3 Types Induction Furnace Working Principle

Induction furnace are industrial furnaces that use the principle of electromagnetic induction to melt metals.

There are three types of AC power used in induction furnaces: 

Power frequency (50 Hz or 60 Hz), 

Intermediate frequency (60-10000 Hz) 

High frequency (higher than 10000 Hz).

Induction furnaces are divided into two types: 

induction melting furnaces and induction heating equipment. 

The former is used for smelting or heat preservation of materials, and the charge is finally in a liquid state; 

The latter is used for heating materials, including overall uniform heating, surface heating or local heating of materials.

Induction furnace working principle

1. The principle of power frequency furnace

The working principle of the power frequency furnace is the specific application of the law of electromagnetic induction, that is, when an alternating current is passed through the induction coil, an alternating magnetic flux is generated. 

This magnetic flux interlinks the metal charge in the crucible, thus causing an induced electromotive force in the charge. Since the charge is a conductor in a closed circuit, a strong induced current is generated under the action of the electromotive force, and due to the surface effect of the current, the strong current flows only along the surface of the charge, generating a large amount of Joule heat, which heats and even melts the charge. .

2. Principle of intermediate frequency furnace

The medium frequency induction furnace is an induction heating equipment for the purpose of heating metal forging or quenching and tempering heat treatment.

The general heating temperature for heating before forging is 1200 degrees, and the heating temperature for quenching and tempering heating is generally within 1000 degrees. 

This kind of intermediate frequency heating application determines that the heating principle of the intermediate frequency heating furnace is only for the purpose of heating and cannot melt the metal. Therefore, the intermediate frequency heating furnace is different from other types of heating furnaces in structure and principle.

3. Principle of high frequency furnace

The high frequency and high current of the high frequency furnace flows to the heating coil (usually made of copper tube) which is wound into a ring or other shape.

As a result, a strong magnetic flux with instantaneous polarity changes is generated in the coil. When a heated object such as a metal is placed in the coil, the magnetic flux will penetrate the entire heated object. In the opposite direction of the heating current inside the heated object, a The corresponding large eddy current. 

Due to the resistance in the heated object, a lot of Joule heat will be generated, and the temperature of the object itself will rise rapidly. To achieve the purpose of heating all metal materials.

The above are the working principles of the three induction furnaces. No matter what kind of induction furnace, we will issue corresponding design drawings, plans, etc. according to the specific requirements of customers, so as to provide customers with a satisfactory product project.

Any questions or needs about the product, please feel free to contact us.

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