Abstract: Air trim control actuator mechanically connects a fuel flow device to an air flow device for setting the air to fuel ratio in combustion apparatus. An air to fuel ratio control unit is responsive to electrical input signals from an oxygen sensor that monitors the combustion products in the stack emissions. The air trim actuator includes a pivotally mounted input arm that is mechanically connected to the control unit and is pivoted to a preselected position corresponding to the selected boiler load. The input arm is connected by a link to an output arm which is pivoted through a preselected range of movement to control the position of the damper. The output arm has an elongated arcuate slot for receiving the end of the link. The output arm is pivoted to a position corresponding to the pivoted position of the input arm for selectively positioning the damper to provide air flow to the boiler for the desired air/fuel ratio.

Abstract: A control system for an induced or forced draft combustion apparatus has a single pressure transducer for providing an electrical signal indicative of pressures by alternately responding to the fuel pressure to the combustion apparatus and the fuel pressure plus the induced draft lower suction pressure. The signal output of the transducer is connected to a controller for controlling the fuel flow to maintain a predetermined fuel/air ratio for efficient and safe combustion of the fuel in the combustion apparatus.

Abstract: A variable firing rate burner with a throttle valve assembly that regulates fuel and air intake while maintaining a substantially constant fuel/air ratio over a wide fuel/air flow rate range. The throttle valve assembly includes a pivotally mounted throttle plate that seats on an input manifold, the throttle plate being moved by a driver between low and high firing rate positions. Fuel and air are drawn through the throttle valve assembly and into a mixing chamber by a blower and directed to a flameholder where ignition occurs.

Abstract: Method and apparatus for controlling the distribution of secondary air (30) between at least two fuel burners (14,16) in a multiple fuel combustor (16). Total chemical energies of the individual fuel streams (44,60) are determined and compared (64,66) with the total combustor chemical energy input (62) for controlling biasing means (32,34). The determination of at least one individual fuel total chemical energy content (60) may optionally include a prompt neutron activation type analyzer (48) for on-line measurement of specific fuel chemical energy (59).

Abstract: An automatic air-fuel ratio control apparatus for use in a combustion system of a type in which combustion air is preheated, which is so arranged that a push rod depresses one end portion of a rocking lever in accordance with temperature of preheated combustion air and consequently the other end portion of the rocking lever depresses a valve member to correct pressure of working fluid for controlling a flow of fuel so as to obtain best air-fuel ratio, and further that a bearing member for pivotally supporting the rocking lever can be diagonally shifted to change the air-fuel ratio.

Abstract: The movable elements of two normally closed valves are actuated by a thermal element responsive to ignition at a pilot burner supplied fuel through one of the valves. The two valve elements form a mechanical train from the thermal element which simultaneously unseats the second valve controlling fuel to the main burner and releases a manually operable mechanism with which the pilot burner valve is initially unseated for ignition.

Abstract: A fuel supply control system including a major area diaphragm and a minor area diaphragm defining therebetween a reference pressure chamber. A control pressure chamber is located adjacent the major area diaphragm on a side thereof opposite to the reference pressure chamber and a controlled pressure chamber is located adjacent the minor area diaphragm on a side thereof opposite to the reference pressure chamber. A valve is connected to the diaphragms for regulating the opening of an orifice of a fuel passage and the controlled pressure chamber serves as a chamber of the fuel passage. The control pressure chamber is connected to a combustion air supply passage system, and the reference pressure chamber is connected to a portion of an air supply and exhaust passage system, in which the pressure is lower than the pressure in the combustion air supply passage system.

Abstract: The invention utilizes a pump for delivering oil to the atomizing nozzle of a combustion chamber. The system includes a tank with a free piston by which oil introduced at one end from the pump forces water out at the other end at the same pressure as the oil discharged from the pump. The oil and water are then discharged through a pair of adjacent nozzles and mixed and then through an additional nozzle to further mix the oil and water and then conducted to the combustion chamber atomizing nozzle.

Abstract: A burner having an air intake at atmospheric pressure, a gas (fuel) supply line and a combustion chamber in which gas from the latter line burns in the presence of atmospheric air drawn in from the intake, is provided with a swingable or rotatable flap-type valve member which controls the volume rate of flow of the air to the combustion site. According to the invention, the position of the valve member is controlled by a parameter generated by the air stream and in response to the pressure in the gas supply line to maintain the air factor (ratio of air to gas) substantially constant. To this end a membrane type pressure detector responds to the pressure in the gas supply line and is connected by a mechanical force transmission mechanism to the flap or other valve element.

