In my area iron & fine sand contents are found maximum in bore wells. Which type of impellers in pumps are durable?
One way to contain abrasive wear is to use slow-speed pumps. In coal mines they have been using helical rotor progressive cavity (HRPC) pumps as face pumps. The liquid is very much similar to what you find in the borewells there. Wear due to sand and coal fines is different from wear due to slurries like tooth paste or ash slurry. Sand particles would impinge on to the surface with a steep angle of incidence, whereas slurries will abrade the surface moving very close and parallel to the surface. Wear due to impingement can be better tackled by resilient materials like rubber. Conversely abrasion needs hard surfaces. Effect of impingement will be less severe at slow speeds. HRPC pumps inherently have an elastomer-lined stator. They are also positive displacement pumps and hence can pump from any depth. They are inherently slow speed machines. HRPC pumps have been made in India to inject sea water into oil wells to improve the productivity of the wells. And the depths reached are 1000m 1
