| 摘要 |
PURPOSE:To surely converge molten steel level to a target level by using a solenoid valve for controlling the opening amount of a sliding nozzle and changing the next opening amount in an optimum manner from the fluctuation in the molten steel level with respect to the nozzle opening amount. CONSTITUTION:In the initial pouring into a mold 6, a 3-position solenoid valve 14 is manually controlled to drive an actuator 11, by which the opening amount of a sliding nozzle 5 is controlled. When the steel level goes constant, the manual operation is changed over to automatic operation and the opening amount of the nozzle 5 is detected with an opening amount detector 12 and is sent to a control circuit 15 which determines coefficients successively from the change rate of the molten steel level in a predetermined time with respect to the change rate of the nozzle opening amount. From these coefficients, the next nozzle opening amount is determined and the molten steel level is so controlled as to attain a target value. Further, whether the change rate of the nozzle opening is within a permissible range or not is checked. Thereby, the molten steel level in the mold 6 is surely settled at a prescribed level. |
