The vacuum melting furnace "UVPP-120" is designed for the production of castings from heat-resistant nickel-based alloys.

List of components of the furnace "UVPP-120":
Melting chamber;
Sluice chamber;
Retractable block;
Vacuum system;
Water cooling system;
Pneumatic system;
Railway;
Electrical wiring;
Rail track;
Mold lifting mechanism;
Suspended door;
Loading device;
Argon supply system;
Mechanism control cabinet;
Vacuum system control cabinet;
Drive unit 1;
Drive unit 2;
Power cabinet;
Operator console;
Crucible tilt console;
Trolley console 1;
Smelter console;
Capacitor bank;
Thyristor frequency converter of current "TPChT-320".

Design description.
The "UVPP-120" furnace is a design that includes several functional units:
- Melting chamber unit with alloy melting and pouring units located on the sliding block;
- Lock chamber unit with a mechanism for feeding molds for pouring and a vacuum process gate that ensures loading and unloading of poured molds without depressurizing the melting chamber;
- Loading device that ensures loading of the charge into the crucible and measuring the melt temperature in vacuum conditions;
- Vacuum system unit that ensures vacuum in the unit during melting and pouring of metal;
- Water cooling system for the required elements of the unit.

Operating principle.
The charge is loaded into the induction unit located on the sliding block of the melting chamber. The cover of the sliding block closes the melting chamber. The shutter separating the melting chamber from the lock chamber is also closed, ensuring complete tightness of the melting chamber. The process of vacuuming the chamber begins.
The charge melts in the induction furnace after reaching the required vacuum in the melting chamber. Additional charging of the resulting melt can be performed if necessary.
The lifting table with centering is located in the lock chamber. The mold is in a special equipment for transportation - a flask for transporting and pouring molds. The mold is heated to the required temperature, but not higher than 800 C °. The chamber lid is closed and then vacuuming occurs.
The shutter opens after equalizing the pressure in the melting and lock chambers. The mold is fed to the working space of the mold heating furnace for pouring. The temperature in the mold heating furnace at this point is not less than 700 C °.
The mold temperature is brought to the required value, but not more than 1200 °C.

After the metal has melted, the melt temperature is measured. The mold preheating furnace is heated to the required temperature. The mold is raised for pouring. Liquid metal is poured into the mold.
The crucible returns to the vertical position.
The next portion of metal is loaded using a loading device without breaking the vacuum in the melting chamber.
The mold filled with metal is kept in the mold preheating furnace for the required time and lowered back into the airlock. The process vacuum valve is closed.
The atmosphere is released into the airlock by a leak-off valve. The filled mold is removed from the furnace using a shop device. A new mold for pouring is installed in the furnace.
The airlock is closed and evacuated.

The cycle is repeated.

Melting chamber.
The melting chamber is the main element of the installation in which the process of melting metal and pouring it into a hot mold takes place. The operator's workplace is located on the work platform next to the melting chamber. The melting chamber body is welded from steel, external cooling is water. The chamber has a side flange for docking the rollback block, and in the lower part of the chamber there is a flange for feeding the mold for pouring.
The melting and pouring processes occurring in the melting chamber are monitored through two peepholes, for ease of maintenance the peepholes are equipped with manual vacuum shutters, allowing cleaning of the viewing glasses on the peepholes without depressurizing the melting chamber.
A vacuum shutter with a loading device is mounted on the upper flange of the melting chamber.
An explosion-proof valve is also located in the ceiling part of the chamber.
In the bottom of the chamber there is a through hole for feeding molds for pouring. Above this hole there are brackets for installing replaceable PPF. The furnaces have two standard sizes - a furnace with dimensions of the working space up to Ø=800 mm and H=650 mm, and PPF with dimensions up to Ø=800 mm and H=1300 mm. The temperature in the working space of PPF can reach 1200C°.
The furnace has a lid with a hole for installing a drain funnel.

Airlock.
The airlock serves to load and unload heated molds for pouring. In the ceiling of the chamber there is a branch pipe that allows the mold to be fed into the melting chamber for pouring. The airlock is installed under the melting chamber and is separated from it by a vacuum valve with a pneumatic disk-type drive. It consists of a welded body with water-cooled cavities, a system of levers and two pneumatic cylinders operating synchronously.
The airlock cover moves along the beam due to a carriage with four wheels. The movement drive is pneumatic.
The airlock is evacuated with a sealed valve of the vacuum valve and a closed leak-off valve. Vacuuming is performed by two mechanical pumps and a two-rotor Roots pump. A scissor-type lifting mechanism is installed in the lower part of the lock chamber, designed to install heated molds on it and then lift them into the mold heating furnace located in the melting chamber.

