Almost anywhere 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 the usual submersible pump for lifting water from great depths. Certain restrictions on the operation of a conventional pumping station will be created by water pressure, atmospheric pressure and the strength of the pump’s structural parts. 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.

Operating principle

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:

• A pipe with a narrow end called a nozzle. The water flowing through the nozzle acquires great acceleration and leaves this device at high speed. What is this for? The thing is that the flow of water at high speed does not exert such great pressure on the surrounding planes.
• Mixing device. Water from the nozzle enters this device. Here there is a significant discharge of the entire volume of liquid.
• Suction container. Under the influence of vacuum in the mixer, water from the well begins to flow into the suction chamber. After this, the mixed flow of liquid enters the next element - the diffuser.
• Diffuser. From this part of the structure, the liquid moves further through the pipeline.

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 the 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 to lift 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 the productivity of pumping equipment is judged.

Advantages of ejector type pumps:

• there is no need to choose a unit with a powerful engine;
• the pumping part will not be so massive;
• this will ensure lower energy consumption and longer operation of pumping equipment;
• thanks to the ejector, it is easier to start all pumping equipment, since there is no large number water creates sufficient vacuum in the pipes.

Features and types of design

There are two types of ejector type pump:

• with external ejector location;
• with internal (built-in) ejector location.

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.

Internal ejector

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:

• the unit is not sensitive to heavy impurities in water (silt and sand);
• the water entering the equipment does not need to be filtered;
• the device is suitable for lifting water from a depth of no more than 8 m;
• Such pumping equipment provides sufficient liquid pressure for domestic needs.

Among the disadvantages it is worth noting the following:

• this pump makes a lot of noise during operation;
• To install such a unit, it is better to choose a place away from the house and build a special room.

External ejector

To perform 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:

• thanks to this design, it is possible to lift water from a significant depth (up to 50 m);
• it is possible to reduce the noise from the operation of pumping equipment;
• such a structure can be placed directly in the basement of the house;
• without reducing the efficiency of the pumping station, the ejector can be placed at a distance of 20-40 m from the well;
• thanks to the fact that everything necessary equipment located in one place, it is easier to carry out repairs and commissioning work, which contributes to a longer service life of the entire system.

Disadvantages of the external location of the ejector device:

• system performance is reduced by 30-35 percent;
• restrictions in the choice of pipeline diameter.

How to connect?

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:

1. To ensure recirculation, it is necessary to lay an additional pipeline from the inlet pipe of the ejector device to the pressure line of the pumping equipment.
2. A pipe with a check valve is connected to the inlet of the ejector, on which a coarse filter is installed for pumping liquid out of the hydraulic structure.

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 design level of the liquid for pumping equipment. Thanks to this valve, it is possible to reduce the pressure in the ejector and cause an increase 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.

To supply water from wells, centrifugal surface pumps are most often used; less often they are used to supply water from a well. Application of this type pumps have a limitation, which is the inability to lift water from a depth of more than 8 m; if the water surface in the well is below 8 m, then it will not be possible to lift water with a conventional pump. In order for the pump to lift water from a greater depth into the system, you need to include an additional device called an ejector. It is not always possible to find it on sale, and the prices are high, but making an ejector for a pumping station with your own hands from scrap materials is quite possible. It will, of course, not be as effective as an ejector industrial production, but is guaranteed to add about 5 m to the missing depth.

How does an ejector work?

The principle of operation of the ejector is based on the movement of water in the pipe, which, when entering the smoothly tapering part of the ejector, increases its speed, as a result of which a zone with reduced pressure is formed, into which water is sucked in from the outside. The remote ejector of the pumping station operates by supplying water through a recirculation pipeline; the flow, entering the tapering part, increases speed, forming a zone with reduced pressure, where to compensate low pressure, water begins to be absorbed from outside. In other words, the ejector pushes water to a height from which the pump can independently suck it up.

