D类粘性颗粒流化粘结规律

Fluidization and agglomeration laws for type D cohesive particles

为可视化研究流化床中的粘结行为,采用石蜡颗粒作为实验原料,动态模拟了D类粘性大颗粒的流化与粘结过程。实验结果表明:由正常流化到死床,可以分成2个阶段;第1个阶段是速度较慢的粘结核的形成及长大阶段,第2个阶段是速度很快地形成粘结块及死床阶段。然后,对压力信息进行了分析,发现采用平均压降来监测粘性大颗粒的早期结团在压力测点选择正确后具有适用性,但不能给出具体的数值变化量来界定粘结的开始及粘结程度。

Agglomeration in a fluidized bed was investigated using paraffin particles to simulate the fluidization and agglomeration of coarse type D cohesive particles. The processes from normal fluidization to shut-down can be divided into two stages. The first is a slower stage with the formation and growth of the bonded core followed by the formation of a large bonded block and shut-down. Analysis of the pressure signals shows that the average pressure at the right position shows a pattern of changes related to the degree of bonding, but does accurately identify the beginning of agglomeration nor can the pressure be correlated to specific numerical values of the bonding extent.