Application of an electric field to enhance the flow of coal-water slurries in pipelines

Electrokinetics involves the movement of charged particles or water molecules in an applied dc field. Applications in particle fluid systems include the dewatering of soils, the densification of mill tailings and the treatment of coal wastes. In this paper, a novel application of this technique is discussed, wherein an electric field is applied to a coal-water slurry flowing through a pipe, resulting in lower pressure losses in the system. A unique experimental setup was designed and built to study the effect of an electric field (dc) on the wall shear stress for the flow of coal-water slurry through the pipe. The effect of solids concentration, current strength and pH on drag reduction across the system was quantified.