Abstract: A premixing burner is disclosed for operating a combustion chamber with a liquid and/or gaseous fuel, with a swirl generator for a combustion inflow air stream for forming a swirl flow, and with injection of fuel into the swirl flow. The swirl generator is adjacent to the combustion chamber indirectly via a mixing zone or directly, in each case via a burner outlet, a cross-sectional widening at the burner outlet being provided which, is discontinuous in the flow direction of the swirl flow and through which the swirl flow bursts open so as to form a backflow zone. A contour locally narrowing the flow cross section of the swirl generator or of the mixing zone in the flow direction can be provided upstream of the burner outlet.

Abstract: Combustion head and method for combusting liquid and/or gaseous fuel having a flame front distanced downstream from the combustion head, in which fuel is discharged in a downstream direction radially outward at an angle at the end of the combustion head located downstream toward at least several guide devices and into a combustion chamber.

Abstract: A method for a staging operation at start up of a burner for a gas turbine engine combustor is provided. The method will stabilize the combustion of a lean-rich partially premised low emission burner for a gas turbine combustor at all engine load conditions. The method includes, adding fuel mixed with air to the pilot combustor, igniting the mixture utilizing an igniter provided at an upstream end of the pilot combustor for initiating a lean flame inside the pilot combustor and for providing the flow of the radicals and heat, imparting a swirl of fuel and air at the outside at the exit of the pilot combustor at the upstream end of the combustion room for creating and sustaining the main lean flame and gradually adding a swirl of air and fuel for establishing a full load stage to at least one channel.

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

Abstract: A method and a device for combusting gaseous fuel which contains hydrogen or consists of hydrogen, includes a burner which provides a swirl generator (1) into which liquid fuel is feedable centrally along a burner axis (A), forming a liquid fuel column which is conically formed and which is enveloped by, and mixed through with, a rotating combustion air flow which flows tangentially into the swirl generator (1). The gaseous fuel is fed inside the swirl generator (1) largely axially and/or coaxially to the burner axis (A), forming a fuel flow with a largely spatially defined flow pattern (9) which is maintained inside the burner and bursts open in the region of the burner outlet.

Abstract: A fuel nozzle tip for use with a combustor and a method of assembling the fuel nozzle tip are provided. The fuel nozzle tip includes a fuel tube and an air collar coupled to the fuel tube. The fuel tube includes a first plurality of circumferentially-spaced fuel openings and a second plurality of circumferentially-spaced fuel openings. The fuel tube is configured to channel fuel into a mixing zone defined within the combustor. The air collar includes a plurality of circumferentially-spaced air openings configured to discharge air into the mixing zone. At least one of the plurality of air openings is oriented to facilitate generating a swirl number of greater than 0.6 within the mixing zone.

Abstract: A premix burner is provided, with a swirl generator and a downstream mixer tube for combusting gaseous and liquid fuel which during entry of combustion air is introduced into the burner interior space of the swirl generator and/or is introduced into the burner interior of the swirl generator on a burner axis, and also with a fuel lance which is arranged on the burner axis. The premix burner, in the transition section from the swirl generator to the mixer tube, includes at least one additional feed for introducing gaseous and/or liquid premix fuel from the wall region into the burner interior space of the mixer tube.

Abstract: A furnace, firing pattern and method of operating a heater that employs a combination of hearth burners and wall burners for the cracking of hydrocarbons is described. The firing pattern leads to improvements in the uniformity of the coil metal temperatures and vertical heat flux profiles over the firebox elevation. The hearth burners operate with a stoichiometric excess of air while the wall burners operate with less than the stoichiometric amount of air.

Abstract: A device for combusting fuel which contains or consists of hydrogen, is described, with a burner provided with a swirl generator and also a feeder for feeding fuel and a feeder for feeding combustion air into the swirl generator. A first feeder, for feeding liquid fuel along a burner axis, and a second feeder for feeding liquid fuel or gaseous fuel along air inlet slots which are tangentially delimited by the swirl generator, with a transition section connected downstream to the swirl generator, and with a mixer tube connected downstream to the transition section and with a changeable flow cross-sectional transition leads into a combustion chamber are provided. Along the transition section, a third feeder for feeding fuel which contains or consists of hydrogen, and also a fourth feeder for the selective feed of fuel which contains or consists of hydrogen, or of the gaseous fuel are also provided.

