Abstract: A solid fuel burning hot water heater is described having a primary combustion chamber with a refractory material base portion which forms the locus of combustion. A water jacket defines an upright portion over the refractory base portion for receiving a charge of fuel in a generally vertical stack. The water jacket is coupled to a source of water for at least convection circulation and assists in confining the locus of solid fuel combustion to the base of the chamber. Heat exchange channels or pathways are defined around the outer periphery of the water jacket in heat exchange relationship with the water jacket for transfer of heat from the end products of combustion to the circulating water. A flue gas delay channel arrangement extends from the draft outlet at the base of the combustion chamber to the heat exchange pathways.

Abstract: A gas-fired, forced air furnace system employing a fiber matrix burner element and a condensing-type heat exchanger to achieve both high system thermal efficiency and low emission of NO.sub.X and other gaseous pollutants. The value of excess air in the fuel-air reactants supplied to the ceramic fiber matrix burner is selected to be equal to or greater than ten percent to provide NO.sub.X emissions below fifteen ppm on an air-free basis, with CO and HC emissions substantially comparable to those from existing furnaces, and the surface area of the condensing portion of the heat exchanger system is designed to produce sufficient condensation of moisture in the combustion gasses to produce an overall system thermal efficiency of at least about ninety percent.

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

Abstract: A method for minimizing the amount of nitrogen oxide pollutants produced in a process for firing a furnace using oxygen or an oxygen-enriched gas as the oxidant, in which furnace gases are aspirated into the oxidant jet prior to combustion and in which the furnace is operated using alternating low firing rate and high firing rate periods, by delaying the injection of oxidant at the high rate at the start of the high firing rate period.

Abstract: An apparatus is provided for generating heated air, for example, for use in connection with a dryer for particulate material, comprising a base portion having a combustion chamber and a burner for providing a flow of combustion gas. A plurality of open tubes having the first ends communicating with the combustion chamber are provided for receiving the flow of combustion gas. The second ends of the tube extend beyond the base portion. A tubular structure is connected to the base portion surrounding the second ends of the tubes. The tubular structure has partition means for dividing it into a heat exchange chamber adjacent the base portion and surrounding the tubes and a manifold chamber remote from the base portion. The partition cooperates with the tubes to direct the flow of combustion gas into the manifold chamber.

Abstract: A boiler has a chamber to contain a charge of wood that rests on the bottom of the chamber with the major portion of the charge within a water jacketed upper portion of the chamber but free to settle as combustion progresses. Combustion is confined to the bottom portion of the chamber due to the cooling effect of the water jacket and to a turbulent cross draft in the combustion zone. A special venturi section in the flue coupled with a pressure blower both induces the flow of hot gases from the combustion zone through a second chamber and a heat exchanger and also provides a stream of air from the venturi section to create the cross draft. An oil burner may be used in conjunction with the second chamber as an alternate heat source. The boiler also has a special base construction and assembly features.

Abstract: A wood furnace permits controlled combustion of sectors or segments of wood-type fuels for a high turn down ratio. The primary combustion chamber comprises a refractory base portion for high temperature combustion and an upper portion with a water jacket in heat exchange relationship with the upper portions of the fuel for quenching combustion. A plurality of refractory secondary combustion channels or a single laterally extending or distributed secondary channel leads away from the refractory base portion of the primary combustion chamber. The secondary channels or distributed channel conduct flue gases from different sectors of the fuel, and permit completion of combustion in a high temperature environment. A plurality of flue draft pathways lead from the secondary combustion channels or distributed channel for transfer of heat from the end products of combustion to a heat transfer medium. Separate dampers are provided for controlling the draft in the separate flue draft heat exchange pathways.

Abstract: An attachment for a building furnace which contains a combustion unit inside of an air plenum. The attachment is inserted as a replacement section of the smoke flue. The jacketed chamber acts as a heat exchanger, preheating incoming combustion air. The outer end lower portion of the jacketing chamber receives a fresh air duct from the outside of the building. A duct from the outer end upper portion of the heat exchange chamber leads into the lower portion of the combustion unit plenum at the burners. Attached to the smoke flue, and between it and the outer portion of the chamber, are longitudinally-oriented channeled elements for transferring sensible heat. A return duct from the heated living area leads into the furnace, terminating at the inlet of a blower in the bottom of the furnace. The outlet of the blower is upward into the space surrounding the combustion unit. Such space also joins above the latter to lead upwardly into the heated living area.

