Abstract: There is described a method and apparatus for controlling the combustion by-product formation rate in at least one burner of a fossil fuel fired power plant. The burner has an associated flame scanner which is focused on a small area of the burner flame to obtain an image signal of the flame. A flame signal that represents properties of temporal combustion in the visible light spectrum of the burner is generated from the image signal. Combustion turbulence at the burner is analyzed from the flame signal by a dynamic invariant that has a relationship to the combustion by-product values and different combustion by-product levels at the burner and the combustion turbulence is correlated to the combustion by-product formation rate at the burner. The method and apparatus can also be used to correlated the combustion turbulence at a multiplicity of burners to the associated combustion by-product formation rate.

Abstract: A method for indirect gas species monitoring based on measurements of selected gas species is disclosed. In situ absorption measurements of combustion species are used for process control and optimization. The gas species accessible by near or mid-IR techniques are limited to species that absorb in this spectral region. The absorption strength is selected to be strong enough for the required sensitivity and is selected to be isolated from neighboring absorption transitions. By coupling the gas measurement with a software sensor gas, species not accessible from the near or mid-IR absorption measurement can be predicted.

Abstract: A method and apparatus for measuring the concentration of at least one gaseous component and/or vaporous component of a gaseous mixture in which a controlled sensor flame is introduced into the gaseous mixture and at least one narrow spectral band in the controlled sensor flame is optically measured. The concentration of the gaseous component using a result obtained from the optical measuring of the at least one narrow spectral band is then calculated. The method of this invention is particularly suitable for substantially real-time control of combustion processes.

Abstract: A pyrometer for use in measuring temperatures in a furnace, has a lens-tube for supporting an optical head in a port of the furnace for viewing an interior of the furnace along a line of sight. The optical head converts infrared radiation to electrical signals. A photometer circuit connected to the optical head processes the electrical signals and a scaling circuit connected to the photometer circuit scales the electrical signals. An output circuit connected to the scaling circuit receives the scaled electrical signals and produces output signals for display or control of the furnace. A power supply connected to the scaling circuit powers the photometer, scaling and output circuits. Calibration in the scaling circuit scales the electrical signals to be most sensitive to a wavelength of middle infrared radiation to which at least one gas component in the furnace is semi-transparent, for measuring the temperature of the at least one gas component.

Abstract: The invention relates to a flame monitor for an oil- or gas-operated burner, having a photosensor which detects the optical flame radiation and an evaluation circuit which is connected downstream of said photosensor and ascertains whether the radiation received by the photosensor corresponds to that of a burning flame and, in the event of a negative result, generates a switch-off signal for the fuel supply, wherein the evaluation circuit determines the number of zero crossings of the processed signal of the photosensor within a predetermined unit of time and compares it with a predetermined limit value, a switch-off signal for the fuel supply being generated when said limit value is undershot, the signal of the photosensor, freed from the DC voltage component and noise, being processed by corresponding amplification to form square-wave pulses.

Abstract: There is described a method and apparatus for controlling the combustion by-product formation rate in at least one burner of a fossil fuel fired power plant. The burner has an associated flame scanner which is focused on a small area of the burner flame to obtain an image signal of the flame. A flame signal that represents properties of temporal combustion in the visible light spectrum of the burner is generated from the image signal. Combustion turbulence at the burner is analyzed from the flame signal by a dynamic invariant that has a relationship to the combustion by-product values and different combustion by-product levels at the burner and the combustion turbulence is correlated to the combustion by-product formation rate at the burner. The method and apparatus can also be used to correlated the combustion turbulence at a multiplicity of burners to the associated combustion by-product formation rate.

Abstract: A flame sensor for sensing the presence of a flame in a burner. The signal from the sensor is passed to an amplifier located adjacent to the sensor and amplified without having a sensor signal contaminated with common mode radiation. The selectively amplified signal between 15 and 80 Hz is processed by a microcontroller located remotely from the sensor and amplifier which microcontroller may terminate or continue burner operation. The integrity of the connection circuitry between the amplifier and the microcontroller is also monitored and burner shutdown occurs if there is a fault in such circuitry.

