GB1515707A - Apparatus and method for supplying electric power to an electric glass melting furnace - Google Patents

Abstract

1515707 Supply circuits for furnaces OWENSCORNING FIBERGLAS CORP 3 June 1975 [3 June 1974 24 Feb 1975 21 March 1975] 24004/75 Heading H2H Apparatus for heating molten glass by the Joule effect comprises a furnace 11 for containing glass constituents, at least two groups of electrodes 21-26 within the chamber, the electrodes of one group being coupled across one source of alternating voltage and the electrodes of the other group being coupled across another source of alternating voltage, and switching means 52-54 operable to couple the sources such that the sources are connected in series and in an additive sense between an electrode in one group and an electrode in the other group. As shown, three pairs of electrodes 21-26 are provided in the furnace, each pair of electrodes being connected to an A.C. source in the form of a respective transformer 28, 31, 33 connected to a single-phase source 27. The region of the furnace between each pair of electrodes is heated by the power supplied via a respective controller 29, 32, 34 in the form of a saturable reactor or inverse-parallel connected thyristors. In order to increase the heating effect in the region between pairs of electrodes 21, 22, and 23, 24, for example, the switch 52 is closed to connect the sources 28, 31 in series across the path between electrodes 21, 24. The heating is controlled by a controller 55 in the form of inverse-parallel connected thyristors. Similarly, closure of the switch 53 or 54 increases the heating in the path between electrodes 23, 26 or 22, 25. In a modification, the transformers are connected to a three-phase supply.