Abstract: Oil shale having a relatively wide range of heating value is combusted by supplying the oil shale and a further fuel having a heating value greater than the heating value of the oil shale to a combustor. The oil shale is fed to the combustor at a substantially fixed rate, independently of the heating value of the oil shale, and the further fuel is fed to the combustor at a rate such that the heating value of the fuel in the combustor remains substantially constant in the face of variations in the heating value of the oil shale. Preferably, the temperature of combustion of the products of combustion is the parameter used to control the rate at which the further fuel is fed to the combustor.

Abstract: A continuous-flow steam generator includes a combustion chamber having a number of burners for a fossil fuel and a gas-tight containment wall formed from at least approximately vertically disposed evaporator tubes through which a flow passes upwards from below on the feed-water side. A method and a system for starting up the continuous-flow steam generator avoid start-up losses by setting a water level in the evaporator tubes and a ratio of the fuel stream to the feedwater stream in such a way that the water evaporates completely during passage through the evaporator tubes, so that water is no longer present at the evaporator outlet. A start-up system having a setting device for setting the water level in the evaporator and for setting the ratio of the fuel stream to the feed-water stream, is used for this purpose.

Abstract: A speed controller for motors of a solid fuel stove or stoker includes a bidrectional switch, such as a thyristor, to be interposed along an ac power line. The controller operates in a speed control mode for sending reduced power to a stove when a space thermostat is satisfied. The speed control mode may be automatically modulated between minimum and maximum in response to remote sensors, such as a thermistor. The controller may also provide a power-up mode for a predetermined period of time to supply full power to stove motors upon start-up, such as after a power outage. The controller may also provide full power to the stove motors when the motors are being powered by an inverter.

Abstract: A feeder system for measuring and controlling the massed feed rate of particulate fuel material, such as coal particles, made up of a group of volumetric feeders and a gravimetric feeder coupled to the group of volumetric feeders. The system controls the fuel feed rate of the volumetric feeders based upon data communicated from the gravimetric feeder.

Abstract: A process for burning solids on a sliding fire grate system where each of the combustion control criteria are measured and controlled individually for each grate plate comprising the grate system.

Abstract: A control system for a fuel-fired furnace and more specifically the control of the stoichiometric ratio of the combustion process occurring within the furnace of a steam generating power plant. The control system, when so employed, is capable of regulating the distribution of air flow to the combustion process such that the formation of oxides of nitrogen are maintained at acceptable levels. The control system includes in general a stoichiometric subsystem that determines the mass flow rate of air required to maintain the stoichiometric ratio within the combustion process; an override protection subsystem which ensures control precedence of the windbox-to-furnace pressure differential over the stoichiometry subsystem; and an overfire air subsystem that acts to apportion air flow amongst the various levels of overfire air within the boiler.

Abstract: To carry out a process for regulating individual factors or all factors influencing combustion on a furnace grate, a radar device is provided primarily. This radar device serves to detect the three-dimensional distribution of the fuel mass on at least one preferred region of the grate. In addition, an infrared camera is provided for supplying information on the burn-up behavior of the fuel located on the grate. By using the measured quantities obtained from these two devices, control variables may be derived within a regulating unit for influencing the grate speed, the charging device, the amount and composition of supplied primary air, the amount and composition of supplied secondary air, the speed of the ash roller and the temperature of the air preheating device so that the furnace performance can be adapted to the steam output requirement.

Abstract: A control system of coal pulverizer associated with a rotary classifier, applicable to a pulverized coal burning boiler or the like, includes a function generating section, a computing section, and a rotational speed controlling section. The function generating section receives a signal representing a coal feed rate and outputs signals representing a preset proper range of a current to be fed to the motor of the coal pulverizer for such coal feed rate. The computing section is responsive to a signal representing the current motor current and the signals produced by the function generating section to output a command signal which will maintain the speed of the rotary classifier when the motor current represented by the motor current signal is within the proper range, and to output a command signal which will decrease or increase the speed of the rotary classifier, respectively, in the case where the same motor current has increased or decreased beyond the proper range.

Abstract: An improvement to a coal processing system where hard materials found in the coal may cause jamming of either inflow or outflow rotary airlocks, each driven by a reversible motor. The instantaneous current used by the motor is continually monitored and compared to a predetermined value. If an overcurrent condition occurs, indicating a jamming of the airlock, a controller means starts a "soft" reverse rotation of the motor thereby clearing the jamming. Three patterns of the motor reversal are provided.

