Abstract: A stove includes a combustion chamber, a fuel grate positioned within the combustion chamber, and a pellet adapter removably positionable on the fuel grate. The fuel grate includes a number of first ventilation holes. The pellet adapter includes a number of second ventilation holes sized and shaped to prevent passage of a fuel pellet. The pellet adapter also includes a raised outer rim and a central protuberance with a height greater than the height of the raised outer rim.

Abstract: An appliance includes a burn pot assembly and air distribution ducts that distribute air into a burn chamber of the burn pot assembly, and distribute heated air to a cooking chamber of the appliance. A first air supply system may distribute air into the burn chamber, and a second air supply system may distribute heated air through one or more outlet manifolds towards the cooking chamber.

Abstract: Provided herein is a system and method for heat exchange of a vehicle. The system comprises an enclosure disposed on the vehicle. The enclosure comprises a fan disposed at a base of the enclosure, one or more sensors within the enclosure, and a cover on an exterior of the enclosure. The cover comprises a hole pattern to selectively permit an airflow to enter the enclosure. A deflector is disposed on the vehicle outside the enclosure and configured to direct an airflow through the hole pattern.

Abstract: A pellet stove includes a hopper for storing pellets, a basket for receiving the pellets by gravity, a duct for conveying combustion air to the basket, and a conduit for conducting heated air away from the basket. The position of the basket is adjustable, such as by raising and lowering it, or by rotating it, so as to control the number of pellets in the area of most intense combustion. One or more optional burn plates, positioned below the basket, provide platforms on which pellets falling through the basket can burn down to a smaller size. The pellet stove requires no external source of power. The stove so constructed enables quiet, efficient and clean burning of the pellets.

Abstract: The present disclosure provides a liquid injection device, including a conveying mechanism, a weighing mechanism, a lifting mechanism and a guide mechanism. The weighing mechanism is positioned below the conveying mechanism. The lifting mechanism is configured to transfer a battery on the conveying mechanism to the weighing mechanism. The guide mechanism includes a first guide plate, a second guide plate and a power member. A distance between the second guide plate and the first guide plate may be adjusted through the power member, so that the liquid injection device may be compatible with batteries with different models. It is unnecessary to perform model change operation when the battery is changed, thus improving production efficiency.

Abstract: A hybrid wood-burning fireplace assembly configured for burning wood-based fuel, wherein the burning generates combustion exhaust. The assembly comprising a fire box having an interior area, a baffle in the interior area defining lower and upper combustion chambers relative to the baffle. The upper combustion chamber has an upper exhaust passageway between baffle and the top portion of the firebox. A secondary combustion airway has air outlets in the firebox that direct the secondary combustion air adjacent to the baffle to mix with the exhaust for non-catalytic secondary combustion of the exhaust before the exhaust flows through the upper exhaust passageway. A catalytic combustion unit is positioned above the baffle and across the upper exhaust passageway, whereby the exhaust will pass through the catalytic combustion unit after the non-catalytic secondary combustion of the exhaust and before the exhaust exits the upper combustion chamber through the upper exhaust passageway.

Abstract: There is provided a wood pellet burner assembly for a wood pellet boiler, not shown. There is a fixed and easily removable fuel apertured grate mounted above and spaced apart from a base wall forming part of a main support enclosure. A movable scraper subassembly carrying an apertured flame tube is provided which can be moved in and out of the main support enclosure to perform a scraping action on the fixed fuel apertured grate to deliver ash and clinker which have not fallen through the grate during combustion off the grate out of the main support enclosure. This cleaning operation can be carried out at suitable preset time intervals.

Abstract: A combustion chamber, having an upper part and a lower part, may include an annular constriction, in combination with the combustion chamber, to aid in directing partially combusted gases such as carbon monoxide away from the periphery of the combustion chamber back toward its center, and into the flame front. The annular constriction may also impede the flow of partially combusted gases located at the periphery, thus increasing the time these gases spend within the combustion chamber and increasing the likelihood that any products of incomplete combustion will undergo combustion. The combustion chamber may further comprise a dual burner cooktop for directing combustion gases and exhaust to multiple cooking vessels. In further embodiments, the combustion chamber may be made of, lined, or clad with a metal alloy comprising iron, chromium, and aluminum.

