Abstract: A plurality of dispersive air pipes for combustion (11) containing a plurality of dispersive air holes and projecting in a cantilever fashion from the side walls (1b, 1c) in an oblique downward direction are provided in the lower portion of a combustion zone (2b) of a furnace main unit (1) which includes an ash discharge outlet (6) formed in the base portion of the furnace main unit, and an incombustible material discharge space (12) is formed between the ends of the dispersive air pipes for combustion (11). As a result, incombustible material accumulating on the dispersive air pipes for combustion (11) is guided to the incombustible material discharge space (12) and then discharged.

Abstract: In a method of incinerating waste material in a parallel flow process wherein hot exhaust gases are conducted above a combustion chamber grate in the same direction as the material is moved on the grate, different temperatures zones are maintained to which air is admitted from the bottom through the grate such that a temperature of less than 900.degree. C. is maintained in a first zone which is a drying zone, a temperature of about 1000.degree. C. is maintained in a second zone which is an evaporization and vaporizing zone, a temperature of about 900.degree. C. is maintained to in a third zone, which is the final combustion zone and a temperature less than 900.degree. C. is maintained in a fourth zone which is a sintering zone. Additional air is supplied to the combustion zones 1 through the side walls of the combustion chamber.

Abstract: A process for the production of heat energy from solid carbonaceous fuels is disclosed which comprises subjecting the carbonaceous fuel to substantially anaerobic pyrolysis in at least one first zone and thereafter transferring the char resulting from the pyrolysis to a second zone which is segregated from the first zone or zones. The char is subjected to gasification in the second zone by introduction of primary combustion air, optionally with steam and/or recycled exhaust gas. The off gases from the second zone and the pyrolysis gases from the first zone or zones are thereafter subjected to secondary combustion and the first zone or zones is heated by heat derived from the secondary combustion. Ash is removed from the bottom of the second zone.

Abstract: A method and an arrangement for supplying air to a recovery boiler. In the method, the air is supplied to the recovery boiler at at least one air supply level so that four vortices are formed therein, the vortices spinning, in pairs, in opposite directions to one another so that any two adjacent vortices always spin in opposite directions to one another. The arrangement comprises nozzles that are arranged to blow air so that four vortices are formed in the recovery boiler, any two adjacent vortices always spinning in opposite directions to one another.

Abstract: A fluidized-bed thermal reaction apparatus burns or gasifies combustible matter containing incombustible components, so that deposition of incombustible components in a fluidized-bed furnace is prevented, and incombustible components are smoothly removed, thereby efficiently burning or gasifying the combustible matter. A weak diffusion plate, a strong diffusion plate, and an auxiliary diffusion plate, each have a large number of fluidizing gas feed holes. An incombustible component outlet is disposed between the auxiliary diffusion plate and the strong diffusion plate. A part of fluidizing gas is supplied from the incombustible component outlet, or the incombustible component outlet is provided to open horizontally. Thus, a continuous fluidized bed circulating stream is formed in the furnace bottom. The weak and auxiliary diffusion plates each has a downwardly inclined surface extending toward the incombustible component outlet.

Abstract: A method and apparatus retrofitted to a multiple-intertube pulverized-coal burner to reduce NO.sub.x emissions of roof fired boilers. An internal two stage process controls the amount of secondary air which flows to the burner. The first stage includes a secondary air damper and air flow station to regulate the amount of air which flows into a windbox of the burner. A baffle plate assembly which includes a plurality of baffle plates further limits the amount of air which flows to the core of the burner for combustion of the fuel. The baffle plates create a pressure drop within the windbox which forces or diverts a quantity of air to the periphery of the burner. The second stage includes an outlet formed in the hot primary air duct, an air plenum which communicates therewith, and a plurality of interjectory air ports which correspond with the burners in number and position along a front wall of the boiler and which communicate with the air plenum.

