利用离心喷雾干燥制备球形粉体的工艺因素研究

研究了铝矾土料浆的离心喷雾造粒过程,考察了料浆固含量、粘度、喷雾头的旋转速度对粉体干燥的影响.从颗粒内部水分迁移的距离、空气进出口温度两方面,分析了蘑菇头颗粒、变形颗粒、球形颗粒和破裂颗粒等颗粒形貌的形成原因,并优化了一组工艺参数:喷雾头转速为12000r/min,料浆固含量为50%,热风入口温度为300℃,废气出口温度为115℃,塔内负压为-350Pa,料浆流速为4L/h,料浆的粘度为14s,在此条件下能制备出球形度高、颗粒粒径集中分布在55μm左右的粉体.

Study on Process Factors Using Centrifugal Spray Drying to Prepare Spheric Powders

The centrifugal spray drying process of bauxite slurry is studied,the influence of slurry solids content,viscosity and rotation rate is investigetaed. The formation causes about the mushroom head-liked particles,anamorphic particles,spheric particles, cracked particles etc. are analyzed from two sides, which are the transfer distance of moisture in the particles and in/out air temperature. The optimal operation parameters are obtained to prepare high spheric particles with the diameter distribution of 55μm: rotation frequency of spray head is 12000r/min,solids content of slurry is 50%,inlet temperature of hot air is 300℃ ,outlet temperature of exhaust gas is 115℃, press of tower is -350Pa, flow speed of slurry is 4L/h and viscosity is 14s.