Abstract: A combustion control apparatus comprises a premix combustion burner requiring primary air, an injector disposed in a primary air passage and including a constricted section having a fixed diameter and length, an enlarged section communicating with the constricted section and a fuel injecting port disposed concentrically with the constricted section and in a predetermined region, and a pressure regulator disposed in a fuel feed passage communicating with the fuel injecting port, the arrangement being such that the pressure regulator is controlled so that the pressure difference between the outlet section of the pressure regulator and the inlet section of the injector may be within the fixed range of the pressure difference produced between the inlet and constricted sections of the injector on the basis of the amount of primary air at the time of the lowest input, thereby maintaining the ratio between the amounts of air and fuel at a constant value and securing combustion stability and high combustion efficienc

Abstract: A method and an apparatus for dosing the air-fuel mixture in burners of the type which is formed with an evaporator tube (9) through which fuel and some amount of combustion air is introduced in the combustion chamber (1) and in said combustion chamber is mixed with further combustion air and is inflamed. The optimum amount of combustion air is determined for different amounts of fuel and for different reference temperatures in a predetermined point of the evaporator tube (9) adjacent the mouth (10) thereof in the combustion chamber (1), and the temperature of the air-fuel mixture is measured by means of a thermo element (41) in the said point of the evaporator tube (9).

Abstract: An oil burner of the type of pumping up a fuel oil is disclosed which has a first oil level setting means of an airtight type having an overflow pipe means constantly immersed at the lower end thereof in a fuel oil to be pumped up to the first oil level setting means and has a second oil level setting means disposed below the first oil level setting means and directly connected to a fuel oil supply tank. A fuel oil supplied from the second oil level setting means is drawn up to the first oil level setting means by a pumping-up means and subsequently supplied through a supply pipe to a combustion means. The level of a fuel oil in the first oil level setting means is kept constant at a position above the outlet end of the supply pipe. The overflow pipe means may be movable in the vertical direction so as to vary only the supply rate of a fuel oil.

Abstract: An oil burner having an atomizing nozzle receptive of a supply of oil through an oil tube therein and receptive of a supply of air under pressure through an air tube therein for atomizing the oil, includes an oil shut-off valve device which is responsive to the pressure of the air in the air tube for normally preventing the passage of oil from the oil tube to the nozzle until the air pressure rises above a given value and for shutting off the passage of oil from the oil tube to the nozzle when the air pressure falls below a given value.

Abstract: An improved nozzle spray type burner including a combustion chamber, a housing having an exhaust passage coupled to the combustion chamber, a fan mounted in the housing for directing air through the exhaust passage to the combustion chamber and a fuel spray nozzle in the exhaust passage for spraying fuel into the flow of air in the exhaust passage. The improvement includes a first mechanism associated with the fan to control the flow rate of air in the exhaust passage, and a second mechanism associated with the nozzle for controlling the amount of fuel sprayed from the nozzle. The first and second mechanisms are arranged to cooperate to control the degree of combustion of the fuel with the air in the combustion chamber.

Abstract: A method and apparatus for controlling the amount of smoke produced when flaring a combustible gas is disclosed. The invention employs steam which is also passed to the flare .

Abstract: The invention is a fuel burner system including an electrical control circuit for initiating fuel flow to a burner in response to a call-for-heat from a condition responsive sensor, and an electrical ignitor for igniting the fuel emanating from the burner. Combustion or purging air is directed to the burner by a fan, the integrity of which is monitored by a sensor circuit that produces a fault signal in response to rotation of the fan at any speed in a given range of speeds. An inhibit circuit inhibits the control circuit to prevent opening of a fuel supply valve in response to the presence of the fault signal. Fan rotation at speeds either above or below a predetermined normal range indicates a malfunction and results in the fault signal that prevents the initiation of fuel flow and a try for ignition.

Abstract: The invention has for its object to provide a control unit for the air choke in an oil burning installation which affords good fuel economy and is simple in construction, while being at the same time easy to mount and adjust. The control unit is composed of a piston cylinder (14) the pressure side of which is connected to the pressure side of the fuel pump (22) of the plant in such a manner that its piston (24) performs a working stroke when the pump starts and returns to the starting position when the pump stops. The piston rod (18) of the piston cylinder unit is coupled to a throttle which opens as a result of said working stroke and closes on the return movement.

