中心气升式气固环流反应器中的颗粒速度分布

Particle Velocity Distribution in a Novel Draft Tube-Lifted Gas-Solid Air Loop Reactor

在一套连续进料的中心气升式气-固环流反应器装置上,考察了不同操作条件下各分区颗粒上行运动速度、下行运动速度及时均速度沿径向的分布规律,并与间歇操作时颗粒速度沿径向的分布规律进行了对比。研究发现,随着导流筒表观气速的增加,底部区域、导流筒中不同轴向截面处颗粒的上行运动速度和时均速度增加,下行运动速度减小,颗粒的环流速度增加。在相同的表观气速下,与间歇操作相比,连续操作时底部区域环隙下方颗粒的时均速度增加,主体向下流动;导流筒进料影响区颗粒的时均速度减小,返混增强;颗粒的环流速度增加。

Hydrodynamics in a novel gas-solid air-loop reactor was investigated experimentally. The upward and downward particle velocity and time-averaged particle velocity was measured by optical fiber probe under continuous and batching operating conditions. The experimental results show that with the increase of the superficial gas velocity of draft tube region the upward particle velocity and time-averaged particle velocity increase, while the downward particle velocity decrease. Significant differences of the distribution of particle velocity was found for continuous and batch operating conditions. The dominant movement direction of particles in the bottom region near the column wall is downward under continuous operating condition. And the time-averaged particle velocity is larger than that under batching operating condition. Also, the circulating velocity under continuous operating condition is larger.