Primers of large centrifugal pumps are designed for water conduction or water mechanical elevation. They are installed under conditions of negative suction with the use of ejectors through the creation of vacuum in the system of pipelines and in the pump itself. The adequate ejector is not always used to carry out this work due to the lack of information and technical data. In order to contribute to the solution of this problem, the performance of jet machines driven hydraulically was evaluated. For this purpose, tests were carried out with two types of hydro-ejectors available in the market, with characteristic parameters m=0,35 and m=0,52 respectively, led by a centrifugal pump seeking for the volumes of air and dragged water. The efficiency of these ejectors, the relation suction flow/suction pressure, for several pressures and feeding flows, were previously established. The resuslts obtained clarify the technical knowledge about the performance of such devices and make possible an appropriate choice for their different applications, as well as ideal operating conditions. An equation was developed to evaluate the ejector efficiency.
ejectors; suction pressure; efficiency