1. Purpose. Technological processes used in the equipment.
"UPU-10S" plant is intended for deposition of metal materials to the surfaces of products via plasma spraying of wear-resistant, corrosion-resistant, heat-protective, sealing and other special coatings.


2. Features of the physical processes used.
The operation of the "UPU-10S" plasma deposition plant consists of applying coatings using a plasma jet by depositing particles of the sprayed material onto the product, introduced into the plasma jet in the form of a powder.
When colliding with a product, particles that are in a molten or plastic state are deformed and embedded in the micro-irregularities of the product or plastically deform it with the formation of common points of physical and chemical interaction, ensuring adhesion strength and coating density. The formation of a coating layer of the required thickness is carried out by layer-by-layer spraying when moving the plasma torch relative to the sprayed surface.


3. Plant design.
"UPU-10S" plant has the form of a capsule with noise-absorbing walls. The capsule is equipped with a mechanical door for loading parts. There are observation windows on the capsule door and sidewall.

Inside the capsule, there is a positioning mechanism, consisting of a plasma torch positioning mechanism, a rotator (positioner) and a three-jaw lathe chuck.

Main plant components.
"UPU-10S" plant includes the following main components:
- Positioning mechanism;
- Rotator (positioner);
- Purge system;
- Water cooling system;
- Dispenser;
- Trestlework;
- Plasmatron;
- Ramp;
- Gas cabinet;
- Control cabinet;
- Electrical wiring;
- Plasma spray straightener “VPN-650”.

Plasma torch positioning mechanism.
The plasma torch positioning mechanism allows smooth movement of the plasma torch along the X (horizontal movement) and Y (vertical movement) axes according to the control program.

Rotator (positioner).
The rotator (positioner) is equipped with a self-centering lathe chuck, allowing the sprayed part with a diameter of 4 - 500 mm to be fixed. Rotation is performed by a mechanical drive with the ability to regulate the rotation speed within 1 - 16 rpm.

Purge system.
A purge system is connected to the capsule, providing for the removal of process gases and the collection of particles of sprayed powders during the spraying process. The system consists of an inertial cyclone, a radial fan and pipes. The radial fan has an outlet for connection to the exhaust ventilation.

Water cooling system.
The water cooling system is designed to supply and drain water required to cool the cathode and current leads of the plasma torch, the plasma spray rectifier and the cyclone included in the purging system.
The system is single-circuit closed based on a chiller, with a booster pump installed on the coolant supply line to the plasma torch.
The water flow through the channels is monitored by liquid flow sensors installed on the drain.

Dispensers.
There are two dispensers on the roof of the capsule. The dispenser consists of a hopper, an electromechanical drive, and a tilt mechanism.
Uniform powder pouring is achieved by using a cascade of cones and changing the diameter of the nozzle of the replaceable cone.
The powder flow rate is determined by the rotation frequency of the electric motor, the amplitude of the oscillation of the tray, changing the position of the dispenser using the tilt mechanism, as well as changing the diameter and the size of the gap to the hopper. Powder pouring from the tray into the receiving hopper is based on the principle of bulk material movement along a horizontal vibrating tray.
From the receiving hopper, the powder is fed by the transport gas into the plasma torch.
The data on the transport gas flow rate are determined by the gas flow sensor and are displayed on the operator panel of the control system. The flow rate of the sprayed powder is measured according to the calibration data depending on the rotation speed of the vibrator motor of the dispenser and is also displayed on the operator panel of the control system.

Platform.
The platform allows servicing the dispensers installed on the roof of the capsule. The collector and booster pump of the water cooling system are also attached to the platform.

Plasma torch for spraying powder materials.
The plasma torch for spraying powder materials is a dismountable structure consisting of a cathode and anode parts separated by an insulator. The plasma jet is generated in the plasma torch as follows. Plasma-forming gas is supplied to the arc chamber, and voltage from the power source is supplied to the water-cooled cathode and anode parts. After the arc gap between the cathode (electrode) and the anode (nozzle) is broken down, an arc is excited, which ionizes the gas passing through the arc chamber of the nozzle, turning it into a plasma jet.

Ramp.
The ramp is used to install two gas cylinders equipped with reducers for adjusting and safely supplying gases to the gas cabinet.

Gas cabinet and control cabinet.
The gas cabinet and control cabinet are designed to ensure uninterrupted operation and control of the technological process performed on the unit.

Electrical wiring.
The electrical wiring is designed to supply power to the plasma spray rectifier, drives, rotator electric motor, sensors, valves. It consists of a busbar, harnesses with electric wires, the necessary protective covers and boxes.

Plasma spray rectifier "VPN-650".
The plasma spray rectifier "VPN-650" is made according to the thyristor rectifier scheme and is designed to power plasma spray units.

Control system.
The automated control system of the plasma spraying unit "UPU-10S" with a plasma torch positioning device includes the following components: a control cabinet, a gas cabinet, a plasma spraying rectifier "VPN-650". The control system of the "UPU-10S" unit ensures automatic entry of the complex into the spraying mode and completion of the process, with registration and documentation of the process parameters.