Britannica
Sources used in this answer
How does a steam ejector create a vacuum?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
vacuum technology
Diagram of a McLeod gauge.
A steam ejector creates a vacuum by utilizing the high-velocity energy of steam to entrain and compress gases. The process functions through the following steps:
- Momentum Transfer: High-velocity steam enters the pump body, where it transfers its momentum to the gas being drawn in from the inlet line.1
- Entrainment: This action creates a suction effect, effectively pulling the gas into the steam stream.1
- Compression: The resulting mixture of steam and gas passes through a venturi tube known as a diffuser. Within this component, the kinetic energy of the mixture is converted into pressure energy.1
- Discharge: By converting this energy, the ejector compresses the gas from a low-pressure state to a higher pressure, allowing it to be discharged.1
Because vacuum pumps function by taking in gas at pressures below atmospheric pressure and discharging it at atmospheric levels, steam ejectors are highly effective for handling large volumes of vapors and gases in industrial applications.1