Experimental Investigation of the Effects of Hydrophobic Impeller Surfaces on the Centrifugal Pump Performance

Abstract

Increasing daily demand for electricity due to population and industrialization makes it necessary to use our existing energy more efficiently. Therefore, in this study the effects of the hydrophobic surfaces obtained by coating the impeller of a centrifugal pump without change its design were experimentally investigated to improve the pump capacity and efficiency. The wet surfaces of the impeller of a centrifugal pump were coated by the total 3 different polymer composite materials-based carbon aspoly tetra fluoro ethylene (PTFE), fluorinated ethylene propylene (FEP) and perfluoro alkoxy polymer (PFA). The hydrophobicity of the coated surfaces was determined by measuring the contact angles respectively as 95 degrees, 105 degrees and 110 degrees. The performance curves of the pump were experimentally determined, and the hydrophobic impeller surfaces reduce the pump specific speed by about 10% compared to the uncoated conventional impeller. Therewithal, it was determined about 10% increase in head-flow rate capacity and respectively 4%, 5%, 5,3% increases in efficiency of the PTFE, FEP and PFA coated impellers.