Effect of drainage channel on separation performance of swirl-vane separator

Swirl-vane separator in nuclear reactors removes liquid from gas by centrifugal force. Since liquid film is accumulated on the wall, drainage channels are designed to remove liquid film in time and reduce secondary droplet entrainment. Euler-Euler multiphase numerical model and Realizable k-epsilon turbulence model are devel-oped to investigate the effect of drainage channels. The results indicate separation efficiency is improved by removing water through drainage channels at low inlet gas velocity, while reverse gas flow from down-comer to riser through drainage channels pushes water near wall to the axis of riser, deteriorating separation at high inlet gas velocity. Moreover, the effect of channel area, size, shape and arrangement are analyzed. Separation per-formance is most sensitive to drainage channel arrangement compared to size and shape. Evenly distributing drainage channels over a wide range of wall benefits separation of water and reduces reverse gas flow.

Automated summary

This study investigates the effect of drainage channels on the separation efficiency of swirl-vane separators in nuclear reactors. It is found that using drainage channels can improve separation efficiency at low gas velocities, but reverse gas flow from down-comer to riser through these channels can deteriorate separation at high gas velocities. The arrangement of drainage channels has the greatest impact on separation performance compared to their size and shape.