Ejector for pumping station: circuit, homemade device + connection

Deep occurrence of the aquifer is a common problem well known to many landowners. Ordinary surface pumping equipment either does not provide the house with water at all, or supplies it to the system too slowly and with low pressure.

This problem requires an early resolution. Agree, the purchase of a new pump is a costly and not always financially justified event. The resolution of this situation can be an ejector for a pump station of water supply.

We will show you how to choose the appropriate unit and install it without the help of specialists. And also we will give step-by-step instructions on the manufacture and connection of a self-made ejector. All stages of work are accompanied by visual photographs.

The principle of the ejector

The deeper the water is, the more difficult it is to lift it to the surface. In practice, if the well depth is more than seven meters, surface pump copes with its tasks with difficulty.

Of course, for very deep wells it is more appropriate to purchase a high-performance submersible pump. But with the help of an ejector, it is possible to improve the characteristics of a surface pump to an acceptable level and at a much lower cost.

The ejector is a small device, but very effective. This unit has a relatively simple design, it can even be made independently from scrap materials. The principle of operation is based on giving additional flow to the water flow, which will allow increasing the amount of water coming from the source per unit of time.

This solution is especially convenient for those who are going to install or have already installed pump station with surface pump. The ejector will allow to increase the depth of the water intake to 20-40 meters.

It should also be noted that the acquisition of more powerful pumping equipment will lead to a marked increase in power consumption. In this sense, the ejector will bring significant benefits.

The ejector for a surface pump consists of the following elements:

• suction chamber;
• mixing unit;
• diffuser;
• narrowed nozzle.

The operation of the device is based on the Bernoulli principle. It states that if the speed of the flow increases, a low pressure area is created around it. Thus, a dilution effect is achieved. Water enters through a nozzle whose diameter is smaller than the dimensions of the rest of the structure.

A slight narrowing gives the flow of water a noticeable acceleration. Water enters the mixer chamber, creating an area with reduced pressure inside it. Under the influence of this process, a stream of water under a higher pressure enters the mixer through the suction chamber.

The water in the ejector does not come from wells, and from the pump. Those. The ejector must be installed in such a way that part of the water raised by the pump returns to the ejector through a nozzle. The kinetic energy of this accelerated stream will be continuously transferred to the mass of water that is sucked from the source.

This will ensure a constant acceleration of the flow. Pumping equipment will need less energy to transport water to the surface. As a result, its efficiency will increase, as will the depth from which water can be taken.

Some of the water produced in this way is recycled to the ejector again, and the rest goes to the house water system. The presence of the ejector has another “plus”. It sucks water independently, which additionally insures the pump from idling, i.e. from the “dry run” situation that is dangerous for all surface pumps.

To regulate the work of the ejector, use an ordinary faucet. It is installed on the recirculation pipe, through which water from the pump is directed to the ejector nozzle. Using a tap, the amount of water entering the ejector can be reduced or increased, thereby reducing or increasing the speed of the reverse flow.

Choice: built-in or external?

Depending on the place of installation, remote and built-in ejectors are distinguished. There is no big difference in the design features of these devices, but the location of the ejector still affects in some way the installation of the pumping station and its operation.

So, built-in ejectors are usually placed inside the pump casing or in close proximity to it. As a result, the ejector takes up a minimum of space, and it will not have to be installed separately; it is enough to simply install the pumping station or the pump itself.

In addition, the ejector located in the housing is reliably protected from contamination. Vacuum and reverse water intake is performed directly in the pump casing. No need to install additional filters to protect the ejector from clogging with particles of silt or sand.

However, it should be remembered that such a model demonstrates maximum efficiency at shallow depths, up to 10 meters. Pumps with built-in ejector designed for such relatively shallow sources, their advantage is that they provide excellent pressure of incoming water.

As a result, these characteristics are enough to use water not only for domestic needs, but also for irrigation or other business operations. Another problem is the increased noise level, since the sound effect of water passing through the ejector is added to the vibration of the running pump.