Abstract: The pneumatically controlled, variable oil pressure regulator of the present invention maintains a selected combustion ratio of oil and air to a furnace and includes in preferred embodiments a diaphragm housing for a flexible air diaphragm and a flexible oil diaphragm, each preferably including a rolled peripheral lip portion for maximum extensibility and connected to a valve plug having the shape of a solid of revolution formed by rotating a convexly curved surface such as an arc of a circle of less than approximately 90.degree. or a corresponding portion of a hyperbolic, parabolic, or elliptical curve, which intersects the longitudinal axis of the valve plug stem about the longitudinal axis thereof to approximate an ellipsoidal shape whereby very low minimum flow rates can be effected without oscillation of the valve.

Abstract: Apparatus and method for changing the calibrated linkage relationship between two flow control devices of combustion apparatus without impeding the normal operation of the associated process. Means are provided, responsive to remote, manual or automatic control, to calibrate a jackshaft linkage type of control apparatus in order to provide for range changes and zero adjustment.

Abstract: Control method and apparatus for optimizing the operation of a natural draft combustion zone through which a conduit containing a process fluid to be heated passes, by decreasing the supply of combustion air until one or more of the following predetermined limiting conditions is reached: maximum CO in the flue gas, minimum O.sub.2 in flue gas, minimum draft in the combustion zone, maximum temperature of the outer surface of said conduit, and increase in the rate of fuel addition above a minimum amount. When a limiting condition is reached, the supply of combustion air is increased until the limiting condition is no longer present, and the cycle then repeated.

Abstract: The well-known "Jack-shaft" or "Single-point" positioning or a two-point parallel combustion control system has been modified by a trim link member articulated on the master arm to introduce a phase angle between the master arm associated with fuel supply adjustment and the slave arm associated with the combustive agent supply adjustment in a combustion engine, boiler, heater, or the like, thereby to permit oxygen or air-to-fuel ratio adjustment at all times.

Abstract: Control method and apparatus for optimizing the operation of a natural draft combustion zone through which a conduit containing a process fluid to be heated passes, by decreasing the supply of combustion air until one or more of the following predetermined limiting conditions is reached: maximum CO in the flue gas, minimum O.sub.2 in flue gas, minimum draft in the combustion zone, maximum temperature of the outer surface of said conduit, and increase in the rate of fuel addition above a minimum amount. When a limiting condition is reached, the supply of combustion air is increased until the limiting condition is no longer present, and the cycle then repeated.

Abstract: A conduit for feeding a combustible waste gas to a ground flare is divided into a plurality of branch pipes each connected to burners of the ground flare. A stop valve is mounted on each of the branch pipes except the first pipe and provided with a limit switch for detecting the closing of the valve. A pressure detector is mounted on each of the branch pipes except the last pipe. The valve on each branch pipe opens in response to an opening signal from the pressure detector on the preceding branch pipe and closes in response to both a closing signal from that pressure detector and a signal from the limit switch on the valve on the following branch pipe, whereby the number of branch pipes used for feeding the waste gas is controlled in accordance with variations in the feed of waste gas.

Abstract: In a flare stack system for the flaring of waste gases, in which the flare stack is equipped with steam injection parts, such as nozzles or manifolds, adjacent the flame zone at the outlet end of the stack, means are provided for alternate injection of air from a blower, or live steam, through the steam injection parts. The alternate flow is controlled by two pneumatically controlled valves, one in the blower air line, and the other in the steam line, such that when one valve is closed, the other is open, and vice versa. The objective of the alternate supply of air and steam is for the purpose of cooling the steam injection parts when the full flow of steam is not required, because there is no waste gas flow or only a minimal gas flow. In that case, the heat of the maintenance gas flow may be sufficient to injure the steam injection parts, which must be cooled by passage of a gas through them.

Abstract: A gas-fired boiler installation with control of the supply of combustion components, provided with a combustion space that upwardly is in communication with a boiler flue and at the bottom side is confined by a burner bed with atmospheric burners having interposed venturi tubes which upon throughflow by the gas controllably supplied via a valve, draw in primary air. Between the elements of the burner bed, from the bottom side thereof, secondary air can be drawn into the combustion space while the secondary air is controllable in conjunction with the control of the gas supply by a control valve.

