| 摘要 |
<p>PURPOSE:To perform classification of higher precision and to effectively and stably produce fine powder having the minute distribution of particle size by providing a raw material feeding pipe with an accelerating pipe part of a Laval pipe type and providing the accelerating pipe part with a raw material feeding port. CONSTITUTION:When a classifying region is evacuated through at least one of discharge ports 11, 12, 13, the flow of air is caused and turbulence is caused in a raw material feeding pipe 16 opening into the classifying region. Raw material powder fed from a raw material feeding port 8 is fed to the classifying region through the raw material feeding pipe 16, and flies about in a curved line 30 as shown by the broken arrow by the Coanda effect due to the action of a Coanda block 26 and the action of inflow gas, and is classified by the size of particle diameter. Large particles, medium particles and small particles are separately into a division outside a classifying edge 18, a division between the classifying edge 18 and a classifying edge 17 and a division inside the classifying edge 17 respectively. The large, medium and small particles are discharged from discharge ports 11, 12, 13 respectively.</p> |