If you decide to install a pump with a built-in ejector, you will have to take care of sound insulation especially carefully. Pumps or pumping stations with a built-in ejector are recommended to be installed outdoors, for example, in a separate building or in a caisson of a well.

The electric motor for a pump with an ejector should be more powerful than for a similar non-ejector model.

Remote or external ejector set at some distance from the pump, and this distance can be quite significant: 20–40 meters, some experts even consider the 50 meter indicator acceptable. Thus, the remote ejector can be placed directly at the source of water, for example, in a well.

Of course, the noise from the work of the ejector installed deep underground, will not disturb the residents of the house. However, this type of device should be connected to the system using a recirculation pipe through which water will return to the ejector.

The greater the installation depth of the device, the longer the pipe will have to be lowered into the well or well.

The presence of another pipe in the well is better to provide at the design stage of the device. Connecting a remote ejector also provides for the installation of a separate storage tank, from which water will be taken for recycling.

This tank allows you to reduce the load on the surface pump, saving some energy. It should be noted that the efficiency of the external ejector is somewhat lower than that of the built-in pump. models, however, the ability to significantly increase the depth of the fence leads to come to terms with this a disadvantage.

When using an external ejector there is no need to place pump station directly near the water source. It can be installed in the basement of a residential building. The distance to the source can vary within 20-40 meters, this will not affect the performance of pumping equipment.

Features of mounting the device

As already mentioned, the installation of an ejector built into the pump does not cause any special problems, since the device is already in the instrument case. The surface pump is simply connected to the water supply hose on the one hand, and also to the water supply system on the other hand.

If it is used as part of a pumping station, then the pump is connected to hydroaccumulator by means of a special fitting for five outlets. In addition, the pump will need to be connected to the contacts of the pressure relay to ensure its automatic on and off.

Before turning on the surface pump, it must be filled with water through the filling hole provided for this purpose. It is impossible to turn on such equipment without water, it can burn out. If the pump is installed correctly, the ejector will work without interruption.

But the installation of a remote ejector is made according to a more complex scheme. To begin with, it will be necessary to install a pipe that will provide a reverse flow of water from the reservoir to the ejector. On the intake section of the ejector set check valve. Behind him should put a strainer that will protect the device from clogging.

On top of the recirculation pipe, you must install an adjustment valve to regulate the amount of water that is directed to the ejector. This site is not mandatory, but can significantly improve the situation with the pressure of water in the house.

The less water will be returned to the ejector, the more it will remain for the plumbing system at home.

This way you can influence water pressure in the water. With its deficiency, tighten the adjusting valve on the return line a little.

If the pressure is too high and creates an unnecessary load on the plumbing system, it makes sense send more water to the ejector to increase the efficiency of the pump equipment.

Some industrial models of ejectors are already equipped with such an adjustment system. The instructions attached to the device usually describe in detail how to configure the operation of the ejector.

Using a homemade external version

The built-in ejector is usually purchased at the same time as the pump, but the external model is often made by hand.

It will be useful to consider the process of creation and the order of connection of such a device. In order to make an ejector, you will need details such as a tee with internal threaded connections, a fitting, fittings, bends, couplings, etc.

Autographic assembly of the ejector

Assemble the device as follows:

1. Connect the lower part of the tee with a fitting so that the outlet nozzle is at the top, and the fitting with a smaller diameter is inside the ejector.
2. Then you need to modify the design, cutting down the narrow part of the fitting, if it protrudes from the tee.
3. If the fitting is too short, it is expanded using a plastic tube.
4. On the upper side of the tee screw adapter with external thread.
5. A PVC water pipe is connected to the other end of the adapter using a fitting.
6. Now to the bottom side of the tee, in which the narrow fitting is already inserted, it is necessary to attach the elbow in the form of a corner.
7. A pipe is connected to this outlet through which the return flow of water to the ejector will flow.
8. To the side pipe tee attach another corner.
9. A pipe is attached to this corner with a collet clamp, and water from a well, a well, etc. will be sucked through it.

