Abstract: A process for the preparation of a natural liquid fuel and, more particularly, a process that allows a high sulfur natural fuel to be converted into energy by combustion with a substantial reduction in sulfur oxide emissions.

Abstract: A method of reducing the NO.sub.x --emissions during combustion of nitrogen-containing fuels via burner units each including a primary burner and being arranged in a wall of a closed combustion chamber; fuel and air for combustion are supplied to the burner flame in stages as partial flows via delivery means which are separate from one another.

Abstract: A ribbon gas burner for use in a baking oven has a row of gas apertures disposed between two rows of air apertures through which air is forced under pressure. The streams of air issuing from the two rows of air apertures are inclined inwardly towards the gas stream, thereby lengthening the ribbon flame produced by the burner and improving the uniformity of heating within the band oven.

Abstract: Sintered particles of pulverulant glass and cellulating agent are coated with a parting agent and introduced into a fluidizing vessel. Gas is passed upwardly through the fluidizing vessel at a velocity sufficient to form a fluidized bed of these sintered particles within the fluidizing vessel. The gas and fluidized bed of sintered particles are heated within the fluidizing vessel to a cellulation temperature of the sintered particles to cause the sintered particles within the fluidized bed to form discrete cellular glass nodules of uniform size. The cellular glass nodules formed within the fluidized bed of sintered particles, having a density less than the density of the sintered particles, migrate to the top of the fluidized bed to float on the top surface of the fluidized bed. The discrete cellular glass nodules floating on the top surface of the fluidized bed are withdrawn from the fluidizing vessel.

Abstract: An atomizer and atomizing process of a post-mixed liquid fuel fired burner comprising angular direction of atomizing fluid into liquid fuel as it passes along a fuel passage length of increasing surface area causing the formation of a fuel film on the fuel passage surface area with the increasing thinning of the fuel film as it passes across the increasing surface area, resulting in a shearing action at the fuel passage end and the formation of an atomized spray.

Abstract: A method and apparatus for burning fuel in an annular-nozzle burner wherein a compact flame is generated by inhibiting the dispersion of fuel particles and concentrating the fuel particles in a primary combustion area having a high rate of radiant heat transfer between the fuel particles by maintaining a sufficiently high velocity of the fuel particles and causing them to undergo esentially linear flow in a direction substantially parallel to the axis of the burner.

Abstract: A device for improved combustion of gaseous fuel and air includes a tubular housing and has a combustion chamber disposed about the tubular housing. A first conduit extends from one end of the tubular housing for the passage of air therethrough. A second conduit extends coaxially through the first conduit and tubular housing and has a circular baffle cooperative therewith so as to retard the passage of air. A circular opening in the second end of the tubular housing has an annular baffle disposed therein to assist in retarding flow of air. A series of curvilinear fins are disposed in a spiral configuration between the circular baffle and the annular baffle so as to effect a swirling motion of air passing therethrough. An end cap is attached to the end of the second conduit with a circular baffle at one end of the end cap, an annular baffle at the other end and fins disposed therebetween. Gaseous fuel passes through the second conduit and the end cap.

Abstract: A method of and an apparatus for burning liquid and/or solid fuels, especially coal or the like, in pulverized form, the latter either in dry condition or mixed with a carrier liquid such as water and/or oil to form an emulsion being introduced together with the fuel into a combustion chamber to create a spray cone which opens approximately conically, said spray cone being bounded by an external, optionally rotating flow of air. In order to form minute fuel particles immediately downstream of the fuel inlet, the latter is constituted by a central port which is defined by a continuous knife edge. Furthermore, an approximately radially directed air inlet port is associated with said central port on the side remote from the combustion chamber.

