Abstract: A downdraft stove with a conical reaction chamber surrounded by a heat-insulating mass is disclosed. A tubular grating installed in the reaction chamber has a substantially vertically oriented central tube open at its upper end and connected at its lower end to an air inlet opening, and a cap supported above the open upper end, the space between the cap and the upper end constituting a primary air inlet nozzle. A plurality of grating tubes are radially distributed around and take off substantially horizontally from and communicate with the central tube, thereby defining a grating, and then turn downwardly into a conical shape conforming to the reaction chamber shape and are open at their downward ends to thereby constitute secondary air inlets. The downward-projecting ends of the grating tubes are twisted about the axis of the central tube in order to induce a swirling air flow pattern in the reaction chamber.

Abstract: A fireplace accessory serves as a combustion efficiency improvement device. The structure is a tubular element open along a front side and in the form of an arch lying upon its side for partially enveloping logs or other fuel. A horizontal combustion region is provided within the structure for at least partial exposure of the fuel through the frontal opening by the structure, the frontal opening facing toward a room area to be heated by the burning fuel. The arch configuration both cradles the fuel and insulatively and radiantly encloses it. A double-walled configuration, preferably curved stainless steel sheets with thermally insulating, refractory material between them, defines an interior surface which becomes heated to and is maintained by the combustion at extraordinarily high temperatures.

Abstract: A stove for burning combustible solid organic material, such as wood. The stove has a vertical fuel chamber with a combustion zone in the lower portion of the fuel chamber which is defined by an air inlet passage across the width of the fuel chamber and a convergent outflow passage at the bottom of the chamber. The combustion zone is shaped to provide a wedge-shaped area of incandescent coals during combustion in the combustion zone. No grate or other retention apparatus is needed in addition to the convergent outflow passage in order to retain fuel in place as it is consumed. The stove may be configured to provide radiant heat, as a forced air furnace, or as a boiler, or any combination of the three.

Abstract: An improved grate and method for burning solid fuel having a support for the fuel, a fan, a multiplicity of preheated air jets uniformly distributed across the entire area of the grate and directed through the support generally upwardly into the lower burning surface of the solid fuel, and a trough for collecting a layer of glowing coals located immediately below the jets and in close proximity to the burning lower surface of the solid fuel. The grate provides the cleanest burning and lowest fuel consumption occurs when only one layer of solid fuel is placed on the grate.

Abstract: A downdraft furnace comprises a combustion component associated with a heat exchange component. The combustion component includes a fuel chamber, a primary combustion chamber and a secondary combustion chamber operatively interconnected by a constricting throat opening. Log support structure is provided to carry split logs and at an angle of approximately thirty degrees from the horizontal. The support structure and the logs define a primary air flow passage directed toward the throat opening through which primary air flow is directed at the bottom portions of the fuel segments. The inlet includes closure means to restrict and vertically vary slightly the path of primary air flow. Passage means are provided to introduce secondary air directly at the throat opening. The inlet includes closure means to restrict and vertically slightly vary the path of primary air flow.

Abstract: This invention is for a stove having a cylindrical body with holes circumferentially disposed on the sides thereof and which holes gradually increase in number and in size towards the top thereof. The cylindrical body has an open top and a bottom wall and supported by legs at the bottom thereof. Disposed within the cylindrical body and spaced from the bottom wall are vertically spaced apart plates, the upper of said plates being perforated and both plates are connected to a central downwardly extending short cylinder communicating with the space above the bottom wall which has primary inlet openings with an adjustable rotatable plate for opening said primary inlet opening. Resting on the short cylinder is the vertical cylindrical screen, and at the top of said cylindrical body is a cover which has a flame opening defined by a short upwardly and downwardly protruding short cylinder. At the bottom of said cover is suspended a fuel top shield with a central opening.

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: This invention is a non-fossil fuel fired hot water system which allows a large amount of water or other liquid to be raised to a relatively high temperature, but below the boiling point, in a relatively short period of time. Due to a unique air circulation system, extremely high temperatures of the combustible material can be obtained with secondary burning eliminating all visible particulate material from the exhaust stack of the system. The unique firebox itself is disposed such that it is surrounded by water on all sides including the access closures for said firebox.

