Abstract: A method is provided for the detection of melt adjacent to the exterior of a bushing in an induction channel furnace. An electrically conductive mesh is disposed around the exterior surface of the bushing facing a refractory that separates the bushing from a channel in which molten metal (melt) flows. The mesh is connected to a grounded voltage source so that when an electrically conductive melt at ground potential in the channel breaches the refractory and penetrates the electrically conductive mesh an electrical circuit is completed through the melt and the grounded voltage source.

Abstract: Apparatus and method are provided for the detection of melt adjacent to the exterior of a bushing in an induction channel furnace. An electrically conductive mesh is disposed around the exterior surface of the bushing facing a refractory that separates the bushing from a channel in which molten metal (melt) flows. The mesh is connected to a grounded voltage source so that when an electrically conductive melt at ground potential in the channel breaches the refractory and penetrates the electrically conductive mesh an electrical circuit is completed through the melt and the grounded voltage source.

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: An AC melt to bushing current detector (FIG. 4) for a channel induction furnace (FIG. 1) which can detect when molten metal from the loop (122) in a saturated inductor (FIG. 5) has come in contact with the metal bushing (236) whereupon the power to the induction coil (234) is turned off, preventing a catastrophic molten metal run out through the bushing (236).

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: An induction-heated furnace having a shell with at least a portion lined with refractory material having walls and a floor. At least one induction heater is mounted to the floor of the furnace refractory material that communicates with the interior of the furnace through a throat. The throat length is substantially longer than the throat length of the induction heater to aid the distribution of molten metal in the furnace.

Abstract: Fine metallic particles are melted in a furnace having an upper region surrounded by a crucible coil and a lower region forming a channel holding a core of a channel inductor. The particles are filled from above into the vessel while simultaneously electrically energizing the inductor with alternating current to inductively heat and fuse the particles and thereby form a melt in the vessel and electrically energizing the coil with alternating current to mix the melt in the vessel while energizing the inductor.

Abstract: A channel inductor and a furnace for melting, holding or refining metal. The channel inductor has a closed-loop core, a primary winding arranged around the core and a refractory lining in which the winding and core is partly enclosed and in which an inductor channel is formed. The channel inductor also has a detector to detect metal penetration of the refractory lining.

Abstract: A hot dip coating pot for containing a coating material in a liquid state. The coating pot comprises a substantially horizontal bottom and substantially vertical side walls. The bottom and the side walls define a first interior volume for containing the coating material. The bottom wall and a lower portion of each of the side walls defines a bottom portion which is separable from an upper portion of the side walls. The bottom portion has a predetermined interior volume less than the first interior volume.

Abstract: A furnace configuration is disclosed in which the furnace is inductively heated by external insulated coils and a susceptor is placed within the charge of reactants away from the outer surfaces of the charge. Consequently, heat is transferred to the charge and the process approaches completion before the insulation is subjected to high temperatures.

Abstract: Induction heating vessels and methods are disclosed. One embodiment of an induction heating vessel is a bottom pouring vessel with a crucible for containing a molten metal to be heated and having an outlet in the bottom. A metallic shell with integral current limiters surrounds the crucible. A stopper is provided for selectably controlling the flow of molten metal through the outlet. A method of preheating an induction heating vessel comprises placing a susceptor inside the vessel prior to charging the vessel with material to be heated and inductively heating the susceptor by an induction coil.

Abstract: A bushing cap used to close a gap in a liquid cooled bushing which surrounds a coil contained in a channel induction furnace. The coil, bushing and bushing cap is further surrounded by a thin refractory layer which is further surrounded by a molten metal loop. The bushing cap and bushing are liquid cooled to maintain a substantial uniform thermal gradient about the thin refractory layer surrounding the bushing and bushing cap. Preferably, this is accomplished by way of a bushing cap having a cooling member attached to a cover and mounted within the bushing gap. A cooling fluid is passed through both the cooling member of the bushing cap and cooling channels within the bushing to maintain a substantial uniform thermal gradient about the thin refractory layer.

Abstract: An apparatus for directing electromagnetic flux near an induction coil comprises a loop-shaped member adapted to conduct electromagnetic flux, defining an axis parallel to the central axis of the induction coil and extending substantially the length of the coil. The loop-shaped member acts as a return circuit for minimizing a stray magnetic field external to the coil.

