METHOD FOR CONTROLLING BLOWING OF GAS AT ITS END PERIOD IN WEAKLY STIRRED BOTTOM-BLOWING CONVERTER

摘要

PURPOSE:To control a blowing end period gas with high accuracy by dynamically adjusting the specifications of blowing for the blowing end period gas in a weakly stirred bottom-blown converter in accordance with the online measured value of the furnace conditions such as the concn. of C in the molten steel in the end period of blowing and the temp. of the molten steel. CONSTITUTION:The control of the blowing end period gas is executed in accordance with the specifications for blowing the blowing end period gas determined prior to blowing or in the first half of blowing by a static control calculation, etc., in the weakly stirred bottom-blown converter. The furnace conditions such as concn. of C in the molten steel and the temp. of the molten steel are measured online at the end period of blowing in the above-mentioned control method. This measurement is executed by a sub-lance or device for exhaust gas analysis, etc. The above-mentioned specifications are dynamically adjusted in accordance with the result of the measurement. The blowing end period gas is thereby exactly controlled to stabilize T-Fe in blowing-out slag, by which the yield and the predictability of the concn. of C are improved and the operations are stabilized.