Experimental study of swirling flow pattern at the swirler outlet using a Wire-Mesh sensor

Abstract

Entrained droplets and flow pattern change adversely affects separation performance of swirl-vane separators. Investigating gas–liquid distribution at swirler outlet, an experiment was conducted using a wire-mesh sensor positioned. Air and liquid superficial velocities ranged from 8.3 to 25.6 m/s and 0.1 to 1.4 m/s, respectively, covering swirling annular and swirling churn flow at swirler outlet. In swirling annular flow, liquid phase primarily exists as a stable thin film which facilitates efficient separation. In swirling churn flow, wall liquid film has unstable large amplitude disturbance waves. Disrupting liquid film leads to entrained droplets forming in gas center, increasing separation distance and hindering gas–liquid separation. The transition boundary from swirling churn to swirling annular is crucial. Increasing swirler angle shifts the transition boundary towards higher gas velocity at the same liquid velocity. A theoretical model based on interfacial shear stress and gas core blockage predicts the flow pattern transition at swirler outlet.