Abstract
Trajectories of particles thrown into a forced vortex type centrifugal air classifier are presented to clarify the causes of classification error. The cascade flow is calculated with a finite element method applied to the potential equation. The analysis of particle trajectories rests on the assumption of low volumetric solid/gas ratios so that the flow field is not appreciably disturbed. The obtained results show that a trajectory is affected significantly by the position of the collisions with the blade-walls. A particle thrown in a classifier with a narrow blade interval generally moves outside of a cascade and travels a very long distance before it is classified.
