Simultaneous heating process is the process when the workpiece is located in stationary position without any moving. There is two other processing (semi-continuous and continuous) when workpiece can move throughout the technological line. Even in simultaneous processing 2DELTA provides numerous variants to investigate. For example the induction heater has the main induction coil and two additional coils located at the end parts of main coil. These coils may be used to compensate the well known negative “end” effects of workpiece and inductor in the ferromagnetic stage. If you use the additional coils in nonmagnetic stage the distribution of temperature along the surface is very non-uniform due to high specific power at the end parts. In this case the additional coils can be switch off to reduce the overheating of end parts of the load. The example of such variant is presented here.

The first stage has three series connected induction coils to compensate the end effects of inductor and load up to Curie point. In the second no ferromagnetic stage one induction coil is switched on and two other additional coils are switched off to prevent the overheating of end parts of workpiece.

Cooling system is used after second stage for hardening of steel. Inductors 1, 2 and 3 are switched off, cooling system is switched on.