Abstract: An apparatus for heating a fluid, as air, having a housing surrounding a heat transfer chamber. A casing having a combustion chamber is located in the heat transfer chamber. A motor driven fan mounted on the housing operates to supply air to the combustion chamber and move air through the heat transfer chamber. Fuel, as waste oil, is metered to the combustion chamber and burned. The air supplied to the combustion chamber moves the burning fuel in a circular pattern to promote combustion of the fuel adjacent the casing thereby heating the casing. The air moved through the heat transfer chamber picks up heat from the hot casing. The heated air is discharged through an open grill into the environment surrounding the apparatus.

Abstract: The damper is a hollow sheet metal duct-like device of generally rectangular cross section, and is adapted to fit over the combustion air intake of a furnace blower so that the furnace must obtain its combustion air through said damper. A trap door type valve in the lower surface of device automatically opens in response to the suction of the blower to admit combustion air, and automatically closes due to gravity when said blower is de-energized, to cut off the air supply to the furnace combustion chamber when the furnace is not operating.

Abstract: A controlled air intake apparatus for a furnace includes a substantially flat cover plate attached to and placed over the updraft opening of the flue and a generally rectangular housing attached over the air intake opening adjacent the burner region. The housing includes a first open side and opposite thereto a side including a plurality of apertures. The remaining sides of the housing are enclosed. The first plurality of apertures are disposed into two rows and the housing further includes a cover plate with a similar arrangement of apertures. The cover plate is slidably received by the housing and is movable by means of a solenoid between an aperture-closed orientation and an aperture-open orientation.

Abstract: A hot air furnace has an outer housing and a firebox positioned within the housing. A space between the outer housing and the firebox defines a pre-heating chamber which communicates through an air distribution blower to a lower chamber and an upper chamber within the housing. The walls of the firebox are hollow and open into the lower chamber and the upper chamber so that air extracted by the distribution blower from the pre-heating chamber and directed into the lower chamber is heated as it is channeled up through the hollow walls of the firebox prior to entering the upper chamber. A smoke chamber is located within the upper chamber and it serves to further heat the air entering the upper chamber. A combustion air blower is provided and it together with the distribution blower is automatically controlled by a thermostat located within the space to be heated.

Abstract: A furnace for the burning of wood in a combustion chamber to generate heat. Primary air is brought in at a grate level of the furnace. Secondary air is brought in through a secondary air inlet, past a preheat chamber and through a secondary air duct to be expelled through holes in the secondary air duct at the top level of flames. The secondary air is preheated in the preheat chamber which is located between the combustion chamber of the furnace and the outside air inlet. A heat exchanger in the top of the oven transfers the heat from the combustion chamber of the furnace to ductwork for distribution.

Abstract: A stove construction including a firebox that defines a combustion chamber. Air is supplied to the upper portion of the combustion chamber through a preheat manifold having outlet apertures spaced along the sides. Air is drawn from the atmosphere into the manifold where it is preheated and discharged in the form of jets toward the sloping side walls of the firebox and into the flow path of the waste gases of combustion. Due to the restriction to flow caused by baffles located in the spaces between the sides of the manifold and the sloping sidewalls, a portion of the mixture of air and waste gases is directed downwardly along the surface of combustion plates, which are spaced from the walls of the firebox, back toward the primary combustion area. The waste gases are further combusted as they pass downwardly along the heated combustion plates. The recirculation achieves complete combustion of the waste gases.

Abstract: A heating system for dwellings or other enclosures includes a furnace in which a burner is isolated from a hot air or water system, and receives substantially all of its combustion air from outside the enclosure and preheated. A heat exchanger is provided between exhaust gases from the burner of the furnace and the combustion air.

Abstract: A heating system for dwellings or other enclosures includes a furnace in which a burner is isolated from a hot air or water system, and receives substantially all of its combustion air from outside the enclosure and preheated. A heat exchanger is provided between exhaust gases from the burner of the furnace and the combustion air.

Abstract: A gas burning furnace system is disclosed, including a blower which draws air from outside the home for combustion. The blower forces combustion air to the gas burner via a pressure box situated between the blower and the burner. The pressure box encloses a barrier having an adjustable aperture therein, through which the combustion air must pass before reaching the burner. By adjusting the size of the aperture, the rate of supply of combustion air to the burner can be regulated so as to produce complete fuel combustion without cooling the firebox.