Abstract: A process and apparatus for the nitric oxide-free reaction of liquid and gaseous fuels with heat in heat generators in a plurality of stages. The reaction is carried out in four successive stages, permitting the combustion of a portion of the fuel with a portion of the combustion air in a cooled annular chamber with a stoichiometric or overstoichiometric ratio. The remaining amount of fuel is mixed in a mixing unit connected downstream. The resulting mixture is catalytically reacted to fission or fuel gas with downstream cooling of the fission gas in a heat exchanger. The fission gas so formed is burned in one part of the cooled annular chamber of the second stage. On mixing of the burned combustion gas with the remainder of the fission gas in the catalyst, downstream cooling of the slightly overstoichiometric flue gas so formed is carried out in a heat exchanger.

Abstract: This invention relates to a flame retention burner apparatus and method of using same which can be mounted in various heat exchange apparatus and operable to efficiently and effectively achieve the diffusion and atomization of air and fuel particles for a high efficiency burning process. The flame retention burner apparatus includes a combustion head assembly having a (1) a main combustion chamber housing; (2) an inlet fuel and air diffuser assembly to initially cause agitation of fuel and air being admitted thereto; (3) a retention plate and cylinder assembly mounted within the inlet fuel and air diffuser assembly to achieve further agitation of the air particles; and (4) an air and fuel diffuser assembly operable to diffuse the inlet air particles in a new and novel manner and also to inject a liquid fuel when in that particular fuel type usage mode.

Abstract: The invention relates to a method of measuring dry substance in the flue gas in liquor recovery units in mills for the manufacture of papermaking pulp in order thereby to render it possible to control the operation of the unit. According to the invention, this is carried out in that the radiation emission caused at the combustion of fuel particles in the hearth of the unit above the fuel supply level is detected optically, and that the signals are used for indication and/or control of the operation of the unit.

Abstract: Disclosed is a catalytic combustor and systems for the boilerless stoichiometric production of a working fluid such as steam from a burn-mixture comprised of a carbonaceous fuel and a diluent. In a preferred burn-mixture, the diluent includes a first portion taken from an emulsion of the fuel and water mixed in a thermally self-extinguishing mass ratio, and a second portion taken in an amount from combustion products of a mixture previously combusted to heat the resulting burn-mixture so it combusts in the presence of a catalyst at an adiabatic flame temperature between upper and lower stability limits of the catalyst. Production of the steam is by a controlled substantially stoichiometric process utilizing a combustor to provide steam over a wide range of heat release rates, temperatures and pressures for steam flooding an oil bearing formation.

Abstract: A method and flare burner apparatus for flaring inert vitiated waste gases in an efficient stable manner are provided. The apparatus is comprised of a first tubular member for discharging waste gases having an inlet end and a discharge end and a second tubular member positioned around at least the discharge end portion of the first tubular member whereby a discharge space is provided between the first and second tubular members around and adjacent the discharge end of the first tubular member. Burner means are disposed within the discharge space for discharging and igniting fuel gas therein and fuel gas conduit means are sealingly connected to the burner means for connecting the burner means to a source of fuel gas. Air conduit means are sealingly connected to the discharge space for connecting such space to a source of combustion air.

Abstract: Methods and apparatus for combusting fuel-air mixtures while inhibiting the formation of nitrogen oxides are provided. The fuel is discharged from one or more nozzles disposed within a housing, air is caused to flow into the housing whereby it mixes with the fuel and the resulting fuel-air mixture is ignited and combusted. The nozzle or nozzles each include one or more ignition orifices for discharging a first portion of fuel in an ignition zone, one or more primary combustion orifices for discharging a second portion of fuel in a primary combustion zone containing excess air and one or more secondary combustion orifices arranged for discharging the remaining portion of fuel in the form of high velocity jets shielded by slower moving fuel within and downstream of the primary combustion zone whereby the fuel is burned in a secondary combustion zone substantially isolated from direct contact with incoming air by the primary combustion zone.