Abstract: This invention describes a stove comprising a combustion chamber and a flue for removing exhaust from said combustion chamber, where said combustion chamber and said flue are connected via a passageway; said combustion chamber comprising a top and a bottom, where said top and said bottom are connected by one or more sides; a catalytic unit arranged between said combustion chamber and said flue in said passageway; said catalytic unit provides a guide way for the exhaust, where said catalytic unit comprises at least one isolating members and at least one catalytic member, said catalytic member comprising a first wave-like structure, said first wave-like structure being provided on at least one catalytic surface of said catalytic member and, in use, at least partly being in contact with the exhaust and, where, in use, the direction of the exhaust is substantially transverse to the waves of said first wave-like structure.

Abstract: One or more techniques and/or systems are disclosed for a portable gas-fired heater comprising a ousing, a burner assembly, and a carbon dioxide detector system. The housing may, at least, partially enclose one or more fuel sources. The burner assembly can be enclosed by, and recessed into, the housing.

Abstract: A mobile heating device operated with liquid fuel is provided, having: a combustion chamber (2) comprising a combustion air inlet (3), wherein the combustion chamber adjacent to the combustion air inlet (3) comprises a widening portion (20) the cross-section of which widens with increasing distance from the combustion air inlet (3) and in which in operation combustion air and fuel are converted in a flaming combustion; a fuel supply which is arranged such that fuel is supplied into the widening portion (20); and an air guide device (6) being adapted to feed combustion air into the widening portion (20) with a flow component directed in the circumferential direction such that an axial recirculation region (RB) forms in the widening portion (20) in which gases flow in the direction towards the combustion air inlet (3) oppositely to a main flow direction (H). The combustion chamber (2) is fluidically sectioned into a primary combustion zone (PZ) and a secondary combustion zone (SZ).

Abstract: A mobile heating device operated with liquid fuel is provided, having: a combustion chamber (2) comprising a combustion air inlet (3), wherein the combustion chamber (2) adjacent to the combustion air inlet (3) comprises a widening portion (20) the cross-section of which widens with increasing distance from the combustion air inlet (3) and in which in operation combustion air and fuel are converted in a flaming combustion; a fuel supply which is arranged such that fuel is supplied into the widening portion (20); and an air guide device (6) being adapted to feed combustion air into the widening portion (20) with a flow component directed in the circumferential direction such that an axial recirculation region forms in the widening portion (20) in which gases flow in the direction towards the combustion air inlet (3) oppositely to a main flow direction (H).

Abstract: An air flow modulating device comprising a flapper, a mount and a conduit. The conduit may be T-shaped and may be attached to an intake conduit of a sealed combustion condensing appliance, or other appliance having an air intake conduit, through a first portion of T-shaped conduit. The mount may be connected to a second portion of T-shaped conduit and the flapper may rotate between an open position and a closed position about an axle of the mount. The device operates to allow for a sealed combustion condensing appliance to immediately intake interior air when an exterior air source is obstructed, limited or reduced, or in response to changes in air pressure due to uncontrollable natural forces.

Abstract: The present disclosure provides woodstoves that, optionally, produce low emissions. In certain embodiments, the woodstove includes a housing, a firebox disposed in the housing, an air regulator and a secondary air pipe. The air regulator includes a primary air aperture configured to supply primary air to a fire located in the firebox, a plurality of secondary air apertures configured to supply secondary air to a combustible gas emitted by the fire, and a secondary air damper. The present disclosure also provides methods of operating such a woodstove. As measured according to Method 28 of the U.S. Environmental Protection Agency, the weighted average emission rate of the woodstove of certain embodiments of the invention is no greater than about 4.5 grams of particulate emissions per hour.

