Jet pumps: device, application, principle of operation. Water jet pump
The mechanisms of pumping and supplying water in pumps are most clearly expressed by the example of pumping systems. This principle involves the injection of fluid, which the pump can use for subsequent spraying. Actually, according to this scheme, jet pumps of liquid type work. They can be presented in the form of a conventional spray gun, and as an engineering structure serving large hydrological stations.
Constructions of water jet units
The water supply system in water jet pumps can be characterized as optimized. This can be seen at least in the execution of the standard design of such a unit. It is formed by a starting valve, a working nozzle, a branch pipe, guide nuts and protective devices that protect the entire body from rupture under high pressure.Depending on the modification, the number of individual elements, as well as their device, may vary. Much will be determined by the operational capabilities of the jet pump. The characteristic of the working potential of an average unit of this type is expressed by the ability to lift water by 50 m with a capacity of 3000 l / h. With such parameters, models of high household class or entry level professional level work. By the way, household models are often provided with a whole complex of filtering devices in the form of membranes that perform the cleaning function during water intake.
Principle of operation
Almost all water-jet units operate on the principle of kinetic energy, which is formed in the process of water coming out of the constricted nozzle. During operation, such systems provide the so-called dry suction, which creates a deep vacuum. It is important to note the pressure factor, without which the operation of the jet pump is impossible. The principle of operation in the context of the effect of pressure is determined by different fluid flow conditions on narrow and wide pipe sections.When the liquid passes from the narrowed section of the pipe to the wide one, the pressure rises and vice versa. In some ways, with such movements, a spring effect is created, which pushes water into the working circuit.
The dependence of pressure in the pipe on the speed explains the Bernoulli law. According to its formulation, jet pumps draw energy from the artificial constriction of pipes in nozzles and in separate technical areas, which allows adjusting both the pressure in the working medium and the flow rates.
Pump energy can be used for both discharge and suction of liquids. In this regard, emit injection and ejector units. In the first case, a guide nozzle is used without fail, which is connected to the target receiving device - that is, the tank where the water is scraped off. The main task of the injectors lies precisely in the fluid intake, although after performing this function, a vacuum is also formed. According to this principle, work jet fire pumps, which include the reception chamber, the nozzle with the throat, the diffuser and the main pipeline.The main task in the organization of the fire extinguishing process with a water jet unit will be to correctly set the parameters for the release of a liquid under pressure. As for the ejector pumps, they, on the contrary, are oriented towards the formation of a vacuum. That is, the characteristics with which the output of the selected fluid will be carried out are not so important in this case, although they will directly depend on the parameters of suction from a particular environment.
Spheres of application
Waterjet pump models are flexible in operation. And although ships are considered to be a target for their use, actual practice of application covers a much wider range of areas. For example, they are involved in the food industry, where it is important not only the ability of units to pump water, but also to mix it with different environments. Distributed and the use of a jet pump as part of sewer lines. In this case, use special stations that perform the pumping of water from the sand trap. This is the case when industrial stations are supplemented with filtering membranes.
But not only with water jet devices work.Depending on the characteristics of the fluid medium, they can also be used in working with viscous compositions, for example. In particular, the jet pump for oil production allows for the extraction of wells more than 1000 m deep. Another thing is that such transportation is impossible without the addition of water jet equipment with auxiliary transfer stations.
Advantages of pumps
First of all, the very principle of injection and ejector movement of fluid is optimal for servicing a variety of objects. It provides for the use of compact equipment, which also requires the connection of small-sized infrastructure. That is, small and large enterprises can be equipped with water jet stations without the risk of a significant reduction in the usable area. Also, since the water-jet pump does not have rotating and rubbing parts in the design, its physical reliability is also noted. The unit can be operated for a long time under heavy loads without requiring special maintenance. Resource reduction can take place only when working with aggressive media, but manufacturers in this case provide the design with special protective materials.
Like all simplified designs, water-jet stations are not capable of providing high performance, therefore their efficiency at best reaches 70%. In addition, they require a constant power connection for the primary fluid supply to the nozzle. Another disadvantage that jet pumps differ in is their low autonomy. The principle of operation implies a dependence on environmental conditions that must be created by third-party resources - and this is another item in the cost of maintaining the function of this equipment.
Features of operation
It is possible to integrate the pump into the working infrastructure only after an analysis has been made of the compatibility of the unit with the serviced liquid. With regard to work activities, the list of tasks of working personnel will include maintaining a sufficient amount of fluid in the pump channel and ensuring an adequate level of safety. Usually jet pumps are equipped with a wide range of measuring sensors and instruments that show the level of pressure, the speed of movement of the working medium, temperature, etc.The user must track these values, comparing them with the recommended. Stopping the unit starts with the valve closing. Next, the fore-vacuum transfer of the remaining liquid and the physical detachment of the structure are performed.
Inkjet transfer stations have many varieties. In this case, considered an example of units that work with liquid media. But there are also whole groups of modifications focused on servicing steam and gas mixtures. Especially the ejector water jet pump is effective in working with steam, allowing you to fine tune the design for specific tasks. Less common are the combined models of such pumps. This is due to the fact that the surfaces of the material of the same nozzle are initially developed under the properties of the served medium. Therefore, even in certain categories of models designed specifically for liquid or gaseous media, it is difficult to find universal designs. The only exception is pumps that work with water and similar media. In other cases, units with additional accessories are selected purposefully for the properties of a particular liquid, vapor or gas.And this is not to mention the accounting characteristics of the circulation of the carrier in the serviced infrastructure.