Abstract: A method and apparatus for use in burners of furnaces such as those used in steam cracking. The apparatus includes a burner tube having a burner tip mounted on the downstream end of the burner tube adjacent to a first opening in the furnace, so that combustion of the fuel takes place downstream of the burner tip. At least one passageway from a second opening in the furnace ending adjacent to the upstream end of the burner tube is provided. Also provided is a means for drawing flue gas from the furnace through the passageway in response to an inspirating effect created by uncombusted fuel flowing through the burner tube. At least one heat exchange tube disposed in the passageway wherein air that is cooler than the flue gas flows through the heat exchange tube into a secondary air chamber permitting heat to be transferred from the flue gas to the air to create preheated air.

Abstract: System for reducing NOx emissions from burners of furnaces such as those used in steam cracking. The system includes a furnace having at least one burner, the at least one burner including a primary air chamber; a burner tube including a downstream end, an upstream end in fluid communication with the primary air chamber for receiving air, flue gas or mixtures thereof and fuel, a venturi portion positioned between the downstream end and the upstream end, and a burner tip mounted on the downstream end of the burner tube adjacent the first opening in the furnace for combusting the fuel downstream of the burner tip; and a fuel orifice located adjacent the upstream end of the burner tube for introducing fuel into the burner tube; a source of flue gas, said source positioned so as to enable the flue gas to achieve a temperature of less than 2000° F.

Abstract: A burner is provided which includes a plurality of burner subunits that each share a single air supply, a single fuel supply and a single control system. Each burner subunit has a plurality of air orifices and a plurality of fuel orifices of sufficient quantity and of a cross-sectional area to control a transverse heat flux profile of the burner. The burner subunits are spaced with respect to one another to control a longitudinal heat flux profile of the burner. The single air supply and said single fuel are adapted to provide an air-fuel mix that ensures the transverse and the longitudinal heat flux profiles are maintained at different fuel and air input rates. A burner of similar design using premixed air and fuel is also disclosed.

Abstract: A method and apparatus for reducing the temperature of the recirculated flue gas in a flue gas recirculation duct for burners in industrial furnaces such as those used in steam cracking.

Abstract: The present invention relates to a method and to a device intended for spontaneous combustion of a fuel comprising organic, vegetable or mineral materials, the device comprising a combustion chamber, at least one fuel injection means, at least one air inlet, hot fumes discharge means. Chamber (1) comprises a cylindrical shell (11), the discharge means comprise a pipe (6) having the same axis as the chamber and arranged inside said chamber, and fuel injection means (7) is arranged substantially tangential to said cylindrical shell so that the fuel follows a circular motion around said pipe in the chamber.

Abstract: An improved burner and a method for combusting fuel in burners used in furnaces such as those found in steam cracking.

Abstract: A burner for a thermal post-combustion device comprises a combustion nozzle, which comprises a substantially hollow-cylindrical base member (1) at least virtually closed at one end by a cover (2). Fuel gas is supplied thereto axially at a particular pressure. The fuel gas flows out radially via main discharge openings (8) of the combustion nozzle. These main discharge openings (8) are at such a radial distance from the axis of the base member (1) and exhibit such a cross-section that, at the particular pressure of the supplied fuel gas, individual flames form at the main discharge openings (8) which substantially do not overlap. While maintaining the same total burner power, in this way the individual flames remain colder than in known burners, which produce a cohesive ball of flame instead of individual flames.

Abstract: A swirl-type internal flame recirculation burner apparatus and method as used to fire asphalt plant aggregate dryers, air heaters and calcining kilns and method includes a compressed air oil atomizer assembly. The burning and swirling fuel and primary main combustion air mixture recirculates upstream along the burner axis. The secondary main combustion air may be swirled. The burner may also be fired on gas or a combination of gas and oil.

