Abstract: Raw gas burner that maximizes fuel efficiency of the burner, minimizes residence time, and reduces or eliminates flame contact with the process air or gas in order to minimize NOx formation. Process air flow such as from the cold side of a heat exchanger associated with thermal oxidizer apparatus is directed into and around the burner. The amount of process air flowing into the burner is regulated based upon the pressure drop created by the burner assembly. The pressure drop is, in turn, regulated by one or more of an external damper assembly, an internal damper assembly, and movement of the burner relative to the apparatus in which it is mounted. To ensure thorough mixing of the fuel and process air, process air entering the burner is caused to spin by the use of a swirl generator. The fuel/process air mixture proceeds into the combustion section of the burner, where the swirling flow is caused to recirculate to ensure complete combustion of the fuel in the combustion chamber.

Abstract: A compact gas-fired radiant space heater is adapted for residential use, having an output in the 20k BTU to 40k BTU/hr range and exterior dimensions small enough to allow it to be installed in a standard two foot by four foot suspended ceiling opening. A radiator tube having a total length of approximately 15 feet is bent into a serpentine shape, and combustion control components are housed within a plenum chamber supplying combustion air to the tube, both the tube and the chamber being encircled by a frame that fits within the two foot by four foot opening. The combustion control components are attached to a chassis plate whereby the components are removable from the plenum chamber as a unit to enhance serviceability of the heater. A burner venturi of novel configuration produces a flame that is less than four feet long yet which is relatively quiet.

Abstract: In a two-stage furnace system, including a thermostat, at least one gas burner with a low and high-fire operating capability, an inducer fan having low and high speed operating settings, and a high-fire pressure switch, a method for handling the high-fire pressure switch being in an inappropriately open condition. The method has the steps of: determining whether the thermostat is issuing a call for high heat and, if it is, determining if the high-fire pressure switch is open. If the high-fire pressure switch is open, waiting a predetermined time, determining if the high-fire pressure switch is still open and, if it is, completing a furnace shutdown procedure, then initiating a normal shutdown, then an ignition sequence in high-speed inducer pre-purge mode, determining if the high-fire pressure switch remains open, and if so, running at least one gas burner in low-fire mode. If, while these steps are being performed, the high-fire pressure switch closes, running the system in high-fire mode.

Abstract: The present invention relates to an intelligent transient eliminator which allows a gas ignition system to prevent gas valves from being turned off by a pressure switch in response to a transient pressure wave. The transient eliminator is preferably provided in a HVAC unit or furnace which burns a fuel such as natural gas. An ignition control system employing an intelligent transient eliminator provides a secondary relay across the pressure switch. The secondary relay is controlled by a signal to an ignitor in the furnace. The secondary switch is tested before energizing the inducer blower in the system.

Abstract: A coffee bean roasting device for roasting coffee beans by applying hot air to the coffee beans. The coffee bean roasting device includes a detector for detecting a factor exerting influence upon the roasting state of coffee beans, and a controller for controlling the hot air supplier and/or exhaust discharger in accordance with a detection signal input from the discharger. The controller may be, for example, an electronic control portion such as computer including a pressure sensor for detecting a pressure value of the roasting space as a factor exerting influence upon the roasting state of coffee beans and adapted to record a pressure value input from the pressure sensor in a particular roasting state of coffee beans as a particular pressure value and control the exhaust discharger to regulate the amount of exhaust gas on a basis of the pressure value input from the pressure sensor, such that the pressure value of the roasting space becomes such recorded particular pressure value as a target value.

Abstract: A method of controlling the pressure in an incinerator for incinerating municipal refuse, industrial waste, etc. Exhaust gas from an incinerator typically passes through an exhaust gas cooler and an exhaust gas treating device and then discharged into the atmosphere by the action of an induced draft fan. In a method of controlling the pressure in such an incinerator for incinerating municipal refuse, industrial waste, etc. gas, e.g., part of the flow of exhaust gas induced by the induced draft fan or air taken in from the atmosphere, is added to a gas flow path upstream of the inlet of the induced draft fan through an addition gas line provided with an addition gas control damper. The addition gas control damper is controlled on the basis of an output from a furnace pressure controller such that when the furnace pressure is relatively high, the flow rate of the addition gas is reduced, whereas, when the furnace pressure is relatively low, the flow rate of the addition gas is increased.

