Gas Compression With the Liquid Jet Pump

Abstract

The isothermal compression of a gas by a liquid jet in a mixing throat followed by secondary compression in a diffuser is described by a one dimensional model including frictional losses. Good theory-experiment agreement is shown; pump efficiencies can exceed 40 percent. Mixing throat and diffuser energy analyses are presented. The isothermal compression mechanism in the throat is related to momentum transfer while the diffuser process consists of a pistonlike compression of entrained gas bubbles by the continuous liquid medium. The efficiency of a liquid-jet gas pump depends primarily on the mixing loss. The mixing loss function, the throat compression ratio and the Mach number are developed as functions of the throat inlet velocity ratio v and the jet pump number n. A zero mixing loss criterion defines the theoretically possible region of pump operation. Design applications are discussed.