Experimental Study of Mini-hydrocyclones with Different Top-plate Angles and Application in Quench Water Treatment System

Mini-hydrocyclones achieve separation through their internal, complex, and intense vortex flow fields. A comprehensive investigation into the stability of this flow field is crucial. While our prior work explored separation performance under various inlet angles, this study introduces a novel concept (the top-plate angle) to explore a potential breakthrough in the field. Particle Image Velocimetry (PIV) was employed to examine the flow morphology in a 35 mm mini-hydrocyclone with different roof angles (0°, 30°, 45°, and 60°), obtaining contour maps of axial and radial velocities and deriving streamline distributions through calculation. The results reveal that at identical angles, the streamline distribution within the cone-disk structure is more regular and organized. This indicates that integration cone-disk structure, the separation process becomes less susceptible to disturbance from vortices. Our findings identify a 30° inlet roof angle as the optimal configuration. Compared to the conventional design, this configuration reduces short-circuit flow by 2.34%. The optimized mini-hydrocyclone has been successfully implemented in a Methanol To Olefin (MTO) quench water treatment system, enabling efficient separation of fine particles and facilitating wastewater reclamation. Operational data confirm that the separation efficiency of the primary stage remains stable at 60-70%, while the secondary stage maintains an efficiency exceeding 80%.