Abstract: A method for burning a fuel in a wood stove having a door to a combustion chamber with a base, which combustion chamber is isolated from the air by an exhaust and an intake at which intake there is provided an air regulator having at least primary, secondary and tertiary air intake ducts. The stove is controlled by a burn controller configured to operate between the different operating, i.e. different combustion states.

Abstract: A solid fuel heating apparatus (1) comprising a combustion chamber provided with a glass door (4) opening to the outside, an intake device (11) for the intake of outside combustion air into said chamber, an outlet duct for the burnt gases (2) and a sealed preheating enclosure for preheating the combustion air, conveying said air to the combustion chamber, connected at a first end to the intake device (11) and ending at a second end with a plurality of openings (9) releasing the air preheated by the preheating enclosure into the combustion chamber, characterised in that the preheating enclosure consists of a set of sealed heat exchanging pipes containing the combustion gases and the burnt gases (3, 8, 12, 15, 17, 18, 19), ending with the abovementioned openings (9), which are variable in size and are arranged in such a way as to modulate the flow of preheated air released into the chamber, enclosing the flame and combustion area in the natural conical shape of said chamber.

Abstract: An oven has an enclosed heat exchange zone for use with biomass fuel. The oven has a body which is able to be placed on the ground. The body has a combustion cabinet and an auxiliary equipment cabinet. The combustion cabinet has a burner received therein. The burner has a fire grate, a side plate, a blowing space, and a hearth. A heat exchange zone is defined by the surrounding tubular inner wall; a side heating zone being defined by a tubular inner and a tubular outer walls. A chimney is formed on the tubular outer wall in communication with an upper portion of the side heating zone. An opening is defined in the top of the combustion cabinet right above the tubular inner wall.

Abstract: The present invention pertains to a combustion device which is mounted to a wood boiler or the likes and generates high thermal power while decreasing soot by means of a simple structure.

Abstract: Disclosed herein are devices and methods that aid in providing high efficiency stoves for developing and underdeveloped regions. In some embodiments, the stoves are plancha-style stoves comprise cast iron planchas that are more durable and efficient that existing stoves. The plancha-style stoves, described herein may comprise a combustion chamber comprising an inlet, a stack chamber comprising an inlet and an outlet; a gas path chamber, comprising a ceiling and a floor, wherein the ceiling is defined by a removable plancha cooking surface having a substantially planar upper surface and a lower surface; a chimney box; and a chimney. In many embodiments, the stack chamber defines a cross-sectional area that is larger than the cross-sectional area of the inlet to the combustion chamber to prevent smoke from escaping the combustion chamber through the inlet.

Abstract: A hybrid wood-burning fireplace assembly configured for burning wood-based fuel, wherein the burning generates combustion exhaust. The assembly comprising a fire box having an interior area, a baffle in the interior area defining lower and upper combustion chambers relative to the baffle. The upper combustion chamber has an upper exhaust passageway between baffle and the top portion of the firebox. A secondary combustion airway has air outlets in the firebox that direct the secondary combustion air adjacent to the baffle to mix with the exhaust for non-catalytic secondary combustion of the exhaust before the exhaust flows through the upper exhaust passageway. A catalytic combustion unit is positioned above the baffle and across the upper exhaust passageway, whereby the exhaust will pass through the catalytic combustion unit after the non-catalytic secondary combustion of the exhaust and before the exhaust exits the upper combustion chamber through the upper exhaust passageway.

Abstract: Disclosed is a heating power adjusting apparatus of a hot blast heater which controls pressure of air supplied to a burner by executing selectively switching between the cross-sectional areas of orifices in a flow space of air located between a pump and a burner head, and thereby variably adjusts heating power generated from the burner. The heating power adjusting apparatus adjusts includes a valve body including an air injection part, an air exhaust part, and an air flow space between the air injection part and the air exhaust part, an orifice body rotatably installed in the air flow space of the valve body and provided with a plurality of orifices having different flow cross-sectional areas to variably adjust the flow rate of air, and a rotary knob to adjust rotation of the orifice body with respect to the valve body.

