Two-phase swirling flow in the barrel of a steam separator

MIKA Takeshi, MATSUBAYASHI Toshiki, HOSOKAWA Shigeo, and TOMIYAMA Akio

Department of Mechanical Engineering, Faculty of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan (tomiyama@mech.kobe-u.ac.jp)

Abstract: A downscaled model of a steam separator was used to understand the characteristics of swirling flow after passing through the first pick-off ring (POR). Main conclusions obtained were as follows: (1) At high liquid volume fluxes, many droplets are entrained in the gas core at the downstream edge of the POR. The liquid film thickness above the POR gradually increases due to deposition and accumulation of droplets. (2) At low liquid volume fluxes, water accumulates just behind the POR. (3) A smooth rear edge on the first POR reduces the entrainment of droplets and increases separation performance at the second POR especially under high liquid volume flux conditions.
Keyword: steam separator; two-phase flow; swirling flow; pick-off ring; boiling water reactor