Abstract: A device for welding overlapping roof membranes comprising a chassis, an air discharge chute and a flame distribution assembly communicating with the air discharge chute. The flame distribution assembly includes a gaseous fuel source inlet, a primary burner, and an ignition source. A control unit ignites the primary burner by the ignition source. The blower connected to an inlet port of the air discharge chute directs heat generated by the primary burner through an air discharge outlet for welding the overlapping roof membranes.

Abstract: A flame-type atomic absorption spectrophotometer forms a flame by igniting a mixture of a fuel gas and a first combustion support gas such as air and then the first combustion support gas is replaced by a second combustion support gas such as nitrous oxide with a faster combustion speed. An optical sensor is disposed near the flame to detect the quantity of light therefrom. A gas flow rate control device independently controls the flow rates of the fuel gas, the first combustion support gas and the second combustion support gas to the flame. A combustion control unit serves to switch the gas to be supplied to the flame from the first combustion support gas to the second combustion support gas, based on how much the quantity of light detected by the optical sensor changes between the time of ignition and after the flow rate of the fuel gas and/or the first combustion support gas is changed.

Abstract: A pilot system including a pilot including a nozzle and a light sensor adjacent to the nozzle. The light sensor determines whether or not the pilot flame is in a predetermined position relative to the nozzle.

Abstract: Systems and methods are disclosed that optimize the combustion process in various reactors, furnaces, and internal combustion engines. Video cameras are used to evaluate the combustion flame grade. Depending on the desired form, standard or special video devices, or beam scanning devices, are used to image the combustion flame and by-products. The video device generates and outputs image signals during various phases of, and at various locations in, the combustion process. Other forms of sensors monitor and generate data signals defining selected parameters of the combustion process, such as air flow, fuel flow, turbulence, exhaust and inlet valve openings, etc. In a preferred form, a neural networks initially processes the image data and characterizes the combustion flame. A fuzzy logic controller and associated fuzzy logic rule base analyzes the image data from the neural network, along with other sensor information.

Abstract: In a method of controlling thermoacoustic vibrations in a combustion system having a combustion chamber and a burner, the fluid shear layer forming in the region of the burner is acoustically excited. An apparatus for controlling thermoacoustic vibrations in a combustion system having a combustion chamber and a burner is distinguished by the fact that device(s) for the acoustic excitation of the working gas are arranged in the region of the burner.

Abstract: A sensor for detecting the flame occurring during a flashback condition in the fuel nozzle of a lean premix combustion system is presented. The sensor comprises an electrically isolated flashback detection electrode and a guard electrode, both of which generate electrical fields extending to the walls of the combustion chamber and to the walls of the fuel nozzle. The sensor is positioned on the fuel nozzle center body at a location proximate the entrance to the combustion chamber of the gas turbine combustion system. The sensor provides 360° detection of a flashback inside the fuel nozzle, by detecting the current conducted by the flame within a time frame that will prevent damage to the gas turbine combustion system caused by the flashback condition.

Abstract: The oxy-fuel burner comprises at least one fuel supply pipe (16) and at least one pipe (18) for supplying an oxygen-rich gas, the said outlets of the pipes being directed approximately in the same direction, the burner being designed to be mounted through a wall of a furnace with the pipes directed into the furnace. It carries at least one auxiliary member (50, 60) intended to act on the flame and the said auxiliary member (50, 60) is placed on the burner upstream of the zone where the fuel gas and the oxygen-rich gas meet.

