Heating molten metal

摘要

Apparatus for applying heat to a reservoir (27) of molten metal, comprising a plasma torch (48) and a metal contact electrode (52) to complete an electrical circuit with the torch (48) via the molten metal in the reservoir (27). The plasma torch (48) and the metal contact electrode (52) are both mounted on a stand (51) for up and down movements as a unit so as that the plasma torch (48) is moveable downwardly into proximity with the surface of the reservoir of molten metal and the metal contact electrode is simultaneously insertable into the molten metal and withdrawable therefrom. The metal contact electrode (52) is formed with an interior passage (63) for flow of gas therethrough into the molten metal and there is provided a gas pressure detector (65) to detect a change in gas pressure consequent on breakage of the metal contact electrode (52).