DESIGN AND MANUFACTURE OF ELECTRONIC CONTROL SYSTEMS FOR ALL INDUSTRIAL APPLICATIONS
Technology from Egypt
ENERGY SAVING HEATING SYSTEMS (heating by Induction)
for Industrial Applications
The demand for better quality, safe and less energy consuming heating in the industrial applications is rapidly rising, as heating is required at least in more than one stage during most of the industrial processes.
All metals conduct electricity, while offering resistance to the flow of this electricity. The resistance to this flow of current causes losses in power that show up in the form of heat.
Induction heating is providing alternating electric current at high frequency to an electric coil (the induction coil), The induction coil becomes in this case the heat source that induces an electrical current into the metal part to be heated.
No contact is available between the metal part to be heated and the induction coil as the heat source, because the heat is restricted to localized areas or surface zones immediately adjacent to the coil. This is due to that the alternating current (ac) in an induction coil has an invisible force field (electromagnetic, or flux) around it. When the induction coil is placed next to or around a work piece, the lines of force concentrate in the air gap between the coil and the work piece. The induction coil actually functions as a transformer primary, with the work piece to be heated becoming the transformer secondary (short circuited). The force field surrounding the induction coil induces an equal and opposing electric current in the work piece, with the work piece then heating due to the resistance to the flow of this induced electric current.
The rate of heating of the work piece in this case is dependent on several factors such as the frequency of the induced current, the intensity of the induced current, the specific heat of the material, the magnetic permeability of the material, and the resistance of the material to the flow of current.