Abstract: The invention relates to a flame monitor for an oil- or gas-operated burner, having a photosensor which detects the optical flame radiation and an evaluation circuit which is connected downstream of said photosensor and ascertains whether the radiation received by the photosensor corresponds to that of a burning flame and, in the event of a negative result, generates a switch-off signal for the fuel supply, wherein the evaluation circuit determines the number of zero crossings of the processed signal of the photosensor within a predetermined unit of time and compares it with a predetermined limit value, a switch-off signal for the fuel supply being generated when said limit value is undershot, the signal of the photosensor, freed from the DC voltage component and noise, being processed by corresponding amplification to form square-wave pulses.

Abstract: There is provided an automatic burner driven generator system for powering a load. The Generator system generally comprises a burner unit for generating a thermal energy; a thermoelectric converter unit operatively coupled to the burner unit for transducing at least a portion of the thermal energy to a first electric power signal; a rechargeable battery unit operable to generate an output power signal for powering the load; a charging unit operably coupled to the thermoelectric converter and rechargeable battery units; and, a controller for automatically controlling the actuation of the units in programmed manner. The charging unit is operable to adaptively convert the first electric power signal to a second electric power signal for charging the rechargeable battery unit. The controller includes a microprocessor unit programmable configured to selectively actuate the units in accordance with a plurality of predetermined operational states.

Abstract: A cooking appliance with a cooktop including at least one gas burner includes a control for sequentially delivering gas and igniting the gas to burner ports. The control comprises a valve with a responsive element for controlling gas flow to the burner ports, an ignition module for generating a drive signal to an ignitor, an electronic controller interfacing with the ignition module and coupled to a driver for actuating a responsive element in the valve. The driver that causes displacement of the responsive element includes a pick up actuator enabling the responsive element to initiate a status that opens the passageway. The valve also includes a holding actuator that enables the responsive element to maintain the status of the passageway as open when flame is detected at the burner.

Abstract: Combustion variables are diagnosed using sensors to measure turbulence in the post-flame zone as well as in the flame envelope of a combustor. Output signals from the sensors are processed and a set of statistical functions are calculated which are correlated with specific combustion variables, such as the concentration of unburned carbon in fly ash. A special sensor mounting box provides reliable long-term operation in harsh combustor environment, without a supply of cooling or protective air flow.

Abstract: Methods and apparatus are presented using tunable diode lasers for monitoring and/or controlling a high temperature process using an oxidizer containing O2 and organic fuel. Real-time monitoring of key species such as O2, CO, and H2O allow determination of the global or local stoichiometry, gas temperature, particulate concentration, and air entrainment levels into the process. Coupling the measured information with a control system provides a means for optimizing and controlling the process.

Abstract: A method and apparatus is provided for initiating and stabilizing fuel combustion in applications such as gas turbine electrical power generating engines and jet turbine engines where it is desired to burn lean fuel/air mixtures which produce lower amounts of NOx. A laser induced spark is propagated at a distance from the fuel nozzle with the laser ignitor being remotely located from the high temperature environment of the combustion chamber. A laser initiating spark generated by focusing high peak power laser light to a sufficiently tight laser spot within the fuel to cause the ionization of air and fuel into a plasma is unobtrusive to the flow dynamics of the combustion chamber of a fuel injector, thereby facilitating whatever advantage can be taken of flow dynamics in the design of the fuel injector.

Abstract: The present invention relates to flame detection apparatus and method. The present invention provides a method and apparatus for monitoring the status of a combustion unit having at least one bumer. Initially, a digital image of a flame corresponding to a flame is acquired. Next, a value for the relative light intensity of a frame defining an area of the image corresponding to the flame for the burner is calculated. The relative light intensity value is compared against a tolerance range for the frame. If the relative light intensity value is outside the tolerance range then an alarm state output is generated.

