Effects of the slots on the performance of swirl-vane separator

Highlights: • For the cases studied, separation efficiency is in the range of 77.3–99.9%. • Separation efficiency depends mainly on the superficial velocity of water. • Influence of air superficial velocity on the pressure drop is dominant. • Water distribution is sensitive to both the air or water superficial velocity. • In a large range of operation conditions, usage of the slot is recommended. - Abstract: Swirl-vane separator is responsible for the separation of more than 80% of water liquid from steam in steam generator. It is vital to understand and predict the separation performance for the design purpose. To facilitate the understanding of separation process and provide data for the verification of CFD simulation, experiments on small-scale swirl-vane separators are carried out to study the effect of the slots on the separation performance. Tests were performed with the water superficial velocity ranging from 3.3 × 10−4 m/s to 1.4 × 10−2 m/s and the air superficial velocity in the range of 5.7–12.4 m/s. The separation efficiency in the studied cases is in the range of 77.3–99.9%. It depends mainly on the superficial velocity of water. For the pressure drop, the influence of air superficial velocity is dominant. Moreover, it is found that the distribution of the separated water is sensitive to both the water superficial velocity and the air superficial velocity. The fraction of water separated from the down-comer increases with the decrease in the air superficial velocity, while the opposite trend is observed for the fraction of water separated from the assistant barrel. Increasing the height of the slot, upper riser and orifice ring results in a larger fraction of water collected in the down-comer. By adding the tangential slots, separation efficiency is improved at a high water superficial velocity. To assure good separation performance in a large range of operation conditions, usage of the slot is recommended