Based on a cold-flow experimental setup, the transition between trickle flow and pulse flow in a 3D concurrent downflow three-phase moving bed is investigated by the standard deviation of pressure drop and visual observations. Results show that at a constant gas flow rate, the trickle-to-pulse transition shifts to a higher liquid flow rate with the increasing solid flow rate because the particle moving inhibits the formation of local liquid blockage. Furthermore, an empirical model is proposed to fit the trickle-to-pulse transition boundary by correlating the dynamic liquid holdup at the boundary with the gas Reynolds number, the particle velocity, and the relative viscosity. Finally, the effects of the particle moving on the liquid distribution are investigated, which shows that the particle moving makes the liquid distribution more uniform when the solid flow rate is smaller than a certain value. But further increasing the solid flow rate, the liquid distribution becomes uneven.

基于冷流实验装置，通过压降的标准偏差和视觉观察来研究3D并发下流三相移动床中的滴流和脉冲流之间的过渡。结果表明，在恒定的气体流速下，随着固体流速的增加，滴流到脉冲的过渡会转变为较高的液体流速，因为颗粒的移动会抑制局部液体堵塞的形成。此外，提出了一种通过将边界处的动态持液量与气体雷诺数，粒子速度和相对粘度相关联来拟合点滴至脉冲过渡边界的经验模型。最后，研究了粒子运动对液体分布的影响，这表明当固体流速小于一定值时，颗粒运动使液体分布更均匀。但是，进一步增加固体流速，液体分布变得不均匀。