入料颗粒在空气重介质流化床中所受合力是决定颗粒运动行为与分离特性的关键.在理论分析的基础上,建立了入料颗粒在流化床中运动时的受力平衡方程.采用自行研制的颗粒受力测量装置,对不同粒径示踪颗粒在流化床中的受力变化进行了准确测量,结果表明:对粒径为8～10mm、密度为7 850kg/m3的球形颗粒,在以0.3～0.1mm高密度磁铁矿粉作为加重质形成的稳定流化床中,其受力稳定,并与理论计算符合良好. The resultant force of the charged particles in the air-heavy medium fluidized bed is the key to determine the particle’s motion behavior and separation characteristics.Based on the theoretical analysis, the force balance equation of the charged particles in the fluidized bed is established. The self-developed particle force measurement device was used to accurately measure the force variation of tracer particles with different particle sizes in a fluidized bed. The results showed that the spherical particles with the diameter of 8 ~ 10mm and the density of 7 850kg / m3 Particles, in 0.3 ~ 0.1mm high-density magnetite powder formed as a heavier quality of the stable fluidized bed, the force was stable and in good agreement with the theoretical calculations.