A combustion tube assembly of a water heater includes a combustion tube having an open end, a closed end, and an outflow opening between the open end and the closed end. A cavity of the combustion tube provides a chamber for a combustion of a water heater fuel, where the outflow opening provides an outlet for an exhaust gas resulting from the combustion of the water heater fuel to exit the combustion tube. The combustion tube assembly further includes a spring positioned in the cavity of the combustion tube at the closed end of the combustion tube.

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 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 solid fuel burning device has at least one burn chamber wall, a burn chamber base, and an interior burn chamber. The burn chamber base is capable of supporting a combustible solid fuel thereon. At least one of the burn chamber walls is radially offset with respect to another of the burn chamber walls. At least two longitudinally extending air inlets are formed in the space between a first longitudinal edge of at least one of the burn chamber walls and a second longitudinal edge of another burn chamber wall. Each of the longitudinally extending air inlets tangentially directs an entry of air into the interior burn chamber to induce an interior swirl of air in the interior burn chamber. The interior swirl of air in the interior burn chamber causes a flame of a combusting solid fuel to swirl in the interior burn chamber.

A solid fuel burning device has at least one burn chamber wall, a burn chamber base, and an interior burn chamber. The burn chamber base is capable of supporting a combustible solid fuel thereon. At least one of the burn chamber walls is radially offset with respect to another of the burn chamber walls. At least two longitudinally extending air inlets are formed in the space between a first longitudinal edge of at least one of the burn chamber walls and a second longitudinal edge of another burn chamber wall. Each of the longitudinally extending air inlets tangentially directs an entry of air into the interior burn chamber to induce an interior swirl of air in the interior burn chamber. The interior swirl of air in the interior burn chamber causes a flame of a combusting solid fuel to swirl in the interior burn chamber.

The invention is a novel Top-Lit-Updraft cook stove with internal forced primary and secondary air, designed to burn biomass. The cook stove is specifically designed to cleanly burn biomass. The stoves design innovations include a cylinder-within-cylinder design to provide heated, forced secondary to the burner area right below the burner. The burner design addresses limitations in previous cookstove burner design by implementing a bluff body design to direct syngas to the secondary air jets, improving mixing and combustion of volatile gases.

The invention is a novel Top-Lit-Updraft cook stove with internal forced primary and secondary air, designed to burn biomass. The cook stove is specifically designed to cleanly burn biomass. The stoves design innovations include a cylinder-within-cylinder design to provide heated, forced secondary to the burner area right below the burner. The burner design addresses limitations in previous cookstove burner design by implementing a bluff body design to direct syngas to the secondary air jets, improving mixing and combustion of volatile gases.

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.

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.

A burning stove includes a stove body, a front seat, a door, a rear seat, a top cover, and a baffle. The baffle divides the stove body into an air inlet chamber and a combustion chamber. The door is provided with first air inlet holes and second air inlet holes. The baffle is provided with first air holes. The baffle is provided with an air guide port and an air guide face. First partial air flows backward in the air inlet chamber, flows through the air guide port and the air guide face, and flows upward into the combustion chamber, and second partial air in the air inlet chamber flows through the first air holes into the combustion chamber. The first partial air and the second partial air form a vortex air flow in the combustion chamber.