1. Purpose. Technological processes.
The “PVV-1300/900” plant intended for carrying out technological heat treatment operations - annealing, hardening, aging, tempering.

2. Features of the physical processes used.
The operation of the furnace is to heat the workpiece in a vacuum to a certain temperature and carry out heat treatment of the parts with accelerated cooling by a flow of argon.

3. Technical description. Design features. Equipment advantages.

3.1. Main components:
The plant “PVV-1300/900” consists of the units:
- Vacuum chamber;
- Vacuum system;
- Water-cooling system;
- Gas injection system;
- Pneumatic system;
- Control system;
- Electrical wiring.

3.2. Construction.
3.2.1. Vacuum chamber
“PVV-1300/900” furnace made in the form of a horizontal vacuum heating chamber of a cylindrical shape. On the front end the chamber has a door which closes manually and presses with a bayonet lock. On the rear side the chamber is closed with a rear lid which is attached to the camera with pins.
The chamber is installed on the foundation and secured with anchor bolts. The heating chamber contains a heating module with band heaters made of molybdenum and screen thermal insulation made of seven layers of stainless and heat-resistant steel.
At the bottom of the heating module there are supports on which the cage is loaded using a stacker.
The heating chamber has pipes for connecting the vacuum system.
The chamber made of sheet stainless steel. Flanges are welded to the ends of the cylinder for attaching the rear cover and securing the door.
The chamber has a water-cooling jacket.
For mounting thermocouples, vacuum sensors, and current leads, pipes are welded into the chamber. Cooled current leads are installed on top of the chamber, and thermocouples are installed on the side of the chamber.
The door and rear cover are elliptical shape and made of stainless steel with a water cooling jacket.
Heat exchangers, screens and a damper are mounted on the inner rear lid. The screens are made of stainless, heat-resistant alloy. An electric drive controls the dumper..
A fan is attached to the rear lid to cool the cage with a gas flow.
Screen protection is attached to the door inside.
The door is designed for loading cages. The door is pressed mechanically with a bayonet lock using an electric drive.

3.2.2. Vacuum system
The vacuum system is designed to create a vacuum in the chamber volume.
- The system consists of a fore-vacuum pumping line and a high-vacuum pumping line.
- Forevacuum pumping is created by Roots spool pumps. The line is equipped with pneumatic valves to provide control of the system, as well as a valve that closes automatically when the pump is turned off, which prevents the release of oil from the pump into the pipeline.
- The diffusion pumping line consists of a rotary vane, Roots and diffusion pump. The necessary sensors are available to measure vacuum.
- All valves and gates of vacuum system are pneumatically actuated.

3.2.3. Water-cooling system
The water-cooling system serves to supply and drain water necessary for cooling the vacuum system pumps, heat exchangers, heating chamber, door, rear lid and current leads during the process operation.
The water-cooling system is divided into two circuits and consists of two pressure and drain collectors. One circuit is intended for cooling the vacuum system, the other for cooling the jackets, lid bottoms, current leads, and chambers. A circulating water-cooling system with collapsible heat exchangers, network pumps and a cooling tower was used. The water flow through the channels is controlled by water control units (WCU) complete with liquid flow sensors (FS), which monitor the water flow at the drain. An alarm signal is issued when there is no water at the drain,.
- Water-cooled elements are designed for a maximum water pressure of 0.4 MPa (4 kgf/cm2) and a minimum of 0.25 MPa (2.5 kgf/cm2).

3.2.4. Gas injection system
The inert gas (argon) injection system is designed for accelerated cooling of the charge. The argon inlet system consists of a ramp for installing gas cylinders and a supply pipeline with shut-off valves. The valve controls the argon flow while supply.
3.2.5. Pneumatic system
The pneumatic system controls the pneumatic drives of vacuum valves and mechanisms. The pneumatic system includes an air preparation unit, a filter, pneumatic distributor panels and pipelines.

3.2.6. Control system
The plant is controlled from the front panels:
- power cabinet;
- control cabinet;
- operator console;
- control panel.
The controls for the vacuum system and mechanisms are located on a mimic diagram located on the front panel of the control cabinet. Heating controls mounted on the front panel of the operator console.
Equipping of the plant with a two-level control system ensures the technological process to be carried out in setup, manual, and automated modes.
A programmable logical controller is used in the lower level of the control system.
The application program provides:
a) in adjustment mode - control of mechanisms and devices of plant subsystems (vacuum, heating, movement of mechanisms) to perform adjustment, repair and maintenance work;
b) in manual mode – the heating control when the automated mode failure.
c) in automated mode – the automated cycle of operation of the plant.
The top level is an industrial computer (PC).
Top-level software provides a graphical multi-window interface, intelligent support for control functions:
a) displaying the status of mechanisms and sensors on the PC screen;
b) indication of current installation parameters in real time;
c) input and correction of parameters, display of the “history” of installation parameter values;
d) automatic generation of database records, conversion of the generated database into the formats of the most commonly used database systems;
e) fast passage in forward and reverse directions.
A programmable logic controller (PLC) collects and processes information from temperature and position sensors. Each controlled parameter at the stage of its determination is subjected to standard mathematical processing, which includes: scaling of measured signals, control of the reliability of logical analysis of the values of interrelated parameters, rejection of false measurements, control of violation of the specified measurement range.

3.2.7. Electrical wiring
The electrical wiring provides the power supply to the heaters from the transformer and provides the power to the control circuits of the mechanisms of units with electric drives. Electrical wiring has a busbar, harnesses, protective covers and boxes in which the wires are laid.
The electrical wiring according to the connection diagram is respectively connected to the power cabinet, control cabinet, control panel, control panel.

3.3. Equipment advantages.
- The use of modern heat-resistant materials makes it possible to maintain a stable heat treatment temperature of up to 1350 °C;
- Gas injection system makes the accelerated cooling of the cage;
- The control system has the ability to operate in three modes: adjustment, manual and automated.