Abstract: A gas supply system for a flame module of a spectrometer and a method of controlling a flame module. The gas supply system comprises an oxidant gas supply line for providing a supply of oxidant gas, an oxidant gas flow valve for varying a gas flow rate of an oxidant gas in the oxidant gas supply line, an oxidant gas safety controller configured to control the oxidant gas flow valve, a fuel gas supply line for providing a supply of fuel gas, a fuel gas flow valve configured to control a gas flow rate of a fuel gas on the fuel gas supply line, and a fuel gas safety controller configured to control the fuel gas flow valve. During normal operation, the oxidant gas safety controller is configured to charge an energy storage circuit of the oxidant gas safety controller.

Abstract: A device that includes a pressure sensor that adds dynamic pressure sensing capability to a furnace. In some examples the device may include a relay and other circuitry to replace the single-setpoint pressure switch used to sense the operation of an inducer fan. The pressure sensor may measure the pressure from the inducer fan and send a signal to the other circuitry, such as a microcontroller. The other circuitry may determine when the pressure from the inducer fan reaches a predetermined threshold and allow the main gas valve of the furnace to open. The other circuitry may be configured to set the pressure sensor to a variety of predetermined pressure thresholds, and thereby replace multiple pressure switches. In some examples, the other circuitry may record pressure values received from the pressure sensor over time and provide performance data, as well as other signals or indicators.

Abstract: Example furnaces and methods related thereto include a burner box including at least one burner configured to combust a fuel/air mixture. In addition, the furnace includes a first blower including an inlet nozzle having an air inlet and fuel inlet. The inlet nozzle is configured such that operation of the first blower is to pull air and fuel into the inlet nozzle to produce the fuel/air mixture at a fuel/air ratio that is configured to produce flue products having less than 14 Nano-grams per Joule of nitrogen oxides when combusted. Operation of the first blower is configured to push the fuel/air mixture into the burner box. Further, the furnace includes a heat exchanger assembly fluidly coupled to the burner box through a vestibule, and a second blower configured to pull the flue products through the heat exchanger assembly.

Abstract: A system and method for controlling a porous medium burner of medium-high temperature heating field, the control system includes a local control system and a remote control system; the local control system is configured for acquisition and feedback of data, and execution of an action; and the remote control system communicates with the local control system in real time and is configured for storage and analysis of data and transmission of an instruction. A system and method for controlling a porous medium burner of medium-high temperature heating field, which can effectively perform prediction and prevention of flashback, be adapted to combustion of gases with different calorific values, monitor and diagnose, in real time, a usage status of a porous medium material, and be suitable for the functions such as real-time monitoring of preheating of air and a fuel gas.

Abstract: This disclosure relates generally to valves, and more particularly, to gas valve assemblies. In one example, the valve assembly may include a valve body with an inlet port, an outlet port, and a fluid path extending between the inlet and outlet ports, one or more valves situated about the fluid path, one or more valve actuators for selectively moving respective valves, one or more sensors for sensing one or more parameters within the fluid path, and a controller secured relative to the valve body and in communication with the one or more sensors for determining one or more valve assembly conditions based on the one or more sensed parameters. Illustratively, the controller may be configured to communicate information from the valve assembly to a combustion appliance controller that is located remotely from the valve assembly through a communications interface of the controller and across a communications bus.

Abstract: A device for mixing combustible gas and combustion air, hot water installation, and corresponding thermal mass flow sensor and method. The device includes an air line, a gas line with a control valve, a first measuring line connecting the air and gas lines, and a second measuring line connecting the first measuring line to the gas and/or air line, forming a three-way intersection. A thermal mass flow sensor includes first and second temperature sensors in the first measuring line, positioned respectively in a gas flow between the three-way intersection and the air line and in a gas flow between the three-way intersection and the gas line. A controller controls the control valve based on a difference, measured by the flow sensor, between mass flow rate of gas between the three-way intersection and the air line and mass flow rate of gas between the three-way intersection and the gas line.

