A cold crucible is described, having a normally vertical side wall, formed of a plurality of vertical concentric tube pairs disposed side by side, each tube pair consisting of an outer tube having a closed upper end and an open lower end and an inner tube spaced inwardly from the outer tube and having open upper and lower ends, plural header means respectively connected to the lower ends of each of the tubes in pairs and means for connecting water supply and return conduits to the respective header means.
U.S. Pat. 4,058,668, Nov. 15, 1977; Chem. Abstr. Not Found