Tubing shape, particularly for fabricating an induction coil.

摘要

Electrically conductive tubing (26) for realizing induction coils (24) having improved efficiencies comprises an outer peripheral portion (28) of conductive material defined by a plurality of side walls (30,32,34) and a single hollow passageway (40). Each side wall has inner surfaces and outer surfaces (42,44). At least one side wall has a curved outer surface (42). The hollow passageway (40) is defined by the inner surfaces and can be either entered within the tubing (26) or spaced apart from the center of the tubing (26). The present invention also defines an induction coil (24) and an induction furnace (10) having an induction coil (24) which utilizes such tubing (26). The curved outer surfaces (42,44) have radius of curvatures which are defined substantially by a function of the tubing width in the axial direction, and spacing between turns of the induction coil. The cross section of the outer surface of the outer peripheral portion of the tubing taken along a transverse axis of the tubing defines a geometric figure. The perimeter of the figure is substantially polygonal with at least one curved side wall (34). <IMAGE>