Abstract: A fuel pressure regulator controls the pressure differential across a nozzle which is subject to variations in exhaust gas backpressure having a solenoid actuated valve member which is actuable in response to signals from a controller to establish a predetermined fuel pressure across the nozzle consistent with a control strategy. A pressure dependent valve actuator is operable on the valve member, independently of the solenoid, to adjust the valve opening and, as such, the fuel pressure at the nozzle to adjust the fuel pressure in response to exhaust gas.

Abstract: The present invention discloses a two stage furnace control. The control includes a gas valve, an ignitor, a low pressure switch, a high pressure switch and a control unit for enabling the inducer fan, the circulator fan, the ignitor, and the gas valve. The gas valve is coupled in series with the low pressure switch, the high pressure switch, and the power source whereby the low and high pressure switches directly control supply of electric power to the gas valve.

Abstract: A fuel-fired, forced draft heating appliance includes a draft inducer fan having an inlet connected to a vent hood, an outlet connectable to a vent pipe, and an interior housing region in which a negative pressure is generated during normal appliance operation. The vent hood receives hot combustion gases generated by the appliance, and has an inlet for receiving ambient dilution air that mixes with and cools the combustion gases entering the hood and subsequently discharged into the vent pipe by the fan. A combination pressure and temperature limit control is used to sense the presence of an obstruction in either the vent pipe or the vent hood inlet and responsively shut down the appliance. The control includes a vacuum switch external to the fan, a bimetallic disc-type temperature sensor disposed within the negative pressure fan region, and a conduit interconnecting the switch and the temperature sensor.

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: An ignition control apparatus for a pulse combustor, wherein the number of trials for energization of a spark electrode is calculated and memorized, the memorized number of trials is reset to an initial value or zero after ignition of the fuel-air mixture in a combustion chamber of the combustor has been successfully obtained, a period of time for pre-purge of the combustion chamber is determined in accordance with the memorized number of trials for energization of the spark electrode, and a purge blower for the combustor activated for the determined period of time prior to energization of the spark electrode to change the unburned mixture ratio to a non-combustible ratio on the trial for ignition. In the ignition control apparatus, the presence of flame in the combustion chamber is further detected for a predetermined time, and the purge blower is deactivated when a predetermined number of trials for ignition have been attempted due to lack of the presence of flame in the combustion chamber.

Abstract: The present invention involves a two stage furnace and a method of controlling the fans. In the furnace, a high pressure switch indicates whether sufficient air is present to support high combustion. Normally the furnace operates at one of the combustion settings. The circulator fan operates at the high speed setting when the high pressure switch indicates that sufficient air is present for high combustion, and operates at the low speed setting when the high pressure switch indicates that insufficient air is present for high combustion.

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: The present invention discloses a method of compensating for a restricted intake in a two stage furnace. The furnace includes low and high pressure switches for determining if sufficient air is present to support low and high combustion. When the furnace operates at high combustion, the state of the high pressure switch is monitored to determine if the high pressure switch has changed state for a predetermined amount of time such as 15 seconds. The inducer fan is switched to low when insufficient air for high combustion has been indicated for such a predetermined time. If the state of the low pressure switch indicates that insufficient air is available for low combustion, then the inducer is turned on high.

Abstract: A reverse flow prevention device for combustion apparatuses control operated by electrical power, and which is provided with a combustion gas discharge tube for discharging the combustion process by-product. The reverse flow device comprising a reverse flow gas collecting tube installed within the combustion gas discharge tube for collecting reverse flow gas. The reverse flow device also comprises a detection means, with a function of detecting a reverse flow gas and turning OFF the combustion apparatus when the pressure of the reverse flow gas acting on the detection means is above a certain level.

Abstract: A forced draft direct vent system is provided for an indoor domestic type gas water heater having an atmospheric burner. The forced draft system permits adaptation of the water heater as a combined water heater and space heater in a compact continuous upright arrangement of components.