Abstract: Systems and methods are disclosed that optimize the combustion process in various reactors, furnaces, and internal combustion engines. Video cameras are used to evaluate the combustion flame grade. Depending on the desired form, standard or special video devices, or beam scanning devices, are used to image the combustion flame and by-products. The video device generates and outputs image signals during various phases of, and at various locations in, the combustion process. Other forms of sensors monitor and generate data signals defining selected parameters of the combustion process, such as air flow, fuel flow, turbulence, exhaust and inlet valve openings, etc. In a preferred form, a neural networks initially processes the image data and characterizes the combustion flame. A fuzzy logic controller and associated fuzzy logic rule base analyzes the image data from the neural network, along with other sensor information.

Abstract: A method, and a system for implementing the method, for detecting whether a flame is an on state or alternatively is in an off state. The method includes (i) detecting the flame and generating therefrom a flame signal capturing one or more attributes of the flame; (ii) using a high-order cumulant-to-moment formula to determine high-order cumulants for a random variable process representation of the flame signal; and (iii) determining whether the flame is on or off using the high-order cumulants. The method includes the step of applying the high-order cumulant-to-moment formula in a self-learning algorithm to determine flame-on high-order cumulants and flame-off high-order cumulants for the flame. Step (iii) includes comparing the high-order cumulants to the flame-on high-order cumulants and the flame-off high-order cumulants to determine whether the status of the flame is on or off.

Abstract: In an apparatus for monitoring a hydrocarbon flame, a plurality of radiation sensors detect electromagnetic radiation emitted by the flame. Each of the sensors is provided with a narrow band filter so that the corresponding sensor is responsive only to a narrow range of wavelengths. In this manner, one of the sensors is made responsive to emissions due to transient species in the flame and one of the sensors is made responsive to emissions from a non-transient species in the combustion region. The signals from the radiation sensors are converted to digital and applied to a central processing unit where they are compared to produce an output indicative of the combustion conditions in the flame. An output unit responds to the output signal from the central processing unit to adjust the air fuel ratio in the flame to a desired level, such as just above stoichiometric.

Abstract: In accordance with the present invention, methods and apparatus to control the combustion of a burner are presented which overcome many of the problems of the prior art. One aspect of the invention comprises a burner control apparatus including a device for viewing light emitted by a flame from a burner, a device for optically transporting the viewed light into an optical processor, an optical processor for processing the optical spectrum into electrical signals, a signal processing for processing the electrical signals obtained from the optical spectrum, and a control device which accepts the electrical signals and produces an output acceptable to one or more oxidant or fuel flow control devices. The control device, which may be referred to as a “burner computer,” functions to control the oxidant flow and/or the fuel flow to the burner.

Abstract: A burner assembly includes a number of gas burners each utilizing a radiant ceramic plaque, the burners are disposed in confined combustion chambers where they direct heat towards a heat-receiving surface so that by this arrangement the plaque receives a substantial amount of back radiation.

Abstract: The invention relates to a flame monitor for blue-burning flames having a photosensor whose output signal is evaluated in such a manner that the fuel supply is switched off not only when the flame is extinguished but also when its color moves too far into the yellow band.

Abstract: Characteristics of a flame within a turbine or burner are determined based upon ultraviolet, visible, and infrared measurements of the flame. The measurements include a measurement of the amplitude of frequency bands that are indicative of an efficient combustion process, such as those that increase when the flame temperature increases. The measurements also include of the amplitude of frequency bands that are indicative of an inefficient combustion process, such as those that do not vary, increase a relatively small amount, or decrease when the flame temperature increases. The temperature of the flame may therefore be determined accurately, to facilitate efficient operation of the turbine or burner while minimizing polluting emissions. Contaminants in the turbine or burner are detected, and a degree of contamination measured, by detection of energy levels for particular wavelengths associated with a respective contaminant.

Abstract: A combustion system includes a combustion chamber. A fan is connected to the combustion chamber. The fan has a spin velocity. A burner is adjacent the combustion chamber. The burner defines one or more flame openings. Each flame opening has a cross section. An obstacle is associated with each of the one or more flame openings. Each obstacle is within the combustion chamber. A mixture of fuel gas and air having a mixture temperature is discharged at a discharge velocity from the one or more flame openings. A flame is positioned along the burner substantially detached from the one or more openings. A flame position sensor senses the position of the flame and generates a flame position signal based on the sensed position of the flame. A control processor maintains the flame around a prefixed optimum position by controlling a characteristic variable quantity of the mixture based on the flame position signal.