Abstract: A sensor of inadequate combustion conditions at a main burner, comprising a small auxiliary gas burner the primary air-gas flow to which consists of a predetermined fraction of the flow of primary air and gas to the main burner plus a predetermined fraction of the flow of secondary air supplied to the main burner, with no secondary air supply of its own. The total combustion air thus supplied to the auxiliary burner is made such that the flame at the auxiliary burner extinguishes when the combustion air at the main burner flame becomes inadequate for satisfactory combustion but is still sufficient to maintain a flame at the main burner. A flame sensor at the auxiliary burner produces indications of absence of flame at the auxiliary burner, which in turn indicates inadequate combustion conditions at the main burner.

Abstract: An oil burner for distillate fuel including a blower and air guiding elements producing a rapidly whirling pattern of combustion air close to the burner nozzles to produce an extremely hot fireball close to the nozzles. The fireball, once ignited, provides reliable continuous ignition of the entering fuel, obviating the usual requirement of continuous electrical ignition, and permitting the use of low voltage for the initial ignition. The blower produces an excess of air over that needed for combustion, and the excess air cools the combustion chamber externally to obviate any necessity of forming the chamber of stainless steel, cast iron or the like. When the burner includes a plurality of burner nozzles intended for use singly or simultaneously, automatic means are provided for supplying the necessary carefully regulated amounts of combustion air.

Abstract: A fluid fuel burning system is mounted in a firetube and generates heat of combustion which is transferred to industrial fluid flowing through a vessel in which the firetube is mounted. The air for combustion flows into the burner as primary air mixing with the fluid fuel and a secondary air which is regulated as it flows to the combustion being completed downstream of the burner. The regulation is carried out with a damper positioned in the entrance to the firetube.

Abstract: Apparatus and method for changing the calibrated linkage relationship between two flow control devices of combustion apparatus without impeding the normal operation of the associated process. Means are provided, responsive to remote, manual or automatic control, to calibrate a jackshaft linkage type of control apparatus in order to provide for range changes and zero adjustment.

Abstract: The control of the flow rates of multiple fuel streams to furnace burners is accomplished by manipulating the flow rate of each fuel stream in response to a calculation of the heat duty which must be supplied by the respective fuel stream. Where the supply of a preferred fuel is variable, the flow rate of the other less preferred fuel stream is varied in response to changes in available supply of the preferred fuel to insure that sufficient fuel is available to the burners to maintain a required process temperature.

Abstract: A fluid flow sensor fabricated by integrated circuit techniques is positioned within fluid flow passages for measuring the mass flow of fluid therethrough. The sensor comprises three solid state circuit devices wherein two are fabricated on a chip separate from the third device.The first device is responsive to forced convective heat transfer by the fluid flowing thereover for generating a first electrical signal. The third device is responsive to temperature of the fluid thereover for generating a second signal and the second device is responsive to both said first and second electrical signals for maintaining said first device at a predetermined temperature above said third device.A fuel metering system for internal combustion engines is described utilizing a fluid flow sensor for measuring the mass flow of both fuel and air into the throttle body. Circuit means responsive to said sensors operate to maintain a predetermined fuel-air ratio in said internal combustion means.

Abstract: The ratio of fuel to oxidant in a gas mixture to main burners in a furnace, wherein the fuel is of variable composition, is controlled to a predetermined level by burning a portion of the fuel in a control burner, adjusting the oxidant to obtain a ratio of fuel to oxidant near the stoichiometric ratio in the control burner and supplying the main burners with independent preset multiples of the fuel and oxidant flow in the control burner such that the predetermined ratio of fuel to oxidant is achieved.The stoichiometric ratio is determined by automatic searching for the peak value of a burning or burned fuel property which has a maximum value as a function of the fuel/oxidant ratio at or near the stoichiometric ratio. For example, the temperature of the burned fuel is a property which may be used to find the stoichiometric ratio.

Abstract: An improved embodiment of the rotary fuel-steam burner system described in copending application Ser. No. 664,214 filed Mar. 5, 1976, now U.S. Pat. No. 4,035,133.A fuel flow set point signal is delivered to a diaphragm motor valve to set a desired fuel flow-area therein; and, a differential pressure regulator maintains a correspondingly desired pressure drop thereacross.In a sonic flow embodiment regulator steam flow is controlled by a differential pressure regulator having its low pressure side connected to a ratio control device and its high pressure side connected to a downstream point in the steam line.

Abstract: At least two gas streams are passed into a surge vessel. The flow rate of a first one of the gas streams is manipulated responsive to either the deviations of the pressure in the surge vessel from a first pressure value or the deviations of the flow rate from a set value, depending on which would provide the larger flow rate. The flow rate of a second stream is manipulated responsive to deviations of the pressure in the surge vessel from a second pressure value which is higher than the first pressure value. The system is particularly applicable to the selective use of in-plant produced fuel gas, natural gas and liquefied petroleum gas to supply fuel gas demands in a plant, with the natural gas stream and the propane stream being the first and second streams, respectively.