Abstract: An improved steady state fuel burner assembly and method of operation for a space heater wherein fuel and combustion air are initially ignited within a burner assembly with the resulting higher pressure in the burner assembly causing throttling of combustion air into the burner assembly until a preselected lower pressure is reached compatible with steady state combustion through exhaustion of initially combusted gases.

Abstract: The invention relates to an afterburner apparatus and an incineration system and methods of waste destruction in primary incineration combustion means and afterburner means which both preferably utilize at least two different oxidizing gases. By varying the ratio of said oxidizing gases, the amount of total oxygen and nitrogen delivered in either means can be dynamically adjusted in accordance with the process requirements. Varying the flows of at least two oxydizing gases and auxiliary fuel in both the primary incinerator and afterburner makes it possible to operate the system under fluctuating waste loading conditions, by controlling temperature, partial pressure of oxygen and heat available for the process as a function of said ratio.

Abstract: An integrated electronic control arrangement is disclosed in the illustrative environment of burner such as in a gas-fired furnace. The control incorporates a self-test feature which shuts down the furnace in the event of any one of a number of possible sensed faults. Self-testing occurs automatically before an attempt at ignition and during furnace operation. Proper functioning of the sensor which senses for induced air flow through the burner combustion chamber is tested prior to enabling a fan which causes that induced air flow. Air flow is confirmed by sending to and receiving back from the sensor a sequence of pulses. Should air flow not be sensed during a combustion period, combustion is terminated. A flame sensor is provided for determining the presence of a flame in the combustion chamber. During times when a flame should be present, pulse sequences are sent to and received back from the flame sensor to confirm that a flame is present.

Abstract: A refractory flame-gunning apparatus has a feeder, a controller and a flame-gunning burner. The feeder has a refractory-powder feeding section, an inflammable-gas feeding section and a combustion-assisting-gas feeding section. The controller controls the supply of refractory powder, inflammable and combustion-assisting gases. The flame-gunning burner has a plurality of refractory powder and flame ejecting nozzles disposed at its tip. The flame-gunning burner has a gas mixer and a combustion-assisting-gas cutoff valve. The gas mixer has an inflammable-gas passage leading to the inflammable-gas feeding section, a combustion-assisting-gas passage leading to the combustion-assisting-gas feeding section, a gas mixing chamber communicating with the inflammable and combustion-assisting gas passages, and a mixed-gas passage the upstream side of which communicates with the gas mixing chamber and the downstream side of which communicates with the flame ejecting nozzles.

Abstract: A multi-pass ceramic recuperator includes a temperature compensator mounted within the gaseous flow of an intermediate pass. The compensator includes a bleed valve actuated by a temperature sensitive mechanism which is mounted outside the compensator body and directly in the gaseous flow.

Abstract: A flame detecting apparatus used in a combustion control apparatus for a water heater provided with a gas burner comprises a pressure switch serving as means for detecting presence or absence of flame and a voltage comparison circuit serving as means for determining the presence or absence of the flame on the basis of the input signal supplied by the pressure switch. The voltage comparison circuit has an offset voltage and has a non-inverting input terminal connected only to the ground.

Abstract: An ignition system for a furnace or boiler where a predetermined number of firing pulses are generated between timing intervals to allow purging of the combustion chamber. If combustion occurs, the firing pulses are terminated. If combustion does not occur, after the predetermined number of firing pulses, the combustion chamber is purged and the system shut down.

Abstract: A gas burner which consists of a cylindrical duct forming member closed at one end and open at the other end to receive a gas/air mixture under pressure. The member is perforated so that the gas/air mixture flows to the outside of the member where it is burned. The duct is provided with a cone-shaped plug for reducing the volume of the duct from the open end towards the closed end so that a constant velocity of gas/air mixture is maintained within the duct to obtain a uniform static pressure on the outside in the region where the gas/air mixture is burned.

