Abstract: Combustion-induced instabilities are minimized in gas turbine combustors by incorporating one or more Helmholtz resonators into the combustor. First and second plates located in the head end of the combustor casing define one cavity, and a sleeve located between the casing and the liner defines another cavity. Each of the two cavities is connected to the combustion chamber by one or more throats, thus forming Helmholtz resonators. The throats of each resonator can be tubes of different lengths and/or different cross-sectional areas to provide dynamics suppression over a broad band of frequencies. The throats can also be arranged such that each throat is associated with a different portion of its respective cavity, each cavity portion having a different volume.

Abstract: A baffle is located in a recessed location relative to the inlet of a heat exchanger tube and facing the burner. The baffle is made of high temperature ceramic foam and has a plurality of flutes which define the flow path. In passing through the baffle, the velocity of the flame pattern is increased which reduces the noise level. The baffle also reduces NO.sub.x as a result of heat transfer to the baffle.

Abstract: An acoustically pulsating burner assembly which includes an elongated outer tube, a fuel supply means located within the tube, and utilizes one or more integral axially adjustable Sondhauss thermoacoustic tubular elements to generate pulsations within the burner. The acoustic pulsations are generated inside the axially movable closed end tube element provided within the burner, and these vibrations promote more efficient combustion of the fuel so as to reduce undesired emissions in the combustion products. If desired, multiple thermoacoustic tubular elements of different lengths can be advantageously used to generate pulsations of different frequencies within the burner assembly. The burner assembly is located in a furnace windbox, and can be adapted for combusting gas, oil or particulate fuels such as coal.

Abstract: A spiral, perforate ceramic baffle is placed into a heat exchanger in facing relationship with the burner and in an overhung relationship to the heat exchanger. A primary air/fuel mixture in the flame from the burner passes into the baffle drawing secondary air into the overhung portion of the baffle cooling the burner flame. Turbulence of the burner flame pattern in the baffle changes heat exchanger harmonic resonance and reduces burner noise.

Abstract: A system for actively controlling pressure pulses in a gas turbine engine combustor is provided, wherein the system includes a means for sensing pressure pulses in the combustor, a first processing means for determining the amplitude and frequency for a predominant pressure pulse of the sensed pressure pulses, a second processing means for calculating an amplitude, a frequency, and a phase angle shift for a cancellation pulse to offset the predominant pressure pulse, and an air bleed means for periodically extracting metered volumes of air from the combustor to produce the cancellation pulse, the air bleed means being controlled by the second processing means. The air bleed means includes a bleed manifold in flow communication with the combustor, a first valve in flow communication with the bleed manifold for controlling the amplitude of the cancellation pulse, and a second valve in intermittent flow communication with the first valve to control the frequency and phase angle shift of the cancellation pulse.

Abstract: A fuel fired burner comprises a chamber for receiving a premixture of fuel and air. A wall of the chamber is in the form of a flamestrip provided with a plurality of elongate slots extending through the wall. Each slot has an inlet portion which converges to an end leading to a substantially constant dimension portion. The pitch of the slots along the chamber wall is P, the width of each slot is w, and the length of the constant dimension portion is L. The dimensions of the flamestrip are arranged such that L/w.gtoreq.10 and P/w.gtoreq.2. A burner including such an arrangement reduces the likelihood of resonant combustion noise being generated when enclosed within a heating appliance.

Abstract: A system and method for resisting thermoacoustic oscillations in systems comprised of hot and cold components is disclosed. More particularly, a combined cycle power generation system 32 having a gas turbine 40, a gas turbine discharge duct 34, and a gas turbine recuperator 36 and 38 is disclosed. The system 32 is designed to resist severe thermoacoustic oscillations over its entire load range by providing for an asymmetrical arrangement of the hot section L-l, including the gas discharge duct 34 and the plenum 36 of the recuperator, and the cold section L-l, including the heat exchange tubes 38 of the recuperator. Also disclosed is a steam generation system 42 having a plenum 46, a burner 48, and a furnace 44. The steam generation system 42 is also designed to resist severe thermoacoustic oscillations by providing for an appropriate burner length L and by providing for an asymmetrical arrangement of a hot burner section L-l and a cold burner section l within the burner 48.

