Abstract: Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

Abstract: A variable width transverse flux electric inductor has a fixed powered coil section and associated box-like moveable passive coil sections that electromagnetically couple with magnetic flux generated by current flowing through the fixed powered section. The passive coil sections can be transversely moved across the workpiece to accommodate induction heating of workpieces having different widths or track movement of the workpiece. Alternatively the fixed powered coil section and associated moveable coil sections may be connected to each other through flexible connections, sliding contacts or other means, such as clamps, so that an electrical connection can be maintained between both in any relative position.

Abstract: An electric induction furnace for heating and melting electrically conductive materials is provided with a lining wear detection system that can detect replaceable furnace lining wear when the furnace is properly operated and maintained.

Abstract: An electric induction gas-sealed tunnel furnace and process are provided. The exterior of the furnace's enclosure that forms a closed tunnel region is surrounded at least along its longitudinal length by a gas-tight barrier chamber that can be filled with a barrier gas to a different pressure than the pressure of the process gas in the closed tunnel region of the furnace. The inductors used to induction heat strips or plates in the closed tunnel region can be positioned within or outside of the gas-tight barrier chamber around the longitudinal length of the closed tunnel region.

Abstract: A molten metal holding and pouring box with a rectangular-shaped upper section and a pyramidal-shaped lower section provides a relatively constant flow of molten metal being poured from the box through each of two bottom nozzles into two separate foundry molds at the same time. The two bottom nozzles are contained in a unitary dual nozzle assembly that facilitates replacement as required by wear, or a change in location of the sprue cups in the two separate foundry molds being filled with molten metal.

Abstract: An apparatus and process are provided for controlling the heating and melting of a material that is non-electrically conductive in the solid state and is electrically conductive in the non-solid state. Power is selectively directed between coil sections surrounding different zones of the material in a susceptor vessel by changing the output frequency of the power supply to the coil sections. Coil sections are at least one active coil section, which is connected to the output of the power supply, and at least one passive coil section, which is not connected to the power supply, but is connected in parallel with a tuning capacitor so that the at least one passive coil section can be selectively operated at, or near, resonant frequency when the transition material in the vessel is molten.

Abstract: Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

Abstract: Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

Abstract: An apparatus and process are provided for scan induction heating of a workpiece. The workpiece is moved through an inductor to inductively heat treat features of the workpiece with electric power of varying frequency and duty cycle to control the magnitude of electric power as the frequency changes. Alternatively the inductor is moved along the workpiece to inductively heat treat features of the workpiece with electric power of varying frequency and duty cycle to control the magnitude of electric power as the frequency changes, or a combination of simultaneous inductor and workpiece movement may be used.

Abstract: An impeder for use in an electric induction welding process is provided. A cooling medium is circulated around the exterior of the impeder's magnetic material with the impeder entry and exit passages for the cooling medium located on opposite sides of the impeder.

Abstract: Solid or semi-solid feedstock is melted in an open bottom electric induction cold crucible furnace. Directionally solidified multi-crystalline solid purified material continuously exits the bottom of the furnace and may optionally pass through a thermal conditioning chamber before being gravity fed into a transport mold where an ingot of the purified multi-crystalline solid material is transported to a remote holding area after the transport mold is filled with the multi-crystalline material and cut from the continuous supply of material. Cool down of the ingot is accomplished remote from the open bottom of the electric induction cold crucible furnace.

Abstract: Apparatus and method are provided for making the longitudinal temperature distribution of the bulbous end of a longitudinally oriented workpiece, such as a rail's head, generally uniform when the head has a non-uniform longitudinal temperature distribution. A combination of crown and skirt electric inductors is used to achieve the generally uniform temperature distribution by modulating the magnetic field intensity produced by current flow through one or more of the combination of crown and skirt inductors as required for the non-uniformly heated regions of the rail's head.

Abstract: The present invention is apparatus for, and method of, purification of silicon by electric induction heating and melting of silicon in a crucible or susceptor vessel, with subsequent directional partial cooling of the silicon melt to an initial amorphous-to-crystalline (solidification) temperature to produce a directionally solidified purified quantity of silicon and a separate quantity of high impurity silicon. The quantity of high impurity silicon is removed from the vessel and the purified quantity of silicon at solidification temperature is remelted in the vessel for removal from the vessel or further processing.

Abstract: An impeder for use in an electric induction welding process is provided. A cooling medium is circulated centrally through the impeder's magnetic material with the impeder entry and exit passages for the cooling medium located on opposite sides of the impeder.

Abstract: A reinforced electric induction gas sealed tunnel furnace is provided. The assembled tunnel furnace has a tunnel wall that has the exterior wall transversely surrounded by structural reinforcing elements that give the tunnel structural strength to withstand a pressure differential between the interior and exterior of the tunnel, for example, when the tunnel interior environment is a vacuum and the tunnel exterior environment is at atmospheric pressure. One or more inductors form the induction coil system for the N tunnel furnace and can be located external to the tunnel wall, but within or adjacent to, the structural reinforcing elements. In alternative arrangements the structural reinforcing elements may be oriented with the length of the tunnel and installed either within or external to the tunnel. The tunnel and the structural reinforcing elements are sufficiently electromagnetically transparent to not interfere with inductive heating of a strip passing through the tunnel.

Abstract: Apparatus and process for heating and melting a material in a susceptor vessel are provided wherein phase synchronized ac voltage is supplied from a separate power source to each one of at least two induction coils in separate zones around the vessel. Power magnitude from each source to an induction coil is controlled by pulse width control of the source's output voltage. Output frequency from each source is either fixed or variable based upon the electrically conductive state of the material. Optional electromagnetic stirring is achieved by establishing a phase shift between the voltage outputs of the power supplies after the material in the susceptor vessel has melted.

Abstract: An openable induction coil is provided. An electromagnetically shielded inductor assembly can be formed from the openable induction coil and an electromagnetically shielded enclosure into which the coil can be inserted. The induction coil can be pivoted open while in the shielding enclosure without complete disassembly of the enclosure. In some examples of the invention, a dynamic “curtain” of a gas is injected through spaces between opening portions of the coil and adjacent sections of the shielding enclosure, and into the interior of the induction furnace formed by the openable induction coil when it is in the closed position.

Abstract: The present invention relates to an electric channel inductor assembly and method of forming an electric channel inductor assembly. A nonremovable, hollow, nonmagnetic channel mold is used to form the one or more flow channels of the assembly. A heated fluid medium is circulated in the hollow interior of the mold after the mold is situated in the assembly to heat treat the refractory surrounding the exterior walls of the mold. After heat treatment a liquid is supplied to the hollow interior of the mold to chemically dissolve the mold.

Abstract: The present invention is apparatus for, and method of, purification of silicon by electric induction heating and melting of silicon in a crucible or susceptor vessel, with subsequent directional partial cooling of the silicon melt to an initial amorphous-to-crystalline (solidification) temperature to produce a directionally solidified purified quantity of silicon and a separate quantity of high impurity silicon. The quantity of high impurity silicon is removed from the vessel and the purified quantity of silicon at solidification temperature is remelted in the vessel for removal from the vessel or further processing.

Abstract: Apparatus and method are provided for electric induction heating and/or stirring of a molten electrically conductive composition in a containment vessel with the apparatus being removably insertable in the molten composition. An induction coil embedded in refractory or a coating is submerged in the composition and used to heat and/or stir the molten composition either externally or internally to the refractory or coating.