Abstract: This invention aims at providing a silicon electromagnetic casting apparatus for accurate and easy manufacturing of high quality silicon ingots. This apparatus uses a furnace vessel 100, a conductive crucible 200 installed in the internal part of the furnace vessel 100 and an induction coil 300 installed on the outer circumference of the crucible 200. Constant pressure is maintained in the internal part of the furnace vessel 100 using a prescribed gas and the silicon inside the above mentioned crucible 200 is solidified after melting it by induction heating by applying voltage on the induction coil 300. The induction coil 300 is made by placing 2 induction coils 310 and 320 having different induction frequencies one above the other.

Abstract: A dry-break electrical disconnect is provided between an induction melting furnace and a component of the electric induction melting assembly in which the furnace is removably installed for melting in a vacuum or otherwise controlled environmental chamber. Electric power connections are made to the induction melting furnace in a sealed interior volume of the assembly component that can be pressurized and of a different environment than that in the controlled environmental chamber. The assembly component may be a tilting cradle installed in the controlled environment chamber.

Abstract: An open bottom electric induction cold crucible with a slotted wall extending below one or more induction coils surrounding the partial exterior height of the crucible is used in an electromagnetic casting process for the production of ingots. A bottom magnetic shield is provided around the outer perimeter of the crucible's slotted wall in the vicinity of the bottom opening and the bottom termination of the wall slots and the bottom connecting member.

Abstract: A metalloid such as silicon in the form of a preheated solid electrode is purified by a CEVAR purification process by producing an ingot with controlled heating and cool down after the preheated electrode is melted in a CEVAR furnace system using a short CEVAR open-bottomed crucible.

Abstract: A dry-break electrical disconnect is provided between an induction melting furnace and a component of the electric induction melting assembly in which the furnace is removably installed for melting in a vacuum or otherwise controlled environmental chamber. Electric power connections are made to the induction melting furnace in a sealed interior volume of the assembly component that can be pressurized and of a different environment than that in the controlled environmental chamber. The assembly component may be a tilting cradle installed in the controlled environment chamber.

Abstract: The present invention aims at providing a silicon electromagnetic casting apparatus which can prevent the outward deflection of a crucible 200 used in the apparatus. This apparatus has a reaction vessel 100, the conductive crucible 200 installed in the reaction vessel 100 and an induction coil 300 installed on the outer circumference of the crucible 200, wherein constant pressure is maintained in the reaction vessel 100 using a prescribed gas and the silicon inside the crucible 200 is solidified after melting it by induction heating by applying voltage on the induction coil 300. In the apparatus, a hard structure 810 made from electrical insulating material is fitted onto the outer peripheral surface of the crucible 200.

Abstract: A method is provided for output control of a pulse width modulated power inverter used with a substantially resistive, single phase, ac load such as an electro-slag remelting furnace. In one application of the method, during each of the inverter's half cycle outputs, active switching devices are alternatively pulsed on and off during the half cycle so that only half of the switching transients in the half cycle are handled by one of the active switching devices.

Abstract: Apparatus and method are provided for damping the induced fluid flow, particularly in the region of the base plate, in an electrically conductive material that is heated and melted in a cold crucible induction furnace. Damping is accomplished by establishing a dc magnetic field such that flow of the electrically conductive liquid metal in that dc magnetic field would induce eddy currents in the liquid metal which would generate forces that tend to oppose the flow. The dc magnetic field may be established by dc current flow in the ac induction coil that induces current in the material, dc current flow in a separate dc coil, or coils, constructed to prevent excessive induced losses, by discrete magnets, or a combination of any of the three prior methods. The dc magnetic field may also be established by dc current flow in one or more dc coils disposed around a magnetic pole piece located below the base of the furnace.

Abstract: Apparatus and method are provided for damping the induced fluid flow, particularly in the region of the base plate, in an electrically conductive material that is heated and melted in a cold crucible induction furnace. Damping is accomplished by establishing a dc magnetic field such that flow of the electrically conductive liquid metal in that dc magnetic field would induce eddy currents in the liquid metal which would generate forces that tend to oppose the flow. The dc magnetic field may be established by dc current flow in the ac induction coil that induces current in the material, dc current flow in a separate dc coil, or coils, constructed to prevent excessive induced losses, by discrete magnets, or a combination of any of the three prior methods.

Abstract: A cold crucible induction furnace has a slotted-wall with a slotted inner annular protrusion that is disposed around the base of the crucible's melting chamber. The protrusions may be separated from the base by a gap that can be filled with an electrical insulating material. Slots may also be provided in the protrusions and/or the outer perimeter of the base.

