CONNECTION FOR DIRECT HEATING OF IONIC MELT ESPECIALLY OF GLASS BY ALTERNATING CURRENT PASSAGE WITH LOWER FREQUENCY THAN 50 HZ

摘要

A circuit for performing a method melting vitreous materials in an electric furnace wherein the electrodes are supplied with an alternating current of optimal frequency lower than 60 or 50 Hz, respectively, the corrosion of electrodes being minimized. The circuit comprises a cycloconverter which changes a three-phase current supply into a single-phase current with a simultaneous changing of the input mains frequency into an optimal output frequency. The circuit also comprises a device for measuring and/or controlling the direct current component of the low frequency feeding alternating current, in order to stabilize the favorable anticorrosion effect of the low optimal frequency. Further, it comprises a device for the control of the power input of the cycloconverter with respect to the melting temperature in the furnace.