Purpose.
The “PAP-3M” plant is intended for hardening and artificial aging of aluminum alloys and tempering of titanium, as well as for other technological processes that require high-quality heating of products in the operating temperature range from 55 to 500 °C.

Design.
The “PAP-3M” unit includes:
- thermal chamber;
- hearth;
- hearth pressing mechanism;
- portal;
- loading mechanism;
- rotary heater drive;
- control system;
- water cooling system;
The furnace body consists of an outer frame and an internal chamber with a screen to obtain a directed air flow. The screen forms a three-way air discharge channel - along the ceiling of the chamber and two sides. Air flow passes through them into the working chamber, and is then sucked into the rotor of the centrifugal fan. The cycle is repeated many times.
The rotary heater drive is a shaft, which is installed in a cast iron housing using bearings. One end of the shaft is attached to rotary heater. The other end of the shaft is connected to the main electric motor by an elastic coupling. The shaft is cooled by water. A frame is designed to mount the rotary heater drive.
Five thermocouples measure the temperature in the working chamber of the plant. Additional thermocouple might be installed on the heated structure.
The main electric motor operates in two modes:
- hardening mode at a temperature of 500 °C,
- artificial aging mode at a temperature of 160 °C.
The temperature in the heating and holding areas in the “PAP-3M” furnace is regulated according to two algorithms:
- changing the cross-sectional area of the suction opening,
- changing the rotor speed.
The rotor power regulator has slotted holes in the housing. During operation, blades block the holes in order to change the cross-section for air suction and the power of the main electric motor. The cross-sections of the air duct change during the heating of the furnace to the rated power of the rotary engine, which is achieved at a temperature of 350-380°C.
The regulator drive is designed to automatically change the cross-section of the holes. The blades close the passage opening of the louvre grille, receiving movement from the regulator drive through the drive rod and transition links.
The space between the chamber body and the frame is filled with heat-insulating slag wool. The frame is covered with flat sheets and cladding panels.
A portal is designed for fastening the thermal chamber, as well as the rails for hauling the hearth and moving the loading device. A hearth pressing mechanism is attached to the portal to create a seal for the loading hole of the thermal chamber. The hearth is used to cover the loading hole.
Loading mechanism is used to load products into the thermal chamber and unload them into the quenching bath. The mechanism consists of a gearbox, brake, electric motor and drums with chains.
The cooling system supplies water to the quenching bath and to the drive housing.

Control system.
The furnace control system consists of a cabinet with electrical equipment and an operator console. The control system allows the furnace to operate in automated and manual modes.