The Performance of Pump as Turbine with Machined Impellers

Pump as turbine (PAT) is a type of micro hydro power plant, which uses a commercial pump as a turbine in order to generate electricity. Most of PAT facilities used centrifugal pump. The main component of the pump is impeller, which commonly produced by using casting process. However, this paper describes a manufacturing process to produce PAT impeller by using machining process. Four impellers were produced from two variations of materials (brass and AA-7075), each with 5 and 6 blades. The impellers were tested in a laboratory scale PAT power-plant facility, and the performance of each impeller was compared to its original impeller. The experiment results show that the impeller with 6 blades made of brass material improves 48.9% of power generated.