Abstract: A new and improved fireplace log dispensing apparatus includes a gravity feed chute assembly for receiving a plurality of logs to be burned in a fireplace, and a log dispenser assembly, connected at a bottom of the gravity feed chute assembly, for selectively dispensing logs into the fireplace, preferably onto a grate in the fireplace. The gravity feed chute assembly includes a queue-forming assembly for arranging the plurality of logs into a queue. The log dispenser assembly dispenses one log at a time from the queue onto the fireplace grate. More specifically, the log dispenser assembly includes a number of movable partitions and a stationary wall which define a sequestering chamber for isolating one log at a time from the queue and for moving the isolated log onto the fireplace grate. The movable partitions are in the form of vanes arrayed radially around a central shaft which rotates on bearings. The movable partitions are driven by weight of the queue of logs.

Abstract: In refuse incineration, it has been determined that the legal requirements governing refuse incineration can be more easily met by maintaining a uniform depth of charge on the grate. The charging of the refuse and the transport speed of the charge produced by movable refuse feeders can be regulated as a function of the quantity of refuse in the incinerator or in its individual zones. The load of the drive mechanism can be used for measurement and control purposes for maintaing a uniform refuse depth.

Abstract: A particulate delivery system is disclosed for particulate burners in which a hopper is provided for supplying particulate fuel to a hopper discharge opening. A rotating turntable is provided below the hopper discharge opening and includes at least one and preferably a plurality of flexible resilient vanes rotating with the turntable. A wall partially encircles the vanes and is closed on its bottom end by the upper surface of the turntable. The wall includes a lateral discharge opening that facilitates controlled discharge of the particulate fuel over the peripheral edge of the turntable. A chute receives the discharged particulate material, and drops it into a burn pot of the associated particulate burner.

Abstract: A biomass fuel gasification chamber, blast tube, and heat exchange chamber are interconnected horizontally and subjected to negative drawing pressure by a large variable speed chimney fan. An auger with an air lock feeds biomass fuel automatically into the gasification chamber. Fuel is moved across the gasification chamber on a partially serrated sloping grate. Three stages of fuel activity are created: anaerobic heating for pyrolysis, combustion, and incandescent charcoal oxydation for gasification. A variable speed fan, variable flue, and directional air duct and baffles control the stages with underfire air. A programmed auger in an airtight chamber removes ash automatically. In large systems a hydraulic moving wedge floor assists the fuel feeding auger and a moving sloping grate moves the fuel. A fan and long preheating duct with baffles and fins inside the gasification chamber preheat and direct air into a blast tube leading from the gasification chamber.

Abstract: An automatic firebox provided with a fuel hopper that delivers fuel through a pivoting funnel to a grate burning area. The grate burning area is provided with at least one pivoting fuel grate which operates automatically in sequence with the fuel feed and hopper so as to provide automatic stoking. An automatic control operated by temperature and/or time is disclosed.

Abstract: A method and apparatus for feeding solid material into a pressurized combustion or gasification plant in stages. The feed apparatus (10) is provided with an inlet (18), sluice chamber (30), and outlet (20). In a loading stage, solid material is conveyed through the inlet into the sluice chamber. The loaded sluice chamber is transferred to an unloading stage. During the transfer stage, the inlet (18) is closed. During the unloading stage, solid material is conveyed through the outlet (20) into a pressurized space (26). The volume of the sluice chamber (30) is adjustable so that the volume is enlarged during the loading stage and reduced during the unloading stage. The volume is adjusted e.g. by a piston (38).

Abstract: A storage bin arrangement especially suited for receiving, storing and discharging, in accordance with a combination of induced vertical flow and impelled retrieving concepts, bulk solid materials, in one embodiment of which essentially the entire bin itself is arranged for responding to a circular conveying type vibratory helical stroke movement generated by a pair of electric motors secured to the opposite sides of the bin in oppositely oriented positions to dispose their respective driving shafts at opposite, typically 45 degree angulations with respect to the horizontal, and with each such motor shaft driving a pair of eccentrically oriented weights, with the bin having a low profile bottom section equipped with one or more off center located, vertically oriented, vertically rectilinear, discharge chute arrangements and having one or more internally applied baffles, either of inverted cone type or one or more rows or levels of internally applied centerless, radial, sidewall mounted type, in spaced relatio

Abstract: A pellet fuel combustion assembly including a fuel container, an auger for transferring pellet fuel to a burnpot, a top-opening burnpot for receiving the fuel, and an igniter. The burnpot is preferably constructed of insulative ceramic and includes a base portion defining an ignition compartment below the floor of the burnpot. An opening in the floor of the burnpot leads down a ramp to conduct fuel pellets to a position spaced from but closely adjacent the igniter. An air intake port leading into the ignition compartment causes air flow by the hot igniter causing the fuel to ignite by heat conductance as well as radiation. The igniter, once ignition has taken place, is cooled by the air flow and is separated from the extreme temperatures of the combustion chamber by the insulative floor, thus giving a long service life.

