Effect of Calcium Carbonate Solution on Drag Reduction in a Pentagon Spiral Pipe

Abstract

Calcium carbonate is environmentally friendly substance that has not been widely studied. It is indicated that the powder has the potential to initiate drag reduction. Experimental study was conducted to determine flow behavior and drag reduction influenced by calcium carbonate solution. In this study, pure water-ethylene glycol mixtures with ratio 60:40 were used as the liquid and calcium carbonate 80-100 nmin size as the powder. Variations of calcium carbonate concentration were 100, 300, and 500 ppm, respectively. In the test section, there are pentagon spiral pipe and circular pipe with the same hydraulics diameter. The pressure drop data were obtained by pressure transducer. The correlation between the friction factor and the generalized Reynolds number was determined by the pressure drop and the flow rate data. At the Reynolds number 4 x 104, the maximum drag reduction rate would be over 21.77% by the circular pipe and 30.89% by the pentagon spiral pipe. It was found that calcium carbonate can contribute to drag reduction and used spiral pipe can enhance the phenomenon.