Experimental study of hydraulic transport of large particles in horizontal and S-shape pipes

Florent Ravelet (1) , Farid Bakir (1) , Sofiane Khelladi (1) , Robert Rey (1)

1 DynFluid - Laboratoire de Dynamique des Fluides

We study the pressure drop and flow regimes for a two-phase liquid and solid mixture that flows in a horizontal pipe and in a vertical S-shaped pipe. Two densities are used for the solids. The solids are spheres that are large with respect to the diameter of the pipe (5, 10 and 15%) or real stones of arbitrary shapes but constant density and a size distribution similar to the tested spherical beads. Finally, we study mixtures of size and / or density. The regimes are charaterized with differential pressure measurements and visualizations. The results show that the grain size and density have a strong effect on the transition point between regimes with a stationary bed and dispersed flows. The pressure drops are moreover smaller for large particles in the horizontal part. In order to match the pressure drop measurements, empirical models based on a Froude number are tested, together with 1D models that are based on mass and momentum balance. Finally, compared to vertical geometries, the pressure drops in horizontal pipes are significantly lower, but the critical velocities with respect to plugging are higher.

Domaines: Dynamique des Fluides [physics.flu-dyn]

Florent Ravelet, Farid Bakir, Sofiane Khelladi, Robert Rey. Experimental study of hydraulic transport of large particles in horizontal and S-shape pipes. 2011. ⟨hal-00631562v1⟩