Abstract: A system for verifying operation of a contact includes a voltage source connected to a first terminal of the contact through a first switch; a second switch connected to a second terminal of the contact; a third switch connected to the second terminal of the contact; a voltage output connected to the second switch and the third switch; and a controller to compare the voltage output to a first voltage and a second voltage; wherein the voltage output indicates operation of the contact in response to status of the first switch, the switch and the third switch.

Abstract: A flame sense circuit and method utilizing only a single pin of a microcontroller is provided. A flame sense circuit is used to vary the charge on a capacitor from a logic high indicating no flame to a logic low when a flame is detected. The microcontroller changes the state of the pin coupled to this circuitry from a high impedance input to detect when the capacitor is discharged indicating the presence of flame, to a logic high output to recharge the flame sense capacitor. Once this charging has been accomplished, the microcontroller again changes the status of the pin to a high impedance input and verifies that the capacitor has been charged. This pin is monitored to verify that the flame sense capacitor is again discharged to indicate the continued presence of flame. This process is repeated to ensure flame continues to be present during a combustion event.

Abstract: A drying system (100) for use in drying out a water-damaged structure includes a blower (105) for providing outside air to the water damaged structure. An indirectly fired furnace (101) is used for heating the outside air prior to its introduction into the water-damaged structure. An exhaust blower (114) removes humid air from the water-damaged building, and one or more remote temperature and humidity sensors (117) are used for controlling the furnace air temperature and supply blower volume. An air intake filter box (111) is used for adding make-up air to recirculated building air and promoting cooling within accompanying trailer. A differential air pressure transmitter (118) controls the volume of moist air removed from the water damaged building to an optimal rate.

Abstract: Disclosed is a combustion apparatus using an air fuel ratio sensor, which detects the operation of the air fuel sensor based on pressure of gas and air introduced into a combustion chamber and adjusts the amount of gas and air introduced into the combustion chamber using a controller based on data detected by the air fuel sensor.

Abstract: The present invention provides a system and method for injecting natural gas in an RTO. The RTO may be, for example, a known type that has a rotary distributor, a center section divided into pie-shaped segments above the rotary distributor, a heat exchanger section above the center section, and a combustion chamber above the heat exchanger. According to an aspect of the invention, the system introduces gas into segments of the center section in a sequenced manner via cycling on/off control valves. In a particular embodiment, the natural gas is injected at a specific location of a respective segment within the center section that is past the rotary distributor seals and directly under the bottom of the heat exchanger bed. According to the injection sequence, the injection of natural gas into the segment commences when the segment begins to receive inlet waste gas streams, and injection ceases before the flow through the sector changes or stops.

Abstract: Provided is a combustion apparatus that can positively prevent a combustible gas present in the vicinity from catching fire in performing prepurge, which involves exhausting air from a combustion chamber provided with a burner, before igniting the burner. The combustion apparatus 1 contains combustion control means 6 that ignites the burner after performing prepurge by use of a fan 4, and gas detection means 5 that is provided between an air supply port 7 and the fan 4 and detects the concentration of a combustible gas. The combustion control means 6 ascertains, before starting the prepurge, whether a combustible gas of a preset maximum concentration or higher is detected by use of the gas detection means 5 (STEP 1) and prohibits the prepurge by prohibiting the energization of the fan 4 when a combustible gas of the maximum concentration or higher has been detected (STEP 2).

Abstract: Provided is a combustion apparatus that can positively prevent a combustible gas present in the vicinity from catching fire in performing prepurge, which involves exhausting air from a combustion chamber provided with a burner, before igniting the burner. The combustion apparatus 1 contains combustion control means 6 that ignites the burner after performing prepurge by use of a fan 4, and gas detection means 5 that is provided between an air supply port 7 and the fan 4 and detects the concentration of a combustible gas. The combustion control means 6 ascertains, before starting the prepurge, whether a combustible gas of a preset maximum concentration or higher is detected by use of the gas detection means 5 (STEP 1) and prohibits the prepurge by prohibiting the energization of the fan 4 when a combustible gas of the maximum concentration or higher has been detected (STEP 2).

