GB855667A - Improvements in or relating to the production of degassed metal - Google Patents

Abstract

855,667. Degassing metals. BRENNAN, J. B. April 2, 1957, No. 10742/57. Class 72 Degassed metal is produced by exposing a molten metal to progressively increased vacuum in successive evacuated chambers. As shown, molten metal may be poured into a container 16 from which it is fed to a spiral shoot 13a in a vacuum chamber 3a and collected in a crucible 9a from which it flows to two series of vacuum chambers 3b, 3c and 3c, 3f. The pressure in the chambers 3c and 3f being the same and less than in the preceding chambers. The metal from the chambers 3c and 3f is fed into a final vacuum chamber 3d from the crucible 9d of which it flows into a mould, in the example, a continuous mould. All the crucibles and pipes leading to the vacuum chambers are provided with heating means, e.g. high frequency coils, in order that the temperature may be controlled. In a modification, Fig. 2 (not shown), one of the vacuum chambers may include a porous tube through which the metal passes in particulate droplets and a spray of aluminium or titanium may be added to the vacuum chamber to assist in obtaining the required vacuum. In a further modification, Fig. 3 (not shown), the metal may be transferred from one chamber to another by means of centrifugal pumps. The final metal may be sprayed on to a moving base to produce a coating. Specifications 748,642, 805,420 and 809,540 are referred to.