粗大粒子分級型サイクロンにおいて粒子濃度が分級性能へ及ぼす影響

We have developed and evaluated a cyclone type classifier with improved collection boxes for classifying particles swilling down near the wall surface in order to separate coarse particles. These studies were performed under low solids loading condition to clarify the classification mechanism. However, the further examination under high solids loading condition is indispensable to the practical application. In this study, the particles feed rate was increased from 2 g/min up to 100 g/min. The remarkably high concentration of particle provably aggregates particles near the wall at the inlet, causing the saltation flow, targeted for the classification in our study, to transfer into sliding bed flow where the classification is impossible. Therefore, we introduced the secondary flow injected in the upper section of the cyclone. The secondary flow could disperse the particles and minimize the decrease in the classification performance. This result showed that the device is sufficient for practical use.