Abstract: A fuel and ignition control for a pulse combustion furnace includes both analog and digital timing means for fail safe operation, fuel valve control means which depend on proper cyclic operation for proper function, and flame detection means which are fail safe due to the necessity of its components providing a critical phase shift angle. The fuel control valve means includes energy storage means which is stepwise depleted to positively limit the time of valve energization in the absence of detection of flame, and is also disabled after a predetermined time by the digital timing means.

Abstract: A flame rod inserted in a flame created by the secondary air supplied to a burner is used to generate a flame signal voltage. This flame signal voltage fluctuates with the amount of secondary air available and with the fuel supplied. These fluctuations are relied upon by an integrated control system that utilizes a microprocessor or microcomputer to safely control an induced draft-type of furnace.

Abstract: The tube-fired radiant heating system is of the type where an elongated tube is heated by hot gases of combustion which are passed. The heated tube radiates heat to the space to be heated therethrough.A burner is provided at one end of the tube to burn an air/fuel mixture. The products of combustion are forced through the tube by means of a blower provided at the tube inlet. Burning takes place within the tube. A tubular stream of air is constantly passed over the flame to protect the tube from the high heat of combustion.

Abstract: A porous ceramic heating reactor is positioned within a tubular casing to contain the flame and the end products of combustion. A flattened portion of the casing extends substantially past the reactor to provide for further transfer of heat through the casing wall from the hot exhaust gases and to carry those exhaust gases to a safe point of exhaustion. The unit is essentially modular so that any number can be selected for an installation. The casing configuration enhances turbulent flow of the hot gaseous products of combustion. Turbulent flow increases heat transfer to and through the walls of the casing to the boilder or other area to be heated. The size and shape of the tubular casing provides an explosion proof, leak proof, efficient heat transfer device. Each reactor has a spark plug one of whose elements is a bi-metallic strip. In a multi-unit installation the spark plugs are connected in parallel across a spark generator.

Abstract: A safety device for a gas burner comprises a first ignition nozzle 31 in a pilot burner 3, an inflammable gas guide tube 32 facing the first ignition nozzle, a second ignition nozzle 33 at the end of the guide tube oriented toward a main burner 2, a pressure sensing tube 6 coupled between the guide tube portion near the first ignition nozzle and one diaphragm chamber of a differential pressure sensing device 7, and an automatic valve 4 actuated by the pressure sensing device to close a main gas pipe 1. If the flame at the first ignition nozzle is extinguished the pressure near the beginning of the guide tube increases sharply, which actuates the pressure sensing device 7 to close the valve 4 and terminate combustion.

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: An automatic damper control comprising: damper means for use in a flue or the like; diaphragm means adapted to expand and contract in response to pressure variations in the flue; and sensor means for sensing the pressure in the flue. The sensor means is connected to the diaphragm means and comprises means for generating a plurality of beams of light. The sensor means further comprises collimating means adapted to collimate each of the beams of light onto a photoreceptor. The damper control also comprises blocking means for blocking at least one of the beams of light. The blocking means is operatively associated with the diaphragm means and is adapted to be displaced relative to the beams of light in response to movement by the diaphragm means. Drive means are additionally provided for moving the damper means in response to pressure variations in the flue.

Abstract: This invention relates to a furnace equipped with a fuel optimizer for more effectively controlling fuel consumption in the furnace and a method for using the furnace fuel optimizer. In particular, the invention relates to a furnace fuel optimizer which controls combustion air by maximizing radiant section heat transfer with respect to convective section heat transfer while monitoring CO emissions in the flue gas and monitoring the draft below the convective section in order to obtain an optimum control value. The furnace fuel optimizer then regulates the furnace to correspond to the optimum control value by adjusting the air input to the furnace so that continuous furnace operation is possible at maximum efficiency.

Abstract: A fuel supply system for use in a fluid bed furnace or the like of the type which includes a bed comprising a quantity of particles, which bed fluidizes in response to the flow of heated gases upwardly therethrough and a burner for burning a supplied fuel and providing the fluid bed with a sufficient gas mixture flow at an elevated temperature for heating and fluidizing the fluid bed.

