Separation Characteristics of a Deflector Wheel Classifier in Stationary Conditions and at High Loadings: New Insights by Flow Visualization

Abstract

Although the deflector wheel classifier is the dominant separation device in the industrial separation of fine-grained particle fractions, the classifying mechanisms at high particle loadings are still not described and understood sufficiently. The existing models for the calculation of the separation efficiency, which are mostly based on a single particle’s fate, fail to capture the behavior at high particle loading where particle-particle and particle-wall collisions are encountered. To overcome this knowledge gap, a high-speed camera was used to analyze the particle movement in the separation process of a deflector wheel classifier representing real physical conditions. It is shown that particle-particle and particle-wall collisions must be included in a consistent theoretical model to represent the effective particle behavior in the separation process. In addition, the influence of process parameters such as revolution rate and mass loading on the separation efficiency of a deflector wheel classifier at high loadings is presented here.

Keywords

• particle size
• deflector wheel classifier
• cut point
• separation efficiency
• separation sharpness