Submersible pumps are perfect when using ring wells. The pumps are installed in special protective pipes. The pumps have a cooling jacket installed. The role of monoblock submersible pumps is to suck water from the bottom up, some models additionally have a shredder function, which we present in the video: https://www.youtube.com/watch?v=25uq0YBIw78&t=28s
What is the casing pipe used for?
By choosing the right one submersible pump, matching the diameter of the well, we should not limit ourselves to this one criterion. It is equally important to pay attention to tank width, because too large a width may have a negative impact on the life of the pump motor. We will show this with an example IBO 3.5SDM 3-15 pumps with a diameter of 90 mm and:
A - deep well with an internal diameter of 100 mm,
B - circular well with a diameter of 1 m.
In the first case, where the difference between the pump and the well wall is 5 mm, the amount of water surrounding the pump is also small, which results in efficient water exchange and is constantly replenished from the deposit located around the well. Efficient water flow helps cool the engine. However, if the distance between the pump and the well wall is almost 0.5 m, then water is sucked in at the height of the suction port and the engine is not cooled. The engine heats up during operation, increasing the water temperature, which shortens its service life.
General rule for pump selection
The general rule for selecting a pump for the well diameter is that the difference between the pump diameter and the internal diameter of the well should be not less than 4 mm and not more than 100 mm. It is worth taking this into account when purchasing a pump, because submersible pumps with a diameter of 50 mm to 160 mm are most often available on the market. How a professional pump with a grinder works IBO KRAKEN 1800 for dirty sewage water we present in the video: https://www.youtube.com/watch?v=srPLsaIKsqM&t=27s
Other hazards in pump operation
The presence of sand in the well is one of the most common reasons for pump failure. Therefore, we recommend checking out the offer of the Polish manufacturer IBO deep well pumps, pumps from the 2.5STM, 3STM, 3ti, 3SDM, 3.5SDM, 4SDM IBO series have a structure based on the so-called floating rotors. This design means that the individual stages of the pump, including the impellers, are located on the pump shaft. Such mounting allows for maintaining longitudinal play, which allows the entire hydraulic part located inside the tube to be moved up and down by a few centimeters. Even if sand gets inside, thanks to the remaining clearance, the structure will not be damaged. The recommended pump models were the first on the Polish and European market to be nicknamed pumps „ANTI-SAND”.
Another model that uses this solution are pumps made in Italy IBO ITALY from the FP4 series. Additionally, they are characterized by the "DRY RUN PRO" solution, which protects the pump against operation in the so-called dry circulation, i.e. without water - e.g. when the water table is lowered due to drought.
