The presence of dissolved substances in water (lime, sulfur compounds, etc.) and suspended particulate matter leads to clogging and abrasion resistant impeller. Ability to work under such conditions is one of the main operational characteristics of submersible pumps for wells.
Clogged impeller mainly occurs when stopping the pump. The flow rate is reduced and the weighted sand precipitates filling the space in the channels of hydraulic pump and that the most dangerous in the gaps between the planes of the impeller and the diffuser clips. When the pump starts again, the accumulated sediment has the strongest influence on the abrasive impellers and may even cause them to jam. This usually leads to expensive repair (removal of the pump from the well, its disassemble, cleaning, replacement of components, assembly, installation on the back seat).
The technology of “floating” of the impeller, can significantly reduce the effects of friction on the wall of sand and flat surface of the blades of the impeller and diffuser, a high degree of reliability and long service life of the pump unit. Impellers in this embodiment is not rigidly fixed to the shaft, but have little free running along the shaft.
When starting the water pump impeller by rotating jet of water is injected between the impeller and diffuser. Creates pressure raises the rotor. In this sandy sediment flux shall be made part of which lies below the rotating impeller, not grind it. When the pump stops the sand contained in suspension in water, precipitates between the impeller and diffuser. The impeller, respectively, falls under its own weight as the basis of hydraulic housing. At cruise operation, particulate matter, with the flow of water passing through the impeller, the first fall on the surface of the cone holder (made of stainless steel), and thus the fixed diffuser vanes are less prone to abrasion.
The submersible pumps are equipped with monophasic or three-phase motors. Monophasic models are equipped with internal thermal protection with automatic reset.