Increase of the energy efficiency of graphite insulated vacuum furnaces

Like in any kind of heat treatment process also in graphite insulated vacuum hardening furnaces not only the heat treated parts with the corresponding loading media but also the heating elements and the complete hot zone are heated up to the necessary process temperature. During this process a large amount of the added energy is lead into the "dead mass" of the hot zone. At the subsequent overpressure gas quenching the heat energy stored in the load as well as in the hot zone is reduced with a high amount of energy again. Vacuum furnaces with innovative hot zone designs like the SCHMETZ system *eSS* need less current due to less "empty losses". Simultaneously shorter heating times are realised. In addition weight optimised gas guiding systems with inflow nozzles also realise a possible higher quenching speed.