Abstract: A process and apparatus for spheridizing irregularly shaped minute particles, and the spheres produced thereby, in which a thin carbonaceous coating is applied to the particles in a unique manner, and in a preferred embodiment the particles are then advanced through successive fluidizing beds. The first bed has an inert atmosphere and is maintained at an elevated temperature sufficiently high to allow surface tension to shape the particles into spherical form while in a fluidized condition in the first bed. The spherical particles are then advanced through successive additional beds where they are cooled to an intermediate temperature sufficient to solidify the particles, are subjected to an oxidizing atmosphere which completely removes the coating, and are then further cooled while being maintained in a fluidized condition. The inert gaseous atmosphere within the first bed is continuously withdrawn and recycled through the system.

Abstract: Metal beverage closures of increased strength may be produced by a reform process which requires the initial production of a non-standard shell having a reduced countersink radius and reduced panel height. The shell is reformed, preferably in the conversion process, to industry standard dimensions, with the reduced countersink radius being maintained. To provide adequate material in the curl portion of the closure for seaming, the initial shell is provided with a reduced chuckwall diameter which is then reformed to industry standard dimensions.

Abstract: A portable gas-fired forced-draft heater has a burner assembly mounted in a tube coupled to the intake port of a motor-driven blower. The burner operates in a stream of high velocity air which flows past the burner to the blower. The burner includes shrouds which cooperate with a fuel and air mixing nozzle to enable fuel to be burned efficiently and reliably over a wide range of fuel flow rates to the burner. A flame stabilization surface is spaced appropriately from the nozzle to enable reliable ignition of the fuel-air mixture. A controlled portion of the warm gases passing through the blower is routed to a receptacle for a fuel container to maintain pressure in the container as the preferably liquefied gas fuel is consumed during operation of the heater.

Abstract: Methods and apparatus for combusting fuel-air mixtures while inhibiting the formation of nitrogen oxides are provided. The fuel is discharged from one or more nozzles disposed within a housing, air is caused to flow into the housing whereby it mixes with the fuel and the resulting fuel-air mixture is ignited and combusted. The nozzle or nozzles each include one or more ignition orifices for discharging a first portion of fuel in an ignition zone, one or more primary combustion orifices for discharging a second portion of fuel in a primary combustion zone containing excess air and one or more secondary combustion orifices arranged for discharging the remaining portion of fuel in the form of high velocity jets shielded by slower moving fuel within the downstream of the primary combustion zone whereby the fuel is burned in a secondary combustion zone substantially isolated from direct contact with incoming air by the primary combustion zone.

Abstract: A burner for the operation of premixing burners, with gaseous fuels or vaporized fuels for the production in a mixer pipe of a homogeneous mixture comprising the fuel, the quantity of combustion air required for the complete combustion of the fuel and additional cooling gas as needed for combustion between 1,100.degree. and 1,700.degree. C. This mixture flows to a burner head with a widening cross-section and a burner plate at the wide end where it is burnt at a central main flame bore arranged at the burner plate and several surrounding support flame bores. The flames then pass through a converging burner mouth and a downstream flame guard which protects the flames against the entrance of air or flue gas from the environment, against cooling and against heating until the completion of combustion. The burner mouth and the flame guard are coated by a non-catalytic material.

Abstract: A burner for the operation of premixing burners, with gaseous fuels or vaporized fuels for the production in a mixer pipe of a homogeneous mixture comprising the fuel, the quantity of combustion air required for the complete combustion of the fuel and additional cooling gas as needed for combustion between 1,100.degree. and 1,700.degree. C. This mixture flows to a burner head with a widening cross-section and a burner plate at the wide end where it is burnt at a central main flame bore arranged at the burner plate and several surrounding support flame bores. The flames then pass through a converging burner mouth and a downstream flame guard which protects the flames against the entrance of air or flue gas from the environment, against cooling and against heating until the completion of combustion. The burner mouth and the flame guard are coated by a non-catalytic material.

