The influence of salinity of fly ash mixtures on energy looses during flow in pipelines

Abstract

In Polish mining for backfilling the fly ash mixtures are used. Last time for fly ash mixtures preparation the saline water from mine have been used, to thanks to that the saline water missing the surface waters. Usage of saline water for fly ash mixture preparation causes the changes in energy looses during the flow in pipelines. The paper presents the results of energy looses measurement іn laboratory pipeline installation with diameter D = 50 mm. The measurements have been performed for different fly ash – saline water proportions. Tested fly-ash from Siersza power plant has typical properties (grain size distribution curve, density) for ashes used for backfilling mixtures preparation. Increase of fluid (water) salinity modifies fluid viscosity. Brine in comparison with pure water retains as liquid with increased viscosity. Increased viscosity can influence on the mixture ash-brine properties for example causing flocculation effect. Also changeable salinity has an influence on proper determination of resistance (frictional) coefficient λ during mixtures flow in pipelines because it depends on Reynolds number which depends on liquid viscosity. Increase of fly-ash concentrations in fly-ash – brine mixtures cause increase of energy losses.