PURPOSE: To clean diffuser pipes one by one by appropriately closing a shutoff valve and without shutdown by providing plural waste gas diffuser pipes furnished with a shutoff valve at the bottom of a furnace.
CONSTITUTION: Plural diffuser pipes 6 are horizontally arranged in parallel at the bottom of a prereducing furnace main body 5. Diffuser holes 7 are provided to each diffuser pipe 6 at appropriate intercals. One end of the pipe 6 is connected to a header 8 outside the furnace, and a shutoff valve 9 is furnished on one end side of the pipe 6 positioned outside the furnace. The waste gas from a smelting and reducing furnace is supplied to each pipe 6 from the header 8 and blown off into the furnace 5 from the holes 7 to form the fluidized bed 11 of ore. When dust deposits in the pipe 7 to some extent, the shutoff valve 9 of any pipe 7 is closed, and the supply of waste gas to the pipe 7 is stopped. A lid 10 is opened, and the inside of the pipe 7 is cleaned. Consequently, waste gas is stably blown into the fluidized bed 11.
ARIYAMA TATSURO
TSUBOI HARUTO
ISOZAKI SHINICHI
KITANO YOSHIYUKI
ARAKAWA SAKAE
