Regenerative furnace

An open-hearth furnace using producer gas as a fuel, but so arranged that the gas is conducted to the hearth area through a passageway filled with red-hot bricks stacked to form an open checkerwork. As the hot gas enters the furnace, it is mingled, in proper proportions, with air similarly heated; so that complete combustion is produced. The escaping hot gases are conducted through a second passageway filled with bricks, which absorb much of the waste heat. The two passageways are used alternately to heat the producer gas as it is fed into the furnace.