Abstract: Apparatus and method are provided for damping the induced fluid flow, particularly in the region of the base plate, in an electrically conductive material that is heated and melted in a cold crucible induction furnace. Damping is accomplished by establishing a dc magnetic field such that flow of the electrically conductive liquid metal in that dc magnetic field would induce eddy currents in the liquid metal which would generate forces that tend to oppose the flow. The dc magnetic field may be established by dc current flow in the ac induction coil that induces current in the material, dc current flow in a separate dc coil, or coils, constructed to prevent excessive induced losses, by discrete magnets, or a combination of any of the three prior methods. The dc magnetic field may also be established by dc current flow in one or more dc coils disposed around a magnetic pole piece located below the base of the furnace.

Abstract: An increased diameter wire is formed by drawing a feed wire through a cooled nozzle located in a cooled crucible, and through a liquid metal bath contained within the crucible. Liquid metal freezes onto the feed wire as it passes through the bath, thereby increasing the diameter of the feed wire to form an increased diameter wire product. The invention is particularly suited to forming a wire from a metal composition that would undesirably react with refractory apparatus.

Abstract: Apparatus and method accomplishes the precision pouring of a liquid from a vessel to a predetermined position with a controlled rate of flow. Independently controllable horizontal and vertical translation of the vessel is accomplished by using two rotational elements lying in substantially parallel planes, with the rotational axis of the second element passing through the first element, and having offset first and second axes of rotation. Independently controlled tilting of the vessel about a third axis of rotation that passes through the second element maintains a desired pour rate and aim point for the pour stream. The apparatus is particularly useful when the vessel and the receptacle that receives the liquid are inside a sealed chamber.

Abstract: A process and apparatus for electro-slag remelting including a cooling medium directed towards the electrode surface adjacent its entry into the slag layer. The cooling medium retards the melting of the electrode periphery within the slage so as to form a concave surface at the electrode tip, such that the molten metal from the electrode tip moves from the center of the electrode toward the outer periphery. The remelting of the electrode in this manner resulting in a shallower molten metal pool below the slag layer and a higher current density in the slag. The invention further redistributes the heat generated in the slag layer from the center towards the outer edge of the molten metal pool progressively formed within the mould and results in an improved smoothness on the surface of the ingot.

Abstract: A method and apparatus for controlling electrode drive speed in a consumable electrode furnace. The electrode drive speed is regulated at a base speed computed from measured changes in physical characteristics of the electrode or ingot, such as changes in weight, as the melt proceeds. The base speed also takes into consideration the known geometry of the electrode, the furnace mold or crucible, the density of the ingot material, and the speed of movement of the bottom of the ingot if any. This base speed is increased or decreased by a trim speed determined from measurement of an electrical phenomenon associated with the consumable electrode process, which electrical phenomenon has a relatively long term value related to the distance between the bottom surface of the electrode and the top surface of the ingot.

Abstract: An electroslag remelting furnace with a power connection at the base and a coaxial conductor to eliminate the deleterious effects of magnetic fields upon the pool of molten metal. The furnace may have a vertically moveable crucible, and also a top supported inner mold to form a hollow ingot, for containing the molten portions of the metal as the ingot is formed. The upper portions of the annulus between an inner and outer mold can be greater in width than the width of the lower portion of the annulus to permit increased spacing between the electrodes and the walls of the molds or to permit the use of electrodes of a larger diameter than the width of the lower portion of the annulus.

Abstract: A melt rate control system for consumable electrode remelting uses a closed loop control system to control electrical power and hence the electrode melt rate. The control equation is purposely adjusted to cause the melt rate to initially exceed the steady state melt rate in a controlled manner to take advantage of the higher permissible melt rate at the bottom of an ingot. Initially, the melting current is held at a steady level sufficiently high to cause the melt rate to exceed the steady state melt rate. The initial current is then reduced in a controlled manner to bring the melt rate to the steady state condition. The length of time and amount of excessive melt rate is matched to the higher permissible melt rate at the bottom of an ingot.

Abstract: A method and apparatus for casting a plurality of ingots by forming a pool of molten metal in a main mold section which is in direct, open communication with a plurality of ingot mold sections by flowing the molten metal from the pool into the ingot mold sections. An electrode and a conductor establish an electrical current path, through the molten metal pool, which does not enter the ingot mold sections, and the cast ingots are electrically isolated at their lower ends.