A deep aquifer is a common problem that is well known to many land owners. Conventional surface pumping equipment either cannot provide the house with water at all, or supplies it to the system too slowly and with low pressure.
This problem needs to be resolved as soon as possible. Agree, buying a new pump is a costly undertaking and not always financially justified. A solution to this situation could be an ejector for pumping station water supply
We will tell you how to choose a suitable unit and install it without the help of specialists. We will also give step-by-step instructions on making and connecting a homemade ejector. All stages of work are accompanied by visual photographs.
The deeper the water is, the more difficult it is to bring it to the surface. In practice, if the well depth is more than seven meters, it has difficulty coping with its tasks.
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 performance of a surface pump to an acceptable level and at significantly lower costs.
The ejector is a small but very effective device. This node has relatively simple design, you can even make it yourself from scrap materials. The operating principle is based on giving the water flow additional acceleration, which will increase the amount of water coming from the source per unit of time.
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If desired, you can equip your house with autonomous water supply almost everywhere. The main problem is the depth of groundwater. If the water surface in the prepared well is at a level of 5-7 meters, then there are no special problems; you can use almost any type of pump that is suitable in terms of performance and power consumption. The situation is different with wells, where the water starts much deeper. In this case, an ejector for a pumping station will be able to cope with the task.
Natural limitations for operation are created by atmospheric pressure, water column pressure and the strength of the elements of the pumping station itself. To lift water from great depths, it is necessary to use a submersible pump or significantly increase the weight and dimensions of the equipment, which makes it simply incapacitated and consumes a huge amount of energy. To avoid such problems, it is necessary to use additional means to facilitate the rise of water, to push it towards the surface, which is why an ejector is needed.
Operating principle
The ejector is structurally a very simple device. The following main components can be distinguished in its composition:
- nozzle;
- suction chamber;
- mixer;
- diffuser.
The nozzle is a pipe, the end of which has a narrowing. The liquid flowing from the nozzle instantly accelerates, escaping from it at enormous speed. According to Bernoulli's law, fluid flow at high speeds exerts less pressure on environment. A stream of water from the nozzle enters the mixer, where it creates a significant vacuum along its boundaries.
Under the influence of this vacuum, water begins to flow into the mixer from the suction chamber. Next, the combined fluid flow through the diffuser flows further through the pipes.
In fact, in the ejector there is a transfer of kinetic energy from a medium with a higher speed to a medium with a lower speed. How can this be used in combination with a pump?
The ejector is included in the pipeline running from the well to the pump. Part of the water that rises to the surface returns back to the well to the ejector, forming a recirculation line. Escaping from the nozzle at tremendous speed, it carries with it a new portion of water from the well, providing additional vacuum in the pipeline. As a result, the pump spends less energy to lift liquid from great depths.
By using a valve installed on the recirculation line, you can regulate the amount of water flowing back into the water intake system, thereby adjusting the efficiency of the entire system.
Excess liquid not involved in the recirculation operation is supplied from the pump to the consumer, determining the productivity of the entire station. As a result, you can get by with a smaller engine and a less massive pumping part, which will last longer and consume less energy.
The ejector also makes it easier to start the system; a relatively small volume of water can create sufficient vacuum in the pipeline and initiate the initial intake of water so that the pump does not run idle for a long time.
Design and types of stations
Pumping stations can be equipped with an ejector in two ways. In the first, it is structurally part of the pump and is internal. In the second case, it is implemented as a separate external node. The choice of layout depends on the requirements for the pumping station.
Built-in ejector
In this case, the intake of water for recirculation, as well as the creation of pressure in the ejector, is created in the pump itself. This arrangement makes it possible to reduce the size of the installation.
A pump with an internal ejector is practically not susceptible to the presence of suspended matter in the form of sand and silt. There is no need to necessarily filter the incoming water.
The station is used to collect water from a depth of up to 8 meters. It creates sufficient pressure to supply a large farm, where water is mainly used for irrigation.
