Metallurgical and Materials Transactions B

, Volume 47, Issue 5, pp 2732–2743 | Cite as

Microbubble Swarms in a Full-Scale Water Model Tundish

  • Sheng Chang
  • Xiangkun Cao
  • Zongshu Zou
  • Mihaiela Isac
  • Roderick I. L. GuthrieEmail author


Water modeling, using microbubble swarms, was performed in a full-scale, four-strand, delta-shaped tundish, located at the McGill Metals Processing Centre (MMPC). The objective of the study was to investigate the effectiveness of microbubbles in removing inclusions smaller than 50 μm, applying the principles and conditions previously researched using a smaller scale arrangement. Air was injected into a full-scale model of a ladle shroud (the connecting tube through which liquid steel flows into the tundish below). The model ladle shroud was fitted with twelve, laser-drilled orifices, so as to create microbubbles. The bubbles generated using different gas injection protocols were recorded using a high-speed camera, and the bubble images were postprocessed using the commercial software, ImageJ. With this newly designed ladle shroud, bubble sizes could be reduced dramatically, to as small as a 675 µm average diameter. A three-dimensional, CFD model simulation was developed, using parameters obtained from the corresponding water model experiments, in order to predict the behavior of these microbubbles within the tundish and their potential influence on flow patterns and inclusion float-out capability.


Bubble Size Liquid Steel Slide Gate Turbulent Dissipation Rate Inclusion Removal 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Drag coefficient (−)


Diameter of bubble (m)


Froude number (−)


Gravity acceleration (m2/s)


Generation rate of turbulence kinetic energy (−)


Height of liquid bath


Turbulence intensity (−)


Turbulent kinetic energy (m2/s2)


Turbulence length scale (m)


Characteristic length (m)


Eddy length scale (m)


Length scale associated with small vortices (m)

\( \dot{m}_{\text{b}} \)

Mass flow rate of bubbles (kg/s)


Number density of inclusions (number/m3)


Number of inclusions removed per unit time (number/s)


Number of bubbles (−)


Pressure (Pa)


Attachment, collision, and adhesion probability between inclusion and bubbles (−)


Gas flow rate (m3/s)


The radius of the gas injection port (m)


Reynolds number (−)


Stokes number (−)


Eddy crossing time (s)


Bubble residence time (s)


Time step (s)

u, ub

Velocity of fluid flow and bubbles (m/s)

uav, u

Average fluid velocity and the fluctuation of the velocity (m/s)


Velocity of the gas crossing the orifice (m/s)


Swept volume (m3)


Critical Weber number (−)

ρ, ρg

Densities of liquid and gas (kg/m3)


Turbulent dissipation rate (m2/s3)


Normally distributed random number (−)

μeff,μ, μt

Effective viscosity, laminar viscosity, and turbulent viscosity (kg/(m s))


Surface tension (N/m)

τe, τp

Eddy life time and relaxation time (s)


Dissipative ladle shroud


Discrete phase model


Residence time distribution


Submerged entry nozzle



The authors are indebted to NSERC, and to RTIT for research funding, to the MMPC for giving access to all its research facilities, and to ANSYS Inc. for providing the license of Fluent. The first author is also grateful to the China Scholarship Council for the financial support during his Ph. D studies at McGill.


