1. Your Success is Our Goal www.siemens.com/itps1 www.chemtech.com.br INERTIZATION SYSTEM OF STEEL CASTING WITH PHOENICS IX International PHOENICS Users Conference Moscow, 26 th September 2002

2. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 2 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference Chemtech - A Siemens Company, Rio de Janeiro / RJ – Brazil Flávio Martins de Queiroz Guimarães Bruno de Almeida Barbabela Luiz Eduardo Ganem Rubião CST - Companhia Siderúrgica de Tubarão, Serra / ES – Brazil Henrique S. Furtado Sergio Lopes Mattedi AUTHORS

3. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 3 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference Longitudinal Section Aluminum Oxide Crystals INTRODUCTION – THE PROBLEM Oxidation of the steel surface during casting producing metallic oxides Oxidation of the steel surface during casting producing metallic oxides Obstruction of all discharge pipes Obstruction of all discharge pipes Addition of impurities and reduces process yield Addition of impurities and reduces process yield

4. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 4 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference INTRODUCTION – THE SOLUTION ARGON IN OXYGEN OUT Introduction of inert gases in the casting system to expel the existing atmosphere This process usually makes use of noble gases as argon, which is very expensive to purchase Simulations have been executed to predict the optimal argon inflow, time of inertization and process yield with minimum operational costs of impurities and reduces process yield

5. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 5 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference TUNDISH INTRODUCTION – THE SYSTEM

6. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 6 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference Upper View OUTLETS & INLETS (IN BLUE) THE TUNDISH – GEOMETRY STRUCTURE Frontal View BAFFLES

7. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 7 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference All simulations were run on PHOENICS v3.4. The follow configurations were setting: Total Geometry: 9494 mm x 1543 mm x 1790 mm Total Geometry: 9494 mm x 1543 mm x 1790 mm Grid:  270 000 volume elements (cartesian grid) Grid:  270 000 volume elements (cartesian grid) PARSOL: active PARSOL: active Energy Equation: active Energy Equation: active Turbulence Model: k-  Chen-Kim model (KECHEN) Turbulence Model: k-  Chen-Kim model (KECHEN) Transient Solution: active Transient Solution: active Total Number of Outlets: 3 (three) outlets Total Number of Outlets: 3 (three) outlets Total Number of Injectors: 3 (three) to 8 (eight) injectors Total Number of Injectors: 3 (three) to 8 (eight) injectors Argon Inlet Rate: 250 to 380 Nm 3 /h Argon Inlet Rate: 250 to 380 Nm 3 /h Property models computed by INFORM. Property models computed by INFORM. GENERAL SETTINGS

8. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 8 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference PROPERTIES SETTINGS – SPECIFIC HEAT The following formulae for the pure components were used: Based on the above pure component specific heats, a formula for the mixture specific heat was developed. It was considered in this formulation that the mixture is ideal and that the air has a constant composition (21% O 2 ).

9. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 9 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference PROPERTIES SETTINGS – DENSITY The following formula describe the evaluation of the mixture density. It was considered in this formulation that the mixture is ideal and binary (argon and air only).

10. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 10 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference PROPERTIES SETTINGS – VISCOSITY The following formula describe the evaluation of the mixture viscosity. It was considered in this formulation that the viscosity is independent of the mixture composition. The temperature was computed, despite of the great difference of temperature among the air inside the tundish and argon inlet by nozzles.

11. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 11 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference PROPERTIES SETTINGS – DIFFUSIVITY The following formula describe the evaluation of the mixture diffusivity. It was considered in this formulation that the mixture is ideal and binary (argon and air only).

12. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 12 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference OUTPUT – OXYGEN CONCENTRATION

13. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 13 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FIELD TEST VALIDATION 12345 ARGON NOZZLES BAFFLES OUTLETS 5 (five) sample points have been measured to analyze the dynamic behavior of the process

14. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 14 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FIELD TEST VALIDATION – TURBULENCE Although both models fitted well this data, the k-  Chen-Kim (KECHEN) was chosen because the simulations results have (KECHEN) was chosen because the simulations results have shown that it had a little better mean correlation value and shown that it had a little better mean correlation value and first step result fitted closer to the experimental curve. first step result fitted closer to the experimental curve.

15. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 15 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FIELD TEST VALIDATION – KECHEN MODEL

16. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 16 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FIELD TEST VALIDATION – KECHEN MODEL

17. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 17 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FIELD TEST VALIDATION – KECHEN MODEL

18. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 18 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FIELD TEST VALIDATION – KECHEN MODEL

19. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 19 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FIELD TEST VALIDATION – KECHEN MODEL

20. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 20 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference Time = 2 minutes Time = 3 minutes Time = 1 minute OXYGEN CONCENTRATION

21. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 21 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference Time = 4 minutes Time = 5 minutes OXYGEN CONCENTRATION

22. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 22 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FINAL CASE Several simulations have been performed The injections were relocated in order to avoid stagnation zones The injections were relocated in order to avoid stagnation zones The following figures show the results for the final optimum injection pattern, as currently implemented for daily operation (maximum residual oxygen concentration after 5 minutes of 2.08 %v/v): The following figures show the results for the final optimum injection pattern, as currently implemented for daily operation (maximum residual oxygen concentration after 5 minutes of 2.08 %v/v):

23. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 23 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FINAL CASE – OXYGEN DYNAMIC PROFILE

24. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 24 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference OXYGEN CONCENTRATION AFTER 5 MINUTES FINAL CASE – RESIDUAL OXYGEN PROFILE

25. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 25 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FINAL CASE – OXYGEN PROFILE OXYGEN CONCENTRATION AFTER 5 MINUTES

26. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 26 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference OXYGEN CONCENTRATION AFTER 5 MINUTES FINAL CASE – OXYGEN ISOPLETH

27. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 27 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference CONCLUSION The results showed: Excellent quantitative agreement with field data and good qualitative behavior Excellent quantitative agreement with field data and good qualitative behavior How CFD simulations are becoming even more a very important tool for equipment optimization in the process industries How CFD simulations are becoming even more a very important tool for equipment optimization in the process industries

28. Your Success is Our Goal INERTARGON_IX_IPUC_MOSKOW2002.ppt Slide 28 © IT PS 2002 Steel Casting IX International PHOENICS Users Conference FINAL THANK YOU &QUESTIONS