Abstract: A dual stage combustion furnace has primary and secondary combustion chambers. The primary combustion chamber contains a solid fuel, such as wood or coal. The secondary combustion chamber is formed adjacent to and in communication with the primary combustion chamber for containing and igniting volatile combustion gases produced in the primary chamber. A plurality of hollow members, which provide a grate, extend through the primary chamber, and into the secondary chamber. Volatile gases given off in the primary combustion chamber are then ignited and burned in the secondary combustion chamber upon combination with heated air passing through the hollow grate members.

Abstract: The present invention provides a stove having the following features: a firebox for initiating the combustion of fuel, the firebox including a lower portion with a draft inlet therein; a first conduit disposed under the firebox for conveying combustion air to a draft inlet and for insulating the underside of the firebox; a secondary combustion chamber for receiving hot gases of combustion from the firebox and continuing the combustion; a second conduit which receives air from the first conduit adjacent the draft inlet and which conveys all the air which has not passed through the draft inlet along the periphery of the firebox and into the secondary combustion chamber, thereby increasing the flow of air through the secondary combustion chamber during periods of low combustion and for continuing the insulation of the firebox; and a third conduit for conveying the gases of combustion from the secondary combustion chamber to a flue.

Abstract: A solid fuel heating appliance in the form of a wood burning stove employs a combustor for oxidizing oxidizable species in the exhaust. A flame break is provided between the combustor and the combustion chamber of the stove to avoid impingement of flames on the combustor.

Abstract: A freestanding stove is provided including an elevated firebox mounted atop a tubular pedestal having a horizontally enlarged downwardly opening hollow base at its lower end. The firebox includes a combustion air inlet opening downwardly into the pedestal and the lower end of the pedestal opens downwardly into the hollow base which includes a damper for controlling the flow of combustion air from within the hollow base into the lower end of the pedestal. The base includes feet supporting the base a spaced distance above a horizontal surface upon which the feet rest and the feet are removable whereby the base may rest directly upon and over a horizontal support surface upwardly through which a combustion air opening is formed. The front of the firebox includes an openable transparent window equipped door and combustion air inlet passage structure for sweeping curtains of combustion air across the inner surface of the window from selected marginal portions thereof.

Abstract: A freestanding stove is provided including an elevated firebox mounted atop a tubular pedestal having a horizontally enlarged downwardly opening hollow base at its lower end. The firebox includes a combustion air inlet opening downwardly into the pedestal and the lower end of the pedestal opens downwardly into the hollow base which includes a damper for controlling the flow of combustion air from within the hollow base into the lower end of the pedestal. The base includes feet supporting the base a spaced distance above a horizontal surface upon which the feet rest and the feet are removable whereby the base may rest directly upon and over a horizontal support surface upwardly through which a combustion air opening is formed. The front of the firebox includes an openable transparent window equipped door and combustion air inlet passage structure for sweeping curtains of combustion air across the inner surface of the window from selected marginal portions thereof.

Abstract: Wood burning stoves are of a type having a lower chamber and an upper chamber interconnected by a port. Air inlets are located laterally of the base of a fire in the lower chamber with a natural draft therein effecting a multitude of upwardly rising air streams of which one type is hot and oxygen poor and which carry and heat another type of air stream which is oxygen rich. The port is so dimensioned and spaced in relation to the lower chamber and to the flue outlet of the upper chamber that a secondary combustion zone is provided in which the upwardly rising streams are suddenly contracted, expanded and intermingled with simultaneous heat loss minimized ensuring the maintenance of a temperature adequate to result in the combustion of pyrolitic products.

Abstract: A small compact stove capable of burning a variety of carbonaceous fuels has a base and located on the base is a vertically oriented cylindrical wall. The wall is formed of a heat conducting material and has open bottom and top ends. The interior surface of a portion of the wall forms a combustion chamber. A grate is located within the wall at the bottom end of the combustion chamber. The primary air chamber is located at the open bottom end of the wall and primary air is conducted through it and then up through the grate into the combustion chamber. A secondary air chamber surrounds at least a portion of the wall such that the wall forms one of the surfaces of the secondary air chamber. The wall includes a plurality of air passageways between the secondary air chamber and the combustion chamber such that air can flow within the secondary air chamber in contact with the exterior surface of the wall and be heated by heat conducted through the wall from the combustion chamber.

