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 wood or multi-fuel stove comprises a primary combustion chamber, a flue duct extending from an upper part of the primary combustion chamber; a grate defining a lower boundary for the primary combustion chamber, the grate extending from the front towards the back of the stove interior and having a front edge juxtaposed with the front of the stove; a secondary combustion chamber located beneath the grate linked to the primary combustion chamber; an inlet path for supplying fresh air to the secondary combustion chamber, the inlet path by-passing the primary combustion chamber; and an outlet path for conveying combustion products from the secondary combustion chamber to the flue, the outlet channel by-passing the primary chamber; the stove being characterized in that: the primary combustion chamber (X) is defined at least on its rear side by an insulated member (12); the grate (1) has: (i) a rear edge off set from the insulated member to leave a gap (G); extending over all, or part of, the width of the grate (1

Abstract: A compact gas combustion furnace includes a substantially rectangular casing having an interior defined by a plurality of compartments. A draft inducer is mounted above the heat exchanger compartment to allow a multipass heat exchanger to be used while allowing the furnace to be fitted within a mobile home closet. A transition box couples the horizontally disposed inlet of the inducer and the vertically disposed outlet side of the heat exchangers. In a preferable arrangement, the furnace includes a burner assembly utilizing a plurality of burners, each having an arcuate shape in relation to a corresponding plurality of heat exchangers, and thereby occupying a minimum of space without loss of efficiency.

Abstract: A heating furnace is provided with a counterflow heat exchanger defining serpentine up flow fresh air passages and downflow combustion products passages. The exchanger is of sheet metal modular construction.

Abstract: A draft-assisting chamber is positioned between the combustion chamber and the flue pipe of a heating appliance so as to capture combustion gases in a quantity sufficient to initiate gas flow through the flue pipe. By use of the chamber, gas flow is initiated in the flue pipe during conditions that would otherwise delay such initialization.

Abstract: A burning method and apparatus, using solid type fuel, comprising a combustion chamber in combination with a heat-extractor labyrinth chamber through which an artificial draft is generated mechanically. The artificial draft can be generated by intake and exhaust fans and/or blowers operating at accurately controlled speeds.In a specific stove-type embodiment, the draft-flow within the combustion chamber is utilized by a reversal of its flow pattern for either conventional up-draft burning, or preferably, for down-draft burning, with the gases exiting through the heat extractor compartment at close to ambient temperature and a short horizontal flue into the atmosphere. In this embodiment, the intake fan also serves to distribute usable heat from the surfaces of the combination and heat extractor compartments.

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 sustained ignition secondary combustion apparatus in a housing of refractory insulating material includes a first level for conducting secondary air through a secondary air inlet and channel, and a second level for conducting smoke products. A partition separates the levels or zones. Openings are provided in the partition between the levels bounded by a high temperature porous or fiberlike material in the form of igniter tube elements. Secondary air and smoke products diffuse into the interstices of the porous or fiberlike material where contact and combustion maintains the igniter tubes at or above the ignition temperature. Ignition and secondary combustion of smoke products in the second level is therefore sustained and secondary air is preheated as it passes through the openings. A secondary combustion zone is defined in the region of the openings between the levels and continues down stream through the exhaust outlet.

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: This invention has to do with apparatus for burning solid fuels in successive stages whereby the fuel is completely converted to clean, hot, incombustible gases and to ashes, and, without admixture, transfers its heat to clean fresh air for distribution to areas to be heated.