GB811918A - Improvements in or relating to crucibles for melting metals - Google Patents

Abstract

811,918. Crucibles. REPUBLIC STEEL CORPORATION. July 19, 1955, No. 11142/57. Divided out of 811,917 [Group XI]. Class 82(1) [Also in Group. XI] A crucible adapted to enclose heat producing means comprises vertically extending cylindrical concentric inner and outer shells, 4a, 4b separated by an annular space 4c, the ends of the shells being closed to define a shell water jacket 4c shorter than the inner shell; and the crucible has a base plate comprising inner and outer plates 112, 113 having central portions spaced apart to define base water jacket 116. Several arcuate ribs 112a fixed on the underside of the upper base plate 112 abut on the lower plate 113 to support the upper plate 112 and a metal ingot formed in the crucible. A part of the inner base plate 112 projects up within the lower end of the inner shell 4b above the lower end of the shell water jacket 4c so that the entire end portion of the shell exposed to the heating means is directly cooled by the jacket. Several water inlets 104 are spaced at an angle around the periphery of the jacket adjacent its lower end, and several water outlets 105 are arranged adjacent but spaced from the upper end of the jacket 4a. Each outlet 105 is surrounded by a U-shaped tube 106 open at the top ensuring circulation of water through the upper end of the shell jacket 4c. The base water jacket 116 has a diameter greater than its axial length and has several water inlets 117 spaced radially as in Fig. 3 and a central outlet 114 in the base. Each water inlet 117 extends substantially to the middle of the axial length of the jacket and has on its inner end an elbow 118 directing water at angle, preferably perpendicularly to a radius from the outlet 114 so that water is circulated in the base jacket with a swirling motion. The ribs 112a are streamlined to avoid turbulence in the water flowing round them. The crucible is used in melting metals such as zirconium by arcs and is mounted on springs on jacks on a trolley for pressing the crucible up against a shell containing movable electrodes for the arcs, as described in Specification 811,917, which is referred to.