Abstract: A wood burning stove having improved air flow characteristics for effective combustion and purging of gaseous combustion by-products. A primary air inlet is provided below the loading door of the stove for feeding air to the firebox proper for combustion. A plurality of opposing supplementary air inlets are provided in opposite sides of the stove, at least two of the supplementary inlets being on the level of the primary air inlet, for introducing air into the firebox supplemental to the air flow through the primary inlet.

Abstract: The disclosure teaches a fireplace insert. The insert has a front surface having an openable see-through portion and fixed see-through portions on either side of the openable see-through portion. Warming air inlets are disposed below the fixed see-through portions, and combustion air inlets are disposed below the openable see-through portion. Bottom ducts are also provided, and each bottom duct has a front end and a rear end, the front ends being in communication with a respective one of the warming air inlets, the bottom ducts extending rearwardly horizontally behind the front surface. Cross ducts are one end thereof in communication with a respective one of the rear ends of the bottom ducts, and top ducts are disposed parallel to the bottom ducts and have front and rear ends. Pipe means communicate air from the bottom ducts to a respective one of the top ducts, and inverted L-shaped pipes, having front ends and rear ends, have the rear ends thereof connected to respective ones of the cross ducts.

Abstract: The invention concerns a grille for burning all sorts of solid fuels in ses, hearths, central heating boilers, baking ovens, combustion furnaces, drying kilns and others.The grille exists of two grilles fitted one above the other and in contact with one another, one of said grilles is movable with respect to the other, the width of each passage opening in one of the grilles is greater in the middle of the grille, permitting to close gradually from their ends the passage openings of the other grille during the displacement of one of said grilles.

Abstract: A stove for burning solid fuel such as firewood. a lower level air inlet opening is provided for so-called "primary air," and another air inlet opening is provided at a higher level for so-called "secondary air." The volume of air introduced into the stove from each inlet opening is separately controlled. An air metering means controls the amount of secondary air introduced into the stove through the higher level air inlet opening. The lower level air inlet opening and the air metering means both have a finite number of predetermined, fixed air transmitting conditions and no other air transmitting conditions. The lower level air inlet opening has preferably two predetermined, fixed air transmitting conditions--a maximum and a minimum. The air metering means has at least a predetermined, fixed maximum air transmitting condition and preferably also a predetermined, fixed minimum, transmitting condition. The level at which the two air inlet openings are located is specified.

Abstract: The invention provides a stove for burning a charge of fuel by primary air directed either above or underneath through the firebed. A firebed support is defined by an array of alternating fixed and movable bars, the movable bars having a length greater than their width when viewed endwise and being rotatable between a vertical attitude in which they permit upward passage of air and downward passage of ash through said support and a horizontal attitude in which they permit build up of a layer of ash at the base of the firebed. An air distribution chamber has an inlet for primary air, a first outlet from which primary air passes to a space above the firebed and a second outlet from which primary air passes to a space below the firebed. An air diversion flap is movable between positions in which air is selectively directed through the first and through the second outlet.

Abstract: A solid fuel furnace which includes a housing enclosing a firebox and a heat exchanger chamber. An open grate in the firebox supports solid fuel thereon. Combustion air is admitted to the area below the grate and is preheated and passes upwardly through the grate and fuel and mixes with volatile gases released from the fuel. The air/gas mixture is drawn downwardly through the fuel and exits the firebox through an inlet to an insulated burn-out chamber which is behind the firebox. A metal screen covers the inlet and serves to ignite the air/gas mixture. Hot flue gases exit the burn-out chamber to the heat exchanger chamber.

Abstract: The assembly is adapted for replaceable and operative installation within the opening of a standard fireplace. It comprises a combustion chamber and conduitry to accomodate ambient air entry into the chamber in a number of patterns and includes an arrangement for air preheating. Air is also heated by contact with the outside of the chamber and is expelled with mechanical assistance. Exhaust smoke is expelled through a baffle system in order to extract therefrom all useful heat.