Abstract: A fuel oil burner utilizing a hot surface ignition with an ignitor that is fully sintered and has essentially no porosity, a voltage phase regulator circuit for applying rectified half-wave AC line voltage, full-wave rectified AC, or either half-wave or full-wave rectified AC line voltage to the ignitor to supply power thereto, and AC line voltage to a blower motor, an AC-to-DC converter, a DC voltage preregulator, and a DC voltage regulator for providing twelve volts DC for operation of a control circuit that has a first time constant circuit for preheating the ignitor and maintaining the ignitor at consistent ignition temperature for a predetermined ignition trial time period and a second time constant circuit for driving second and third motor drive circuits.

Abstract: Characteristics of a flame within a turbine or burner are determined based upon ultraviolet, visible, and infrared measurements of the flame. The measurements include the amplitude of frequency bands that are indicative of an efficient combustion process, such as those that increase when the flame temperature increases. The measurements also include the amplitude of frequency bands that are indicative of an inefficient combustion process, such as those that do not vary, increase a relatively small amount, or decrease when the flame temperature increases. The temperature of the flame may therefore be determined accurately, to facilitate efficient operation of the turbine or burner, while minimizing polluting emissions.

Abstract: A fail safe gas furnace optical flame sensor uses a transconductance amplifier with low photodiode current to sense the presence or absence of a gas flame within the burner of a gas furnace. The photodiode signal appears as the only negative voltage signal in the circuit, and the equivalent resistance feedback network is redundantly designed, thus ensuring that no false flame-on conditions will be detected due to the failure of a single resistive component. Because it does not reside within the flame, the sensor is immune to false flame-off conditions caused by material deposition and corrosion of the sensor.

Abstract: In accordance with the present invention, methods and apparatus to control the combustion of a burner are presented which overcome many of the problems of the prior art. One aspect of the invention comprises a burner control apparatus including a device for viewing light emitted by a flame from a burner, a device for optically transporting the viewed light into an optical processor, an optical processor for processing the optical spectrum into electrical signals, a signal processing for processing the electrical signals obtained from the optical spectrum, and a control device which accepts the electrical signals and produces an output acceptable to one or more oxidant or fuel flow control devices. The control device, which may be referred to as a "burner computer," functions to control the oxidant flow and/or the fuel flow to the burner.

Abstract: A method and an apparatus for monitoring fuel combustion status in a burner such as a boiler and a gasifier with high accuracy, high reliability and fast response are disclosed. The apparatus comprises a series of fiber optic flame monitors that are installed next to each nozzle inside said burner to determine temperature, flame flash frequency and the burned fuel particle density. In terms of a master controller and a group of on-line controllers, the optimized combustion of the burner is approached by monitoring the combustion status of each nozzle and regulating the discharges of air or oxygen and fuel to each nozzle, in accordance with the comparison of the data detected by flame monitors and optimal data.

Abstract: A portable heater and cooker system is provided to apply radiant and conductive heat from a heating component to an enclosure area or a cooking utensil, using a heat generated chimney effect and manual manipulation. In addition, user safety is assured with an oxygen depletion sensor and a ventilating panel for the enclosure.

Abstract: A method of monitoring for the presence of a flame in a burner includes the steps of providing a UV bulb sensor (1) whose electrical output signal in response to a voltage applied across the sensor varies according to the presence or absence of UV light radiating from a burner flame, connecting the sensor across a voltage source (2) which is adjustable, the voltage source being set at a first setting, and monitoring the output signal from the bulb sensor during operation of the burner and automatically altering the setting of the voltage source from the first setting in accordance with the monitored output signal to maintain the output signal within a predetermined range.