Abstract: An intelligent burner control apparatus is provided for controlling the rate of air and fuel flow in a burner system from air and fuel supplies to a burner. The apparatus includes a peer-to-peer communication network including a plurality of network control modules that communicate with each other over the communication network. The apparatus further includes a brain module including one of said network control modules coupled to the communication network, air and fuel flow controllers including one of said network control modules coupled to the communication network, and air and fuel flow regulators including one of said network control modules coupled to the communication network. The brain module is configured to send air and fuel setpoint signals over the communication network to the air and fuel flow controllers.

Abstract: A method for controlling an igniting operation for a gas boiler for preventing an explosive ignition is disclosed. The gas boiler is equipped with a burner for burning a gas, a fan for exhausting a burnt gas in the burner, and an ignition plug for performing igniting operation of the gas supplied into the burner. If the operation of the gas boiler commences, the gas is supplied into the burner while the exhaust fan is operated at a low speed appropriate for performing the igniting operation, and the ignition plug is operated to perform the igniting operation of the gas in the burner. In that situation, if ignition does not occur during a predetermined time, the rotational velocity of the exhaust fan increases, whereby the density of gas in the burner is maintained constant. Thus, the excessive increasing of the gas density is prevented, so the explosive ignition is prevented.

Abstract: An integrated burner system is disclosed having a fuel supply assembly including a fuel control for variably limiting the flow of fuel into the burner along with a discrete air control for generating a variable flow of air into the burner. The respective fuel and air controls are directed by a control system which operates these controls in order to provide and maintain a desired fuel-to-air ratio between high fire and low fire in response to a requirement for heat. A multiple burner embodiment is disclosed in which a plurality of the present integrated burners may be used to create a multiple burner system which provides a greater degree of control and efficiency than that capable with previous systems. The multiple burner embodiment also eliminates the costly installation and maintenance requirements typically associated with previous systems.

Abstract: A combustion of the present invention has a burner, a combustion fan supplying air to the burner, revolution rate detection means for detecting a revolution rate of the fan, and an air-flow rate sensor for detecting an air-flow rate of the air. The combustion device further has a temperature sensor for detecting a temperature at the combustion device and diagnosis means for performing a self-diagnosis to determine a ventilation condition based on a relationship between the revolution rate and the air-flow rate. The diagnostic means correct the detected revolution rate or the air-flow rate based on the temperature of the combustion device in the process of performing the self-diagnosis. The diagnosis means perform the self-diagnosis after a predetermined time has passed until there is no temperature variance in the combustion device since a combustion halts.

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: An electric control system for a pulse combustion device of the type which includes a combustion chamber mounted within a liquid vessel of a liquid heating apparatus, fuel and air inlet valves arranged to supply a mixture of fuel and air into the combustion chamber, a tailpipe connected at one end thereof to an exhaust port of the combustion chamber to take place therein resonant combustion of the mixture of fuel and air and immersed in an amount of liquid stored in the vessel, and an electrically operated air intake blower arranged to supply fresh air into the combustion chamber through the air inlet valve.

Abstract: According to this invention there is provided a process and apparatus for the ignition of a pilot burner in an inert atmosphere without substantially contaminating the inert atmosphere. The process includes the steps of providing a controlled amount of combustion air for a predetermined interval of time to the combustor then substantially simultaneously providing a controlled mixture of fuel and air to the pilot burner and to a flame generator. The controlled mixture of fuel and air to the flame generator is then periodically energized to produce a secondary flame. With the secondary flame the controlled mixture of fuel and air to the pilot burner and the combustion air is ignited to produce a pilot burner flame. The pilot burner flame is then used to ignited a mixture of main fuel and combustion air to produce a main burner flame.

Abstract: A burner control system with an interrupted or intermittent type of pilot burner has a special feature allowing transitions between a pilot flame hold state where the pilot flame only burns and the run state where the main burner is operating. Each transition to the pilot flame hold state from the run state comprises a brief period in which presence of the pilot flame is assured while the main flame is extinguished. Transitions to the run state from the pilot flame hold state may proceed directly through the main flame establishment period to the run state, thereby eliminating the time-consuming purging and pilot flame ignition phases.

