Heavy-duty rectifier systems for graphitizing furnaces.

Where baked carbon is converted to graphite by means of the heating (2600°C – 3300°C) produced by the DC current passing through to the furnace.


In these applications, the DC current typically varies in the range of 70kA to 130kA.
The DC current is supplied to the furnace by the transformer-rectifier units. As the electrical resistance of the furnace decreases with an increasing degree of graphitization, FRIEM controlled rectifiers modulate the DC current and voltage according to process requirements.

FRIEM developed movable transformer-rectifier units that can be moved on rails from a furnace to the next during heat reduction. Movable karts are equipped with pneumatic DC disconnectors for connection to the furnace.
FRIEM’s equipment grants the highest level of robustness, reliability, efficiency and longest lifespan, both in indoor and outdoor installation.
FRIEM’s holds a unique experience and know-how in power electronics, which are essential to support Customers in defining the most effective layout and topology of the power supply aiming at optimizing initial investment’s cost and maximizing production:

  • higher protection degree to withstand the polluted atmosphere and heat that characterize the graphite industry;
  • proved design with regulating transformer, OLTC, saturable reactors and diode rectifiers or thyristor rectifier units;
  • enhanced efficiency through water cooled aluminum buswork for the diode/thyristor high current rectifier.



MOBILITY Knowledge into efficiency


Knowledge into efficiency

SERVICE A partner to our Customer


A partner to our Customer

ENERGY Working now for the future


Working now for the future