Shou, G 2005, 'Laminar Flow – Possible Pipeline Operating Mode', in R Jewell & S Barrera (eds), Paste 2005: Proceedings of the International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 45-52, https://doi.org/10.36487/ACG_repo/563_3
Slurry pipeline designers usually state that the operating velocity of a slurry
pipeline should be higher than the transition velocity. In other words, laminar
flow is not allowed in a slurry pipeline. The major concern is the potential of
pipeline plugging. When designing a thickened tailings or paste pipeline, the au-
thor found that the operating cost would be prohibitively high if this rule is ap-
plied. A literature research and a loop test show that laminar flow is feasible
under certain conditions.
The transition velocity of a slurry flow can be calculated based on the slurry
viscosity, yield stress and pipeline ID. When the operating velocity is lower than
the transition velocity, a solids bed may form on the pipeline bottom. The depth
of the solids bed and the pipeline effective ID varies depending on the flow rate.
This self-adjusting nature of slurry flow in pipeline allows us to operate a pipeline
in a wider range and save the capital and operating costs significantly.
The potential of pipeline plugging is different from one pipeline system to
another. Therefore, it should be evaluated for each individual thickened tailings
46 Paste 2005, Santiago, Chile
Laminar Flow - Possible Pipeline... Shou, G.
Hanks, R.W., and Dadia, B.H. (1971) Theoretical Analysis Of The Turbulent
Flow Of Non-Newtonian Slurries In Pipes, AIChE Jnl.
Song, T. and Chiew, Y-M. (1997) Settling Characteristics of sediments in moving
Bingham Fluid, J of hyd. Eng, Vol. 123, No. 9, ASCE.
Gillies, R.G., Hill, K.B., McKibben, M.J. and Shook, C.A. (1999) Solids Trans-
port by Laminar Newtonian Flows, J. Powder Technology.