Effects of pressure control on droplet size distribution and flow regimes in gas–liquid cylindrical cyclone.

Marine production platforms and subsea production systems desperately need compact and highly efficient gas–liquid separators. The gas–liquid cylindrical cyclone (GLCC), which mainly utilizes gravitational and centrifugal forces to achieve separation, can be an superior choice. Herein, a pressure control scheme is proposed that allows the GLCC to realize fast and stable gas–liquid separation. The droplet size distributions measured by a Malvern RTSizer indicated that increasing the liquid superficial velocity only increased the distribution of small droplets at the inlet. The droplet size distribution of the down sampling at a high dimensionless pressure was larger than that at a low dimensionless pressure, which can be explained by the droplet migration model. As the dimensionless pressure decreased, four flow regimes were experimentally observed: annular flow, churn flow-stratified flow, falling droplets, and pure gas. Electrical resistance tomography measurement results indicated that better convergence of the bubbly filament was achieved at a higher dimensionless pressure. • A pressure control scheme was proposed to make the GLCC realize fast and stable gas-liquid separation. • The droplet size distributions in the GLCC were investigated in detail. • Four types of flow regimes were experimentally observed as dimensionless pressure decreased. • Better convergence of the bubbly filament was achieved at a higher dimensionless pressure. [ABSTRACT FROM AUTHOR]