摘要
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。
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.
关键词
离心喷雾干燥
工艺因素
粒度分布
球形度
centrifugal spray drying, process factors, granularity distribution, sphericity
