Effect of impeller type on mixing of highly concentrated slurries of large particles--颗粒学报PARTICUOLOGY

Kazemzadeh, A., Ein-Mozaffari, F., & Lohi, A. (2020). Effect of impeller type on mixing of highly concentrated slurries of large particles. Particuology, 50, 88-99. https://doi.org/10.1016/j.partic.2019.07.004

Effect of impeller type on mixing of highly concentrated slurries of large particles

Argang Kazemzadeh, Farhad Ein-Mozaffari ^*, Ali Lohi

Department of Chemical Engineering, Ryerson University, 350 Victoria Street, Toronto, M5B 2K3, Canada

10.1016/j.partic.2019.07.004

Volume 50, June 2020, Pages 88-99

Received 6 February 2019, Revised 12 May 2019, Accepted 8 July 2019, Available online 6 September 2019, Version of Record 7 April 2020.

E-mail: fmozaffa@ryerson.ca

Highlights

• Mixing of highly concentrated slurries was assessed for different impeller types.

• Performances of PBT, A310, and PF3 were analyzed using tomography.

• Solid particle distribution in the slurry tank was quantified using tomography.

• Velocity and turbulent kinetic energy profiles were found for all impellers.

• PBT was the most efficient impeller for mixing highly concentrated slurries.

Abstract

Many chemical engineering processes deal with dense suspensions of large solid particles in liquid. Behaviors of such systems are difficult to predict because the many solid particles strongly affect the hydrodynamics produced by the impeller. The main objective was to assess the performances of the PBT, A310, and PF3 impellers in agitating highly concentrated slurries of large particles. Electrical resistance tomography was used to determine the degree of homogeneity and solid particle distribution within the slurry reactor. To gain more insight into the complex behavior of the flow inside the dense suspensions, computational fluid dynamics simulations were conducted using a Eulerian‒Eulerian multiphase model. Both qualitative and quantitative analyses were performed to obtain details on the dispersed solid phase distribution and its effect on the mixing quality. We found that the PBT impeller was the most efficient in terms of consuming power and generating velocity and turbulent kinetic energy within the mixing tank.

Graphical abstract

Keywords

Suspension; Highly concentrated slurry; Electrical resistance tomography; Computational fluid dynamics; Homogeneity

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