A resistance annealing furnace for annealing a metal wire, strand, string, wire rod or strap having at least two electric axes provided with respective pulleys to convey the metal wire and a DC voltage generator suppliable with an AC voltage to generate an annealing voltage applied between the two electric axes so as to provoke the annealing due to Joule effect. The DC voltage generator has active supplying means supplied with the AC voltage so as to generate an intermediate DC voltage, a pulse width modulator to transform the intermediate voltage into a first PWM voltage with the same amplitude, a voltage transformer to transform the first PWM voltage into a second PWM voltage with a smaller amplitude, and a voltage rectifier stage to transform the second PWM voltage into the annealing voltage.

An assembly provides electrical current to molten glass in a glass melting tank. The assembly includes a structure having an electrode that is in contact with the molten glass, and a fluid-cooled connection apparatus. The fluid-cooled connection apparatus includes a first connection element electrically connected to a current source and a second connection element electrically connected to the current source, where the first and second connection elements are spaced apart from each other; and an electrical cross-connect strut having a first end secured to the first connection element and a second end secured to the second connection element. The assembly also includes a bus bar electrically connected to the fluid-cooled connection apparatus and to an electrode. The current source provides a current to the molten glass via the structure and the electrode for heating the molten glass through resistive heating.

An assembly provides electrical current to molten glass in a glass melting tank. The assembly includes a structure having an electrode that is in contact with the molten glass, and a fluid-cooled connection apparatus. The fluid-cooled connection apparatus includes a first connection element electrically connected to a current source and a second connection element electrically connected to the current source, where the first and second connection elements are spaced apart from each other; and an electrical cross-connect strut having a first end secured to the first connection element and a second end secured to the second connection element. The assembly also includes a bus bar electrically connected to the fluid-cooled connection apparatus and to an electrode. The current source provides a current to the molten glass via the structure and the electrode for heating the molten glass through resistive heating.

A resistance annealing furnace for annealing a metal wire, strand, string, wire rod or strap having at least two electric axes, which are provided with respective pulleys for conveying the metal wire, and DC voltage generator means suppliable by an AC voltage source to generate an annealing voltage applied between the two electric axes. The DC voltage generator means has a first voltage rectifier stage connectable to the AC voltage source to generate an intermediate DC voltage, an active power filter, connected so as to compensate the current harmonics at the input of the first voltage rectifier stage, a pulse width modulator to transform the intermediate voltage into a first PWM voltage, a voltage transformer to transform the first PWM voltage into a corresponding second PWM voltage, and second voltage rectifier means to transform the second modulated PWM voltage into the annealing voltage.

A resistance annealing furnace for annealing a metal wire, strand, string, wire rod or strap having at least two electric axes, which are provided with respective pulleys for conveying the metal wire, and DC voltage generator means suppliable by an AC voltage source to generate an annealing voltage applied between the two electric axes. The DC voltage generator means has a first voltage rectifier stage connectable to the AC voltage source to generate an intermediate DC voltage, an active power filter, connected so as to compensate the current harmonics at the input of the first voltage rectifier stage, a pulse width modulator to transform the intermediate voltage into a first PWM voltage, a voltage transformer to transform the first PWM voltage into a corresponding second PWM voltage, and second voltage rectifier means to transform the second modulated PWM voltage into the annealing voltage.

A heating chamber (1) for a heating furnace is proposed, with which electrothermal vaporization of impurities from samples can be effected in order to be able to then analyze them spectrometrically. The heating chamber has a wall (3), a sample reception area (5), a nozzle area (7) and two electrical connection areas (9, 11). The heating chamber (1) is specially configured such that an electric current flows through the wall (3) in such a way that a heating capacity caused by it is higher in the nozzle area (7) than in the sample reception area (5). For example, the electrical connection areas (9, 11) may be arranged in a radial direction remoter from the longitudinal axis (8) than a part of the wall (3) surrounding the nozzle area (7), and the heating chamber (1) may be configured, for example by means of a locally constricted area (13), in such a way that the current between the two electrical connection areas (9, 11) is predominantly conducted radially inwards towards the part of the wall (3) surrounding the nozzle area (7). Advantageous heat distribution in the heating chamber (1) achievable thereby may have a positive effect on the analysis of sample impurities.

A heating chamber (1) for a heating furnace is proposed, with which electrothermal vaporization of impurities from samples can be effected in order to be able to then analyze them spectrometrically. The heating chamber has a wall (3), a sample reception area (5), a nozzle area (7) and two electrical connection areas (9, 11). The heating chamber (1) is specially configured such that an electric current flows through the wall (3) in such a way that a heating capacity caused by it is higher in the nozzle area (7) than in the sample reception area (5). For example, the electrical connection areas (9, 11) may be arranged in a radial direction remoter from the longitudinal axis (8) than a part of the wall (3) surrounding the nozzle area (7), and the heating chamber (1) may be configured, for example by means of a locally constricted area (13), in such a way that the current between the two electrical connection areas (9, 11) is predominantly conducted radially inwards towards the part of the wall (3) surrounding the nozzle area (7). Advantageous heat distribution in the heating chamber (1) achievable thereby may have a positive effect on the analysis of sample impurities.

Techniques and apparatus for electromagnetically stirring a melt material are disclosed. In accordance with some embodiments, the system may include a containment vessel within which a melt material may be disposed. The melt material may include, for example, an electrically conductive alloy, which optionally may be non-ferromagnetic and/or glass-forming. In its molten state, the melt material may have alternating current (AC) applied directly thereto while being immersed in a magnetic field, which may be static or dynamic, depending on the desired stirring effect. Application of the AC and magnetic field may continue as the melt material cools and solidifies, the sinusoidal nature of the AC and the Lorentz force of the magnetic field providing convective motion which tends to agitate the molten melt material in a manner which may realize an improvement in heat transfer and chemical homogeneity of the resultant cast solid.

Techniques and apparatus for electromagnetically stirring a melt material are disclosed. In accordance with some embodiments, the system may include a containment vessel within which a melt material may be disposed. The melt material may include, for example, an electrically conductive alloy, which optionally may be non-ferromagnetic and/or glass-forming. In its molten state, the melt material may have alternating current (AC) applied directly thereto while being immersed in a magnetic field, which may be static or dynamic, depending on the desired stirring effect. Application of the AC and magnetic field may continue as the melt material cools and solidifies, the sinusoidal nature of the AC and the Lorentz force of the magnetic field providing convective motion which tends to agitate the molten melt material in a manner which may realize an improvement in heat transfer and chemical homogeneity of the resultant cast solid.

A graphitization furnace has a furnace structure including a support part within a furnace chamber, and a gate valve. The gate valve in an open state thereof after a graphitization process dumps a pack material within the furnace chamber in a state in which carbon bodies are located within the furnace chamber, and the support part catches the carbon bodies as a level of the carbon bodies lowers with a decrease in an amount of the pack material remaining within the furnace chamber.