UU-type parallel mini-hydrocyclone group separation of fine particles from methanol-to-olefin industrial wastewater

Mini-hydrocyclones are used to separate fine particles from wastewater and are typically used in a parallel configuration to enhance wastewater treatment. Based on a mini-hydrocyclone group with a UU-type parallel configuration, a 300-times scaled-up parallel unit of mini-hydrocyclones was created and then used in single-phase experiments to study the distribution of flow and pressure drop, as well as in liquid-solid two-phase experiments to study separation performance. Single-phase experiments demonstrated the flow and pressure drop tended to decrease in an axial direction, but were relatively uniform in the circumferential direction, which is consistent with theoretical calculations. Two-phase experiments revealed that the separation efficiency decreased along the axial direction and, for 1.6 micron particles, the average separation efficiency reached 79.4%. Finally, the mini-hydrocyclone group was used to treat wastewater from the industrially important methanol-to olefin conversion, where they displayed an average separation efficiency of 77.2%. This value is similar to the experimental results, indicating that the mini-hydrocyclone group has good applicability in wastewater treatment.