Patent ID: 8034283

Claim:
A rotary hearth furnace comprising: an outer wall; an inner wall disposed at the inner side of the outer wall; a ceiling covering a space between the outer wall and the inner wall from above; a rotary hearth disposed between the outer wall and the inner wall; a compartment-defining portion provided on part of the ceiling along the rotation direction of the rotary hearth; an exhaust duct connected to the compartment-defining portion, wherein the ceiling in the compartment-defining portion has a lower surface lying higher than the lower surface of the ceiling other than in the compartment-defining portion, and defines a compartment therein for allowing exhaust gas generated in the rotary hearth furnace to stay until the exhaust gas is introduced into the exhaust duct, wherein the compartment has a sectional area, in a section transverse to the direction of flow of the exhaust gas therein, greater than the sectional area of the exhaust duct in a section transverse to the direction of flow of the exhaust gas therein, and wherein the exhaust duct is connected to the compartment-defining portion so as to communicate with the compartment; and a plurality of oxygen-containing gas injection nozzles provided to the compartment-defining portion at a plurality of positions around the compartment, through which an oxygen-containing gas may be fed into the compartment.