초록 ▼

The crucible includes an upstanding sidewall formed of a plurality of internally cooled, metal segments arranged in side-by side relation to form a crucible chamber for receiving the metal to be melted. The segments are separated from one another by longitudinal gaps that communicate on the inside w

The crucible includes an upstanding sidewall formed of a plurality of internally cooled, metal segments arranged in side-by side relation to form a crucible chamber for receiving the metal to be melted. The segments are separated from one another by longitudinal gaps that communicate on the inside with the crucible chamber and extend outwardly to the exterior of the sidewall. The gaps are free of packing material that could constitute a potential source of melt contamination and are so sized in a width dimension where the gap and the chamber communicate as to substantially prevent penetration of molten metal into the gaps when the metal charge is initially melted in the crucible chamber prior to the development of a solidified metal skull. Upper portions of the crucible segments are restrained against outward spreading during use to provide a crucible durable enough for use in production melting applications. The crucible eliminates the need for a CaF2 type lining (skull) and for intersegment refractory packing material, thereby improving melt cleanliness.

대표청구항 ▼

A crucible for heating a metal to the molten state, comprising: (a) an upstanding sidewall formed of a plurality of upstanding metal segments disposed in side-by-side relation about a longitudinal axis of said crucible, each segment having an inner wall facing said axis for forming, together with th

A crucible for heating a metal to the molten state, comprising: (a) an upstanding sidewall formed of a plurality of upstanding metal segments disposed in side-by-side relation about a longitudinal axis of said crucible, each segment having an inner wall facing said axis for forming, together with the inner walls of other segments, a chamber for receiving the metal, each segment being spaced apart from a next adjacent segment by a longitudinal gap that communicates with the chamber and extends outwardly from said chamber to the exterior of said sidewall with each gap between adjacent segments being free of packing material and so fixed in a width dimension where said gap and said chamber communicate as to be small enough to substantially prevent penetration of metal in the molten state therein until a solidified metal skull is formed directly on said inner walls and large enough to sufficiently electrically isolate adjacent segments to allow induction melting of the metal in said chamber, (b) means for inducing an alternating electrical current in the metal in the chamber to heat the metal to the molten state, and (c) means for cooling the segments to eventually form the solidified metal skull directly on said inner walls.