Abstract: This invention is an attachment for installation along a flue duct between a heater and a chimney, including a flue duct section, having a jet tube therein, receiving air from an exterior motor-driven fan, so as to create a vortex and a third stage burner at the jet tube end.

Abstract: An induced draft stove has a housing in which a food-supporting grate is disposed above a solid fuel-supporting grate. Burning solid fuel within the stove creates an induced flow of ambient combustion air to the fuel which is sequentially drawn into a pair of manually dampered inlet plenum boxes carried by the housing, through an air supply manifold, and into the open ends of a laterally spaced series of horizontally extending air delivery tubes which are removably positioned within the housing beneath the fuel grate. Combustion air entering the tubes is drawn downwardly through bottom outlet openings therein, flowed upwardly along lower exterior surface portions of the tubes, through the spaces between adjacent tube pairs, and then upwardly to the burning fuel. Upper side portions of the tubes shield the bottom outlet openings therein to prevent ash and other fuel bits falling from the fuel grate from clogging these outlet openings.

Abstract: A wood stove is described having a firebox with a baffle mounted therein that extends forward from a rear wall terminating in a forward edge spaced from a front wall. The wood stove has a front opening with a door thereon that includes a window enabling visual observation of the fire in the fuel combustion chamber. Air is emitted into the front wall and is directed downward in a thin laminar flow over the glass to wash the glass and to create a flow of air and gases downward along the front wall, rearward along the bottom wall, upward along the back wall and forward along the baffle in somewhat of a circular flow. The firebox is mounted on a pedestal with a primary air supply means drawing air through the hollow pedestal to an intake within the hollow pedestal for directing air through a channel to the back wall. The back wall includes a diffuser plate for directing air into the fuel combustion chamber to wash the fuel from the rear to assist in primary combustion.

Abstract: The efficiency of a wood burning stove is enhanced in a number of different ways. The first is a means to first preheat air in the lower part of the airspace in the jacket before the air passes through heat exchange tubes in the firebox. The second is to discharge the hot air in the upper part of the jacketed airspace along with the hot air from the heat exchange tubes into the enclosure to be heated. The third is to deflect the discharged hot air downward to decrease the temperature differential from floor to ceiling in the enclosure being heated. The fourth is to deflect the fire and hot gasses from the firebox away from the flue so that they must pass parallel in heat exchange relationship with the top of the stove before they can enter the flue. A fifth is to provide a second grate below the heat exchanger tubes, which act as a first grate, to catch burning embers which fall between the tubes of the first grate and provide complete combustion of the embers.

Abstract: A biomass stove has an outer chamber formed by a continuous side wall which is connected to a bottom wall. An air inlet is formed in the bottom wall for allowing introduction of air into the interior of the outer chamber. A fuel basket, also formed as a continuous side wall attached to a bottom wall, is located within the outer chamber. In the fuel basket, near the bottom of the fuel basket, a grate is positioned. First and second reflecting members are positioned below the grate within the fuel basket. Air inlets are located along the bottom periphery of the fuel basket with primary air flowing up through the air inlets and over the reflecting members and through the grate into a fuel supply which can be located within the fuel basket on the grate. One or more of the primary stoves can be suspended in a support housing to form an appropriate multi-burner stove.

Abstract: An outdoor wood-fired furnace which heats water for domestic use and provides heat is disclosed. The furnace has a water jacket, sides, top and ends. A main distribution chamber is provided for air on its bottom with outlet means to the firebox. The water jacket includes a large containment area in the top and an L-shaped baffle, having a horizontal leg and a vertical leg. Behind and above this L-shaped baffle is a similarly shaped air space which provides a passage between the baffle and the liquid cooled rear wall and the container for hot gases from the firebox to enter a flue. Means is provided to emit air from the main distribution chamber side through pipes to the fire.

Abstract: A solid fuel burning stove having a catalytic converter apparatus located above the stove combustion site. The apparatus includes a horizontal partition having a first opening in direct communication with the stove flue and a second opening adjacent catalytic elements. A by-pass damper is slideable on the partition to open and close the first opening. The by-pass damper is connected via a hollow rod to a handle located at the front of the stove. Exit ports are located in the hollow rod to provide supplemental heated air to the catalytic elements.

