Particle Collection and Concentration for Cyclone Concentrators

Four cyclone concentrators were designed and fabricated to compare their particle separation and concentration behavior, such as the major, minor, outlet, and wall deposition fractions. Two of the cyclone concentrators were the conventional type, with the minor flow tube connected to the particle outlet at the bottom of the cyclone. The others were modified cyclone concentrators with a gap between the particle outlet at the bottom of the cyclone and the minor flow tube. The modified cyclone concentrators had different particle outlet and minor tube diameters, with variable minor tube heights. The particle number fraction of the minor flow for the conventional cyclone concentrator increased and had wider U-shaped curves, in the large particle size range, as the particle outlet diameter increased. In addition, the gap between the particle outlet and minor flow tube of modified cyclone concentrator had an adverse effect on the particle concentration ability of the cyclone concentrator with a small minor tube diameter, in that the wall deposition and particle fraction of the minor flow were increased and decreased, respectively. However, the modified cyclone concentrator with a large minor flow was a better particle concentrator because the gap offered a space for the particles collected on the cyclone wall to gather, preventing the particles from going along the minor flow, especially with high particle concentrations in the inflow.