Abstract: A pellet fuel burner includes a compact thermally insulated firebox for providing hot gases to a boiler, furnace or dryer. The apparatus includes a grate that includes a reciprocating arm for removing clinkers and ash from the grate. Pellet fuel feed is provided by a hopper that is isolated from the firebox by an airlock. A combustion air manifold is provided around the firebox to preheat primary and secondary combustion air.

Abstract: An apparatus and method for burning organic farm bedding waste includes a firebox having an air injector disposed within the firebox. A heat exchanger is also disposed within the firebox above the air injector. The fuel to be burned, a mixture of organic farm bedding waste, is piled in the firebox surrounding the air injector and heat exchanger. By injecting air into the pile of fuel, the fuel is burned from the inside out, surrounding the heat exchanger with the burning fuel. The unburned fuel acts to insulate the burning fuel from the walls of the firebox. The apparatus can be used as an incinerator or as a furnace to heat a building.

Abstract: An air nozzle assembly for use in associated combustion apparatus which includes a first elongated housing having first and second axial extremities. The first axial extremity thereof is open to the interior of the first housing and tapers axially from a larger to a smaller cross section that constitutes a generally flat nozzle at the first axial extremity. A second elongated housing has first and second axial extremities. The fist axial extremity is open to the interior of the second housing, at least the first axial extremity and an axial portion of the second elongated housing are dimensioned and configured to extend with at least the first axial portion disposed within the first elongated housing. The first axial portion tapers axially from a larger to a smaller cross section at the first axial extremity. The apparatus also includes means for selectively preventing flow in the second elongated housing.

Abstract: Incinerator apparatus includes a furnace and a chimney in communication with the furnace. Within the furnace, a pipe having a bore and extending upward from the bottom of the furnace is disposed. The pipe is in communication with atmospheric air at the lower end thereof and is provided with a plurality of air holes therein. The pipe also includes a top air hole at the top end thereof. The top air hole has a transverse cross-sectional area smaller than that of the bore of the pipe. External air is spontaneously introduced from the outside of the furnace and flows out through the top air hole. As air flows out of the top air hole, it is also uniformly distributed through the air holes into the furnace and garbage to be burned in said furnace.

Abstract: A combustion system in which a coal/primary air mixture is discharged from burners located in the corners of the furnace towards an imaginary circle disposed in the center of the furnace. Air is discharged from air nozzles also located in the corners of the furnace in two flow streams--one directed towards the center of the furnace in a combustion-supporting relation to the fuel, and the other along the inner surfaces of the furnace boundary walls to maintain an oxidizing atmosphere and minimize corrosion and slagging.

Abstract: The present invention relates to a method for the combustion of waste liquids in connection with recovering of chemicals from the waste liquid, preferably black liquor from pulp production whereby the liquid (5A) is injected at a given level (4) into a furnace (1, 2, 3) in which the liquid (5A) initially is dried and the solid remainder thereafter is pyrolysed and finally burned and the chemicals are assembled on the bottom of the furnace while the exhaust gases (8) are going up through and out from the furnace (1, 2, 3) and whereby a part of the combustion air, so called primary air (11), is supplied at one or more levels (6) below said level (4) of liquid injection (5A) and another part of the combustion air, so called secondary air (12), is supplied at one or more levels (7) between said levels for liquid injection (4) and primary air supply (6) respectively, whereby the secondary air (12) is supplied to the furnace (1, 2, 3) in such a way that the gas is forced to rotate in a plane substantially perpendic

Abstract: A pellet stove or grill includes a housing (10) divided by a thermal barrier (43), which is defined by a spaced pair of partitions (20, 21), into a hot compartment (23) and a cold compartment (47). The hot compartment includes a ventilated firepot (44) suspended within an air channel (40) that communicates with the cold compartment through the thermal barrier. The cold compartment is subdivided by a funnel (22) into a fuel pellet storage compartment (24) thereabove and an electrical compartment (25) therebelow. The electrical compartment includes a motorized, fuel conveyer (37) for feeding fuel pellets (31 ) from the storage compartment, down a chute (38) that extends through the thermal barrier, and into the firepot in the hot compartment for combustion. The chute includes a portion that is positioned within and communicates with the thermal barrier. An air blower (34) drives fresh air into the electrical compartment and into the thermal barrier through an aperture (50) in one of the partitions.

