Electromagnetic Stirring (EMS) / Induction Edge Heater

• Electromagnetic Stirring Systems

Electromagnetic stirring for Bloom / Billet casters

Generate the force required to move the liquid steel. Indeed, rotative stirrers can easily fit around billet/bloom product. A rotative stirrer acts like the stator of an AC motor fed by a 3-phase electrical current.
The stirrer surrounds the billet/bloom. The liquid steel becomes the rotor of the motor and is put in rotation around its axis in a plane perpendicular to the casting direction.

Electromagnetic stirring for Slab Casters

Linear, also called traveling, electromagnetic stirrers are used on slab casters as their large size would prevent the installation of rotative stirrers surrounding the cast product.
Linear stirrers are fed with 2-phase AC current. They have to be understood as the stator of a motor that has been cut open and uncoiled along the width of the slab. The result is a one-direction force in the slab that moves from one narrow face of the slab to the other.

• Edge Heater

Slab Edge Induction Heating for Hot Strip Mills act as electrical current transformers that generate fixed, transverse magnetic fields. In practice, the primary coils are disposed on a magnetic core that forms a C, with the hot band traveling in the gap. The primary coils are powered with single-phase AC current at medium frequency (300 Hz). The traveling steel bars act as the secondary coil; the eddy currents that are created heat up the steel. The originality of the Danieli-Rotelec-patented design lies in an articulation in the magnetic core that allows adjusting the gap, without magnetic losses, by independent movement of the upper and lower arms.