Gas liquid separation within a novel axial flow cyclone separator

摘要

Cyclone separators have been described in detail and, although substantial research has beenperformed on solid / gas devices, the use of cyclones for gas / liquid separation has beencomparatively ignored; this is particularly true for higher concentrations of liquid and fordegassing applications. Consequently no generic models are available which will predictseparation efficiency or pressure drop for all designs of cyclone.A novel design of axial flow cyclone called WELLSEP was examined for the purpose ofdegassing. This design was not believed to be optimal and no design criteria or performanceprediction models were available for it. An experimental programme was therefore producedand executed to investigate changes in geometry and the affect of fluid dynamics. Changes tothe length, vortex finder and swirl generator were examined first and then one design wasselected and tested over a number of liquid flow rates, Gas Void Fractions (GVFs) and liquidextractions.Data was collected from the experiments which assisted in the development of semi-empiricalmodels for the prediction of pressure drop and separation efficiency. These models could beused in the design of WELLSEP.Geometric and fluid dynamics changes have both been shown to influence the performance ofthe tested cyclone. The principal conclusions that have been drawn from this research are:" Of the tested designs, the design based upon a 30mm vortex finder diameter, settlingchamber length of three times the diameter of the cyclone and a four start helix gave theoptimum separation efficiency over the greatest range of conditions.0 The separation efficiency is affected by the superficial liquid velocity and the liquidextraction but not the GVF." The dimensionless pressure drop coefficient (Euler number) is a function of liquidextraction and GVF. It may also be a function of the superficial liquid velocity but it is unproven by this research.