Abstract: Systems and methods are disclosed that optimize the combustion process in various reactors, furnaces, and internal combustion engines. Video cameras are used to evaluate the combustion flame grade. Depending on the desired form, standard or special video devices, or beam scanning devices, are used to image the combustion flame and by-products. The video device generates and outputs image signals during various phases of, and at various locations in, the combustion process. Other forms of sensors monitor and generate data signals defining selected parameters of the combustion process, such as air flow, fuel flow, turbulence, exhaust and inlet valve openings, etc. In a preferred form, a neural networks initially processes the image data and characterizes the combustion flame. A fuzzy logic controller and associated fuzzy logic rule base analyzes the image data from the neural network, along with other sensor information.

Abstract: An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment.

Abstract: A detector for use in a combustion system includes a probe having a tip adapted for placement through a singular aperture in the mixing area of a combustion system. First and second channels are derived from the probe output and are used to detect a flashback or flameout condition.

Abstract: A powered multi-fuel burner has a burner assembly which utilizes an air aspirated nozzle. An air compressor provides air to the air aspirated nozzle and to a fuel-holding tank where the fuel within the tank is put under air pressure thereby to enhance its flow to the air aspirated nozzle. A bleed valve is positioned between the air compressor and the fuel thank thereby to increase or decrease the air pressure within the fuel tank. By increasing and decreasing the air pressure within the tank, the burner can produce heat over a range of operation.

Abstract: A fuel oil burner utilizing a hot surface ignition with an ignitor that is fully sintered and has essentially no porosity, a voltage phase regulator circuit for applying rectified half-wave AC line voltage, full-wave rectified AC, or either half-wave or full-wave rectified AC line voltage to the ignitor to supply power thereto, and AC line voltage to a blower motor, an AC-to-DC converter, a DC voltage preregulator, and a DC voltage regulator for providing twelve volts DC for operation of a control circuit that has a first time constant circuit for preheating the ignitor and maintaining the ignitor at consistent ignition temperature for a predetermined ignition trial time period and a second time constant circuit for driving second and third motor drive circuits.

Abstract: A system for automatically admitting and regulating the flow-rate of an alkaline substance admitted to the combustion chamber (10) of a refuse incineration plant for the hot destruction of the acids contained in the combustion fumes, comprising sensors (22, 23, 24, 25, 51, 124, 140) for detecting the concentration of the acids in the fumes in the combustion chamber (10) and working conditions of the plant such as temperature, flow-rate and humidity of the fumes, and processing means (26, 27) connected to the sensors for identifying, in dependence on the concentration of acids and of the working conditions, a flow-rate of an alkaline substance to be admitted to the combustion chamber in order to achieve a destruction yield which reduces the concentration of acids in the fumes discharged from the plant to a predetermined value, and for operating flow-rate regulation members (40) for admitting to the combustion chamber the flow-rate of an alkaline substance thus identified.

Abstract: In accordance with the present invention, methods and apparatus to control or monitor the combustion of a burner are presented which overcome many of the problems of the prior art. One aspect of the invention comprises a burner control apparatus comprising means for viewing light emitted by a flame from a burner, means for optically transporting the viewed light into an optical processor, optical processor means for processing the optical spectrum into electrical signals, signal processing means for processing the electrical signals obtained from the optical spectrum, and control means which accept the electrical signals and produce an output acceptable to one or more oxidant or fuel flow control means. The control means may be referred to as a "burner computer", which functions to control the oxidant flow and/or the fuel flow to the burner.

Abstract: A signal processing method and apparatus for analyzing operation of a combustion burner. Responsive to a signal produced by a flame sensor which monitors a burner flame, a fluctuational component of the signal is converted into an extremum function having a floating extremum point with a frequency coordinate which varies in the frequency domain with changes in combustion conditions. A current extremum value of the extremum function is calculated. Then, in relation to the current extremum value, a value of at least one parameter of the extremum function is calculated, such function being related to the combustion characteristic. The apparatus comprises a processor and memory coupled thereto, the memory having stored therein a plurality of instructions which, when executed by the processor, cause the processor to perform the aforementioned operations.

