SGI Prozesstechnik GmbH (Altenstadt, Germany):

Amlinger H., Mag. Eng.
Roth H., Mag. Eng.
Melz B., Mag. Phys.
E-mail (commom): info@sgi-prozesstechnik.com

For final VD, VOD and RH melt treatment, the secondary metallurgy uses vacuum pumps. Vacuum steam ejectors are already known. Some aspects for selection an optimal vacuum pump set are presented here on the examples of pumping equipment at Gieβerei GmbH and voestalpine Stahl GmbH plants in Linz. Construction and operation of three-stage mechanical vacuum pump sets are observed. Energy efficient four- and five-stage mechanical pump sets are up-to-date solutions. The advantages of modular four- and five-stage pump systems, combining high functionality and low energy consumption, are displayed. Requirements for explosion safety in vacuum treatment of steel melt are examined, and operating principle of an explosion-safe pump set is described. General concept of explosion safety is analyzed and responsibility of operators is shown. It is concluded that vacuum pump sets should be protected from increased oxygen concentration and that pump stages have to be resistant to pressure fl uctuations. Ventilation of the machinery hall is also strictly required.

1. Autorenkollektiv: Explosionsschutzregeln mit Beispielsammlung, Explosionsschutz-Regeln (EX-RL) BGR 104. März 2014.
2. Melz, В.: Explosionsschutz, VerlagB. Melz, Königshofen, 1997, ISBN 3-00-000484-X.
3. Redeker, T.; Nabert, K.; Schön, G.: Sicherheitstechnische Kennzahlen brennbarer Gase und Dämpfe. Deutscher Eichverlag. Braunschweig. 1990.