Almost everyone who has ever been directly involved in organizing the arrangement of an autonomous-independent water supply has periodically encountered problems regarding the insufficient level of water supplied by the suction pump.
In the subject of physics, we definitely know and understand that such a factor as pressure is capable of supplying liquid from a maximum depth of nine meters, but in fact this figure is much less, which in reality is about seven and sometimes five meters of full supply.
A station that can increase the pressure of the water flow will solve the problem. Specialized equipment designed for such purposes is produced modern industry, which is part of the pumping stations.
From the article presented to your attention, you will learn in detail about the operating principles of such specialized equipment as a station with an ejector, as well as all the nuances and aspects regarding their use. Additionally, methods for possible production of such equipment on your own will be considered, with appropriate instructions and recommendations, thanks to which you can achieve this goal.
Device. Operating principle
An ejector is essentially a device that transfers energy from one more mobile medium to another, which is less mobile. In the tapering sections of the unit, a special zone of lower pressure is formed, which thus provokes the suction of additional medium. Thus, it is possible to move and move away from suction points, due to the interaction of the original environment.
Units equipped with an internal format ejector are intended directly for specialized pumping of liquids from relatively shallow wells, the depth of which does not exceed eight meters, as well as various specialized storage tanks or reservoirs.
Directly distinctive feature Such interaction is precisely to capture liquid that is located at a lower level from the pipe. Based on this, preliminary filling of the unit with water will be required. The working wheel will pump liquid, which will redirect it to the ejector, resulting in the formation of an ejection jet.
It will move through a specialized tube and accelerate. Naturally, the pressure will decrease. Thanks to this effect, it will also decrease inside the suction chamber.
One of the varieties of such surface installation units is a pumping station with an ejector. They differ in that the external element is immersed in the water supply source. As a rule, the scope of application of such devices is similar to their analogues. The definite difference lies in the different depths of use and application.
Pumping station with remote ejectorManufacturing
It is quite possible to produce a fairly simple device-unit independently. This will require some parts, such as a tee of a specialized diameter and a fitting that will be located inside it. The correct length ratio must be observed, which should not be more or less, which will not allow such a device to function normally. For fastening you will need a special adapter equipped with corners, which will allow you to create the desired rotation.
The creation process involves several specific points, which includes the process of preparing the required fitting itself. Part of a special 6-sided sample should be ground, which will allow it to be made into a special cone with a base smaller than external thread in diameter. After which the deformed part should be corrected with a specialized thread-cutting tool.
The fitting must be screwed all the way into the tee piece. When connecting, be very careful to observe the length ratio, which is sufficient important factor. Be sure to seal the connection with any available sealant.
Check the ratio of the parts being manufactured, and then from pre-prepared samples you should organize a specialized adapter, which is designed for installation on the pipe.
A well-assembled station will ensure fairly long and trouble-free operation due to its simple design, but, naturally, you must be extremely precise in manufacturing. If you don’t really want to engage in such production, then you can simply purchase it in specialized stores, where a pumping station is always available for free sale.
Stations with a built-in ejector - how to use themThe station is used to increase the pressure, which will also eliminate the possibility of premature failure of the unit that provides the supply, since idling may occur. The presence of such an element in the system will exclude it, which is why it is recommended for mandatory integration into the system, regardless of the possible depth of the source.
Timely equipping a station with an ejector will save you from additional costs and possible nervousness in case of possible failure of more expensive system equipment, which it will simply prevent, ensuring full and uninterrupted functionality for a long time.
Almost anywhere a private house or a cottage can be equipped autonomous water supply from a borehole or well. Typically, a pump is used to pump water. If the depth of the aquifer is less than 7 meters, then there will be no problems with choosing a pump. You can choose any unit of suitable power and performance. However, such products will not be able to lift water from deeper hydraulic structures. To lift water from great depths, it is necessary to use an ejector to pumping station.
To understand why you need pump ejector, imagine that we will improve with our own hands a conventional submersible pump for lifting water from great depths. Certain limitations for the operation of a conventional pumping station will be created by water pressure, atmospheric pressure and the strength of the structural parts of the pump. During the modification, a conventional submersible pump will become much heavier and its dimensions will increase. As a result, such a unit will simply become difficult to operate. In addition, the amount of electricity consumed will increase significantly.