Abstract: The invention relates to a fume box having a separation partition (16) in the upper portion thereof that comprises a removable catalyst block (17) offset relative to the inlet (10) and the outlet (8), and an intake passage that can be blocked by at least one insulating block. Deflectors slow down the gases and fumes and protect the catalyst block against falling soot and particle. The invention is particularly intended for manufacturers of domestic combustion heating appliances, in particular those using wood.

Abstract: The present disclosure provides woodstoves that, optionally, produce low emissions. In certain embodiments, the woodstove includes a housing, a firebox disposed in the housing, an air regulator and a secondary air pipe. The air regulator includes a primary air aperture configured to supply primary air to a fire located in the firebox, a plurality of secondary air apertures configured to supply secondary air to a combustible gas emitted by the fire, and a secondary air damper. The present disclosure also provides methods of operating such a woodstove. As measured according to Method 28 of the U.S. Environmental Protection Agency, the weighted average emission rate of the woodstove of certain embodiments of the invention is no greater than about 4.5 grams of particulate emissions per hour.

Abstract: A vehicle heater (1) has a motor (4) and a combustion air fan designed as a side channel fan. The combustion air fan has a basic housing part (2), on which a drive shaft (3) of the motor (4) is mounted, and a fan wheel (10). The fan wheel (10) is connected to the drive shaft (3) of the motor (4). The motor (4) has a stationary coil support part (6) which is connected to a printed circuit board (7) and an armature (8). Furthermore, the combustion air fan has a gap tube (16) between the stationary coil support part (6) and the armature (8).

Abstract: A combustion apparatus for the burning of solid fuel using a plurality of secondary combustion zones is disclosed. The combustion apparatus includes primary and secondary air inlets, an inclined hearth and a unique second air source which washes up a window in the combustion apparatus creating a floating flame effect and rendering the window self-cleaning. A series of baffles define a secondary combustion pathway which optimizes secondary combustion of exhaust gasses and particulate matter. Coaxial rear and top direct venting apparatus are also disclosed. The combustion apparatus provided combusts a wide range of solid fuel at a high level of efficiency.

Abstract: A mechanical damper control can be used to regulate the temperature of a smoker, barbecue grill, or generally any stove chamber. The mechanical damper control includes a housing that can be coupled to an inlet or outlet of a stove chamber, either directly or using an adapter. A temperature responsive expandable member and a damper are coupled to each other, and to the housing. A damper adjustment can be manipulated to just close the damper at a point when the stove has reached a desired temperature. Further changes in the temperature of the stove chamber cause the expandable member to expand or contract, resulting in a corresponding opening or closing of the damper to maintain the stove chamber at a substantially constant temperature.

Abstract: A center burn technology for a stove or dryer for the burning of solid, loose or compressed fuels, or mixtures of fuels. The stove uses a center burn draft and combustion through the combustion material. The preferred embodiment of this stove consists of at least two bins, an outer exhaust bin and inner combustion bin. A vertically placed air core combustion tube is resting within a stabilizing support collar at the top and at the bottom the tube rests inside of a tapered apparatus. The smaller opening at the bottom of the tapered apparatus provides return gas venting and easy ash drop system to ash bin or pan below. Exhaust drafts through vents between said bins at the upper portion of the inner combustion bin. The stove provides a long efficient burn with a steady combustion temperature. The stove does not require the use of electricity.

Abstract: A venting system for a stove includes a screen disposed beneath a bottom opening of the stove and an elevation means for adjusting a height of the screen so as to enable the screen to selectively move close to or away from the bottom opening. More specifically, the elevation means includes a main body and an adjuster, and the screen includes an elevator. The main body has a fixation portion and a connecting portion. The fixation portion is fixed to a bottom of the stove, and the adjuster is movably connected to the connecting portion. The elevator and the adjuster are in a motional operative relationship. As such, the elevator can be elevated, by the adjuster to selectively move close to or away from the bottom opening.

