Performance evaluation of a regenerative pump under fluid viscosity enhancement
Keywords:Regenerative pump, Low specific speed, Viscosity, Polyacrylamide (PAM), Performance curves
AbstractRegenerative flow pumps are kinds of dynamic pumps with the ability to develop high heads at low flow rates. Despite the disadvantage of having low hydraulic efficiency, regenerative flow pumps have found many applications in industries. In this paper, the effect of fluid viscosity on the performance of regenerative pump has been investigated experimentally. The primary fluid was water with viscosity of 1 centipoise. Polyacrylamide (PAM) which is a soluble polymer in water was used to increase the viscosity of fluid. Solutions prepared from dry powder PAM at two concentrations of 1600 ppm and 2400 ppm. Solutions were pumped more than 30 times to have homogeneous fluids. The measured viscosities for these two solutions were 180 and 300 centipoise respectively. Results showed that as flow coefficient reduces, the decline in head coefficient gradually increases. Similarly, it was found that viscosity enhancement reduces the power coefficient. There was not any significant change in efficiency curves at low flow coefficients. In contrast, around design flow coefficient and at high flow coefficients, the hydraulic efficiency of the pump reduced by increasing viscosity of working fluid.
MECHANICS OF FLUIDS AND GASES