Abstract: A process for incinerating combustible materials including the steps of: delivering combustible material and inlet gases to a primary combustion chamber, the inlet gases having an oxygen content of at least 50 vol %; burning the combustible material with the oxygen of the inlet gases in the primary combustion chamber producing flue gases and solid particulates as thermal decomposition products of the burnt combustible material; passing the flue gases and particulates to a secondary combustion chamber where further combustion occurs; cooling the flue gases exiting the secondary combustion chamber; returning a portion of the cooled flue gases to at least one of the combustion chambers where the cooled gases moderate the temperature in the at least one chamber; and passing the remaining portion of cooled flue gases on to a flue gas purification system where pollutants in the flue gases and particulates are substantially converted to benign compounds or removed entirely before the flue gases are emitted into the

Abstract: A system and method for increasing reaction and reactor efficiency, including the steps of providing a reactor with a plurality of reagent introduction or injection ducts, asymmetrically positioned in a tangentially reinforcing manner at spaced apart predetermined locations; injecting at least one reagent; wherein the velocity of the injected reagent(s) is such that the ratio of the reagent velocity to the reactor width is between about 2 sec−1 to about 150 sec−1; thereby increasing reaction and reactor efficiency and reducing the byproducts produced thereby, via mixing and rotation of the reaction space.

Abstract: A system and method for increasing combustion furnace efficiency, including the steps of providing a furnace with a plurality of secondary air injection ducts, asymmetrically positioned in an tangentially reinforcing manner; injecting fuel with substoichiometric primary air through the burners; injecting secondary air through the plurality of secondary air injection ducts; wherein the velocity of the injected air is such that the ratio of the advected air velocity to the furnace width is between about 2 sec−1 to about 150 sec−1; thereby increasing combustion efficiency and reactor efficiency via mixing and rotation of the combustion space.

Abstract: A miniature combustor comprising a combustion chamber having at least one critical dimension that is sub-centimeter. Combustion is confined within the chamber by injecting a liquid fuel as a film over substantially the entire area of the chamber walls. In a preferred embodiment, a swirl or vortex generator may be included at the entrance of the chamber to cause the in-flowing oxidizing gases to swirl within the chamber. The liquid fuel may be applied as a film through one or more orifices or a porous wall material, or may be applied by spraying the fuel on a surface within the chamber. The liquid fuel may be augmented with an inert liquid such as water.

Abstract: A tangential fired boiler has a circumferential wall defining a combustion zone and a plurality of fuel inlets disposed along the circumferential wall. The plurality of fuel inlets inject fuel at non-uniform rates in order to produce localized fuel rich, oxygen poor zones and fuel lean, oxygen rich zones within the combustion zone, and to cause ambient boiler gases to be entrained into and mix with the oxygen poor zone to achieve fuel staging of the boiler.

Abstract: A method for combusting fuel in a fired heater having one or more burners, the method comprising: (a) combusting at least a portion of the fuel in the presence of an oxidizer in the burners, generating heat and producing a flue gas; and (b) recycling at least a portion of the flue gas to the burners; wherein step (a) and step (b) are conducted in a manner such that the combusting takes place in a combustion regime represented by 1 4 , 500 ≥ 7554.8 - 933.72 ⁢ x + 64.960 ⁢ x 2 + .47705 ⁢ y - .55680 ⁢ z - 1579.

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

Abstract: A catalyst composition and method for oxidizing fuels is disclosed. The catalyst composition comprises at least one compound having one of a group III, group IIA or Lanthanide element such as, for example, Aluminum, Magnesium or Cesium, and at least one compound having at least one element selected from group IA, group IVA, group VI, group VII, group VIII, group IB, group IIB, and combinations thereof, such as, for example platinum, rhodium and rhenium. A method for oxidizing an fuel, the method comprising providing a fuel and a catalyst mixture; transporting the fuel and the catalyst to the flame zone separately; mixing the fuel and the catalyst; and oxidizing the fuel. The method and catalyst mixture may be used for oxidation of any hydrocarbon based fuel. Improved results from the use of the group III, group IIA or Lanthanide group element include increased power, reduced harmful emissions, and smoother oxidation process.

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

Abstract: An ultra low NOx burner for process heating is provided which includes a fluid based flame stabilizer which provides a fuel-lean flame at an equivalence ratio in the range of phi=0.05 to phi=0.3 and fuel staging lances surrounding the flame stabilizer in circular, flat, or load shaping profiles, each lance comprising a pipe having a staging nozzle at a firing end thereof, each lance having at least one hole for staging fuel injection, and each hole having a radial divergence angle and an axial divergence angle. The at least one hole and the divergence angles provide circular, flat or load shaping flame pattern. The burner provides NOx emissions of less than 9 ppmv at near stoichiometry combustion conditions.

Abstract: In a combustion method, in a burner (12, 20), a fuel/air mixture flowing through a flow passage (13) is made to react in a first combustion stage in a catalytic reactor (15), and downstream of the catalytic reactor (15) fuel is burnt together with the exhaust gas from the catalytic reactor (15) in a second combustion stage to form a homogenous flame (17) by self-ignition.