Abstract: A means capable of supplying exhaust gas sufficiently imitating exhaust gas from actual diesel engines is provided. A PM generating apparatus has a constitution in which combustion air supplied to the space between a chassis and an outer casing via an air inlet is introduced into the space between the outer casing and an inner casing via through-holes of the outer casing, and a fuel injected by an fuel-injection means into the space between the chassis and the outer casing is introduced into the space between the outer casing and the inner casing via the through-holes of the outer casing, wherein the fuel is combusted to generate PM.

Abstract: A method of introducing oxygen into a boiler system for combustion with a prepared fuel in a furnace combustion chamber comprises providing a plurality of swirl-inducing elements to the air stream delivery lines, and a plurality of oxygen delivery jets adjacent the intake region and substantially surrounding the air stream delivery lines; igniting the fuel gas to create a flame; and delivering a stream of oxygen through the jets tangentially to the flame envelope to substantially shape and stabilize a swirling flow field for the flame, the oxygen concentration in the flame envelope gradually increasing towards an outer periphery of the flame envelope. A boiler system for using the method can be a new system or a retrofit to an existing system. The method and system provide advantages in reduced environmental impact and increased efficiency while addressing the safety factors involved in introducing oxygen to boiler systems.

Abstract: A combustion head comprising: a pipe, having a central axis of symmetry, suitable for conveying a flow of comburent air in a combustion chamber, and a plurality of gas tubes spaced out along a circumference. Each gas tube has a first portion, having an axis of symmetry parallel to the axis, and a second portion, placed in series with respect to the first portion. The second portion in inclined at an angle with respect to the axis.

Abstract: A combustion system includes a combustion zone comprising a burner for converting a fuel, under fuel rich conditions, to a flue gas; an intermediate staged air zone downstream from the combustion zone for supplying intermediate staged air to the flue gas and producing fuel lean conditions; a reburn zone downstream from the intermediate staged air zone for receiving the flue gas; and an inlet downstream from the combustion zone for supplying a mixture of air and a reduction reagent to the flue gas, wherein the reduction reagent is configured to reduce an amount of a pollutant species in the flue gas.

Abstract: An apparatus and process is provided for combining fuel and combustion air to produce a mixture. The mixture is burned in a combustion chamber to produce a flame.

Abstract: A single-ended, internally recuperated, radiant tube annulus system in which at least part of the heat recovery takes place within the furnace to which the system is attached and in which the oxidant and/or fuel are preheated not only by heat transfer from the exhaust gases, but also directly from the combustion process. The system includes a plurality of concentric radiant tubular members arranged in a manner providing an outer annular region in which the combustion process is carried out, an inner tubular member through which exhaust gases are exhausted from the system, and intermediate annular regions between the inner tubular member and the outer annular region through which preheated oxidant is provided to the outer annular region for the combustion process. In accordance with one embodiment of this invention, the internal recuperator is used as a fuel reformer.

Abstract: A method for operating a premixing burner is provided. The premixing burner includes a premixing zone. An air mass flow and fuel may be injected into the premixing zone, and a potential hot gas backflow area may form. A fluid containing no fuel is injected downstream from the fuel injection into the premixing zone in order that a hot gas backflow area does not form. A premixing burner including a premixing zone is also provided.

Abstract: The invention relates to processes for the combustion of liquid fuels, including a means of using an oxygenated gas in a combustion zone, applicable to steam boilers, which produces a longer, more uniform and cooler oxygen flame than a conventional oxygen flame. According to the invention, the liquid fuel is injected into the combustion zone in atomized form, the fuel being atomized by bringing a stream of fuel into contact with a stream of atomizing fluid, and: prior to its atomization, the liquid fuel has a viscosity of at least 30×10?6 m2/s, the stream of fuel is brought into contact with the stream of atomizing fluid only in the combustion zone, and oxygenated gas is injected into the combustion zone in stages.