Abstract: A stove or furnace for combusting and extracting heat from wood and wood-type fuels includes a firebox arrangement for primary combustion and a flue structure coupled to the firebox which includes a plurality of flue gas decelerating chambers for slowing propagation of flue gas, heat exchange to the environment, and further combustion of fuel constituents in the flue gas. The chambers are coupled in series through restricting and accelerating passageways for maintaining draft between chambers, finally leading to an outlet chimney. The chambers are formed with baffles for greater turbulant mixing, combustion, and heat exchange. Furthermore, a tubular conduit may be provided extending from the firebox through the flue structure chambers. The tubular conduit is formed with orifices for injecting burning flue gas from the firebox primary combustion directly into the series coupled chambers to enhance secondary burning.

Abstract: A balancing air device for a heating unit in a building having a flue for the passage of waste combustion gases from a combustion chamber of the heating unit into a stack capable of having a draft flowing therein, comprising, a fresh outside air line connected to the combustion chamber of the heating unit for supplying air from outside the building and an air return line connected directly between the outside fresh air line and the stack for returning air supplied from outside the building to the stack when the heating unit is not operating. The cross-sectional flow areas of the outside fresh air line extending to the combustion chamber and the air return line are chosen so that, when the heating unit is not operating, the air return line satisfies a substantially constant draft flowing in the stack so that fresh outside air is not supplied to the combustion chamber when the heating unit is not operated.

Abstract: An outside air system and combustion chamber closure assembly for use with a fireplace which provides means for supplying sufficient amounts of cooling air between the burning fuel and the closure assembly is disclosed. The closure assembly includes a frame surrounding the combustion chamber opening and at least one door operably mounted thereto. A grille is formed in the bottom rail of the frame for introduction of air into the combustion chamber. The outside air system includes an outside air duct which is coupled to a chamber defining an air plenum formed below the hearth of the fireplace and air cap assembly. The air cap assembly is positioned against the bottom rail of the frame and extends across the combustion chamber opening. The assembly includes a duct which communicates with the chamber defining the air plenum formed below the hearth and an air discharge housing positioned adjacent the bottom rail.

Abstract: An improved downdraft furnace wherein two combustion grates are used, with the lower one being maintained completely covered with glowing coals, which totally oxidize combustion gases and particles passing through, with the result that the exhaust is free of smoke.

Abstract: A controlled air intake apparatus for a furnace includes a substantially flat cover plate attached to and placed over the updraft opening of the flue and a generally rectangular housing attached over the air intake opening adjacent the burner region. The housing includes a first open side and opposite thereto a side including a plurality of apertures. The remaining sides of the housing are enclosed. The first plurality of apertures are disposed into two rows and the housing further includes a cover plate with a similar arrangement of apertures. The cover plate is slidably received by the housing and is movable by means of a solenoid between an aperture-closed orientation and an aperture-open orientation.

Abstract: A solid fuel furnace is disclosed as including a firebox disposed inside of a heating chamber through which air to be heated is passed. A pair of baffles guides the air through the heating chamber to progressively heat the air. In addition, an auxiliary air system is provided to inject air into the fire when there is a heating demand to increase combustion and provide more heat when it is most needed.A modified solid fuel furnace is also disclosed which includes a combustion chamber having a door designed to prevent flash-back when the door is opened, a valve for preventing a flow of combustion air to the combustion chamber when the temperature in the combustion chamber rises above a present level, and a manual override for the valve.

Abstract: A heating apparatus is disclosed wherein a combustion chamber which contains the fuel to be burned is located adjacent to an air heating chamber. Conduit means communicate from the air heating chamber to the combustion chamber for the purpose of leading air, which has been heated within the air heating chamber, into the combustion chamber. Blower means draw ambient air from the space surrounding the heater into the air heating chamber where it is blown through the conduit means into the combustion chamber to promote efficient combustion of the fuel.

Abstract: A passive type of space heater having a vertical air heating duct located at the rear of the combustion chamber and a flue duct extending through the air heating duct with its inlet located so as to draw the flue gases from the combustion chamber around the surfaces of the air heating duct. Air for combustion is supplied to the top of the combustion chamber by an air supply duct which extends inside of the flue duct and has orifices to provide air in the flue duct for secondary combustion of the flue gases passing through the flue duct. The air supply duct also has an ejector to draw a portion of the flue gases into the air supply duct for recirculation to the combustion chamber for tertiary combustion. A separate air supply duct is provided for supplying air for combustion during start-up.