The disadvantage of the internal ejector is increased level noise during operation. It is best to install it outside a residential building, preferably in a separate utility room.
The electric motor is obviously selected to be more powerful so that it can also provide the recirculation system. However, this comparison is only relevant in a situation with a well depth of up to 10 meters. At greater depths, pumps with an ejector simply have no alternative, except perhaps the submersible type, which requires a well with a large diameter.
Remote ejector
With a remote ejector device, an additional tank is installed separately from the pump, into which water flows. It creates the necessary pressure for operation and additional vacuum to lighten the load of the pump. The ejector itself is connected in the submersible part of the pipeline. For it to work, it is necessary to lay two pipes into the well, which imposes some restrictions on the minimum permissible diameter.
This constructive solution reduces the efficiency of the system to 30-35%, but allows water to be extracted from deep wells up to 50 meters, and also significantly reduces the noise of an operating pumping station.
It can be located directly in the house, for example in basement. The distance from the well can be up to 20-40 meters without reducing efficiency. Such characteristics determine the popularity of pumps with an external ejector. All equipment is located in one prepared place, which increases the service life, makes it easier to carry out preventive maintenance and set up the system.
Connection
In the case of an internal ejector, if it is included in the design of the pump itself, installation of the system is not much different from the installation of a non-ejector pump. It is enough to simply connect the pipeline from the well to the suction inlet of the pump and arrange a pressure line with associated equipment in the form of a hydraulic accumulator and automation that will control the operation of the system.
For pumps with an internal ejector, in which it is fixed separately, as well as for systems with an external ejector, two additional stages are added:
- An additional pipe is laid for recirculation from the pressure line of the pumping station to the ejector inlet. The main pipe from it is connected to the pump suction.
- A pipe with a check valve and a coarse filter is connected to the ejector suction for drawing water from the well.
If necessary, a valve is installed in the recirculation line for adjustment. This is especially beneficial if the water level in the well is much higher than the pumping station is designed for. You can reduce the pressure into the ejector and thereby increase the pressure in the water supply system. Some models have a built-in valve for such a setting. Its placement and adjustment method are indicated in the equipment instructions.
Ejector - what is it? This question often occurs among owners country houses and dachas in the process of arrangement autonomous system water supply The source of water entering such a system, as a rule, is a pre-drilled well or well, the liquid from which must not only be raised to the surface, but also transported through a pipeline. To solve such problems, a whole technical complex is used, consisting of a pump, a set of sensors, filters and a water ejector, installed if liquid from the source needs to be pumped out from a depth of more than ten meters.
In what cases is an ejector needed?
Before dealing with the question of what an ejector is, you should find out why a pumping station equipped with it is needed. Essentially, an ejector (or ejector pump) is a device in which the energy of motion of one medium moving at high speed is transferred to another medium. Thus, the operating principle of an ejector pumping station is based on Bernoulli’s law: if a reduced pressure of one medium is created in a narrowing section of the pipeline, this will cause suction into the formed flow of another medium and its transfer from the suction point.
Everyone knows well: the greater the depth of the source, the harder it is to raise water from it to the surface. As a rule, if the depth of the source is more than seven meters, then a conventional surface pump has difficulty performing its functions. Of course, to solve this problem, you can use a more productive submersible pump, but it is better to go the other way and purchase an ejector for a surface-type pumping station, significantly improving the characteristics of the equipment used.
Due to the use of a pumping station with an ejector, the liquid pressure in the main pipeline increases, while the energy of fast flow is used liquid medium, flowing along its separate branch. Ejectors, as a rule, work in conjunction with jet-type pumps - water-jet, liquid-mercury, steam-mercury and steam-oil.
An ejector for a pumping station is especially relevant if it is necessary to increase the power of an already installed or planned installation of a station with a surface pump. In such cases, the ejector installation allows you to increase the depth of water intake from the reservoir to 20–40 meters.