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: An improved grate block includes a blow-out channel terminating at a blow-out opening through the face of the block, the opening having pre-determined dimensional relationships with respect to the size of the front face of the block. The ratio of the width to the height of the front face is smaller than the ratio of the width to the height of the blow-out opening, and one-half the area of the front face is between 20 and 40 times larger than the cross-sectional area of each blow-out opening. Additionally, the blow-out openings are arranged above the horizontal center line and laterally spaced from the vertical center line through the front face, the channel sloping at an angle relative to the upper surface of the grate block which lies between about 15.degree. and about 25.degree..

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: There is described a device formed by a number of hollow elements mounted next to one another and fastened to one another, which have such a profile that they form at the bottom in the horizontal portion thereof, a grate the fuel bears on, merge backwards into a wall and form at the top, horizontal or substantially horizontal vertically or lateral evacuation pipe(s).

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 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 fireplace or stove apparatus for efficiently providing heat to a structure without loss of interior air to the flue draft. A blower forces outside air through a conduit located in the exhaust flue into a grate located in a fireplace or stove. The fuel loading opening of the fireplace or stove is made substantially air-tightly sealed. An air opening in the grate provides air to be consumed by the fire. A second air opening in the grate is fluidly connected by means of a conduit to the structure to be heated.

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: 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 furnace for burning dry or wet wood waste products such as hogged bark and the like is provided with a grating therein comprised of aligned rows of bricks resting on supporting cross beams, with at least some of the rows of bricks maintained a uniform distance from other rows of bricks by spacers disposed between such spaced-apart rows of bricks. The furnace is charged by turbulent air entering both above and below the grating, with a select portion of such air being pre-heated. A temperature gradient is established between an area immediately beneath the grating and the area above the grating in the range of 2200.degree. F. and can be controlled by selected initial placement of the bricks and spacers to achieve an optimum cross sectional area for flow of heated, turbulent air through the grating to produce a temperature for efficient heating, drying and burning of wood waste products in an essentially pollution-free manner.

Abstract: A wood burning stove comprises a fire chamber of which the upper part is constituted as a heat exchanger. A primary air supply is provided as is a secondary air supply, the secondary air supply permitting air to be mixed with the gaseous products of combustion to support complete combustion of those gaseous products. Both air supplies have dampers, the damper of the secondary air supply being automatic and opening as the damper of the primary air supply is closed. The secondary air supply comprises an inlet manifold interconnecting a plurality of tubular elements which form a fire supporting grate, the tubular elements leading the secondary air beyond the fire to a region in which mixing of that air with the gaseous products of combustion is effected, secondary air passing through the tubular elements being preheated by the burning fuel supported on the grate.

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 solid fuel heater comprises a plurality of horizontal tubes defining between a vertical partition and an opposed vertical wall of the heater, a tubular grate with given ones of the tubes connected to a primary air source manifold header while others are connected to a secondary air source manifold header for preheating the air. The ends of the tubes opposite the connection to the headers open, respectively, to the upper side of the tubular grate for delivery of primary air and to the lower side for delivery of secondary air. The vertical partition wall forms a hot air passage for a downdraft operation leading to the stack. Preferably, a secondary grate underlies the tubular grate. By operating in a downdraft manner, only the lower ends of the solid fuel are burned, permitting low stack temperatures and long burning operation of the heater whether wood or coal fired.

Abstract: A high efficiency, air-tight wood stove having a firebox with front, side, rear, top and bottom walls, primary air introducing means for admitting combustion air into the firebox, air flow means adjacent the bottom of the firebox for directing a flow of air upwardly across at least one firebox wall, at least one supplemental air inlet for diverting a portion of the air from the air flow means into the firebox, fan means for forcing air through the air flow means and through the supplemental air inlet, the size of the primary air introducing means being chosen to automatically restrict the combustion in the firebox if the fan means stops to maintain the temperature of the stove and surroundings at safe levels.

