Classification

Particulate materials are produced intentionally or unintentionally inmany different processes. Classification is often required to produce a productthat has a given particle size range. In other cases particles have to be removed asfar as possible from a dispersion in a liquid or air/gas either to recover valuablematerials, or to eliminate health or explosion hazards, or to produce a clear fluid.This chapter gives an overview of the available techniques, especially the applica-tion and characteristics of (hydro)cyclones, since they are used in many applica-tions. The application of computational fluid dynamics in combination with (new)flow measurement techniques begins to provide new insight into the influence of thedetails of cyclone design on the flow patterns, the collection efficiency, the cut size,the pressure drop and potential erosion problems, and, thus, may relate to optimumdesigns in relation to required tasks