A fire construction (10) comprising a firebox (12) defining a combustion chamber (14) in which fuel (not shown) can be burnt, a first air supply means (16) for delivering air into the combustion chamber (14) to support combustion of fuel therein, and a second air supply means (18) for supplying additional air to support combustion of fuel within the combustion chamber (14), the second air supply means (18) comprising a supply conduit (20) connecting the combustion chamber (14) with an air supply (22), the supply conduit (20) having a cross section (24) that increases as the supply conduit (20) opens into the combustion chamber (14).

Disclosed is a fireplace which includes a firebase, a primary combustion zone with a first air supply unit, a secondary combustion zone, and an exhaust flue. The fireplace place also includes a charcoal/reduction layer which forms between the primary combustion zone and the secondary combustion zone, the arrangement and construction being such that the gases and/or particulate matter produced from the pyrolysis and/or combustion of the biomass fuel in the primary combustion zone have to pass over, or through, the charcoal/reduction layer prior to entering the secondary combustion zone and/or the exhaust flue. The fireplace also includes a second air supply unit for introducing heated secondary air into, or adjacent to, the secondary combustion zone, the arrangement and construction being such that the secondary air passes through (or adjacent to the region of) the charcoal/reduction layer to thus heat the secondary air.

A single burn rate stove including a burn chamber configured to burn biomass therein and a door configured to receive primary combustion air and provide the received primary combustion air to the burn chamber. The door is at a front of the stove. The stove further includes a bottom configured to receive secondary combustion air, a plurality of secondary air tubes extending across a top of the burn chamber, and a secondary air manifold configured to conduct the secondary combustion air from the bottom to the plurality of secondary air tubes.

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 solid fuel burning cabinet circular heating appliance achieves improved emissions performance by providing a secondary air combustion path that preheats secondary combustion air. The firebox is selectively insulated such that areas of the firebox that do not preheat combustion air retain heat in the firebox while areas of the firebox that transfer heat into the combustion air transfer heat through the firebox into the incoming combustion air. The exhaust air path from the firebox to a chimney is also uninsulated to allow relatively quick heat transfer into a room in which the appliance is installed.

An apparatus and method for the combustion of solid fuel are provided. The apparatus includes a combustion chamber with a floor, a side opening, an airflow disk located above the side opening, and secondary air inlets located above the airflow disk. The apparatus and method can efficiently combust solid fuels with low emission of particulate matter and harmful gases, continuous feeding of fuel during combustion, and the production of a spiral flame.

A portable fireplace for burning combustible fuel includes an outer wall defining a lower portion and a tower portion, an inner wall separated from the outer wall by an air gap and defining a combustion chamber within the lower portion and a chimney within the tower portion. The portable fireplace also includes a fireplace aperture through the outer wall and inner wall, a mantel below the fireplace aperture and projecting outward from the outer wall, a number of inlet ventilation holes in the outer wall, and a number of outlet ventilation holes in the inner wall within the combustion chamber.

A clean combustion stove is described herein. The clean combustion stove may include a tapered heating chamber further including a primary combustion zone and a secondary combustion zone. The primary combustion zone, in a lower portion of the tapered heating chamber, may include a grate configured to support a fuel source and a first set of intake elements configured to intake air from outside of the tapered heating chamber, fueling primary combustion of the fuel source, which may produce smoke. The secondary combustion zone, in an upper portion of the tapered heating chamber, above the primary combustion zone, may include a second set of air intake elements connected to a circulation tube via one or more intake tubes. The second set of intake elements may be configured to intake air from outside of the tapered heating chamber, fueling secondary combustion of the fuel source, which may eliminate the smoke.

Aspects of the present invention provide biomass combustion stove with an exhaust gas mixer. The exhaust gas mixer is positioned in the exhaust gas outlet of the stove. That is the exhaust gas mixer is positioned within the path of exhaust gases exiting the stove housing at the point where the exhaust gases exit the housing, above a baffle of the stove. The exhaust gas mixer may be a cone, a pair of opposing cones, a sphere, turbine, propeller, partial helical, or fan configured to promote mixing and/or turbulence of the exhaust gases as they exit the housing. In one embodiment, the stove provides some room air to the exhaust gas outlet and flue above the baffle to cool the exhaust gases as they exit the housing via the exhaust gas outlet of the stove.

Aspects of the present invention provide biomass combustion stove with an exhaust gas mixer. The exhaust gas mixer is positioned in the exhaust gas outlet of the stove. That is the exhaust gas mixer is positioned within the path of exhaust gases exiting the stove housing at the point where the exhaust gases exit the housing, above a baffle of the stove. The exhaust gas mixer may be a cone, a pair of opposing cones, a sphere, turbine, propeller, partial helical, or fan configured to promote mixing and/or turbulence of the exhaust gases as they exit the housing. In one embodiment, the stove provides some room air to the exhaust gas outlet and flue above the baffle to cool the exhaust gases as they exit the housing via the exhaust gas outlet of the stove.