Numerical and experimental investigations of the effects of the breakup of oil droplets on the performance of oil–gas cyclone separators in oil-injected compressor systems

• The results showed that the breakup of oil droplets occurred in the separation process.
• The breakup of oil droplets influenced certainly the separation efficiency.
• The inlet velocity determined the possibility of the breakup of oil droplets.

A numerical simulation was conducted of the dynamic trajectories and the separation performance of oil droplets, with a focus on the breakup of oil droplets in an oil–gas cyclone separator. The separation efficiency was also studied experimentally, and the oil droplets' diameter distributions before and after the separator were measured with a Malvern particle size analyser to verify the simulation model. Both the experimental and simulation results showed that the breakup of oil droplets occurred in the separation process, clearly influencing the separation efficiency. In addition, the results indicated that inlet velocity played an important role in separation efficiency, as it not only significantly affected the tangential velocity inside the separator, but also determined the possibility and degree of the breakup of oil droplets.