Own a well at the site - a dream of many summer residents. But the well itself is only a source of water. A well pump is used to quickly and efficiently deliver it to the surface. For millenniums that have passed since the invention of the first pump, a large number of different types of these hydraulic machines have appeared. They differ in the design and principle of operation, the type of placement and type of pumped liquid, the source of energy and the field of application. In our case, the type of fluid is defined by a given application. Otherwise, well pumps can differ significantly from each other. To select the type you need, you need to familiarize yourself with their classification.
How to choose a pump for a well
Types of placement of
pumps Depending on whether the pump is submerged( fully or partially) or not, three types of pumps are allocated:
- surface;
- submersible;
- semisubmersible.
Surface pumps , as their name suggests, are located on the surface, above the level of the pumped liquid.
Sample surface pump
The design of such pumps provides for the presence of a suction hose, which is immersed at one end in the source of the liquid. Due to the fact that the pump is not immersed in water, but is on the surface, it is convenient to maintain, carry out preventive and repair work. Another advantage of this kind of pumps is that their placement can be carried out both near the well's well and at some distance from it. The drawbacks include the fact that surface pumps are very sensitive to the purity of the pumped liquid. If there are viscous and abrasive impurities in it, the pump may become clogged and fail. In addition, the depth of water rise they rarely exceeds 7-9 meters. If it is required to pump water from a deeper well, external ejectors will need to be additionally installed. In this case, the maximum depth can reach 40-50 meters.
submersible pumps operate in a fully submerged state.
Sample submersible pump
They are often installed on the bottom of a tank with a pumped liquid, but well pumps are usually mounted at a relatively shallow depth to avoid sand and mule from the bottom of the well. At the same time, the float switch must be included in the pump device, which protects the pump from "dry running" - work without pumping water. Cooling of the engine of such a pump occurs directly with the pumped liquid, so "dry running" quickly leads to its overheating and breakage. This can save an additional cooling jacket, but it complicates the design and increases the cost of the pump. The most important advantage of such pumps is that they can supply water from a depth of more than 80 meters. The suction filter protects the pump from large debris, and a completely submerged condition provides a high level of noise insulation. The disadvantage is the complexity of maintenance - for this, the pump needs to be lifted to the surface. In addition, the sealed housing is difficult to parse.
Semi-submerged pumps are mounted on a special float, so that only the pump part is immersed in the liquid, and the air-cooled engine is on the surface.
Semi submersible pump sample
The main advantage of semi submersible pumps compared to submersible pumps is that they can work at a small liquid level. They could be widely used in conditions when the use of other types of pumps is impossible or difficult - for example, when the depth of water in the well is no more than 1-1.5 meters. However, the air cooling of the engine imposes a restriction on the temperature of the ambient air - no more than 40-50 degrees Celsius. The use of such pumps is possible only in open spaces, and inside the wells they quickly overheat and fail. Therefore, semi submersible pumps should never be used as well pumps.
Pump operating principle for the
Well The forces that drive the fluid inside the pump can be of a different nature - they can be pressure forces or inertia forces. In this regard, there are two main types of pumps:
- three-dimensional;
- dynamic.
The principle of operation of volumetric pumps is based on filling the working chamber with a liquid and then displacing it.
How the
works The mechanics of this process can be different. One of the most common methods is the use of reciprocating motion with a high frequency: a vibrator makes thousands of vibrations per minute. In the first phase of the movement, a vacuum is created in the working chamber, due to which a portion of liquid enters it. In the second phase, the vibrator moves in the opposite direction, thereby creating an increased pressure, a blocking valve for fluid entry and pushing the contents of the working chamber through the outlet valve. Such pumps are also called "vibratory" pumps. They react poorly to fluctuations in the voltage in the network and contamination of the pumped liquid. And the vibration transmitted to the body can lead to the appearance of waves in the liquid medium and the rise of the bottom sediment. The advantages of vibrating pumps include relative simplicity of design and reliability.
dynamic pumps are most often understood as centrifugal pumps in which the liquid head is created by the centrifugal force resulting from the action of the rotating impeller on the fluid.
Example of operation of the dynamic pump
The fluid located between the blades of the wheel, when rotated, is forced out to the periphery and further to the output channel, and in the central part a vacuum is created, which tightens a new portion of liquid from the inlet channel. Depending on the number of impellers, one-stage and multi-stage centrifugal pumps are distinguished. The latter allow you to achieve a stronger pressure of water.
Technical data of
pumps Regardless of the type of installation and the principle of operation of the pump, when selecting it, the required specifications, such as capacity and pressure, must be taken into account. And they depend on the features of operation and architecture of the entire water supply system.
The performance of the pump must match the number of consumers and the intensity of consumption. So, the water flow per person is about 200 liters per day. In this case, the included shower consumes 9 liters per minute, the tap is 6. To irrigate 1 m? The garden requires 3 to 5 liters per day. But this indicator can vary significantly depending on weather and soil type.
Providing the minimum level of pressure is a prerequisite for delivering water to the end user. This indicator is calculated in meters, taking into account that on every 10 meters of the pipeline, 1 m of head is lost. The minimum head level is equal to the vertical distance from the highest point of the system to the level at which the pump is located, plus 20% of the length of all water pipes. To ensure a good water pressure at the output to the result, it is necessary to add another 10-15 meters.
Installing the pump for the
Well The pump installation depends on the type of installation.
Surface pump can be installed in the immediate vicinity of the well or in a separate room. The latter method is preferable if the pump is to be used also in the cold season. In addition, this arrangement will reduce the noise impact of the pump on the environment and protect it from external factors. It is necessary to remember the loss of head when using a too long plumbing system. Therefore, experts do not advise placing the pump further than 12 meters from the well.
The submersible pump is mounted with the pipeline connected to it. It is suspended on a strong kapron cord at a depth of at least 1 meter from the bottom. The minimum and maximum depth of immersion can be different for different brands. If a vibrating pump is used, it is advisable not to let it come into contact with the walls of the well. Such contact will not only create fluctuations in the water and, as a consequence, cause the slurry to rise, but it will not be safe for the design of the pump itself. If it is not possible to avoid contact with the walls, a rubber ring must be put on the pump.
Understanding the types of pumps and the features of their installation, knowing how to calculate the required capacity and pressure, you can choose the pump that is ideal for your particular conditions. But in the market every year there are new models, it is simply impossible to keep track of them for the layman. Therefore, before buying it is not superfluous to talk with a consultant in the store - he will be able to suggest the most profitable solution.
