The commercial utilization of fluidized beds is usually limited by particle agglomeration and subsequent defluidization. In this paper, a new mathematical model based on force balance is proposed to predict the defluidization behavior of particles in fluidized beds. In this model, the cohesive forces between particles are characterized using particle apparent viscosity and the separating force is mainly determined by the drag force. When the cohesion force was equal to the separating force at different fluidization condition, the minimum fluidization velocity and defluidization temperature were obtained by the model. Further, the fluidization behavior of copper particles including the minimum fluidization velocity and the temperature under which defluidization occurred was examined in a laboratory’s fluidized bed reactor. Compared with the experimental data, the results predicted by the model represent good agreement.

流化床的商业利用通常受到颗粒团聚和随后的脱流作用的限制。本文提出了一种基于力平衡的新数学模型来预测流化床中颗粒的脱流行为。在该模型中，颗粒之间的内聚力用颗粒表观粘度来表征，分离力主要由阻力决定。在不同流化条件下，当内聚力等于分离力时，模型得到了最小流化速度和脱流温度。此外，在实验室的流化床反应器中检查了铜颗粒的流化行为，包括最小流化速度和发生脱流的温度。