Abstract: A heat exchanger system, a fuel control system therefor and methods of making the same are provided, the fuel control system having an electrical circuit means that comprises an ignition trial portion, a flame sensing control portion and a timer portion that comprises a counter having a plurality of outputs and a timer that clocks the output of the counter on each discharge of the timer, the timer portion also comprising a capacitor, a trial time resistor and a wait time resistor that are selectively placed in series with the capacitor by the counter when clocked to certain outputs by the timer to determine an ignition trial time period and a wait time period, and a transistor operatively interconnected to the capacitor to discharge the capacitor when flame is sensed by the flame sense portion.

Abstract: A heat exchanger system, a fuel control system therefor and methods of making the same are provided, the fuel control system having an electrical circuit means that comprises an ignition trial portion, a flame sensing control portion and a timer portion that comprises a counter having a plurality of outputs and a timer that clocks the output of the counter on each discharge of the timer, the timer portion also comprising a capacitor, a trial time resistor and a wait time resistor that are selectively placed in series with the capacitor by the counter when clocked to certain outputs by the timer to determine an ignition trial time period and a wait time period.

Abstract: A water heater includes a tank for receiving cold water and dispensing heated water. A thermostat is associated with the tank and detects the temperature of water held therein. A gas burner including a hot surface igniter receives fuel to be combusted via a fuel line when a valve on the fuel line is opened. A controller is responsive to the thermostat and opens the valve and operates the igniter to ignite the fuel when the temperature of the water held in the tank falls below a first predetermined level. A vent including a flue passes through the tank and allows combustion gases and heat of combustion to be vented from the water heater. The vent includes a blower responsive to the controller which mixes ambient air with combustion gases prior to venting the combustion gases to the atmosphere. The controller initiates the blower when the water temperature falls below the first predetermined level to establish at least a predetermined pressure in the flue before the valve and igniter are operated.

Abstract: An automated conveyorized oven includes a radiant heater assembly including a plurality of gas-fired radiant heaters positioned beneath the oven conveyor. Each heater assembly includes radiant heating elements in the form of perforate metallic plates, at the outer surface of which combustion takes place for elevating the temperature of the plates for generating radiant heat. Consistent and reliable operation is promoted by the provision of a control arrangement which acts to preclude flashback combustion upstream of the surface of the metallic heating elements, with the controls being operable to permit sufficient time for the heating elements to cool, after interruption of the gas supply thereto, before gas is resupplied to the heater units.

Abstract: A heat exchanger system, a fuel control system therefor and methods of making the same are provided, the fuel control system having an electrical circuit means that comprises an ignition trial portion, a flame sensing control portion and a timer portion that comprises a counter having a plurality of outputs and a timer that clocks the output of the counter on each discharge of the timer, the timer portion also comprising a capacitor, a trial time resistor and a wait time resistor that are selectively placed in series with the capacitor by the counter when clocked to certain outputs by the timer to determine an ignition trial time period and a wait time period.

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: Time-delay circuit for automatic shutdown of furnace systems has an induced draft blower motor and a first circuit for providing energy to the blower motor from an energy source. A second circuit for energizing the primary control system of the furnace, includes a thermostat and an electronic switching means. When the thermostat is "closed", the second circuit is completed to energize the electronic switching element which starts the blower. An airflow switch is provided to sense the start of the blower and to thereby energize a primary control which provides gas to a burner of the furnace. A timer set to a predetermined time interval has an output and two input terminal connections, one connected to the output of the thermostat and another to the output of the primary control system. When the thermostat is "closed" and the burner is operating, the timer is disabled.

Abstract: A burner system has a control system which operates to prevent startup of the burner if an airflow switch indicates presence of combustion air flow before startup of a blower which provides the air flow. If the airflow switch later indicates absence of air flow before startup, then startup can proceed normally without operator intervention. Power for startup is supplied through the normally closed contacts of a safety relay. The winding of the safety relay receives power through the airflow switch. When the airflow switch is closed the safety relay winding is energized, opening the normally closed safety relay contacts and thereby blocking burner system startup, but only unit the airflow switch opens.

