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: 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: 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: An integrated process control installation is provided for electric induction metal melting furnaces with variable furnace states. The integrated process control installation can include supporting charge delivery and slag removal installations, and furnace process operations for process control of melting metal in the furnaces. The variable furnace states, supporting installations, and furnace process operations are controlled by a supporting processing installation, while a robotic apparatus performs the furnace process operations.

Abstract: A method for setting the operating frequency of a forge welding machine for a preferred width of the of the heat affected zone during a forge weld. A computer program executes a self-tuning routine to determine the operating frequency in response to an inputted value of a preferred width of the heat affected zone. The operating power setting for the forge welding machine may also be determined in combination with the operating frequency in response to an inputted value of weld temperature.

Abstract: The present invention is apparatus for, and method of, heating, melting and purifying a material by electric induction heating in a susceptor furnace. Non-electrically conductive solid charge may initially be placed in the furnace. Output frequency from a power source supplying current to one or more induction coils surrounding the furnace is selected to maximize magnetic coupling with the susceptor material in the susceptor furnace to induce eddy current heating in the material. Heat transfers by conduction from the susceptor material to the non-electrically conductive charge placed in the susceptor furnace to melt the charge. Output frequency is reduced as the charge melts and becomes electrically conductive to enhance magnetic coupling with the melt in the furnace. Degassing of impurities from the melt can be achieved by bubbling a gas through the melt while the surface level of the melt is maintained at vacuum.

Abstract: Apparatus and method are provided for heating and melting of materials by electric induction heating of susceptor components in a crucible of the furnace. The susceptor components comprise at least an array of susceptor rods arranged around the inner perimeter of the crucible. A susceptor base may also be provided in the crucible with connection to one end of the susceptor rods. One or more susceptor tubes may also be used within the interior volume of the crucible. Alternating current flow through one or more induction coils surrounding the exterior of the crucible generate magnetic flux fields that couple with the susceptor components to inductively heat the susceptor components. Heat from the susceptor components transfers to the material in the crucible to heat and melt the material.

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 and between the interior of the impeder's high temperature enclosure and the exterior of the magnetic material within the impeder with the impeder entry and exit passages for the cooling medium located on the same side of the impeder.

Abstract: An apparatus and process are provided for casting liquid metals into molds in a casting furnace comprising a controlled environment melt chamber and a mold lock chamber. A mold is supplied to the controlled environment melt chamber for a pour, and removed from the same chamber via a mold lock chamber. A mold transport system moves the mold through the mold lock chamber. The mold transport system comprises a rotary screw drive, a cylinder screw drive, or hydraulic drive located external to the furnace. Alternatively the mold transport system comprises a rack and worm screw drive.

Abstract: A system and method for computing the parameters of a forge welding machine for the forge welding of one or more materials is provided. A computer program executes a self-tuning routine to compute the operating frequency and operating power setting for the forge welding machine in response to an inputted width of the heat affected zone and an inputted weld temperature.

Abstract: A current fed inverter with duty cycle regulation of dc current to the input of the inverter is provided to increase the magnitude of inverter output power while operating a resonant load at resonant frequency. The regulator duty cycle period is synchronized to the period of the output current of the inverter so that there are two regulator periods for each single output current period of the inverter. Duty cycle regulation may be provided by a single pulse in the regulator period, or a series of pulses in the regulator period. Output power magnitude greater than that available at full duty cycle can be provided by operating the inverter at off resonance. Multiple current fed inverters may be connected to individual coil sections around a crucible and selectively interconnected for a heating or melting mode, or a stir mode.

Abstract: An electric induction heating and melting system is provided for inducing heat in an electrically conductive material placed in a containment vessel by bringing a moveable one or more induction coils at least partially enclosed in a refractory material in close contact with the surface level of the melt in the vessel while supplying ac power to the one or more induction coils. The moveable one or more induction coils can be kept in close contact with the surface level of the melt as the height of the melt in the vessel changes.

Abstract: An integrated process control installation is provided for electric induction metal melting furnaces with variable furnace states. The integrated process control installation can include supporting charge delivery and slag removal installations, and furnace process operations for process control of melting metal in the furnaces. The variable furnace states, supporting installations, and furnace process operations are controlled by a supporting processing installation, while a robotic apparatus performs the furnace process operations.

