Jet pumps comprise one of types of continuous flow friction pumps. These units have no rotating parts; so, liquid moves due to friction between liquid itself and the operating liquid flows. The primary purpose of jet pumps is to move viscous liquids and gases by kinetic energy produced by steam or water.
In water-jet pumps, water is used as operating liquid. It is discharged from the nozzle to the mixing chamber at very high speed; then, it flows into the diffuser. Within the scope of the process, operating liquid entrains pumped liquid by friction force.
Liquid is delivered to the mixing chamber from the suction line due to pressure difference in the mixing chamber itself and in the diffuser. Flow speed drops and pressure energy grows in the diffuser. Due to these processes, substance is delivered by the head into the discharge pipe.
Steam-jet pumps are necessary when pumped substance must be prevented from mixing with water resulting from condensation (i.e. when water is delivered into steam boilers).
Jet pumps are classified into three types in accordance with the types of substances moved by pumps and the types of operating liquids used by pumps:
The design of jet pumps is simple; as a result, they require virtually no repair and are highly reliable. Their operation principle is based on movement of liquid, steam or gas through a pipe with a tapered nozzle (due to this design, liquid moves at high speed). Pressure in the supply chamber is kept below atmospheric pressure. Suction is carried out from the pipeline connected with the chamber. Liquids are subsequently combined and mixed in the second chamber; the resulting mixture is delivered into the diffusor and, subsequently, into the reservoir.
The most significant parameter of a jet pump is the suction factor calculated as operating liquid volume to pumped substance volume ratio. These pumps have low efficiency; however, there are absolutely no alternatives for these pumps in some applications. For example, jet pumps are used in food industry to pump liquids from reservoirs when other types of pumping units are inapplicable.
Jet pumps are frequently used as additional equipment, because they can easily be installed in combination with other types of pumps:
Also, jet pumps are used in applications for which the impeller pumps are ineffective (e.g. to pump polluted or corrosive substances) and in integrated systems with impeller pumps, to improve operation efficiency.
As a rule, these pumps are installed in series with each other; installation in parallel is very rare. These pumping units are available with adjustable nozzle, making their characteristics controllable within the specified range.
Jet pumps can be used, although rarely, with high-pressure reservoirs containing active substance. These units can be also considered as parts of heat pumps, because, when steam is discharged under low pressure, temperature drops in the nozzle, and when the discharge pressure is high, the diffuser is heated. Due to this property, jet pumps are applicable in conditioning systems.
The major advantages of jet pumps, as compared with other types of pumping apparatus, are as follows: simple design; long service life; reliability; low vulnerability to corrosive substances. These advantages are largely due to the pump design free of rotating parts. Jet pumps have small dimensions, small volume and low weight. Operational expenses for these pumps are minimal.
Great variety of jet pump design versions is available; as a result, they are widely used in many different branches of industry, both as separate units and as components of other pumping units. There are no alternatives for these pumps for operations with alkalis and acids, with liquids containing fuel oil and admixtures, and with salts. These pumps are used in applications where different types of media must be metered, mixed and dissolved. Jet pumps demonstrate reliable operation in emergency situations involving water supply shutdown at industrial facilities, prevention of cavitation, pumping of hazardous liquids and processes at reactors.
We are convinced that our company ENCE GmbH will become your reliable and efficient distributor (authorized representative) of your jet pumps in the Russian market.