Centrifugal pump performance derating with non-Newtonian slurries

Centrifugal pumps are widespread and consolidated machines to transport fluids in industry. In certain fields, such as biomedical, food, and oil and gas, non-Newtonian fluids have to be managed. The viscosity of a non-Newtonian fluid varies with the imposed stress and rheology, and consequently, pumping this type of fluid can lead to a considerable variation in the pump performance. The pump performance is usually provided by manufacturers only with water and thus, the selection of the proper machine to handle non-Newtonian fluids could be very tricky. Several models are found in the literature to predict the performance of centrifugal pumps with this type of fluids but a lack of reliability and generality emerges. Moreover, previous experimental investigations reported that sudden performance ascribed to gas-locking phenomena is detected at part-load operations. To avoid safety issues, oversized pumps are commonly installed, thus increasing the installation and operational costs. In this work, a small centrifugal pump was tested against a set of non-Newtonian slurries with different solid concentrations on an on-purpose test loop. The resulting performance is employed to assess the prediction quality of a derating method from the literature.