PURPOSE: To enable high accurate control of C concn. in molten steel at end point of blowing by continuously catching the C concn. in the molten steel from the C concn. measured value in the molten steel by sapling during refining and after that, from the continuous measured value of C concn. in the exhaust gas of a converter.
CONSTITUTION: While stirring the molten iron 2 in the converter 1 by N2 gas blowing through a plug 4, O2 gas is blown into the molten iron 2 from a lance 3 and refined to produce the molten steel. Since the refining starts, after passing the prescribed time, sampling of the molten steel is executed with a sub-lance and C concn. in the molten steel is measured, to calculate the C content (C0) in the molten steel. Further, after this sampling, CO and CO2 concn. in the exhaust gas are measured with an analyzer 6 and the integrating quantity of C in the exhaust gas is continuously found from these concns. and flowing quantity of the exhaust gas measured with a flow meter 7. By this method, C content in the molten steel at some timing after sampling can be found by subtracting the C integrating quantity in the exhaust gas at this timing from the C content C0 in the molten steel and the purpose can be obtd.
FUKUMI JUNICHI
KOMAYA MASANORI
YAMASE OSAMU