Abstract: An outdoor furnace including a conditioned air chamber surrounding a fire box and having an air inlet and outlet connected to the space to be heated within the building. The furnace is characterized by a pre-heat chamber for the combustion inlet air as well as deflectors and baffles for maximizing contact of conditioned air flow over the fire box for maximizing the efficiency of the furnace. The furnace may also include an after-burner chamber and a damper for varying the degree of combustion within the after-burner chamber. The furnace also preferably includes an exhaust damper having a thermal control for exhausting excessively heated air from the conditioned chamber.

Abstract: A slow combustion stove having a transparent portion to enable vision into a primary combustion zone so that flames are visible in use has a double burning combustion chamber defined by the primary combustion chamber and a partitioned off secondary burning combustion chamber, an air inlet to enable air to circulate within the stove adjacent a deflector which deflects the incoming air over the transparent portion to cool and resist staining and soot build-up thereon. A majority of the air passes to the primary combustion zone and a proportion of further gases enter the secondary combustion chamber with the gases of primary combustion for combustion of smoke and other unburned gases.

Abstract: A thermostatically actuated arrangement for controlling opening and closing movement of the damper of a wood burning stove includes a duct arrangement extending through the combustion chamber of the stove between an air intake end opening through the stove housing at a location in the lower portion thereof and a discharge end opening through the stove housing at a location upwardly spaced from the intake end, for passage of ambient air through the duct arrangement for radiant heating thereof during burning of wood in the stove to create a continuous convective flow of heated air from the intake end to the discharge end, and a sensitive bimetallic spring disposed to receive the convective air flow from the duct arrangement at its discharge end and operably associated with the damper of the stove for actuating opening and closing movements thereof in response to decreases and increases in the temperature of the airflow.

Abstract: The wood burning water heating means of the present invention utilizes a firebox having a grate adjacent the lower end and a flue opening positioned downward from the upper end thereof. The flue extends into the firebox so as to deflect rising hot gases prior to their exit through the flue opening. A main draft opening provides communication of air below the grate to provide oxygen for the fire. A secondary draft opening is provided above the grate for introducing air in such a manner that oxygen will be provided immediately below the flue to facilitate combustion.

Abstract: A catalytic stove comprised of a housing having a fuel-burning chamber and an effluent chamber. The effluent chamber is separated from the fuel-burning chamber by a common wall. The wall is at the top of the fuel burning chamber and is inclined to form a cathedral or domed chamber ceiling. Air inlet ports are located in the fuel burning chamber and draft air is introduced to burning fuel at substantially the same rate from each port. The effluent from the fuel flows to a catalyst in the top of the fuel burning chamber. The effluent flows substantially directly from the fuel to the catalyst without undersirable eddying thereby preventing the effluent from cooling and condensing into creosotic droplets. The catalyst assists in burning an increased percentage of the flue gases. An air diffuser is provided contiguous to the catalyst and provides an air mix with the effluent from the burning fuel to further facilitate oxidation in the catalyst.

Abstract: A control regulates the rate of flow of combustion air flowing into an airtight stove or furnace10 containing a fire. A control element 15 or 45 is arranged in communication with the air inflow stream and moves in response to the velocity of the flowing air. The control element 15 or 45 moves to constrict the area of the inflow stream as air velocity increases and to open the area of the inflow stream as air velocity diminishes. Springs 25 and 26 or 60-62 bias the control element toward a maximum opening, and the spring bias is non-linear to provide increasing resistance to movement as the control element approaches a closed position. The spring bias system is preferably adjustable to vary the air inflow rate that is otherwise kept steady by the control element.

Abstract: The door handle of a heating unit is cooled by providing a duct traversing the interior of the handle from exterior of the firebox of the heating unit to the interior of the firebox. The induced flow cools the handle and provides cool air in the firebox to trap and maintain the hot gasses closer to the fire for a more complete combustion. An open, ellipsoid, spiral coil surrounds the grip of the handle.

