Crystallization and refluidization in very-narrow ... - BV FAPESP
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Crystallization and refluidization in very-narrow fluidized beds

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Autor(es):
Oliveira, Vinicius P. S. ; Borges, Danilo S. ; Franklin, Erick M.
Número total de Autores: 3
Tipo de documento: Artigo Científico
Fonte: Physics of Fluids; v. 35, n. 9, p. 9-pg., 2023-09-01.
Resumo

Fluidization of solid particles by an ascending fluid is frequent in industry because of the high rates of mass and heat transfers achieved. However, in some cases, blockages occur and hinder the correct functioning of the fluidized bed. In this paper, we investigate the crystallization (defluidization) and refluidization that take place in very-narrow solid-liquid fluidized beds under steady flow conditions. For that, we carried out experiments where either monodisperse or bidisperse beds were immersed in water flows whose velocities were above those necessary for fluidization, and the ratio between the tube and grain diameters was smaller than 6. For monodisperse beds consisting of regular spheres, we observed that crystallization and refluidization alternate successively along time, which we quantify in terms of macroscopic structures and agitation of individual grains. We found the characteristic times for crystallization and propose a new macroscopic parameter quantifying the degree of bed agitation. The bidisperse beds consisted of less regular spheres placed on the bottom of a layer of regular spheres (the latter was identical to the monodisperse beds tested). We measured the changes that macroscopic structures and agitation of grains undergo and show that the higher agitation in the bottom-layer hinders crystallization of the top layer. Our results bring new insights into the dynamics of very-narrow beds, in addition to proposing a way of mitigating defluidization. (AU)

Processo FAPESP: 18/14981-7 - Modelagem de escoamentos granulares densos: experimentos, simulações numéricas e análises de estabilidade
Beneficiário:Erick de Moraes Franklin
Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores - Fase 2
Processo FAPESP: 22/01758-3 - Escoamento turbulento em meio granular denso: alterações na estrutura do escoamento
Beneficiário:Danilo da Silva Borges
Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 20/00221-0 - Leitos fluidizados sólido-líquido: escoamento do fluido, dinâmica dos grãos e formação de padrões
Beneficiário:Vinícius Pereira da Silva Oliveira
Modalidade de apoio: Bolsas no Brasil - Doutorado Direto