GB190629019A - Improvements in or relating to Electric Induction Furnaces. - Google Patents

Abstract

29,019. Gr÷ndal Kjellin Co., and HõrdÚn, J. Dec. 19. Transformers. - An induction furnace is adapted to be worked by polyphase alternating currents by the use of one or more transformers, to convert the currents to single phase. The transformers may be combined with or detached from the furnace. Fig. 1 shows an arrangement of two separate transformers with primaries connected to the mains C<2>, D<2> of a two-phase system. The secondaries B3, B' are connected in series so that the currents in them are in the same direction, and are in series with the primary B<5> of a furnace. The transformers may be combined together, and may be combined with the furnace as' shown in Fig. 3. Here the transformer windings are arranged on the outer members B<1>, B<2> of the furnace, a winding B<x> on the central member B being in series with the secondaries B<3>, B<4>, if desired, to diminish magnetic leakage due to the induced currents in the bath A. Fig. 4 shows an application to a three-phase system, in which, for example, the Scott system of transformation to two phase is adopted. The secondary transformer coils B<3>, B<4> are connected to a winding B<5> on an outside member of the furnace, the two-phase currents being converted into single phase in the furnace as above described.