A novel mechanism for bubble formation in fluidized systems: the effects of granular temperature on the stability in fluidization



Título del documento: A novel mechanism for bubble formation in fluidized systems: the effects of granular temperature on the stability in fluidization
Revista: Brazilian journal of chemical engineering
Base de datos: PERIÓDICA
Número de sistema: 000308950
ISSN: 0104-6632
Autors: 1
Institucions: 1Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Campinas, Sao Paulo. Brasil
Any:
Període: Sep
Volum: 21
Número: 3
Paginació: 479-486
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental, aplicado
Resumen en inglés This work contains a novel approach for the study of stability in fluidized systems. It includes the influence of solid particle kinetic energy variations, which are known as granular temperature. The stability is verified by the temporal evolution of bed fluid-dynamics properties (solid volumetric fraction, fluid velocity, solid particles velocity) after small perturbations. The bed is stable when the amplitudes of perturbations decrease with time. The work departs from the mass and momentum continuity equations for the solid and fluid phase, as proposed by Anderson and Jackson (1968). Those are complemented by an equation describing the energy balance from the point of view of granular temperature. Then, a linear approximation for the equations after the introduction of small magnitude perturbations is obtained. The application of harmonic solutions allows arriving to the temporal description of the perturbations. Results show the occurrence of instabilities on the direction transverse to gravity. This cannot be observed by previous approaches (Anderson and Jackson, 1968, 1969; Homsy et al., 1980; Liu, 1982). The present work also suggests a new mechanism for the formation of bubbles in fluidized systems. The parametric influence of the model on the stability of fluidized systems is also verified
Disciplines Química
Paraules clau: Ingeniería química,
Lecho fluidizado,
Temperatura granular,
Formación de burbujas,
Análisis linear,
Estabilidad
Keyword: Chemistry,
Chemical engineering,
Fluidized bed,
Granular temperature,
Bubble formation,
Linear analysis,
Stability
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