Overview and operation of a pumping station with an external ejector
Types of ejector devices
According to their design and operating principle, ejector pumps can belong to one of the following categories.
Steam
With the help of such ejector devices, gaseous media are pumped out of confined spaces and a rarefied state of air is maintained. Devices operating on this principle have a wide range of applications.
Steam jet
In such devices, the energy of a steam jet is used to suck gaseous or liquid media from a confined space. The operating principle of this type of ejector is that steam escaping from the nozzle of the installation at high speed carries with it the transported medium exiting through an annular channel located around the nozzle. Ejector pumping stations of this type are used primarily for rapid pumping of water from the premises of ships for various purposes.
Gas
Stations with an ejector of this type, the operating principle of which is based on the fact that the compression of a gas medium, initially under low pressure, occurs due to high-pressure gases, are used in the gas industry. The described process takes place in the mixing chamber, from where the flow of the pumped medium is directed to the diffuser, where it is inhibited, and hence the pressure increases.
Design features and principle of operation
The design elements of the remote ejector for the pump are:
- a chamber into which the pumped medium is sucked;
- mixing unit;
- diffuser;
- nozzle, cross section which narrows.
How does any ejector work? As mentioned above, such a device operates according to the Bernoulli principle: if the speed of the flow of a liquid or gaseous medium increases, then an area characterized by low pressure is formed around it, which contributes to the rarefaction effect.
So, the operating principle of a pumping station equipped with an ejector device is as follows:
- The liquid medium pumped by the ejector unit enters the latter through a nozzle, the cross-section of which is smaller than the diameter of the inlet line.
- Passing into the mixer chamber through a nozzle with a decreasing diameter, the flow of the liquid medium acquires a noticeable acceleration, which contributes to the formation of an area with reduced pressure in such a chamber.
- Due to the occurrence of a vacuum effect in the ejector mixer, a liquid medium under higher pressure is sucked into the chamber.
If you decide to equip a pumping station with a device such as an ejector, keep in mind that the pumped liquid medium does not enter it from a well or well, but from the pump. The ejector itself is positioned in such a way that part of the liquid that was pumped out of the well or well by means of a pump is returned to the mixer chamber through a tapering nozzle. The kinetic energy of the liquid flow entering the ejector mixer chamber through its nozzle is transferred to the mass of the liquid medium sucked by the pump from the well or well, thereby ensuring constant acceleration of its movement along the inlet line. Part of the liquid flow, which is pumped out by a pumping station with an ejector, enters the recirculation pipe, and the rest goes into the water supply system served by such a station.
Once you understand how a pumping station equipped with an ejector works, you will understand that it requires less energy to raise water to the surface and transport it through a pipeline. Thus, not only does the efficiency of use increase pumping equipment, but also increases the depth from which the liquid medium can be pumped out. In addition, when using an ejector that sucks up liquid on its own, the pump is protected from running dry.
The design of a pumping station with an ejector includes a tap installed on the recirculation pipe. Using such a valve, which regulates the flow of liquid flowing to the ejector nozzle, you can control the operation of this device.
Types of ejectors at installation site
When purchasing an ejector to equip a pumping station, keep in mind that such a device can be built-in or external. The design and principle of operation of these two types of ejectors are practically no different; the differences are only in the location of their installation. Built-in ejectors can be placed inside the pump housing or mounted in close proximity to it. The built-in ejection pump has a number of advantages, which include:
- minimum space required for installation;
- good protection of the ejector from contamination;
- there is no need to install additional filters that protect the ejector from insoluble inclusions contained in the pumped liquid.
Meanwhile, it should be borne in mind that built-in ejectors demonstrate high efficiency if they are used to pump water from sources of shallow depth - up to 10 meters. Another significant disadvantage of pumping stations with built-in ejectors is that they produce quite a lot of noise during their operation, so it is recommended to locate them in a separate room or in a caisson of a water-bearing well. It should also be borne in mind that the design of an ejector of this type involves the use of a more powerful electric motor, which drives the pumping unit itself.
