Difference between Induction Furnace and Electric Arc Furnace

A furnace is an equipment used to produce heat for a specific purpose. Hence, it is also called heating furnace, as its main function is to generate heat. The heating furnaces are used in various applications such as heat treatment, melting and smelting, ceramic industries, glass production, and many other industrial jobs. The heating furnaces provide a best way of producing high-temperature heat in a controlled manner. Depending on the principle of operation, the heating furnaces can be classified in various types such as electric arc furnace, induction furnace, blast furnace, gas furnace, and more.

In this article, we will explore details and differences of induction furnace and electric arc furnace. The primary difference between induction furnace and electric arc furnace is in their heating principle i.e., an induction furnace generates heat through electromagnetic induction, whereas an electric arc furnace produces heat by creating an electric arc between two electrodes. However, both types of heating furnaces utilize electricity as the source of energy.

Let us get a detailed overview of induction furnace and electric arc furnace.

What is an Induction Furnace?

An induction furnace is a type of electric furnace used to produce heat for melting metals and performing other industrial processes.

The principle behind the generation of heat in an induction furnace is the electromagnetic induction. According to this principle, a changing magnetic field induces an electric current in the body of the metal to be heated.

Let us understand how does an induction furnace works.

An induction furnace consists of an electromagnetic coil made up copper wire wound around the core or crucible of the furnace.

When an alternating current is made to flow in the coil, a changing magnetic field is produced around the coil.

Now, the charge or metal to be heated is placed in the furnace crucible. Thus, the metal is subjected to the changing magnetic field. This changing magnetic field induces circulating electric currents (eddy currents) within the body of the metal charge through electromagnetic induction.

Since, the metal charge has certain electric resistance, the induced eddy currents generate heat within the body of the metal due to resistive effect. This way an induction furnace is used for producing heat.

These days, industries prefer to use induction furnaces over other types of electric furnaces due to the following advantages −

• Higher efficiency due to direct heating.

• Clean and safe working environment.

• Quick and controlled heating.

• Less risk of material contamination due to no direct contact between heating source and charge.

• High versatility and suitability for wide range of metals.

• Low maintenance cost, etc.

Hence, the induction furnaces are widely used in several industries from steel production to metal casting and heat treatment.

What is an Electric Arc Furnace?

An electric arc furnace is another type of electric furnace used in industries to produce heat for melting and production of steel and other metals.

The principle of heat production in an electric arc furnace is based on the creation of a high-temperature electric arc.

A typical electric arc furnace consists two electrodes made up of graphite. When an electric current is passed through these electrodes, a high temperature electric arc is created in the gap between the electrodes. The temperature of the electric arc is above 3000 °C.

This high-temperature heat then melts the material placed in the furnace crucible.

The electric arc furnaces also have the following major benefits −

• High versatility and flexibility.

• Environment friendly heat production.

• High energy efficiency than conventional heating furnaces.

• Low initial cost, etc.

The electric arc furnaces are widely used in scrap industries and steel production applications.

This is all about basics of induction furnace and electric arc furnace. Let us now discuss the major differences between these two types of electric furnaces.

Difference between Induction Furnace and Electric Arc Furnace

The following table highlights all the key differences between induction furnace and electric arc furnace −

Parameter	Induction Furnace	Electric Arc Furnace
Principle	Induction furnaces produce high-temperature heat according to the principle of electromagnetic induction.	Electric arc furnaces produce heat by creating a high-temperature electric arc.
Energy efficiency	Induction furnaces have higher energy efficiency.	Electric arc furnaces are relatively less energy efficient than induction furnaces.
Operating temperature	Induction furnaces operate at relatively lower temperatures.	Electric arc furnaces operate at much higher temperatures.
Size	Induction furnaces are relatively smaller in size.	Electric arc furnaces have large size.
Suitability	Induction furnaces are best suited for small-scale operations.	Electric arc furnaces are suitable for heavy-duty and large-scale operations.
Noise	Induction furnaces produce very low noise.	Electric arc furnaces produce very high noise due to production of electric arc.
Initial cost	Induction furnaces have lower initial capital cost.	Electric arc furnaces have higher initial capital cost than induction furnaces.
Maintenance cost	Induction furnaces have higher maintenance cost.	Electric arc furnaces have lower maintenance cost.
Oxidation losses	In induction furnaces, the oxidation losses are very low.	In electric arc furnaces, the oxidation losses are high.
Electrode cost	Induction furnaces do not have electrodes, hence there is no electrode cost.	Electric arc furnaces involve electrode cost that is significantly high.
Energy consumption	Induction furnaces consume more electrical energy per ton due to low power factor.	Electric arc furnaces consume less electrical energy.
Impact on environment	Induction furnaces have relatively lower impacts on environment due to high energy efficiency.	Electric arc furnaces have more impacts on environment due to lower efficiency and high emissions.
Melting capacity	Induction furnaces have lower melting capacity.	Electric arc furnaces have higher melting capacity than induction furnaces.
Temperature control	Induction furnaces provide precise temperature control.	Electric arc furnaces do not provide temperature control like induction furnaces.
Applications	Induction furnaces are used for melting various non-ferrous metals like copper, aluminum, etc.	Electric arc furnaces are mainly used in iron and steel production and for melting scrap.

Conclusion

In conclusion, the induction and electric arc furnaces are widely used types of electric furnaces in various metal industries. Both furnaces work on electricity to produce heat. Also, the induction and electric arc furnaces have higher energy efficiency than other conventional types of heating furnaces. However, they are completely different from each other in several aspects as explained in the above comparison table. The most significant difference between induction and electric arc furnaces is that an induction furnace generates heat through electromagnetic induction, while an electric arc furnace generates heat through an electric arc created between two electrodes.