Abstract: A method and apparatus for a pellet fuel burning heating unit for burning corn or wood pellets having a balanced pressure system having a four-way split combustion intake airstream. The invention includes a combustion air blower system for providing combustion air into a firebox containing a burner under positive pressure and at the same time providing a negative pressure to remove the combustion gases from the firebox. A pressure regulator and air splitter maintains a balance between the positive and negative pressure and adjusts the air flow into the firebox and out the exhaust. The exhaust is provided through a bank of exhaust tubes running from the top of the firebox to an exhaust manifold. The blower air moves into the pressure regulator and air splitter dividing the air flow such that a portion enters the heating unit exhaust manifold to produce a negative pressure and the remaining portion enters the heating unit burner under positive pressure.

Abstract: A pellet fuel burning heating unit having a firebox with a burner therein connected to a combustion air duct, an exhaust pipe to remove combustion gases from the firebox, a blower to provide combustion air and a pressure regulator and air splitter to divide the air flow from the blower into the combustion air duct and into the exhaust pipe. The air flow into the combustion air duct creates a positive pressure in the burner and the air flow into the exhaust pipe creates a suction of the exhaust gases in the firebox.

Abstract: The secondary air nozzle for furnaces has a curved base body which is provided with pins for holding a ceramic protective casing. A protective strip which projects radially from the base body is arranged along the longest line of curvature proceeding from the nozzle opening until beyond the curved part, its radial dimension corresponding at least to the thickness of the ceramic protective casing. The protective strip is constructed as a rib which projects radially from the base body and is outfitted with pins for supporting the ceramic body.

Abstract: A method of inhibiting formation of unburned substances in incinerating refuse is practiced with use of an incinerator wherein a peripheral wall defining a combustion chamber is provided with a nozzle for injecting at least one mixing fluid selected from the group consisting of air, water, water vapor, inert gas and combustion exhaust gas into the combustion chamber and producing a swirling stream of the fluid within the chamber. When the refuse is incinerated, the mixing fluid is injected into the combustion chamber from the nozzle, whereby the flame and unburned substances produced within the chamber are efficiently mixed with an excessive portion of air supplied to the chamber and remaining therein to ensure promoted complete combustion.

Abstract: This invention is directed to a method and apparatus for improving fluid flow and gas mixing in boilers. More particularly, this invention pertains to a method and apparatus for improved fluid flow and gas mixing in kraft recovery boilers for increased energy efficiency, reduced TRS emissions and increased capacity. The method of introducing air into a boiler furnace comprises: (a) introducing air through at least one opening located on at least a first wall of the interior of the furnace; and (b) introducing air through at least one second opening located on a second wall of the interior of the furnace opposed to the first wall at the same, or slightly different, elevations.

Abstract: A pellet burning heating device (20) designed to operate at a combustion efficiency of about 90-98% (based on the oxygen-derived combustion efficiency formula), and to emit exhaust gases having a carbon monoxide concentration, by volume, of about 0.04% or less, which device does not incorporate a fan system for introducing combustion air into, or extracting exhaust gases from, the stove. High combustion efficiency and clean burning are accomplished by providing a plurality of apertures (130, 132) in the burn pot (120) of the device having a predetermined size, number, and placement. The heating device (20) also includes an aperture (200) which provides a wash of relatively cool air to the inside surface of the window in order to reduce carbon deposits. A shaker (160) located in the burn pot (120) provides a heat sink which helps to increase the efficiency of the heating device.