Abstract: A fuel metering bin level control for a wood chip bin feeding a boiler wherein the wood chips have a high propensity to bridge the bin when packed, the level control includes a short chute through which the chips are fed into the upper portion of the bin and a pair of doors in the chute are opened and closed by pneumatic cylinders operating through four bar linkages in response to signals from a level transmitter to maintain the level of wood chips in the fuel metering bin within a range that prevents the chips from bridging the bin and allows the feed to the bin to be continuous with excess chips being diverted to a silo for storage and future use.

Abstract: An air swept fuel feeder for feeding particulate fuel into a furnace and having a closely coupled hopper, fuel metering device and air swept delivery plate. An alternate embodiment is disclosed in which a second fuel is delivered to the furnace by an air swept plate.

Abstract: The apparatus and method are improvements over the refuse derived fuel (RDF) handling system disclosed in applicant's U.S. Pat. No.

Abstract: A furnace system for the automatic, continuous and efficient ignition and combustion of pelletized or similar fuel. An electric-arc ignition means responsive to a thermostat is combined with a non-conductive refractory fire pot with air passageways on the bottom surface of the fire pot, two electrodes configured relative to said fire pot and a system control means, for controlling and sequencing the operation of the system elements. A system control means is also disclosed which de-energizes the fuel feed device if the temperature in the combustion chamber exceeds a pre-determined value, automatically re-energizes the fuel feed device once the temperatue falls back within acceptable levels, and which de-energizes the fuel feed device if the temperature measured in the combustion chamber falls below a pre-determined value.

Abstract: An automatic log feeder for fireplaces is provided which includes an upper horizontal conveyor, an intermediate carriage mechanism and a lower horizontal conveyor. The upper horizontal conveyor is used to store a plurality of logs outside of a building and to advance individual logs through the feeder as desired. Through use of a unique guide rail and rail following bracket the intermediate carriage mechanism receives individual logs from the upper conveyor and lowers them to the lower conveyor while simultaneously changing orientation of the individual logs by 90.degree. before depositing them onto the lower conveyor. The lower conveyor is adapted to automatically advance individual logs into the fireplace in a cantilevered fashion before gently tipping them onto the fireplace grating, or, allows for manual removal of the log from the lower conveyor through an access door extending to the interior of a building.

Abstract: A calorimetry system for measurement of the heating value of coal having a combustor 24 and a mixing unit 30 wherein heat from combustion gases is transferred to air. The system has a gravimetric feeder 64 for providing coal at a measured mass feed rate; the coal including any moisture present therein. The coal is pulverized in an air-driven mill or pulverizer 14 which is fed coal from the feeder and is separated by a cyclone separator 16 into two streams; one carrying coal and air mixed together in a controlled ratio to the combustor. The air which drives the separator, together with fines of the coal and moisture is fed to an afterburner 26 of the combustor so that the thermal dynamics of the entire coal stream is involved in the heating value measurement. Instrumentation measures the flow rates of cooling air, primary air which carries the coal streams into the combustor and secondary combustion air as well as the mass flow rates of the coal into the combustor as measured with the gravimetric feeder.

Abstract: A storage bin arrangement especially suited for bulk solid material storing and discharge in accordance with impelled retrieving concepts, in one embodiment of which essentially the entire bin itself is arranged for responding to a circular conveying type vibratory helical stroke movement generated by a pair of electric motors secured to the opposite sides of the bin in oppositely oriented positions to dispose their respective driving shafts at opposite, typically, 45 degree angulations with respect to the horizontal, and with each such motor shaft driving a pair of eccentrically oriented weights, with the bin having a low profile bottom section equipped with one or more vertically oriented, vertically rectilinear, discharge chute arrangements and having one or more inverted cone inserts applied internally thereof in spaced relation above the bin low profile bottom section, and in a second embodiment, a bin actuator having the features indicated above is mounted below a large discharge opening in a convention

Abstract: An apparatus for burning waste refuse having a heterogeneous composition comprising means defining a combustion chamber having an inlet for charging waste refuse therein and an outlet for discharging combustion gases therefrom, means disposed within the combustion chamber for agitating waste refuse charged therein, means for sensing the temperature differential of combustion gases emanating from the burning waste refuse disposed on the agitating means, between spaced points along the path of flow of the emanating combustion gases, and means responsive to variations of the sensed temperature differential relative to a preselected temperature differential for adjusting the operation of the agitating means.