Abstract: An efficient, clean burning, woodburning stove in which super heated fresh air and exhaust gases from the primary combustion of the wood fire are introduced into a secondary combustion chamber wherein these gases are mixed to recombust remaining fuel particles. Exhaust from the secondary combustion chamber enters a heat exchange chamber wherein the heat content of the exhaust gas is transferred to the cooking surface of the stove. The burning rate of both the primary and secondary combustion can be independently controlled by individually selecting the air supplies to the combustion areas. An inclined grate, in combination with the direction of the exhaust gases, provides a self feeding feature in which an even burning rate of the fire is insured.

Abstract: A solid fuel furnace includes a combustion chamber and an elongated grate trough extending below the combustion chamber for charging the solid fuel into the chamber. A tube extends within the grate trough so that the axis of the tube is parallel to that of the trough, the tube being supported at the ends of the chamber for rotation about the tube axis. Blade members are provided on the outer circumferential surface of the tube to convey the solid fuels introduced into the furnace in the axial direction of the tube as the tube is rotated. The blade members have radially extending openings which communicate with the interior of the tube, and combustion air is supplied to the tube interior at one end of the tube so that the combustion air is introduced into the combustion chamber through the blade members as the tube rotates. Accordingly, both solid fuel and combustion air are charged into the combustion chamber at a desired rate by the rotating tube and blade members.

Abstract: Disclosed herein is an improved wood burning stove employing a combustion chamber and a flue for removing exhaust therefrom and also a catalytic converter means for oxidizing oxidizable species in the exhaust. A passageway is provided for bypassing the exhaust around the catalytic converter means, the passageway being controlled by a bypass damper for controlling access to the passageway for varying impedance otherwise presented to the exhaust by the converter, for example, during the addition of fuel to the stove. Such an arrangement minimizes back pressure caused by the converter means.

Abstract: A fireplace grate includes a generally air-impervious fuel support plate with an upstanding front rim. Doors slide along the outer face of the front rim to control the main flow of air to the fuel through these front rim openings. The fuel-support plate includes central slotted openings for screening ashes from the fuel and supplying draft for efficient burning at both ends of the grate. A removable cover blocks these openings when burning logs directly above to prevent a bottom draft against burning fuel, which results in less efficient burning and possible overheating of this section of the grate.

Abstract: A wood burning stove having a primary combustion chamber and a secondary chamber having a catalytic converter therein is disclosed. Primary air is introduced to said primary chamber and secondary air is introduced to said secondary chamber utilizing completely separate and independent control means, with the draft means for said primary and secondary air both being located below the fuel (wood) support level. Means are provided for preheating both the secondary air and the catalytic converter.

Abstract: A grate bar for a furnace grate lining is disclosed. The grate exhibits lateral contact surfaces and external ribs on its lower side in the vicinity of the contact surfaces. At least one jet-like air channel is in part formed by a recess in at least one lateral contact surface between adjoining grate bars.

Abstract: The invention discloses an apparatus for maximizing the uniformity of distribution of gasification medium in a rotary grid generator. To insure proper input, a distribution head is rotatably mounted within the interior of the rotary grid, and the distribution head is connected by means of elastic input conduits to either openings which are directly connected with the reactor chamber, or to distribution chambers in the individual segments of the rotary grid. Through use of the apparatus, the formation of canals through preferential gas flow in the solid beds of pressure gas generators is eliminated.

Abstract: A furnace for burning dry or wet wood waste products such as hogged bark and the like is provided with a grating therein comprised of aligned rows of bricks resting on supporting cross beams, with at least some of the rows of bricks maintained a uniform distance from other rows of bricks by spacers disposed between such spaced-apart rows of bricks. The furnace is charged by turbulent air entering both above and below the grating, with a select portion of such air being pre-heated. A temperature gradient is established between an area immediately beneath the grating and the area above the grating in the range of 2200.degree. F. and can be controlled by selected initial placement of the bricks and spacers to achieve an optimum cross sectional area for flow of heated, turbulent air through the grating to produce a temperature for efficient heating, drying and burning of wood waste products in an essentially pollution-free manner.