The scissor lifting mechanism provides vertical lifting of heated molds weighing up to 650 kg to a height of up to 1900 mm.
The lifting mechanism drive is located on the outside of the lock chamber.

The chamber has a thermocouple sealed lead-in for the possibility of connecting two thermocouples for carrying out temperature measurement of the charge.

Retractable unit.
The retractable unit consists of a welded trolley on which the following are installed:
- a cover with an induction unit (replaceable induction furnaces from 30 to 150 kg) and a crucible rotation mechanism,
- a capacitor bank,
- a converter "TPChT-320".
The cover of the sliding block is a welded rectangular structure with a cooling jacket, the cover is made of corrosion-resistant steel and is installed on the trolley using two posts.
The block cover has a viewing peephole for the lamp, pneumatic clamps are located at the four corners of the cover flange, ensuring reliable fixation of the cover with the flange of the melting chamber.

Rollback block "UVPP-120"

Melting induction furnace (replaceable, with a steel melt weight of 30,60,120,150 kg.) is designed to melt heat-resistant metal and pour it into shell molds.
The working element of the furnaces is an inductor made of a copper pipe. The furnaces have a non-magnetic metal frame. The upper, lower part and side walls of the frame are made of non-metals. Magnetic circuits are located around the induction coil to concentrate magnetic fields.

The crucible rotation mechanism (induction melting furnace) is designed to pour liquid metal from the crucible into hot molds. It consists of a gear motor and a set of gears, as well as flexible water-cooled current leads.

Induction melting furnaces (replaceable - for 30, 60, 120 and 150 kg.) are mounted on a special bracket and connected to a coaxial current lead. Depending on the volume of melted metal, the furnaces have the ability to adjust the drain point due to the longitudinal movement mechanism of the induction furnace. The mechanism ensures the mode of movement of the drain point at the time of pouring the mold.

The coaxial current lead is connected to the capacitor bank using water-cooled flexible current leads.

Vacuum system.
The vacuum system is designed to create a vacuum in the working volumes of the installation:
- melting chamber,
- lock chamber,
- loading device.
The vacuum system is controlled by push-button and partially automatically, such as:
- vacuumization of the airlock,
- vacuumization of the loading device.

Loading device.
The loading device is designed for:
- feeding the melt charge into the melting furnace using process containers;
- ensuring measurement of the temperature of the molten metal in the melting furnace using a pyrometer and a quick-release immersion thermocouple.
The loading device consists of a welded box-type body and a flat metal door.
A pyrometer is mounted on the upper flange of the loading device for continuous measurement of the temperature of the molten metal.
The loading device is mounted with its lower flange on the melting chamber through a flat pneumatic vacuum valve, and is connected to the vacuum system with its side flange.
The body of the loading device contains two hollow rods, one carrying the loading cup, the other - the immersion thermocouple. Each rod has an autonomous electromechanical drive, which ensures independent sequential loading of metal into the crucible and measurement of the melt temperature without de-vacuuming the loading device.

Water cooling system.
The water cooling system is designed to cool the elements of the installation that operate in the high-temperature zone or create high temperatures during operation. The system consists of pressure and drain collectors located on the service platforms, as well as a circulating cooling system consisting of a frame with heat exchangers and pumps and a tank for distilled water.
All collectors and pipelines of the cooling system are made of corrosion-resistant materials.

Pneumatic system.
The pneumatic system consists of pneumatic equipment - pneumatic cylinders, pneumatic valves, etc., controlling the devices and units of the installation.

Coaxial current lead.
The coaxial current lead is designed to transmit electric power from the power source to the melting inductor through flexible current leads. The assembled current lead is mounted on the cover of the rollback block in the induction block movement unit. The coaxial current lead is rotated from the crucible rotation mechanism through a gear transmission.

Mechanism for moving the melting furnaces.
The mechanism for moving the melting furnaces is located on the cover of the rollback block. The mechanism provides adjustment of the metal drain trajectory when using different melting blocks - from 30 to 150 kg. The travel of the induction blocks is 300 mm.

Rail track.
The rail track is designed for moving a trolley along it, carrying a rollback block.
The track consists of channels, a profile pipe and plates to which the guides are attached. The track has trolley travel limiters and limit switches.

Inspection windows.
Inspection windows are designed to monitor the position of the mold heating furnace located under the pouring, the state of the molten metal in the crucible during temperature measurements and when pouring the metal into the mold. For ease of cleaning, the inspection windows are cut off from the total vacuum volume by manual vacuum valves.