Energy efficient induction furnaces: practical measures and digital process data

Induction furnaces are ideal for melting all metals in a carbon-neutral way. If the induction furnace is designed as a coreless furnace (Fig. 1), a ceramic crucible is located inside a cylindrical copper coil. The material charged into this crucible is exposed to an electromagnetic field generated by the current flowing through the copper coil. This field induces eddy currents in the metal. The ohmic losses of these eddy currents heat the metal and ultimately liquefy it. Such coreless induction furnaces achieve efficiencies of over 80 % for ferrous materials and over 70 % for highly conductive materials such as copper or aluminum, provided that the coil is made from highly conductive copper and yokes made of transformer sheet laminations are installed to provide a return path for the magnetic field.