Performance Characteristics of Centrifugal Pumps When Handling Non-Newtonian Homogeneous Slurries
The change in performance characteristics of centrifugal pumps when handling fine granular or homogeneous type non-Newtonian slurries has been investigated using two different slurry pumps handling mixtures of coal/water and kaolin/water. A test loop was used which allowed pump performance to be determined at various pump speeds, with many different mixture concentrations and rheologies. The test work indicated two main changes in the pump performance compared to the water characteristics: (i) a large drop in pump developed head at low flowrates (creating an unstable curve), and; (ii) a reduction in the pump efficiency at flowrates near the best efficiency point. The results show that the pump performance is dependent on the slurry's rheological properties, with pump Reynolds number giving generally good correlation with the change in performance. Methods of performance correlation used for Newtonian fluids were found to give good results provided that a suitable value for the viscosity could be chosen.