Limiting efficiency for continuous drying of microparticle slurries in a powder-particle spouted bed

When a microparticle slurry is continuously dried in a powder-particle fluidized bed, agglomerates of microparticles and coarse particles are produced at high drying efficiency, and continuous operation is not achievable. To avoid agglomeration, it is very important to fluidize the coarse particles vigorously in the bed. For the same purpose, the continuous drying of microparticle slurry is investigated in a powder-particle spouted bed. In this dryer, the microparticle slurry can be continuously dried with higher drying efficiency comparing with an ordinary powder-particle fluidized bed. Limited drying efficiency is defined as the maximum drying efficiency for continuous operation at a certain gas velocity. An empirical equation for estimating the Limiting drying efficiency is obtained.