Abstract: An apparatus for comminuting and stoking of straw bales, and for automatic stoking of chips, pieces of wood, paper, industrial waste, garbage, lignite, coal, briquettes, pellets, and similar solid fuel includes a number of substantially parallel reciprocating or eccentrically moved serrated rods situated in connection with a feeding opening of a furnace. The serrated rods are operatively positioned for comminuting fuel and for tearing any retaining material utilized to contain the fuel. A feeder is provided for feeding fuel onto the serrated rods. A grate is situated between the serrated rods and a conveyor supplies fuel into the furnace.

Abstract: The invention relates to a method and system for modulating the firing temperature in a rotary kiln. The method comprises determining the absolute content of one or more inorganic constituents present in the coal feed for determining the total ash content in the coal. In the event that the temperature in the kiln is different from the required temperature, then a sweetner fuel is fed to the burner with or without a change in the flow of coal. Alternatively, only the amount of flow of coal to the burner is reduced or increased.

Abstract: A system for handling refuse derived fuel (RDF) devised to make RDF fired power plants practical, that includes a method and apparatus for receiving, storing and discharging, distributing and feeding RDF at the plant that accepts such material for fuel, which has been shredded to a predetermined nominal size and usually has most of the ferrous metals removed therefrom, which system includes a relatively large activated bin for primary surge capacity purposes that initially receives and stores the RDF, to provide a binned quantity of same from which as continuous flow of the RDF can be generated that will result in a pulsation free, steady supply of RDF to the plant furnace or furnaces, for firing the power plant involved, with one or more trains located adjacent the locale of the plant furnace to be fired, each of which includes several metering activated bins that are actuated to supply an underlying vibrating feeder that conveys the RDF to the furnace fuel chute, with the activated metering bins of each tra

Abstract: A method and apparatus for controlling moisture content of a solid, such as pulverized coal, conveyed to a reactor, such as a gasifier, by controlling the temperature of a gas injected into a pulverizer or dryer based on the moisture content control of the coal transported to the gasifier.

Abstract: A new and improved system for feeding solid particulate material such as refuse derived fuel for burning in a combustion reactor vessel such as a boiler includes a fuel injector chute having a lower end for directing a flow of said solid particulate material into the vessel and an upper end for receiving a flow of said material. A feeder is provided having a discharge end for delivering a continuous controllable flow of said material to the inlet of the injector chute and a plurality of separate, spaced apart, vibratory feed hoppers are mounted above the feeder to supply the feeder with a steady flow of material from one or both hoppers. Each hopper is adapted for holding a reservoir or supply of said solid particulate material and is selectively controllable to provide a steady flow of solid particulate material into the feeder for delivery through the injector chute to the combustion reactor vessel.

Abstract: An automatic stoker boiler has a heat transfer compartment above a combustion chamber which is divided by a horizontal partition inclined upwardly from the rear end of the boiler towards but terminating short of the front end thereof to provide a restricted port between the thus established upper and lower portions. An endless link belt establishes the lower portion of the combustion chamber and hot gas conduits extend from the upper portion through the heat transfer compartment to the exhaust and which is provided with a draft inducing fan and adjustable damper. Underfire air under the control of an adjustable damper is introduced into the lower portion of the combustion chamber upwardly through the belt and air jets are delivered into the combustion chamber through the front end both above and below the port. A standby fluid fuel burner is located in the rear end of the upper chamber portion.

Abstract: A self loading wood burning stove is provided and consists of a storage bin, a fire box and a conveyor for delivering automatically logs individually from the storage bin to the fire box.