Abstract: A solid fuel burning heater with improved efficiency in burning logs. A housing is divided by a louvered internal wall into front and back sections having combustion and heating chambers respectively. The louvered wall terminates below the top of the housing providing a crossover space through which hot, combusted gases flow from the combustion chamber to the heating chamber. A vertical heat transfer duct extends through the top and bottom of the housing and has open ends in free communication with external ambient air. Front and rear flues are connected to the combustion and heating chambers and these are interconnected by a main flue leading to a chimney. A damper is provided in the front flue. The combustion chamber comprises a primary combustion zone on a fuel-supporting grate and a secondary combustion zone above it. Adjustable draft openings at the front of the housing control air input to the combustion zones.

Abstract: A stove, particularly adapted for burning wood, includes a system for delivery of air to the combustion chamber which features a plurality of elongated headers arranged to deliver air relatively uniformly along the entire length of the combustion chamber.

Abstract: A wood burning stove with a catalytic combustor and combustor bypass structure to increase fuel-burning efficiency and safety by reducing creosote emission by the stove and to provide for safe stove operation even if the catalytic combustor becomes blocked, clogged or otherwise obstructed. The single and multiple bypass structures disclosed utilize bypasses located adjacent to the catalytic combustor or combustors to provide for efficient operation with relatively little smoke flow through the bypass during normal operation and with at least partial combustion of smoke which does bypass the combustor. A smoke relief door automatically actuated by opening the fuel loading door to prevent smoke spillage into the room is also disclosed together with alternative means for supplying secondary air to the stove's combustion chamber in the vicinity of the catalytic combustor.

Abstract: Convected air from the room to be heated enters two first air spaces (10) through two front inlets (12) and circulates through passageways (13) between inner and outer casings forming the fireplace and re-enters the room through front air outlets (14). Cold fresh air from outside the room enters a second air space (14), between the two first air spaces (10), and can be fed into the room through a control vent (16) for promoting combustion within the fire and/or can be fed into the first air spaces (10) so as to supplement the convected air flowing through the passageways (11).

Abstract: A combination furnace including a solid fuel burning section and an electrically powered heating section. The two sections are disposed within an upright, insulated casing. A heat exchanger is provided above a fire box which constitutes the fuel-burning section. Dampers control the flow of combustion air to the fire box and the heat exchanger.

Abstract: A stove apparatus which is designed to achieve relatively complete combustion of solid fuel such as wood or coal. A combustion chamber is defined by a connected wall housing and includes a primary flue opening at an upper rear portion thereof. Primary combustion air enters into the forward portion of the combustion chamber and the resultant combustion gases are deflected from normally passing to the chimney via the primary exit flue by means of a downwardly extending baffle which creates an increased temperature exit zone adjacent thereto. A device for introducing secondary combustion directly into said exit zone is provided so as to insure more complete combustion and reduce the amount of tars, i.e., creosote, produced in the combustion process. In addition, an unique device for regulating the amount and the combustion chamber is provided.

Abstract: A free standing stove is provided which includes a firebox for initiating the combustion of fuel, and a secondary combustion chamber for continuing the combustion. A first conduit is provided for conveying air through a draft inlet damper and into the firebox. A second conduit is provided for conveying air into the secondary combustion chamber. A third conduit conveys the gasses of combustion from the secondary combustion chamber and out of the stove. A fourth conduit may also be included which would be mounted in thermal contact with the third conduit, the fourth conduit including a lower end and an upper end and being adapted to receive ambient air in its lower end and warm the air prior to discharging it out of the upper end.

Abstract: A stove firebox has a longitudinal opening in its bottom wall in which is supported upper and lower grates. The lower grate is slidable relative to the upper grate. Each grate has longitudinally spaced cross bars, and such cross bars and the openings therebetween have the same longitudinal dimension whereby upon offsetting the cross bars of the two grates longitudinally, an imperforate floor is provided and upon alignment of the cross bars, vertical passages are formed to sift ashes downward for cleaning the firebox. The slidable grate can be reciprocated to provide the sifting step. An interior draft inlet is provided at the bottom of the firebox adjacent the front.