Abstract: An indoor barbecue cooking device comprises a grill and a removeable oven cover so that the device can be used either as a barbecue grill or a barbecue oven. The device includes an electrically powered air blower which is selectively and automatically activated by either a thermostat or a photocell. When the device is used as a grill, the blower is automatically activated in response to the detection of an open flame by the photocell to blow the flame out so that the food is prevented from being burned. When the device is used as an oven, the blower is automatically activated by the thermostat when the selected temperature is exceeded, so that cooling air is blown into the oven to maintain the selected temperature.

Abstract: The present invention relates to air-cooled grate bars, in particular for mechanically conveying mechanical grates such as pivot step grates, comprising a cap of U-shape which is provided over the respective grate bar and is in particular welded on and which forms with the grate bar disposed therebelow passages extending longitudinally of the grate bar, the cap being led at the bearing-side end of the grate bar up to shortly before the curvature end and the cap and thus the passages being in each case sealed at the end face at the curved cap end.

Abstract: A fire grate for holding particulate carbonaceous fuel such as sawdust and powdered coal consisting of stepped horizontally disposed and vertically spaced concentric grate members having center openings and defining a pyramidal structure. The grate is enclosed by the fuel which, by virtue of the stepped arrangement of the concentric grate members, is prevented from freely falling through the spaces between adjacent grate members.

Abstract: A fluid heating system specifically designed for the use of solid bulk fuel, such as wood or the like. The burner unit includes a continuous coil of fluid carrying conduit which acts both as a grate for supporting the fuels of combustion and as the primary implement for circulating fluids in close proximity to the combustion material so as to maximize the heat absorption by the fluid. Primary and secondary combustion air inlets combine with a baffling system that maximizes the efficiency of the combustion process within the heat transfer coil. Room heating and hot water storage apparatus are also disclosed as desirable end uses for the heated fluid.

Abstract: A primary combustion chamber is located above a secondary combustion chamber with a support grate between the two for supporting particulate solid waste fuel to be burned efficiently. Primary air is introduced to the primary combustion chamber with secondary air introduced below the grate into a combustion gas flow to cause complete burning in the secondary combustion chamber. A brick wall screen means of high temperature, corrosion-resistant brick forms the secondary combustion chamber to allow exhaust gaseous product to exit therethrough while screening out ash which can be removed from the combustion area. The gaseous product passed through the screen is then passed to a heat exchanger to utilize part of the heat produced for heating primary and secondary air used in the combustor. The exhaust gas from the heat exchanger can then be put to use in a boiler or other energy producing device.

Abstract: A grate assembly consisting of a pair of tubular U-shaped grates with turned-down, front positioned ends coupled to receptacles in a base plate, which base plate extends across the front and inside of a fireplace. Two of these receptacles, one coupled to each grate, are connected to a blower positioned in a frontal cavity of a hearth in front of and below the fireplace. The other two of the receptacles, one connected to each grate, are connected to pipes which extend down through and to the front of the hearth. They exhaust heated air.

Abstract: A grate for industrial furnaces wherein each row of grate bars includes alternating stationary and reciprocable bars. The stationary bars which flank a reciprocable bar are connected to each other by a bolt which extends transversely of the stationary bars and of the reciprocable bar therebetween and has hook-shaped end portions or screws engaging the inner sides of ribs forming part of the stationary bars and adjacent to the respective side of the reciprocable bar. The median portion of the bolt extends through elongated slots in the ribs which are provided at the underside of the reciprocable bar. The latter moves with respect to the bolt and with respect to the adjacent stationary bars.

Abstract: A draft control is described for selectively admitting exterior fresh air to assist combustion within the interior of a fireplace. The draft control is comprised of two interconnected and relatively slidable plates. The plates are dimensioned relative to a standard firebrick to facilitate installation in existing fireplace structures. Cool, exterior air is allowed to pass through selectively aligned apertures extending through both plates into the firebox. The plates may slide between this operative position wherein the apertures are in open contact and a closed position wherein the apertures of one plate are out of alignment and do not permit free passage of air into the fireplace interior.