Abstract: A tangential fired boiler has a circumferential wall defining a combustion zone and a plurality of fuel inlets disposed along the circumferential wall. The plurality of fuel inlets inject fuel at non-uniform rates in order to produce localized fuel rich, oxygen poor zones and fuel lean,-oxygen rich zones within the combustion zone, and to cause ambient boiler gases to be entrained into and mix with the oxygen poor zone to achieve fuel staging of the boiler.

Abstract: A burner for a heat generator comprises a swirl generator (1) for a combustion-air flow and means for injecting fuel for producing a main flow (6). A combustion chamber (2) is arranged downstream of the burner.

Abstract: A symmetric device for stabilization of a flame includes a primary oxidant pipe and a fuel pipe. The fuel pipe is internal to the primary oxidant pipe creating a primary oxidant conduit. A secondary oxidant pipe is internal to the fuel pipe creating a fuel conduit. A primary oxidant source supplies oxidant to the primary oxidant conduit. A fuel source supplies fuel to the fuel conduit. A secondary oxidant source supplies oxidant to the secondary oxidant pipe. The first oxidant velocity is greater than the second oxidant velocity and the fuel velocity is less than the second oxidant velocity. The primary oxidant pipe end extends past the fuel pipe forward end and the fuel pipe forward end extends past the secondary oxidant pipe end. A mismatch in velocity between fuel and oxidant generates a large scale vortex. An asymmetric embodiment is also provided.

Abstract: Combustion method and apparatus for NOx reduction are capable of easily achieving NOx reduction to an exhaust NOx value of 30 ppm or under. The combustion method is to perform in combination a first NOx reduction step for suppressing generated NOx value to 60 ppm or under (at 0% O2 in exhaust gas, dry basis) by a low NOx burner, a second NOx reduction step for recirculating exhaust gas of the low NOx burner to a burning reaction zone formed by the low NOx burner, and a third NOx reduction step for adding water or steam to the burning reaction zone.

Abstract: This invention, Centrifugal and Divided Space combustion method, need to install a cylindrical fuel pot, the first combustion chamber, the second combustion chamber and an exhaust pot. It also needs to install the upper and the lower pots outside the first combustion chamber and the fuel pot in order to have the lower and the upper air paths inside the outer pots. One or several ventilator(s) to make air-flow is tangentially connected to the upper and the lower air paths at the lower part of the upper outer pot. And several air-flow control devices should be located at the upper part of the upper air path. Thus, the invention is composed to realize the complete combustion only with the air supply into the furnace. In this case, the space in the furnace is divided into many combustive sectors by the air-flow.

Abstract: The invention relates to a burner with a burner head (1) and a gas feed pipe (2) that is located in the burner head (1) and that is surrounded by an ring channel (3) for feed of another gas. In the gas feed pipe (2) and in the ring channel (3), there are means (10, 11) for producing a swirl of the gas flowing through the gas feed pipe (2) and that flowing through the ring channel (3).

Abstract: A system for reducing pollution components from a combustion process includes at least one burner modified in such a way so as to minimize production of at least one pollution component, an over fire air system which injects secondary air above the burner, a tempering system which injects a cooling fluid into a combustion zone of the burner so that the fluid is entrained to intersect an identifiable high pollutant component producing zone, a non-catalytic reduction system which injects a reagent into flue gases produced by the burner, and a targeted chemical injection system which injects a pollutant component reducing agent into a nearby turbulent combustion zone of the burner without a destruction of the agent by high temperatures, thus enabling the agent to be widely dispersed by the nearby turbulent zone before reaching a more distal zone where more favorable conditions for pollutant component reduction by the agent prevail.

Abstract: A burner having high peak temperatures in a first turbulent zone near the entry of fuel into the combustion region is altered so as to have a peak temperature that is below the temperature at which a chemical useful to remove a pollutant would dissociate or have its activity destroyed. While this peak temperature is reduced in the first zone, the chemical is injected therein. This zone's turbulence causes the chemical to be dispersed without being destroyed during its transit to reach a second distal zone where pollutants prevail in conditions favorable for their removal by the chemical. The chemicals can be delivered by way of a powder or by being dissolved in liquid droplets. The sizes of the droplets are selected so as to enable the chemically laden droplet to survive transit through the first zone so as to reach the second distal zone intact to treat polluting components.