Abstract: Pressure variation of combustion noise is detected by a microphone set in a combustion chamber, and the pressure propagation characteristic for the path from the gas flow control valve to the microphone is identified while the combustion apparatus is operating, and then an adaptive control is made using one signal detected by an microphone and the other signal produced by passing the signal of the microphone through a filter, and then a corrected anti-phase signal of a combustion noise is computed by the coefficient updating circuit, and the computed result is inputted to a gas flow control valve.

Abstract: In a secondary burner for a gas turbine combustion chamber, a fuel feed (2, 3) arranged in a combustion chamber wall (1) is surrounded by an annular air duct (4). The air duct (4) communicates, by means of at least one supply tube (5), with a through-flow Helmholtz resonator (6). The outlet from the Helmholtz resonator damping tube (7), which is configured as an annular duct, is located in the region of the burner mouth (8) in the secondary combustion space (9).

Abstract: The present invention involves a combustion box of a gas furnace which experiences oscillating combustion. The combustion box employs an opening in the housing which is tautly covered with a diaphragm made of elastic material such as silicone rubber. The elastic diaphragm transmits noise and vibration generated by the oscillating combustion of the gas burners in the combustion chamber and thereby dissipates that vibration and noise.

Abstract: The present invention provides a relatively compact-sized pulse combustor which efficiently reduces an undesirable explosion and combustion noise without any bulky muffler. In the pulse combustor of the invention, a compensating sound is generated in an exhaust conduit synchronously with pulsative explosion and combustion. The compensating sound has a sound pressure identical with that of a noise in the exhaust conduit but a phase opposite to that of the noise, thus effectively compensating the noise in the exhaust conduit and efficiently reducing the noise from an exhaust outlet.

Abstract: An apparatus and process using a pulse combustor to atomize a liquid or slurry is provided. The apparatus includes a pulse combustor for generating a stream of atomization fluid and an oscillating flow field and introduction apparatus for introducing to the influence of the oscillating stream of atomization fluid a liquid or slurry to be atomized. Furthermore, an improved pulse combustion atomizer employing a T-shaped burner is provided.

Abstract: An improved method and apparatus for actively controlling a combustion process such as a waste incinerator by means of a spatial and temporal synchronized injection of fuel. The improved method and apparatus employs an active control system which controls the intentional formation of large scale, coherent vortices and the synchronized injection of the fuel supply at various locations relative to the formation of the vortices. The preferred apparatus comprises an actuator or similar structure that is adapted for producing and stabilizing discrete, large scale vortices in a combustion device. In addition, another device controls or modulates the injection of the fuel into the vortices at the optimal location and timing relative to the vortex cycle. As applied to an incinerator, this method can be optimized to ensures that the fuel and waste are introduced into the highest temperature locations, were extended residence times are obtained by trapping the fuel and waste inside the vortices.

Abstract: A combustion noise suppression system for a combustor assembly includes a number of holes formed in the combustor housing at a distance from the location at which an air and fuel mixture is introduced into the housing and ignited to produce flame.

Abstract: An atmospheric gas burner assembly producing relatively low oxides of nitrogen (NO.sub.

Abstract: In direct fired fluid burner heater of the type where fuel is continuously injected and burned at one end of a cylindrical combustion chamber and combustion gases discharged at an opposite open end pass through a heat exchanger for heating a circulating medium, and where high heat capacity is achieved for a given chamber size by swirling the flame in the combustion chamber, acoustical low frequency buzzing is controlled by restricting the discharge area through which exhaust gases flow downstream of the heat exchanger.

Abstract: An apparatus and process using a pulse combustor to atomize a liquid or slurry is provided. The apparatus includes a pulse combustor for generating a stream of atomization fluid and an oscillating flow field and introduction apparatus for introducing to the influence of the oscillating stream of atomization fluid a liquid or slurry to be atomized.

Abstract: A gas boiler having a boiler unit constructed by interconnected boiler sections each having an internal waterway bounded by one or more heat transfer surfaces. Baffles on the boiler sections define serpentine flue passages, and the baffles include bypass openings formed by notches and/or slits to suppress standing waves and associated noise. A burner includes a conical burner element having burner ports arranged in clusters to enhance the flame distribution and stability. A distributor cone nested within the burner element provides a pressure drop for noise suppression. The blower shaft is equipped with a magnetic plastic washer which effects a seal against air infiltration while allowing the blower shaft to shift from side to side.

