Performance optimisation of manual suction water pumps

Abstract

Proper use of water entails efficient methods of water lifting for domestic and irrigation use. Irrigation in most parts of Africa depends mostly on manual lifting methods and conventional motorised pumps, which are expensive. Apart from the high operating cost of motorised water pumps, the cost of spare parts and availability makes them unreliable to most farmers in Africa. Similarly the size of land to be irrigated, which is mostly small, makes investment on motorised water pumps expensive and therefore uneconomical. On the other hand the per capita income of most peasant farmers are very low, the return on investment is quite low and therefore the ability to invest on the farms is quite low. The farmer in Africa needs an efficient low cost water pumping technology that guarantees low cost of investment and hence low risk. Tests were performed for different suction valve diameters and cylinder diameters for total pumping heads of 4m, 6m, 8m, 9m, 11m and 14m with alternate suction and pressure heads of 2m, 4m and 7m with a fixed suction pipe internal diameter of 29mm. The pump cylinder diameters used in the tests are 35mm; 46mm and 54mm with suction valves diameters of 10mm, 15mm, 20mm, 25mm, 30mm and 35mm.The data collected were the time taken and the number of strokes to fill a 20 litre container for the test configurations.