Experimental investigation and CFD modelling for enhancing pipeline performance for high concentration fly ash slurry

Abstract

This study intends to thoroughly investigate fly ash slurry transport at high solid concentration using integrated experimental and modelling approaches. To achieve the desired objectives, the rheological properties of slurry with additives were studied, and experimental data were gathered from pilot plant tests conducted both with and without additives at a solid concentration of 50%. Additionally, computational fluid dynamics simulations were performed and validated with the experimental data. Sodium silicate was used as an additive in concentrations ranging from 0.1% to 1.5% w/w. The rheology test demonstrated that sodium silicate impacted the Bingham parameters, optimizing additive concentration at 0.5%–0.6% w/w. Further, using additives at this range optimized the reduction in pressure drop in the pilot plant test, aligning with rheology findings. The computational fluid dynamics simulation utilized the Eulerian two-phase model in Ansys CFX software by adopting seven distinct turbulence models. The pressure drop results were predicted, and it was found that the SSG model concurs highly with the experimental findings. Further predictions were made to comprehend the flow patterns of slurry. This work is beneficial in minimizing the amount of experimental effort needed to accomplish the development of a fly ash slurry pipeline with high concentration.