A Comprehensive Review of Liquid Ring Vacuum Pumps and Compressors for Improving Global Efficiency and Energy Saving

Abstract

Liquid ring vacuum pumps and compressors are
mechanical positive displacement turbomachines that can
operate in the mode of both vacuum compressor and vacuum
pump. They are widely used in the fields of filtration, cryogenic,
reaction, gas injection, condensation, evaporation, and drying.
Despite their low performance, they have many advantages such
as
low
costs,
simplicity,
reliability,
improve suction
characteristics, and in many cases, can provide a more efficient
option. Improving efficiency is the key to decrease energy
consumption and costs. The article analyzed and evaluated the
previous investigations regarding these machines with a focus on
challenges of improving efficiency, advances in numerical
simulation, and experiments to afford beneficial insight on future
research and next steps. The study revealed that the thermal
interaction and the cavitation phenomenon are among the most
important problems that require further research.