Abstract: The pressure drop of gas flowing through the cross-flow moving-bed was investigated in a two-dimension rectangular apparatus. The effects of particles flow rate, superficial gas velocity, formation and development of cavity/raceway and voidage of particles on the pressure drop were investigated experimentally with the operation conditions of 0~1.35 m/s of superficial gas velocity and 0.95~9.68 cm/min of particle velocity. The experimental results show that the particle velocity has little influence on the pressure drop; the phenomena of cavity and pinning occur when the cross-flow velocity is high enough. The development of a cavity or a raceway can cause three types of pressure drop with time, which are stabilization, slight fluctuation and severe fluctuation. The pressure drop of moving-bed can be calculated by Ergun's equation at low velocity of cross-flow gas. Cavity appears in a process cycle of "formation-growing up-collapsing-fluidization" at high gas velocity. On the basis of experimental results, a model for calculating the pressure drop when a cavity occurs and a dimensionless relationship of cavity size is conduced, which agree with the experimental data.

Key words: cross-flow moving bed, cavity, pressure drop

摘要： 在矩形移动床内考察了颗粒下移速度、颗粒堆积状态及空腔生成和长大发展过程等因素对压降的影响. 在错流气体速度为0.09~1.35 m/s、颗粒下移速度为0.95~9.68 cm/min的较大变化范围内进行了实验研究. 结果表明，颗粒下移速度对压降几乎没有影响；当错流气速足够大时移动床内将出现"空腔"和"贴壁"等现象，空腔的发展过程造成压降随时间出现稳定、微波脉动和大幅波动3种变化；欧根公式适用于低错流气速时的移动床压降；高错流气速下空腔出现了"生成-长大-塌落-流化"的循环变化过程. 在实验基础上建立了有空腔时的移动床压降模型，并对空腔尺寸进行了无因次关联，其床层压降的计算结果与实验值相符.

关键词: 错流移动床, 空腔, 压降