Numerical investigation of particle segregation in polydisperse fluidized beds

• Grant number: 22/08321-0
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2022
• Effective date (End): July 14, 2024
• Field of knowledge: Engineering - Mechanical Engineering - Transport Phenomena
• Principal Investigator: Erick de Moraes Franklin
• Grantee: Henrique Barbosa de Oliveira
• Host Institution: Faculdade de Engenharia Mecânica (FEM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 18/14981-7 - Modeling of dense granular flows: experiments, numerical simulations and stability analyses, AP.JP2

Abstract

Fluidized beds consist of suspensions of granular matter by an ascending fluid flow in a vertical tube. Devices using fluidized beds are commonly employed in industry, given their high rates of heat and mass transfers. Some examples are the combustion of coal and coating of solids. They are also used for particle classification and separation, such as happens in water treatment, and chemical and mining processes. Uniform fluidized beds are rarely encountered in industrial applications and instabilities, such as transverse waves, bubbles and long bubbles, usually appear. In most cases, fluidized beds consist of more than one species of particles, differing in size, density and shape. In those cases, grains segregate and form stratified layers with only one species each, and, if the fluid is a liquid, the layer inversion phenomenon, where layers invert their relative position, can happen. Therefore, understanding how grains segregate and the conditions for layer inversion is important for industrial processes involving polydisperse granular material. This MSc. Thesis will investigate numerically the segregation in solid-liquid fluidized beds by using CFD-DEM (computational fluid dynamics - discrete element method). We aim at obtaining trajectories of individual grains and momentum transfers by grain-grain and grain-wall shocks, which are fundamental data lacking in the literature. In addition, we intend to propose analytical expressions for segregation thresholds.