The efficiency of the ejector is characterized by the ejection coefficient, which shows the amount of sucked water per unit amount of recirculated water. In our case, the water ejection coefficient is 0.12, that is, with a water flow rate in the ejector of 1000 l/hour, the ejector will suck in about 120 l/hour.

Ejector design (option 1)

The simplest ejector can be assembled based on a tee and fitting - these parts will perform the function of a Venturi tube in a very simplified version. Shaped elements for the ejector can be used from different material(metal, plastic). IN in this case The ejector design is assembled from a brass tee and collet fittings for metal-plastic pipes.

The diameter of the shaped elements for the ejector design is taken depending on the performance of the pumping station and the diameter of the suction and recirculation pipeline; the diameter of the suction pipeline cannot be less than 25 mm. In our design, a tee with a diameter of 20 mm will be used with a 26 mm suction pipeline and a 12.5 mm recirculation pipeline connected to it.

1. Tee ½" mm.
2. ½" mm fitting with 12 mm outlet.
3. Adapter 20×25 mm.
4. Angle 90º (external/internal) for metal-plastic pipe½"×16 mm.
5. Angle 90º (external/internal) for metal-plastic pipe ¾"×26 mm.
6. Angle 90º (external/internal) ¾"×½".

The difficulty in this design can be the fitting; it will have to be modified a little, namely, the hexagon must be turned to a cone-shaped state.

The lower base of the resulting cone should have a diameter several millimeters smaller than the outer diameter of the fitting thread, and its thread should also be shortened so that a maximum of four turns remain. Using a die, you need to drive the thread and cut a few more turns on the resulting cone.

Now you can assemble the ejector. To do this, screw the fitting (2) with the narrow part inside the tee (1) so that the fitting extends 1–2 mm beyond the upper edge of the side outlet of the tee, and so that at least four turns remain on internal thread tee so that the outlet (6) can be screwed in. If the remaining free thread of the tee is not enough, you will need to grind off the threads of the fitting; if the length of the fitting is not enough, you can put a piece of tube on it. It is necessary to connect to the outlet (5) through which water will be suctioned. check valve so that when starting the system, water does not overflow from the suction and recirculation water pipes, otherwise the system will not start. You also need to seal everything threaded connections using any sealant.

Such an ejector will not have a high ejection coefficient due to the imperfect design of the Venturi tube, so it can be used to lift water from a depth of no more than 10 m.

Option 2

There is another option to make an ejector, this design is more efficient due to the more advanced Venturi tube, it is more complex to manufacture, but the ejection coefficient will be higher than in the previous model.

1. Tee Æ 40 mm.
2. Bend 90º 1/2" mm.
3. Squeeze 1/2" mm.
4. Squeeze 3/4" mm.
5. Lock nut 1/2" mm.
6. Lock nut 3/4" mm.
7. Stub.
8. Check valve.
9. Fitting 1/2" mm.
10. Fitting 3/4" mm.
11. Nozzle 10 mm.
12. Threaded connection 1/2" mm.

Such an ejector is made from steel shaped parts. As a nozzle (11) you can use copper tube, make longitudinal cuts in it, compress it, and solder the seams. In the plugs (7), you need to make holes of a suitable diameter and cut a thread in order to screw in the bends (3 and 4) and secure them with locknuts. The nozzle will need to be fixed in the drive using soldering.

Features of installation and operation

The operation of the ejector will be effective only on powerful pumps, at least 1 kW s high performance, and the installation depth of the ejector is no more than 20 m; installation deeper sharply reduces the efficiency of the ejector. To ensure that there are no malfunctions when operating a pump with a remote ejector, the supply pipes to the ejector must be placed strictly vertically. There must be a coarse filter in front of the pump, since such pumps are very vulnerable to the effects of abrasive particles that can damage the pump. In front of the pump, on the recirculation pipeline, it is necessary to install a tap so that you can regulate the amount of return water, thereby regulating the suction efficiency of the ejector.

