| 摘要 |
PURPOSE:To reduce operational cost caused by reducing number of iron tapping by controlling hot blast blowing from a tuyere above iron tapping hole at the end period of the iron tapping at the time of tapping the molten iron from the iron tapping hole in a blast furnace to reduce remaining iron quantity in a hearth part and increase the quantity of iron tapping per one time. CONSTITUTION:When the molten metal stores in the hearth part 4 in the blast furnace 1, the iron tapping hole 2 is opened and molten iron 9 and molten slag 10 are extruded through the iron tapping trough 8. As the surfaces of the molten iron 9 and the molten slag 10 are inclined caused by blowing of high pressure hot blast from the tuyere 3 above the iron tapping hole 2 in the furnace, at the time of starting spout of furnace gas from the iron tapping hole 2 at the end period of the iron tapping operation, opening degree of a blast control valve 7 arranged to the blast blanching pipe 6 for hot blast connected with the tuyere 3 is made to <=40%. By this method, the pressure of the hot blast from the tuyere 3 is lowered, caused to inclined angles of the surfaces of the molten iron 9 and the molten slag 10 are reduced, and the surface of the remaining molten iron 9 is raised at the position of the iron tapping hole 2 and the iron tapping can be continued. Thus, the remaining quantity of the molten iron in the furnace is made to little and by increasing the quantity of iron tapping per one time, the number of the iron tapping operation is reduced, and material consumption for the iron tapping operation is reduced. |
