| 摘要 |
PURPOSE:To prevent the generation of a cold shut on the surface of an ingot by providing a control system having a high response speed so that level fluctuations can be decreased particularly with a high frequency component. CONSTITUTION:A pressure box 14 is attached to a nozzle 15. The position of a molten steel level 8 is detected by a level sensor 12 and the level signal is fed to a signal processing system 13. The high frequency component of which the fluctuation period of the level fluctuation is below, for example, 2 seconds is fed to the control system 9 and the low frequency component of which the fluctuation period is above, for example, 2 seconds is fed to a stopper position control system 11 in the signal processing system 13. The pressure of the pressure box 14 is controlled at <=1 second time constant by the control system 9, by which the fluctuation width of the molten steel level 8 is suppressed within the extremely small range. |
