Inductive heating is based on the supply of energy by means of electromagnetic induction. A coil, suitably dimensioned, placed close to the metal parts to be heated, with high and medium frequency alternated current flowing through it, induces on these parts parasitic currents whose intensity can be controlled and modulated. The heating occurs without physical contact and only heats the metal parts being treated. The process is characterised as a high efficiency transfer without loss of heat.
The depth of penetration of the generated current is directly correlated to the working frequency of the generator being used; the higher it is, the more the induced currents concentrate on the surface. In this case, the heating homogeneity on a relevant mass, can be obtained only thanks to the principle of thermal conduction which allows the heating to be transferred in depth.
By decreasing the output frequency, it is possible to increase the penetration of the induced currents within the parts. These currents are able to reach the very heart of the mass. The above mentioned phenomenon is connected with the magnetic permeability and endurance of the material under treatment.
The phenomenon of the electromagnetic induction is therefore based on three physical principles:
A) Transfer of energy from the inductor to the mass to be heated, by means of electromagnetic fields.
B) Transformation of the electric energy into heat due to the “Joule effect” The Joule Effect states that the amount of electrical energy is dependent upon the:
The electric current squared, the resistance of the substance through which current is passing and the time the current is in flowing.
C) Transmission of the heat inside the mass by means of thermal conduction
Induction heating is applied in many industries, such as Automotive, IT & Multimedia, Electronics & Solar Cells, Aerospace, Defence and Medical.