To avoid such problems, it is necessary to use additional parts to facilitate pumping water to a considerable height. It is the ejector that pushes the water towards the surface and facilitates its rise. This is a fairly simple device that you can install yourself.
To understand what an ejector is and to know its operating principle, it is necessary to study the purpose of the main components of the device. It consists of the following structural parts:
You can install the ejector yourself. It is mounted in a pipeline laid from the well to the pumping device. The principle of operation of the unit is such that part of the liquid raised to the surface is lowered back into hydraulic structure to the ejector. Thus, a recirculation line is formed. During such work, water bursts out of the nozzle at a powerful speed and takes some of the liquid out of the well, creating additional vacuum in the pipes. Thanks to this operating principle, pumping equipment spends much less power lifting water from great depths.
To regulate the volume of liquid returning back to the system, a special valve is installed on the recirculation line. Thanks to it, you can regulate the efficiency of the entire system.
It is important to know: part of the water that is not used in the recirculation system goes to the consumer. It is by these volumes that productivity is judged. pumping equipment.
Advantages of ejector type pumps:
There are two types of ejector type pump:
The choice of one or another type of ejector layout is determined by the requirements for pumping equipment. To suck air from different containers, another type of such units is used - an air ejector. It has a slightly different operating principle. In our article we will study devices to facilitate pumping water.
Pumping equipment with a built-in ejector has more compact dimensions. In addition, the creation of liquid pressure and its intake for recirculation occurs inside the pumping equipment. This pump uses a more powerful motor that can recirculate liquid.
The advantages of this design solution:
Among the disadvantages it is worth noting the following:
For execution outdoor installation ejector, next to the pumping equipment, it is necessary to equip a tank into which water should be collected. In this container the working pressure and the necessary vacuum will be created to facilitate the functioning of the pumping equipment. The ejector device itself is connected to that part of the pipeline that is immersed in the well. In this regard, there are restrictions on the diameter of the pipeline.
Advantages of a remote ejector:
Disadvantages of the external location of the ejector device:
As a rule, the installation of pumping equipment with a built-in ejector is no different from the traditional installation of a conventional pump. To do this, it is enough to connect the pump inlet pipe to the pipeline coming from the well. A pressure line is also installed, a hydraulic accumulator and the necessary automation are installed.
In systems with an external ejector, the equipment is connected in the following sequence:
If required, a control valve is installed in the recirculation pipeline. This additional device it is simply necessary for wells in which the water level is above the calculated level of liquid for pumping equipment. Thanks to this valve, it is possible to reduce the pressure in the ejector and cause a rise in pressure in the water supply system. Some models are equipped with a built-in control valve.
It’s worth knowing: usually the adjustment method and location of the valve are specified in the instructions supplied with the unit.
Pumping stations are in high demand among the population for individual water supply due to their versatility and reasonable cost; their only serious drawback is the small depth of water intake, not exceeding 9 meters. For this problem, there is a simple engineering solution based on Bernoulli’s physical law - an ejector for a pumping station; with a similar device, a surface electric pump is capable of sucking water from deep sources at a distance of tens of meters from the surface of the earth.
This device, when used with a surface pump, is useful in cases where the water level of the source with which it was previously worked surface pump, for some reason fell (siltation of the well and borehole, intensive water intake).
It should be understood that the price of obtaining a high suction depth is the low efficiency of the electric pump, because part of the raised water is sent back to the suction pipe to increase the kinetic energy of the input flow. This factor hinders the use of surface ejector electric pumps for lifting water from great depths - for these purposes, wells are drilled and submersible pumps are used, the pressure of which in domestic use can reach up to 200 m.
Rice. 1 Design and appearance of an ejector for a water station
An ejector is a device in which two media are combined in a mixing chamber, one of them moves at high speed and is fed through a narrowed nozzle, and the second fills the chamber naturally. The flow leaving the nozzle with acceleration transfers its kinetic energy to the moving medium, which is then carried away from the suction point. Also, in the area at the exit of the narrow section of the nozzle, a reduced pressure is created - this leads to the fact that the moved medium is simultaneously sucked in by the ejector.
