PREVENTION OF EROSION OF PIG STORAGE TYPE TAPPING SPOUT

PURPOSE:To suppress the erosion of the metal line of a tapping spout by making as small as possible the layer thickness of blast furnace slag covering the front layer of pig iron during the storage of the pig iron. CONSTITUTION:A freely openable and closable gate 14 is provided to the molten iron spout nose 13 of the tapping spout 10 and the gate 14 is kept pen during tapping. The gate 14 is lowered to shut off temporarily the molten iron flow at the same instant when the tapping port of the blase furnace is closed. The level of the pig iron 4 in the spout 10 is therefore made the same as the level during tapping and the residual blast furnace slag 5 is mostly discharged from a molten slag port 12. The gate 14 is raised to discharge the residual pig iron from the nose 13 so as to store the pig iron when no more outflow of the slag from the port 12 is admitted. The volumetric ratio of the blast furnace slag 5 and the pig iron 4 during the storage is thus made to about 0.25:1 from 1:1 during the non-operation and the degree of the erosion of the metal line is decreased to about 1/3 the degree of the erosion of the conventional tapping spout.