The working fluid of the jet pump can be gas (air or steam) and liquid. Common water vapor jet pumps, air jet pumps and water jet pumps. There is also a jet pump that uses oil as a medium, namely an oil diffusion pump and an oil booster pump, which are the main equipment used to obtain high vacuum or ultra high vacuum.
Steam jet pump
The water vapor jet pump is a jet vacuum pump that uses water vapor as a working medium and can directly exhaust the atmosphere. This kind of pump starts quickly, occupies a small area, has a wide working pressure range, and has a large pumping capacity. It can remove dust, corrosive, flammable and explosive gases. It is more economical to use the remaining or abandoned steam. The shortcomings of this kind of pump are high civil engineering investment (some installation height needs more than 10m) and large cooling water consumption. The compression ratio of single-stage steam jet pumps generally does not exceed 10.
Air jet pump
Air jet pumps use compressed air or atmospheric air as the working medium. The airflow generates low pressure at the nozzle outlet to suck air or other gas, and then compresses it and discharges it. According to the working medium is high-pressure air or atmospheric pressure air, it is divided into general air jet pump and atmospheric jet pump. The air jet pump has a large working medium consumption and must have an air compressor with a large capacity. Most air jet pumps are single stage.
Water jet pump
When the required vacuum is not too high, a certain pressure of water can be used as a working fluid water jet pump to create a vacuum. The speed of water spray is usually around 15-30m/s. It belongs to rough vacuum equipment. Because the water jet pump has the dual function of generating vacuum and condensing steam, it is widely used.
Types and applications of jet pumps
