380V 3P 50HZ Bogie Hearth Furnace With Siemens S7-200 PLC Control
1. Application
The gas and electrical combined bogie hearth furnace is mainly used
for heat treatment of metal parts.
2. Main Technical Parameters
| No. | Item | Technical Parameters |
| 1 | Rated power | 250kW+5% (1-100%) adjustable |
| 2 | Power supply | 380V,3P,50Hz |
| 3 | Rated temperature | 1150℃ |
| 4 | Empty furnace temperature rising speed | ≤2.5h to receive 950℃ |
| 5 | Control zone | 2 zones for temperature and 2 other points for measuring the
temperature, 4 thermal couples in total |
| 6 | Effective working size | 2500×1500×1500mm (L*W*H) |
| 7 | Heating element connection | Ｙ |
| 8 | Temperature uniformity | ±5℃ |
| 9 | Instrument control accuracy | ±2℃ |
| 10 | Empty furnace power consumption | ≤18% |
| 11 | Temperature control method | SCR, PID regulator, Shimaden temperature controller,
over-temperature alarm |
| 12 | furnace surface temperature rise | ＜45℃+ room temperature |
| 13 | Heating element material | 0Cr27AL7Mo2 (strip) 5-wall heating |
| 14 | Bogie face plate | Cr25Ni20 |
| 15 | Loading method | Product loaded on the bogie, and then bogie moves into the furnace |
| 16 | Furnace lining | High temperature refractory fiber structure |
| 17 | Furnace door opening method | Electrical up-down, spring compression sealing structure |
| 18 | Bogie in/out method | 2.2KW cycloidal pin wheel reducer |
3. Structural Introduction
The bogie hearth furnace is mainly comprised of furnace body,
lining, furnace door and door up-down system, bogie,
heating element, and temperature control system.
3.1 furnace body
The furnace body steel structure of bogie hearth furnace is made
from 10-12mm sectional steel and 4mm 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.
3.2 lining
The lining material used is quality high 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 stainless steel parts.
This refractory
lining structure has the advantages of low heat conductivity,
strong anti-shock capacity, and anti-erosion. The lining layer
total thickness is 350mm.
The silicate aluminum fiber resists a maximum temperature of 1250℃.
The round steel fixation parts are made of 304 material.
3.3 furnace door and door up-down system
The furnace door is comprised of all-fiber lining and steel
structure shell. The furnace body is made of 10mm steel plate and
10mm sectional steel. The door is built with silicate aluminum
fiber blocks same as that for the furnace body. The fiber blocks
are fixed by stainless steel parts. The overall structure of the
furnace maintains its shape while heated. The door edge is made of
10mm thick steel.
Driving method of door: The bogie hearth furnace door is
electrically lifted up or down by the electric hoist, and the door
is sealed by the
spring compression mechanism. The use of the electric hoist removes
the need of a foundation pit.
Sealing structure: The door sides are sealed together with the
furnace body through the fiber blocks, and the fiber block is
compressed by the spring to ensure a firm sealing between the door
and the body.
3.4 bogie
The bogie is comprised of bogie frame, wheels, refractory
bricklaying body, Cr25Ni20 heat resistant bogie face plate,
heating elements, and bogie driving mechanism.
bogie structure: the bogie frame is made from 14# beam and 10mm
steel plates.
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 3 pairs of Ø300 wheels to support the
weight of the parts.
bricklaying body: The bogie is built with a combination of high
aluminum 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 Cr25Ni20 heat resistant steel casting
part with 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
bogie and the furnace body is through
deformed bricks and fiber blocks.
3.5 heating element
heating element: The 0Cr27AL7Mo2 resistance spiral-shape alloy
resistance strips are mounted in the 2 side walls and the bogie.
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.
3.6 temperature control system
Temperature control: the furnace adopts Shimaden intelligent
temperature controller (Japan brand) to control the temperature
which has self-tuning function to calculate the ideal PID parameter
and achieve a temperature stability.
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. When the furnace
works, the heating loop works according to the set program
of the temperature controller.
The control actuation system of the car bottom furnace is a
large-power triggering one complete with a radiator and an air
cooling system.
The heating loop is equipped with ammeter, voltmeter, heating
element on-off indicator, power-on interlock protection, and safe
earthing measures.
4. Supply Scope of Bogie Hearth Furnace
| No. | Item | Q’ty | Notes |
| 1 | Furnace body | 1 set | |
| 2 | Bogie | 1 set | Including bogie face plate |
| 3 | Electrical driving system | 2 sets | 1 set for bogie and 1 set for door |
| 4 | Heating element | 1 set | Resistance strip |
| 5 | Temperature control system | 1 set | |
| 6 | Control cabinet | 1pc | 1800×800×600mm |
| 7 | Temperature controller | 4pcs | |
| 8 | SSR | 2Sets | |
| 9 | Wire collet | Several | According to the wiring post number |
| 10 | Compensation lead wire | 60m | |
| 11 | Thermal couple | 4 pcs | 0-1200 degree celcius |
| 12 | Electrical components | 1 set | SCR, air switch, ammeter, voltmeter, heat relay, and switches |
5. Main Components List
| No. | Item | Origin |
| 1 | Temperature controller | Shimaden, Japan |
| 2 | SSR | Shimaden, Japan |
| 3 | Resistance strip | Shougang, Beijing |
| 4 | Refractory fiber | Morgan |
| 5 | Refractory brick | Morgan |
| 6 | Reducer | ABB |
| 7 | Low voltage components | Schneider |
| 8 | Bogie face plate | Xinghua, Taizhou |
Picture of PLC control for Electric Resistance Bogie Hearth Furnace