Abstract: A cooking surface for a grill includes a cylindrical fire column. Food placed on the grill surface directly above the fire column will be impinged by the heat of the heat source, made even more intense by the upward, directional flow of air through the fire column. Food placed on the grill surface but not directly above the fire column can be cooked with indirect heat.

Abstract: A wood burning furnace providing, in sequential connection, an air box, a fire box with a wood storage box/primary combustion chamber and a secondary combustion chamber separated by an ash grate, a heat exchanger, an exhaust manifold, and a smoke stack. The air box has an input port attached to an intake air blower. The air box also has two dampers, a thermostatically controlled first damper providing controlled access to an updraft exhaust pipe connected to the smoke stack. The second damper provides controlled access to the wood storage box/primary combustion chamber.

Abstract: A heater including a heat dump opening and a heat dump cover moveable between an open and a closed position to selectively block flow of fluid through the heat dump opening. The heat dump opening is formed in the top of the housing, and the heat dump cover is biased toward the open position. The cover moves to an open position in response to a sensed preselected limit temperature to vent excessively heated air to ambient to prevent damage to the heater and a duct system and a building to which the heater may be connected. Air escaping the heater via the heat dump opening may cause replacement air to be drawn into the heater to cool the heater, including electrical components of the heater located near an inlet and an outlet of the heater.

Abstract: The present document describes a multistages combustion furnace system for thermal expansion of mineral particles which comprises: a furnace having an expansion chamber for receiving the mineral particles; a burner head to be connected at a distance for an atmospheric coupling of the furnace and for operating the multistages combustion furnace system; a furnace device to be connected at a distance for an atmospheric coupling of the burner head to offset the quenching effect of ambient air normally drawn in the furnace; and a tuyere for thermal expansion of mineral particles to be connected between the expansion chamber and the furnace device; wherein the multistage combustion furnace system is to be connected with an inlet of preheated air.

Abstract: A bio-mass fueled boiler operating at delivered efficiencies in excess of 90%. Pre-heated, pressurized primary combustion air is supplied to a primary burn chamber via horizontal and vertical orifice containing conduits. Exhaust gases are directed past a reflective secondary burner supplying pre-heated, pressurized secondary combustion air into a secondary burn/ash collection chamber. Exhaust gases are directed from the secondary burn chamber via exhaust conduits having axial and cross-sectional shapes and wall geometries that promote internal turbulence and heat transfer. One or more gas/oil fired burners are fitted to or between the primary and secondary combustion chambers. Several operating modes are provided via associated blowers, air baffles, liquid and gas fuel conduits, pumps and sundry stove sensors and servos coupled to microprocessor control circuitry.

Abstract: A vertical heat treatment apparatus including a furnace body having heater elements, and a treatment container, disposed in the furnace body, for housing and heat treating objects W to be treated. An air supply line and an air exhaust line are connected to the furnace body. An air supply blower and an air supply line valve mechanism are disposed in the air supply line, and an air exhaust blower and an air exhaust line valve mechanism are disposed in the air exhaust line. A protective tube is provided which penetrates through the furnace body and in which a temperature sensor signal line is housed, and a pressure detection hole is formed in the protective tube. A pressure detection sensor is connected to the pressure detection hole.

Abstract: Smoke escaping from an outdoor wood burning furnace may be effectively arrested with a smoke arresting unit. By mounting a smoke gathering manifold above the furnace door operatively connected to a vacuum source for drawing smoke discharging from the furnace chamber through an open furnace door, the gathered and arrested smoke may be discharged through a separate discharging chimney. The vacuum source may be activated when the furnace fan is switched off and the furnace door is opened for refueling.

