Using the Ocean to Fight Climate Change Raises Serious Environmental Justice and Technical Questions
December 29, 2009
Five water pumps: Design ideas and how-to’s
contributor: Rob Goodier
Water pumps that are easy to build and maintain are a cornerstone of sustainable water supplies and yet this technology is still missing from parts of the developing world. We’ve flagged videos on our YouTube channel that show five kinds of water pumps in action. Some show how to build the pumps, others demonstrate the concept. The pumps have few – and in one case no – moving parts; they’re made from common, inexpensive materials and they are easy to use and maintain. Many of these were first collected at Approvideo, a video library of appropriate solutions for development.
Brian White, who showed us how to build a sun-tracking solar barbecue out of scavenged junk, also has a solution for pumps. The pulser’s clever design combines two simple technologies and has no moving parts. The engine is a trompe, a gravity-powered air compressor. It pushes air and water through an airlift pump, which is little more than a well-placed vertical pipe. The video shows diagrams and a working pump at a home in Ireland.
Hydraulic ram pumps
Hydraulic ram pumps, like pulser pumps, use gravity and water to compress air and pump water uphill. This video, by the Dutch Demotech Foundation, shows animated diagrams of the pump’s innards and a model on a trough in Maastricht, the Netherlands. As the narrator says, rivers are hard to come by in the Netherlands.
Close-up shots of another hydraulic ram pump in this video are interspersed with pans of a pine-forested valley in Alberta, Canada.
Play pumps, as the video demonstrates, are kid powered. The school children playing on rigged merry-go-rounds at recess are actually pumping water. This video shows an interview with Sandra Hayes, a manager of Play Pumps International. You’ll see how the pumps work and hear about the advantages of installing them on playgrounds.
This short video demonstrates a foot-powered pump used to irrigate a field in a village in Malawi. It’s not a how-to, but it shows the concept (complete with “oohs” from the cameraman). Called treadle pumps, the machines reportedly pump up to 1,300 gallons (5,000 liters) of water per hour from as deep as 25 feet (eight meters). They can be used where aquifers are shallow. Their operating pedals look something like a stair-stepping machine and the whole pump can be made from locally available materials for less than $10.
Rope pumps are a 2,000-year-old technology first used by the Chinese, according to development organization Pump Aid. They use a pulley system to pass a rope through a pool of water and up inside a pipe. The rope is studded with disks that push the water up the pipe. Pump Aid provides animated diagrams of the device at work and shows how rope pumps are used in a village in Zimbabwe.
Do you have a pump design to share, or have you come across a good video? You can let us know by leaving a comment below.