1. School of Chemical Engineering & Technology,China University of Mining and Technology (Beijing),Beijing　 100083,China; 2. China ENFI Engineer-ing Corporation,Beijing　 100038,China

试验研究了颗粒体积分数对液固流化床颗粒干扰沉降末速的影响,以准流体有效密度和表观黏度概念刻画床层内颗粒间相互作用,提出了新的干扰沉降末速模型,相对误差基本控制在10%以内,预测准确度比现有干扰沉降末速模型明显提高。利用提出的干扰沉降末速模型探究了等沉比随液固流化床层颗粒体积分数变化关系,发现等沉比随床层颗粒体积分数增大而增大,表明入料粒度范围变宽、粒度效应对重选的影响受到一定程度抑制。

A new hindered settling velocity model,based on Concha-Almendra free settling velocity model,was de- duced by using pseudo-fluid analogy and boundary layer theory,in which the effective density and apparent viscosity accounted for the interaction between particles in a solid-liquid two phase system. Sedimentation-Fluidization experi- mental system was set up and fluidization experiment was carried out. According to the experiment results,the hindered settling velocities of four kinds of particles under various particle volume fractions were obtained. Comparison between various hindered settling velocity models with the experimental values was performed,indicating the model deduced in the present study could give a more accurate prediction than others. Relative errors of the predicted hindered settling velocities of the four kind of particles by using the model in the present study were less than 10% . The influence of particles volume fraction of liquid-solid fluidized bed on equal settling ratio was analyzed. The results showed that e- qual settling ratio increased with particles volume fraction,indicating the impact of size effect on gravity separation was suppressed and feed size range could be allowed to be larger under a lower upward current velocity and larger particles volume fraction conditions.

SUN Mingyang,WEI Lubin. A hindered settling velocity model based on pseudo-fluid analogy[J]. Journal of China Coal Society,2018,43 (2):540-545.