Investigation of gas-bubbles separation from a liquid–gas mixture stream around a vertical 180° bend applied to gravity-driven separation using computing vision and computational fluid dynamics (CFD)

Separators are essential to many gas–liquid systems, especially to purge bubbles before the fluids enter specific equipment such as pumps or heat exchangers. Gravity, drag, buoyancy, and other forces exerted by the liquid over the bubbles are responsible for the separation process. A detailed analysis of the behavior of bubbles inside a separator is necessary to understand and improve the separation performance. This study combines high-speed video recording, object detection algorithm, and Computational Fluid Dynamic (CFD) simulation to understand the separation mechanism in a 180° bend separator. Bubble location and velocity have been acquired. Separated and unseparated bubbles have been identified to calculate the overall separation efficiency. The results have been utilized to validate a CFD model, which has been used to describe the flow further. Separation efficiency concerning bubble size and positions is also presented.