| 摘要 |
1,243,162. Electro-slag refining supply systems. BOHLER & CO. A.G. GEB. 3 Feb., 1970 [3 Feb., 1969], No. 5224/70. Heading H2H. The electrodes 9, 9<SP>1</SP> of an electro-slag remelting apparatus are fed from a three phase A.C. supply RST by way of two parallel circuits comprising ON-OFF switches 2, 2<SP>1</SP>, step-down transformers 3, 31 and thyristor devices 6,6<SP>1</SP>, each of the thyristor devices being arranged to provide a single phase alternating voltage output having a square waveform, the outputs being connected one to each of the electrodes 9, 9<SP>1</SP> and commonly to the mould 14 of the remelting apparatus. The output voltages U 1 , U 2 of the thyristor devices 6, 6<SP>1</SP> are adjustably controllable by means of a device 7 infinitely between an in-phase relationship and an antiphase relationship. When the voltages U 1 , U 2 are in phase the voltage U E between the electrodes 9, 9<SP>1</SP> is zero, the current J E between the electrodes is zero and the current J B between the electrodes and the base 14 is a maximum. Conversely when the voltages U 1 , U 2 are antiphase, the voltage U E between the electrodes is a maximum, the current J E between the electrodes is a maximum and the current between the electrodes and the base is zero. Values of voltage and current between these figures are obtained by phase shifting the voltage U 1 relatively to the voltage U 2 . The electrodes may each comprise a group of electrodes in parallel and, if desired, more than two groups of electrodes may be provided which are energized in a sequence so as to produce a rotary field which causes a stirring effect in the slag and liquid metal. Furthermore the energization may be reversed to reverse the stirring effect. |