Abstract: A method of preventing dust from adhering to a wall of a combustion apparatus, such as a furnace wall or exhaust duct, is carried out by forcing gas through a porous refractory member forming the wall. Specifically, the furnace wall or exhaust duct wall to which dust might otherwise adhere is made of a porous refractory member and gas is injected through the pores of the refractory member. In an incinerator, the refractory porous member extends around the periphery of a liquid injection nozzle, so that gas fed to the inside of the incinerator through the refractory porous member prevents flower from accumulating at the periphery of the end of the nozzle and attenuates the wake of the injected liquid so as to suppress the entrainment of dust in the liquid. In a melting furnace, the refractory porous members provide the ceiling of a slag separating chamber and the entrance of an exhaust gas duct open to the upper portion of the slag separating chamber.

Abstract: The present invention aims for the object thereof at preventing unburnt gas and noxious gas components from being generated in a refuse incinerator, and provides a combustion control method by which it is arranged so that a feeder (2) and a stoker (3) are not only controlled so as to keep evaporation (S1) of the boiler at a target value thereby to achieve stabilized combustion extending over a long period of time, but also feed water quantity (S2) and the like from a boiler water pipe section (2) forming a combustion chamber (6) are detected, and the rate of overfire air quantity to main combustion air quantity to a lower part of the stoker is controlled at a constant total gas capacity so that the fluctuation width of the feed water quantity (S2) falls within a set range.

Abstract: An incinerator designed so that the reaction of unburnt gas with oxygen progresses rapidly to thereby minimize the amount of unburnt gas generated therefrom. An intermediate portion of a combustion chamber is contracted in the cross-sectional direction with respect to the direction of flow of gas to thereby provide a throttling passage (14) over a predetermined distance. A part of the combustion chamber which is below the throttling passage (14) and a part of the combustion chamber which is above the passage (14) are enlarged in the cross-sectional direction to define a lower combustion chamber (13) and an upper combustion chamber (15), respectively. A first barrier (16) is disposed in the vicinity of the inlet of the throttling passage (14) across the lower combustion chamber (13) and a second barrier (17) is disposed in the vicinity of the outlet of the throttling passage (14) across the upper combustion chamber (15).

Abstract: An incinerator of sectional structure has an airpipe for sending combustion air into a furnace. The airpipe is a straight pipe tapered off at end portion and closed by a plug of castable refractory material filled up in the tapered portion to improve the durability under high temperature circumstances. The airpipe is also inserted into a furnace through a hole opened on an upper furnace wall, and a seal member of easy spallable and castable refractory material fills up the gap between the airpipe and the hole to make easy exchange of the airpipe possible.

Abstract: The secondary air jets (11) that are arranged within the combustion space (5) consist of an outer casing (12), an inner casing (13), and a flange (14) that connects the two casings to each other, the flange (14) crossing the inner casing (13) and being rigidly connected with this, whereas the outer casing (12) is so connected to the flange that is of greater diameter than the outer casing (12) that slot-type jets (15) are left between the face side of the outer casing (12) and the flange (14), these jets making it possible to expel air parallel to the defining wall and essentially perpendicular to the axis of the jets.

Abstract: The invention relates to a combustion device for wood or coal comprising a front wall with a fuel charging opening, two side walls, a rear wall, a bottom wall, a top wall, a door for the fuel charging opening, a control element for controlling a fresh-air inlet opening, an inner dividing wall which divides the interior of the device into a pre-combustion chamber and a post-combustion chamber, and a passage opening between the two chambers and a grating at the bottom of the pre-combustion chamber and a flue gas discharge opening; the dividing wall is horizontally disposed and a shaft pipe surrounded by an annular chamber which is in communication with the fresh-air inlet opening is inserted sealingly into its passage opening; the grating is placed on its upper end.

Abstract: A pellet burning heating device (20) designed to operate at a combustion efficiency of about 90-98% (based on the carbon derived combustion efficiency formula), and to emit exhaust gases having a carbon monoxide concentration, by volume, of about 0.04% or less, which device does not incorporate a fan system for introducing combustion air into, or extracting exhaust gases from, the stove. High combustion efficiency and clean burning are accomplished by providing a plurality of apertures (130, 132) in the burn pot (120) of the device having a predetermined size, number, and placement. More specifically, the total area of the apertures in the bottom wall (122) and portions of the sidewall (124) at or below the pellet level (134) in the burn pot is equal to the total area of the apertures in the sidewall positioned above the pellet level.