Abstract: Burners in prior art exhibit combustion instabilities in certain ranges. The operating range of burners is restricted by said instabilities. In an inventive burner, the combustible has a concentration distribution, whereby the concentration of the combustible reduces in a radial direction from the interior to the exterior.

Abstract: A burner includes a first oxidant conduit to transmit a first stream of an oxidant; a solid fuel conduit having an outtake and surrounding the first oxidant conduit, thereby forming a first annulus to transmit a mixture of a transport gas and particles of a solid fuel; a second oxidant conduit surrounding the solid fuel conduit, thereby forming a second annulus to transmit a second stream of the oxidant or an other oxidant; and means for segregating the mixture proximate the outtake into a lean fraction stream and a dense fraction stream. The first stream of the oxidant exiting the first oxidant conduit combines during combustion with the lean fraction stream, thereby forming an inner combustion zone adjacent the outtake, and the second stream of the oxidant, or the other oxidant, exiting the second oxidant conduit combines during combustion with the dense fraction stream, thereby forming an outer combustion zone.

Abstract: A low NOx burner and method wherein (a) combustion air flows through the interior of the burner in a manner effective for drawing an amount of inert flue gas diluent from the fired heating system into the combustion air stream, preferably via one or more induction channels provided through the burner wall, and/or (b) air or an inert gas is discharged into the induction channel(s) in a manner effective for delivering flue gas into the combustion air stream.

Abstract: The low emission combustor includes a combustor housing defining a combustion chamber having a plurality of combustion zones. A liner sleeve is disposed in the combustion housing with a gap formed between the liner sleeve and the combustor housing. A secondary nozzle is disposed along a centerline of the combustion chamber and configured to inject a first fluid comprising air, at least one diluent, fuel, or combinations thereof to a downstream side of a first combustion zone among the plurality of combustion zones. A plurality of primary fuel nozzles is disposed proximate to an upstream side of the combustion chamber and located around the secondary nozzle and configured to inject a second fluid comprising air and fuel to an upstream side of the first combustion zone. The combustor also includes a plurality of tertiary coanda nozzles. Each tertiary coanda nozzle is coupled to a respective dilution hole.

Abstract: In a procedure for regulating a combustion process in an installation while air is being supplied, material is converted by the combustion process, with at least one flame being formed, and the state variables (s(t)) describing the state of the system in the installation are determined using at least one observation device that images the flame, as well as other sensors, and are evaluated in a computer, whereupon any appropriate actions (ai) that may be needed are selected in order to control adjusting devices for the supply of material and/or air, wherein during setpoint regulation to achieve setpoints (s0) of the state variables and/or stability of the combustion process a changeover is occasionally made from setpoint control to disturbance control.

Abstract: A noise generator system is provided with each noise generator being pivotally mounted to a mounting surface associated with the air intake of a turbineless jet engine. Each noise generator is positioned so as to convert a laminar or transitional air stream into a turbulent air stream such that a turbulent air-fuel mixture is realized in the combustion section of the engine to achieve more efficient operation.

Abstract: The present method and apparatus for producing a supersonic jet stream introduce an oxidizer in such a manner as to create a vortex, which is then restricted. Fuel is introduced into a reduced pressure eye of the vortex, forming a stratified composite stream of gases with unmixed oxidizer surrounding an inner mixture of fuel and oxidizer. This stratified composite stream is passed down a tube that exhausts to a low pressure environment. The combined fuel and oxidizer in the stratified stream is ignited to provide a high-velocity stream of combustion products. The outer layer of unmixed oxidizer in the vortex shields the tube and reduces or eliminates the need for additional cooling.

Abstract: A method for the efficient conversion of heavy oil to distillates using sequential hydrocracking in the presence of both supported and colloidal catalyst immediately followed by a high temperature-short residence time thermal treatment. The hydrocracker reaction products or a heavy oil and hydrogen donor diluent may be advantageously heated by direct contact with high velocity combustion products.