Abstract: An intake air pathway for a wood-burning stove is provided with a control mechanism which automatically responds both to changes in temperatures for controlling the amount of intake air flowing in the pathway and to pressure due to back puff conditions in the stove for closing the intake pathway with and thereby preventing emissions due to back puff. The point of control of the intake pathway may be placed along different points of the pathway. Control valve and check valve functions may be accomplished with a single control surface (i.e., plate or flap), or alternatively, be segregated into two control surfaces. The control arrangement is disposed such that gravity always acts as a safety feature to close the intake air pathway during an uncontrolled fire (e.g. chimney fire) or physical failure of the control apparatus. A fixed-shield baffle system surrounding a combustor of the stove causes reversals of combustion gasses and a secondary air flow supplied to the combustor.

Abstract: A catalytic combustor assembly includes a housing containing a catalytic combustor for insertion into the firebox of an existing stove. The housing engages and hermetically seals against the ceiling of the firebox surrounding the flue outlet of the stove to define an airtight passageway for volatile gases from the firebox to the flue outlet. The housing further defines a pair of secondary combustion air inlets and connected conduit for heating and then directing secondary air into the defined passageway to mix with the volatile gases upstream of the catalytic combustor. A bypass door is also mounted within the housing for selectively allowing the volatile gases to bypass the combustor in passing from the firebox to the flue outlet.

Abstract: Stove for burning solid fuels, particularly wood. The stove has a pedestal which has a primary air inlet and an ash drawer; an upright rectangular main housing which is divided internally into a fire box section and a section for combustion products; a housing for electrical components on the back of the main housing; and a flue. The partition between the fire box and the top portion has a first passageway with a catalyst therein and a damper-controlled bypass passageway. Primary air is admitted beneath the grate and passes upwardly therethrough. Secondary air is admitted to the fire box near the glass-panelled charging doors for solid fuel. The stove has a catalyst chamber for completing combustion of the incompletely burned gases in the fire box.

Abstract: A wood burning device comprising a metal box with a flue, an automatic flue damper, a combustion chamber formed by layers of insulating refractory material, a transparent ceramic glass front, an insulated refractory baffle forming the top portion of the combustion chamber, a means for introducing air into the combustion chamber, and a smoke deflector upstream from the flue. The stove further includes a support for tilting the box backwards, and a latching mechanism for a slideable door on the ceramic glass front.

Abstract: A high-efficiency clean burning heater for the burning of wood or coal is disclosed. The heater has a primary combustion chamber for the burning of solid fuel positioned above a secondary combustion chamber for the burning of combustible gases and pollutants which pass downwardly from the primary combustion chamber. Separate air supplies are provided for the two combustion chambers and the supply of air to the primary combustion chamber is governed by a damper plate to control the burn rate.

Abstract: A pollutant removal/heat exchange apparatus is mounted to a wood burning stove to receive the emission products from the stove. The apparatus comprises a plurality of vertically aligned tubular electrodes which define vertical through passageways. Negatively charged disc-like electrodes are positioned within the tubular electrodes. Partially burned hydrocarbons and moisture in the emission products become negatively charged as they pass through the tubular electrodes to become deposited on the inner surfaces of the tubular electrodes. Ambient air is directed through the passageways between the tubular electrodes to extract heat from the emission products, with the heated air being discharged from the apparatus. The electrostatic precipitation of the material on the tubular electrodes not only removes undesired material from the emission products, but also enhances heat exchange with the ambient air passing through the apparatus.

Abstract: An improvement in a woodburning stove of the type including an exhaust flue opening; a combustion chamber for primary combustion, having an access door, a support for wood to be burned and a primary air inlet means for supplying primary air to support primary combustion of the wood to produce flue gases containing combustible particulate material; conduit means for directing the flue gases from the combustion chamber to the flue opening in a preselected path; and, secondary combustion means for burning the particulate material in the flue gases before the flue gases pass through the exhaust flue opening.

Abstract: A heating system designed to extract more than the usual amount of heat from a given amount of fuel by controlling the route of smoke from a firebox through a smoke duct over a tortuous path and exposing the walls of the smoke duct to ambient air, thereby increasing the efficiency of the heating system.