Abstract: An inshot gas burner nozzle having a flame retention insert that enhances flame stability and reduces noise, the insert comprising a central opening, secondary openings of smaller diameter arranged circularly around the central insert, and a plurality of restricted peripheral openings in the form of stepped notches. The nozzle further comprises plenum chambers which have restricted outlets thereby creating back pressure within the plenums to improve cross-ignition of adjacent nozzles.

Abstract: A gas-fired heat gun has a housing, a nozzle in the housing for directing a stream of a combustible gas in a predetermined direction along an axis in the housing, and at least two mixing tubes including an upstream tube and a downstream tube in the housing coaxial with the nozzle and downstream therefrom. Each tube has a large-diameter upstream end and a small-diameter downstream end with the downstream end of the upstream tube spacedly received within the upstream end of the downstream tube so that air is entrained axially into both upstream ends by the combustible-gas stream. A combustion chamber is provided in the housing coaxial with and immediately downstream of the downstream end of the downstream tube.

Abstract: An apparatus for controlling pressure instabilities in a combustion chamber. The apparatus includes a detector which detects combustion chamber pressure and outputs a signal indicative of that pressure. A controller then receives the output signal, delays it by a selectable amount of time, and outputs the resultant delayed signal to a pressure chamber device. The pressure chamber device controls the fuel pressure in a fuel line which supplies the combustion chamber. In one embodiment, this pressure chamber device is a cylindrical chamber with closed ends. The pressure chamber has inlet openings and outlet openings which are connected to the fuel line. In some embodiments the bottom of the pressure chamber device includes an elastic diaphragm activated by an electric signal from the controller. In some embodiments the controller involves a delay line for delaying the output signal from the detector.

Abstract: Gas burner, particularly for household appliances, comprising a burner body (1) having a peripheral side wall (5) defining an enclosure with an outward opening and at least one air-gas mixture supply orifice (13), which enclosure is adapted to contain a "soft" flame able to withstand sudden pressure variations of the primary air brought to the burner and to re-activate the flames of the burner should they be blown out, characterized in that it further comprises at least one chamber (15) situated behind the supply orifice (13) of said enclosure (11) and itself having a gas mixture supply orifice (16) with a cross section substantially equal to or greater than that of the supply orifice (13) of the enclosure, this chamber being configured so that the air-gas mixture which is contained therein forms a buffer cancelling out or attenuating the sudden pressure variations of the primary air admitted into the burner and so that the flame of the enclosure is maintained.

Abstract: An improved inshot gas burner for use in gas furnaces, clothes dryers and other like gas appliances providing improved combustion flame characteristics. A novel burner body design is tuned at manufacture solely by the insertion therein of a flame retention device which has been configured, sized and shaped for the aerodynamic features thereof which will produce proper flame retention and burner fuel loading for the air flow characteristics of the particular appliance model in which the burner will be used. The gas burner is provided with an outwardly flared outlet port downstream of the flame retention device continuous with an outwardly flared diametrically opposed flame carry-over ports. These flared port constructions have produced superior flame characteristics, particularly when used in high-efficiency, forced draft furnaces.

Abstract: A furnace having a housing, a combustion chamber within the housing, and a burner associated with the combustion chamber is provided with a sound enclosure housing including a muffler portion. The muffler portion comprises an elongated serpentine passage having an air opening at one end.

Abstract: A pulse combustion apparatus comprising a metal pipe member, an exhaust chamber, and an insert member. The pipe member has two open ends and its inner diameter is uniform over its entire length. The first open end of the pipe member is closed, and the second open end thereof is connected to the exhaust chamber. The insert member is located within the pipe member such that it and the pipe member define a combustion chamber within the pipe member, close to the first end thereof, and also an exhaust passage connecting the combustion chamber to the exhaust chamber and having a cross section area smaller than that of the combustion chamber. The combustion chamber and the exhaust passage constitute a Helmholtz resonator which realizes pulse combustion of the fuel gas.

Abstract: A blower burner is provided for a boiler heated with fluid fuels with a blower casing, which incorporates on one side the blower with the attached drive motor and where the fire tube of the burner comes out on the other side. The motor and the fire tube form protruding parts on opposite sides of the blower housing. The rear side of the fire tube protrudes beyond the side of the casing disposed toward the drive motor and the rear side of the fire tube protrudes into a cover extension attachment of the blower casing. The burner is provided with a pressure controller, where the air pressure inside of the fire tube element is measured by the input sensor signal and where the blower speed is the variable controlled by the pressure controller. Furthermore, a sound absorbing means is provided for the blower burner.