Abstract: The present invention is a method of combustion of a solid fuel stream with oxygen. The present invention includes introducing a first stream, comprising a first portion of substantially pure oxygen, into a first conduit. The present invention includes introducing a second stream, comprising a solid fuel stream and a conveying media, into a second conduit, wherein the second conduit is concentric with, and surrounding, the first conduit. The present invention includes introducing a third stream, comprising a second portion of substantially pure oxygen, into a third conduit, wherein the third conduit is concentric with, and surrounding, the first conduit and the second conduit. The present invention includes igniting the first stream, the second stream, and the third stream as they exit the first conduit, the second conduit and the third conduit, in such a way as to create a flame.

Abstract: A burner fires into a radiant tube to provide a downstream flow of combustion products within the radiant tube. Staged fuel is injected upstream into the radiant tube. A recirculation conduit inside the radiant tube receives the staged fuel along with combustion products that are inspirated into the recirculation conduit by the staged fuel. The recirculation conduit has an outlet for discharging a mixture of the inspirated combustion products and staged fuel into the downstream flow of combustion products.

Abstract: A combustor is proposed which is compact and eliminates generation of NOx and unburned combustible and is capable of stable combustion.

Abstract: A burner assembly for lean, low NOx combustion may include a gaseous fuel manifold, counter-swirl vanes, and a converging nozzle with bluff body flame anchors. A cooling air tube optionally extends from the air inlet to the nozzle.

Abstract: An animal and vegetable oils combustor, wherein primary air is introduced into a burner tile in the form of straight-ahead air flow moving straight ahead along the axial direction of the burner tile and secondary air is introduced in the form of swirl air flow moving along the inner surface of the side wall of the burner tile, whereby perfect combustion is liable to occur since a centrifugal force acts on liquid-drop fuel by swirl air flow to diffuse the fuel in the radial direction and the liquid-drop fuel does not take such a route as to be adhered to the inner wall even if char is included in the liquid drop fuel since the fuel is jetted after the grain size thereof is adjusted to small one beforehand.

Abstract: A glycerin burning system having a specialized atomizing burner capable of combusting a continuous feed of crude or pure glycerin. The burner includes a two-fluid mixing nozzle. The nozzle has an internal distributor which mixes two fluid feed streams as the fluids are expelled through an orifice. The distributor has channels which cause the air to swirl before mixing with the glycerin. An impingement pin is provided outside the orifice to diffuse the mixture and reduce combustion air speed. To improve performance, the burner's air feed line is subjected to combustion chamber to preheat the air passing through the feed line before the air is mixed with the glycerin.

Abstract: A burner assembly has a burner head and a deflector plate extending radially therefrom and across a firetube housing for supporting the burner assembly therein. The deflector plate has a plurality of angled vanes for re-directing secondary combustion air flowing through the housing. Secondary air is deflected away from a nozzle tip at the burner head to minimize lifting of the flame by the deflector plate or by a low pressure ring formed around the nozzle tip above the deflector plate for creating an area of low pressure. Preferably, a combination of the deflector plate and low pressure ring provides a stable flame positioned at the nozzle tip under low-fire and high-fire conditions enabling use of a pilotless ignition and flame sensing system which is consistent under low and high fire conditions. More preferably, the deflector plate supports the igniter and optionally a heat return tube for heat tracing of the freeze-prone burner assembly components.

Abstract: A low NOx burner system is disclosed that reduces the emission of CO and HC during cold furnace startups, minimizes NOx formation with preheated air, and provides a flat stable flame due to burner design improvements including three stage combustion. The burner system is designed to operate in either a low or high temperature mode by controlling the amount of combustion air provided to stage 1 and stage 2 combustion. The burner system is designed to heat the interior of a furnace for high-temperature combustion/furnace processes, such as aluminum melting and steel processes. The burner system can also be used for low temperature processes at temperatures below the auto-ignition temperature of the fuel and still produce very low CO, HC and NOx emissions.

Abstract: Heating provided by a burner that combusts hydrocarbon fuel can be provided at a sequence of different heat transfer rates by adjusting the total oxygen concentration of oxidant streams fed to the burner. A burner with which the method can be practiced is also disclosed.

