| Popis: |
This paper presents the process of virtual prototyping of bulk material preparation devices in mining using numerical simulations of multi-physics phenomena. The discrete element method (DEM), meshless method (MFree), and computational fluid dynamics (CFD) were used in the calculation process. The importance of the extraction process and the practical application of DEM in various industries are discussed. The main contact models between particles and how structural material wear is modelled in DEM are presented. The structure of the computational models in DEM and CFD environments is presented. For the validation of the bulk material computational model, bench tests were carried out to determine the material properties (aggregate: five grades, 0–16 mm; coal concentrate: five grades, 2–32 mm; and so-called raw coal, grade 2–8 mm). The bulk density and angle of natural repose were measured, along with determination of the internal and external friction coefficients. Simulations corresponding to the laboratory tests were carried out. Numerical calculations were carried out for the side chute (results—velocities of the particles, compressive forces in the particles, determination of the wearing process) and for the coke classification line (two lines were assessed according to different aggregate sizes and densities of the bulk material). These multi-physics calculations required a combination of DEM-MFree and DEM-CFD methods. Based on the obtained results, it was possible to evaluate the performance and efficiency of the assessed machines. |
