Analysis of Particle Cloud Height Dynamics in a Stirred Tank
Journal article, 2016

Local and temporal variations of the particle cloud formed in a cylindrical mixing vessel were investigated experimentally. Different particle sizes (0.5, 1, and 2 mm) and volumetric concentration up to 20 vol % were evaluated at different impeller speeds. The time-averaged cloud height was linear with impeller frequency and with volume concentration. Suspensions with larger particles had a lower average cloud height, while the standard deviation for the temporal cloud height variation was larger. Two strong periodic phenomena were identified to be dominating the particle cloud height variations. The frequencies were linear with impeller speed, resulting in dimensionless frequencies of S-1 = 0.02-0.03 and S-2 = 0.05-0.06. The frequencies were affected by neither the particle size nor the volumetric concentration. The amplitude showed no dependency on the particle size, but the S-2 amplitude significantly decreases and S-1 increases with increasing solid concentration. The results were compared to LES/discrete element method simulations and showed a fair agreement.

cloud height

Computational Fluid Dynamics

stirred tank

macroinstabilities

solid-liquid

Euler-Lagrange

Large Eddy Simulation

Author

Matthias Eng

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Environmental Science

Rasmus Jonsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Reaction Engineering

Anders Rasmuson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology, Chemical Environmental Science

AICHE Journal

0001-1541 (ISSN) 1547-5905 (eISSN)

Vol. 62 1 338-348

Subject Categories

Chemical Engineering

DOI

10.1002/aic.15051

More information

Created

10/8/2017