Numerical study of the effect of cylinder–to–cone ratio on the classification performance in hydrocyclones

The separation space of hydrocyclone, including its cylindrical and conical sections, governs internal fluid dynamics and significantly affects classification performance. While the individual effects of these two sections are well–studied, the effects of cylinder–to–cone ratio (CCR) remain insufficiently explored. This study utilizes numerical simulations to assess the effects of different CCRs on hydrocyclone performance metrics, including classification performance, flow field characteristics, and volume fraction distributions across seven CCR configurations. The results show that as CCR increases from 1:9 to 9:1, the cut size increases from 16.4 μm to 30.4 μm, Ecart probable increases from 6.1 μm to 9.5 μm, the pressure drop decreases by 11 kPa, and the water split drops from 5.8% to 3.7%. Additionally, a smaller CCR enhances tangential velocity and pressure gradient, improves particle classification, stabilizes the air core, and reduces particle misplacement. These findings offer valuable insights into optimizing hydrocyclone design and classification performance to meet diverse application needs.