Extension of Solid Particle Erosion Models for the Calculation of Erosion of Pneumatic Equipment Due to Pulverized Coal

Abstract The application of a state-of-the-art erosion model applied to the problem of erosion of pneumatic transport hardware at Pulverized Coal (PC) Power stations was previously examined and it was demonstrated numerically that erosion is being over-predicted by a factor of about 100. In this paper, jet-impingement experiments are performed using sand and coal for a development of a novel erosion model and Computational Fluid Dynamics (CFD) is used for verification and validation of the model. This work is a result of the last two years collaboration between RJM Corporation and the Erosion/Corrosion Research Center (E/CRC) at the University of Tulsa. To accomplish the research, one experimental test facility capable of testing sand, PC, or a mixture of sand and PC was designed and fabricated. In parallel, pulverized fuel were sourced, tested (proximate and ultimate), minerals characterized, and particle distribution determined. Using the new erosion facility, experiments were accomplished that demonstrated the sudden change in erosion rate (ER) as a result of an increase in particle concentration. Additional experiments allowed for characterization of the erosion phenomena and an empirical correlation was developed and is presented in the paper. The coal was examined using Mineral Liberation Analysis (MLA) for two different particle sizes. The larger size particles were shown to have a high percentage of mineral matter distributed into the particles and smaller particles had significant “free” minerals. Testing showed that the small particles with high amounts of free minerals had a nearly ten-fold increase in ER. Finally, an empirical methodology was developed to account for variations in mineral properties. When applied to the coal analyzed, predicted material losses decreased by a factor of ten. The aggregate of the three corrections is shown to bring erosion material loss calculations closer to the approximate life expectancy (2–4 years) observed with the commercially utilized PC nozzle.