Abstract: The development of efficient catalyst classification technologies is crucial for optimizing fluid catalytic cracking (FCC) and catalytic pyrolysis coupling processes, where distinct particle size distributions are required for different reaction pathways. In this study, a large-scale cold-model experimental platform of a multi-arm vortex separator is established to explore the influence of operating conditions on classification behavior. Systematic experiments are conducted by changing ejection gas velocity (8~20 m/s), inlet particle concentration (30~70 g/m3), and bed linear velocity (0.15~0.25 m/s). The results demonstrate that ejection gas velocity governs classification sharpness by controlling the entrainment of fines within the coarse fraction. The increase in ejection gas velocity enlarges the upward axial gas velocity inside the device, thereby enhancing the entrainment effect on particles near the vortex arm outlets. Increasing the ejection gas velocity from 12 to 16 m/s reduces proportion of fine particles in coarse components from 14% to 12%. The inlet particle concentration imposes competing effects on classification performance: while higher concentrations promote agglomeration and modify turbulence distribution, and excessive loading intensifies fine-particle entrainment, thereby diminishing classification selectivity. The system maintains stable pressure drop characteristics under different bed linear velocities, with the pressure drop increasing by maximum of about 15% when the bed linear velocity is raised from 0.15 m/s to 0.25 m/s. Analysis of grade efficiency curves reveals classical S-shaped profiles with cut sizes (dc50) shifting under different operating regimes. Higher particle concentrations reduces dc50, favoring fine-particle removal, while higher ejection gas velocities enlarge dc50, moving the classification boundary toward larger sizes. These findings confirm the synergistic effect of ejection gas velocity and inlet concentration, highlighting that rational parameter matching can simultaneously improve efficiency and selectivity. Beyond the experimental findings, this work emphasizes the broader applicability of multi-arm vortex separators in refining and petrochemical processes. By enabling precise adjustment of particle size distribution, the system offers a promising pathway for enhancing catalyst utilization, extending catalyst lifetime, and facilitating process intensification in coupled FCC-pyrolysis units.

Key words: vortex separation, classification performance, grade efficiency, pressure drop

摘要： 针对催化裂化与催化裂解耦合工艺对不同粒度分布催化剂的分级需求，设计并搭建了多旋臂旋流分级大型冷模实验平台，系统考察了喷出气速与入口颗粒浓度对分级性能的影响。结果表明，喷出气速是影响分级锐度的关键因素，适度提高喷出气速可减少中细组分(≤40 μm)颗粒的夹带并改善分级清晰度；入口颗粒浓度为20 g/m3时，喷出气速由12 m/s增至16 m/s时，粗组分中细颗粒占比由14%降低至12%。入口颗粒浓度在较大范围内对分级性能表现出显著的调控效应。随着入口颗粒浓度升高，颗粒间更易发生团聚，同时湍流强度有所减弱，有助于增强细颗粒的捕集能力。然而，过高的入口颗粒浓度也会导致粗组分中细颗粒夹带比例增加，从而削弱分级选择性。多旋臂旋流器在不同床层线速度下均表现出压降波动小、运行稳定的特征，其中床层线速度为0.25 m/s时的压降较0.15 m/s时最大增加约15%。综合分析表明，喷出气速与入口颗粒浓度对分级性能具有协同作用，合理匹配操作参数可实现分级效率与分级选择性的优化。

关键词: 旋流分离, 分级性能, 粒级效率, 压降