Experimental Study of Droplets Collision and Bag Breaking in Rotating Gas Flow Field

In swirl-vane separators, the liquid phase is separated from the rotating gas flow under the action of centrifugal force. The droplets are carried by the rotating gas flow to the wall of the separator. In this paper, the phenomenon of a single droplet hitting on a stationary droplet on the wall in the rotating flow field is recorded by using a high-speed camera. Different types of droplet collisions appear as the inlet airflow velocity increases from 4 m/s to 4.8 m/s. Results show that the binary droplet impacts in the rotating flow field occur in asymmetric outcomes such as coalescence, finger spreading, finger breaking and splashing with the increase of the Weber number. The spiral characteristic of the rotating flow field leads to the asymmetry of the droplet collision. The bag breaking occurs in the rotating flow field. The number of droplets of bag breaking and breaking time are increased with Weber number increasing. This study provides basic characteristics for the impact of binary droplets in the rotating flow field and bag breaking, as well as improves the understanding of the separation efficiency mechanism of the gas-liquid separator.