Modeling of Particle Separation in Bends of Rectangular Cross-section

A new theoretical model for predicting particle separation efficiency in bends is developed based on the investigation of flow pattern, the critical particle size separation theory and the boundary layer separation theory. The radial particle concentration gradient, instead of the usually assumed uniform radial particle concentration within the bends, is considered in this mathematical model. The local particle concentration and the separation efficiency can be calculated on the base of a time-of-flight model in terms of the particle size distribution of the feed. The effects of curvature ratio and bend angle on the separation efficiency in bends are also evaluated by the model.