Estimação de Parâmetros de Secagem de Alimentos- Formulação de Luikov e uso da Transformada Integral Generalizada

• Autor(a) principal: Silva, Cristiane Kelly Ferreira da
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/tede/5414
• topic: Secagem de alimentos; Lei de Fick; Luikov; Método inverso; Food drying; Fick law; Luikov; Inverse method; ENGENHARIAS::ENGENHARIA MECANICA

Drying is one of the most widely used commercial processes for the preservation of agricultural products, whose maximum objective is to maintain its qualities. On the other hand, for the optimal design and control of processes and equipments it is necessary a clear understanding of the involved phenomena and the transport properties of the product being handled. In this sense two mathematical models were developed, in the configuration of an infinite plane plate, with the aim of studying the process of drying food. The first model was based on Fick's second law, to model the process of mass transfer, treated by the Classical Integral Transform Technique (CITT). The second model was developed for the analysis of the simultaneous heat and mass transfer using the equations of Luikov, where the distributions of temperature and moisture content inside the food were obtained following the formalism inherent to the Generalized Integral Transform Technique (GITT). In both models, the thermophysical properties are considered constant. The results obtained in the two models were compared and found that they are able to describe the process of drying food. The influence of thermophysical parameters relating to the simultaneous heat and mass transfer was also analyzed. The accuracy of the calculations of a heat and mass balance depends on the precision as that is known the properties of the product and the choice of reliable data for these properties is an important part to any careful analysis engineering. Thus, an inverse problem of parameters estimation, for the mass transfer, was solved through the Levenberg-Marquardt's minimization algorithm. The results obtained through the solution of the inverse problem for the effective mass diffusivity are the same order magnitude of those reported in the literature. Key words - food drying, Fick law, Luikov, GITT, inverse method.