Discrete element method and experiments applied to a new impeller blade design for enhanced coverage and uniformity of shot blasting

摘要

Shot blasting is the process of exfoliating the surface of a substance to remove scales or impurities. Shot blasting can be classified into two categories based on the type of material used: air-blowing and impeller-impact types use air and shot balls, respectively. For impeller-type shot blasters, coverage and uniform distribution are more critical than residual stress for the purpose of scale removal. In this study, the discrete element method is used to analyze the coverage and uniformity of the impeller-type shot blasting process with a very large number of shot balls. To enhance coverage and uniformity, filleted and bulged blade designs are proposed and evaluated by discrete element method (DEM) simulations and the amount of fillets and bulges is optimized, realizing an efficiency increase of up to 20%. Shot blasting experiments using bulged blades also show good agreement with results obtained using the discrete element method.