Abstract: The clean combustion of a combustible material is facilely carried out by (i) in situ generating a dispersing first stream of hot combustion gases by establishing a first downstream axially extending, axially symmetrical helical flowstream of combustion-supporting gases in a first combustion reaction zone and by introduction and combustion of a combustible fluid feedstream therein, (ii) serially directly contacting and intimately admixing the material cleanly combustible hereby with said first stream of hot combustion gases at a zone of reduced pressure thereof defining the inlet end of a second combustion reaction zone and whereat and downstream thereof said first stream of hot combustion gases is also in the configuration of an axially symmetrical helical flowstream, (iii) the amounts of said combustion-supporting gases and said combustible fluid being such as to effect essentially instantaneous dispersion and entrainment of fine particles of said cleanly combustible material at and downstream of said point

Abstract: The present invention relates to a combustion method for reducing the emission of nitrogen oxides. More particularly, the quick mixing of the air and fuel in the early stage of combustion is suppressed by setting the direction of fuel injection at an angle to the direction of the air stream axis and a position of a burner, in a preferable range resulting in the consequent effective use of a combustion exhaust gas, thereby minimizing the emission of nitrogen oxides to a great extent.

Abstract: To minimize NO.sub.x emissions in an intermediate size industrial boiler furnace having two vertically spaced rows of burners, each upper burner has a central fuel nozzle and a main air opening adjacent to the nozzle and communicating with a wind box associated with the furnace. In addition, each upper burner has a plurality of air delivery ports through the wall surrounding said upper burner, such air delivery ports also communicating with the wind box. The air delivery ports can be of different sizes and shapes and can be at different angles with respect to the vertical plane of the wall through which the air delivery ports extend. Control of the air through the main air opening adjacent to the nozzle of each upper burner is achieved by one or more shiftable registers or dampers which operate to close the air flow from the wind box to the air opening.

Abstract: A method and burner tip for suppressing the production of oxides of nitrogen when burning a fuel in a combustion chamber containing a flame zone are described. The burner tip comprises at least one port for introducing fuel into the combustion zone and at least one port for introducing a control gas into the combustion zone, where both the fuel and control gas are introduced substantially perpendicular to the direction of introduction of combustion gas into the combustion zone. The ports are laterally spaced apart from each other. The control gas is used for controlled localized quenching of the flame zone and/or for controlled atomization of the fuel in the case of a liquid fuel to reduce the emissions of nitrogen oxides (NOx). By proper selection of the size and location of the fuel and control gas ports, and the quantity and velocity of the fuel and control gas introduced into the combustion zone, a stable flame with minimal emission of oxides of nitrogen can be obtained.

Abstract: A method comprising injecting a primary fuel and air into a furnace to burn the fuel and form a first-stage combustion zone, the air being supplied at a rate in excess of the stoichiometric rate required for the combustion of the fuel, and injecting a secondary fuel into the furnace around or downstream of the first-stage zone at a rate approximately equal to the stoichiometric rate required for the consumption of the excess oxygen resulting from the combustion in the first-stage zone the fuel being diluted with the surrounding combustion gas and to form a second-stage combustion zone around or downstream of the first-stage zone.

Abstract: A rotary burner has fuel discharge nozzles arranged exclusively in the high velocity zone of combustion air flow. The resulting annular flame pattern has a central region adjacent to the burner hub which is essentially combustion free.

Abstract: Nitrogen oxide emissions from burning a gas containing essentially no nitrogen such as natural gas are reduced by burning the gas simultaneously with an alcohol such as methanol.

