Since its inception, the Development Technology Unit has undertaken research into a number of water lifting devices both for irrigation and for drinking water. More recently we have been researching very low cost pumps for water extraction from rainwater harvesting tanks.
Between 1985 and 1997, the DTU researched and developed several hydraulic ram pumps. Partly funded by the Overseas Development Administration, the aims of the programme were:
- To analyse in detail the operation of the ram pump gaining a comprehensive understanding of the operating principles and complex hydraulic interactions occurring within the pump.
- To produce pump designs suitable for manufacture in developing countries using available materials and production processes.
- To thoroughly test such designs for their performance and endurance (including extensive field trials) and offer findings for widespread dissemination.
- To develop and prove methods for surveying and design of complete water supply installations.
- To produce design charts and computer based tools to enable design and field engineers to confidently include hydraulic ram pumps as an option in their water supply schemes.
- To provide technical expertise and training for two African based programmes installing ram pumps for village water supply and irrigation.
In terms of hardware development the DTU had two distinct working areas. The first was the development of designs of steel hydraulic ram pumps based on the 1" and 2" diameter BSP pipe been found to be widely available in developing countries and an appropriate capacity for small village water supply schemes. The second area of hardware development was the production of plastic hydraulic ram pumps based on widely available 110mm plastic pipe and especially suitable for irrigation close to water courses.
As well as several DTU publications, the work resulted in a book by DTU members on ram pump water supply systems: Jeffery TD, Thomas TH et al, Hydraulic Ram Pumps: A guide to ram pump water supply systems, Intermediate Technology Pubs, London, 1992, ISBN=1-85339-172-7, 135pp available from ITDG Publishing
Treadle pumps are a human operated pump powered by the operators feet. The DTU has researched such issues as power matching, pump efficiency and design simplification.
Low cost tank extraction pumps
Several of the DTU's designs for rainwater harvesting systems use underground tanks, requiring a pump to extract water. To this end the DTU has developed several very low cost pumps based on PVC pipe. Work continues on these pumps which are also suitable for low head ground water extraction.