1 / 24

By: Mohsen Karimi Co-authors : Guven Akdogan Kiran Dellimore Steven Bradshaw

Comparison of different drag coefficient correlations in the CFD modelling of a laboratory-scale Rushton-turbine flotation tank. By: Mohsen Karimi Co-authors : Guven Akdogan Kiran Dellimore Steven Bradshaw. Outline. Single-phase modelling Gas-liquid modelling Sparger designs

anakin
Download Presentation

By: Mohsen Karimi Co-authors : Guven Akdogan Kiran Dellimore Steven Bradshaw

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Comparison of different drag coefficient correlations in the CFD modelling of a laboratory-scale Rushton-turbine flotation tank By: Mohsen Karimi Co-authors: GuvenAkdogan KiranDellimore Steven Bradshaw

  2. Outline • Single-phase modelling • Gas-liquid modelling • Sparger designs • Gas holdup prediction • Different drag coefficients • Bubbles size predictions • Flotation modelling • Flotation kinetics • Sub-processes

  3. Single-phase • Impeller modelling • Comparing Multiple Reference Frame (MRF) & Sliding Mesh (SM) • Turbulence models • Computational Domain Representation • Two types of stirred tanks • Grid resolution • Periodicity

  4. Single Phase Modelling • Unbaffled six-bladed tank & Rushton-turbine flotation tank

  5. Single Phase Modelling • Rushton-turbine flotation tank

  6. Single-Phase Modelling • Flow Pattern

  7. Gas-Liquid Modelling • Motivation Is there a need to compare different drag coefficient correlations? • Available solver’s options • Slip velocity between air bubbles and the surrounding liquid

  8. Motivation • Where does it affect? Interfacial force

  9. Gas-Liquid Modelling • Interfacial force • Different equations for CD have been implemented into the CFD solverfor different flow regimes.

  10. Gas-Liquid Modelling • Simulation Matrix

  11. Numerical Approach

  12. Numerical Approach • Mesh

  13. Gas-Liquid Modelling: Numerical Approach • Different sparger configurations • Disk and Ring in different locations with respect to the impeller

  14. Results

  15. Results

  16. Results • Gas distribution around the impeller

  17. Results Lane Bakker Schiller-Naumann

  18. Gas-Liquid Modelling • Air bubbles streamlines

  19. Gas-Liquid Modelling • Bubble size predictions • Additional PDE in order to account for the coalescence and breakup

  20. Flotation Modelling • Two types of PDE to include all sub-processes

  21. Flotation modelling • Parametric study of bubble particle collision rate • Angular velocity (350 – 800rpm) • Solid % (5 -25) • Particle diameter (8 - 90mm) • Bubble diameter (0.8 – 1.9mm) • Gas velocity (0.1 - 0.55 cm/s) 350rpm 800rpm Contour plot of collision rate

  22. Conclusion

  23. Acknowledgements • Prof. G. Akdogan • Prof. S.M. Bradshaw • OUTOTEC (Western Cape Branch)

More Related