METHOD FOR PLUGGING/OPENING MOLTEN METAL DISCHARGE HOLE AT FURNACE BOTTOM AND DEVICE FOR USING TO THEM

摘要

PURPOSE:To surely, safely and rapidly plug a discharge hole for molten metal at furnace bottom by packing heat resistant powdery and granular material conveyed with gas into the discharge hole for molten metal through an injecting nozzle inserted into the discharge hole for molten metal arranged at the bottom part in a refining furnace, etc. CONSTITUTION:The steel tapping hole 2 at the bottom part in a converter, etc., is plugged with a cover 8 driven to open/close through a link 10. The injecting nozzle 11 penetrating this cover 8 is inserted into the steel tapping hole 2 and the heat resistant powdery and granular material 5 of silica sand, etc., conveyed with gas is packed into the above steel tapping hole 2 through the injecting nozzle 11, and by this method, the steel tapping hole 2 is surely plugged. Successively, refining is executed in the above furnace and during refining, cooling gas of N2, CO2, Ar, LNG, etc., is allowed to flow into the injecting nozzle 11 beforehand made to project into the furnace to prevent the clogging and erosion with the molten metal. After completing the refining and before the prescribed time of steel tapping, O2 gas is supplied from the injecting nozzle 11 to heat and break the sintered packing layer near the nozzle 11. Successively, the above cover 8 is opened and the steel tapping hole 2 is safely and surely opened.