PURPOSE: To perform uniform dispersion of reduction gas by a method wherein a solid gas separator and a downcommer are arranged in juxtaposition to a fluidized bed layer reduction furnace having a window box and the fluidized bed furnace is coupled to the window box through a gas introduction pipe in which an orifice is located.
CONSTITUTION: Reduction gas 2 is introduced as main fluidized gas in a fluidized bed reduction furnace 1, charged with an iron ore, from a window box 4 through a plurality of gas introduction pipes 3. A reduction iron ore on which fluidized reduction is applied is separated at the upper part of the furnace away from gas by means of a solid gas separator 5. The reduction ore is fed to the lower part of the furnace through a downcommer 6 as it is circulated and a part of the reduction ore is taken out through a product reduction ore discharge port 7. Through the gas introduction pipe 3 has a plurality of introduction nozzles 3-1-3-3 supported by a support late 12, in this case, an orifice 11 having a pressure loss of not less than 20% is arranged to the nozzles 3-1-3-3. This constitution causes the increase of ventilation resistance during the passage of it through a pipe, and uniform dispersion of reduction gas to the nozzles 3-1-3-3.
TAKAMOTO YASUSHI
EGASHIRA TATSUHIKO