Abstract: A process for combusting low B.T.U. high moisture content fuels by enriching the normal process air used in the combustion process.

Abstract: A method and apparatus for introducing combustion air in the form of air jets into a furnace (2) of, for example, a soda recovery boiler. Combustion air is introduced through air ports (12), arranged substantially at the same level (10), in air jets (13) of at least two sizes. Air ports in the walls (4) of the furnace are dimensioned in different sizes such that their hydraulic diameters increase from the corners of the furnace towards the centers of the furnace walls, whereby the degree of penetration of the respective air jets flowing through the air ports increases. The penetration of the air jets in maintained constant at different loading conditions.

Abstract: A clustered concentric tangential firing system (12) particularly suited for use in fossil fuel-fired furnaces (10) and a method of operating such furnaces (10) equipped with a clustered concentric tangential firing system (12).

Abstract: In a combustion air supply system, particularly a secondary air supply system for a recovery furnace, the secondary air inlet ports are divided into two arrays in such a manner that the combustion air coming in through the inlet ports of the first array is directed in part to contact and in part to by-pass a central region in the outer surface of a carbonization layer. The combustion air coming in through the inlet ports of the second array is directed to by-pass the combustion air coming in through the inlet ports of the first array thereabove. The first and second arrays are located on the opposite walls of the combustion chamber, preferably on the front and rear walls. The recovery furnace further comprises a primary air supply zone for blowing combustion air onto the sides of the carbonization layer and a tertiary air supply zone above a waste liquor inlet.

Abstract: Apparatus for regulating air flow through an air port in a chemical recovery furnace. A plenum having an adjustable damper mounted inside a wind box associated with the furnace adjacent to the air port supplies and regulates the flow of air from the wind box to the furnace through the air port. A metal cleaning head adapted for rotatable insertion into the air port for cleaning excrescent material from the peripheral edges of the air port without blocking air flow through the port is pivotally mounted in a retracted, at-rest position adjacent to and above the air port so as not to interfere with movement of the adjustable damper. During a cleaning cycle, the damper is moved to a retracted position on the floor of the plenum so as not to interfere with the moving cleaning head. A short stroke, double articulated damper positioning mechanism facilitates movement of the damper blade in limited space.

Abstract: The specification describes a system for initiating and promoting combustion of fuels such as wood, coal, oil, etc. Virtually complete combustion is achieved by feeding combustion air under pressure through openings in a diffuser plate with the diameter of the opening having a calculated size and spacing therebetween. By-products of primary combustion are burned by the system. The specification also describes an exemplary wood stove and a cooking unit which utilizes the novel combustion principle.

Abstract: A primary combustor of waste solids, wherein the solids are burned under sub-stoichiometric air control and then substantially immediately merged with the burning zone in a secondary combustor wherein waste fluids are burned with excess air and substantial waste heat recovered in the form of an energy resource such as steam.

Abstract: An incinerator, comprises a combustion chamber having a pair of opposed side walls and a top outlet passage. Primary air is injected into the combustion chamber through the floor and air jets located in each side wall adjacent the outlet passage direct air streams across the chamber above the material being burned. The air jets on one of side walls are longitudinally offset relative to the air jets on the other side wall along the length of the chamber so that the air streams traversing the chamber from one side wall do not directly interfere (except at their outer peripheries) with the air streams from the other side wall and the air streams as they approach the side walls are directed downward toward the bottom of the chamber and tend to flow into and upwards along the surface material being burned.