Abstract: Provision is made for sensing when the gas valve relay contacts are welded, or stuck, in the closed position and for responsively turning off the inducer motor when that occurs. This in turn causes the pressure switch to open to thereby cut off the power to the gas valve and cause it to move to the closed position.

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: An improved power vent and associated control system for a heating apparatus such as a furnace. The invention utilizes a vent blower and a flow control orifice device permitting the use of a single size air moving device and motor with different size furnaces. The control is arranged to discontinue delivery of fuel to the furnace in the event of a blockage of the furnace flue or a failure of the air moving structure. In one form of the invention, a pressure condition is sensed downstream of the air moving structure to detect the failure conditions. In another form of the invention, the control utilizes structure to sense the speed of the air moving device. The invention comprehends the use of a motor for driving the air moving device which varies in speed substantially between the unloaded and loaded conditions. The air moving device preferably unloads under high discharge pressure conditions, such as by a blocked flue.

Abstract: A hot surface ignition system for a gas furnace and method of making the same are provided, the system comprising a high voltage circuit for being connected to a source of high voltage AC current, the high voltage circuit having a hot surface igniter therein and disposed in the path of gas issuing from a burner that is adapted to be fed gas from a source thereof through an electrically operated gas valve, a low voltage circuit for being connected to a source of low voltage AC current, the low voltage circuit having the gas valve therein and having a thermostatic switch therein controlling the energization of the low voltage circuit with the low voltage AC current, a first relay unit having contacts in the high voltage circuit and controlling the energization of the igniter with the high voltage AC current, and another relay unit having contacts in the low voltage circuit and controlling the energization of the gas valve, the other relay unit comprising two separate relays respectively having contacts that are

Abstract: An ignition control system for a direct ignition gas appliance, such as a furnace. A main gas valve, spark generator, flame sensor, and purge blower are all interconnected to a single controller. The controller issues a purge signal to the blower for a first predetermined period. Thereafter, for a second predetermined period, the controller issues an interconnect signal to allow the main gas valve to open and an ignition signal to cause the ignition source to ignite the gas flowing into the appliance from the valve. If the controller thereafter fails to receive a signal from the flame sensor, the attempt at ignition was unsuccessful. After a predetermined number of unsuccessful attempts at ignition, the controller issues a lockout signal to the valve. Moreover, the controller includes redundant circuits for detecting malfunctions within itself and responsively closing the main gas valve.

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: The invention relates to a method and installation for improving the efficiency of a submerged-combustion heating installation. According to the invention, to prevent thermal stresses injurious to the combustion chamber (3) and avoid the production or penetration of vapors into the top part of the chamber (16), the installation is ventilated (7) with air after the burners (1) have been turned off, for at least sufficient time for adequately cooling the walls of the combustion chamber (3).

Abstract: A burner control apparatus for use with a furnace installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, one or more devices for control of ignition and relay fuel flow, and a modulator controlling air and fuel flow to a main burner for varying heat output. The burner control apparatus comprises a lockout relay for shutting down the furnace, a control device for actuating the ignition and fuel control devices, and a timing circuit that provides several successive and partially overlapping timing intervals of precise relation, including a purge interval, a pilot ignition interval, and a main fuel ignition interval. The present invention includes circuitry for providing a purge interval with the modulator at a high air flow setting. After the purge interval, pilot flame ignition is prevented until the modulator has been moved to a low fire position.

Abstract: An improved power vent and associated control system for a heating apparatus such as a furnace. The invention utilizes a vent blower and a flow control orifice device permitting the use of a single size air moving device and motor with different size furnaces. The control is arranged to discontinue delivery of fuel to the furnace in the event of a blockage of the furnace flue or a failure of the air moving structure. In one form of the invention, a pressure condition is sensed downstream of the air moving structure to detect the failure conditions. In another form of the invention, the control utilizes structure to sense the speed of the air moving device. The invention comprehends the use of a motor for driving the air moving device which varies in speed substantially between the unloaded and loaded conditions. The air moving device preferably unloads under high discharge pressure conditions, such as by a blocked flue.

