Slide1 l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 19

CFD-Based Multiscale Modelling of Bubble-Particle Collision Rates and Efficiencies in a Flotation Cell PowerPoint PPT Presentation


  • 123 Views
  • Uploaded on
  • Presentation posted in: General

CFD-Based Multiscale Modelling of Bubble-Particle Collision Rates and Efficiencies in a Flotation Cell. Tom Liu, Peter Koh and Phil Schwarz CSIRO Minerals. Multiscale Modelling in Industrial Systems . Team Members: Phil Schwarz, CM (Project leader) Nick Stokes, CMIS Murray Rudman, CMIT

Download Presentation

CFD-Based Multiscale Modelling of Bubble-Particle Collision Rates and Efficiencies in a Flotation Cell

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Slide1 l.jpg

CFD-Based Multiscale Modelling of Bubble-Particle Collision Rates and Efficiencies in a Flotation Cell

Tom Liu, Peter Koh and Phil Schwarz

CSIRO Minerals


Multiscale modelling in industrial systems l.jpg

Multiscale Modelling in Industrial Systems

Team Members:

Phil Schwarz, CM (Project leader)

Nick Stokes, CMIS

Murray Rudman, CMIT

Alf Uhlherr, CMS

Peter Witt, CM

Paul Cleary, CMIS

Tom Liu, CM


Outline l.jpg

Outline

  • Background information

  • Brief introduction to multiscale modelling

  • Brief introduction to the modelling of flotation processes

  • CFD-based multiscale modelling strategy for a flotation cell

  • Some simulation results and future works

  • Conclusions


Background information l.jpg

Background Information

Froth flotation is a complex three phase physico-chemical processes

Prediction of flotation kinetics has not been possible


Life is not simple l.jpg

Life Is Not Simple

The extension of direct free-surface modelling techniques to resolve every bubble and particle in a industrial-scale vessel would require far more computational power than will be available


Multiscale modelling l.jpg

Jenkins et al.ICCS 2005, Atlanta

Multiscale Modelling


Multiscale modelling methods l.jpg

Jenkins et al., ICCS 2005, Atlanta

Continuum model

Molecular model

Multiscale Modelling Methods

  • Domain decomposition method

  • Process decomposition method

Jenkins et al.ICCS 2005, Atlanta


Current modelling methods for flotation processes l.jpg

Koh et al.(2003)

Current Modelling Methods For Flotation Processes

  • Correlation methods

  • First-principles methods

  • CFD methods


Examples of problems l.jpg

Examples of Problems

?

Nguyen & Kmet (1992)


Examples of problems10 l.jpg

Examples of Problems

Koh & Schwarz (2003)


Examples of problems11 l.jpg

Prediction formula:

Quiescent condition

Bubble size

Bubble rising velocity

Bubble Re

Collision efficiency

Flotation cell:

Turbulent condition

Stirring speed, cell structure, gas flow rate, … Bubble size, bubble velocity, bubble Re

Collision efficiency

Examples of Problems


Structure of cfd based multiscale flotation modelling l.jpg

Five different types of computational experiments are defined to calculate:

(1)Bubble-particle collision frequencies

(2)Bubble-particle collision efficiencies

(3)Bubble-particle attachment and detachment rates

(4)Drag coefficients for bubbles

(5)Bubble coalescence and break-up rates

CFD Model with time averaged RANS and multifluid techniques through suitable microscale closure relations

Structure Of CFD-based Multiscale Flotation Modelling


Some results l.jpg

Some Results

  • A wavelet-based adaptive mesh scheme to track moving free surfaces

  • 2D CFD turbulent collision model

  • 3D CFD model for Non-Newtonian drag coefficients


Bubble rising simulation l.jpg

Bubble Rising Simulation

A wavelet-based adaptive mesh scheme was embedded into CFX to track moving free surfaces


Bubble particle collisions l.jpg

Bubble-Particle Collisions


Slide16 l.jpg

Comparisons Between CFD Predicted Turbulent Collision Efficiencies and Laminar Collision Efficiencies


Comparisons between drag coefficients for newtonian and non newtonian fluids l.jpg

Comparisons Between Drag Coefficients for Newtonian and Non-Newtonian Fluids


Further works l.jpg

Further works

  • 3D CFD turbulent collision model

  • LES of bubble-particle collision

  • 2D CFD turbulent collision frequency model

  • CFD bubble coalescence/breakup model

  • Coupling macroscale model to microscale models


Conclusions l.jpg

Conclusions

  • Multiscale modelling strategy for a flotation cell

  • Wavelet-based adaptive moving mesh scheme

  • CFD-based numerical experiments for turbulent bubble-particle collisions and Non-Newtonian drag coefficients

  • Further works


  • Login