Abstract: A method and apparatus for burning a combustible material in a closed container having an open top wherein a sheet of oxygen containing gas is forced into the burning chamber of such container, wherein, in forming the sheet of oxygen containing gas, a majority of the gas which is to be formed into a sheet is forced away from the central section of the sheet towards the end sections of the sheet that are situated on either end of the central section and wherein the interior volume of the burning chamber can be varied by use of a movable wall means so that the combined effect of the gas sheet formed in the foregoing manner and the adjusted internal volume of the burning chamber in relation to the specific material to be burned yields an efficient combustion process as evidenced by minimal production of opaque smoke.

Abstract: An incinerator having a funnel shaped burning chamber within a firebox with the chamber being formed of water pipes connected to a water circulation system including a steam chest. The chamber is rotated about its axis which is inclined so that the lower conical portion of the chamber is horizontal. Material for burning is driven up the cylindrical portion of the chamber, and combustion air is forced through a nozzle into the open conical portion of the chamber.

Abstract: Removable apparatus for regulating air flow through an air port in a chemical recovery furnace. A plenum mounted adjacent an air port inside a wind box associated with the furnace supplies combustion air from the wind box to the furnace through the air port, and an adjustable damper mounted inside the plenum regulates the velocity and quantity of air flowing through the plenum. An access port in the plenum allows viewing of the air port opening through the plenum. An actuating mechanism withdraws the damper from the field of view to a retracted position wherein the damper depends from the top of the plenum chamber spaced apart from the air port opening. For airflow damping, the actuating mechanism moves the retracted damper toward the air port opening until the damper is adjacent to the opening; then a positioning mechanism pivots the damper to a predetermined position in the air stream adjacent the opening.

Abstract: Removable apparatus for regulating air flow through an air port in a chemical recovery furnace. A plenum having an adjustable damper is mounted inside a wind box associated with the furnace adjacent to an air port and supplies and regulates the flow of air from the wind box to the furnace through the air port. A metal cleaning head having a cage-like configuration is pivotally mounted in a retracted, at-rest position inside the plenum above and adjacent to the air port so as not to interfere with movement of the adjustable damper.

Abstract: In a steam generating boiler having a bottom wall supporting a char bed and sidewalls with ports through which air is admitted for combustion of combustible species in the char bed and emanating therefrom, combustion is improved by introducing an oxygen-containing gas into a lower central zone of the boiler, from at least one point remote from the sidewalls to thereby cause intimate mixing of the oxygen contained in the gas with the combustible species.

Abstract: The incinerator comprises a combustion chamber (14) comprising a lower grate (40) and an outer wall (34), a device (24-32) supplying the materials to be incinerated, a primary air (44,46) blower casing (42) situated in the center of the grate, and a secondary air circuit (50,52) comprising injection nozzles (48) distributed on the periphery of the combustion chamber. Some at least of the nozzles are formed of nozzle pairs (48a,48b) oriented according to a first angle above and under a horizontal plane and according to a second angle on either side of a vertical diametral plane.

Abstract: The present invention relates to a gasification burner for heating apparatus (boiler, hot air generator or the like) which uses solid fuel. The gasification burner is placed generally at the center of the hearth of the heating apparatus to achieve gasification of the solid fuel before its transformation into charcoal or coals.

Abstract: An air supply nozzle for a fluid bed furnace comprises a tubular member attachable to a plate, forming the bottom of the furnace. The tubular member is upwardly closed by a lid and just below the same a number of air dispersing openings are provided. A wear-resisting ring of hard metal is attached to the upper end of the tubular member and has a thickness and a height noticeably exceeding the wall thickness of the tubular member. The void within the ring is filled with refractory concrete so a dome projecting above the ring is formed. The tubular member includes a un-perforated portion, which has such an extension that the tubular member, after a hard wear, may be cut, a lower stub of the tubular member remaining at the plate, while the top is substituted by a new portion. The two portions of the reconditioned tubular member are then connected by an internal supporting sleeve and tack welding.

