| 摘要 |
PURPOSE:To detect exactly and safely the position of a molten metal surface by subtracting the prescribed distance from the immersion depth in the stage when the buoyancy difference of the two characteristic straight line between the buoyancy determined by the specific gravity of slag and molten metal and the immersion depth attains the prescribed value while a heat resistant float is gradually immersed from a slag surface toward the molten metal. CONSTITUTION:The heat resistant float 16 is lowered from the slag surface 11 toward the molten metal 9 and while the float is immersed into the molten metal, the immersion depth (position information) Ln is detected by a rotary encoder 19 and the buoyancy Bn is detected by a load cell 17. The values of Ln and Bn are inputted to a processing unit 20. The unit 20 calculates the Bn-Ln characteristic straight line (the 1st buoyancy reference straight line) determined by the specific gravity of the slag until the float 16 arrives at the molten metal surface 14 from the point P1 where the float arrives at the slag surface 11 and the Bn-Ln characteristic straight line (the 2nd buoyancy reference straight line) during the immersion of the float into the molten metal from the values of Ln and Bn inputted sccesssively to said unit. The processing unit determines the intersected point P2 of both straight lines by subtracting the reference distance calculated according to the 1st characteristic straight line from the immersion depth Ln when the difference in the buoyancy Bn between the two straight lines attains the prescribed value. THe molten metal surface 14 is thus detected with high accuracy. |
