Applying Liquid Diffusion Model for Continuous Drying of Rough Rice in Fixed Bed

Abstract

Simulate the rice drying process at specific drying conditions is of great interest to optimize the process and ensure a better quality of the final product. In the present work, experimental drying procedures of rough rice grains (BRSMG CONAI variety) was reported and drying kinetic was obtained at temperature using 40°C. The results were compared with simulated data by means of the liquid diffusion model equilibrium boundary condition. The geometry used to represent the rice grain was prolate spheroid. For this purpose, the diffusion equation, written in cylindrical coordinates, and solved via Galerkin-based integral method considering the constant diffusion coefficient. A good agreement was observed between predicted and experimental data. It was also possible to observe that the highest moisture gradients occur at the tip of the grain, which is region more affected by thermal and hydric stresses. The studied model can be used to solve problems involving diffusion processes, such as: drying, wetting, heating and cooling, provided that the geometrical shape of the body is similar to prolate spheroid.

Modelagem Matemática e Simulação Computacional da Secagem Contínua e Intermitente de Sólidos Elipsoidais

“…onde d nj são constantes a serem determinadas e as N funções de base são escolhidas em um conjunto completo f j (r, z), j = 1, 2, 3, • • • de funções linearmente independentes, f j definidas em Ω, satisfazendo a condição de contorno homogênea (3). Para a geometria elipsoidal, as funções de base que satisfazem a condição de contorno de Dirichlet homogênea são dadas em [4] da seguinte forma:…”

“…Poucos são os 2 trabalhos científicos que utilizam a geometria elipsoidal e cujo objetivo principal seja a otimização do processo de secagem intermitente [7,9]. Dentre os métodos reportados na literatura para obter solução de equações diferenciais parciais, o método integral baseado em Galerkin (método GBI) tem sido usado para obter solução analítica aproximada da equação de difusão para geometrias arbitrárias [2,3,8,10]. Em [2] os autores usaram o método GBI para simular secagem intermitente de grãos de arroz em casca, negligenciando o período de têmpera.…”

“…Em [2] os autores usaram o método GBI para simular secagem intermitente de grãos de arroz em casca, negligenciando o período de têmpera. Em [3] o modelo de difusão foi aplicado para descrever secagem contínua de grãos de arroz em casca em leito fixo. Para tanto, o grão de arroz foi representado por um elipsoide prolato e a equação de difusão foi resolvida via método GBI, com condição de contorno de Dirichlet.…”

Laminar fluid flow in concentric annular ducts of non-conventional cross-section applying GBI method

“…The Galerkin-based integral (GBI) method has well-known applicability in flow analysis in straight ducts with arbitrary geometry (Lee & Kuo, 1998;Lee & Lee, 2001;dos Santos Júnior et al, 2020;Santos Júnior, 2018;Haji-Sheikh & Beck, 1990;Lakshminarayanan & Haji-Sheik, 1992). However, it can also be used in other engineering areas (Franco et al, 2016;Pessôa et al, 2017;Santos et al, 2015;Santos et al, 2012;Lima et al, 2004;Franco et al, 2019;Lima et al, 2014). Dos Santos Júnior et al (2020), present a theoretical study applied to fully developed internal laminar flow through a corrugated cylindrical duct, using the Galerkin-based integral method.…”

Heavy Oil Laminar Flow in Corrugated Ducts: A Numerical Study Using the Galerkin-Based Integral Method

“…Further, the Galerkin-based integral method has been successfully applied in algorithms in the fields of differential equations [12][13][14], analysis [15], mechanics, thermodynamics and hydrodynamics [16][17][18][19], and also in other engineering fields [20,21]. Specifically, in the calculation of the temperature and/or velocity in ducts, we can cite works with circular, rectangular, isosceles triangular, right triangular, and annuli cross-sections [22][23][24].…”