  1. 1.
    Y. Miki, B. G. Thomas Metall. Mater. Trans. B, 1999, vol. 30B, pp. 639-654.CrossRefGoogle Scholar
  2. 2.
    Y. Sahai and T. Emi: ISIJ Int., 1996, vol. 36, pp. 667-672.CrossRefGoogle Scholar
  3. 3.
    C. Chen, L. T. I. Jonsson, A. Tilliander, G. G. Cheng, P. G. Jonsson: Metall. Mater. Trans. B, 2015, vol. 46B, pp. 169-190.CrossRefGoogle Scholar
  4. 4.
    D. Mazumdar and R. I. L. Guthrie: ISIJ Int., 1999, vol. 39, pp. 524-547.CrossRefGoogle Scholar
  5. 5.
    P. K. Jha, P. S. Rao and A. Dewan: ISIJ Int., 2008, vol. 48, pp. 154-160.CrossRefGoogle Scholar
  6. 6.
    R. D. Morales, J. D. J. Barreto, S. Lopez-Ramirez, J. Palafox-Ramos and D. Zacharias: Metall. Mater. Trans. B, 2000, vol. 31B, pp. 1505-1515.CrossRefGoogle Scholar
  7. 7.
    A. Cwudzinski: Steel Res. Int., 2014, vol. 85, pp. 902-917.CrossRefGoogle Scholar
  8. 8.
    K. Morales-Higa, R. I. L. Guthrie and M. Isac: Metall. Mater. Trans. B, 2013, vol. 44B, pp. 63-79.CrossRefGoogle Scholar
  9. 9.
    S. Lopez-Ramirez, J. D. J. Barreto, Palafox-Ramos, R. D. Morales and D. Zacharias: Metall. Mater. Trans. B, 2001, vol. 32B, pp. 615-627.CrossRefGoogle Scholar
  10. 10.
    L. F. Zhang, J. Aoki and B. G. Thomas: Metall. Mater. Trans. B, 2006, vol. 37B, pp. 361-379.CrossRefGoogle Scholar
  11. 11.
    H. L. Yang, P. He and Y. C. Zhai: ISIJ Int., 2014, vol. 54, pp. 578-581.CrossRefGoogle Scholar
  12. 12.
    A. Vargas-Zamora, R. D. Morales, M. Diaz-Cruz, J. Palafox-Ramos, J. D. J. Barreto-Sandoval: Metall. Mater. Trans. B, 2004, vol. 35B, pp. 247-257.CrossRefGoogle Scholar
  13. 13.
    J. Wang, M. Y. Zhu, H. B. Zhou, Y. Wang: J. Iron Steel Res. Int., 2008, vol. 15(4), pp. 26-31.CrossRefGoogle Scholar
  14. 14.
    A. Cwudzinski: Steel Res. Int., 2010, vol. 81, pp. 123-131.CrossRefGoogle Scholar
  15. 15.
    J. P. Rogler, L. J. Heaslip and M. Mehrvar: Can. Metall. Q., 2003, vol. 43, pp. 407-415.CrossRefGoogle Scholar
  16. 16.
    A. Ramos-Banderas, R. D. Morales, L. Garcia-Demedices and M. Diaz-cruz: ISIJ Int., 2003, vol. 43, pp. 653-662.CrossRefGoogle Scholar
  17. 17.
    S. Chang, L. C. Zhong and Z. S. Zou: ISIJ Int., 2015, vol. 55, pp. 837-844.CrossRefGoogle Scholar
  18. 18.
    L. F. Zhang and S. Taniguchi: Int. Mater. Rev., 2000, vol. 45, pp. 59-82.CrossRefGoogle Scholar
  19. 19.
    K. Chattopadhyay, M. Isac and R. I. L. Guthrie: ISIJ Int., 2011, vol. 51, pp. 573-580.CrossRefGoogle Scholar
  20. 20.
    X.Y. Ren, Master Thesis, McGill University, Montreal, QC, Canada, 2014.Google Scholar
  21. 21.
    R.I.L. Guthrie and M. Isac: ISSTech Conf. 2003, AIST, Indianapolis, IN, 2003, pp. 1201–11Google Scholar
  22. 22.
    W. P. Jones and B. E. Launder: Int. J. Heat Mass Transfer, 1972, vol. 15, pp. 301-314.CrossRefGoogle Scholar
  23. 23.
    B. E. Launder and D. B. Spalding: Comput. Methods Appl. Mech. Eng., 1974, vol. 3, pp. 269-289.CrossRefGoogle Scholar
  24. 24.
    S. A. Morsi and A. J. Alexander: J. Fluid. Mech., 1972, vol. 55, pp. 193-208.CrossRefGoogle Scholar
  25. 25.
    FLUENT 14.5 Theory Guide, Section 16.2.2.Google Scholar
  26. 26.
    G. S. Dobby and J. A. Finch: Int. J. Miner. Process., 1987, vol. 21, pp. 241-260.CrossRefGoogle Scholar
  27. 27.
    A. V. Nguyen, H. J. Schulze, and J. Ralston: Int. J. Miner. Process., 1997, vol. 51, pp. 183-195.CrossRefGoogle Scholar
  28. 28.
    A. V. Nguyen: J. Colloid Interface Sci., 1994, vol. 162, pp. 123-138.CrossRefGoogle Scholar
  29. 29.
    M. E. Weber and D. Paddock: J. Colloid Interface Sci., 1983, vol. 94, pp. 328-335.CrossRefGoogle Scholar
  30. 30.
    S.H. Marshall, M.W. Chudacek, and D.F. Bagster: Chem. Eng. Sci., 1993, vol. 48, pp. 2049-2059.CrossRefGoogle Scholar
  31. 31.
    J. O. Hinze: AIChE J., 1955, vol. 1, pp. 289-295CrossRefGoogle Scholar
  32. 32.
    G. M. Evans, G. J. Jameson and B. W. Atkinson: Chem. Eng. Sci., 1992, vol. 47, pp. 3265-3272.CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2016

Authors and Affiliations

  • Sheng Chang
    • 1
    • 2
  • Xiangkun Cao
    • 2
  • Zongshu Zou
    • 1
  • Mihaiela Isac
    • 2
  • Roderick I. L. Guthrie
    • 2
    Email author
  1. 1.School of Materials and MetallurgyNortheastern UniversityShenyangP.R. China
  2. 2.McGill Metals Processing CentreMcGill UniversityMontrealCanada

Personalised recommendations