Rope pump
A rope pump is a kind of pump where a loose hanging rope is lowered down into a well and drawn up through a long pipe with the bottom immersed in water. On the rope, round disks or knots matching the diameter of the pipe are attached which pull the water to the surface.
Description
A rope pump is a kind of pump of which the main or most visible component is a continuous piece of rope, in which the rope is integral in raising water from a well. Rope pumps are often used in developing areas with the most form consisting of a PVC pipe and a rope with flexible or rigid valves. Rope pumps are cheap to build and easy to maintain. One design of rope pump using a solar-powered rope pump can pump 3,000 litres per day using a 80 watt solar panel .[1] Rope pumps can be powered by low speed petrol/diesel/engines, electricity,[2] human energy,[3] wind[4] and from solar.[1]
History
Chain or washer pumps were used by the Chinese over 1000 years ago[5]. In the 1980s Reinder van Tijen an inventor and grass roots activist, with the support of the Royal Tropical Institute of Amsterdam, created and began instructing various communities around the world how to make a rope pump from simple available parts using PVC pipes and plastic moldings. He began at Borkina Faso in Africa, continued to Tunisia, Thailand and Gambia among others[6]. In Nicaragua, the technology was rapidly disseminated over the whole country and 25% of the rural population in Nicaragua now use rope pumps. It is also used in other parts of Central America with over 25,000 pumps installed to date[7]. In Africa the rope pump is now being used with solar energry.[1] By the end of 2009 more than 4 million people in 20 countries worldwide were using rope pumps for domestic and irrigation water.
Construction
Rope pumps can use flexible valves, rigid valves or sometimes no valves at all. Flexible valve can be cut piece of bicycle tube. The valves are positioned 20 cm apart on the rope. One disadvantage of flexible valve rope pumps is that different pump builders may use inappropriately sized valves. The thickness of the rubber is also an important factor that differs from place to place.[8] Rigid valves using plastic or metal washers that fit tightly into the PVC pipe as the rope is dragged through can also be used. If the fit is tight, the washers can be spaced up to half a metre apart. For deeper wells, thinner pipe can be used. These rope pumps often work with a hand crank.[9] Valves can also be made from knots in the rope itself.[10] Valveless pumps rely on friction with water clinging to the rope is moved at high speed, often using a bicycle to produce the required speed. It is a less efficient design but is simpler to construct.[3]
Rope pump technology is in the public domain and there are no patents pending on it.[5]
See also
References
- ↑ 1.0 1.1 1.2 "Solar powered water pump". Solar Aid. http://www.solar-aid.org/project_water_pump/. Retrieved on 2009-04-10.
- ↑ "Moto Rope pumps". http://www.daenvis.org/ropepump9.htm. Retrieved on 2009-04-10.
- ↑ 3.0 3.1 "Bicycle Rope Pump". http://www.thefarm.org/charities/i4at/lib2/ropepump.htm. Retrieved on 2009-04-10.
- ↑ "THE ROPE WIND PUMP". http://www.gamos.demon.co.uk/just%20gamos%20homepage/henkfnl2.htm. Retrieved on 2009-04-10.
- ↑ 5.0 5.1 "history". Ropepump.com. http://www.ropepump.com/his/his.htm. Retrieved on 2009-04-10. Rope pump history including 16th century image of the Chinese chain pump
- ↑ The man outside the box On Van Tijen at Crossroads magazine website. The site includes some clear images of the invention and how it works.
- ↑ Cite error: Invalid
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- ↑ http://web.archive.org/web/20091026235138/http://www.geocities.com/ResearchTriangle/System/7014/rope.html
- ↑ Appropedia:Rope pump knots