Abstract: A heat exchanger furnace includes a firebox, a heat exchanger housing in communication with the firebox for receiving combustion gases therefrom, and a plenum housing surrounding the heat exchanger housing so as to define a plenum chamber therebetween. A plurality of baffles are supported in vertically spaced apart relation within the heat exchanger housing, which baffles include peripheral edges disposed in clearance relation from the housing sidewalls whereby hot combustion gases rising within the heat exchanger housing are directed outwardly adjacent the heat exchanger sidewall for increased heat transfer to the plenum chamber. Exhaust tubes at the top of the heat exchanger housing may be directed through the plenum chamber for providing additional heat transfer surfaces therein. The firebox may have a frusto conical shaped sidewall whereby the combustion surface area may be adjusted with the level of fuel in the firebox.

Abstract: The catalytic creosote burner comprises a nest of metal plates spaced so that flue gas can flow between the plates. The plates are coated with a catalyst for burning creosote. The plates converge in the direction of the gas flow. There is an advantage in this configuration of converging plates. The frontal area of the burner that faces the fire is increased, so that the burner receives additional heat by radiation from the fire. The frontal area that faces the flue is reduced so that less heat is lost by radiation from the burner. As a result, the burn up of creosote is higher than when the plates are parallel, at the original inlet spacing.

Abstract: A housing is provided defining a closed lower combustion chamber and a closed upper afterburn chamber disposed immediately above the combustion chamber with one marginal portion of the combustion chamber projecting horizontally outwardly beyond the corresponding marginal portion of the afterburn chamber. A combined flue gas and bypass chamber is disposed above the one marginal portion of the combustion chamber and is horizontally registered with the afterburn chamber. Partition structure divides the combined flue gas and bypass chamber into central and remote end portions spaced along the aforementioned one marginal portion and a pair of first ports communicate the remote portions with adjacent underlying upper portions of the combustion chamber, a pair of second ports communicate the remote portions with adjacent portions of the afterburn chamber and third port structure communicates the central portion of the afterburn chamber with the central portion of the combined chamber.

Abstract: A heater closure attachment for 30 and 55 gallon metal drums which includes a main closure section provided with an exhaust stack and two depending draft inlet pipes, and a hinged section through which solid fuel is inserted, the inlet draft pipes having damper lids to control combustion and the whole attachment being in knock-down, readily portable form for assembly on the job by unskilled labor.

Abstract: A thermostat for a stove is disclosed. The thermal control unit is contained in a housing which has an aperture formed therein and includes a thermal control unit for detecting changes in the temperature of the stove. A flap is secured to the housing and is rotatable across the aperture so as to cover the aperture to any desired degree. The thermal control unit controls the position of the flap to control the effective area of the aperture, thereby to control the amount of air supplied to the stove. The thermal control unit, the flap and the aperture cooperate to ensure that the effective area of the aperture changes by an amount approximately proportional to the square of the magnitude of any change in the stove temperature detected by the thermal control unit. The thermal control unit may preferably comprise a bimetallic coil or a liquid expansion thermometer.

Abstract: The present invention is directed to the provision of an improved stove insert for a fireplace opening, having means associated therewith for precisely controlling draft, thereby enabling the stove insert to be used for coal as well as wood.

Abstract: A stove (10) for burning combustible solid fuels (64) comprising an enclosed firebox (16), a baffle (54) dividing the firebox into a lower combustion chamber (18) and an upper chamber (20) spaced from the front wall (36,46) of the firebox to permit combustion gases to flow from the combustion chamber into the upper chamber, a door (24) for facilitating introduction of solid fuel into the combustion chamber, an outlet flue (48) communicating with the upper chamber for withdrawing combustion gases from the firebox, a viewing window (38) in a wall of the firebox for enabling the fire to be viewed without opening the door of the firebox, an air inlet (72) for admitting a flow of air into the firebox and means (84) for splitting a flow of air admitted through the air inlet into first and second portions and for directing the first portion toward the bottom of the combustion chamber and the second portion into a stream of hot combustion gases passing from the combustion chamber to the upper chamber; a shroud ( 50)

Abstract: A wood-burning stove includes side walls joined together in an airtight manner to form a firebox and a heat chamber thereabove. The firebox contains upstanding rails to support wood logs for combustion. Streams of heated air are discharged from a manifold that extends from rail-to-rail outwardly from one terminal end of each rail between opposite side walls of the stove. A plate is adjusted to control the flow of air into the manifold. An access door has openings in a spacer side wall for supplying air as desired to the firebox. The spacer walls of the door support a glass panel at an outwardly-spaced location from a deflector to prevent deposits of creosote and other materials on the glass.