Abstract: A stoking plant for fuel in whole bales, where the bales are conveyed on a transport tract (8) from a store and stoked in the whole condition into one of a number of combustion furnaces (2) with boilers (1), comprises a slide-gate (10) through which a bale transport carriage (5) can be filled with a bale of fuel. The transport carriage (5) then conveys the bale forward to the furnace (2) which is in need of fuel. When the bale transport carriage is positioned opposite the stoking door (4) of the furnace, a cover door (6) is released which is pressed against the carriage (5) by springs (13), a switch element is activated and the stoking door (4) is opened, and the bale is pushed into the furnace (2) by a piston (7). The piston (7) is withdrawn, but in such a manner that the furnace door (4) is closed before the cover door (6) is withdrawn to the start position. The bale transport carriage (5) is a tubular carriage which travels on running rails (9).

Abstract: A method and device in combustion plants for solid fuels with a movable grate means for feeding the fuel through the fireplace of the combustion plant, for the control of the fuel feed through the fireplace of the plant. To control that the fed fuel is completely combusted when discharged from the fireplace of the plant the degree of combusted fuel is sensed by a sensor means (9) in a zone (B) at the end of the movable grate means (1) in order to obtain a control signal to the drive means of the grate means.

Abstract: A control circuit for a stoker-fed heating system is effective, whenever the primary sensing control (thermostat or aquastat) of the system calls for heat, to determine whether there is sufficient fire in the furnace to assure maintained combustion, and if this is not the case, to shut the system down until combustion is again assured.

Abstract: A furnace for wood log fuel having apparatus which automatically inserts the logs into the furnace combustion chamber. The log fuel is retained in a sloping ramp storage compartment. Electrical circuitry controlled by a thermostat operates to move a log into an elongated chamber from which a motor driven injector pushes the log into the combustion chamber through a doorway covered by a flexible, segmented flap covering and also a door which is pushed open by the advancing log. The presence of the log on a spring mounted grate operates certain switches to return the injection mechanism to its ready condition and also to operate a fan which provides combustion air to the combustion chamber. The reduced weight on the grate by the consumption of the log by the fire permits the grate to move to a position to re-initiate the log injection cycle.

Abstract: This invention concerns an automatic feed device for a solid-fuel boiler, specifically for logs of wood. The subject of the invention is an automatic feed device for a solid-fuel boiler, specifically for logs of wood, characterized by the fact that it comprises: a loader (6, 6') having means (19, 66) for receiving a load of fuel (2) to be introduced into the boiler (1) and movable between a loading point for the said load and a point of dumping at the interior of the firebox of the boiler, means (24, 26) for moving the loader, means (29, 30) for controlling the opening of the door (4) of the boiler, means (36, 37) for controlling the dumping of the fuel (2) into the firebox at the end of the course of the loader, and means (44, 58) for detecting the state of combustion at the front of the grate (3) of the boiler, and for controlling the means for moving the loader.

Abstract: A furnace system for automatic, continuous and efficient burning of fragmented wood-type fuel incorporates a wood-type fuel combustion chamber, a fragmented wood-type fuel feeder or conveyor for trickle feeding fuel into the chamber at selected uniform rates, a heat exchanger or heat exchange plenum, igniter for igniting the fuel fragments supported in the combustion chamber, a flame sensor mounted relative to the combustion chamber for sensing the presence of flames from fuel supported in the combustion chamber, one or more blowers providing forced air or forced draft, and a control circuit for controlling and sequencing operation of the elements for the furnace system and for operatively coupling the flame sensor and igniter for switching off the igniter upon sensing of flames from the wood-type fuel.

Abstract: An automatic log feeder is provided which includes a hopper for retaining a plurality of logs. The hopper includes a plurality of generally parallel and vertically arranged compartments which are adapted to each hold a single row of logs. The hopper has a chute at its lowermost portion for dispensing individual logs onto a generally vertically arranged conveyor. The vertically arranged conveyor comprises an endless chain driven by a motor and a plurality of sprocket wheels, and a plurality of pairs of brackets which are foldably connected to the chain. Each of the bracket pairs is adapted to receive a single log from the chute. Additionally, the generally horizontally arranged conveyor is positioned beneath the generally vertically arranged conveyor and is adapted to transfer logs to a wood burning apparatus. The generally horizontally arranged conveyor comprises a motor driven push log for moving the logs in a horizontal fashion.

Abstract: A system for generating a dry coal weight signal is provided, wherein the moisture content of a coal feed to a solid fuel burner is determined, and the dry coal weight calculated on that basis. Moisture content is determined by measuring density of the coal being fed and/or the torque required to drive a head pulley about which the belt feeding the coal is led at a constant velocity. The dry coal weight signal can be communicated to the drive means, whereby the belt speed is accelerated or decelerated to maintain a constant supply of coal, on a dry weight basis, to the boiler. Also disclosed is a control system employing the dry coal weight signal for a plurality of control functions.

