Performance Evaluation of a Centrifugal Pump with different Impeller Materials

Abstract

Abstract Many factors affect the performance characteristics of a pump. One of these is the impeller material. This paper is on the effect of impeller material on the operating characteristics of a centrifugal pump. The impeller materials used were cast iron, bronze and zinc. Cost, pumping efficiency, pressure head and power consumption are the factors that were taken into consideration. The results from the test, showed that the impeller made of zinc material was found to be more efficient (48.24%) and required the most power (3.38bhp). The zinc impeller was the least expensive to manufacture and pumped better head. The zinc impeller however failed at (very) high pump speed due to the fact that its strength could not match up with the pump speed. The cast iron impeller on the other hand, required the least power (0.86bhp) to run but pumped the least head (6.25m) and was more efficient (46.35%) than the bronze impeller; this was majorly due to cavitation and friction losses. The bronze impeller pump was the least efficient (38.79%), the most expensive to manufacture but pumped more head (8.50m) than the cast iron impeller and required more power (2.32bhp) than the cast iron impeller.