DESIGN, CONSTRUCTION AND MEASURED PERFORMANCE OF A SINGLE-STAGE CENTRIFUGAL PUMP DEMONSTRATION UNIT

Abstract

The design philosophy, construction and measured performances of a single stage, single entry centrifugal pump demonstration unit are presented. In the construction, close-coupled induction motor drives the centrifugal pump, which draws fluid (water) from a water storage tank and delivers same through a flow control valve, and an orifice meter, back to the tank. Changing the setting of the flow control valve alters the system resistance, and so changes the operating point on the pump’s head-flow characteristics. Piezometers are attached to the pipe work, close to the inlet and outlet of the pump, so that the total head-rise (H), is recorded by a pressure gauge. A further measurement is made of the differential head, h across the flow meter, from which the flow rate, Q is inferred from the meter-calibration. The demonstration unit was used to run the tests necessary to fully characterize a centrifugal pump. Tabular and graphical representations of the relationships between the various parameters, viz: head (H), efficiency (?), rotational speed (?), and input power (P_i)_, with the flow rate (Q), were generated. The experimental results obtained with the demonstration unit shows that the tested pump can develop a maximum head, (H_max) of 18.35m, maximum flow rate, (Q_max) of 21.40 litres and maximum speed of 2800 rpm for an input power (h.p) of 0.5 (370watts).