GB959367A - High vacuum furnace - Google Patents

Abstract

959,367. Electron furnaces. TEMESCAL METALLURGICAL CORPORATION. March 20, 1963 [March 30, 1962], No. 11012/63. Heading H1D. [Also in Division F4] In a continuous process vacuum furnace, a plurality of electron beams melt the stock and heat the metal as it flows in a zig-zag course through the hearth to an outlet mould. As described for refining copper, Fig. 1, shielded electron sources 37, 51, fire beams through apertures in vapour barriers enclosing compartment 19 evacuated by pumps 54. Stock 23 fed into compartment 17 evacuated by pumps 31, is melted into the hearth and flows under the end of barrier 21 into compartment 18 evacuated by pump 64. Heated by bombardment from sources 51 the melt flows in a zigzag path round baffles 66 as illustrated in Fig. 2 (not shown), and overflows into mould 62. Details.-The hearth, mould and vapour barrier are water-cooled in the usual way; the hearth liner 14 and baffles 16 and tundish 61 may be graphite; the hearth may be 4 foot x 6 foot long with a depth of two inches; the electron source may be a filament or filaments 72 mounted in shields to produce a beam which is magnetically deflected through an aperture in the vapour barrier, Figs. 3-6 (not shown); the beams may be scanned across the melt by a magnet assembly surrounding hearth, Fig. 8 (not shown). Alternative arrangements.-The hearth may extend through a number of separately evacuated compartments, Fig. 9 (not shown); a number of furnaces may be arranged in series, Fig. 10 (not shown); the furnace may be used for refining iron or high temperature nickel-based alloys as illustrated in Fig. 7 (not shown), wherein the metal solidifies in the bottom of the hearth and only a thin molten film flows along the top. It is stated that the furnace is suitable for refractory metals such as colombium; hafnium ; tantalum; titanium; zirconium and tungsten.