| 摘要 |
<p>PROBLEM TO BE SOLVED: To set electrodes to a proper position in melting slag, and prevent abrasion of the electrodes and reduction in durability of a melting tank by detecting a sudden change in an electric current or voltage when the tip of the electrode makes contact with a molten metallic layer by lowering the electrode, and raising this electrode by a preset height. SOLUTION: Among plural electrodes, one electrode 2B is rested by being soaked in the vicinity of a surface of melting slag 4. The other electrode 2A is lowered from this condition, and is soaked in a molten slug 4, and is lowered in the molten slug 4. An electric current is carried between the electrodes 2A and 2B through the molten slug 4 from when the electrode 2A contacts with an upper surface of the molten slug 4. When the tip of the electrode 2A reaches an upper surface 3A of melting metal 3, an electric current flowing in the electrodes 2A and 2B or voltage suddenly changes. An electric current or voltage detecting means detects this moment, and outputs a detecting signal. By this signal, the electrode 2A is stopped by being raised by a preset height h1 from a position contacting with the upper surface 3A of the molten metal 3. Next, in the electrode 2B, a position is set similarly to a case of the electrode 2A.</p> |
