Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

1. Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2 J.R. McDermid, Noranda Inc. - Technology B.M. Maag, Pro-Tec Coating Co. M. Gaug, Maya Heat Transfer Technologies 94th Galvanizer’s Association Meeting Dearborn, MI

2. Outline • Introduction • Numerical Model Details • Results and Discussion • General Observations • Detailed Case Results • Conclusions McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

3. Introduction • Numerical and physical modelling has evolved to become a powerful tool for understanding the factors which control and can alter flow in the CGL bath • many papers presented on this subject at the GA, Galvatech and other conferences • Solutions now encompass the coupled thermally driven (buoyancy) flow as well as the strip-driven viscous drag flow • significant effect of ingot melting on the flow field in the charging area McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

4. Introduction - cont’d • Some practical applications of numerical modelling without the thermal solution have been published • snout flow - references 9 and 11 • dross management - reference 12 • Objective of the present work: • Use coupled thermal solution to determine the effect of different charging configurations on the flow field in the Pro-Tec CGL2 bath • Use these results to aid in the selection/specification of a new ingot charger by Pro-Tec McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

5. Numerical Modelling Procedure • Model consisted of a half-bath with a symmetry plane along the long axis of the CGL bath • Model meshing and calculation were performed at Maya Heat Transfer Technologies under the supervision of M. Gaug • further details on the methodology and calculation boundary conditions can be found in the paper McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

6. snout symmetry plane ingots steel sheet pot rolls baffle inductor sink roll inductor Numerical Model Geometry McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

7. Numerical Modelling Cases McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

8. Results - General Observations • Changing the strip width/speed • minor effect on the magnitude of the flow velocities, but not the overall fluid flow pattern • some effect on the temperature field due to varying heat input rates, but temperature was controlled to 460ºC and overall effect was minor • Overall circulation pattern consistent with that observed by previous authors • Presence or absence of the baffle determines the shape of the overall flow within the CGL McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

9. General Flow Pattern in CGL Bath McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

10. General Observations - cont’d • There were significant differences in the flow patterns between the centreline and offset ingot charging configurations • overall flow pattern a strong function of the baffle’s presence • For simplicity, all results presented further are for the 1.65 m (65 in.) strip at 99.1 m/min. (325 fpm) case • all velocity plots range of 0 - 0.150 m/s • all temperature plots range of 458 - 463ºC McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

11. Results - Detailed Observations • The model visualisations were performed via 2D cutting planes at various distances from reference planes • X-Y plane parallel to symmetry plane (reference plane) • X-Z plane parallel to top surface plane of the CGL bath (reference plane) McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

12. VC Ingot - X-Y (0.127m) w/o baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

13. VC Ingot - X-Y (0.127m) w/ baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

14. VC Ingot - X-Y (0.127m) w/o baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

15. VC Ingot - X-Y (0.127m) w/ baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

16. VC Ingot - X-Z (1.270m) w/o baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

17. VC Ingot - X-Z (1.270m) w/ baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

18. VC Ingot - X-Z (1.270m) w/o baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

19. VC Ingot - X-Z (1.270m) w/ baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

20. HC Ingot - X-Y (0.050m) w/o baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

21. HC Ingot - X-Y (0.050m) w/ baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

22. OV Ingot - X-Y (1.219m) w/o baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

23. OV Ingot - X-Y (1.219m) w/ baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

24. OV Ingot - X-Y (1.219m) w/o baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

25. OV Ingot - X-Y (1.219m) w/ baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

26. OV Ingot - X-Z (1.270m) w/o baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

27. OV Ingot - X-Z (1.270m) w/ baffle velocity McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

28. OV Ingot - X-Z (1.270m) w/o baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

29. OV Ingot - X-Z (1.270m) w/ baffle temp. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

30. Conclusions • The macroscopic/melting ingot flow calculated for the Pro-Tec CGL2 bath is in general agreement with those of previous authors. • The presence or absence of the deep baffle behind the snout has the largest effect on the bath flow - when present, it effectively isolates the charging area from the remainder of the bath with communication via flow under and around the edges of the baffle. • There are only slight difference between the VC and HC charging cases - orientation factors. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

31. Conclusions - cont’d • The OV charging case is significantly different from the VC and HC cases • interaction of the descending ingot flow with the return flow along the side walls and the rising inductor flow. • ingot material swept along the back wall of the pot before being drawn to the snout by the drag flow from the sheet. • overall pattern continues to be dominated by the baffle. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2

32. Acknowledgements The authors would like to thank Noranda Inc. and Pro-Tec Coating Co. for their permission to publish this paper. McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2