Accurate Wet-type Centrifugal Classification Using an Almost Rigidly Rotating Flow

Classification Principle and Performance of the Continuous-type Classification

Abstract

In this paper, we studied the performance of continuous wet-type centrifugal classification system which was developed based on the batch-type system with an almost rigidly rotating flow proposed in our previous paper. The continuous operation was achieved by extracting the coarse product from the equator of housing. We have experimentally investigated the influence of extraction on the classification performance and the critical extraction rate. We obtained the following conclusions; (1) extraction affects neither the stably-rotating flow nor the rotating stratified flow structure, although the rigid-rotation region of the batch-type shifted into an interior region and Ekman layers, (2) when the extraction rate is below the threshold value (critical extraction rate), the cut size and fine yield decrease with increasing extraction rate, but the sharpness index is almost as high as that for the batch-type, (3) the critical extraction rate is reduced with decreasing Ekman and Rossby numbers.