(316d) Computational Particle Fluid Dynamics Simulations and Validation for Cyclones: High and Low Loadings

Cyclones are ubiquitous devices
in unit operations across many chemical process industries (CPI).  They are deceptively simple devices
that are widely known to be problematic in actual practice.  Typical problems are appriori
prediction of the efficiency as a function of particle sizes, loading and
geometry variations and wall wear. The commercial Barracuda-CPFD^TM
software package was validated against a range of experimental data from PSRI
for high-loadings in a 50 cm diameter unit, and from Hoffman's data in a 20 cm
light-loading unit typical of tertiary cyclones. The new Barracuda commercial
software is an advanced math-based computational particle-fluid dynamics (CPFD^TM)
tool developed for fast and accurate simulation of dense-phase solids flows
within industry-scale CPI units. 
The software's numerical methodology uses a direct element method
wherein solids are modeled as discrete particles with proper size and density
distributions, and the fluid is modeled as a continuum.   This numerical technique, CPFD,
has enabled the accurate simulation of particle size effects and the near
closepacking at the walls in concert with the complex, three-dimensional gas
flow and vortex behavior. 
Comparisons are made to both high- and low-loading cyclone data sets for
the overall efficiency, the detailed grade efficiency, and the pressures drops.
Also given are the calculations of local wall wear and particle attrition due
to variations in loadings.  Finally,
detailed results are presented for a 1-meter diameter, primary commercial
cyclone with a fully submerged 10-meter dipleg.