water vapor jet pump structure and working principle
The internal components of water vapor jet pump are mainly composed of Laval nozzle and diffuser. The structure of single-stage steam jet pump is shown in the figure, and the structure of other stages is basically the same.
Its working process can be divided into three stages: adiabatic expansion stage, mixing stage and compression stage.
In the adiabatic expansion stage, after the working steam passes through the converging nozzle, the pressure energy is converted into the velocity energy and enters the diffuser at a very high speed. At the same time, the pressure of the working steam drops at the nozzle outlet, forming a vacuum to suck in the extracted gas;
In the mixing stage, the extracted gas enters into the diffuser. In the diffuser, the steam and the extracted gas collide and mix for energy exchange, and the mixture is completed at the throat of the diffuser, and the two gases reach the same speed;
In the compression stage, after passing through the throat of the diffuser, the mixture velocity decreases and the pressure rises further. At the outlet of the diffuser, the air pressure reaches the atmospheric pressure or the inlet pressure of the next stage injector, and the extracted gas is discharged.