Abstract: A method and apparatus for controlling the burning of a solid fuel furnace is disclosed. In a furnace having a burning chamber, a fuel supply mechanism in the form of a rotating grate, a fuel discharge mechanism in the form of a rotating grate located adjacent the rotating grate of the fuel supply mechanism and at least one air blower, the present invention supplies a control mechanism for controlling the operation of the fuel supply and discharge mechanism as well as the blowers in such a manner that fuel is supplied and discharged in an optimum manner. The control mechanism senses the temperature of the combustion gases and the temperature of the load being heated by the furnace. If the temperature of the load is below a predetermined level and a first time period T.sub.1 has not passed since a preceding fuel supply and discharge, the fans are activated but a fuel supply and discharge cycle is not. If the time of the sensing of the low load temperature is below the time T.sub.

Abstract: An improved burning system for automatically controllably charging a wood-waste burning steam boiler utilizes a fuel bin unloader having a gravity fed screw metering device for feeding fuel into the system in response to steam demand and pollution output feedback signals. The metering device deposits fuel through a rotary air lock into an air stream of a fuel injection fan having a vortex controller on the inlet side to modulate and maintain a proper fuel-air ratio for wood firing. The fan injects the fuel and air into the boiler through a controlled proportioning valve. All controls and recording devices are contained in one control unit for operating each component of the system to achieve and maintain a proper fuel-air ratio according to received steam demand and pollution output feedback signals.

Abstract: A device for automatically dropping logs at a predetermined time for charging a fire laid on the bottom of a woodburning stove. The device includes a pair of elongated arcuate shaped log supporting members each of which is journaled within the stove adjacent a respective top side corner thereof. A latching system is connected to the log supporting member for releasably maintaining the log supporting members in a substantially horizontal supporting position. An electrically operated movable member is connected to the latching system for releasing the latching system upon being energized under control of a timing device at a predetermined time. As a result, the stove can be automatically charged during the middle of the night ensuring a fire in the morning.

Abstract: A forced air furnace includes a conventional fuel fired, primary heat exchanger and a secondary heat exchanger associated with the stack. The secondary exchanger includes a phase change material having a transition temperature within the range of the stack temperature, and which is disposed in heat exchange relation with the flue gases flowing through the stack. The secondary exchanger also includes duct means for conveying the circulated air in heat exchange relation with the phase change material; and the flow path through the secondary exchanger is an alternative path controlled by a damper. When the primary exchanger is turned on, the phase change material in the secondary exchanger is charged from the flue gases of the primary exchanger. When the phase change material is in condition to release stored heat, a temperature responsive control shuts off the primary exchanger and diverts the circulated air through the secondary exchanger.

Abstract: The arrangement includes a source of finely divided solid combustible material fluidized in an inert gas, and also a source of combustion-supporting gas, such as oxygen, air, or oxygen-enriched air. A gasifier is provided for gasifying finely divided solid combustible material by reacting the same with combustion-supporting gas, and the gasifier has one or more inlets. A first conduit connects the source of combustible material to an inlet of the gasifier. A second conduit connects the source of combustion-supporting gas to an inlet of the gasifier.

Abstract: A plurality of first logic processors are interconnected in a "ring" type network and individually exercise control over similar equipment group subsystems which individually contribute to the operation of an overall system. Each of the interconnected processors, in addition to its primary control function, monitors the safety of operation of the equipment group with which associated and the safety of operation of a "neighboring" equipment group. Redundant safety checks are thus performed on each equipment group and any discrepancies in the results of such safety checks are enunciated. A pair of further logic processors, in addition to performing other control functions including scheduling the operation of the individual equipment groups, redundantly check the safety of operation of the overall system.

Abstract: A refuse disposal system is disclosed including a combustion chamber, means disposed in the combustion chamber for supporting refuse to be burned, means for charging refuse on the support means, overfire means for supplying an increasing flow of combustion air above the support means as the temperature of the gaseous products of combustion increases above a first predetermined temperature, underfire means for supplying a decreasing flow of combustion air under the support means as the temperature of the gaseous products of combustion increases above the first predetermined temperature, override means for overriding the underfire means to decrease the flow of air under the support means when the temperature of the products of combustion decreases below a second lower predetermined temperature and means for reducing the rate with which the charging means places refuse on the support means when the temperature of the gaseous products of combustion increases above the first predetermined temperature.