Vitaly V. Kharkov,¹ Nailya Z. Dubkova,¹ Maxim G. Kuznetsov<sup>1,2

1</sup>Kazan National Research Technological University (Russian Federation)
²Kazan State Agrarian University (Russian Federation)

Abstract

This study addresses a critical challenge in the oil and gas, chemical, and power industries by experimentally investigating the effect of liquid viscosity on droplet entrainment in a gas-liquid separator equipped with an axial swirl-vane. A novel separator design featuring a combined final separation unit, which integrates a perforated sleeve with an inertial toroidal splitter, is proposed and analyzed. The performance was examined with liquid kinematic viscosities ranging from 1 to 50 cSt. Experimental studies were conducted on a 100 mm diameter separator with a vane inclination angle of 45°, varying gas flow rates from 0.115 to 0.180 m³/s and liquid mass flow rates from 25 to 150 kg/h. A key quantitative relationship was established, showing that increasing liquid viscosity leads to a 2.3 to 3.7-fold rise in droplet entrainment, with the most pronounced effect observed at viscosities up to 15 cSt. Based on the data, an empirical formula was derived for predicting liquid entrainment as a function of the kinematic viscosity ratio and phase load. The combined separation unit was more effective at reducing droplet entrainment than conventional designs. Consequently, operating separators at higher gas Reynolds numbers is recommended to mitigate the adverse effects of high liquid viscosity. These results show that optimizing the separator's design and operation is important for handling high-viscosity liquids, as this can improve efficiency and lower costs in industrial use.