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AssigneeSAPHYMO-STEL-Ste. d'Applications de la Physique Moderne et de l'Electronique
InventorJean Reboux
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A direct induction furnace or device for melting a charge held in a cold sheath or shroud with electromagnetic confinement of the conducting portions of the charge. The cold shroud comprises a cylindrical sidewall, which is composed of a plurality of juxtaposed segments in the shape of a hairpin inductor, each formed by two parallel tubular conductors, which are insulated from each other along their entire interface with the exception of a transverse section which electrically and hydraulically connects one end of one of the sections to the adjacent end of the other section. The other ends of these two conductors are, respectively, electrically and hydraulically connected by tubular conductors to two tubular ring-shaped collectors which are respectively electrically connected to two output terminals of a second generator of alternating current of medium or high frequency, in such a way that the alternating currents which thus flow through the cluster of tubular conductors making up the cold shroud, flow alternately in opposite directions so as to generate forces of repulsion at the periphery of the conducting portion of the charge, which is thus kept away from the shroud sidewall, thereby ensuring a supplementary confinement thereof.
Device for direct induction melting of a charge, including:
A method of using for direct induction melting of a charge contained in a cold shroud having a cylindrical sidewall made up from an assembly of conducting, vertically oriented tubular sections cooled by a flow of cooling fluid and surrounded by a heating inductor of solenoid-shape, said tubular sections being insulated from each other, including the adding to a metallic charge before its introduction into the shroud, of a substance which is insulating when cold and which has its temperature of inductibility and melting point close to each other and lower than the melting point of the metal forming the charge, said insulating substance forming a slag which is expelled from the melt towards its periphery for providing, when cooled by the contact with the shroud sidewall, an electrically and thermally insulating layer, wherein the improvement comprises the passing of alternately oppositely directed alternating currents along said tubular sections forming said shroud, by electrically interconnecting them at their respective adjacent ends, two by two, to obtain hairpin-shaped inductors, and by connecting said hairpin-shaped inductors thus obtained to a generator, whereby to generate an eletromagnetic field of supplementary confinement acting on the conducting portions of the charge and to increase said insulating layer thickness.
Dependencies are inferred from the claim text.