Abstract: A furnace is provided for combusting liquid or gaseous fuel which has a combustion assembly with an internal cavity that has a mixing chamber and a combustion chamber. A flame tube is disposed intermediate the mixing chamber and the combustion chamber. The combustion assembly has an outlet which is adapted to exhaust the gases which result from combustion of the air-fuel mixture. An ignitor rod for igniting the air fuel mixture is also provided.

Abstract: The gas burner comprises a mixer, a conical transition member adjacent thereto on which a cylindrical burner shell with openings and whose top is closed by a burner lid is mounted. Clamped between the burner lid and the transition member is a throttling cylinder which is filled by the super-stoichiometric gas mixture at super-atmospheric pressure. In order to avoid burner pulsations the cylinder has throttling openings whose total area is 2 to 10% of the total area of the openings. The throttling openings are in a plurality of circular rows above one another in such a manner that they are on a respective vertical line. Vertical, imperforate sections of the burner shell are opposed to the lines so that the mixture jets from the throttling openings do not impinge directly on the openings. The cylinder is provided at a coaxial spacing of 5 mm from the burner shell.

Abstract: Radiant tube space heating appliance includes a burner assembly (12), air flow therethrough being induced by a fan (14) by way of a restricted air inlet orifice (34) communicating with a stabilizing chamber (32) leading to the burner head (26) for smoothing and silencing the air flow; the burner head including a flame stabilizing matrix (40), conveniently formed from windings of flat and corrugated stainless strips (42,43) which define through apertures of substantial axial length. The appliance may further include a turbulator insert (50) in the radiant tube formed as a corrugated strip (52) of stainless steel or similar material which is twisted to form a helix.

Abstract: An improved smoke suppressant apparatus for flare gas combination comprising a flare housing and a liner cylinder member coaxially disposed therewithin, an annular orifice channel formed between the liner cylinder and the flare housing. A first flare conduit is in fluid communication with the orifice channel and a first flare gas portion passing through the flare conduit is discharged from the orifice channel at the upper end of the flare housing as a perimeter zone discharge configured as a relatively thin cylindrical layer of flare gas. A second flare conduit may be provided in fluid communication with the inner core of the liner cylinder to discharge a second flare gas portion therethrough as an inner zone discharge, and a liquid seal is provided to permit flare gas to pass via the second flare conduit only when the pressure of the inlet flare gas exceeds a predetermined value.

Abstract: A pulsed combustor comprising at least one aerodynamic diode, a diffuser, fuel injectors, combustion chamber/duct, igniters, and muffler providing plug type flow with successive ignition and wave generation at the hot gas interface of the previous pulse. The downstream wave of each pulse propagates through the muffler whereas the upstream wave of each such pulse is at least partially reflected downstream with the diode(s) and diffuser minimizing reverse flow and maximizing pressure gain in the cumbustor.

Abstract: An improved pulsating processing system for thermal, chemical, and physical processes which employs nonlongitudinal acoustic modes in a processing chamber to enhance the processing. An acoustically resonant processing chamber is provided as the processing vessel. A frequency tunable pulse combustor or other selectively variable frequency acoustic exciter is positioned to excite natural nonlongitudinal acoustic modes in the processing chamber. Material introduced into the processing chamber is thereby subjected to nonlongitudinal acoustic pulsations while the material is being processed. Also disclosed is an improved frequency and amplitude tunable pulse combustor which may be employed to excite the natural acoustic modes in the processing chamber. One disclosed embodiment is a system for drying a slurry of material such as kaolin. The nonlongitudinal acoustic excitations in the system result in improved moisture removal and particle heating.

Abstract: An apparatus and method for continuously treating material for performing such functions as burning, roasting, smelting, coking, melting, high temperature chemical reactions and the like in a combustion chamber wherein the chamber or an extension thereof, is tuned to permit combustion gases therein to resonate and to thereby effect maximum combustion efficiency. In particular, the invention concerns controllably varying the geometry of the combustion chamber, such as the length of a pipe or tubed section thereof in accordance with the variables of combustion occuring therein, so as to optimize efficiency of combustion and the reaction which takes place between the burning material and the material being treated or reacted on. In addition to effecting such reactions, the apparatus is also operable to effect the transfer of the heat of combustion to a heat transfer medium, such as water for generating steam or other form of heat transfer medium to maximize the utilization of the energy generated.

