A furnace for combusting wood comprises a firebox floor in a primary burn chamber of the furnace, where the wood is received for generating a gas therefrom, that is defined by a thermally conductive body of refractory material. The body of refractory material defines an upper support surface arranged to support the wood above or over the same. The body of refractory material also defines, beneath the upper support surface, a duct as part of a secondary burn chamber of the furnace which is arranged (i) to be communicated with the primary burn chamber of the furnace to receive the gas generated by heating of the wood therein and carrying combustible products, and (ii) to convey the gas in a manner supporting combustion of the combustible products carried thereby.

A heating device, preferably for the combustion of biomass, in particular of pellets of biomass, in one aspect, includes a burner part and a heating part. The burner part includes a combustion chamber; a double-walled, internally hollow combustion-chamber wall, which has an upper opening leading above the combustion zone into the combustion chamber; a flue-gas duct which leads the flue gas downwards along the combustion chamber, wherein the flue-gas duct is followed by a heat-exchanger area including initially, a flat-tube flue-gas heat exchanger, then, a tertiary-air heat exchanger; a flue-gas ventilation stack, a radiant-heat exchanger located above the combustion chamber, a flue-gas flap at the upper end of the flue-gas duct, which, when open, connects the flue-gas duct to the stack. A flat-tube flue-gas heat exchanger of the heating part forms a heat-exchanger circuit with an exhaust-air heat exchanger with the same heat-transfer medium as the flat-tube flue-gas heat exchanger.

A burner for burning fuels and modular heat utilizing appliances therefor. The burner includes a fuel holder, an outer wall surrounding the fuel holder and defining a combustion chamber, and optionally, a second wall surrounding the outer wall. Air is inducted from an inlet which may be an ash pan pivotally coupled to the outer wall at the bottom to open the combustion chamber. Supplementary combustion air is conducted to just above the fuel holder by the outer wall. Additional supplementary combustion air is conducted to just above the fuel holder by the second wall. The burner may include a pivotally mounted cooking grate and a pivotally mounted solid cover for closing the combustion chamber, and supporting legs. Modules individually yet replaceably attachable to the burner include a closed or open cooker, a smoker, a space heater, and a pyrolyzer.

A furnace for combusting wood comprises a firebox floor in a primary burn chamber of the furnace, where the wood is received for generating a gas therefrom, that is defined by a thermally conductive body of refractory material. The body of refractory material defines an upper support surface arranged to support the wood above or over the same. The body of refractory material also defines, beneath the upper support surface, a duct as part of a secondary burn chamber of the furnace which is arranged (i) to be communicated with the primary burn chamber of the furnace to receive the gas generated by heating of the wood therein and carrying combustible products, and (ii) to convey the gas in a manner supporting combustion of the combustible products carried thereby.

The present disclosure relates to a non-electric, multifunctional, configurable pellet-burning system for domestic and industrial use, which has a removable burner and an inclined hot gas outlet duct that connects said burner of the system with a heat accumulator tank that operates as a second combustion chamber and as a particle filter.

A cooking system having a pellet fueled cooking chamber, a fire chamber held in a fixed relationship with respect to the cooking chamber, and a user adjustable port that selectively allows fluid communication from the fire chamber to the cooking chamber.

A combustion assembly housing contains primary and secondary combustion chambers and an ash receptacle. The primary combustion chamber has primary and exhaust grates. Fuel pellets fall in downward onto the primary grate; intake air flows in upward through the primary grate; exhaust gas flows out rearward through the exhaust grate. The primary grate supports unburned fuel pellets and permits partially burned pellets to fall through. Multiple vertical passages through the primary grate are each deeper than they are wide. The secondary combustion chamber has a secondary grate. Partially burned pellets fall in downward onto the secondary grate; intake air flows in rearward, through the secondary grate, and out upward into the primary combustion chamber. The secondary grate supports partially burned pellets and permits ash to fall through downward into the ash receptacle. Intake air flows rearward into the ash receptacle and upward into the secondary combustion chamber.

A biomass pellet combustion system includes a primary burn chamber, a coal burn chamber, and a gas burn chamber. The primary burn chamber is configured to receive pellets from a drop tube of the biomass pellet combustion system. The coal burn chamber is configured to receive coals from the primary burn chamber. The gas burn chamber is configured to receive combustible gases from both the primary burn chamber and the coal burn chamber, wherein a secondary combustion process converts secondary combustion air and the combustible gases into exhaust gases in the gas burn chamber.

A combi stove (1) is arranged for combusting both logs and granular material. The combi stove (1) has a common combustion chamber (2) arranged so that both the logs and the granular material may be combusted in the common combustion chamber (2). The combi stove (1) further has an ash collector (3) arranged under the combustion chamber (2) and a front aperture (4) through which logs may be placed in the combustion chamber (2). Also the combi stove (1) includes a granular material combustion area (5) arranged in the combustion chamber (2), wherein the granular material combustion area (5) has a bottom combustion surface (6) including bottom airflow apertures (7) arranged to enable an airflow to the granular material during a combustion of the granular material in the granular material combustion area (5). The granular material combustion area (5) is at least partly surrounded by a granular material area sidewall (8) having sidewall airflow apertures (9) arranged to enable an airflow to flue gasses generated during a combustion of the granular material in the granular material combustion area (5). At least a part of the granular material area sidewall (8) is releasable from the granular material combustion area (5). Furthermore, a use of a combi stove (1).

A solid fuel combustion device includes: a fuel supply device including a firewood feed pipe or another fuel supplier; a primary combustion chamber coupled to the fuel supply device; a secondary combustion chamber including a wall formed of a fireproof material and having a structure in which a space is formed at a side of the combustion gas outlet of the primary combustion chamber to induce primary combustion gas to be secondarily expanded and combusted; and an air supply system including at least one air supply device in an entire combustion path formed in the primary combustion chamber and the secondary combustion chamber.