Abstract: The invention describes a premix burner, in which fuel and air can be mixed to form a fuel/air mixture, for forming at least one stable flame front within a downstream combustion chamber for driving a gas turbine which follows the combustion chamber, having a premix burner casing which is formed in the manner of a tube open at the upstream end, is connected in the downstream direction to the combustion chamber via a transition contour and through which air can flow, a burner lance, which is designed as an inner tube, projects into the interior of the premix burner casing on the upstream side, encloses a flow passage which is annular in cross section together with the premix burner casing, and has an inner tube wall which surrounds an inner flow passage and in which there is at least one fuel-addition unit for feeding fuel into the inner flow passage and at least one further fuel-addition unit for feeding fuel into the annular flow passage is provided in such a manner that downstream of the inner tube the fuel

Abstract: A method of effecting burning is described wherein combustible materials are introduced into a vortex having a high pressure periphery and a lower pressure center, or are caused to form such a vortex and there is provided further fluid to provide for the combustion of this material, and the mixture is ignited whilst in the vortex. A variation of this is method of effecting burning which includes the step of introducing as a burnable mixture, a mixture into a vortex of a type having an outer periphery with a higher pressure than its pressure at a center of the vortex. The methods are useful for generating heat, steam or disposal of wastes.

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

Abstract: A method and an appliance are described for supplying fuel to a premixing burner for operating a gas turbine, which premixing burner has at least one burner shell (1, 2) at least partially bounding an axially extending premixing burner space, having a premixing gas supply directed into the premixing burner space via the burner shell (1, 2), the premixing gas (6) being mixed with combustion inlet air and being ignited downstream external to the premixing burner,

Abstract: A combustion chamber includes a mixing zone and a combustion zone within which self-ignition of a fuel and air mixture can occur. Fuel and support air are injected laterally at the sidewall of the mixing zone into hot gases passing through the mixing zone. The operating range of the combustion chamber can be increased while noxious substances are reduced by injecting differently controlled fuel/support air mixture jets into different target spaces within the mixing zone.

Abstract: Methods and apparatus for combustion of a hydrocarbon fuel in a combustion chamber of a furnace or boiler are presented, the combustion normally using only air as an oxidant, part of the air entering the combustion chamber through one or more burners, and a remaining portion of air entering the combustion chamber at a plurality of locations downstream of the burners. The methods comprise injecting oxygen-enriched gas through a plurality of lances into the combustion chamber at a plurality of downstream locations, the oxygen-enriched gas injected at a velocity ranging from subsonic to supersonic, and the oxygen-enriched gas being present in an amount sufficient to provide an oxygen concentration of no more than 2% on a volume basis greater than when air is used alone as oxidant.

Abstract: Improved apparatus for burning fuel with low NOx formation are provided. An apparatus of the invention for discharging a mixture of fuel gas and air into a furnace wherein the mixture is burned and flue gases having a low NOx content are formed includes the following. A burner housing, attached to a furnace, is provided having a means for mixing a first portion of the fuel gas with a first portion of the air to form a primary fuel gas-air mixture and discharging the primary fuel gas-air mixture into a primary burning zone in the furnace from at least one discharge location surrounded by a wall which extends into the furnace. A means for mixing a second portion of the fuel with a second portion of the air to form a secondary fuel gas-air mixture is also provided whereby the secondary fuel gas-air mixture is discharged into a secondary burning zone in the furnace from at least one discharge location adjacent to an exterior side of the wall.

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

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

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

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

Abstract: The invention relates to a catalyzer for burning at least part of a fuel/oxidant mixture flowing through the catalyzer, in particular for a burner of a power plant installation. The catalyzer comprises several catalytically active channels and several catalytically inactive channels. A longitudinal section of the catalyzer is spaced apart from an inflow side in the main flow direction. In this longitudinal section turbulators are arranged in at least several catalytically active channels. In addition or alternatively, connections that enable a flow between the channels are formed in this longitudinal section between several adjoining channels.

Abstract: A device for burning a gaseous fuel/oxidant mixture, in particular for a power plant installation, includes a catalyzer/swirl generator arrangement. Part of the fuel/oxidant mixture is burned in the catalyzer/swirl generator arrangement and the catalyzer/swirl generator arrangement generates a swirl flow. The catalyzer/swirl generator arrangement includes several flow channels, of which some are constructed catalytically active and others catalytically inactive. The flow channels can be arranged distributed around a longitudinal central axis of the catalyzer/swirl generator arrangement, and can be slanted relative to the axis.