Abstract: A control apparatus for a fanned, gaseous fuel-burning appliance, such as a water boiler for a domestic central heating system; the control apparatus includes electrical circuitry comprising first and second changeover switches each having a normally-closed pair of contacts and a third, normally-open contact, and a third switch; the switches are connected in a particular way to actuate gas valves and the fan of the appliance in a manner which provides improved safety features.

Abstract: A device for the setting and automatic regulation of the mixture ratio of a gas/air mixture for industrial furnaces comprises two coaxially-arranged diaphragm pressure gauges, connected in opposition, via a ratio setting mechanism, for the gas and the air, and a throttle member, controlled by the diaphragm displacement, in the gas or the air feed pipe. The two diaphragm pressure meters each are oppositely acted upon on only one side by the gas pressure or the air pressure respectively. The throttle member is controlled directly by the diaphragms. The diaphragm pressure gauges and the ratio setting mechanism together with the throttle member are designed as a structural unit.

Abstract: A system for burning two fuels in a burner wherein the second fuel is available in varying amounts. In response to the sensing of the available supply of the second fuel and the sensing of the total fuel required to be supplied to the burner, the system proportions the total fuel supplied to the burner between the first and second fuels to use as much of the second fuel as the supply will permit to meet the total fuel requirement. In addition, the system cuts off the supply of the first fuel to the burner when the available supply of the second fuel is adequate to meet the total fuel requirement and turns on the supply of the first fuel when the available supply of the second fuel is not adequate to meet the total fuel requirement.

Abstract: Apparatus for burning a product gas having a low BTU content wherein a single burner is adapted to burn the low energy gas alone with the turndown capability of a multi-burner arrangement. The gas flow is separated into two independent flow streams with one flow stream being exhausted into a primary air stream and the other into a secondary air stream prior to combustion. A common control means responsive to changes in load is provided to modulate the secondary air stream and its associated gas stream whereby at decreasing loads proportionately increased amounts of air and gas are directed through the primary air and gas streams.

Abstract: An improved method and apparatus are described for burning gaseous or vaporizable fuels, such as kerosene or other light fuel oils or gases. The burner provides for an efficient and complete burning of the fuel in a small combustion space and at variable rates. The burner utilizes a rotating fan to form a spiral or helical air flow within the combustion chamber. An interconnected rotating fuel nozzle for spraying the fuel into the spiral air path may be used or a stationary nozzle directing the fuel toward the fan. This provides for a long residence time of the fuel and air mixture providing a complete combustion of the mixture within the relatively small volume of the combustion chamber.

Abstract: The method for heating the furnace chamber produces high momentum levels during the heat treating cycle so as to obtain substantially uniform temperature throughout the charge. The method includes initially firing a plurality of high velocity burners at substantially maximum fuel input and in substantially stoichiometric ratio. Thereafter, the fuel input is reduced while maintaining the stoichiometric ratio at least during the high input portion of the cycle. Excess air is introduced external of the combustion zones of the burners on a predetermined signal such as a given fuel input reduction to maintain the desired momentum level within the furnace. The apparatus comprises a high velocity burner having associated therewith an excess air unit for discharging excess air external of the combustion chamber or port block of the burner.

Abstract: A process for the production of reducing gases and apparatus for use therein is provided. A unique gas mixer and reactor is provided which can be used to effect substoichiometric reactions of gaseous reactants to produce a hydrogen rich gas. The gases which are to be reduced are then admixed with the hydrogen rich gas and the gaseous mixture is passed to a catalytic reactor where the reduction reaction takes place.

Abstract: Apparatus controlling a plurality of fuels of different heat contents to a fluid heater burner including valves for selectively connecting the fuels to the burner and pressure responsive fuel flow regulators responding to the combined fuel/air pressure at the fuel burner to provide a given level of output for the boiler.

Abstract: A method of independently adjusting the fuel mixture composition and heating rate for a multiburner shaft furnace for the melting of metal, particularly copper and its alloys, fed in lump form to the shaft furnace, in which the burners are supplied with air and fuel gas and the heating rate is adjusted by controlling the pressure of one of the components of the fuel mixture (air or gas) in the manifold for supplying this component to a group of burners. The other fuel mixture component has its pressure controlled in its manifold by a single controller constituted by a pressure ratio controller.