Abstract: Chemical vapor deposition apparatus has a quartz envelope supporting a resistance heater. A boron nitride pill box configured core supports resistance heater windings. The core has a base having a cylindrical upper portion defining a hollow chamber and an upper annular ring. A circular top includes an upper circular portion and lower circular portion mating with the base. The annular ring surface is in thermal contact with the upper circular portion to transfer heat from the annular ring to the circular top. A zirconia insulator cups the core, providing heat insulation, in conjunction with a heat shield coating in the quartz envelope interior. Arrays of quartz envelope heaters provide for mass production of semiconductors. A horizontal configuration includes a laminar flow head and disposed at an angle to the horizontal.

Abstract: A furnace for melting and melt-heat retaining of metals has two horizontal interspaced furnace vessels which form a melt chamber and each having a side wall facing the side wall of the other furnace vessel, each side wall having an opening horizontally aligned with the opening of the side wall of the other furnace vessel. A single inductor is positioned between these side walls and is formed by an integral block of ceramic having opposite ends abutting the outside of the side walls. The block has a transverse through-hole and two longitudinal through-holes straddling the transverse through-hole and open to the two furnace vessels so that they intercommunicate. The inductor has a core with an energizing coil and having a leg extending through the transverse hole. When the energizing coil is powered a melt in the two longitudinal through-holes is heated by an induced circuit which extends into and through melts in the two furnace vessels.

Abstract: A method for continuously pouring molten metal in an initially substantially unfilled tundish having a channel-type inductor having a channel opening into the bottom portion of the tundish, is done by starting the pourings and the continuous sequential steps of applying power to the inductor when its channel is first covered by the poured metal to form a melt level and the static pressure of the metal is low and while increasing the power rapidly so as to cause incipient pinching in the channel and then momentarily rapidly reducing the power so as to prevent pinching; as the metal level further increases so that the metal's static pressure further increases, again increasing the power rapidly so as to again cause incipient pinching in the channel and then again momentarily rapidly reducing the power so as to prevent pinching; and continuing these sequential steps until the tundish is filled.

Abstract: A channel-type induction furnace of the teapot type comprising a crucible having a bottom, a channel-type inductor in the bottom and having a partially semi-circular channel opening into said bottom, and straight inlet and outlet melt conduits respectively extending to and from the bottom and positioned substantially tangentially with respect to said channel so as to extend straight into and from the channel.

Abstract: A body of molten metal is simultaneously heated and rotated by the use of electromagnetic forces. In one embodiment, the melting of metals by induction heating is improved by using a circular spirally-wound electro-magnetic core located between a central flow channel and six peripherally-located flow channels. Three-phase electrical current is applied to the core windings to form a rotating magnetic field which intercepts the metal in the peripherally-located flow channels. The magnetic field causes heating of the metal in the peripheral channels with negligible heating in the central channel, thereby causing flow of heated metal through the peripheral channels to the bath. The magnetic field also causes rotational motion of the body of molten metal, thereby improving mixing and minimizing surface turbulence. In another embodiment, the electro-magnetic core is immersed in a body of molten metal to be surrounded thereby.

Abstract: Disclosed is a method for measuring the extent of slag deposit buildup in the channel of a channel induction furnace during operation. The method comprises measuring an initial temperature rise factor in the furnace at a time when no slag deposits are present, measuring a subsequent temperature rise factor in the furnace after the furnace has been in operation for a period of time, correcting the subsequent temperature rise factor for any changes in the operating temperature and power levels applied to the furnace which may have taken place between the time of the measurement of the initial temperature rise factor and the time of the measurement of the subsequent temperature rise factor, and determining a quantity which is indicative of the extent of slag deposit buildup in the channel from the difference between the initial and subsequent temperature rise factors.

Abstract: A channel furnace has a magnetic core, for use with a coil in generating a three-dimensional magnetic field, comprising a center core, formed by disk-shaped sheets stacked in cylindrical form, and an outside core surrounding the center core and formed by generally radial sheets having an involute shape. This form of construction of a magnetic core provides for the efficient generation of both axially and radially oriented magnetic fields.