Abstract: A rectangular stove structure has a stepped top with a sloped intermediate top portion having heated air outlets. Room air is passed through U-shaped ducts arranged along the inside surfaces of the stove side walls, and firebrick is provided on the floor of the stove structure between these ducts. Air is drawn into the ducts through a side opening which may have a blower and conduit assoicated therewith. The door of the stove has rotary combustion air inlets, and a baffle plate is provided inside the door to provide primary air for the fire, and secondary air for improving air circulation and ventilation inside the stove. Domestic hot water can be heated at the rear of the stove structure in an annular chamber defined for this purpose at the connection for the exhaust gas flue. Domestic hot air can be supplemented by a plenum provided on the lower front top, and the plenum receives heated air from the outlets in the sloped intermediate top portion.

Abstract: A solid fuel burning modular stove fabricated from a plurality of metal assemblies includes a first assembly provided with a combustion chamber, an air duct at the lower front of the chamber communicating with the ambient air, a louver member inside the air duct varying the degree of admittance of air through the duct, flue pipe means for exhausting combustion products from the stove, a plurality of fire brick lining the floor, rear and side walls. Vertical ducts are positioned along the rear and side walls having inlet openings at their bottom and outlet openings at their tops, heated air rises through the ducts and discharges into the ambient air. A second assembly to be attached to the bottom of the first assembly comprising horizontal channel means in communication with the vertical duct inlets providing a blower to force outside air through the vertical ducts.

Abstract: A solid fuel-burning stove has a fire chamber defined by its walls and top and an upper gas recirculating chamber with a convex portion is provided in the top section of the stove.

Abstract: An insert for a stove permits efficient burning of either coal or wood and includes a movable grate. Granular material is located around the insert for modulating the heat transferred to the stove walls from a fire on the grate. Bumps project upwardly from the grate to facilitate jostling of coal to remove ash from that coal.

Abstract: A freestanding stove is provided including an elevated firebox mounted atop a tubular pedestal having a horizontally enlarged downwardly opening hollow base at its lower end. The firebox includes a combustion air inlet opening downwardly into the pedestal and the lower end of the pedestal opens downwardly into the hollow base which includes a damper for controlling the flow of combustion air from within the hollow base into the lower end of the pedestal. The base includes feet supporting the base a spaced distance above a horizontal surface upon which the feet rest and the feet are removable whereby the base may rest directly upon and over a horizontal support surface upwardly through which a combustion air opening is formed. The front of the firebox includes an openable transparent window equipped door and combustion air inlet passage structure for sweeping curtains of combustion air across the inner surface of the window from selected marginal portions thereof.

Abstract: A stove having automatic chimney air flow compensation for reductions in air flow to its combustion chamber is disclosed. An increase or decrease in compensatory air flow is dependent upon the movement of ganged dampers. The amount of compensatory chimney air flow is dependent upon the size and/or position of apertures and blocking portions formed respectively in the ganged dampers. The dampers can be configured, as appropriate, and thereby tuned, to be particularly responsive to local conditions.The stove is provided with a conduit positioned to provide a source of fresh air. The conduit is clamped to the stove to heat the air flowing therein and thereby prevent exhaust gas condensation and creosote buildup when it rises in and from the chimney.

Abstract: The wood burning heating means of the present invention utilizes a firebox having a grate adjacent the lower end and a flue opening adjacent the upper end thereof. A baffle is positioned immediately below the flue opening in such a manner as to deflect rising hot gases prior to their exit through the flue opening. A main draft opening provides communicaton of air below the grate to provide oxygen for the fire. A secondary draft opening is provided above the grate for introducing air in such a manner that oxygen will be provided immediately below the baffle to facilitate combustion of the gases which have accumulated adjacent the baffle.

