Formação de poeira no empilhamento de materiais a granel
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Data
2022-06-29
Autores
Leão, Rodrigo Xavier de Almeida
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Universidade Federal do Espírito Santo
Resumo
This is a study on the formation of dust that occurs during the stacking of bulk materials. Dust formation occurs by the suspension of microparticles easily transported to the atmosphere and over large distances by low-intensity air currents. Presents authorial methods for modeling and analysis of dust formation, including the development of a Lagrangian Particle Displacement Model (MLDP), analytical solution of the pressure field, computational solution of the velocity field through Computational Fluid Dynamics (CFD), evaluation of air flow regions, a model for the induced air flow and the mapping of particle dimensions capable to be transport by the fluid medium. The results demonstrate that if the stacking has a drop height greater than the critical one, the boundary layer acceleration at the core-fluid interface gives rise to a pressure gradient leading to the formation of a toroidal vortex near the impact zone, follow by expansion and detachment of the dust boundary layer. The velocity field undergoes a meaningful change and develops ascending updrafts and preferential escape paths for the microparticles. The probability of the process generating dust depends fundamentally on the physical dimensions of the stacking, as well as the type and granulometry of the material whose collisions between the grains generates nanoparticles that remain suspended in the surrounding air, altering the nearby environment and the dust’s ability to diffuse.
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Empilhamento , Material a granel , Camada limite , Vórtice , Poeira