Photo

A pumping station with an ejector is part of a water supply system that operates in autonomous mode. The principle of operation of the ejector is that it regulates the water pressure in the pipe. In this case, water moves from the well to the surface - to the consumer.

The problem of low water pressure can be solved by installing an ejector for a pumping station

All design elements are responsible for the energy efficiency of such a station. At the same time, water supply from a depth of 10 m or more is provided only by an ejector pump. Without this device, the station pumps water only from a well, the depth of which is a maximum of 7 m.

This article talks about both the types and design of the ejector, and how to create an ejector.

Types and typical varieties of ejector pump

• - a vacuum pumping device that pumps gas out of indoors and maintains a vacuum. Such a device is used in technical devices that provide water supply to consumers;
• steam jet - which uses the steam energy of a jet when pumping water, vapor or gas from an enclosed space. This device was used on river and sea vessels when pumping out water.

An ejection pump is considered a device that increases the water pressure in a pipe. In this case, ejection occurs - the use of the energy of a fast flow of water that flows through a special branch.

Configuring such equipment occurs as follows:

1. first, the pipe through which water flows is connected to the left chamber pipe of the mixer, which has a T-shape;
2. then, a tube through which a high-speed flow moves is connected to the chamber pipe located below. In this case, the tube and pipe must be thinner than the pipe through which the water flows;
3. further, the right pipe is used as a diffuser, in which two flows of water are mixed - liquid supply and high-speed.

After mixing both flows, a vacuum is formed in the chamber, which accelerates the movement of water in the left pipe supplying water.

The efficient operation of the station depends on all structural elements, but the transportation of water depends entirely on the ejector

Such a chamber is essentially also considered an ejector pump. It is installed either in the 1st building or separately.

As a result, such an installation expands the range and divides them into built-in and external.

At the same time, the energy efficiency of a pumping station depends on which ejector is installed on it.

If it is equipped with a remote rather than a built-in ejector pump, then its efficiency is 30%. In this case, a vacuum ejector.

At the same time, the built-in pumping station produces a lot of noise, and the external ejector operates quietly.

All advantages and disadvantages directly affect the choice.

External ejector pumping stations are installed in a well located at great depth. They are connected high power, which is installed indoors.

Internal pumping stations are connected to less powerful motors that are installed outside the house - where there is a shallow well (well).

Features and principle of operation of the installation

At factories producing wastewater disposal equipment, 2 types of pumping equipment are manufactured - with an internal and external ejector pump.

Devices with an internal ejection device pump out water from shallow (8 m or less) wells, reservoirs and wells.

A feature of such equipment is the presence of a “self-priming” function, as a result of which the water level is regulated, which is below the level of the inlet pipe. In this regard, before turning on the device, it is necessary to fill it with water.

Device diagram: 1- tee; 2 - fitting; 3 - vinyl chloride tube; 4 - adapter for metal-plastic pipe; 5 - NxMP angle; 6 - angle НхВ; 7 - NxMP angle

After the device is filled with water and turned on, impeller installations with an internal ejector pump send water to the inlet of the ejector, thereby forming the necessary jet. It moves through a thin tube and the water pressure becomes faster.

When a pipe is connected to the inlet pipe, water begins to flow into the station.

The water then enters a chamber which sucks up the liquid. At the same time, the water pressure becomes less and the liquid flows through the diffuser to the outlet, slightly increasing the flow speed.

A device that uses an external ejector for a pumping station differs from an internal ejection pump in that it is used only at a depth of 10 m or more.

It is also difficult to install external ejector pumps on these devices. The pipes that connect the pumping devices to each other are installed only in a vertical position. Otherwise, a lot of air will enter the inlet line and it will stop working normally.

The optimal option for using devices with a remote ejector is to install the device at a depth of 20 m. As the lifting height increases, its performance decreases.

As a result, remote pumping device has lower efficiency than internal.

Self-production of an ejector

In order to make an air ejector with your own hands, you need to purchase the following set of parts, consisting of fittings and mating elements:

1. tee - the basis of the air ejector being designed;
2. fitting – conductor of high water pressure in the device;
3. couplings and bends - these elements are used for self-assembly ejector apparatus.