Abstract: A steam generator having substantial thermal capacity for producing high quality steam used primarily for downhole steam generation in tertiary oil recovery. Incorporated in the generator is a novel high pressure, high heat release combustor, utilizing high pressure gaseous fuel and compressed gas oxidizer such as air, wherein thermal and mechanical stresses on the combustor structure are controlled. A method for controlling combustion induced mechanical stresses on the combustor through fluid injection is also disclosed. Disclosed designs provide substantially increased combustor life in "Downhole" Steam Generation service. The burner employs an ignition technique utilizing gaseous injection of a pyrophoric compound such as triethylborane (TEB).

Abstract: A combustion chamber subject to the build-up of acoustic vibrations may have the vibrations inhibited by an electrode system which can be modulated to produce anti-noise. Sound is sensed by a microphone which may be mounted remotely to produce a control signal coupled to a voltage generator feeding the electrode system.

Abstract: A flare gas burner is described in which a deflector shell approximating a half Venturi is disposed about the upper end of a waste gas delivery pipe equipped with standard pilot-flame igniters and flame stabilizers. A manifold on the lower end of the deflector delivers motive fluid (air, steam) under high pressure into the passageway between the deflector and pipe. The fluid is directed by the inwardly inclined upper lip of the shell into the path of emissions from the waste gas pipe. Heat shields and noise shields are incorporated into the assembly. Additional whirling and turbulence is imparted to the stream of motive fluid by appropriate shaping of spacer plates securing the deflector to the waste gas pipe.The structure is less complex than previously known devices, has improved ease of maintenance, and gives excellent performance in smokeless flaring of waste gas.

Abstract: A heater with a burner which is supplied with liquid fuel by a metering pump and a fuel supply line, is provided with a throttle in the fuel supply line between the metering pump and the burner. The throttle is preferably formed by a long throttle element, in particular a wire, which is placed and inserted into a fuel line connector that is rigidly connected to the burner. The throttle which is formed in this way smooths out the volume flow of fuel to the burner and reduces the dwell time of the fuel, especially in the fuel line connector, in order to prevent gas evolution and the associated formation of vapor bubbles.

Abstract: An improved combustion chamber for a condensing furnace comprising an elongated cast body having a mixing chamber for receiving fuel and air and an expansion chamber communicating with said mixing chamber, a fuel inlet in said body communicating with said mixing chamber, an air inlet in said body communicating with said mixing chamber and means for igniting the air fuel mixture in said mixing chamber, the fuel inlet and the igniting means being opposed to one another to enhance the ignition of the fuel and air in the mixing chamber. An important feature of the invention is the critical ratio of the transverse cross sectional area of the expansion chamber to the transverse cross sectional area of the mixing chamber for maintaining continuity of operation. Such ratio should be about 2/1 to 2.4/1. In a preferred form of the invention, the igniting means is a spark plug and the spark plug opening into the mixing chamber is co-axial with the fuel inlet.

Abstract: Safety system designed to eliminate liquids entrained or condensed, and to limit the heat radiation and the intensity of the noises received in the flaring or dispersion of gases from the production, processing and transportation of crude hydrocarbons, and elaborated on land or offshore.The system according to the invention involves a chamber 6 such as a flare-base flask connected to at least one flare stack which includes: a back-pressure device 11 and a tip 5 or an orifice for venting to the atmosphere, and means to pulverize into a mist any drops of liquid remaining in the gas flow, and to insure, rapidly, an intimate mixture of the gas with the ambient air.This system can be installed on land, at sea, on any type of fixed or floating support.

Abstract: A high pressure gas flare using the Coanda effect has a noise attenuator surrounding the high pressure gas outlet slot. The noise attenuator is in the form of one or more upwardly diverging frusto-conical shields which may be spaced apart or closed with the body of the flare. The attenuator is particularly useful for steam driven flares.