Abstract: A pair of burner tubes are arranged in concentric relationship. Fuel and air in a rich fuel-air ratio is provided to the central burner tube, and fuel and air in a lean fuel-air ratio is provided to the outer burner tube. The rich combination of fuel and air is partially burned at a temperature of about 2,500.degree. F. while the lean combination of fuel and air is burned at a temperature of less than 2,800.degree. F., and the flames from the burner tubes are mixed at the ends of the burner tubes to form a final flame envelope and to finish the combustion of the rich mixture. Exhaust gas is directed about the burner tubes, and combustion supply air is circulated about and preheated by the exhaust gas conduits and the outer burner tube. The separate combustion of the rich and lean fuel-air mixtures at relatively low temperatures and the subsequent mixing of the flames from the burner tubes results in low NOx emissions and results in high luminosity of the final flame envelope.

Abstract: In a gas turbine engine of the type wherein the fuel is injected through a pray injection nozzle into a combustion chamber, the improvement is a method and apparatus for modifying the characteristics of the fuel spray from the fuel injection nozzle so that fuels of higher aromatic content can be efficiently used in the engine. An electrode is disposed within the combustion chamber to provide a high strength electrostatic field in the vicinity of the injection nozzle so that the fuel spray from the nozzle becomes charged as it leaves the nozzle. The strength of the electric field is adjusted to provide a spray characteristic which produces optimum engine performance as determined by measuring an operating parameter of the engine such as the temperature of the gases exiting from the combustion chamber.

Abstract: A method an apparatus for combustion with a minimum of NOx emission in various industrial furnaces and boilers. By injecting air for combustion into a furnace through the burner tile or air baffle in the deviated flow pattern asymmetrical with respect to the burner tile or baffle axis, the quick mixing of the air and fuel in early stages of combustion is suppressed to provide for a relatively gentle combustion and allow the burnt gas self-circulation to take place effectively, thereby minimizing the emission of nitrogen oxides.

Abstract: This disclosure is directed to an oxy-hydrogen torch (10) comprised of a nozzle plate (16) captured between first and second outer members (12 and 14). Each outer member has a plenum (18) which open towards, and is separated by, the plate (16). The nozzle plate (16) has a plurality of spaced grooves (32--32) in one major surface (34) which are arranged in an interleaved relationship with the spaced grooves (36--36) on the opposite surface (38). The grooves (32 and 36) extend from an edge of the plate (16) to the respective plenums (18--18) in the outer members (12 and 14). Oxygen is directed into one plenum (18) and hydrogen urged into the other plenum. The gases pass through the respective grooves (32 and 36) to the surface (46) of the torch (10) for surface mixing and ignition.

Abstract: A burner for soaking pit furnaces produces essentially complete combustion of gas and air mixed in the burner. The burner includes a generally ring-shaped outer housing and a tubular inner ring spaced inside the outer housing to form a hollow annular interior chamber between the inner ring and the outer housing. The outer housing and the inner ring extend above the floor of the furnace. A narrow annular burner opening at the top of the burner is spaced above the floor of the soaking pit furnace. A gas supply pipe in the chamber directs the flow of gaseous fuel under low pressure toward the burner opening.

Abstract: The present invention resides in a dual fueled burner gun providing reduced production of oxides of nitrogen. The gun operates in a gaseous fueled mode when it is charged with a gaseous fuel or in a liquid fueled mode when it is charged with a liquid fuel. The gun may also operate in a gaseous/liquid fueled mode in which it is charged with both the gaseous and liquid fuels.

Abstract: A burner for soaking pit furnaces produces essentially complete combustion of the gas and air mixed in the burner. The burner includes a tubular inner wall structure and an outer housing spaced from the inner wall to form a hollow interior between the inner wall and the housing. The inner wall terminates adjacent a surrounding portion of the housing to form a narrow opening from the hollow interior which extends around the periphery of the inner wall structure. A gas supply pipe located in the hollow interior surrounds the inner wall structure and directs the flow of gas under pressure toward the narrow peripheral opening. In one embodiment, the inner wall forms an air supply pipe and air is forced under pressure through the air supply pipe and past the narrow opening. Gas flowing through the narrow opening surrounds and is drawn into air flowing past the opening to form a combustible gas/air mixture.