Abstract: A method for operating a wood fired appliance, in one aspect, generally includes automatically moving a baffle to a lowered closed position from the raised open position in response to a top loading door being moved to a closed position to close the opening in a top wall. The baffle may also be automatically inhibited from being maintained in the raised opened position when the top loading door is disposed in the closed position. For example, a cam may be tripped or activated by lowering of the top loading door to cause the baffle to rotate about an axis and fall under the force of gravity to the lowered closed position, and the cam may inhibit the baffle from being raised when the top loading door is closed.

Abstract: A fireplace system having a fireplace cavity and a secondary combustion assembly disposed adjacent to a rear wall of the fireplace cavity. The secondary combustion assembly includes a plurality of combustion chambers configured to facilitate secondary combustion. A plurality of inlets are disposed in the rear wall of the fireplace cavity. One or more of the plurality of inlets are configured to provide fluid communication between the fireplace cavity and a respective one of the plurality of combustion chambers. An exhaust gas collection chamber is in fluid communication with at least the secondary combustion assembly. The exhaust gas collection chamber includes a vent configured to release exhaust gas into a chimney. An ambient air bypass aperture is disposed in a top baffle of the fireplace cavity. The ambient air bypass aperture is configured to divert at least a portion of ambient air entering the fireplace cavity into the exhaust gas collection chamber.

Abstract: The invention relates to a burner for solid fuel containing a space for a solid fuel to be burned, in which solid fuel space the flow of gas is arranged to be possible. The burner comprises at least one fire pipe (3,13) inside the solid fuel space, through the wall of which a possibility for gas flow is arranged.

Abstract: In a wood burning stove comprising a burning chamber (1) and a wood pellet burner (3), said wood pellet burner (3) is movable between a retracted position, in which the components of the wood pellet burner (3) are positioned outside the burning chamber (1), whereby the burning chamber (1) is suitable for burning wood logs etc., and an inserted position, in which the main components of the wood pellet burner (3) are positioned inside the burning chamber (1), and the wood pellet burner (3) can be activated to burn wood pellets (19) or similar particulate solid fuel inside the burning chamber (1).

Abstract: A heater being automatically fed with uniform geometry fuel units (2) whereby an improved combustion is obtained and it is adequate for domestic, commercial and industrial use; said heater comprises a supporting structure (16) and a combustion chamber (8) being supported by said supporting structure (16); the heater is characterized in that the combustion chamber (8) is exclusively fed on fuel by automatic feeding means; said automatic feeding means have an inlet region for receiving the fuel supplied by a user and an outlet region for automatically delivering the fuel to the combustion chamber (8).

Abstract: The air intake apparatus provides for additional auxiliary air to a wood or pellet burning stove. The apparatus is provided in more than one embodiment for fit to more than one type of stove. The curved T-handle controls the damper sleeve for dampened control of the auxiliary air.

Abstract: A pellet stove utilizing gravity feed and natural draft more effectively and efficiently burns pellet fuel while producing less air pollution and ash. In one embodiment, the pellet stove has a primary combustion area comprising a burn unit removably disposed in the vent tube, a feed tube defining a fuel chamber above the burn unit and a secondary combustion area, comprising a burn box defining a secondary burn chamber, below the burn unit. The burn unit has a removable receptacle which defines a primary burn chamber that receives pellet fuel from the fuel chamber and discharges substantially burned fuel to the secondary burn chamber for additional burning. Openings in the burn box, pellet receptacle and vent tube draw air into the burn chambers. A control mechanism controls the air flow to regulate the heat generated by the pellet stove. The pellet stove can be manufactured in various aesthetically pleasing designs.

Abstract: A biomass stove includes a housing enclosing a firebox that defines a ceiling portion opposite a bottom, a firepot disposed within the firebox, an air intake assembly coupled to the firebox, and at least one duct disposed entirely inside the firebox and extending between the ceiling portion of the firebox and the air intake assembly. The duct(s) provide a heat exchanging flow path for ambient air entering the air intake assembly, where the ambient air is heated within the duct(s) prior to exiting through the ceiling portion of the biomass stove.