Abstract: Wood burning stove having several features for reducing emissions output and for improving energy efficiency by increasing the supply of oxygen to combustible materials, by increasing the mixing of oxygen with combustible materials, and by lengthening the residence time of combustible materials within the stove. The features include a turbulence-creating means positioned at an upper, front region of the combustion chamber, and a baffle located near the outlet for increasing both turbulence and the pathway of combustible materials exiting the stove.

Abstract: A stove comprises walls defining a main air inlet, a flue outlet and four chambers through which gas passes sequentially from the main air inlet to the flue outlet during normal operation of the stove. The chambers comprise a pre-heat plenum chamber into which the main air inlet opens, a main combustion chamber for containing solid fuel to be burned and into which gas passes from the pre-heat plenum chamber, a second combustion chamber which is downstream of the main combustion chamber with respect to the flow of gas from the main air inlet to the flue outlet, and a third combustion chamber from which the combustion gas outlet opens.

Abstract: A solid fuel furnace having an oscillating grate plate solid fuel burner therein wherein the grate plates are in a stepped arrangement and every other plate moves together, in an opposite direction from the adjacent plates so that the solid fuel is kept moving down the step grate positively. Additionally, the solid fuel burner is mounted in a furnace housing which is designed to utilize the hot combustion gases to preheat incoming or makeup air for a blower used for supply air flow for heating. Baffles are used to provide a substantially elongated path for the combustion gases to ensure adequate heat exchange in a compact space.

Abstract: A stove to burn solid fuels, said stove comprising a combustion chamber with a front (13) with a fuel charging aperture (14) therein and a door (3) with a transparent viewing panel (33) therein mounted over the aperture (14), a baffle (15) dividing the interior of the combustion chamber into a primary combustion zone (A) and a secondary combustion zone (B), a closeable port (16) in the baffle (15) connecting the primary and secondary combustion zones, a combustion gas discharge port (17) to atmosphere from the secondary combustion zone, a gas screen (24) in the gas path between the primary and secondary combustion zones, the gas screen being constructed from materials that will glow at a temperature below the ignition temperature of combustion gases, primary and secondary combustion air inlets (22 and 30) discharging into the combustion zone adjacent a top edge of the door panel (33) and the gas screen (24) respectively, manually resettable temperature actuated flow control means (34) regulating the amount of

Abstract: A combustion chamber for heating systems operated with liquid fuel can be used as vehicle heaters but also as heating systems for e.g. cooking purposes and whose control range is expanded as compared with known devices. The combustion chamber includes two sections separated from the combustion space by a plate with a passage opening. Depending on the purpose of use, a different flame guiding insert is arranged between the combustion space and the combustion chamber.

Abstract: Solid fuel heating appliance having high thermal efficiency and low levels of polluting emissions. The heating appliance includes an insulated secondary combustion chamber where a mixture of exhaust gases from the primary combustion chamber and secondary air is burned. A catalytic igniter is provided in the secondary combustion chamber to lower the ignition temperature of the unburned volatile gases from the primary combustion chamber. Regenerative feedback structure is provided in heat exchange relationship with the exhaust from the secondary combustion chamber to preheat the mixture entering the secondary combustion chamber, catalytic igniter, and the regenerative heat transfer assure substantially continuous combustion within the secondary combustion chamber even when conditions in the primary combustion chamber change.

Abstract: A firebox for a wood stove provides primary, secondary, and tertiary supplies of combustion air to the firebox. The primary supply of air enters from the front of the firebox and establishes a combustion flow downwardly to the fire. Smoke containing particulates and gases then rises from the fire to a flue opening through the top of the firebox. The secondary supply of air is added to the flow of smoke as it rises to combust particulates and gases in the smoke. The tertiary supply of air is then added to the flow of smoke in surrounding relationship to the smoke flow as it passes through a restriction opening, further combusting the smoke. The primary, secondary, and tertiary supplies of air enter the firebox through primary, secondary, and tertiary inlet ports, the cross-sectional areas of the ports being in the ratio of 2 to 1 to 1 to regulate the flow of air inward. The secondary and tertiary air supplies are preheated before being added to the combustion flow.

