1. Purpose. Technological processes used.
The vacuum vertical furnace “PVV-15/25” designed for heat treatment of products made of titanium alloys.
The product is heated in a vacuum to the required temperature, maintained at this temperature and then cooled in a vacuum or in an argon environment. Forced circulation of argon in a closed circuit accelerates the cooling of the product: furnace working space - heat exchanger - ventilation unit - furnace working space.

2. Features of the physical processes.
Chamber heat treatment furnaces are suitable for heat treatment of medium and small parts. They can be used in any type of production and for any processing technology. They can be used as stand-alone pieces of equipment or as part of flexible automated systems.

3. Technical description. Design features. Equipment advantages.
1. Heating chamber,
2. Top lid,
3. Bottom lid,
4. Mechanism for moving the bottom lid,
5. Trestle
6. Rail track
7. Ventilation unit,
8. Vacuum system,
9. Argon inlet system,
10. Pneumatic system,
11. Water cooling system,
12. Electrical wiring,
13. Control system.



The furnace is a cylindrical vacuum heating chamber, which is installed on a trestle. The top and bottom lids cover the camera at the ends. The bottom lid has racks on which guides are installed for loading equipment with the product. The bottom lid together with the cage moves horizontally along the rail track. After this, the moving mechanism lifts the bottom lid with the cage vertically in to chamber. The hydraulic drive system turns the bayonet ring. A bayonet lock locks the chamber while the process is in progress. The top lid is attached to the chamber fixedly.

3.1. Heating chamber.
The cylindrical heating chamber made of stainless steel sheet. Ends of chamber have welded flanges. The chamber has a cooling water-cooled jacket divided into 6 zones. The chamber is equipped with four support plates for installation on a trestle.
A heating sections assembled with a roof are installed inside the chamber. Thin-sheet screen thermal insulation and insulators for heaters are hung on the pins placed inside the chamber. The section contains 6 pieces of molybdenum alloy heaters.
The elastic mechanical seal closes hermetically the connection of heating chamber and lid. The chamber has welded inlets for thermocouples, current leads and the necessary pipelines.

3.2. Top lid.
The top lid is made of two rolled bottoms welded on a flange. The bottoms made of stainless steel. There is a water cooling cavity formed between the bottoms.

3.3. Bottom lid.
As well as top, the bottom lid made of two rolled bottoms. Screen thermal insulation installed on a removable protective screen. The design of the lid has two pairs of wheels driven by a gear motor and is a self-propelled hearth moving along a rail track.
There are supporting surfaces on the four brackets of the movement mechanism to fix the bottom lid.

3.4. Mechanism for moving the bottom lid.
The mechanism for moving the bottom lid loads and unloads the processed products together with the necessary equipment into the heating chamber from and to a position under the chamber. The speed of movement of the lid with the product is 1.1 m/min.

3.6. Ventilation unit.
The ventilation unit designed for forced cooling of the cage with an inert atmosphere. Structurally, the fan is centrifugal with a water-cooled housing.
The rotation of the fan impeller controlled by a frequency electric drive, which allows you to change the circulation speed of the inert atmosphere.

3.7. Vacuum system.
The vacuum system is designed to create a vacuum in the chamber. The system is a set of devices for creating a vacuum and pipelines connecting them through vacuum valves with the pumped-out volume. The system consists of a combined line of fore-vacuum pumping and high vacuum line. Valves installed on steam oil pumps close automatically during a power outage, preventing oil from escaping from the pumps into the pipeline.
The vacuum system has required quantity of sensors to measure medium and high vacuum. The plant has an air preparation unit to do reliable operation of pneumatic valves installed on all lines.

3.8. Argon inlet system
The argon inlet system designed to supply gas into the chamber. The argon inlet system consists of a receiver and a supply pipeline with shut-off valves.

3.9. Pneumatic system.
The pneumatic system controls the pneumatic drives of vacuum valves, as well as supplies compressed air to the hose seal of the heating chamber. The pneumatic system includes an air preparation unit, pneumatic distributions and the necessary supply lines.

3.10. Water cooling system.
The water cooling system supplies and drains water necessary for cooling the furnace and vacuum pumps during the heat treatment process.

3.11. Electrical wiring.
The electrical wiring provides power do supply to the current leads of the heating chamber, transformers, electric motors, pneumatic valves and hydraulic power stations, as well as do ensures the transmission of monitoring and control signals, and consists of a busbar, harnesses with electrical wires, the necessary protective covers and boxes

3.12. Hydraulic drive system.
The hydraulic drive system is a power unit that drives the hydraulic cylinders of the bayonet lock. The hydraulic drive system is turned on and off from the loading console.

3.13. Trestle.
The trestle is intended for servicing the water-cooling system manifolds, gas inlet control panel and power units. The air preparation unit of the pneumatic system mounted on the trestle also.

3.14. Control system.
The furnace is equipped with a two-level control system that ensures the technological process is carried out in service and automatic modes.
A programmable logic controller is used at the lower level of the control system.
The application program provides:
a) in manual mode – the mechanisms and subsystems of the furnace are controlled from the touch screen of an industrial computer to complete the heat treatment cycle in the event of a failure of the automatic mode (located on the front panel of the control panel);
b) in automatic mode - the automatic cycle of operation of the furnace is carried out using application programs, subject to permission from the industrial computer.

The top level is an industrial computer.
The top-level software performs:
a) graphical multi-channel interface with the dispatcher, intelligent support for control functions.
b) displaying the status of the installation’s mechanisms and sensors on the PC screen.
c) indication of the current values of the installation parameters in real time.
d) input and correction of parameters, display of the “history” of parameter values and modes of each technological operation.
e) automatic generation of database records, conversion of the database into the formats of the most commonly used database systems.