A design tool for optimising axial liquid–liquid hydrocyclones

A numerical model has been developed (HAAS), that predicts the velocity field in axis-symmetric flows with high swirl- and Reynolds numbers in cyclone geometries, together with trajectories of particles released in this field. Since HAAS is a kinematic model based on integrals of the flow field, it is much faster than CFD. Using HAAS, a prototype de-oiling hydrocyclone separator, the DelftCyclone, was developed. s paper HAAS is explained, and its predicted results are compared with those obtained from detailed simulations using a commercial CFD code: Fluent (V6.0.12), and with results from laboratory experiments. The pressure drop and flow field from HAAS compare quantitatively well with those from Fluent; however, compared to laboratory experiments, both models overestimate the pressure drop by some 80%. The predicted separation efficiencies are trendwise correct, but both overestimate, partly because turbulent dispersion was ignored. concluded that the HAAS model is very time-efficient in the design of axial hydrocyclones, and because of its speed it can be used as an interactive tool with real-time output. On the other hand, more realistic flow simulations are valuable for geometry refinement, because they can resolve details that are not included in the coarse HAAS model.