Electric arc furnace
Process Description
Around 30% of the worldwide production of steel and iron takes place in electric arc furnaces. Many foundries also use electric arc furnaces with tapping weights from 5 to 40 tonnes for the melting of scrap, sponge iron and pig iron. To increase economic efficiency there have been significant developments over the last decade in transformers, panels, furnace geometry, foam slag technology, automation, electrode regulation and hydraulics; and the use of oxygen is state of the art.
An EAF consists of a hearth (a refractory wall forming the lower part of the furnace vessel with an opening for tapping), water-cooled panels and a lid with electrodes and exhaust gas opening.
The oven is loaded with baskets from above by pivoting the lid and the electrodes to the side. Once the lid has been closed and the electrodes inserted, the melting process begins. By means of a light arc between the electrodes and feed material electrical energy is converted into thermal energy.
Example of an electric arc furnace
Oxyfuel-technology supports the process, mainly through replacing electrical energy with chemical combustion energy.
Advantages:
- Savings in electrical energy
- Minimising tap-to-tap times
- Shorter power-on times
- Savings in electrode consumption
- Improvement in foaming slag technology
Example of application
|
Operating data |
|
Minimum |
Maximum |
|
Charge weight |
[t] |
20 |
200 |
|
Tapped weight |
[t] |
17,6 |
162 |
|
Output |
[%] |
78 |
94 |
|
Power on time |
[min] |
15 |
160 |
|
Power off time |
[min] |
6 |
46 |
|
Tap to Tap time |
[min] |
35 |
203 |
|
Electrical energy |
[kWh/t] |
318 |
525 |
|
Oxygen consumption |
[Nm³/t] |
18 |
50 |
|
Natural gas consumption |
[Nm³/t] |
0 |
13 |
|
Total carbon consumption |
[kg/t] |
4 |
31 |
|
FeO in slag |
[%] |
28 |
46 |
|
Electrode consumption |
[kg/t] |
1 |
3,1 |
|
Tapping temperature |
[°C] |
1600 |
1720 |
Gas Application
- Oxygen lance manipulator
- Oxygen burner technology
Messer-Solution
With a cooperation partner, Messer offers a package of a modular design, consisting of oxyfuel burner systems with integrated supersonic oxygen injection and pneumatic coal dust feed, regulation and control of oxygen, fuel and carbon, as well as the entire automation with software.
Oxy-fuel burner system with integrated supersonic oxygen injection
The optimal position, mounted just above the steel bath surface in the area of the foam slag, distributed over the entire cross-section to avoid cold spots and ensure uniform scrap melting, as well as exact knowledge of the process workflows and continuous development of the entire system guarantee benefits to your business.