下行气固两相流充分发展段的颗粒浓度

在较宽的操作条件范围内采用光纤颗粒浓度探头测定了下行管(φ100 mm×9.5 m)充分发展段内的真实颗粒浓度,并结合文献上的大量实验数据,系统研究了操作条件、颗粒直径和床层直径对下行气固两相流充分发展段内真实颗粒浓度的影响.结果表明,当操作气速一定时,充分发展段内的颗粒浓度随着颗粒循环速率的增大而线性增加.颗粒直径对下行床充分发展段内颗粒浓度的影响随操作气速的增加而逐渐减弱.床层直径对下行床充分发展段内的颗粒浓度基本上没有影响.所提出的预测关联式能很好地拟合本文及文献上的实验数据.

Solids Concentration in the Fully Developed Zone of CFB Downers

In order to investigate the solid concentrations in the fully developed region of the circulating fluidized bed(CFB)downers,the actual solid concentration was measured by an optical solid concentration probe in a 9.5 m high downer with fluid catalytic cracking(FCC)particles.Based on the experimental data from this work and in the literature,the influences of operating conditions,particle diameter and downer diameter on the solid concentration in the fully developed zone of CFB downers were studied.The results show that,for a given superficial gas velocity,the solid concentration linearly increases with the solid circulation rate,and the effect of particle diameter on the solid concentration in the fully developed zone of the CFB downers reduces with increasing superficial gas velocity.The results also show that the solid concentration in fully developed zone of CFB downers changes little with the downer diameter.Based on these facts,an empirical correlation used to predict the solid concentration in the fully developed zone of CFB downers was proposed.The comparison of the experimental data with the predicted values confirms the validity of the proposed correlation.