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: A solid fuel heating apparatus has combustion air supplied in a controlled manner by a manifold. The manifold has a first branch that directs combustion air to the interior of the fuel ignited within the firebox and a second branch that extends along the forward edge of a baffle that extends from the rear wall of the firebox across a flue. Air issuing from the second branch is directed towards the fuel within the firebox so that a bodily rotation of gases within the firebox is obtained. A third branch extending generally parallel to the second branch is also provided and directs air towards the first branch. The air delivered by the second and third branch is roughly twice that delivered by the first branch and it has been found that this provides complete combustion of the fuel within the stove.

Abstract: A forced draft, solid fuel burning stove incorporates a plurality of air distribution conduits disposed intermediate an ash collection receptacle and a solid fuel support grate. The forced draft air is directed upwardly onto a deflector in a manner to permit the flow of air to be evenly distributed across the solid fuel and across the food support surface. The movement of the forced draft air against the deflector establishes a turbulent, randon movement which prevents high concentrations of forced air directly upon the solid fuel, which would otherwise loosen ash particles from the solid fuel and carry them upwardly onto the food support surface.

Abstract: A low emission stove includes a firebox divided by an inverted baffle into a large lower primary combustion chamber, in which the solid fuel is placed, and a substantially smaller upper secondary combustion chamber. A restrictive vertical passage formed between a sidewall of the firebox and a downturned free end portion of the baffle connects the two chambers to convey combustion products produced in the lower chamber to the upper chamber before exiting from the stove. The air for the primary combustion in the lower chamber is drawn from beneath the firebox and directed upward to the firebox. The air enters the primary chamber through air inlets on multiple sides of the primary chamber, both at the fuel level and substantially above the fuel level. The combustion products produced are temporarily trapped within the primary chamber by the downturned free end portion of the baffles.

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: Exterior retrofit system for attachment to wood or coal-burning stoves including a secondary combustion chamber and a catalytic igniter. The secondary combustion chamber is lined with refractory material and is arranged to preheat flue gases emanating from the woodburning apparatus before ignition at the catalytic igniter. The refractory walls have an undulating structure to increase mixing and residence times for more complete burning. Provisions are made for introducing additional combustion air into the secondary combustion chamber. Combustion performance is improved resulting in reduction of cresote deposits and particulate emissions and reduction in the amount of fuel consumed for a given heat output. The retrofit unit is self-contained and requires no permanent or complicated modification to the stove. This system also has application for use on the interior of a stove, both as a retrofit and as the basis for a specifically designed stove.

Abstract: A wood or coal burning heater or stove employing a catalytic combustor in its combustion chamber having a primary air supply which feeds air to the fuel, and a secondary air supply which feeds air directly to the catalytic combustor by means of an air diffuser which sprays air evenly over the undersurface of the catalytic combustor. Combustion gases from the burning fuel in the combustion chamber pass through the catalytic combustor to a heat exchanger and then to an exhaust flue. The primary and secondary air supplies are simultaneously controlled so that maximum primary air and reduced secondary air are supplied when maximum heat is demanded, and reduced primary air and maximum secondary air are supplied when minimum heat is demanded. The ratio of primary to secondary air is precisely controlled to maximize overall heating efficiency consonant with high BTU output.

Abstract: A catalytic stove comprised of a housing having a fuel burning chamber and an effluent chamber separated by a domed common wall. An air inlet port is located in the fuel burning chamber and draft air is introduced to burning fuel through an apertured thermal control unit which detects changes in stove temperature. A closure flap is rotatable across the aperture. 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. Effluent from the fuel flows substantially directly and smoothly from the fuel to a finned holder at the top of the domed wall. The fins then create turbulence in the combustible gases emanating from the burning fuel.

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: A heater is disclosed for burning combustible particulate fuels. The fuels are delivered to an internal retort at a constant rate. They are burned at an open end of the retort with the aid of a primary air supply manifold that surrounds the open end of the retort and directs primary combustion air into the particulates at the open retort end. Secondary combustion air is directed through an annular air supply manifold situated above the open retort end. The hot exhaust gases pass upwardly through a combustion chamber and subsequently downwardly through an exhaust gas plenum to an exhaust gas discharge. Flow of the combustion air and exhaust gases is induced by a vacuum blower mechanism by which a reduced pressure is produced within the combustion chamber to draw air through the primary and secondary air supply manifolds. The exhaust gases drawn off by the vacuum mechanism are pressurized on a discharge side of the vacuum mechanism.

