Without the implementation of an automatic water supply system, it is hard to imagine comfortable living in a suburban house without centralized water supply. One effective solution to this issue is the installation of a pumping station. Most suburban houses have wells on their premises, with a depth to the water table exceeding 15 meters. The process of installing a pumping station involves submerging the pump in the well shaft (water), and a pipe leading to a special storage tank (hydro accumulator) is connected to it through a pressure switch. The working scheme looks as follows: water – pump – pipeline – pressure switch – hydro accumulator – water distribution system with taps. In this article, we will explore one of the key elements of this system – the submersible pump.
Pumps
Ready-made pumping stations that can be purchased in stores often do not suit the water supply needs of a suburban house, as their basis is a conventional centrifugal pump designed to operate on the surface. Suppose we place such a station near the well and lower the intake hose. If the distance to the water table is less than 10 meters, the pump will be able to pump it out, but if the depth is greater, it will be impossible. The reason is that every ten meters of depth creates a pressure of 1 atmosphere, which opposes the vacuum created by the pump. Thus, on our planet, it is impossible to raise a column of water higher than 10 meters to the surface. In practice, however, the acceptable depth is 5-7 meters. Injector pumps partially overcome this limit, but their installation is not always practical for domestic pumping stations.
In contrast, the submersible pump for the pumping station operates on a different principle. Such models have a hermetic casing and a resin-encapsulated power cable, allowing them to operate underwater. A pipe or hose is connected to the pump casing, and with the help of special ears, the pump is secured on a cable that holds it.
The immersion depth is indicated in the specifications and usually does not exceed 2 meters.
Diversity of Solutions
Submersible pumps vary in principle of operation, characteristics, and cost. The cheapest among them are vibration pumps. Inside the casing is an electromagnet shaped like the letter "P". One part is resin-filled, while the other is movable. When voltage is applied, a magnetic field is generated that attracts the movable part with a piston, pushing the entire system. The valve system allows water to flow to the outlet, resulting in water being lifted through stamped channels in the casing. The design of the vibration pump is very simple.
The advantages of the vibration pump as part of the pumping station are:
- Low cost: the price of a vibration pump is usually 5-6 times lower than that of its centrifugal counterparts;
- Simplicity of repair and maintenance, which can be performed independently;
- Low power consumption, rarely exceeding 300 watts, allowing for savings on electricity costs.
However, vibration pumps are not always practical for the following reasons:
- Vibration during operation transmits to the well walls, which may lead to the need for cleaning;
- Vibration can negatively affect boreholes, damaging the insulation between the rings;
- If the hydro accumulator is located in the house, the noise from the operating pump can be quite noticeable;
- Regular monitoring of the condition of rubber pistons and valves is necessary;
- Dependence on power supply parameters: voltage surges or drops can negatively affect pump operation.
The next type of pumps is the screw pumps. Inside the casing is a "screw" similar to those used in meat grinders. The main disadvantage is the short lifespan of the screw material. Lastly, the most popular are centrifugal submersible pumps. They use a wheel system that pushes water upward. Metals or polymers are used in their manufacturing. A quality model can operate without being removed from the well for up to 7 years. Unfortunately, their power consumption exceeds 1 kW, and their cost is roughly equivalent to a month's salary of the average city dweller.