Injection pump's working fluid is a gas (air or steam) and liquids. Common water vapor injection pump, air injection pump and water injection pumps. There is also oil is medium in a Jet pump, oil diffusion pump and booster pump is used to obtain high vacuum or ultra high vacuum equipment.
Steam jet pump
Steam jet pump for water vapor as the working medium, can direct air exhaust of a Jet pump. The pump starting fast, covering an area of small, wide range of working pressure, suction, removing dust, corrosive and flammable and explosive gas. If it can use surplus or waste steam is more economical. The disadvantage of this type of pump is construction investment (mounting height needed above 10m) and consumption of cooling water. Single-stage steam ejector pump the compression ratio does not exceed 10.
Air injection pump
Air injection pump is to use compressed air or atmospheric air as working fluid. Generated by air flow at the nozzle outlet low pressure to draw air or other gases, and then discharged to compress it. According to the working medium is high pressure air or atmospheric air, divided into General and atmospheric air injection pump injection pump. Medium consumption of the air injection pump, and must have a capacity of air compressors. General air most of Jet pumps are single-stage.
Water jet pump
When asked when the vacuum level is not too high, you can use water as a working fluid pressure water injection pump to produce the vacuum. Water jet velocity at about 15-30m/s. It belongs to the rough vacuum equipment. Water injection pumps have a dual role of creating a vacuum and condensing the steam, so is widely applied.