Investigation on the oil-gas separation efficiency considering oil droplets breakup and collision in a swirling flow

In this study, the oil droplets separation process in a swirling flow was investigated using numerical simulations and verification experiments. Numerical models were established to investigate the effects that the collision and breakup of droplets and the collision between droplets and wall on separation efficiency, respectively. The separation efficiencies were calculated using different models under various inlet velocities, from 10 to 18 m/s. The simulated results showed that droplets colliding could improve the separation efficiencies with up to 22.4% increments at the 10 m/s inlet velocity for droplets with a diameter of 10 μm. The oil-gas separation efficiency was reduced up to 17.4% due to the oil droplet-wall interaction in swirling flow when the simulation model involved droplet-wall collisions. The simulated separation efficiencies showed little change when oil droplet breakups were considered in the model under different inlet velocities and droplet diameters. A test rig was built to validate the simulation results. It showed good agreement between the experimental data and simulated results. Thus, the numerical simulation model could be used to predict separation performance and understand the separation process in a swirling flow.