The moving and accelerating medium can have different physical states; in jet pumps, air or steam is supplied through a narrow nozzle, which heats the water flow and pushes it out at high speed.
Rice. 2 Ejector design The ejector design is no different high complexity, its main elements are:
Rice. 3 Centrifugal pump - internal structure The use of an ejector in domestic pumping stations is justified only in exceptional cases - when used, depending on the immersion depth of the suction pipe, the efficiency drops by 50 - 70%, which leads to unjustified waste of electricity. Therefore, to draw water from great depths, everyone uses submersible electric pumps and drills special wells for them. This is also more effective because the efficiency submersible pumps higher than surface ones, which spend part of their energy on suction and lifting the water column to the impeller (ratio 65% to 50%).
On the pumping equipment market, there are still surface centrifugal electric pumps with built-in or remote ejectors, and to answer the question of why an ejector is needed in a pumping station, you should consider options for its use:
Rice. 4 Ejector pumping stations The pumping station is a monoblock structure, the main part of which is a centrifugal electric pump located above the hydraulic accumulator tank, its required elements- pressure switch and pressure gauge mounted on a five-inlet fitting.
The principle of operation of a centrifugal electric pump is to supply the sucked liquid to the center of the impeller with blades, which, when rotated, due to centrifugal force, push it out through the side outlet pipe.
Standard centrifugal pump It has an inlet hole in the center of the hydraulic compartment and an outlet hole located perpendicular to its axis in the side, but there are pumps with a different design.
Rice. 5 Built-in ejector - diagram Pumping stations with a built-in ejector include a centrifugal electric pump, in the hydraulic part of which an ejector unit is located. The principle of operation of such a system is quite simple - the sucked water enters a centrifugal impeller, which throws it out through the side pipe. At the same time, part of the liquid, to which the rotation of the wheel has given kinetic energy, is directed through the ejector channel into the nozzle and is pushed out of it under pressure. The flow, accelerated due to the narrowed part of the nozzle, mixes with the transported one, transferring its energy to it, and at the same time drawing in due to low blood pressure at the exit. Thus, a significant increase in the immersion depth of the suction pipe is achieved, which in some models reaches 50 meters.
A distinctive feature of such pumps is the inlet, offset relative to the central axis (in conventional centrifugal electric pumps, such an arrangement is also not uncommon); such units are very rare in pumping stations due to the reasons given above (low efficiency).
Rice. 6 Electric pump design with built-in ejector A pumping station with a remote ejector has a significant advantage over equipment with a built-in ejector unit - it can operate in normal mode, lifting water from a depth of no more than 9 meters, and if necessary, you can always connect a device to it to increase the suction depth.
For this purpose, in the hydraulic part of the housing there are two holes of different diameters with standard sizes 1 1/2 and 1 inch, a pressure pipeline is connected to the larger one, and a recirculation pipeline is connected to the second, supplying water to the ejector nozzle. The ejector unit itself is placed in the water intake source along with the pipelines. Since without supplying liquid to the ejector it will not rise from a great depth, before starting work the entire system is filled with water.
By appearance Electric pumps with a remote ejector differ from standard models by the presence of two adjacent holes in the hydraulic compartment of the housing. A pumping station with an external ejector is produced by many domestic and foreign manufacturers, the most famous is the Marina model from the Italian company Speroni; other Italians are also often found on the market: Aquatica, Quattro Elementi, domestic Unipump.
Rice. 7 Station with a remote ejector and its connection When a standard pumping station stops suctioning water during operation due to a decrease in the water surface, it can be lowered by digging a hole in the ground of the required depth - there are no other ways to increase the suction depth. There is no point in making a homemade ejector according to any drawings, purchasing and installing it - the part cannot be connected to a housing that has one inlet for the pressure pipeline instead of the two required for the operation of the ejector unit.
If you purchased an ejector pumping station, but the unit was lost or broken, you can make an ejector with your own hands from parts of plumbing fixtures and fittings.
