ABSTRACT
In order to minimise energy costs it is frequently desired to operate hydraulic transport lines at the lowest velocities necessary to avoid significant solids settlement. Although the presence of a sliding or stationary bed of solids will increase the line operating pressure for a given volumetric throughput, instrumentation designed to monitor the latter two parameters may be inadequate to detect settlement until solids build-up has reached dangerous proportions, particularly where relatively large and heavy particles are involved. Also, an increase in line pressure due to settlement may be erroneously interpreted as a change in the viscosity of the slurry caused by variations in solids concentrations or size distribution. For these reasons, an independent indication of the presence of a settled bed would be desirable. Techniques suitable for detecting a bed of settled solids in the pipeline have been investigated by Kazanskij (21), Ercolani et al. (28), Ferrini et al. (29) and Brown and Shook (30).
