Abstract: When a jet spouts vertically into a fluidized bed with a conical distributor, a jet zone is formed. In this jet zone, agglomerates will be disengaged downward from the fluidized bed consisting mainly of ash particles and then discharged from the jet nozzle. In general, this disengagement process for the agglomerates can be divided into three stages: 1 ) Initial disengagement. 2 ) Stable disengagement. 3 ) Critical disengagement.In this paper the equation obtained for the initial disengagement velocity UIJ is as follows: The difference between experimental and calculated values is less than ±5%. In practice, the flow characteristics and agglomerate disengagement process in the fluidized bed are affected by the geometric configuration of the jet zone. Based on experimental results, a configuration-flow parameter C, is proposed, which may be used as an important criterion for selecting the optimum geometric configuration of nozzle and distributor. Finally, the effect of fine powders on improving the agglomerate disengagement process is examined.

摘要： 本文研究了垂直射流喷入流化床时固体颗粒从喷口排出的稳定分离过程及初始分离速度U_(IJ)的确定;考察了射流区的几何结构对床层流动特性与分离过程的影响;提出用结构流动参数C_s来作为选取射流区合理几何结构的重要判据;指出了细粒组份对颗粒分离的改善作用.