Abstract: Axial mixing and segregation were investigated by use of a "rapid section-cutting" fluidized bed. The axial variation oi particle size distribution, mean size and local voidage was measured. The particle motion was found to have random behavior. A random walk mode] was developed by using the Markov Process to characterize mixing and segregation of fluidized wide sizedparticles. Two systems, ilmenite and quartz, were tested with particle size between 0.04 and 0.40mm. The results showed that the minimum fluidization velocity, expansion behavior ot particles, the axial variation of particle size distribution, mean size and local voidagc could be predicted by the model accurately and convienently.

摘要： 用快速切割流化床研究了宽粒级液固流态化的轴向混合和分离,测定了粒度分布、平均粒径和空隙度沿床高的变化.证实了颗粒的运动有随机性.用马尔柯夫过程建立了一个随机游走模型,描述了流化床中宽粒体系的混合和分级特性.对钛铁矿和石英砂(粒径0.04～0.40mm)进行了检验.结果表明,体系的初始流态化速度、膨胀性质、粒度分布以及平均粒径和空隙度沿床高的变化的测定结果,同模型的预测值很好符合.