Abstract: A real time monitoring and control system for single or multi-fired combustion systems which permits adjustment of the air fuel ratio in the system for optimized efficiency and minimized pollution content in the exhaust gas, while providing safety control of the combustion process. The system includes a high sensitivity light sensor which is utilized to monitor the combustion flame and provide an electrical output proportional to flame temperature, that is utilized to control the air fuel ratio of the system. The wavelength sensitivity of the sensor is capable of selection, for example by selection of sensor type and/or use of appropriate filters, to monitor a predetermined range or region of the flame emission spectrum in order to enable correlation of the intensity of the emission spectrum of the type of fuel being utilized, i.e., oil or natural gas, with temperature and combustion efficiency.

Abstract: A process for optimizing the combustion of fuel in a furnace wherein the total weight of carbon and hydrogen in the fuel is determined and from the total weight of hydrogen and carbon the air required for combustion can be computed with the air flow to the furnace being adjusted to provide the combustion air plus the desired excess oxygen. The efficiency of the furnace versus excess oxygen is determined and the excess oxygen is varied a small amount on each side of the optimum point obtained from the efficiency versus excess oxygen determination to continuously verify the optimum point.

Abstract: An electronic fuel injection system for maintaining absolute control over the air to fuel ratio flowing to the combustion chambers of an internal combustion engine. The system includes means for measuring the air flow rate to the engine. The flow rate measurement is converted into a proportional electrical signal which flows to a signal summing unit.The fuel flow rate from a fuel pump is controlled by a signal recieved from the signal summing unit, and provides a controlled fuel flow to the engine which is proportional to the air flow. Means associated with the fuel pump measures the exact flow rate therefrom and converts the measurement into another proportional electrical signal which is fed back to the summing unit to thereby form a closed loop circuit. The summing unit compares the first signal with the second signal and changes the fuel flow rate the required amount to maintain the ratio thereof at a predetermined value.

Abstract: A furnace containing a burner, supplied by fuel to be ignited at the burner, in the presence of air, is provided with a viewing duct for viewing the flame and means for detecting the radiation intensity at a plurality of different wavelengths of the radiation spectrum. The output from the detector is amplified and integrated and a signal representing the ratio of intensities at the selected wavelengths is applied to an indicator to indicate fuel-air ratio and also is applied to control means for the fuel flow or the air flow, or both, to control the fuel-air ratio at the burner and to maintain it substantially constant at a desired value. This can be done at more than one burner, providing balanced furnace operation. With this balanced furnace, there is improved firing efficiency, resulting in fuel saving and lowered pollution emissions. A computer type master controller can be used to correlate the fuel-air ratios for the individual burners.

Abstract: A combustion control system is operated based on the detection of smoke density. A photoelectric device measures the intensity of light directed through the smoke by a lamp in order to measure the smoke density. This measurement is employed to control fuel and/or air supply or the like. To provide a standard reference, light is directed from the lamp through an alternate path not affected by the smoke to the photoelectric device. A shutter mechanism alternately exposes the photoelectric device to light passing through or circumventing the smoke. The photoelectric measurement is compared with a standard and the comparison is used to adjust circuitry connected to the photoelectric device to stabilize the effects of the latter. A continuous monitoring of the adjustment is carried out to determine when an acceptable range of adjustment has been exceeded. A smoke density amplifier is employed to increase effectiveness.

Abstract: A fuel supply system for a heat generator comprises means for spraying fuel into an air inlet tube, which means are branched off a fuel supply line supplied by a pump having a fuel delivery greater than the fuel comsumption rate of the generator. The fuel line extends to a constant-level chamber by way of a variable-opening throttle element controlled in dependence upon the air flow through the inlet tube, the pump intake being connected to the constant-level chamber. A bypass circuit is adapted to connect the fuel pump output to a fuel reservoir and is closed by a calibrated valve which opens in response to a predetermined fuel pump delivery rate so that the fuel in the constant-level chamber is renewed when the rate of generator fuel comsumption is low.

Abstract: A method and at least one gas flare for carrying out or practicing the method are disclosed for smokeless burning of undesired gas. Combined with a steam aspirating gas flare having a steam flow controller responsive to a gas flow detector to provide a combustible material is a specific gravity analyzer for controlling the steam flow controller further in relation to the specific gravity of the gas to be burned for providing a smokeless air-to-gas burning mixture in the flare with less steam usage and reduced noise.