Transformers Used in the Steel Industry: A Complete Guide
The creation of steel requires very large quantities of electricity. There is no furnace melting scrap and refining molten metal without the help of an industrial transformer that converts electric power supplied from the grid into the desired voltage and current. Without the transformer, the furnace will not work properly, if at all.
It is natural that when speaking about steel production, people mention mainly furnaces, electrodes, and ores. But few realise how much importance this auxiliary component of steelmaking has.
Here we provide you with information about the main types of transformers used at the steelworks and their functions to help you understand why choosing the proper type is very important.
Electric Arc Furnace Transformers
Secondary steelmaking relies on electric arc furnaces. These furnaces heat scrap by creating an electric arc between graphite electrodes and the scrap metal charge. Such a furnace requires transformers capable of producing huge currents at low voltages, as well as being able to withstand highly unpredictable and drastic load changes every time the arc is created or extinguished during heating.
They have special windings made from electrolytic-grade copper wire, robust tap changers, and sophisticated forced-oil cooling systems. They are designed specifically to be able to endure electrical transients which would otherwise destroy ordinary power transformers within just a few hours of their operation.
Submerged Arc Melting Furnace Transformers
In submerged arc furnaces, the electrodes and materials are submerged within the slag bath. The loading is more continuous than that of open-arc furnaces, but the power required is equally huge, sometimes even exceeding 30MVA.Â
They are indispensable for ferroalloy manufacturers as well as for slabs. Long hours of non-stop operation have been considered while designing the transformer. Heat exchangers in OFWF-type coolers help achieve non-stop operation in the system.
Ladle Refining Furnace Transformers
Following the initial melting, molten steel will be transferred into the ladle furnace, where secondary steelmaking occurs. This process refines the steel in terms of its chemistry, temperature, and purity. There will be better stability of the arc in this furnace. This means that the transformer will encounter milder loading conditions.
Accuracy becomes critical at this point. The transformer should supply accurate and stable voltage for even heating. Poor performance of the transformer will affect the final product.
Induction Melting Furnace Transformers
Instead of electric arcs, induction furnaces utilise magnetic fields from coils made up of copper to heat the metal from inside. In such systems, a transformer drives the inverter circuit that operates at medium frequencies (500Hz – 1,000 Hz).
The nature of the loads is more consistent and can be easily predicted. The focus now turns towards efficient design and harmonisation with frequency rather than robustness. Such machines are ideal for foundries and smaller plants.
Power and Distribution Transformers in Steel Plants
Besides the furnace floor area, steel companies require transformers for stepping down the high voltage needed for the whole factory. The distribution transformers will be used to lower the voltage even more for lighting purposes.
In case of a problem with the distribution transformer, the production process can come to a halt, as well as in the case of the furnace transformer. The distribution transformer might not experience the same conditions as the furnace transformer, but it is just as important.
Conclusion
Total reliance is required by the steel industry on transformers. These are used from arc striking to step down voltage from the distribution board in any operation carried out. The ability to identify the appropriate transformer for an intended use is what makes steel manufacturing operations successful and energy-efficient.
None of the transformer types mentioned above is made for universal use; using a general-purpose transformer in place of the specialised one always leads to losses in the end due to increased electricity consumption and faster wear out. Makpowerts is the manufacturer of all kinds of transformers that can be used in steel manufacturing plants, including the Arc Furnace Transformer, Submerged Arc Transformer, Ladle Refining Transformer, and Induction Melting Furnace Transformer.