Below enlisted are the seven types of pumps that are used to lift water up in a tank:
- Direct Lift: these are basically the old-fashioned ‘village well’ devices of a bucket and windlass. Roman water-lifting wheels (norias) and the ingenious Middle Eastern counterweighted cantilever known as a shaduf are also direct lift devices.
- Positive Displacement: in this approach, arrays of non-return valves or similar devices are sequentially opened and closed (usually using reciprocating rods or plungers), to repeatedly trap pockets of water and then force them upwards (i.e. ‘positive displacement’). Village hand-pumps in developing countries are typically of this type, including the Nicaraguan rope pump, which now supplies more than a quarter of the population of that country with water.
- Finally, some rotary devices: most notably the Archimedes Screw and Mono pumps – are also positive displacement devices, although they can superficially resemble the next major category.
- Rotodynamic: vanes or impellers spin on an axle inside a cylindrical chamber (known as a volute), speeding up the flow of water through a pipe. The vast majority of high-rate pumps used in industry are of this type.
- Buoyancy Increase: in this approach, a gas (usually just air) is injected into the water column within a pipe, causing lots of bubbles which make the water so low in density that it rushes up the pipe, with the rest of the water following behind. This approach is usually called ‘air lifting’, and is commonly used by water-well drillers to clean out a new well.
- Jet Pumps: the localized pressure drop created by fast-flowing water in a narrow pipe (the Venturi effect) can induce more water to enter the pump chamber from outside. Some water is always recirculated through the pump, but the majority is discharged. These types of pumps – often termed ‘ejectors’ – are widely used for construction site dewatering operations, as they have the advantage of having no submerged moving parts, and are thus not very sensitive to abrasion by suspended particles.
- Suction: Also popular in dewatering applications, an engine is operated which creates a powerful suction, and this is then connected to pipes in numerous shallow wells. This approach cannot be used to lift water from depths greater than about 8 metres at sea level, and less still at higher altitudes.
- Impulse: the only common pump in this category is the hydraulic ram, which makes a virtue of the water hammer phenomenon by using repeated slamming shut of a valve by a large flow of water to drive a small amount of water up a rising main. These pumps are very handy in rural areas without electricity, as the power of the flowing water alone is all that is needed to pump the water. However, you do need to locate them far enough from housing to make sure the perpetual banging noise doesn’t drive everyone mad.
We hope the explanation of these pumps will give you a better understanding of working culture of your water suppliers and how do they maintain regular water flow to all their users’ homes. If you still have any queries or concern regarding the water supply in your home, feel free to call them at Northumbrian Water Contact Number and get all your queries answered by their team of experts.