A remote (or external) ejector, as its name suggests, is installed at a certain distance from the pump, and it can be quite large and reach up to fifty meters. Remote-type ejectors, as a rule, are placed directly in the well and connected to the system via a recirculation pipe. A pumping station with a remote ejector also requires the use of a separate storage tank. This tank is necessary to ensure that water is always available for recirculation. The presence of such a tank, in addition, makes it possible to reduce the load on the pump with a remote ejector and reduce the amount of energy required for its operation.
The use of remote-type ejectors, the efficiency of which is slightly lower than that of built-in devices, makes it possible to pump out a liquid medium from wells of considerable depth. In addition, if you make a pumping station with an external ejector, then it can not be placed in the immediate vicinity of the well, but can be mounted at a distance from the water intake source, which can be from 20 to 40 meters. It is important that the location of pumping equipment at such a significant distance from the well will not affect the efficiency of its operation.
Manufacturing an ejector and its connection to pumping equipment
Having understood what an ejector is and having studied the principle of its operation, you will understand that you can make this simple device with your own hands. Why make an ejector with your own hands if you can purchase one without any problems? It's all about saving. Finding drawings from which you can make such a device yourself does not present any particular problems, and to make it you will not need expensive consumables and complex equipment.
How to make an ejector and connect it to the pump? For this purpose you need to prepare the following components:
- female tee;
- union;
- couplings, elbows and other fitting elements.
The ejector is manufactured according to the following algorithm.
- A fitting is screwed into the lower part of the tee, and this is done so that the narrow branch pipe of the latter is inside the tee, but does not protrude from it. reverse side. The distance from the end of the narrow branch pipe of the fitting to the upper end of the tee should be about two to three millimeters. If the fitting is too long, then the end of its narrow pipe is ground off; if it is short, then it is extended using a polymer tube.
- An adapter with an external thread is screwed into the upper part of the tee, which will connect to the suction line of the pump.
- A bend in the form of an angle is screwed into the lower part of the tee with the fitting already installed, which will connect to the recirculation pipe of the ejector.
- A bend in the form of an angle is also screwed into the side branch pipe of the tee, to which a pipe supplying water from the well is connected using a collet clamp.
All threaded connections made during the manufacture of a homemade ejector must be sealed, which is ensured by the use of FUM tape. On the pipe through which water will be drawn from the source, a check valve and a mesh filter should be placed, which will protect the ejector from clogging. For the pipes with which the ejector will be connected to the pump and storage tank, which ensures water recirculation in the system, you can choose products made from both metal-plastic and polyethylene. In the second option, installation does not require collet clamps, but special crimping elements.
An ejector is a jet apparatus in which the injection process is carried out, which consists of transferring the kinetic energy of one flow to another flow by direct contact (mixing).
Model:"EZh-2".
Price polyamide: 15,000.00 rub.
Price stainless steel: RUB 25,000.00
Water performance: 2 m 3 /hour.
Air performance: 0.4-0.8 m 3 / hour.
Connecting dimensions of water inlet and outlet: 1".
Connecting dimensions of the gas fitting: 1/2".
How does an ejector work?
The working flow (water) is supplied under pressure into a water-jet ejector to a convergent nozzle. In the nozzle, the water pressure decreases and the speed increases. The jet flowing from the nozzle creates a vacuum in the suction chamber and carries with it the injected medium (gas). To avoid a sharp drop in pressure and speed from the suction chamber to the mixing chamber, a confuser is provided. After passing through the confuser, the flows of two media enter the mixing chamber.
The last element of the ejector is the diffuser - it is designed to increase the pressure of the mixed flow and reduce its speed. At the outlet of the diffuser we have a flow of two mixed media.