Abstract: An improved fluid bed furnace which includes a new and improved pilot light assembly and which is of the type having a fluid bed comprising material which fluidizes upon being subjected to a flow of gas mixture therethrough and a burner for burning a fuel mixture for providing the flow of gas mixture at an elevated temperature through the fluid bed material for fluidizing and agitating the fluid bed material. The pilot light assembly includes an ignition means for providing a pilot flame, pilot flame confining means for directing the pilot flame into the furnace fluid bed above the fluidizable material for causing the pilot flame to ignite the burner fuel mixture, and pilot flame detecting means for sensing the presence of the pilot flame and enabling the supply of the fuel mixture to the burner.

Abstract: A sleeve and damper to increase the efficiency of oil burner performance designed to substantially enclose the flame. The sleeve is heated by the flame to a temperature sufficiently high to assure automatic ignition of unburned hydrocarbons that may result from incomplete combustion of the fuel oil. By controlling the damper operation in conjunction with an adjustable induction air apparatus, unburned hydrocarbons which would ordinarily result are completely oxidized. The resulting completeness of combustion permits the use of oil as a fuel to heat ovens without imparting any odor or taste to the food products being processed therewithin.

Abstract: In using a gas torch it is often necessary to maintain a uniform flame. This can be accomplished by maintaining a constant pressure at the torch tip. A pressure transducer is placed at the output of a generator that produces gas by electrolysis for the torch. The transducer indicates changes in the gas pressure by changing resistance. The transducer is coupled to a resistance-capacitance circuit and forms a variable part of the resistance of the circuit. This circuit, in turn, is coupled to the firing gate of a triac which controls the rate of gas disassociation of the electrolytic solution in the gas generator by varying the amount of current fed to the gas generator. When the pressure at the output of the generator varies, the resistance of the pressure transducer changes thereby changing the RC time constant of the resistance-capacitance circuit. Such a change modifies the firing rate of the triac and, therefore, the rate of gas generation and pressure.

Abstract: In a fired furnace system having a convection section, and in which control a furnace draft is vital to both fuel conservation and avoidance of furnace damage, apparatus for monitoring the pressure conditions (draft) inside the furnace comprises a first pressure sensor means positioned at the arch (roof) of the furnace, a second pressure sensor means inside the furnace downstream from the convection section, and differential pressure measuring means connected between the first and second means for constantly measuring the pressure drop through the convection section.

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: There is disclosed a safety control for a pulse combustion system. In a pulse combustion process, a combustible fuel and air are introduced into a combustion chamber through check valves in pulses and ignite to generate an alternating sinusoidal pressure wave. The control system of the invention comprises rectifying the sinusoidal pressure wave to obtain therefrom a differential pressure signal and applying the pressure signal to a control circuit to position a valve in the combustible fuel supply. Any interruption in combustion within the chamber causes a cessation of the differential pressure signal and closes the control valve.

Abstract: A liquid or gaseous (fluid) combustible is mixed with a combustion-sustaining gas and fed under pressure into a chamber where the mixture is burned. The mass flow of the combustible (fuel) is normally maintained constant for a combustion chamber of given thermal power output. The pressure in the chamber is continuously detected and the ratio of the mass flow of recirculated exhaust gas to the mass flow of the oxygen-containing gas (air or oxygen), which together constitute the combustion-sustaining gas, is increased when this pressure increases above a predetermined limit and the ratio is decreased when the pressure decreases below a predetermined limit. The ratio is varied by increasing or decreasing the proportion of exhaust gases and thereby decreasing or increasing, respectively, the partial pressure of oxygen in this combustion-sustaining gas.

Abstract: The invention relates to an afterburner apparatus and an incineration system and methods of waste destruction in primary incineration combustion means and afterburner means which both preferably utilize at least two different oxidizing gases. By varying the ratio of said oxidizing gases, the amount of total oxygen and nitrogen delivered in either means can be dynamically adjusted in accordance with the process requirements. Varying the flows of at least two oxydizing gases and auxiliary fuel in both the primary incinerator and afterburner makes it possible to operate the system under fluctuating waste loading conditions, by controlling temperature, partial pressure of oxygen and heat available for the process as a function of said ratio.