Abstract: A tray has an upturned flange at least on the front edge thereof, and support means to space the tray above the floor of a fireplace, such that an opening is provided under the front of the tray to permit air flow. A hollow, raised portion in the tray, or draft control, has orifices that permit a controlled flow of air to fuel in the tray. The tray is closely fitted to the walls of a fireplace; so that, substantially, the only source of oxygen for the fuel in the grate is through the orifices in the draft control. In a preferred embodiment, the draft control is removable and fits over an opening in the tray. Also, valve means may be included for closing the draft control to any desired extent.

Abstract: A fireplace draft device introduces outside air along the front edge of the fireplace firebox and the induced air is so distributed that the major portion of air flow is adjacent the ends of the front edge thereby encouraging more uniform burning of the fireplace fuel. The draft introducing device is also provided with means which cooperates with the conventional fireplace damper to control the volume of induced air.

Abstract: A forced air circulation heating unit is formed of a U-shaped conduit placed on the floor of the fireplace and a fan forcing air through the conduit to be heated in the fireplace and projected into the room. Jets are provided on the conduit to direct streams of air from legs of the conduit toward a base joining the legs in order to completely burn fuel thereby reducing carbon monoxide, to facilitate starting of a fire and to reduce smoking. The base of the conduit has an increased cross-sectional flow of air and the jet streams cooperate with the base to assure that the hottest part of the fire is produced by coals on and adjacent the base thereby increasing heat obtained from the unit and saving fuel.

Abstract: A furnace and method of operation are disclosed for the efficient, controlled combustion of a combustible material such as wood, coal, etc. The furnace includes a grate which grate permits a large amount of combustible material to be stacked within the grate and to be constantly compressed to insure efficient combustion. The furnace also includes a heat exchanger surrounding the grate, which heat exchanger is comprised of an intake jacket and an exhaust jacket disposed on opposite sidewalls of the furnace. The heat exchanger also includes a plurality of heat exchange tubes disposed above and behind the grate and connecting the jackets. Air is drawn into one of the jackets, is directed through the heat exchange tube where the air is heated, and is exhausted through the other jacket. A portion of the heat exchanger intake air is diverted through a perforated air delivery tube disposed adjacent to the grate to provide combustion air for the combustible material.

Abstract: An assembly of coaxial rotor units which form part of a grate in an industrial furnace and serve to transport as well as to admit air to solid fuel in uncombusted and/or at least partially combusted state. Each rotor unit has a shell which is assembled of heat-resistant fuel-contacting rings and has gaps for discharge of air into fuel, a hollow core which is received in and rotates with the shell and whose cylindrical wall has apertures for admission of air into compartments disposed between the shell and the core and communicating with the gaps between the rings. The end walls of the core rotate with or relative to trunnions at least one of which admits air into the core so that such air flows through the apertures of the cylindrical wall, into the compartments and issues via gaps to contact the fuel.

Abstract: A plurality of interconnected pipes are installed in a fireplace to utilize the heat generated therein for the purpose of heating a room. The pipes are arranged in upper and lower sections that provides a pair of closed paths in which air is circulated by a fan. Cast iron slugs are spaced within the pipes in order to transfer heat to the circulating air and to increase the air turbulence. Outlet conduits receive heated air from the upper and lower sections and distribute it in the area that is to be heated.

Abstract: A heat exchanger adapted to be readily assembled and installed in an existing fireplace to recover heat which would otherwise be lost up the fireplace chimney is comprised of a plurality of upright U-shaped tubes secured together in laterally spaced relation by a rear plate removably attached across the rear, upright segments of the tubes. The heat exchanger is placed in an existing fireplace with the open front ends of the bottom and top tubular segments facing towards the front of the fireplace, and with the bottom tubular segments resting on the fireplace floor under a separate, fire grate. A manifold connected to a forced air blower may be removably connected to the forwardly facing, open front end of the bottom tubular segments of the heat exchanger to permit either forced or convection flow of air from a room through the heat exchanger tubes for heating, the heated air being expelled back into the room through the open front ends of the top tubular segments of the heat exchanger.