Wondery RT3-380-12 Electric Bogie Hearth Furnace Heat Treatment of Metals Parts (380kW; 1200℃)

Rated power: 380Kw+5% (1-100%) adjustable

Power supply: 380V, 3P, 50Hz

Rated temperature: 1200℃

Control zone: 3 zones

Effective working size: 3500×1600×1600mm (L×W×H)

Heating element connection: Y

Temperature uniformity: ≤ ±10℃

Temperature measurement accuracy: ±2℃

Non-load furnace power consumption: ≤18%

Temperature control method: SCR, PID regulator; Guolong temperature controller with overtemperature alarm;

Furnace surface temperature rise: ＜50℃

Heating element: 0Cr27AL7Mo2 (strip)

Bogie face plate: Ni7N, 30mm thickness, heat resistant steel

Loading method: Product loaded on the bogie, and then bogie moves into the furnace

Furnace door opening method: Electric hoist up-down, sealed by spring

Bogie moving method: By the reducer

Bogie driving power: 4KW

Furnace lining: High temperature Refractory fiber

1. Application

The RT3-380-12 electric bogie heat treat furnace is mainly used for heat treatment of steel structure parts, cast steel parts, shaft bar parts, tool steel products, etc.

2. Structural Introduction

The RT3-380-12 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 wholesale car bottm furnace body steel structure is made

from 8-12# 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 annealing bogie hearth 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

350mm. The silicate aluminum fiber resists a maximum temperature of 1360℃.

The material of round steel fixation parts is 1Cr13.

2.3 furnace door and door up-down system

The tempering car bottom 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 spring.

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 3 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 Ni7N 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 spring. 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 3 heating

zones. All lead-out conductor bars are made of φ16 0Cr27AL7Mo2 material.

2.6 electrical control system

Temperature control: the furnace adopts Shanghai Guolong 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 3 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.