Connection diagram of the ejector to the operating line of the pumping station

In order to assemble an ejector for a pumping station from parts with your own hands, you must perform the following steps:

• first, you should take a tee, the ends of which are used for threaded installation. In this case, the threads on its ends must be internal;
• Next, a fitting should be installed on the lower part of the tee. In this case, the fitting should be attached to the tee so that the small pipe is inside the pumping apparatus. In this case, the pipe should not appear at the end, which is located on the opposite side of the tee.

If the pipe turns out to be too long, then it must be shortened and sharpened.

In the same way, the short fitting is enlarged by using a polymer tube. The distance between the ends of the tee and the fitting should be 2-3 mm;

• then, on top of the tee - above the fitting, an adapter should be installed. Moreover, 1 end of the adapter must be made under external thread(it must be installed on the base of the pumping apparatus), and the second one is installed as a crimp elbow (fitting) under the metal-plastic pipeline through which water flows from the well;
• At the bottom of the tee with the fitting installed, a 2nd crimp bend is installed, onto which the recirculation line pipeline must be put on and secured with nuts. In this regard, before installing the device, you must first grind the lower part of the fitting to 3-4 threads;
• Upon completion of the assembly of the homemade pumping apparatus, a second angle should be screwed into the branch on the side, at the end of which it is installed for installing the water supply.

The connection using threads is made on seals made of polymers - fluoroplastic sealing material (FUM).

After completing the assembly of the homemade ejector pump, it is connected to the station itself.

If you install a homemade ejector outside the well, you will end up with a station with a built-in ejection device.

If the ejector device is installed in a shaft in which it is covered with water, you will get a station with an external ejection device.

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When installing this homemade apparatus 3 pipes should be connected to the tee at the same time:

• 1st - to the end, which is located on the side of the tee. The pipe is lowered to the bottom, and a filter with a mesh is installed at its end. A small pressure of water begins to flow through such a pipe;
• 2nd - to the end, which is located at the bottom of the tee. It is connected to the pressure line that leaves the station. As a result, the water flow rate in the ejector pump begins to increase;
• 3rd - to the end, which is located on top of the tee. It is brought to the surface and connected to a pipe that sucks in water. Through such a pipe, water will flow with even greater pressure.

As a result, the first pipe will be under water, and the second and third will be on the surface of the water liquid.

The price of an ejector for a pumping station ranges from 16-18,000 rubles. and depends on its technical characteristics.

An ejector is a device that is designed to transfer kinetic energy from one medium moving at a higher speed to another. The operation of this device is based on Bernoulli's principle. This means that the unit is capable of creating a reduced pressure in the tapering section of one medium, which, in turn, will cause suction into the flow of another medium. Thus, it is transferred and then removed from the site of absorption of the first medium.

General information about the device

The ejector is small but very efficient device, which works in tandem with a pump. If we talk about water, then, naturally, a water pump is used, but it can also work in tandem with a steam pump, a steam-oil pump, a mercury steam pump, or a liquid-mercury pump.

The use of this equipment is advisable if the aquifer lies quite deep. In such situations, it most often happens that conventional pumping equipment cannot cope with providing the house with water or supplies too little pressure. An ejector will help solve this problem.

Species

An ejector is a fairly common piece of equipment, and therefore there are several various types of this device:

• The first is steam. It is intended for the suction of gases and confined spaces, as well as for maintaining a vacuum in these spaces. The use of these units is widespread in a variety of technical industries.
• The second is steam jet. This device uses the energy of a steam jet, with which it is able to suck out liquid, steam or gas from a confined space. The steam that comes out of the nozzle at high speed carries with it the moving substance. Most often used on various vessels and ships for rapid suction of water.
• A gas ejector is a device whose operating principle is based on the fact that overpressure high-pressure gases are used to compress low-pressure gases.