The distance between the edge of the tee and choke should be about 2-3 mm. This will create a dilution area with the required characteristics. A crimp nut is used to secure the recycle pipe.

It turns out that two elements are simultaneously attached to the internal thread of the lower branch pipe of the tee. One of them (fitting) is inside the tee, and the second (corner) - outside. To both fit on the same threaded connection, you should cut off part of the thread fitting.

Of course, all threaded connections must be sealed and sealed. Most often for this use FUM tape. Sometimes to connect the ejector to pumping station do not use metal pipes, and designs of polyethylene.

For their installation, you should use special crimping elements, and collet clamps, which are good for metal, in this situation will not work.

Pipe connection procedure

It is necessary to think in advance about which pipes will be connected to the external ejector. Polyethylene constructions bend well when heated, which allows you to do without corners when connecting an ejector. The pipe is simply bent in a suitable place and at the right angle, and then attached to the ejector.

So, the device has three outputs, each of which should be connected to the appropriate pipe. At first, a pipe is usually installed through which water will be taken from the source. She joins the side exit of the ejector.

At the end of this pipe, a check valve is installed, as well as a strainer. This tube should be long enough to sink deep into the water. But you should not take water at the very bottom of the source, as this can lead to clogging of the ejector, despite the presence of a filter.

Then you can attach the pipe to the lower end of the ejector, which is installed narrower fitting. This is the highway through which water is recycled. The second end of this pipe should be connected to a tank from which water will be taken to create a reverse flow.

The third pipe is a regular water main. At one end it is mounted on the upper nozzle of the ejector, and the other is attached to the surface pump. It should be remembered that the diameter of the pipe through which water is taken from the source must exceed the size of the pipe through which water is supplied to the ejector.

If an inch pipe is used in the feed, it is recommended to take a quarter inch larger pipe for suction. After all connections are made, the ejector is immersed in water.

Before the first start-up of the system it is necessary to fill it with water. The pump is poured through a special hole. Pipes leading to the ejector must also be filled with water.

Initial launch and further operation

The initial start-up of the pumping station is recommended as follows:

1. Pour water into the pump through a special hole.
2. Shut off the tap through which water flows from the pumping station to the water distribution system.
3. Turn on the pump for about 10-20 seconds and turn it off immediately.
4. Open the valve and release some air from the system.
5. Repeat the cycle of short-term switching on / off of the pump in combination with bleeding air until the pipes are filled with water.
6. Turn on the pump again.
7. Wait until the accumulator is filled and the pump is automatically shut off.
8. Open any water tap.
9. Wait for the water to flow out of the accumulator and the pump will turn on automatically.

If the water did not go when the system was started up with an ejector, it is possible that air somehow seeps into the pipes, or the initial water fill was not performed correctly. It makes sense to check the presence and condition of the check valve. If not, the water will simply pour into the well, and the pipes will remain empty.

These points should be taken into account when using a pumping station with an ejector that starts after a long storage period. It is best to check the check valve, the integrity of the pipes and the tightness of the connections immediately.

If everything is in order, and water does not flow, you need to check the voltage supplied to the pumping station. If it is too low, the pump simply cannot operate at full capacity. It should establish a normal power supply equipment, and the problem will disappear.

If the ejector is needed to improve the water pressure in the system, and not to increase the depth of water intake, you can use the self-made ejector model described above.

But it does not need to be immersed in water, it can be placed in a convenient place near the surface pump. In this case, the ejector will work about the same as the built-in industrial production model.

Conclusions and useful video on the topic

This video describes in detail the depth of suction of the surface pump and options for solving the problem using an ejector:

The principle of operation of the ejector is clearly demonstrated here:

Ejector - simple, but very useful device. This is a convenient and practical way to improve the performance of pumping equipment in a private home. But the installation of the ejector, especially the remote model, must be carried out correctly, only this way it is possible to provide a noticeable increase in the water pressure.

Anyone interested in the choice and connection of the ejector, we offer to join the discussions and leave comments on the article. The comment form is below.