Effects of non-Newtonian mineral suspensions on the performance of centrifugal pumps

摘要

Experimental results were obtained with variousindustrial suspensions with densities of 1100 to 1600 kg/m~3using a 0.15 by 0.1 m four-vane centrifugal slurry pump with animpeller diameter of 0.63 m operating at 650-850 rpm. The non-Newtonian behaviour for a fixated scrubber sludge and a red mudproduct was characterised in pipeline loops with diameters of0.075 - 0.2 m. The lowering of the pump water head and efficiencyat the best efficiency flow rate region was at a maximum about 10and 20 percent, respectively. With the scrubber sludge, a sharpreduction in head occurred at flow rates below 40 percent of thebest efficiency value, resulting in an unstable head curve. Thisresult is used to demonstrate the risk of unstable operation if aNewtonian correction procedure with a high viscosity is appliedgiving very large reductions in efficiency and a shift of the bestefficiency point to smaller flow rates.