MULTIPLE ELECTRODE VACCUM ARC FURNACE AND METHOD OF REMELT PURIFICATION

摘要

1,207,546. Casting processes. UNITED AIRCRAFT CORP. 10 Dec., 1968 [11 Dec., 1967], No. 58515/68. Heading B3F. [Also in Division H5] A process for the vacuum arc purification of a metal comprises forming the metal to be purified into a plurality of consumable electrodes 9, uniformly spacing the electrodes in a furnace, maintaining a vacuum in the furnace, forming an electric arc at the surface of each electrode so as to melt the metal, and forming the molten metal into an annulus in the furnace, both the internal and external surfaces of the annulus being cooled. The electrodes may be in the form of ring segments (30), Fig. 3 (not shown), and are lowered by motors (11) as they are consumed. The current flowing through each electrode is monitored by inductive means (29), Fig. 1 (not shown), connected to a comparator (20) which causes the motors (11) to adjust the positions of the electrodes 9 so that the current flow through all the electrodes is substantially equal. Cooling water is supplied to a water jacket 3 via inlets 6 and 6SP1/SP and leaves via outlets 7 and 71