Numerical scale-up study for orthokinetic agglomeration in stirred vessels

ED Hollander, JJ Derksen*, LM Portela, HEA Van den Akker

*Corresponding author for this work

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Scale-up of orthokinetic agglomeration in stirred-tank reactors was studied numerically. A computer code based on the lattice-Boltzmann method was used to perform large eddy simulations. To account for the dependence of agglomeration on hydrodynamics, the kinetic relation proposed by Mumtaz et al. was applied locally. The convection-reaction equation governing the evolution of the particle-number concentration was solved at the same resolution as the flow field. Three scale-up rules were studied: scale-up at constant Re-number, constant specific power input, and constant impeller tip speed. Vessel sizes varying from 1 to 10,000 L were simulated. The use of two types of impellers (Rushton turbine and Pitched Blade turbine) allowed for investigating the dependence of agglomeration on the macroscopic flow pattern in a reactor. Inhomogeneities in stirred-tank flow caused unpredictable scale-tip behavior. Scale-up at constant power input yielded the most constant reactor performance. Impeller geometry had a drastic impact on the observed agglomeration rate, even if the difference in Po number was taken into account.

Original languageEnglish
Pages (from-to)2425-2440
Number of pages16
JournalAIChE Journal
Volume47
Issue number11
Publication statusPublished - Nov 2001

Keywords

  • CALCIUM-OXALATE MONOHYDRATE
  • LARGE-EDDY SIMULATIONS
  • PRECIPITATION
  • AGGREGATION
  • FLOW
  • COLLISION

Cite this

Hollander, ED., Derksen, JJ., Portela, LM., & Van den Akker, HEA. (2001). Numerical scale-up study for orthokinetic agglomeration in stirred vessels. AIChE Journal, 47(11), 2425-2440.