Abstract: A combustion apparatus comprising: a device for mixing a fuel with an oxidant; a combustion chamber in which combustion of the fuel/oxidant mix takes place; a pre-chamber located between the device and the combustion chamber; and means for supplying a gas to the pre-chamber so as to form a film of gas on the interior surface of the pre-chamber so as to prevent a combustion flame from the combustion chamber attaching itself to this interior surface damaging the pre-chamber, the supply of gas to the pre-chamber being such that where the gas first reaches the interior surface of the pre-chamber it forms a substantially continuous film of gas over this interior surface.

Abstract: A method and an apparatus are provided for the combustion of gaseous fuel containing hydrogen or consisting of hydrogen, with a burner which provides a swirl generator, into which liquid fuel is fed centrally along a burner axis, at the same time forming a conically shaped liquid fuel column which is surrounded by a rotating combustion air stream which flows tangentially into the swirl generator and into which, additionally, a gaseous and/or liquid fuel is injected so as to form a fuel/air swirl flow which is transferred downstream of the swirl generator, along a transitional portion, into a mixing zone following the transitional portion downstream and which is ignited and burnt in a combustion chamber following downstream, at the same time forming a backflow zone.

Abstract: The invention relates to heat engineering and can be used for designing and reconstructing furnaces for industrial boilers. More advantageously the inventive furnace can be used for burning coarsely dispersed broken combustibles, coal and schist. The invective swirling-type furnace operating method consists in returning the controllable amount of a coal-ash mixture from an ash catcher located behind a combustion to the internal surface thereof. Said swirling-type furnace comprises a combustion chamber provided with a sloping bottom which is formed by slops of lower parts of the walls thereof, a bottom-blowing device arranged under the sloping bottom mouth and an inclined burner which is used for supplying a fuel-air mixture and is fixed to the combustion chamber wall. The furnace is provided with the ash catcher located behind the combustion chamber and a recirculation ash channel, whose one end communicates with the ash catcher and the other with the combustion chamber internal space.

Abstract: A combustor comprises in flow series a burner, a transition piece and a combustion chamber being of larger diameter than the transition piece, the combustion chamber being connected to the transition piece via a dome portion. In the dome portion are located air injection openings. A method of operating the combustor comprises the stop of introducing air from the dome portion by means of air jets.

Abstract: A low emissions burner includes a diffusion burner surrounded by an annular array of premix burners. The diffusion burner operates at maximum swirl air flow and at a low constant fuel rate to reduce NOx emissions. The diffusion burner provides a stable swirling diffusion flame. An annular array of premix burners surrounds the diffusion burner and provides a non-swirling premix flame about the diffusion flame to advantageously provide a higher heat content about the periphery of the burner flame to facilitate industrial drying processes using the burner. The diffusion burner flame maintains the premixed flame stabilized. Water injection nozzles are provided each of the premix and diffusion burners.

Abstract: A burner cone has protrusions that facilitate turbulence of combustion gases. Such cones can advantageously be utilized in thermal oxidizers that receive syn gases from pyrolyzing municipal or other wastes. Preferred cones have a frustoconical shape and numerous protrusions and associated openings. Use of such cones in thermal oxidizers can significantly increase the efficiency of oxidizing syn gases produced by pyrolyzing municipal and other wastes.

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

Abstract: An improved burner and a method for combusting fuel used in furnaces such as those found in steam cracking. The burner includes a burner tube having a downstream end and an upstream end, a burner tip adjacent a first opening in the furnace, so that combustion of the fuel takes place at the burner tip, a lighting chamber adjacent to the first opening in the furnace, and a removable lighting chamber plug having a shape effective to substantially fill the lighting chamber when positioned within the lighting chamber.

Abstract: A combustion system equipped with one or more carbonaceous fuel burning combustors (e.g., slagging Cyclone combustor) and adapted to minimize nitrogen oxide (NOx) formation during staged combustion operation by selective introduction of oxygen through at least one of the combustors to create a hot sub-stoichiometric combustion zone by reducing the diluent effect of nitrogen and other inert gases present in the oxidizer/air. A method of operating the combustion system of the invention with reduced NOx emissions is also disclosed.

