Combustion chamber for charcoal stove

A biomass stove comprising;

• an upper section defining an outer wall and an inner wall separated by at least one cavity, the inner wall defining an upper combustion chamber,
• a lower rim positioned at the bottom of the first inner wall and bottom of the outer wall, wherein
• a funnel structure positioned at or near the bottom of the inner wall, wherein the bottom of the funnel structure defines a cross-sectional dimension that is larger than a cross-sectional dimension defined by the top of the funnel structure;
• an orifice ring positioned within and in contact with the inner wall of the upper combustion chamber, wherein the orifice ring has an inner diameter and an outer diameter, the inner diameter being smaller than the diameter of the upper combustion chamber;
• a lower section defining an outer wall and an inner wall separated by at least one cavity, the inner wall defining a lower combustion chamber;
• an upper rim positioned at the top of the first inner wall and top of the outer wall, wherein
• the upper and lower sections are separably engaged at said respective upper rim and lower rim,
• the lower combustion chamber for receiving fuel, and
• a plurality of air flow apertures, wherein the apertures are substantially shielded from the direct line of site of a fuel bed positioned on a grate;
• and
• the upper combustion chamber further defines a funnel structure in direct line of site of the fuel bed.