Abstract: An air blower is used with an open fire incineration pit dug below ground level. The blower includes a motor and a fan driven by the motor. A plenum chamber receives air from the fan and has a cross-sectional shape of at least three sides including a flat base flush with the ground level and a front side sloping away from the pit. Preferably, the plenum chamber has a trapezoidal cross-section. A nozzle connected to the plenum chamber jets an air curtain over the open fire in the pit. A protective fence attachable to the plenum chamber surrounds the pit. Also, there may be one or more telescoping sections slidable out of either one or both opposite ends of the plenum chamber for jetting additional air curtains over the open fire in the pit.

Abstract: Apparatus for supplying an air curtain into a pit to facilitate combustion of material disposed within the pit includes an air supply tube mounted on wheels and having an inlet end and an outlet end, a nozzle structure disjointably mounted on the air supply tube at the outlet end thereof and in transverse relation thereto, a motor driven fan for supplying air through the air supply tube and the nozzle and into the pit, the junction between the air supply tube and the nozzle being readily disjointable to accommodate mounting of the nozzle atop the air supply tube for transport along a roadway.

Abstract: Method and apparatus for infrasonically intensifying a glow bed (13), supported by a grate (12). In order to improve the beneficial effect of sound on combustion the bed of fuel, located on the grate, is exposed to a high particle velocity of a sound positively produced by an external low frequency sound generator (11) the frequency of which is determined by the sound generator, to provide a reciprocating movement of combustion air and combustion gas through the glow bed. The dimensions of the grate in a plane transverse to the reciprocating movement of combustion air and combustion gas are less than a quarter of the wave-length of the sound generated by the sound generator.

Abstract: A chemical recovery furnace (10) having air nozzles (12) is provided with apparatus (22) for keeping the nozzles clear of combustion product deposits, and also accurately controlling the airflow through such nozzles. Each nozzle has slots (20) in the sidewalls thereof, which slots are of decreasing width, the smallest width (38) being closest to the furnace. A plug (22) is slidable within each nozzle to control airflow, and also remove deposits from within the nozzle.

Abstract: The location of an air supply in a combustion apparatus is made adjustable by changing the point of intersection of a slot in a movable surface with a slot in a fixed surface. In the preferred embodiment, the fixed and movable surfaces are of tubular construction. Variations include a second movable surface for the purpose of extending the range of adjustment, and the use of discrete holes rather than slots in the fixed and movable surfaces.

Abstract: A rectangular air inlet control plate is pivotably mounted in the air intake passage of a forced air furnace to control the air intake volume and, thereby, insure optimal combustion of the fuel in the furnace. The plate is adjustably counter-balanced to a closed position and is further adjusted to allow the optimum volume of air intake during operation of the forced air furnace. The rectangular shape of the plate provides for fast opening and closing of the air intake during startup and shutdown transients, since the actuation angle of the plate is reduced in proportion to its length. The plate is mounted in a funnel-shaped air intake structure to reduce the noise and allow a maximum volume of air to enter the intake. A windscreen is mounted on the funnel-shaped air intake in order to act as a turbulence breaker for the incoming air, and also to prevent ingestion of large debris into the air intake.

Abstract: The furnace has a feeding channel (4) through which firewood is transported into a fire chamber (3). A steam pipe (10) leads into the channel (4). Through said pipe (10), steam is introduced into the solid fuel material in bursts as soon as a certain temperature is exceeded within the said channel (4). The steam increases the humidity in the air and the moisture of the firewood, thereby reliably preventing a spreading of the fire within the feeding channel (4), without simultaneously impairing combustion within the fire chamber (3).

Abstract: A maximum efficiency stove or furnace for heating homes or other buildings. The stove includes a primary combustion area for burning a primary fuel, such as wood, and secondary combustion areas for burning the gases of combustion after they leave the primary combustion area. The combustion chambers and areas are at least partially surrounded by air heating enclosures through which ambient room air is forced, preferably by a fan, for heating. Air for sustaining combustion is preheated in a preheating chamber and fed through separate intakes to both the primary and secondary combustion areas. A single draft control is provided to control air flow through the preheating chamber and to simultaneously control the flow of preheated air to and through both said primary and secondary combustion air intakes.