Calculation model for drag coefficient and multi-phase flow characteristics in dust removal process: Comparison between flake aluminum powder and spherical aluminum powder

It is of great significance to study the force model of flake and spherical particles in a two-phase flow system for reducing dust hazards. In present work, the correspondence between drag coefficient C_d and Re for spherical particle is specified by a new CFD method. Moreover, 144 kinds distribution states for flake particle with equal probability are summarized into 7 kinds stress state models with different occurrence probabilities, and the corresponding relationship between the equivalent drag coefficient C_d and the equivalent Reynolds number Re is further obtained. A series of ventilation and dust removal experiments and full-scale numerical simulation in a large space are carried out, and the maximum error of peak dust concentration between the simulation results and the experimental results for flake powder is 17.4%. In addition, the size effect of flake powder is more obvious than that of spherical powder, and the fluidity of flake powder with equal particle size is obviously better than that of spherical powder, so flake powder can be removed from the production workshop faster. However, in the process of ventilation and dust removal, the diffusion risk of spherical dust larger than 100 μm do not change much during the ventilation process.