Abstract: This invention relates to a pre-mixing type burner suitable for use as a heat source for hot water heater or hot air heater. Conventional premixing type burner of this kind has a flame port section (4) having a multiplicity of slit-like flame ports (5) arranged at a right angle to the wall of a combustion chamber. The flame port (4) has a greater thickness at the central portion than at the end portions and is provided with a flat flame port surface. A passage (2) for supplying secondary air is provided at the central part of the flame port section. This conventional arrangement suffers a disadvantageous poor ignition or generation of resonance noise. If the burner is so designed that a small attached flame is formed at the flame port (5), ignition is improved but resonance noise is produced, and vice versa. The invention was made in view of the problem discussed.

Abstract: An improved process for the partial combustion of a liquid or gaseous fuel is disclosed, the process being characterized by the introduction of steam into the combustion reactor through the interior of a burner gun, the steam being introduced as a jet which rotates about its axis and diverges in the form of a cone. Apparatus for carrying out the process is also disclosed.

Abstract: A fuel gas burner produces a short fan-shaped flame and has primary utility in oil-to-gas furnace conversions. The burner includes swirl generating blades disposed in an annulus between a burner barrel carrying the bulk of the combustion gas and a mixing tube carrying approximately a 1.1 air/gas mixture. The blades induce a violent, turbulent action to the combustion gas to encourage formation of the short flame. The flame is preferably formed with a fan shape.

Abstract: A method and burner apparatus for heating and continuously melting a non-ferrous material charge, such as copper pieces in a furnace without contaminating the material charge in the furnace with non-vaporized liquid fuel thereby maintaining the metallurgical quality of the non-ferrous material charge.

Abstract: An elongated casing forming a combustion chamber and bearing a venturi type jet nozzle at one end and a fuel and compressed air supply at its opposite end, bears one or more radial passages opening to the venturi to permit a secondary fuel to feed into the flame exiting from the burner for reaction with free oxygen which is unburned from the primary fuel and air mixture entering the combustion chamber at said opposite end of the apparatus. The secondary fuel may be acetylene, methyl-acetylene and its compounds with hydrogen.

Abstract: The present invention relates to a method of controlling a substantially stoichiometric combustion of liquid fuels in a burner assembly wherein a stream of compact or atomized fuel is produced by means of an orifice or nozzle (e.g. injection, pressure, rotary atomizing nozzle) and fed into a mixing and atomizing zone in accordance with the preferably adjustable, nozzle input pressure, wherein at least part of the combustion air as an atomizing medium is introduced from the side of the axis of the fuel stream, with the flow of such air being adapted to be controlled with respect to throughput (flow rate) and flow velocity, and including a subsequent combustion of the fuel/air mixture within a combustion zone downstream of said mixing zone.

Abstract: In accordance with the teachings of the invention, the combustion system includes a combustion chamber, hearth, burners, and an air/fuel control system. The control system controls a pressurized air supply, a regulated gas supply, and means for regulating the gas supply as a function of the air pressure. The burner includes an air manifold within which is housed an air control orifice telescoped in a gas manifold and a diffuser inserted within the air control orifice for mixing the air and gas and causing turbulence of the air/gas mixture. The diffuser protrudes through an aperture in the air manifold for communication with a juxtaposed combustion chamber and hearth having a flue gas outlet. Regulated air and gas are supplied to the air manifold and gas manifold respectively and are preheated. The pessurized preheated air passes through a throat and nozzle created by the diffuser and air control orifice creating a low pressure area at ports communicating with the gas manifold.

Abstract: Oil or other combustible material polluting the sea is burned by apparatus having a partly submergible burner equipped with a transducer for generating high frequency acoustic vibrations. The transducer is surmounted by a velocity transformer designed to concentrate the acoustic vibration at a region of maximum intensity adjacent an upper end of the transformer. A float arrangement on the burner allows buoyancy to be adjusted so that the upper end of the velocity transformer is disposed a suitable distance above the surface of the water. An ignition system on the burner projects upwardly above the velocity transformer to ignite a cloud of the oil which is vaporized over the apparatus by energization of the transducer.

