Two stage ejector as a pre-stage of the water ring vacuum pump

Abstract

A supersonic gas ejector in conjunction with a liquid ring vacuum pump is used for creating and maintaining a vacuum in a chamber for technological purposes. In this paper, the authors submit an overview of the problematics of suction pressure reduction with a supersonic gas ejector used as a pre-stage of a liquid ring vacuum pump. This system has also the function of a cavitation protection due to the higher pressure present at the suction throat of the vacuum pump. A part of this paper is devoted to the governing equations used at the definition of the flow through an ejector. The CFD analysis of the problem was implemented with the package Fluent in 2 dimensions using the axisymmetric approach. The parts of the physical model were printed on a STRATASYS 3D printer, or were cast from technical resin. The experimental studies are then carried out in our own laboratory for validation purposes.