Bar heating furnace

Introduce:For the heating furnace of round bar, round steel, square steel and steel plate, how to choose and choose the bar heating furnace? How to calculate the power of the bar heater? What parameters are required for the selection of bar heating furnaces? How to choose the power frequency of the bar heater? the method of selecting the efficiency of the bar heating furnace. 
  • Introduction
  • Consultation

The complete set of automatic bar heating furnace consists of: intermediate frequency power supply, capacitor cabinet, sensor, automatic feeding rack, unloading rack and control cabinet. The intermediate frequency power supply adopts a split structure design, and the power cabinet is a GGD standard cabinet. The capacitive cabinet and inductor are compact in design and increase heating efficiency.

Reasonable control of the distance between the sensor and the heating rod shortens the time for the red hot rod to be exposed to the air, reduces the scale of the round rod , and reduces energy consumption. The speed of the transmission mechanism is automatically controlled according to the process parameters set by the user. When there is no workpiece in the sensor, the automatic control system automatically reduces the output power of the intermediate frequency power supply; the workpiece enters the sensor, and the automatic control system automatically increases the output power of the intermediate frequency power supply.

First, the summary of technical parameters of bar heating furnace

Round rod diameter

Round bar length

Heating temperature

Furnace power

Φ16mm

300mm

1100

250kw/4000HZ

Φ31-80mm

70-480mm

1250

500kw/2500HZ

Φ120mm

1500mm

1250

2000kw/1000HZ

The medium frequency induction heating furnace can be customized according to actual needs.

 IMG_20180510_100155.jpg

Bar heating furnace application assembly drawing

Second, the application of bar heating furnace:

Forging heating: used for round bar, round steel, square steel, steel plate heating, temperature compensation, blue quenching material online heating, local heating, metal material online forging (such as gears, semi-shaft connecting rods, bearings, etc.) , extrusion, hot rolling, heating before shearing, spray heating, thermal assembly, and heating, annealing, tempering, etc. of the entire metal material.

Heat treatment: mainly for shafts (straight shaft, variable diameter shaft, camshaft, crankshaft, gear shaft, etc.); gears; sleeves, rings, discs; machine tool screws; guide rails; planes; ball heads; hardware tools, etc. Surface heat treatment of mechanical (automobile, motorcycle) parts and overall quenching, annealing, tempering of metal materials.

Third, what parameters are required for the selection of bar heating furnaces?

The selection of bar heating furnace generally requires the following parameters:

First: the shape of the heated workpiece, the outer dimensions, and the weight of the heated workpiece.

Second: the material quality of the heated workpiece (generally induction heating, only for metal conductor materials).

Third: the time of the target temperature required for heating the heated workpiece, and the target temperature.

Once the above three points are clear, the bar heating furnace can be selected including matching power.

Fourth, what are the characteristics of the bar furnace heating furnace structure?

1. Furnace structure: Our company's heating furnace is designed as an overall quick change type. Quick change is possible when changing the furnace body for different heated workpieces.

2. Furnace lining: The lining is made of silicon carbide or integral knotting, and the temperature is above 1450 °C.

3. Protection: Automatic shutdown when the water temperature exceeds 65 °C.

4. Induction furnace water cooling rail: Water-cooled rail is installed on the induction furnace lining.

Fifth, how to calculate the power of the bar heater?

P=(0.168×200×693)/(0.24×0.6×145)=1029KW In the formula: 0.168—the average specific heat of the ferrous metal; 2080—the mass of the workpiece (Kg); 200—the temperature rise of the workpiece heating; 0.24— Work heat equivalent; 0.6 - average efficiency (0.6 in this case, generally 0.5 ~ 0.65, lower profile sensor, take 0.4); 145 - work beat (seconds)

According to the above calculation, a 1KHz induction heating device with a rated power of 1500 KW can be configured to meet the needs.

Sixth, how to choose the power frequency of the bar heating furnace?

The choice of power frequency follows the principle of optimal heating efficiency and temperature uniformity (core temperature difference). The higher the frequency, the higher the heating efficiency, but the too high frequency is likely to cause the surface of the workpiece to be too burnt. According to our experience, the frequency is selected to be 2500KHZ. , the best heating effect can be obtained without overheating the workpiece temperature.

Seven, how to choose and choose a bar heating furnace? Mainly from several aspects:

1. Shape and size of the heated workpiece

For large workpieces, round bars and solid materials, bar heating furnaces with relatively high power and low frequency should be used; for small workpieces, tubes, sheets, gears, etc., rod furnaces with low relative power and high frequency are used.

2. Depth and area required for heating

The heating depth is deep, the area is large, and the whole heating should be selected. The bar heating furnace with high power and low frequency should be selected; the heating depth is shallow, the area is small, local heating, and the bar heating furnace with relatively low power and high frequency is selected.

3, the required heating rate

The required heating speed is fast, and a bar heating furnace with relatively large power and relatively high frequency should be selected.

4, the continuous working time of the equipment

The continuous working time is long, and the bar heating furnace with a slightly larger power is used.

5, the connection distance between the sensing component and the device

The connection length is long, and even the use of water-cooled cable connection is required. The medium-frequency induction heating furnace with higher power should be used relatively.

6, process requirements

In general, quenching, welding and other processes, relatively power can be selected smaller, frequency selection is higher; annealing, tempering and other processes, relative power selection is larger, frequency selection is lower; red punch, hot calcination, smelting, etc., need For a heating process, the power should be chosen to be larger and the frequency selected lower.

7, the material of the workpiece

The relative power of the high melting point of the metal material is larger, the relative power of the lower melting point is smaller; the power of the smaller resistivity is larger, and the power of the larger resistivity is smaller.

Eight, the bar heating furnace has significant advantages:

1. Compared with traditional heating means (oil, coal, gas), it has the remarkable advantages of environmental protection, energy saving, convenient operation and low labor intensity;

2. Compared with the thyristor intermediate frequency, the energy saving is 10%~30%, and there is no harmonic interference to the power grid;

3. Compared with the resistance furnace, the energy saving is 50%~60%;

4. It has the advantages of fast heating, uniform heating, no oxide layer and good product quality for customers' products;

5. The sensor is isolated by a transformer and is very safe.

6. Environmental protection: no pollution, noise and dust.

7. Adaptability: It can heat various workpieces with different shapes.

8, the equipment occupies a small area, less than two square meters, to facilitate customers to maximize the use of production space.

Nine, why is the bar heating furnace efficient?

The principle of the bar heating furnace is electromagnetic induction, and the heat is generated in the workpiece itself. The ordinary worker can carry out the continuous work of the forging task ten minutes after the bar furnace heating work, without the need for the professional workers to burn and seal the furnace in advance.

 Work. Don't worry about the waste of the heated billet of the coal stove caused

 by power outage or equipment failure. Because the heating method has a fast heating

 rate, there is very little oxidation, and at least 20% of the forgings and the coal

 burning furnace save the steel material. 50 kg, the material utilization rate can

 reach 95%. Because the heating method is evenly heated, the core surface temperature

difference is very small, so the forging die also greatly increases the life of the

forging die, and the surface roughness of the forging piece is also less than 50um.

 Heating its heat in the workpiece itself, so heating evenly, the core surface

temperature difference is very small. The application of temperature control system

can achieve precise control of temperature to improve product quality and pass rate.

 


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