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Iron and steelmaking
ArticleName Explosion safety for steel decarbonizing vacuum units
ArticleAuthor W. Burgmann, U. Zöllig

Vakuum-Metallurgie (Strasbourg, France):

Burgmann W., Dr., Advisor,

Oerlikon Leybold Vacuum GmbH (Cologne, Germany):
Zöllig U., Global Manager, Market Segment Process Industry


Hot gas and steam are forming in the processes of vacuum steel degassing; in combination with oxygen they can form explosive gas mixtures. The paper investigates possibility of originating of such combination and shows the way to reach high level of operational safety via certification of a vacuum unit in correspondence with ATEX 94/9/EC guideline. Additional gas cooling and temperature control between pumps is provided for prevention of possible gas temperature excess. Gas mixes and inflammation possibilities for VOD-processes are presented as examples. The exact composition of gas mixes depends strongly on corresponding control conditions of the technological process. The same tendencies can be observed also for other vacuum degassing processes with decarbonizing (VD-OB, RHO). Composition of waste gases and the moment of forming the gas mixes potentially able for inflammation are quite different in these processes. Therefore, the described ATEX equipment can solve the problems in all cases.

keywords Steel making, vacuum degassing, decarbonizing, gas mixes, explosion safety, waste gases, oxygen, VOD processes, inflammation

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