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

Abstract: An improved heat exchanger (74) for use with a heating furnace (72) is disclosed. The exchanger (74) includes a first plurality of tubes (84) which conduct hot exhaust gases from the furnace (72). Tubes (98) carrying outside air for combustion in the furnace (72) pass proximate the first group of tubes (84) within a heat exchange chamber (90) wherein heat is transferred to the combustion air via a heat transfer medium. Similarly, ambient air in the building passes through the heat exchange chamber (90) of the exchanger (74) through a third plurality of tubes (118). These tubes (118) also pass proximate the tubes (84) carrying hot exhaust gases. In a preferred embodiment, a conduit (80), through which the exhaust gases transit from the furnace (72) to the first plurality of tubes (84) in the heat exchanger (74), can be routed through plenums (110, 126) through which combustion air and ambient air circulate after exiting the second and third pluralities of tubes (98, 118).

Abstract: A wood-burning furnace including a combustion chamber having a novel combustion air distribution system including jets whereby air is delivered only to a limited portion of the area of the fire bed, and whereby clogging of the jets by the large quantities of wood ash is prevented, the combustion air being delivered by a thermostatically controlled blower and damper system such that the heat delivered by the furnace may be controlled and regulated with substantially the same degree of accuracy as that obtainable with gaseous and liquid fuels.

Abstract: A wood burning combustion heater comprises a combustion chamber for long logs arranged to burn down from one end to the other in cigar-like fashion, an after-burner tube arrayed above and essentially parallel to the elongated logs with the air and burned gasses following an S-shaped path through the combustion chamber and out through the exhaust tube, an after-burner within said tube and a heat exchanger fed by the exhaust from said tube for heating air in indirect heat exchange and characterized further by an incoming air passage annulus surrounding the combustion chamber for pre-heating thereby; multiple levels of air admission for controlling combustion; electric ignition at the after-burner; bathing the exhaust tube, containing the after-burner, in flame through admission of secondary air to the region outside such tube; and high mass for even dissipation of heat.

Abstract: A modular furnace for adaptation to a conventional domestic heating system includes a firebox which is enclosed on both sides, the top and the bottom. The front portion of the firebox includes an access door for introduction of the combustible fuel onto a grate, and the back of the firebox includes a first opening for an air inlet tube and a second opening for air flow beneath the grate. The inlet tube extends above the grate and provides a single air outlet adjacent the front portion. Surrounding a majority of the firebox is an external housing and extending up the sides and front portion of the firebox between the firebox and the housing are a plurality of air flow passageways. These passageways extend across a V-shaped finned heat exchange plate which comprises the top of the firebox. Heat from the heat exchange plate is convected to circulating air which then exits from the furnace by means of a conduit which is suitable for adaptation to the main heating duct of a conventional domestic heating system.

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.

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

Abstract: A solid fuel burning system which may be readily combined with a conventional fluid fuel burning furnace in a forced air heating system. The solid fuel burning system comprises, in combination, a draft inducing blower which directs air for combustion into the furnace at a point proximate the burning fuel. Baffle walls are provided which separate the smoke and other products of combustion from the clean air to be heated and a novel heat exchanger comprised of a plurality of elongated tubes provide a relatively large heat transfer surface. The furnace is specifically designed to facilitate periodic cleaning of the interior walls of the heat exchanger where creosote and other products of combustion may accumulate. In addition, the system employs a novel electronic control circuit which is tied in with the room thermostat and with a thermocouple disposed within the solid fuel burning furnace.

Abstract: In a home heating system having a furnace with a combustion chamber for burning fuel and creating heat, and a chimney with a draft therein, an improvement comprising, an exhaust flue connected between the combustion chamber and the chimney for venting heated exhaust products from the furnace, a heat reclaimer connected into the exhaust flue between the combustion chamber and the chimney for reclaiming heat from the heated exhaust product, and an outside air line for supplying air from the outside of the house to the combustion chamber. A first flue portion of the exhaust flue is connected between the combustion chamber and the heat reclaimer, and a second insulated flue portion of the exhaust flue is connected between the heat reclaimer and the chimney. An outside air by-pass or balancing line is connected between the outside air line and the chimney for satisfying the chimney suction at flame-out.

