Abstract: To reduce the pressure drop of the parallel hydrocyclones, a new type of common liquid hopper for the circumferential type was designed. The pressure drop and separation efficiency of four conventional parallel hydrocyclones with and without the common liquid hopper were measured experimentally. The flow field inside the parallel hydrocyclones was numerically simulated using Fluent software, and the influence of common liquid hopper on the air core, tangential velocity, and swirl stability were analyzed. The results showed that the pressure drop of the parallel hydrocyclones group with common liquid hopper was lower than that of the conventional group, while the separation efficiency remained unchanged. The average pressure drop reduced by 1.9%, and the maximum pressure drop reduced by 3.36% when the inlet velocity reached 5.0 m/s. Compared with conventional parallel connection, a common liquid hopper could form a bottom flow liquid seal, causing the disappearance of air core in the parallel hydrocyclones group, resulting in a reduction in turbulent energy dissipation. And at high flow velocity, the area of quasi forced vortices expanded, making the gradient of tangential velocity change smoother and the maximum tangential velocity remained unchanged. So these phenomena helped to reduce energy consumption. A parallel vortex flow system could be formed inside a common liquid hopper. In this system, each flow vortex was constrained by other vortices. The oscillation amplitude of the vortex core in the system was smaller than that of a single vortex, so its stability was stronger. This self stability of the vortex flow system in the common liquid hopper also enhanced the stability of the swirling flow in each hydrocyclone, which helped to reduce pressure drop. Therefore, the common liquid hopper could reduce the pressure drop of parallel hydrocyclones while maintaining separation efficiency, providing guidance for the design and application of circumferential parallel hydrocyclones.

Key words: parallel hydrocyclones, common liquid hopper, pressure drop, air core, self-stability

摘要： 为降低并联水力旋流器组压降，设计了一种并联水力旋流器公共液斗。实验测量了常规并联旋流器组和带液斗的并联旋流器组的压降，并利用Fluent软件分析了并联分离器的流场。结果表明，带液斗的并联旋流器组的压降均低于常规组，平均减少了1.9%，当入口流速增大至5.0 m/s后，压降减小幅度最大达3.36%。带液斗的并联旋流器组的分离效率均高于常规组，平均增加了0.94个百分点，当入口流速增大至5.0 m/s后，分离效率增加幅度最大达1.34个百分点。与常规并联相比，带液斗的并联旋流器组内空气柱消失，导致湍动能耗散减小且切向速度变化更为平缓。液斗内并行涡流会受到其他旋涡约束，旋涡系中心比单个旋涡中心摆动幅度要小，稳定性更强。公共液斗能够有效降低并联旋流器分离压降，本工作可为并联水力旋流器的设计和应用提供指导。

关键词: 水力旋流器并联, 公共液斗, 压降, 空气柱, 自稳定性