A similar design diagram is shown in Fig. 8, its main components are:
Before assembly, grind the hexagonal part of the fitting to a cone-shaped state, shorten it to the required length or lengthen it by cutting a vinyl chloride tube. Afterwards, the entire structure is assembled, screwing in the fitting first, and then the remaining parts with a seal. threaded connections flax, sanitary thread, FUM tape.
Rice. 8 Homemade ejector Water pumping stations for individual water supply with a built-in or remote ejector to increase the suction depth are rarely used in everyday life due to their very low efficiency of about 15%. The purchase of such devices is advisable in cases where the level of the water surface is high probability may temporarily fall below the maximum permissible level of 9 m due to various circumstances - large volumes of water intake, drought, frequent siltation of the source with a decrease in water level.
Operating principle of the ejector
Ejector pumping station Aurora, description
Reading time: 6 minutes.
Ejector pumps supply water to premises where there is no centralized water supply nearby. Such units can lift water from great depths - up to 50 meters.
Let's look at what ejector pumps exist, what advantages they have over other types of pumping systems, and how they work. We will also take into account the most important points in their operation and installation.
Pumps of this type are divided into models with a built-in ejector and a remote one. Let's look at each in more detail.
To extract water, such pumps must be lowered deep into a well or borehole. A pump with a remote ejector has two pipes. According to one of them, liquid under a certain pressure is supplied to the ejector. This leads to the development of a kind of suction jet.
A pump with an external ejector is significantly inferior in its characteristics to models with a built-in ejector. It's all about the specifics of the design.
Thus, a pump with a remote-type ejector will be “afraid” of contaminated water and air entering the structure. Its efficiency is noticeably lower, but the pump’s remote ejector also has its own significant advantage - it can be located inside a living room.
An internal centrifugal ejector pump lifts water using artificially created vacuum.
Due to its design features, an ejector pump is much more expensive than conventional devices of this type, as it is capable of lifting water even from great depths up to 50 meters.
High performance, however, is somewhat compensated for by the high level of noise emitted during operation of the device.
Therefore, ejector pumps are installed exclusively in basements and utility rooms residential buildings.
Modern steam ejector – good decision for organizing a water supply system at a large enterprise and for irrigating large areas with vegetation.
A surface pump with an external ejector has the following advantages:
Of course, not every steam ejector pump can boast all of the above advantages. So, some models can work in conditions severe frost, others - no.
The steam ejector pump has a fairly simple principle of operation - a small amount of water, which is located in a special tank of the device, is used to assist in drawing in liquid. The operating principle is simple but very effective.
Although, such a system does not have serious performance. But so far no one has invented a new pumping system that can draw liquid from greater depths. That's why a water ejector pump is so popular today.
The ejector for the pump always lowers to the required depth - to draw water, and pumping system mounted on the surface - for ease of use and adjustment of the water intake system.
An ejector pump (it doesn’t matter whether it is a pump with a remote ejector or a built-in one) must be installed in compliance with all recommendations (they are in the instructions for a specific device model).
For example, after the outlet pipe it is necessary to install a check valve. It will prevent the unit from idling. The pipe drawing in water must be located at a depth of at least 1 m. The diameter of the well, in this case, should not be less than 12 cm in diameter.
If you purchased an expensive ejector for a pump, you can also modify it - install it. It will allow you to automate the operation of the system, and can also significantly extend the operational life of your unit.
A surface pump with an external ejector, as well as a pump with an internal ejector, are mounted using two additional manipulations:
If necessary, the above-described recirculation system is additionally equipped with a tincture tap. It is necessary if the water in the well is at a level significantly higher than the level for which the equipment is designed.
The water pressure on the ejector can be adjusted by increasing the pressure in the water supply system. There are even devices that have “fine” details for tuning this parameter. Usually this detail is described in detail in the documentation for the unit.
For self-assembly the unit must be prepared:
Important! All threaded connections must be additionally sealed with polymers. If you have PVC pipes, then special crimping tubes for PVC will act as collet fittings.
Once the assembly of the device is completed, it needs to be connected to the home water supply system. If you have a system with an external ejector, you will have to connect three additional pipes to it:
An ejector is a powerful and justified device. It is capable of providing any building with sufficient water pressure, and its automation protects against idle operation, overheating and voltage surges.
