Experiments with concentrated slurries of particles with densities near that of the carrier fluid

Experimental investigations of headlosses and particle velocity distributions have been undertaken for water slurries of polystyrene particles of diameter d 50 = 0.3 and 1.4 mm. At concentrations greater than 40–45% by volume, nearly linear headloss vs. velocity relationships were obtained. These suggested laminar flow but the particle velocity measurements showed the flow to be turbulent. The results have been interpreted with an approximate theory based upon lubrication mechanics. The investigation illustrates the limitations of slurry viscometry in predicting pipeline behaviour for slurries of particles of this size.