Ejector for water suction

If we talk about water extraction, then an ejector for a water pump is most often used. The thing is that if afterward the water turns out to be lower than seven meters, then an ordinary water pump will cope with great difficulty. Of course, you can immediately buy a submersible pump, the performance of which is much higher, but it is expensive. But with the help of an ejector you can increase the power of an existing unit.

It is worth noting that the design of this device quite simple. Production homemade device also remains a very real challenge. But for this you will have to work hard on the drawings for the ejector. The basic operating principle of this simple apparatus is that it gives the flow of water additional acceleration, which leads to an increase in the supply of liquid per unit time. In other words, the task of the unit is to increase water pressure.

Components

Installing an ejector will greatly increase the optimal water intake level. The indicators will be approximately equal to 20 to 40 meters in depth. Another advantage of this particular device is that its operation requires much less electricity than, for example, a more efficient pump would require.

The pump ejector itself consists of the following parts:

• suction chamber;
• diffuser;
• narrowed nozzle.

Operating principle

The operating principle of the ejector is entirely based on Bernoulli's principle. This statement states that if you increase the speed of any flow, then an area of ​​​​low pressure will always form around it. Because of this, an effect such as discharge is achieved. The liquid itself will pass through the nozzle. The diameter of this part is always smaller than the dimensions of the rest of the structure.

It is important to understand here that even a slight narrowing will significantly accelerate the flow of incoming water. Next, the water will enter the mixer chamber, where it will create a reduced pressure. Due to the occurrence of this process, it will happen that liquid will enter the mixer through the suction chamber, the pressure of which will be much higher. This is the principle of the ejector, if we describe it briefly.

It is important to note here that water should not come into the device from a direct source, but from the pump itself. In other words, the unit must be mounted in such a way that some of the water that is lifted by the pump remains in the ejector itself, passing through the nozzle. This is necessary so that it is possible to supply constant kinetic energy to the mass of liquid that needs to be lifted.

Thanks to work in this way, a constant acceleration of the flow of matter will be maintained. One of the advantages is that using an ejector for the pump will save a large amount of electricity, since the station will not operate at the limit.

Pump device type

Depending on the location, there may be a built-in or remote type. There are no huge structural differences between the installation locations, however, some small differences will still make themselves felt, since the installation of the station itself will change slightly, as well as its performance. Of course, it is clear from the name that built-in ejectors are installed inside the station itself or in close proximity to it.

This type of unit is good because you do not have to allocate additional space for its installation. The installation of the ejector itself also does not have to be carried out, since it is already built-in; you only need to install the station itself. Another advantage of such a device is that it will be very well protected from various types of contamination. The disadvantage is that this type of device will create quite a lot of noise.

Comparison of models

Remote equipment will be somewhat more difficult to install and you will have to allocate a separate place for its location, but the amount of noise, for example, will be significantly reduced. But there are other disadvantages. Remote models can provide efficient work only at a depth of 10 meters. Built-in models are initially designed for sources that are not too deep, but the advantage is that they create a fairly powerful pressure, which leads to more effective use liquids.

The generated jet is quite enough not only for domestic needs, but also for operations such as watering, for example. Increased level noise from the built-in model is one of the most significant problems that you will have to take care of. Most often, it is solved by installing it together with the ejector in a separate building or in a well caisson. You will also have to worry about a more powerful electric motor for such stations.

Connection

If we talk about connecting a remote ejector, you will have to perform the following operations:

• Laying an additional pipe. This facility is necessary to ensure water circulation from the pressure line to the water intake installation.
• The second step is to connect a special pipe to the suction port of the water intake station.

But connecting the built-in unit will not differ in any way from the usual process of installing a pumping station. All necessary procedures for connecting the necessary pipes or pipes are carried out at the factory.

