Simulação do recobrimento de partículas em leito de jorro usando modelos de balanço populacional

by Oliveira Silva, Danylo de

Abstract (Summary)
A dynamic simplified model based on population balances is used to calculate the populationdensity function of a particles coating process in a spouted bed with a draft tube, considering anindependent size growing. The model considers the bed composed by two constant size domainsof perfect mixture, where occurs coating and drying of particles, with circulation among them.The model is made dimensionless, so that the independent variable related to the coating mass isequal to the dimensionless residence time in the coating domain. This way, the distributionfunctions can be treated as residence time distributions, defined for each domain. The model isformed by hyperbolic partial differential equations, being analytically solved by Laplacetransform and Moments Method. The model parameters that define the coating and dryingdomains, the porosity profile at the fountain and the particles circulation rate are obtained throughgeometric relationships and CFD simulations. The experimental frequency distribution curvesrelated to the soybean seeds coating with inoculant and micronutrients, for different operationalconditions and at the final operation time were compared with the simulated ones by the model,showing a good agreement. The values of moments, averages and standard deviations,analytically calculated, are presented for the several simulated cases, allowing the evaluation ofthe coating uniformity. The representation by normal distributions was not appropriated at thesimulated conditions. The effects of the coating suspension flow rate and of the coating domainsize over the distributions are analyzed, allowing the identification of operational conditionswhich make possible larger coating uniformity.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Adilson José de Assis; Marcos Antonio de Souza Barrozo; Valeria Viana Murata; Luís Cláudio Oliveira Lopes; Ana Maria da Silveira

School:Universidade Federal de Uberlândia

School Location:Brazil

Source Type:Master's Thesis

Keywords:Spouted bed Coating Population balance Soybean Perfect mixture model


Date of Publication:03/30/2006

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