Bogie Hearth Quenching Furnace Heat Treatment 1200×1200×600mm Electrical

1200×1200×600mm Electrical Bogie Hearth Quenching Furnace

1. Application

The RT3-75-12 electrical bogie hearth furnace is mainly used for

quenching, structural steel, cast steel, spring steel and tool steel.

2. Structural Introduction

The RT3-75-12 bogie hearth furnace is mainly comprised of furnace

body, lining, furnace door and door compression system, bogie, sealing

mechanism, heating element, temperature control system.

2.1 furnace body

The bogie hearth furnace body steel structure is made from 8-10# sectional

steel and ≥3mm steel plates. The side pillar and back pillars are made from

sectional steel, and are reinforced with sectional steel bracings. The external

wall of the furnace is painted with 2 layers of primers, and 2 layers of

coating paint. The key part of the furnace is painted with heat resistant paint.

2.2 lining

The car bottom furnace supplier is built with an all-fiber system. The lining

material used is quality aluminum fibers fixed by round steel parts. The

aluminum fibers are pre-compressed into blocks (compression gravity:

≥230Kg/m3 ) and then fixed to the furnace body by round stainless steel

parts. This refractory lining structure has the advantages of low heat

conductivity, strong anti-shock capacity, and anti-erosion. The lining has

a total thickness of 350mm. The silicate aluminum fiber resists a maximum

temperature of 1260℃.

2.3 furnace door and door up-down system

The high temperature bogie hearth furnace door is comprised of all-fiber

lining and steel structure casing. The door frame is made of 12mm steel plate.

The lining is built with high aluminum fiber blocks same as that for the furnace

body. The overall structure of the furnace maintains its shape while heated.

Driving method of door: The furnace door is electrically lifted upward and

downward by the electric hoist. And it is sealed by furnace door self-weight.

2.4 bogie and sealing mechanism

The bogie is comprised of bogie frame, wheels, refractory bricklaying body,

heat resistant bogie face plate and bogie driving mechanism.

bogie structure: the bogie frame is made from 12# beam and 12mm steel

plates. The bogie could work for a long time without deformation at full load.

wheel: The wheels are made from ZG55# steel casting. The transmission

shaft is made from 45# steel, and it is heat treated. The transmission bearing

is of the heavy type pillar bearing to bear the weight. There are a total of 4

of wheels, and each wheel is of diameter 240mm.

bricklaying body: The bogie is built with a combination of high alumina

refractory bricks, light refractory bricks, and heat preservation bricks. The

bricklaying body of the bogie has heating elements installation slot for easy

installation of the heating elements. The impacted parts and weight bearing

area are bricked especially with heavy type high aluminum refractory bricks.

There is also free space left for the refractory lining expansion when heated.

The strip shape bogie face plate is cast with ZG35Cr24Ni7SiN, 30mm. The

max temperature≤1200℃. It has long - term use without deformation and

cracking.

Sealing: The seal between furnace door and furnace body and bogie is more

important. The seal between furnace door and furnace body adopts furnace

door self-weight compression structure. The seal between bogie and furnace

body is seal of special-shaped brick, fiber cotton block and sand double seal .

2.5 heating element

heating element: The 0Cr27AL7Mo2 resistance corrugation shape alloy resistance

strips are mounted in two side walls. The resistance strips are produced through

special molds, and are installed in the furnace wall by porcelain nails. And there

is a porcelain gasket between the fiber wall and the resistance strips to avoid

short-circuit. The ceramic screws and gasket are made of high aluminum materials

sintered at high temperature to ensure adequate strength and service life. There

are 1 heating zone. All lead-out conductor bars are made of φ16 0Cr27AL7Mo

material.

2.6 electrical control system

Temperature control: the furnace adopts intelligent temperature controller to control

the temperature which has self-tuning function to calculate the ideal PID parameter

and achieve a temperature stability. The temperature controller has the functions of

over-temperature alarm and thermal couple breakage protection.

The furnace has 1 temperature control zone for controlling the linkage between the

temperature and the motor movements. Each zone is set with an over-temperature

alarm. The heating loop adopts the double-direction SCR and trigger control. The

power is regulated in the time proportional regulation manner.

The control actuation system is a large-power triggering one complete with a

radiator and an air cooling system. There is also an air switch. The heating loop is

equipped with ammeter, voltmeter, heating element on-off indicator, power-on

interlock protection, and safe earthing measures.

Movement control: The control system mainly controls the door up-down movement,

door compression, and door in-out movement. Also the movements are necessarily

linked to ensure the operation safety.

3.Main Technical Parameters