Abstract: An induction furnace apparatus and method for reducing the magnetic field produced by the operation of the furnace. The induction furnace including a refractory vessel, an induction coil, and an outer shell having a layer of metallic and magnetically permeable material. The metallic and magnetically permeable material comprising a plurality of elements having a shape and size that is chosen to maximize the packing density of elements throughout the layer. The outer shell further including a top, base, and sidewall arranged about the refractory vessel such that the metallic and magnetically permeable material is formed between the refractory vessel and the outer shell. The invention provides a method for casting metallic and magnetically permeable material with or without a non-conductive matrix. The castings can be formed into inserts or incorporated into the top, base, and side wall of the outer shell.

Abstract: An induction heating coil assembly for use in a roller induction heating line has a magnetic shunt for receiving a portion of an electromagnetic field generated along the axis of the induction coil and directing that portion along a path parallel to a workpiece passing along the heating line. This flux path ensures that eddy currents induced in the workpiece flow primarily perpendicular to the axis of the workpiece, and not along the axis of the workpiece where they could cause arcing between the moving workpiece and the conveyor rolls.

Abstract: A galvanizing apparatus comprising a vessel for containing a melt of molten metal. The vessel includes at least one conical projection in its side walls around which an induction heating coil is wound to generate a uniform and continuous stirring pattern of molten metal that penetrates deeply into the pot. In a second embodiment, the galvanizing vessel has no projections from its side walls, but comprises instead one or more flat inductors disposed on the exterior wall of the vessel. The flat inductor is surrounded by magnetic return shunts for directing the magnetic force field created by the inductor.

Abstract: An induction heating coil assembly for use in a roller induction heating line has a magnetic shunt for receiving a portion of an electromagnetic field generated along the axis of the induction coil and directing that portion along a path parallel to a workpiece passing along the heating line. This flux path ensures that eddy currents induced in the workpiece flow primarily perpendicular to the axis of the workpiece, and not along the axis of the workpiece where they could cause arcing between the moving workpiece and the conveyor rolls.

Abstract: Electrically conductive tubing for realizing induction coils having improved efficiencies comprises an outer peripheral portion of conductive material defined by a plurality of side walls and a single hollow passageway. Each side wall has an inner and outer surface. At least one side wall has a curved outer surface. The hollow passageway is defined by the inner surfaces and can be either centered within the tubing or spaced apart from the center of the tubing. The present invention also defines an induction coil and an induction furnace having an induction coil which utilizes such tubing. The curved outer surface has a radius of curvature which is 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.

Abstract: Apparatus for inductively melting a quantity of metal without a container includes a first induction coil having a plurality of turns defining a volume for receiving a quantity of metal, the first induction coil being adapted to exert a force on the metal, a second induction coil having a plurality of turns at substantially right angles to the turns of the first induction coil, the second induction coil, being disposed within said volume coaxial with the first induction coil. Both the first and second induction coils have connectors thereon for connecting the coils to at least one power supply for energizing the first and second induction coils. A support is provided for supporting the metal from below, and has an opening through it. The support includes a raised segmented rim around substantially its entire periphery. The support is maintained at a preselected temperature. In an alternate embodiment, structure is also provided for imparting rotational motion to the support.

Abstract: Method and apparatus for internally heating solid bodies using electromagnetic induction. The method comprises generating an electromagnetic induction field and causing it to induce the flow of an electric current in a preselected portion of a solid body to be heated. The electric current has a direction and magnitude sufficient to cause internal heating of the preselected portion of the body. The induction field and the body are rotated relative to one another for causing the direction of the induced current to rotate relative to the body about a preselected location to cause overheating at the preselected location. The body is cooled, except for the preselected portion to be heated. The apparatus comprises a coil for generating an electromagnetic induction field for inducing the flow of an electric current in a preselected portion of a solid body to be heated. The electric current has a direction and magnitude sufficient to cause internal heating of the preselected portion of the body.