| 摘要 |
PURPOSE:To control the flow rate of waste gas easily and highly efficiently with high accuracy by obtaining the flow rate of the gas produced in a converter by subtracting an estimated suction flow rate of the furnace port from the waste gas flow rate of the current point and adding a suitable preset suction flow rate of the furnace port. CONSTITUTION:At the start of blowing, first the reference coefficient of pressure loss at skirt height is determined with the waste gas flow rate from a waste gas flowmeter 3, and the signal of the furnace port hood pressure from a pressure gate 4, by an arithmetic device 7. Thence, ignition is made and the information on the flow rate from the flowmeter 3, the analysis value from an analyzer 5, the hood pressure from the gage 4 and skirt height is accumulated in the device 7 at every fixed period. After the ignition, the correction coefficient for the delay time of the analyzer 5 is calculated, by which the suction flow rate of the furnace port is determined and the waste gas flow rate is calculated. The waste gas flow rate is applied as a set value to a PID. In the PID, operations are made, and a manipulated variable signal is applied to a damper DC6 for controlling flow rate, whereby the waste gas flow rate is controlled. Thereafter, this is repeated at every fixed period. |