Abstract: A fuel nozzle, comprising an inlet for receiving fuel and an outlet for discharging fuel. The outlet intersects a longitudinal centerline of the nozzle and produces a skewed spray pattern. A fuel injector having a fuel nozzle outlet such that a fluid discharged from a swirler produces a crescent-shaped spray pattern in the fuel. A burner section of a gas turbine engine comprising a combustion chamber and fuel injectors. At least one of the fuel injectors produces a skewed flame pattern in the combustion chamber that overlaps with a flame pattern from an adjacent fuel injector. A method of improving stability of a flame in a burner section of a gas turbine engine in which at least one of the fuel injectors produces a skewed flame pattern in the burner section to create a fuel non-uniformity, the flame pattern also overlapping with an adjacent flame pattern.

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

Abstract: A method and apparatus for reducing the temperature of the recirculated flue gas in a flue gas recirculation duct for burners in industrial furnaces such as those used in steam cracking.

Abstract: A method and apparatus are disclosed for use in furnaces such as those used in steam cracking. The apparatus includes a burner tube having a downstream end and an upstream end for receiving fuel and flue gas, air or mixtures thereof, with a burner tip being mounted on the downstream end of the burner tube adjacent a first opening in the furnace, so that combustion of the fuel takes place downstream of the burner tip. The burner includes at least one passageway having a first end at a second opening in the furnace and a second end adjacent the upstream end of the burner tube, the passageway having a cross-sectional area and shape sufficient to permit a total FGR (flue gas recycle) ratio of greater than 10%. In addition, the burner includes a means for drawing flue gas from the furnace through the passageway in response to an inspirating effect created by uncombusted fuel flowing through the burner tube.

Abstract: An improved burner and a method for combusting fuel in burners used in furnaces, such as those used in steam cracking, are disclosed. The burner includes a burner tube having an upstream end, a downstream end and a venturi intermediate said upstream and downstream ends, the venturi including a throat portion having substantially constant internal cross-sectional dimensions such that the ratio of the length to maximum internal cross-sectional dimension of the throat portion is at least 3. A burner tip is mounted on the downstream end of the burner tube adjacent a first opening in the furnace, so that combustion of the fuel gas takes place downstream of said burner tip.

Abstract: An improved burner and a method for combusting fuel in a burner used in furnaces such as those found in steam cracking. The burner includes a burner tube having a downstream end and an upstream end, the burner tube having a venturi therein; a fuel spud located adjacent the upstream end of the burner tube, for introducing fuel gas into the burner tube; a burner tip mounted on the downstream end of the burner tube adjacent a first opening in the furnace; at least one passageway having a first end and a second end adjacent the upstream end of the burner tube; means for drawing flue gas from the furnace, through the passageway, in response to an inspirating effect of uncombusted fuel gas exiting the fuel spud, the uncombusted fuel gas flowing through the burner tube from its upstream end towards its downstream end; and means for increasing the inspirating effect of uncombusted fuel gas exiting the fuel spud.

Abstract: A method for reducing NOx emissions from a furnace having multiple burners, each burner including at least one chamber for supplying a flow of combustion air and means to adjust the flow of air to the at least one chamber. The method includes the steps of measuring a parameter correlative of combustion air flow; adjusting the flow of combustion air to the at least one chamber so that the parameter is within a predetermined tolerance; and repeating the aforementioned steps for a plurality of burners.

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

Abstract: System for reducing NOx emissions from burners of furnaces such as those used in steam cracking. The system includes a furnace having at least one burner, the at least one burner including a primary air chamber; a burner tube including a downstream end, an upstream end in fluid communication with the primary air chamber for receiving air, flue gas or mixtures thereof and fuel, a venturi portion positioned between the downstream end and the upstream end, and a burner tip mounted on the downstream end of the burner tube adjacent the first opening in the furnace for combusting the fuel downstream of the burner tip; and a fuel orifice located adjacent the upstream end of the burner tube for introducing fuel into the burner tube; a source of flue gas, said source positioned so as to enable the flue gas to achieve a temperature of less than 2000° F.

Abstract: A burner for use in furnaces such as the type employed in steam cracking.