Numerical investigation of Bi-model slurry transportation in a straight pipe

Abstract

Slurry transportation through a pipeline system is a conventional mode of conveying solid material, which several industries have adopted across the globe. However, this mode of transportation is a complex phenomenon that requires high suspension stability of the particulates and high-energy requirements to deliver the solid materials continuously. Further, the researchers have adopted various techniques to make the continuous flow of solid materials through pipeline systems, such as additive addition and increasing the percentage of fine particles in the mixture. However, the accurate bi-model for the transportation of solid materials is not yet established. Therefore, in the present work, different mixture ratios (65:35, 75:25, 85:15 and 95:05) of silica sand and fly ash are considered to investigate the slurry flow characteristics. A numerical investigation is carried out for a bi-model slurry flow of silica sand (2650 kg/m3) and fly ash (2100 kg/m3) particulates having a mean diameter of 450 and 75 μm through a horizontal pipeline of 0.0549 m diameter. The accuracy of the numerical model and the procedure adopted for the current simulation is also validated by the available results in the literature. The work's outcomes reveal a significant drop in pressure with the increase in the percentage of fly ash in silica sand slurry. Further, the contours of the solid concentration, velocity distribution, granular pressure, granular temperature and wall shear stress are also envisaged and discussed in detail to analyze the effects of fly ash in silica sand slurry. Furthermore, Specific energy consumption is also calculated from the empirical relation for the different silica sand and fly ash ratios. The calculations show that the slurry mixture of 35% of fly ash in 65% of silica sand requires the least energy for transportation.