Such a unit will be “faithful to you” for decades. But, only subject to full compliance with all recommendations, operating rules and systematic maintenance.
Let's figure out what an ejector is. It's worth starting with what it is integral part pumping station designed for pumping water. What is its essence?
The main purpose is to help the pumping station. In such cases, when the water is at great depth, for example, at a depth of 7 meters, a conventional pump may not be able to supply water. And then, to solve the problem of pumping water even from such a depth, an ejector is installed to help the pump. Thus, the problem is easily solved. In other words, the device is used to increase the efficiency of the pumping station.
Of course, if the water is too deep, you will need to use a technique such as a powerful submersible pump.
The ejector device is very simple; it can even be assembled manually from ordinary materials. The design of the device consists of the following parts:
The operation of the device is based on Bernoulli's law. When the speed of a certain flow increases, a field with a low level of pressure is created around it. In this regard, the effect is created discharge. The liquid, passing through the nozzle, narrowed downward according to its design, gradually increases speed. After which the liquid, entering the mixer, creates low pressure in it. Thus, the pressure of the liquid that enters the mixer through the water suction chamber increases significantly.
It is also worth noting that for proper operation ejector, it must be installed on the pump so that some part of the liquid that is lifted by the pump remains inside the device, or more precisely, the nozzle, creating the necessary pressure constantly. It is thanks to this operating principle that it is possible to maintain a constant accelerated flow. Using such a device can significantly save energy.
Depending on the installation, ejectors may be different. They are usually divided into two main types: built-in and remote. The difference between these types is small, that is, they differ only in the installation location, however, this small difference may affect the operation of the pumping station . Both types have their own advantages and disadvantages.
Built-in, as you might guess from the name, is mounted directly into the pump housing, being its integral part.
The built-in ejector has its advantages:
Among the disadvantages, we can note only low efficiency at great depths exceeding 10 meters. However, the main purpose of built-in models is to use them for pumping water from shallow depths. And one more nuance in protecting embedded devices: they provide powerful and uninterrupted water pressure. Therefore, they are often used for irrigation and other household needs.
Another minor drawback could be high level pump noise, amplified by the noise of the water flow. It is customary to install such pumps outside a residential building.
The remote, or external, device is mounted on a pumping station at a depth of at least 20 meters. And according to some experts, it is absolutely necessary to install the device at a distance of half a meter from the pump. That is, it can be placed directly in a well or brought to a water source. Thus, noise from work will not be a problem for residents. However, there are some nuances here too. For example, to connect a pump to a source, a pipe is needed so that water can return to the device. Pipe length should match the well depth. In addition to the recirculation pipe, you also need a tank from which water will be drawn.
Steam ejectors are designed to pump gas out of confined spaces and to maintain air in a rarefied state.
Steam jet devices, unlike steam devices, use the energy of a steam jet. The operating principle is based on the fact that the steam flow coming out of the nozzle carries with it at high speed a flow passing through an annular channel around the nozzle. Similar station used for pumping water from ships.
Air or gas ejector is used in gas industry. During operation of the device, the low-pressure gas environment is compressed; compression is achieved through high-pressure gas vapors.
The operation of vacuum ejectors is based on the Venturi effect. They are multi- and single-stage. Compressed air enters the device and passes through the nozzle, and this leads to an increase in dynamic pressure and a decrease in static pressure, that is, a vacuum is created. Thus, compressed air, entering the ejector, mixes with the pumped-out air and exits through the muffler.
In multi-stage ejectors, unlike the first type, the vacuum is created not in one, but in several nozzles, which are located in the same row. Thus, the compressed air passes through the nozzles and exits the muffler. Advantage of the second type is that when using the same volume of air, greater productivity is provided than in single-stage ones.
Both of these devices are jet devices, that is, for suctioning liquid and gaseous substances.
An ejector is a device in which working environment kinetic energy is transferred at high speed to the non-working, that is, passive environment, through their displacement.
Injector - device, in which gases and liquids are compressed.
The main difference between these devices is the method of transmitting energy to the passive medium. For example, in an injector the supply occurs due to pressure, and in an ejector the supply occurs due to the creation of a self-priming effect.
