A multi-section coil enhanced stirring system wherein only one of the coils is powered from a single-phase AC source to enhance the stirring of the metal.

A method and an apparatus for automatically detecting the intactness of ground electrodes in the bath of an induction furnace are described. According to the method a low DC or AC current is applied to an additional insulated electrode extending through the furnace bottom and being in connection with the melt. After melting of the charge this current is measured and compared with a reference value. If the magnitude of the current drops below the reference value an alarm signal is generated. Furthermore, methods and devices for localizing a ground fault are described. By this, the security of the operation of an induction furnace is improved.

A crucible device with temperature control design includes a crucible body, an induction coil unit, a nozzle flange body and a melt delivery tube and a temperature control unit. The induction coil unit surrounds the crucible body, provides a heat source during use, and is configured to enable a metal material to melt and produce a melt having a melting skull. The melt delivery tube is communicated via the nozzle flange body to a bottom of the crucible body and is configured to deliver the melt from the crucible body. The temperature control unit includes a microprocessor, a heater and a temperature sensor which are electrically coupled to each other, and are configured to control a curve of the melting skull to drop to a preset position.

An alloy powder manufacturing device with temperature control design includes: a crucible unit, for accommodating a melt; a melt delivery tube, for delivering the melt from the crucible unit; a temperature control unit, inductively heating the melt delivery tube and the melt therein, to generate an overtemperature melt, and enabling the temperature of the overtemperature melt leaving the melt delivery tube to reach a predetermined temperature; and a powder spray unit in communication with the outlet of the melt delivery tube, for impacting and atomizing the overtemperature melt having the predetermined temperature and then quickly solidifying the overtemperature melt to form alloy powders.

Various embodiments provide an apparatus and methods for containing the molten materials within a melt zone during melting. The apparatus may include a vessel configured to receive a material for melting therein and an induction coil with unevenly spaced turns along its length. Induction coil can have a series of turns acting as a first (e.g., load) induction coil and a series of turns acting as a second (e.g., containment) induction coil. The material in the vessel can be heated and contained by the separated turns of the induction coil. A plunger can also assist in containing material during melting. Once the desired temperature is achieved and maintained for the molten material, operation of the induction coil can be stopped and the molten material can be ejected from the vessel into a mold using the plunger.

A method and an apparatus for detecting a ground fault in an induction furnace as well as an induction furnace are described. When a ground fault is detected by means of the ground-fault detector the ground fault is localized. By doing this it is determined if the ground fault is caused by a failure of the refractory lining or by other reasons. If the ground fault is caused by other reasons it is ascertained if it is caused by a defective magnetic yoke insulation. Furthermore, it can be ascertained which magnetic yoke of the induction furnace causes a ground fault. In this manner the induction furnace can be operated with improved security and smaller expense.

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.

Plant for melting metal materials comprising at least a heating unit (11) provided with a container (13) to contain the mainly metal materials and with at least an induction heating device (22) configured to heat the mainly metal materials contained in the container (13). The plant also comprises a transfer unit (25) disposed downstream of the heating unit (11) and configured to move, substantially continuously, the mainly metal solid materials exiting from the heating unit (11) to a melting furnace (12). The container (13) is provided with an aperture (16) through which the mainly metal material, heated and in a solid state, is discharged onto the transfer unit (25), and opening/closing members (17) are associated with the aperture (16), commanded by an actuator (19) and configured to open, close and choke the aperture (16) in order to regulate the delivery of the metal materials that is discharged onto the transfer unit (25).

Apparatus to heat and transfer mainly metal materials to a melting furnace (12), the apparatus comprising a transporter device (13) configured to move the materials continuously to the melting furnace (12), and at least an induction heating unit (28) associated with the transporter device (13) and configured to heat by electromagnetic induction the materials moved in the transporter device (13), keeping them in a solid state.

An adjustable shunt system of an induction furnace and method of use thereof. The adjustable shunt system may include a shunt that operably engages with at least one cooling coil of the induction furnace and a power coil of the induction furnace. The adjustable shunt system may also include a support column operably engaged with an outer shell of the induction furnace. The adjustable shunt system may also include at least one shunt drive assembly operably engaged with the support column and the shunt. The at least one shunt drive assembly is configured to automatically adjust the shunt along an axis angled relative to the support column.