An ejector is a device in which kinetic energy is transferred from one medium moving at a higher speed to another.
A pump is an actuator that converts mechanical energy engine (drive) into hydraulic energy of fluid flow. The pump, driven by the engine, communicates with the tanks by two pipelines: suction (receiving) and discharge (discharge).
According to the principle of operation, marine pumps are divided into three groups: positive displacement (displacement), vane and jet. Jet pumps have no moving parts and create a pressure difference using working environment: liquid, steam or gas supplied to a pump under pressure. These pumps include ejectors and injectors.
Jet pumps connected to the object being served by a suction pipe are called ejectors. For ejectors, the working pressure is higher than the useful one, that is. Ejectors are divided into water ones - for drying, steam - for sucking air and creating a vacuum in condensers, evaporators, etc.
Jet pumps connected to the serviced object by a discharge pipe are called injectors. Injectors have the opposite pressure ratio, that is, the useful pressure is higher than the working one. Injectors include steam jet pumps for supplying feedwater to steam generators.
Figure 1 shows a water-jet drainage ejector of the VEZH type.
The ejector body 3, welded from sheet copper, has the shape of a diffuser with an angular suction pipe 7, the hole of which is closed by a cap 6 with a chain. On the left, a brass nozzle 2 is inserted into the body, having the shape of a converging nozzle with a half-nut “Storz” 1 for connection flexible hose, through which working water is supplied to the ejector. To connect the outlet hose to the ejector, use a half-nut 4, located at the outlet end of the discharge pipe 5. This connection ensures the operation of portable ejectors, which are installed on the threads of deck bushings communicating through tubes with compartments or holds that require drainage.

Rice. 1 Water-jet ejector type VEZH

The ejector works as follows: working water is usually supplied from the fire main under pressure to the nozzle. From the narrow exit section of the nozzle, water flows at high speed into the so-called mixing chamber, and the pressure decreases. Passing through the narrow section of the diffuser (“neck”), water carries along air and creates a vacuum in the mixing chamber, which ensures the flow of liquid from the suction pipe 7. Due to friction and as a result of the exchange of impulses, the sucked water is mixed, captured and moves along with the working one. The mixture enters the expanding part of the diffuser, where the kinetic energy (speed) decreases and, due to this, the static pressure increases, facilitating the injection of the liquid mixture through pipe 5 into the discharge pipeline and overboard. The ejector feed can be adjusted by screwing in or out the nozzle.
Figure 2 shows a steam jet injector used to power steam boilers.
Working steam from the boiler is supplied to pipe 1 of the injector. Valve 2 is opened by turning handle 10. Steam, passing through steam nozzle 9, acquires higher speed by reducing pressure. At the same time, it entrains air particles and creates a vacuum, which ensures that feed water enters the pump through pipe 3. The incoming water, mixing with the steam, condenses it. Reducing the volume increases the vacuum in the mixing chamber 4, ensuring continuous suction of feed water into the injector. The mixture of condensate and water flows through the diffuser 6 to the non-return valve 5, which covers the entrance to the boiler feed pipe. As a result of the transfer of part of the kinetic energy of the mixture into pressure, the valve opens and hot water enters the steam boiler.

Rice. 2 Steam jet injector

If the discharge pressure in front of valve 5 is less than the pressure in the boiler, the valve will not open. In this case, the water mixture in chamber 7 will press the pilot valve and will pour out through hole 8.
When the pressure becomes sufficient to open valve 5, the pressure in chamber 7 will decrease and the pilot valve will close under the action of a spring, preventing water from flowing out. Steam injectors have a simple design and supply hot feed water to the steam boiler, but are ineffective and uneconomical.
The absence of moving parts in the jet pump ensures pumping of liquid with various mechanical inclusions, which is used on fishing industry vessels for pumping pulp, that is, a mixture of fish and water, using airlift pumps or hydraulic elevators. Unlike centrifugal fish pumps, airlifts do not damage the fish when pumping pulp. Airlifts use compressed air as a working medium, which, when mixed with water, creates a reduced density for it.
The main disadvantage of jet pumps is their low efficiency, which is usually not higher than that of airlifts.