文档介绍：Design and Optimization of a Vortex Particle Separator
for a Hot Mix Asphalt Plant
Andrew Hobbs
Astec Industries, Chattanooga, TN 37407

Abstract
Particle/gas separation is a necessary step in the production of Hot Mix Asphalt (HMA). Process
requirements demand a very specific separation criteria. In addition, the pressure drop associated with the
separation stage must be minimized to reduce the static pressure required from the fan. The intent of this
study was to design and optimize an inline cyclonic particle separator as the primary collector for a HMA
plant. Computation Fluid Dynamics (CFD) methods were used to investigate the effects of the device
geometry on particle collection. Parametric studies of the geometry were plished using ICEMCFD’s
direct CAD interface in SolidWorks. The Reynolds Renormalization Group (RNG) k −ε turbulence model
was used to model the swirling flow. Particle tracking was performed to predict collection efficiency using
a Discrete Phase Model (DPM). The Haider and Levenspeil modification was made to the DPM to better
model non-spherical particles trajectories. Particle-wall interaction was investigated by varying the
Coefficient of Restitution. The predicted collection efficiency pared to a similar CFD analysis of
the existing HMA cyclone design and to empirical data. The optimized inline cyclonic separator was
shown to plish qualitatively better collection efficiency at a fraction of the pressure drop of the
existing design.
Introduction
Hot mix asphalt (HMA) is the mon road surfacing material used in the United States. Between
450,000,000 and 500,000,000 tons of hot mix asphalt are produced annually in the . alone. HMA is
comprised of sand and various sizes of crushed rock, called aggregate, which is mixed together with liquid
asphalt cement. The liquid asphalt cement acts as a binder. The mixture is thermoformable and begins to
set at temperatures below 300o F.
The modern ho