fuel wherein an elongated cyclonic primary combustion chamber has a cross-sectional area about 4 to about 30 percent that of an elongated cyclonic secondary combustion chamber and a volume about 1 to about 20 percent the combined primary and secondary combustion chamber volume. A first fuel portion of about 1 percent to about 20 percent of the total fuel and primary combustion air in an amount selected from about 40 to about 90 percent and about 140 percent to about 230 percent of the stoichiometric requirement for complete combustion of the first fuel portion is introduced into the primary combustion chamber. A second fuel portion of about 80 to about 99 percent of the total fuel is introduced into the secondary combustion chamber with secondary combustion air in an amount of about 150 percent to about 260 percent of the stoichiometric requirement for complete combustion of the fuel.

Abstract: The burner of the present invention has a throat section which is in communication with a fire tube located downstream from the throat section. Nozzle means are provided for introducing a fuel in the throat section in a downstream direction toward the fire tube. Very importantly, means are provided for forming a swirling combustion air stream substantially along the side walls of the throat and fire tube thereby reducing the static pressure along the axis of the burner. Also very importantly, means are provided for introducing a gas stream to the throat and downstream of the nozzle means in a swirling direction opposite to that of the swirling combustion air stream.

Abstract: A burner for directly flaming steel making materials to accomplish reduction without oxidation, wherein the burner comprises a plurality of combusion air outlets spaced circumferentially of the inner wall of a tubular burner tile, and fuel gas outlets disposed centrally of the burner tile, and wherein the combustion air outlets and fuel gas outlets are formed and disposed with specified jetting angles and distances to produce burning without oxidation.

Abstract: A method for combusting wet waste wherein heat released by the combustion of combustibles from dry waste is recirculated by operation of high velocity oxidant in order to dry wet waste.

Abstract: A system is provided for reducing the amount of nitrogen oxides produced by conventional gas-fired boilers, water heaters, or other heat transfer devices by diluting the fuel gas with an inert gas. The system includes a mixing unit or region for diluting fuel gas with an inert gas before the fuel gas is supplied to a burner assembly of a combustion device. Flue gas from the combustion chamber of the combustion device may be used to dilute the fuel gas.

Abstract: A burner for directly flaming steel making materials to accomplish reduction without oxidation, wherein the burner comprises a plurality of combustion air outlets spaced circumferentially of the inner wall of a tubular burner tile, and fuel gas outlets disposed centrally of the burner tile, and wherein the combustion air outlets and fuel gas outlets are formed and disposed with specified jetting angles and distances to produce buring without oxidation.

Abstract: The smokeless ignitor of the present invention prevents visible emissions upon cold or hot start-up of coal-fired or oil-fired utility boilers. The smokeless ignitor satisfies flame stability and combustion requirements by establishing a flame with 15-30% mass recirculation rate, a recirculation zone length of 0.75-1.5 effective throat diameters, a spray SMD of less than 120 microns and a STU value of .+-.50% or less.

Abstract: A burner for directly flaming steel making materials to accomplish reduction without oxidation, wherein the burner comprises a plurality of combustion air outlets spaced circumferentially of the inner wall of a tubular burner tile, and fuel gas outlets disposed centrally of the burner tile, and wherein the combustion air outlets and fuel gas outlets are formed and disposed with specified jetting angles and distances to produce burning without oxidation.

Abstract: A burner for directly flaming steel making materials to accomplish reduction without oxidation, wherein the burner comprises a plurality of combustion air outlets spaced circumferentially of the inner wall of a tubular burner tile, and fuel gas outlets disposed centrally of the burner tile, and wherein the combustion air outlets and fuel gas outlets are formed and disposed with specified jetting angles and distances to produce burning without oxidation.