Research on the particle circulation flow and classification performance of multi-stage cylindrical hydrocyclones

The cylindrical hydrocyclone is widely used for coarse particle classification to suppress the misplaced fine particles in the underflow. Nevertheless, the unique flat bottom structure generates particle circulation flow, causing the misplacement of coarse particles in the overflow. A multi-stage cylindrical hydrocyclone is designed to regulate the particle circulation flow by shortening the particle radial settling distance. The particle circulation flow and classification performance of the cylindrical hydrocyclone and multi-stage cylindrical hydrocyclone are investigated by numerical simulations and physical tests. The numerical test results demonstrate that the multi-stage cylindrical hydrocyclone strengthens the circulation flow of 59.5 μm particles and 89 μm particles, and limits the circulation flow of 150 μm particles, increasing the enrichment ratio of 59.5 μm particles and 89 μm particles, reducing the enrichment ratio of 150 μm particles. The experimental results indicate that the multi-stage cylindrical hydrocyclone suppresses particle misplacement in the overflow and underflow with superior classification efficiency, sharper separation accuracy, smaller cut size, and higher solids yields.