| 摘要 |
PURPOSE:To prevent closing of immersion nozzles that arises from low temp. charging of molten metal by forming an electrically closed circuit communicating with each molten metal in the nozzles, in an intermediate vessel and in a casting mold, forming a mutual induction coupling circuit using the closed circuits as its secondary circuit and generating alternating current in the secondary circuit. CONSTITUTION:Immersion nozzles 6, 7 are juxtaposed to a tundish 1, and a magnetic core 9 constituting a transformer part 8 is intersected with the outside circumference of one nozzle 7. A primary winding 10 connecting to an electric power source is wound in the end part of the core 9. An electrically closed loop is created by the molten metal 3 in the tundish 1, the nozzles 6, 7 and a casting mold 4, and the loop functions as a secondary conductor of the transformer 8. When electric current is flowed to the primary winding 10, routes (a), (b), (c), (d) form a secondary winding, through which the induced current flows, thereby constituting a transformer. Since the sectional area of the routes (b), (d) is smallest, the current density in this part is largest, and the nozzles 6, 7 are heated thoroughly by Joule heat, whereby the closing of the nozzles is prevented. |
