JPS5633440A - Slag depth measuring method - Google Patents

Abstract

PURPOSE:To correctly measure the depth of slag with superior reproducibility by arranging differently protruded two electrodes in parallel and moving them from an upper portion of the slag to molten metal through the slag to detect potential differences at the slag surface and the slag bath bottom. CONSTITUTION:Electrode 16a is protruded to a position lower than that of electrode 16b. At the time of starting measurement, both the electrodes are at a stop over slag 14, and simultaneously with measurement they are lowered with motor 32. Potentiometer 30 outputs a voltage proportional to the lowering distance to operation unit 28. When electrode 16a reaches the surface of slag bath 14, an electric current flows through the passage of 22-20-16a-14-10, and the potential of electrode 16a is lowered by a voltage drop due to resistance 20 to generate a potential difference between both the electrodes. Amplifier 24 amplifies the difference and outputs the value, and at this time, unit 28 stores output voltage V1 of potentiometer 30. When electrode 16a reaces molten metal surface L2 and electrode 16b reaches slag bath surface L1, a potential difference change occurs between both the electrodes. Unit 28 stores this output voltage V2, calculates V2-V1, and outputs the value as a slag bath depth signal.