By Kimberly Duncan
ECHO Asia Intern
The treadle pump consists of two parts, the pump and the operating mechanism. The pump is generally made of metal and has two cylinders that are connected to a suction pipe at the base and an outlet spout at the surface. The operating mechanism is made up of metal, bamboo, or wood foot pedals that are attached to a superstructure that the operator can hold onto for support. As the operator of the pump shifts their weight on the foot pedals, plungers inside the cylinders reciprocate the motion and draw water alternately into each barrel. Non-return valves protect the inlet and also allow the plunger to move down through the water in the cylinder on the downward stroke without forcing it back down the suction pipe. The upward movement of the plunger lifts the water in the cylinder out the spout and simultaneously draws more water into the barrel of the suction pipe. The water is either lifted onto the field directly, into a pond or into an irrigation canal. (Palumbo)*
Both pumps can lift water from standing water or wells. In both cases the distance from the water source or depth to the water table will affect the amount of water that can be brought up and at what rate. (Most treadle pumps can draw from a maximum 7 meters depth.) In the case of a treadle pump, the size of the piston cylinders and the draw length of the pistons themselves will also determine volume. Cylinders on the UHDP pump are 101mm in diameter; stroke length about 250mm. The bicycle pump sourcing water from the pond is currently functioning at 12 liters per minute. I’m told that the treadle pump, when completed, should be able to pump 30 liters per minute from the same pond.
FAO TREADLE PUMPS FOR IRRIGATION IN AFRICA
FAO - HOW TREADLE PUMPS WORK (continuation of publication above
FAO TECA BAMBOO TREADLE PUMP INDIA
FAO TOTAL LAND CARE - TREADLE PUMP IRRIGATION
FAO REPOSITORY SITE WITH MULTIPLE PUBLICATIONS
THE ASHDEN AWARDS FOR SUSTAINABLE ENERGY
COOPER-HEWITT - DESIGN FOR THE OTHER 90%
*Palumbo, Jamie. "Treadle Pumps." Climate Lab(beta). Creative Commons Attribution Share Alike, 31 March 2010. Web. 11 Aug 2011. http://climatelab.org/Treadle_Pumps.