Difference between revisions of "Rope pumps"

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==Why==
 
==Why==
*Industrial (donated) hand pumps for communal wells often break down after two years. If cost for maintenance is born by the users, development projects may donate a robust industrial pump such as the Indian Mark II. In practice this cost is too high when repairs prove necessary.
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*Industrial hand pumps, such as the Indian Mark II, for communal wells donated by development projects often break down after two years. If maintenance costs are born by the users this cost is too high when repairs prove necessary and the pum is left nonfunctional.
*An alternative reliable hand pump is also needed for private use and to irrigate gardens. Next to communal pumps, pumps on private wells could raise the standard of living if they were low in cost, reliable and lift water effectively. To irrigate a garden in the dry season to increase income can only be realized if such a hand pump converts human energy with little loss in water lifted.
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*An alternative reliable hand pump is needed for communal and private use to supply clean drinking water and irrigation. These will raise the standard of living if they are low in cost, reliable and lift water effectively. Efficiency is critical to irrigate a garden in the dry season due to the relatively large amount of water involved.  Such gardens provide food and increased income.
*Local affordability and local maintenance is a must, together with an excellent pump performance. Local affordability asks for a cost reduction compared to imported industrial goods in a twenty to hundred fold way. Local maintenance is only possible when local craft or the future user can have constructed the pump.
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*Local affordability, maintenance an pump efficiency are required features. Local affordability results in a twenty to hundred fold cost reduction compared to imported industrial goods. Local maintenance is only possible when made with local resources and skills.
*A pumping system should allow full closure of a well against contamination of drinking water. This specially regards pumps on communal wells. Industrial pumps need to be bolted on to a concrete slap, positioned over the well. But this makes the water in the well inaccessible in case of break down of the pump. A solution is immediate maintenance being available or access to the well through an emergency hatch.
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*The pumping system should prevent contamination of drinking water by permitting the well to be sealed. This is especially true of communal wells. Industrial pumps need to be bolted on to a concrete slab positioned over the well. However, this makes the water inaccessible when the pump breaks down. Immediate maintenance on the pump or access to the well through an emergency hatch permits continuous access to lifegiving water.
  
 
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[[Image: RP_UpperConstruction250.gif|right|frame|]]

Revision as of 04:30, 22 December 2006

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Why

  • Industrial hand pumps, such as the Indian Mark II, for communal wells donated by development projects often break down after two years. If maintenance costs are born by the users this cost is too high when repairs prove necessary and the pum is left nonfunctional.
  • An alternative reliable hand pump is needed for communal and private use to supply clean drinking water and irrigation. These will raise the standard of living if they are low in cost, reliable and lift water effectively. Efficiency is critical to irrigate a garden in the dry season due to the relatively large amount of water involved. Such gardens provide food and increased income.
  • Local affordability, maintenance an pump efficiency are required features. Local affordability results in a twenty to hundred fold cost reduction compared to imported industrial goods. Local maintenance is only possible when made with local resources and skills.
  • The pumping system should prevent contamination of drinking water by permitting the well to be sealed. This is especially true of communal wells. Industrial pumps need to be bolted on to a concrete slab positioned over the well. However, this makes the water inaccessible when the pump breaks down. Immediate maintenance on the pump or access to the well through an emergency hatch permits continuous access to lifegiving water.
RP UpperConstruction250.gif
RP InWellConstruction250.gif

How

  • Low cost modern materials as plastic pipe and rope are used in a rotating hand pump system. In the working principle of the chain pump the chain is replaced by rope and the rotating chain drum by a specially constructed rubber disk wheel. Such a rubber wheel can be made from used car tires. Other additional needed materials can be found at little or no cost.
  • Little time is needed to instruct users or craftsman to construct a rope pump. People adapt the basic principle to their own needs, be it shallow or deep wells and bore holes, or horizontal pumping from a pond. To achieve quality, instruction should center on making understood the relation between wheel diameter and the diameter of the plastic pump pipe. Crucial is the correct construction of the place where the rope movement changes direction from downwards to upwards in the bottom of the well.
  • If instructions regarding quality are followed, the water water gift of the rope pump outclasses the traditional pump by far. The Demotech Rope-pump is superior by far in all aspects of use, as well as price per unit, when compared to other types of hand-pumps. *Further development could mean cutting the cost-price per unit in half, making it suitable for 100m-holes, quick and efficient maintenance, robust construction and housing, as well as more-efficient propulsion and higher efficiency.
  • The rope pump can be adapted to a special situation. To make it suitable for being mounted on a well cover the bearing of the pump axle is positioned at one side of the pump wheel only. In most other set-ups it is preferred to have the bearing on both sides of the pump wheel, better even: at both the very ends of the axle and handle.

See also