Drag reducing effects of polymer additives on Coal-Water Mixture in rotating disk system

Abstract

Using a rotating disk apparatus, the concept of drag reduction produced by polymer additives is applied to Coal-Water Mixture(CWM) transport. Experiments were undertaken for a wide range of polymer concentrations of poly(ethylene oxide: PEO), poly(acrylamide: PAAM), coal concentrations and rotating disk speeds. Drag reduction decreased with higher coal concentrations, and increased with higher polymer concentrations up to 150 wppm for PEO. Further increases in the PEO concentration led to lower drag reduction. Howere, PAAM produced higher drag reduction which remained almost constant over a wide range of concentrations. The effect of polymer degradation was also investigated and it was found that PAAM is a better drag reducer than PEO when applied to long time transportation of CWM.