Abstract: A silencer unit has charging- and exhaust-side silencers which are integrally formed into a double-cylinder housing. The housing has an outer cylinder and an inner cylinder disposed in the outer cylinder. The charging-side silencer is connected to an air charging pipe of a pulse combustor to attenuate noise generated from the charging side of the combustor. The exhaust-side silencer is connected to an exhaust pipe of the combustor to attenuate noise generated from the exhausing side of the combustor. The charging-side silencer has a first low-frequency sound arresting chamber defined in the inner cylinder and a first high-frequency sound arresting chamber defined between the inner and outer cylinders. The exhaust-side silencer has a second low-frequency sound arresting chamber defined in the inner cylinder and a second high-frequency sound arresting chamber defined between the inner and outer cylinders.

Abstract: A noise reducing heat exchanger assembly for a combustion system is disclosed. The heat exchanger assembly includes a plurality of side by side heat exchangers each having a single inlet for an inshot burner. An auxiliary port is located just above each burner inlet. A coupling chamber may be used to interconnect the auxiliary ports to allow acoustical coupling between the heat exchangers and to substantially prevent potential fluid flow between the heat exchangers and the surroundings of the combustion system. This heat exchanger assembly is particularly suitable for use as part of an induced draft combustion furnace.

Abstract: A combustion chamber for pulsating combustion is separated by a partition wall (12) into a first chamber (14) to which there is connected an axial inlet (20) for the fuel stream, and a second chamber (16) for diverting the combustion gases through an outlet (18). The gases depart via side chambers (44) from the first to the second chamber at the edges of the partition wall. A hot body (24) is arranged at a given height above the partition wall in the first chamber, said body being intended for being heated during operation to a temperature which is substantially higher than the carbonization temperature of the fuel and which screens off a central area of the partition wall.

Abstract: The physical size of an inlet plenum (2) for a cluster of pulse combustors (1) may be reduced while maintaining a tuned condition for noise cancellation by constructing the plenum with an annular chamber (8) having internal baffles (20, 21) which make the acoustic path length through the annular plenum (2) substantially larger than its circumference.

Abstract: Oscillation in a combustion chamber is avoided by providing in the combustion chamber an oscillatable wall which is oscillatable by oscillation occurring in the combustion chamber. The oscillatable wall may be a wall of low flexural rigidity or a flexurally rigid wall connected at its edges with a flexible coupling to adjacent rigid portions of the combustion chamber. Oscillation of the oscillatable wall is damped by being provided with a damping layer or by being connected to a mechanical or hydraulic damper.

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: A forced-draft gaseous pre-mix power gas burner having a shaped and perforated burner plate wherein the hole sizes are related to the plate thickness and the holes are formed in a unique pattern, all of which prevent flashback and noise or screech while at the same time flame stability is greatly improved. The burner plate is easily installed and removed, is essentially free from stresses which would distort it, and readily fits positively and accurately within the burner assembly without resorting to welding or other special fasteners. A novel ignition-improving device for effecting a stagnant flow at the ignition arc location provides for quick and reliable ignition of the gas at all times.

Abstract: An oil burner including an oil atomizing nozzle to be mounted upstream of a ransverse wall in a cylindrical flame tube and to discharge oil through an aperture in the wall through which air also passes into a cylindrical mixing tube positioned co-axially within the flame tube and open at its downstream end. The flame tube has a length at least twice its diameter and a diameter between 2.0 and 2.5 times the diameter of the mixing tube. At least one passage adjacent the transverse wall communicates between the interior of the flame tube and the interior of the mixing tube to recirculate combustion gases from the downstream end of the mixing tube to the upstream end thereof. The peripheral wall of the mixing tube adjacent its downstream end is perforated.

Abstract: A portable safety flare for combustion of waste gases is disclosed for the combustion of combustible gas from oil wells, combustible waste gas from oil refineries and chemical plants, and particularly where it is not desired to go to the expense of installing a flare stack or for use in exploratory operations close to residential areas, or where the flare stack is not functional so that shut-down of the refinery would be required until the flare stack is repaired, and which preferably includes a vehicular trailer body with a floor and having stabilizing supports and side walls movable from closed positions for transport to elevated and heat shielding positions for use, and with provisions for noise suppression, the floor having waste gas burners thereabove with pilots and ignitors for staged combustion of the gas, the floor and walls being protected against the heat generated by the combustion, the trailer having sources of pressure fluid for operating various components and a source of igniting gas, and a mo

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.