Abstract: A woodburning stove, fireplace, or the like which includes a hearth in a chamber with a flue outlet at a top thereof and a closeable bottom plate provided in a bottom of the chamber. A further chamber is provided under the plate, with the further chamber being lined with a refractory material. The further chamber includes a flue outlet duct to the upper chamber communicating at a rear end thereof so that flue from the fuel fired in the further chamber is substantially entirely combusted, with the combustion temperature being high and the combustion time for a given fuel supply in the further chamber being considerably longer as compared to the same amount of fuel in, for example, a conventional heating stove.

Abstract: A stove for burning wood, coal and other fuels comprised of flammable solids that among other things produce one or more flammable gases when heating or burning. The preferred form of the stove has three modes of operation--a rapid burning mode, a normal or medium burning mode and a banked mode. The user makes a preliminary decision as to whether the stove is to be operated in its normal mode or banked mode. Thereafter, controlled by temperature responsive means, the stove moves itself fully automatically back and forth from the rapid burning mode to whichever one of the other two modes of operation has been preselected by the user.

Abstract: Apparatus supporting a catalytic converter for a burner comprising a support including an opening for passage of exhaust gases therethrough, a catalytic converter mounted on the support for movement into and out of an operating position adjacent to the opening to receive the exhaust gases, and means extending from the support for causing the catalytic converter to be moved into and out of the operating position.

Abstract: Free-standing stove/fireplace apparatus includes a plurality of heated air chambers disposed about a firebox and flue, with air intake and air outlet passages located at various heights for the convection heating of air in the room in which the apparatus is disposed and with provisions for utilizing outside air for combustion purposes to allow the firebox to be isolated from the room air.

Abstract: Apparatus for supporting a catalytic converter for a burner including a housing having an opening for directing the exhaust gases to a catalyst region and a by-pass opening permitting the exhaust gases to by-pass the catalyst region, a baffle positioned over the catalyst region and having a groove formed in it and a tab extending from one end and adjacent to the groove, a closure movably mounted to open and close the by-pass opening, and a control rod slidably and pivotally mounted within the groove and having one end connected to the closure to open and close the by-pass opening by pivoting of the rod, the rod being lockably engageable by the tab by longitudinal displacement of the rod when in a pivotal position corresponding to closing of the by-pass opening, and having handle means extending from the other end for permitting pivoting and longitudinal displacement of the rod.

Abstract: A stove and method for burning solid fuels having an insulated primary combustion chamber, uniform distribution of preheated primary air through upward facing holes in a grate, downward flow of combustion gas through the grate, retention of hot coals in the grate structure, preheated secondary air, individually controlled primary and secondary air flows, insulated vortex combustion chambers for secondary combustion, longitudinally finned tubes as a first stage heat exchanger, plate-fin assembly as a second stage heat exchanger, an induced draft fan to draw the air and combustion gases through the combustion chambers as well as the heat exchangers, and a forced air fan to blow cool room air through the two stage heat exchanger.

Abstract: A combustion device for solid fuel of low ash content, which has a holding board for holding the solid fuel of low ash content which has no grooves or slits, a cylindrical body forming a combustion chamber mounted on the holding board and/or a holding cone, an air absorbing space being formed between the lower edge of the cylindrical body and the holding board, and the ignition being effected by an ignition means.

Abstract: A mechanical thermostat for modulating the temperature of a solid fuel-burning stove, including a casing, a thermostat coil mounted in the casing to sense the stove wall plate temperature; a downwardly-spaced air admission mechanism. The air admission mechanism includes a pair of identical openable and closable orifices by way of a variable closure mechanism. A linkage connects the latter with the coil. The relation between temperature fluctuation and the effective open area of the orifices is expressed by a mathematical equation allowing for very constant desired stove temperature during burning time. A firing control for the stove is further provided.

Abstract: A solid fuel combustion chamber having fire bars supporting the fuel and two screening walls located above the fire bars, one screening wall overlying the other having an inlet opening larger that and communicating with the outlet of the underlying screening wall.

