| 摘要 |
PURPOSE:To control strictly the liquid level of the molten steel in a casting mold and to perform continuous casting with high quality, by providing a controller for emergency use separately from a PID controller which controls automatically the liquid level of the molten steel in the mold and suppressing the excessive fluctuation in the liquid level. CONSTITUTION:When a liquid level detector 8 detects the liquid level of the molten steel in a casting mold 1, said detector inputs the signal thereof to a PID controller 10 via a filter 9. The controller 10 calculates a control signal from the deviation between the set value of the liquid level of the molten steel and the detection signal and feeds said signal to a servocontrol amplifier 11. Then a servocontrol valve 12 is driven to actuate a hydraulic cylinder 12, thereby controlling the opening of a flow rate control valve 6. A controller 14 for emergency use is provided in parallel with the controller 10. The controller 14 adds the control signal output for emergency to the control signal of the controller 10 when the liquid level of the molten steel exceeds a prescribed fluctuating width and the valve 6 is controlled by said signal, whereby the excessive fluctuation thereof is suppressed. |
