Solid-liquid mixture flow through a slim hole annulus with rotating inner cylinder

An experimental study was conducted to study solid-liquid mixture upward hydraulic transport of solid particles in vertical and inclined annuli with rotating inner cylinder. Lift forces acting on a fluidized particle play a central role in many important applications, such as the removal of drill cuttings in horizontal drill holes, sand transport in fractured reservoirs and sediment transport, etc. Annular fluid velocities varied from 0.4 m/s to 1.2 m/s. Effect of annulus inclination and drill pipe rotation on the carrying capacity of drilling fluid, particle rising velocity, and pressure drop in the slim hole annulus have been measured for fully developed flows of water and of aqueous solutions of sodium carboxymethyl cellulose (CMC) and bentonite, respectively. For higher particle feed concentration, the hydraulic pressure drop of mixture flow increases due to the friction between the wall and solids or among solids.