关键词: 错流移动床, 空腔, 压降

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