Performance of a Model In-Line Vortex Separator

Abstract

A scale model of the Ohaaki vortex separator was tested using air and water to simulate the turbine exhaust wet steam. The model separator had a separation efficiency of between 75% and 98% for the ranges of air and water flow rates tested. A small proportion of the injected water vaporized in the warm air causing some water to be unavailable for separation. However, this is to water flashing due to pressure drop in steam-water flow. The model tests showed that gravity settling rather than centrifugal action appeared to predominate the separating mechanism. The presence of the helicoid vanes appeared to cause water droplets to reentrain in the air stream rather than centrifuged them onto the wall of the separator. Further tests are recommended with the helicoid vanes removed and the vortex separator replaced by a model Ohaaki drain pot.