ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Experimental Assessment and CFD Simulations of Local Solid Concentration Profiles in a Pilot-Scale Stirred Tank

M. Špidla, M. Moštěk, V. Sinevič, M. Jahoda, and V. Machoň

Department of Chemical Engineering, Faculty of Chemical Engineering, Institute of Chemical Technology, CZ-166 28 Prague

E-mail: michal.spidla@vscht.cz

Abstract: An experimental assessment of solid particle distribution in a stirred vessel was performed by conductivity measurements, and for the same solid-liquid system, the capabilities of the Computational Fluid Dynamics (CFD) simulation were investigated.
A detailed particle distribution measurement of a solid-liquid suspension at the just-suspended state was carried out in a pilot-plant stirred vessel of one meter in diameter. This baffled stirred tank was agitated with a pitched blade turbine, which generates an axial-flow pattern in the tank. The water suspension of glass beads of diameter 0.35 mm was studied. Average particle concentration was 5 vol. %. In this mode of experimental arrangement, a particle-filled layer of suspension was observed. Axial and radial particle concentration gradients and their standard deviations were determined.
CFD simulations were performed using a two-phase model implemented in the commercial code Fluent 6.2. The Eulerian-Eulerian multiphase model was adopted in conjunction with the Multiple Reference Frames and the “mixture” k-ε turbulence model.
Computational results are compared with the experimental data and critically discussed. The simulation results are in agreement with experiment, but the drag coefficient for particles settling in a stagnant fluid needs to be corrected in order to obtain acceptable results for a turbulent flow regime.

Full paper in Portable Document Format: 596aa386.pdf

Chemical Papers 59 (6a) 386–393 (2005)