Development of a priming instrument for centrifugal pumps

In Egypt, surface irrigation is the most commonly used method comparing with the other irrigation systems in old land. In addition, centrifugal instruments are prevailing used for irrigating fields. However, the major problem who confronts the farmers at operating these instruments is priming it to be operating by filling the water to replace the air in pipes. To be prime the instrument need two men and consumption about 20 to 30 minutes at best conditions, if the foot valve of suction pipe is good. Nevertheless, when the foot valve is breakdown this operation need more time and efforts. To be solvent this problem developed a priming instrument was developed to full the water in suction pipe of centrifugal pump mechanically. Moreover, this develops help and makes the job easily when the pump attachment to gate pipe irrigation method. The objective of the present investigation is to develop and evaluate different methods for priming of centrifugal pumps. The performance was evaluated under the following parameters: A. Three sources motion of priming (manual reciprocating motion, manual circular motion and mechanically motion). B. Three air suction orifice diameters (2.5, 3.75, 5.0 and 6 cm). C. Two suction pipes, with and without foot valve. The best results were achieved by using mechanically circular motion without foot valve and air suction orifice diameter from 3.75 to 5.0 cm gave the lowest time consumed in priming the centrifugal instrument. * Chief Researcher Institute of Agric. Eng. Center of Agric. Researches, Egypt. ** Senior Researcher Institute of Agric. Eng. Center of Agric. Researches, Egypt.