Abstract: A waste oil combustion apparatus can use various kinds of waste oils and burn the same efficiently, and permits effective utilization of the thermal energy resulting from the combustion thereof. The apparatus includes a bottomed cylindrical combustion furnace, a waste oil supply unit for supplying waste oil into the furnace, an auxiliary-fuel supply unit for supplying auxiliary fuel for burning the waste oil in the furnace, an ignition burner for heating the furnace inside and the waste oil and auxiliary fuel to ignite the fuels, an air supply unit for supplying air to the furnace, and a controller for controlling each of the igniting burner, waste oil supply unit, auxiliary-fuel supply unit and air supply unit to act at a predetermined time and operate for a predetermined time. The waste oil is spirally swirled inside the furnace under the action of air from the air supply unit.

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 4,500?7554.8?933.72x+64.960x2+0.47705y?0.55680z1579.22,500; W wherein w represents a mole fraction of oxygen. in the oxidizer, x represents a recycle ratio of the flue as measured in moles of flue gas/mole of oxidizer; wherein y represents a temperature of the. flue gas in Fahrenheit recycled to the burners; and wherein. z represents a heating. value of the fuel in Btu/scf LHV.

Abstract: The present invention is directed to a process for the clean and convenient combustion of high viscosity liquid fuels, such as glycerol, as well as an apparatus useful for carrying such processes. In certain embodiments, the invention provides a process for glycerol combustion comprising providing a combustion apparatus with a glycerol combustion chamber that facilitates reflective heating, pre-heating the glycerol combustion chamber, atomizing the reduced viscosity glycerol, and combining the atomized glycerol with air in the glycerol combustion chamber to thereby completely combust the glycerol. In one embodiment, such as when using a pressure-atomizing nozzle, the inventive method may further comprise treating the glycerol to reduce the glycerol viscosity.

Abstract: A furnace, firing pattern and method of operating a heater that employs a combination of hearth burners and wall burners for the cracking of hydrocarbons is described. The firing pattern leads to improvements in the uniformity of the coil metal temperatures and vertical heat flux profiles over the firebox elevation. The hearth burners operate with a stoichiometric excess of air while the wall burners operate with less than the stoichiometric amount of air.

Abstract: A fuel injector and a combustor including a fuel injector that enables a combustor to burn a lean fuel/oxider gas mixture while providing low emissions of oxides of nitrogen (NOx), and a method of combustion. The fuel injector includes three fuel/oxider flow path channels. The first channel includes a flow balancing insert and provides a relatively straight flow. The second channel includes at least one angled vane that imparts a swirl to the flow. The third channel is a central tube, the first channel annularly surrounding the third channel, the second channel annularly surrounding the first channel.

Abstract: A method and a device for combusting gaseous fuel which contains hydrogen or consists of hydrogen, includes a burner which provides a swirl generator (1) into which liquid fuel is feedable centrally along a burner axis (A), forming a liquid fuel column which is conically formed and which is enveloped by, and mixed through with, a rotating combustion air flow which flows tangentially into the swirl generator (1). The gaseous fuel is fed inside the swirl generator (1) largely axially and/or coaxially to the burner axis (A), forming a fuel flow with a largely spatially defined flow pattern (9) which is maintained inside the burner and bursts open in the region of the burner outlet.

Abstract: The invention relates to a pre-mix burner for burning a low-calorie combustion gas, said burner comprising an air duct which extends along an axis of the burner and can be used to supply combustion air. A swirling device is arranged in the air duct and is used to apply a swirling motion to the combustion air. An injection device for the low-calorie combustion gas is provided downstream of the swirling device. The injection device comprises inlets for the combustion gas, such that the formation of wake regions in the air channel is prevented. The invention also relates to a method for burning a low-calorie combustion gas, according to which a swirling motion is applied to the combustion air, low-calorie combustion gas is injected into the swirled combustion air and intensively mixed therewith, and the mixture is then burned.