1. Application
The RT-210-12 electric bogie hearth furnace is mainly used for heat treatment of steel structure parts, cast steel parts, shaftbar parts, tool steel products, etc.
2. Structural Introduction
The RT-210-12 bogie hearth furnace is mainly comprised of furnace
body, lining, furnace door and door compression system, bogie,
heating element, and temperature control system.
2.1 furnace body
The car bottom 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
Th evertic heat treatment furnace body 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 325mm.
The silicate aluminum fiber resists a maximum temperature of 1260℃. The
material of round steel fixation parts is 1Cr13.
2.3 furnace door and door up-down system
The heat treatment furnace door is comprised of all-fiber lining
and steel structure casing. The door frame is made of 10mm steel plate and
12mm sectional steel. 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.
Driving method of door: The furnace door is electrically lifted upward and downward
by the hoist. And it is sealed by furnace door self-weight.
2.4 bogie
The bogie is comprised of bogie frame, wheels, refractory bricklaying body, heat resistant
bogie face plate, heating elements, and bogie driving mechanism.
bogie structure: the bogie frame is made from 14# 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 2 pairs of wheels, and each wheel is of diameter
300mm. The bogie is motorized. And the driving motor is equipped with a braking speed
reduction device to relieve the inertia at the start-up and stop movement. There are 2 limit
switches to avoid over-travel of the bogie.
bricklaying body: The bogie is built with a heavy 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.
bogie face plate: 30mm thick Cr25Ni20Si2 heat resistant steel casting part with max working
temperature≤1200℃. It can prevent scales from falling into the heating elements slot which
would form a short circuit.
bogie moving mechanism: The bogie has a self-moving method. The reducing gear drives
the bogie wheel to move. The bogie movement is smooth and stable.
Sealing among furnace door, furnace body and bogie: Sealing between the furnace door
and the furnace body is through furnace door self-weight. The sealing between the bogie and
the furnace body is through soft special shape bricks and fiber cotton block.
2.5 heating element
heating element: The 0Cr27AL7Mo2 resistance spiral-shape alloy resistance strips are
mounted in 2 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. There are 2 heating zones.
All lead-out conductor bars are made of φ16 0Cr27AL7Mo2 material.
2.6 electrical control system
Temperature control: the heat treatment 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 2 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.
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.