Abstract: A method is provided for regulating the output of a solid fuel furnace having primary and secondary combustion chambers arranged adjacent to each other, in particular one above the other or side by side, and are separated from each other by a partition in the floor or wall but are nevertheless connected to each other by at least one partition opening. The secondary combustion chamber is connected through a secondary exhaust-gas channel to a flue-gas passage, and the primary combustion chamber is connected to the flue-gas passage by a transition opening, wherein the transition opening can be closed at least partially by a flue-gas flap. Both a primary air supply and a secondary air supply are provided. A first temperature sensor is arranged in the secondary exhaust-gas channel and controls the primary air volume flow as a function of the temperature in the secondary exhaust-gas channel, while the secondary air volume flow is held substantially constant.

Abstract: The present invention relates generally to 90% Annual Fuel Utilization Efficiency gas or oil burning devices that depend on external air for combustion. More particularly it discloses an alternate intake apparatus for air for combustion that opens automatically when the inlet air conduit from outside is blocked or severely restricted.

Abstract: Combustion apparatus for use with a solid fuel has a firebox constructed at least in part of a fired refractory carbide material. The fired refractory carbide material has a catalytic effect on the combustion process providing a cleaner and more efficient combustion. The fired refractory material also absorbs heat from the combustion process directly or indirectly by heat exchange with combustion products and dissipates the absorbed heat over an extended period of time providing space heating after the combustion process is completed.

Abstract: An oxygen flow controlling rear housing member for use in a burner comprises a main body portion with a first oxygen inlet. An annular oxygen gathering chamber is in fluid communication with the first oxygen inlet. An annular wall divides the annular oxygen gathering chamber and an annular oxygen-flow mixing chamber. A first oxygen flow passageway extends between the annular oxygen gathering chamber and the annular oxygen-flow mixing chamber, and has a first height that is a portion of the height of the annular wall. A second oxygen flow passageway extends between the annular oxygen gathering chamber and the annular oxygen-flow mixing chamber, and has a second height that is a portion of the height of the annular wall. The height of the first oxygen flow passageway is greater than the height of the second oxygen flow passageway.

Abstract: An improved wall thimble as part of a venting apparatus for a heating appliance. Dual functionality is provided in a single wall thimble device by having a vent path for exhausting combustion by-products, and a separate air inlet path to draw in combustion air for use by the heating appliance. The wall thimble is preferably formed as a two-cylindrical part housing such that a first portion can be inserted into a second portion. When a smaller exhaust pipe is routed through the two-part housing, an annular region is formed between the exhaust pipe and the walls of the housing. A first air vent is formed in the first portion to draw combustion air into the annular region from outside. A second air vent is formed in the second portion to route the combustion air from the annular region out through the second air vent to be coupled with the combustion air inlet. A baffle is disposed in the first portion to preheat the combustion air.

Abstract: A burner comprising a fuel reservoir, a primary combustion zone located at the lower end of the fuel reservoir, a secondary combustion zone located underneath the primary combustion zone, a passage providing communication between the primary and secondary combustion zones, a flue for discharging products of combustion from the secondary combustion zone, the primary combustion zone having a peripheral wall incorporating air hole means to provide combustion air to the primary combustion zone, wherein the cross-sectional area of the air hole means is substantially equal to the combined minimum cross-sectional area of the passage and the minimum cross?sectional flow area of the flue.

Abstract: A portable pellet fired heating element for mounting to a grill or stove and comprising a gravity fed pellet holder, a unitary tubular structure having a burner, an air intake and an exhaust chute. Fuel may be supplied to the pellet holder by various supply means such as a conveyer, ramp, scooped, held in bulk in a hopper, and like pellet supply structures and methods. Fuel is fed to the air-cooled insulated burner area onto a decomposer grate, which defines the primary combustion area and which is partially open to the atmosphere for air intake. An adjustable high-pressure flow of gas or vapor is introduced to the primary exhaust chute below the decomposer grate to create a low pressure flow above the grate and which upon ignition, cause flames to be pulled into the pellet mass on the grate.