Purpose.
The vacuum arc furnace “VDP-12.5R” is designed for the manufacturing of high-strength, highly electrically conductive Cu-Nb wires of round and rectangular cross-sections in a wide range of sizes (diameter from 0.05 to 4*6 mm) with an adjustable combination of strength and electrically conductive properties (from the level strength 800-900 MPa with electrical conductivity 80-85% of the electrical conductivity of high-purity copper up to 1100-1500 MPa with electrical conductivity 50-70% of the electrical conductivity of copper).
“VDP-12.5R” ensures the manufacturing of ingots from alloy-composites such as Cu-Nb, Cu-V and others by fusing a consumable electrode with an electric arc into a solid-bottom mold (overall dimensions of the consumable electrode - circumscribed circle diameter - up to 200 mm, height - up to 1700 mm, arc current - 12.5 kA).

The plant consists of the units:
- melting chamber;
- crystallizers No. 1 and No. 2;
- mechanism for moving crystallizers;
- an electrode movement mechanism, including an electromechanical drive for precise movement of the electrode and maintaining the arc length;
- electrode mounting unit;
- vacuum system;
- electrical equipment;
- pneumatic system;
- color television system;
- a computer monitoring and control system that provides automatic process control, visualization and collection (archiving) of technological parameters.

The melting water-cooled chamber has a cylindrical shape. On the upper flange of the chamber there is a lid with a vacuum seal and two peepholes designed for visual monitoring of the melting progress. The lower flange of the chamber is connected to the crystallizer. Support flanges for current copper shoes are placed on the chamber, ensuring current transmission of the chamber directly through the flange to the crystallizer. The chamber has a door for servicing of the internal space. The camera locates on a support mounted on the 2nd floor of the overpass.
Two optical observation devices are installed on the top cover above the peepers. In front of the peepers there are rotating stroboscopic disks with holes to protect the glass.
The crystallizer moving mechanism is designed for installing the crystallizer, moving the crystallizer down under the chamber, raising and lowering the crystallizer when docking with a vacuum chamber. The mechanism consists of a trolley with a drive for moving and a lifting and lowering jack.
The crystallizer is designed to install a mold with a consumable electrode on a tray and smelt ingots in it. The plant is equipped with three standard sizes of crystallizers depending on the diameter of the mold and the diameter of the consumable electrode.
The electrode movement mechanism consists of a rod and two symmetrically located ball screws.
The vacuum system includes two lines: fore-vacuum pumping and the main booster line.
The water-cooling system cools the crystallizer, vacuum chamber, rod, top lid, vacuum system, power supply. The “VDP-12.5R” furnace has a connection to the emergency water-cooling system.

Control system.
The control system of the “VDP-12.5R” plant is built according to the PC-PLC structure and includes a personal computer (upper level), a programmable logic controller (lower level). The operation of the system at the lower level is controlled by a logical programmable controller.
The controller controls the operation of the plant in the following modes:
- manual, supplementing the setup mode with an advisor to the operator-technologist, blocking incorrect operator actions;
- automatic, carrying out the melting work cycle.
The controller performs the functions of technological process control, the computer performs only the terminal control task - visualization of the state of the furnace elements, storage of process history files, events and errors.
The control system of the VDP-12.5R plant performs the following functions:
- control of the operation of the vacuum system in automatic, manual and adjustment modes;
- maintaining the main parameters of the vacuum arc melting process: arc voltage, arc current, speed of vertical movement of the electrode with high accuracy;
- automatic measurement of leakage of the working chamber;
- possibility of recording the parameters of the melting process and archiving the results.