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: A combustion control apparatus in which a predetermined number of pre-purge and igniting cycles are repeated until ignition takes place successfully. A pre-purge time interval of the second and subsequent igniting cycles is selected shorter than that of the first igniting cycle. When an existing combustion control element which is capable of performing the igniting cycle only once is employed, the intended combustion control is performed by appropriately controlling a reset terminal of the existing combustion control element of signals representative of expirations of the pre-purge time interval and the ignition time interval. The number of the igniting cycles is counted by a counter for stopping operation of the combustion apparatus when a predetermined count value is attained. A novel circuit for the combustion control element is also disclosed.

Abstract: An improved boiler purge control in which purging air is forced into the boiler only after the damper is substantially in its high fire position.

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 device for liquid fuel burners includes an electrically controlled valve which allows the feeding of fuel to the burner, the valve being provided with a retaining winding for permanently allowing the flow of fuel when the burner is in operation. The device further includes a combustion chamber pre-purger and a resistor with determines the end of the pre-purging. The device also includes a flame signaller means having a photo-resistance which responds to a preset low light intensity so as to reduce the current flowing through the resistor to such an extent that its heating becomes insufficient to cause the end of the pre-purging. The photo-resistance responds to a high light intensity by activating the retaining winding of the valve and giving the signals necessary for causing the burner to enter its regular operating mode.

Abstract: A burner control apparatus for use with a fuel installation that has an operating control to produce a request for burner operation, a flame sensor to produce a signal when flame is present in the monitored combustion chamber, and one or more devices for control of ignition and/or fuel flow. The burner control apparatus comprises lockout apparatus for de-energizing the control apparatus, a control device for actuating the ignition and/or fuel control devices, and a timing circuit that provides four successive and partially overlapping timing intervals of precise relation, including a purge timing interval, a pilot ignition interval, and a main fuel ignition interval. The present invention further includes a burner control system which verifies the proper operation of certain sensors in a burner or furnace including particularly the air flow sensor.

Abstract: A combustion control apparatus which controls combustion in a combustor which is a heat source of a hot-water boiler or a hot-air heater includes a memory circuit which generates an alarm signal and also a signal for stopping the operation of the apparatus and which maintains the apparatus in the shutdown state, when an abnormal condition such as abnormal heating or ignition failure is sensed. This memory circuit is protected from malfunction due to noise generated from external output units in the combustion control apparatus by a circuit which detects an abnormality signal with timing other than the timing of generation of noise from the external output units, and the output of this circuit is applied as an input to the memory circuit. The detection circuit is arranged to detect the abnormality signal while receiving clock pulses from a timer as its input, and the phase of its detection timing is selected to be out of phase with the noise generation.

Abstract: This invention relates to a control circuit which controls combustion in a burner acting as a heat source of a hot-water boiler or a hot-air heater. More particularly, the present invention relates to a control circuit having a sequence which includes post-discharge such that electric discharge for ignition is still continued for a predetermined period of time, even after attainment of ignition. In a combustion control apparatus, when ignition is not attained within a predetermined safty period, the igniting operation is stopped by a safty timer for timing this safety period, thereby ensuring the safety. It is necessary to reliably discontinue the igniting operatin even when this safety timer is disabled. The present invention attains this object and ensures the safety with a reduced number of timers.

Abstract: A condition control system in the form of a fuel burner control means is disclosed. A group of relays and their associated contacts are used to control the burner means. The status of the relays and their contacts are continuously checked by a control logic means by having the voltage on key relay output contacts fed into the control logic means through isolated signal transmission means. All of the relays are capable of being deenergized in the event of the need for safety shut down as determined by the control logic means.

Abstract: A control circuit for gas fired burners and the like such as are employed in commercial laundry fabric ironers requiring the energization of a blower motor and the resulting opening of a gas valve and ignition of a gas burner only after an air pressure sensitive switch is actuated through the operation of the blower motor for purging the system of combustible gases.

Abstract: A fuel burner primary control with a pre-purge and extended ignition function has been disclosed. The system has been disclosed as an oil burner which utilizes a voltage regulator to insure that adequate power is supplied to the device and with a time delay on the application of potential to the ignition and oil source to allow for a pre-purge interval. The ignition source is also time delayed to insure a stable flame before the ignition is deenergized.