Abstract: A current fed inverter with duty cycle regulation of dc current to the input of the inverter is provided to increase the magnitude of inverter output power while operating a resonant load at resonant frequency. The regulator duty cycle period is synchronized to the period of the output current of the inverter so that there are two regulator periods for each single output current period of the inverter. Duty cycle regulation may be provided by a single pulse in the regulator period, or a series of pulses in the regulator period. Output power magnitude greater than that available at full duty cycle can be provided by operating the inverter at off resonance. Multiple current fed inverters may be connected to individual coil sections around a crucible and selectively interconnected for a heating or melting mode, or a stir mode.

Abstract: An apparatus and process are provided for casting liquid metals into molds in a casting furnace comprising a controlled environment melt chamber and a mold lock chamber. A mold is supplied to the controlled environment melt chamber for a pour, and removed from the same chamber via a mold lock chamber. A mold transport system moves the mold through the mold lock chamber. The mold transport system comprises a rotary screw drive, a cylinder screw drive, or hydraulic drive located external to the furnace. Alternatively the mold transport system comprises a rack and worm screw drive.

Abstract: An apparatus and process are provided for casting liquid metals into molds in a casting furnace comprising a controlled environment melt chamber and a mold lock chamber. A mold is supplied to the controlled environment melt chamber for a pour, and removed from the same chamber via a mold lock chamber. A mold transport system moves the mold through the mold lock chamber. The mold transport system comprises a rotary screw drive, a cylinder screw drive, or hydraulic drive located external to the furnace. Alternatively the mold transport system comprises a rack and worm screw drive.

Abstract: Molten metal, or other electrically conductive material, in a vessel can be inductively heated, and simultaneously inductively stirred. A single-phase ac supply provides induction heating power to at least one set of three induction coil sections surrounding the vessel. A three-phase ac supply provides induction stirring power to at least one set of three induction coil sections surrounding the vessel. The single-phase ac supply is capacitively connected to the coil sections to form a heat resonance circuit, and the three-phase ac supply is inductively connected to the coil sections to form a stir resonance circuit. The heat circuit capacitive elements provide a sufficient impedance to the output of the three-phase ac supply to block power transfer from its output to the input of the single-phase supply. The stir circuit inductive elements provide a sufficient impedance to the output of the single-phase supply to block power transfer from its output to the input of the three-phase supply.

Abstract: Molten metal, or other electrically conductive material, in a vessel can be inductively heated, and simultaneously inductively stirred. A single-phase ac supply provides induction heating power to at least one set of three induction coil sections surrounding the vessel. A three-phase ac supply provides induction stirring power to at least one set of three induction coil sections surrounding the vessel. The single-phase ac supply is capacitively connected to the coil sections to form a heat resonance circuit, and the three-phase ac supply is inductively connected to the coil sections to form a stir resonance circuit. The heat circuit capacitive elements provide a sufficient impedance to the output of the three-phase ac supply to block power transfer from its output to the input of the single-phase supply. The stir circuit inductive elements provide a sufficient impedance to the output of the single-phase supply to block power transfer from its output to the input of the three-phase supply.

Abstract: An induction heating and melting system uses a crucible formed from a material that has a high electrical resistivity or high magnetic permeability, and one or more inductor coils formed from a wound cable consisting of multiple individually insulated copper conductors to form an induction furnace that, along with its associated power supply, provides a compact design. The system components are air-cooled; no water-cooling is required. The crucible may alternatively be shaped as a tunnel or enclosed furnace.

Abstract: Molten metal, or other electrically conductive material, in a vessel can be inductively heated, and simultaneously inductively stirred. A single-phase ac supply provides induction heating power to at least one set of three induction coil sections surrounding the vessel. A three-phase ac supply provides induction stirring power to at least one set of three induction coil sections surrounding the vessel. The single-phase ac supply is capacitively connected to the coil sections to form a heat resonance circuit, and the three-phase ac supply is inductively connected to the coil sections to forma a stir resonance circuit. The heat circuit capacitive elements provide a sufficient impedance to the output of the three-phase ac supply to block power transfer from its output to the input of the single-phase supply. The stir circuit inductive elements provide a sufficient impedance to the output of the single-phase supply to block power transfer from its output to the input of the three-phase supply.