SMS Siemag AG (Düsseldorf, Germany):

Odenthal H.-J., Dr. Eng., Prof., Head of Dept. of Technical Researches for Grounds and Simulation of Melting and Reduction, e-mail: hans-juergen.odenthal@sma-siemag.com
Schlüter J., Mag. Eng., Head of Special Development

AG der Dillinger Hüttenwerke (Dillingen, Germany):

Lachmund H., Dr. Eng., Head of Research and Development of Steelmaking
Bruckhaus R., Dr. Eng., Head of Steelmaking Plant

Basic oxygen process can be improved even today — meaning efficiency rise of blowing-in of oxygen and inert gas, increase of productivity and save of expenses. Three examples will be used to demonstrate how the BOF process can be improved. Thanks to a new calibration method for the BOF blowing lance, a quick check can be performed to find out whether the supersonic nozzles are operated at the design point. A self-adapting adjustment unit is presented which is installed in the lance tip, reacts to pressure changes in the oxygen and controls the area ratio between nozzle throat and outlet cross section. With this prototype, which is currently still being developed, the blowing lance can be operated at the design point with an extended range of flowrates. The calibration and adjustment units serve the objective of increasing the nozzle‘s service life, improving the efficiency of the oxygen jet and making the blowing process more reproducible. Furthermore, a BOF bottom stirring strategy is presented. This method is based on uniting of separate blowing units in the groups and varied lowering of gas feed with definite time intervals (i.e. with redistribution of flows). Blowing with inert gas is considered to be the best and is determined using preliminary simulation via calculative hydrodynamics CFD with correction of corresponding CFD model. Thanks to the alternating activation of stirrers, which are combined in groups, up to 30% of inert gas can be saved while achieving identical metallurgical results.

1. Anderson, J. D.: Modern compressible flow, 3. Aufl ., McGraw-Hill Series, New York, 2004.
2. Odenthal, H.-J.; Emling, W.H.; Kempken, J.; Schlüter, J.: Iron Steel Tech. 4 (2007) Nr. 11, S. 71/89.
3. Klioutchnikov, I.; Olivier, H.; Odenthal, H.-J.: Coaxial jets entering into a hot environment, 29^th Intern. Sympos. on Shock Waves (ISSW29), Madison, USA, 14.–19. Juli 2013.
4. Odenthal, H.-J.; Bui, P.; Reiff erscheid, M.; Hovestädt, E.; Nies, J.; Klioutchnikov, I.; Olivier, H.: Advanced design of injection/burner systems in electric arc furnaces (EAF), Proc. 4. Intern. Conf. on Modelling and Simulation of Metallurgical Processes in Steelmaking, Düsseldorf, 27. Juni — 1. Juli 2011, S. 1/12.
5. Bruckhaus, R.; Lachmund, H.: Stirring strategies to meet highest metallurgical requirements in the BOF process, Proc. AIST 2007, 7.– 10. Mai 2007, Indianapolis, USA, S. 1/8.
6. Ansys Fluent, User´s Guide, 2008.
7. Wuppermann, C.; Pfeifer. H.; Odenthal, H.-J.; Jipnang, E.; Hovestädt, E.; Schlüter, J.: stahl u. eisen 132 (2012) Nr. 6, S. 39/50.
8. Menter, F. R.; Egorov, Y.: Turbulence modeling of aerodynamic flows, Proc. Intern. Aerospace CFD Conf., Paris, Frankreich, 18.–19. Juni 2007, S. 1/17.
9. Bothe, D.; Stemich, C.; Warnecke, H.-J.: Chemie Ing. Tech. 76 (2004) Nr. 10, S. 1480.