700℃ Electric Bogie Hearth Furnace 8000×4000×2000mm Annealing Process

8000×4000×2000mm Electric Bogie Hearth Furnace

1. Application

The RT3-900-8 electric bogie hearth furnace is mainly used

for stress relieving annealing process of metal parts.

2.Furnace structure

The RT3-900-8 electric bogie hearth furnace is mainly comprised

for furnace shell, furnace lining, furnace door, door opening and

compression mechanism, bogie and bogie driving mechanism,

sealing system, heating element, circulating device and temperature

control system.

2.1 Furnace shell

The bogie hearth furnace body steel structure is made from 8-14# 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 Furnace lining

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

material used is high quality standard 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 240mm. The silicate aluminum fiber resists a maximum

temperature of 1000℃.

2.3 furnace door, door up-down and sealing system

The car bottom furnace price door is comprised of all-fiber lining and steel

structure casing. The door frame is made of 10mm steel plate. The door is

built with silicate aluminum fiber blocks same as that for the furnace body.

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

The electric hoist is used to drive the furnace door lifting. The seal adopts

the self weight pressing mechanism of furnace door so as to ensure that there

is no inertia during the operation of furnace door, and the sealing is reliable.

A soft contact sealing structure is set between the furnace door and the furnace

lining. When the furnace door is closed, the furnace door is pressed by its own

weight to make the sealing fiber block fully contact with the steel plate and seal.

When the furnace door is opened and closed, the gap between the furnace door

and the furnace door frame steel plate is 50 mm, so as to ensure the stable

movement of the furnace door when opening and closing. The above methods

are simple and practical, reliable sealing and convenient maintenance.

2.4 Bogie and bogie driving mechanism, sealing between furnace body

and bogie

bogie

The car bottom furnace design is comprised of bogie frame, wheels, refractory

bricklaying body, heat resistant bogie face plate and bogie driving mechanism.

The top part of bogie is fire-resistant masonry, max bearing temperature 1000 ℃;

the middle part is the frame; the lower part is the walking mechanism.

Bogie frame: the bogie frame is made from 20# beam. The bogie could work

for a long time without deformation at full load.

Bogie face plate: it is made of CrMnN heat resistant steel. It has long - term use

without deformation and cracking.

Wheel: There are a total of 5 pairs (10 pieces) of wheels, and each wheel is of

diameter 350mm. One pair of driving wheel group and 4 pairs of driven wheel group.

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.

2.5 heating element

heating element: The 0Cr25AL5 resistance spiral-shape alloy resistance strips are

mounted in 5 side walls, two side walls, back wall, furnace door and bogie bottom.

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. There are 6 heating zones. All

lead-out conductor bars are made of φ16 0Cr25AL5 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 car bottom furnace design has 6 temperature control zones 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.

3.Main Technical Parameters