Abstract: The combination stove has a fire chamber that is partially cylindrical including a side loading door for loading wood or other combustible material such as coke or coal into the fire chamber. The front of the stove may be opened to enable viewing of the wood or coal burning in the stove by means of an arcuate sliding door that is operable to substantially totally close the chamber or open a section of the front thereof for viewing purposes. The sliding door is covered by a window construction including a tempered glass face. The stove is provided with an open base for supporting the chamber in a shroud covering the top and back of the chamber, preferably including blower means associated therewith. Particularly for wood combustion, the chamber is provided with a top draft extending longitudinally of the chamber and has supported therein a grate.

Abstract: A slow combustion stove is disclosed. The stove comprises a stove body adapted to receive fuel, such as wood, on the bottom to form a fire bed, an adjustable air intake for admitting air into the stove body, an exhaust duct, a smoke outlet located adjacent the top of the furnace body and communicating with the exhaust duct, a smoke flue located adjacent the bottom of the furnace body and also communicating with the exhaust duct, and damper means permitting exhaust of the combustion gases through the smoke outlet during starting of the fire and through the fire bed and the smoke flue when the fire is well lit to ensure maximum fuel and gas combustion.

Abstract: A sustained ignition secondary combustion apparatus in a housing of refractory insulating material includes a first level for conducting secondary air through a secondary air inlet and channel, and a second level for conducting smoke products. A partition separates the levels or zones. Openings are provided in the partition between the levels bounded by a high temperature porous or fiberlike material in the form of igniter tube elements. Secondary air and smoke products diffuse into the interstices of the porous or fiberlike material where contact and combustion maintains the igniter tubes at or above the ignition temperature. Ignition and secondary combustion of smoke products in the second level is therefore sustained and secondary air is preheated as it passes through the openings. A secondary combustion zone is defined in the region of the openings between the levels and continues down stream through the exhaust outlet.

Abstract: A heating device for consuming a combustionable fuel, having an internal combustion chamber with top, sides, ends, and a grate forming the bottom; an outer shell, having a top, sides, ends, and a bottom in spaced relation below the grate; a primary air supply adapted to distribute the air beneath the grate; a secondary air supply adapted to preheat the secondary air prior to entering the combustion chamber at a location above the grate; an axis door in one end suitable to pass fuel within the combustion chamber; an exhaust chamber between the combustion chamber and the outer shell adapted to extend across the top and at least partially down a side in fluid communication with the combustion chamber; an exhaust port adapted to exhaust the combustion gases from the exhaust chamber externally of the device; a damper adapted to selectively divert exhausting gases in the exhaust chamber at least partially down one side, to extend the distance travelled by the exhausting gases to improve secondary combustion and the

Abstract: A wood-burning stove utilizes a volatilization chamber inserted within the combustion chamber of the stove. The volatilization chamber contains a charge of wood which is heated to drive off combustible gases and vapors. The combustible gases and vapors are thereafter burned in the combustion chamber of the stove by being passed through a layer of solid fuel w hich includes a substantial amount of charcoal residue from previous volatilized wood. The heat generated by burning the volatile material is used to produce additional volatiles as well as to heat the stove.

Abstract: An improved wood burning stove for providing heated air to a room or similar area includes an enclosed fire chamber, a hearth at the bottom of the fire chamber, draft inlet means at the front of the fire chamber and a flue at the rear of the fire chamber. Within the fire chamber is an enclosed air chamber having lower and upper portions; the lower portion communicates at the bottom of the stove with the ambient air and extends upwardly adjacent the rear wall of the fire chamber to a point below the flue, where it joins with the upper portion. The upper portion of the air chamber extends upwardly toward the front of the fire chamber at an acute angle with the horizontal, preferably between five and twenty-five degrees; at the forward end of the upper portion the air chamber communicates with one or more air pipes which extend to the front of the stove and there open to the ambient air.