循环流化床中C类颗粒的干燥

摘要

为将循环流化床(CFB)技术应用于C类颗粒(＜30μm)的干燥,在自建的循环流化床(内径0.104 m×高2.35 m)内,以玉米淀粉(dp=8 μm,ρp=800 kg/m3)为研究对象,考察了不同操作参数对其干燥特性及干湿分离情况的影响.结果表明:循环流化床适用于C类颗粒的干燥;干燥速率随气速及进风温度的增大而增大,实验操作范围内初始含水质量分数对干燥速率的影响不大,较高的提升管具有更广的气速操作范围,系统物料循环更为稳定;分离速率随气速及进风温度的增加而增加,分离含水质量分数随气速及进风温度的增加而降低,但气速的影响更为显著.%In order to apply the circulating fiuidized bed (CFB) to the drying of group C particles ( ＜ 30μm) , with corn starches( dp = 8 μm,ρp = 800 kg/m3) as group C particles, the effect of different operation parameters on drying characteristics and separation efficiency were determined in a self-built CFB (0. 104 m ID ×2.35 m high) dryer. The results indicate that the CFB dryer is available for drying group C particles; the drying rate increases with the increasing of inlet air temperature and gas velocity, and the effect of initial moisture mass fraction on the drying rate is negligible compared with the other variables; the higher riser has a wider operating range of gas velocity and a more stable materials circulating system; the separation rate increases with the increasing of inlet air temperature and gas velocity, and the separation moisture mass fraction decreases with the increasing of inlet air temperature and gas velocity, but the effect of gas velocity is more pronounced.