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: Woodburning heating apparatus including a catalytic igniter for increasing heating efficiency and reducing polluting emissions. The apparatus includes a secondary combustion chamber in gaseous communication with a primary combusiton chamber. The secondary combustion chamber is lined with a refractory material and includes a perforate catalytic igniter through which combustion gases from the primary combustion chamber flow. The secondary combustion chamber further includes refractory baffles arranged to enhance mixing of the combustion gases and located to re-radiate heat onto the catalytic igniter. Preheated secondary combustion air enters the secondary combustion chamber so that the combustion gases are more completely burned to improve heating efficiency and reduce emissions.

Abstract: The invention relates to a combustion method and apparatus for carrying out this method.The method comprises establishing (a) a combustion zone of hot embers above and near a grate and (b) a column of particulate fuel above and resting on said hot embers, supplying combustion air to said combustion zone only, flowing products of combustion generated at the interface between said hot embers and particulate fuel and in said hot embers downwardly through said grate, then upwardly in heat exchange relation to air in a space to be heated, and finally to exhaust.The apparatus comprises means for holding a column of particulate fuel above a grate, means for flowing air into a combustion zone above and adjacent to said grate at the bottom of said column only, and means for flowing products of combustion downwardly through said grate then upwardly through a heat exchange zone to exhaust.

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: An apparatus for placement in the effluent path of the combustible gases created by fuel burning in a combustion chamber and delivering such combustible gases to a catalyst is disclosed. A finned holder for placement downstream of the burning fuel is provided. The fins on the holder serve to create turbulence in the combustible gases emanating from the burning fuel. The holder also serves to support a secondary air introduction ring. The ring uniformly introduces preheated secondary air to the combustible gases through a plurality of ports in the ring thus forming a substantially homogeneous mixture of gases. The homogeneous mixture of gases is delivered to a catalyst located above and downstream of both the holder and ring.

Abstract: The present invention is a vertically loaded wood-burning stove in which the wood stands on end and burns only on the lower end, sliding down into the combustion zone as it is consumed. The wood-burning chamber is air tight with the exception of unobstructed air inlets at the bottom of the chamber. The hot combustion gases pass from the combustion chamber through unobstructed air passageways to a second combustion chamber which is vertically arranged and spaced from the first combustion chamber to form an unobstructed secondary air inlet which provides pre-heated air to the second combustion chamber.

Abstract: This stove is divided by a partition into a lower, combustion chamber, and an upper chamber which communicates directly with an exhaust opening in the stove. A catalytic converter is removably mounted in an opening in the partition. A by-pass damper, which is connected to the stove door, is normally held closed over a by-pass opening in the wall of the lower chamber, when the door to the stove is closed, whereby all combustion gases from the lower chamber must pass upwardly through the converter and the secondary chamber to the exhaust opening. When the stove door is opened, the by-pass damper tilts by gravity into an open position so that combustion gases from the lower chamber pass directly to the exhaust opening rather through the upper chamber, and rather than being accidentally discharged out of the open door. The converter causes all by-products of combustion to be subjected to a secondary combustion in the converter before passing to the exhaust opening.

Abstract: A heating apparatus for operating in one or the other of two combustion modes has a frame assembly enclosing a primary and secondary combustion chamber. A baffle, separating the chambers, provides for gaseous communication therebetween. Preheated primary and secondary combustion air is directed in a controlled fashion to the front of the frame assembly across a viewing window to keep the window clear. The apparatus further has an off center damper movement system, means for defining a secondary air flow path through the primary combustion chamber, and a structure which can be changed for operation either as a wood burning or a coal burning stove.

Abstract: A firebox for a stove is defined by top, bottom, side and end walls and employs a loading door in one of the end walls. A main draft opening associated with an adjustable damper control is provided adjacent the lower portion of the firebox and an auxiliary draft opening associated with an adjustable damper control is provided adjacent the top portion of the firebox. In a preferred arrangement the main and auxiliary draft openings are disposed adjacent one of the end walls. Also, in a preferred arrangement, the auxiliary draft opening is disposed upwardly within at least the upper one-third of the firebox. The particular structure of the stove facilitates good combustion for heating but at the same time provides an efficient shut-down condition that will maintain a small holding fire without causing creosote to build up in the flue. The main draft opening is associated with a movable door arranged to be forced open in the event of pressure being developed in the firebox.