Terminal Settling Velocity of a Sphere in a non-Newtonian fluid

  • Author / Creator
    Shokrollahzadeh, Ameneh
  • The production and disposal of thickened tailings continue to grow in importance in the mining industry around the world. Prediction of particle settling during transportation and handling processes is a critical element in system design and operation. Wilson et al. (2003) presented a direct method that was able to provide reasonably accurate predictions for the terminal settling velocity of a sphere in a fluid with a yield stress. The application of this method is limited; if the fluid yield stress is larger than the reference shear stress proposed by this method (0.3τ ̅≤τ_(y )), the correlation cannot be used. The current study presents measurements of fall velocities of precision spheres in concentrated Kaolinite-water suspensions (10.6% to 21.7% by volume). Both Casson and Bingham models have been used to model the fluid rheology which provided yield stress values in the range of 1.3 Pa to 30 Pa, depending primarily on the clay concentration. An analogy of the Wilson-Thomas analysis for pipe flow of non-Newtonian fluids (Wilson and Thomas, 1985) has been used to develop a new method for predicting the terminal settling velocity of a sphere in a viscoplastic fluid. There are no limits for applicability of the new method and its performance on the experimental results from this study, along with data taken from the literature, shows higher accuracy in its predictions than the direct method of Wilson et al. (2003).

  • Subjects / Keywords
  • Graduation date
    Fall 2015
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.