Abstract: A combustion method which can reduce the emission of NOx and smoke. In sharp contrast to the conventional combustion method, the method of the invention can remarkably reduce the emission of both of NOx and the smoke simultaneously, by adopting a specific flow pattern of fuel and combustion air in the combustion chamber, the pattern has been obtained as a result of studies and experiments concerning the influence of the intensity of mixing of the fuel and the combustion air on the emission of NOx.

Abstract: In a process and apparatus for the continuous burning of a fuel, the fuel is run into a combustion space where it is burnt after being ignited, making use of oxygen-containing gas run into the space. The relation of gas to fuel is changed dependent on the adjustment, of a desired oxygen content in the flue gas current. For making certain of an unchanging combustion power, the fuel inlet rate is controlled to be directly dependent on the adjustment of the oxygen content in the flue gas while keeping up an unchanging rate of input of oxygen-containing gas into the combustion space.

Abstract: A method and apparatus for modifying the flow pattern of post ignition combustion products of a flame, preferably an oil fueled and air sustained flame, are disclosed which substantially reduces the concentration of NO.sub.x emissions.

Abstract: A process and apparatus for the combustion of liquid fuel provides an extremely intense blue/violet flame having a temperature in excess of 3000.degree. F. with combustion under near perfect stoichiometric conditions without the formation of soot. The liquid fuel is atomized and mixed with air within a nozzle and enters a flame tube surrounding the nozzle as a conical stream where it is further atomized by jets of air directed to converge on the stream and mixed with secondary combustion air to obtain the desired combustion mixture. Yet further atomization of the liquid fuel-air mixtures within the flame tube can be obtained as a consequence of at least partial vaporization of the liquid fuel therein through the heat of the flame tube. An advantageous relationship exists between the size, angle and point of convergence of the air jets with the atomized conical stream, the flame tube diameter and length and the location of the nozzle therein and the fuel feed.

Abstract: Apparatus and process for treatment of materials in different phases, one of which is in a fluid phase and another of which is in a gaseous phase, wherein the material in fluid phase is introduced as a stream within the axis of the gaseous phase in helicoidal flow for subsequent passage through a confined zone whereat a substance to be treated is introduced at the level of the smallest section of the confined zone.

Abstract: A ground flare comprising a furnace body in the form of a tubular wall having a circular or polygonal cross section and a bottom open over the substantially entire bottom area and a multiplicity of burners arranged at the opening of the bottom of the furnace body. Each of the burners comprises a gas nozzle and a gas mixing tube having an open lower end with the upper end of the gas nozzle positioned therein and a substantially cylindrical inner surface. Most suitably for the prevention of black smoke and vibration, the gas mixing tube has an inside diameter 2 to 5 times the inside diameter of the gas nozzle and a length 5 to 10 times the inside diameter of the tube. Flame transfer plates provided between the upper ends of the gas mixing tubes serve to greatly reduce the number of pilot burners which otherwise would be needed.

Abstract: An oil burner with a combustion chamber has a microwave energy source connected to the fuel supply line to heat the fuel and connected to the air supply line to apply an electric field at the nozzle to the fuel spray and the area of combustion in the combustion chamber.

Abstract: An improved burner for reducing formation of nitric oxide in pulverized fuel furnaces, particularly coal furnaces. Aerodynamic spoilers extend into the wake of the primary air and fuel line to produce fuel-rich and air-rich zones near the burner. Less near-burner adiabatic combustion occurs and that which does occur, occurs fuel-rich. This reduces both the thermal formation of NO.sub.x and the chemically bound fuel nitrogen conversion to NO.sub.x. The improved apparatus may be readily added to existing burners with a minimum of modification, or incorporated into new burner designs.