Abstract: The method disclosed includes positioning a furnace disposed within a shelter outside near the building, the shelter has an inlet for receiving ambient air and an outlet for passing air heated by the furnace out of the shelter. An air duct is mounted between the shelter and an opening into the building. A solid fuel is burned within the furnace to heat the air within the shelter and the heated air is transported through the duct into the building to provide supplemental heat in the event the supply of fluid fuel is interrupted.The apparatus disclosed includes a shelter having walls with an inlet for receiving ambient air and an outlet for passing heated air out of the shelter. A furnace is disposed within the shelter for heating the air and includes a grate for supporting solid fuel to be burned and an exhaust stack extending through the walls of the shelter for carrying exhaust gases from the furnace without mixing with the air within the shelter.

Abstract: A furnace shell has a fire pot centrally located therein, the walls of the shell and fire pot being spaced to form a fluid heat transfer chamber therebetween. Heat transfer is effected between the pot and the chamber to heat the fluid medium in the chamber. The shell is located in an interior to be heated, such as a building or home, including mobile and motor homes. An inlet conduit has a first end exteriorly positioned of the building interior and a second end substantially pneumatically sealed from the interior and in fluid communication with the fire pot enclosure to provide combustion supporting fluid exclusively from the exterior. A flue has a first end positioned exteriorly of said interior and a second end positioned in the upper portion of the fire pot enclosure to conduct combustion gases to the exterior. The flue is pneumatically sealed from the interior to prevent combustion gases from entering the interior.

Abstract: A self-cleaning heat exchanger in combination with a home furnace system which draws combustion air from outside the home is disclosed. Gases of combustion are drawn up through a plurality of vertical tubes and out a chimney by a fan mounted in the chimney. The lower portions of the tubes are cooled by inside air drawn over them by the return air blower of the furnace, the upper portions of the tubes are cooled by cold outside air drawn across them by the furnace burner unit. Moisture which condenses in the upper portions of the tubes is drawn down through them by gravity. The higher temperature in the lower part of the tubes causes this condensate to revaporize and rise to the upper portion of the tubes, where the process repeats itself. As more water vapor enters the tubes in the flue gas, distilled condensate eventually drops out of the tubes and runs into a drain at the lower end of the heat exchanger.

Abstract: This invention provides a device for use with oil or gas fired furnaces in buildings and more particularly homes to enchance heat efficiency, the device being adapted for installation in an air supply leading from outside the building to the furnace cold air return so that outside air passes through the device, the device including a cylindrical inlet portion, means of defining a chamber attached to the downstream end of the inlet portion and having an internal cross section larger than that of the inlet portion, a frustro-conical section coupled to the chamber means remote from the inlet portion for carrying air from the chamber towards the furnace and converging towards the furnace, a valve assembly to adjust air flow and a baffle plate fixedly positioned at the junction of the chamber means and the frustro-conical section to combine with the valve assembly to inhibit sudden air flow changes caused by pressure fluctuations.

Abstract: A solid fuel furnace is disclosed as including a firebox disposed inside of a heating chamber through which air to be heated is passed. A pair of baffles guides the air through the heating chamber to progressively heat the air. In addition, an auxiliary air system is provided to inject air into the fire when there is a heating demand to increase combustion and provide more heat when it is most needed.

Abstract: A combustion air sytem for wood fired boilers, furnaces, stoves and other heating apparatus; the combustion air system including an air-tight combustion chamber, within which a wood fuel is burned upon a grate, primary air being introduced from below the grate, so as to burn the wood, and a secondary air being introduced into an air conducting tube in the crown sheet of the combustion chamber, which mixes with volatile gases from the burning wood, so as to burn the same, and produce additional heat.

Abstract: A wood and oil burning furnace having a combustion chamber in which logs are laid for burning, a baffle plate across a substantial portion of the top of the combustion chamber, a combustion gas outlet at the top of the chamber, a plurality of secondary air inlet tubes in the upper portion of the combustion chamber, a fan and secondary air preheating chamber in one wall of the combustion chamber and supplying preheated air to such tubes, and oil or gas burner, an auxiliary chamber connected through a port into the combustion chamber and directing the fluid fueled fire into the combustion chamber through the port which is located midway of the length of the sidewall of the combustion chamber.

Abstract: Solid fuel supported on a grate within the combustion chamber of a furnace, is ignited by a liquid or gas fuel burner projecting its flame entirely within the same combustion chamber. A forced inflow of air is preheated by being conducted below and in surrounding relation to the combustion chamber and then passed in heat exchange relation to heat transfer ducts through which combustion products are conducted from the combustion chamber.