Experimental investigation is conducted to study the flow characteristics of a 2-phase vertically upward hydraulic transport of 2 types of small solid particles of nearly identical specific gravity and size in a clear, smooth-surfaced, PVC pipe of I-in (2.54 cm) diameter: Irregular-shaped silica sands and equivalent spherical glass beads. The emphasis of the investigation is placed on the shape effect of particles on the pressure gradients and flow rates. Pressure drops and mass as well as volumetric flow rates were measured by 2 types of flowmeters: electromagnetic (EM) flowmeter and mass flowmeter. The particle sizes used are 30–40 mesh and 8–10 mesh. The results over a turbulent flow range of 104< Re < 105 show the pressure gradients or friction factors are smaller for the spherical glass beads than the irregular-shaped sands. The larger the size of particles is, the larger the shape effect on the pressure gradient becomes, and the more distinct the effect of the particle shape becomes at lower particle concentrations. The larger the size and concentration of the particles are, the larger the pressure gradients become. The larger the particle concentration is, the less the effect of particle shape on pressure gradients becomes. The shape effect is greater for the minimum particle transport velocities than for the settling velocities.
The present experiment series is to investigate various effects for vertical 2-phase mixture transport and flow characteristics of the particle-water mixture. Its ultimate purpose is to model a vertically upward hydraulic transport system to produce solid particles or solids in alluvial form, including heavy mineral particles from the deep-ocean floor. The present results come from one of the first series of experiments with a 1-in-diameter test loop. Among the many experiments of the vertical particle-water mixture flows that were previously conducted for the vertical hydraulic transport of solid particles,