Abstract: An infrared emittance combustion analyzer utilizing detectors in a flame burner which monitor the radiation at two preselected wavelengths. The respective radiation signals are filtered to eliminate DC signal variations, rectified and converted into a DC value which is representative of the measured radiation signals. The respective DC values are formed into a ratio which is compared against a predetermined setpoint signal, and the error signal resulting from this comparison is utilized to drive an electromechanical controller which adjusts either the air damper or the fuel damper to adjust the fuel/air mixture which is fed into the burner.

Abstract: A detection system includes flame sources at least two of which are independently controllable; photodetectors each having an independent view of the flame sources and being capable of producing a respective current signal in response to flames produced by the flame sources; and a device for analyzing the current signals to determine state values of a plurality of state variables and transform the state values into at least one parameter value. A number of the flame sources is at least as high as a number of the state variables, and a number of the photodetectors is at least as high as the number of the state variables. In one embodiment, the flame sources include gas burners in a gas combustion chamber, the photodetectors include silicon carbide photodiodes, and the parameter value is representative of fuel rate, temperature, acoustic dynamics, nitrogen oxide concentration, or carbon monoxide concentration.

Abstract: A gas fired appliance measures infrared emissions from a metal object heated in a combustion chamber to evaluate combustion. Associated circuitry uses the evaluation to control operational parameters of the appliance, including fuel and air fed to the appliance. A second metal object, prior to fuel ignition, is electrically heated to emit infrared radiation. Infrared emissions from the second metal object, indicative of the temperature thereof, are monitored to assure an ignition temperature to ignite a combustible air and fuel mixture. A fan directs a stream of ambient air upon the second metal object to cool the same and reduce the infrared emanating therefrom. The reduction in infrared from the second metal object is monitored to verify proper fan operation.

Abstract: An ionization chamber for use in a smoke detector includes first and second outer electrodes and a non-reflective center electrode. The non-reflective center electrode can be formed as a metal electrode having a non-reflective coating or as a non-reflective, conductive plastic elements. The ionization chamber can be incorporated into combination smoke detector which includes a photoelectric sensor. A non-reflective center electrode, associated with the ion-type sensor is symmetrically located in the detector and displaced from the photoelectric sensor.

Abstract: A method and system of regulating the air to fuel ratio supplied to a burner to maximize the combustion efficiency. Optical means are provided in close proximity to the burner for directing a beam of radiation from hot gases produced by the burner to a plurality of detectors. Detectors are provided for sensing the concentration of, inter alia, CO, CO.sub.2, and H.sub.2 O. The differences between the ratios of CO to CO.sub.2 and H.sub.2 O to CO are compared with a known control curve based on those ratios for air to fuel ratios ranging from 0.85 to 1.30. The fuel flow is adjusted until the difference between the ratios of CO to CO.sub.2 and H.sub.2 O to CO fall on a desired set point on the control curve.

Abstract: A fuel oil burner utilizing a hot surface ignition with an ignitor that is fully sintered and has essentially no porosity, a circuit for applying AC line voltage to the ignitor and to a blower motor, an AC-to-DC converter for providing twelve volts DC for operation of a control circuit that has a first time constant circuit for preheating the ignitor and maintaining the ignitor at an ignition temperature for a predetermined ignition trial period of time, a second time constant circuit for starting the blower motor and providing fuel to the combustion chamber for a predetermined time concurrent with the ignition trial period, and a third time constant circuit that either maintains the fan blower in its energized state if a flame of sufficient magnitude and frequency is detected and for de-energizing the blower motor if the flame is not detected in less than one second after the ignitor is de-energized.