Modeling of water transport in roof tiles by removal of moisture at isothermal conditions

Silva, Wilton Pereira da; Farias, Vera Solange de Oliveira; Neves, G. A.; Lima, Antônio Gilson Barbosa de

doi:10.1007/s00231-011-0931-4

Cited by 48 publications

(41 citation statements)

References 31 publications

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“…However, in this case, a simpler model may be more efficient to describe the drying kinetics. Therefore, it should be pointed out that, according to Silva et al (2012), for such a low Biot number, the infinite series that represents the solution of the diffusion equation can be represented only by its first term, with negligible truncation error. In this case, this first term can be interpreted as the Henderson-Pabis equation, e.g.…”

Section: Description Of Diffusion Modelmentioning

confidence: 99%

“…It should be noted that the highest truncation error of the infinite series given by Equation (2) occurs for t = 0, and this error depends on the Biot number referring to drying (Silva et al, 2012). In order to define the number of terms (nt) to be used in Equation (2), the study of Silva et al (2012) was taken into consideration. These researchers observed that, for Bi = 0.001, only 1 term is necessary to obtain X * (0) = 1.0, which is the expected value.…”

Section: Diffusion Modelmentioning

confidence: 99%

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Production of kiwi snack slice with different thickness: Drying kinetics, sensory and physicochemical analysis

Moreira¹,

Silva²,

Castro³

et al. 2018

Aust J Crop Sci

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In the modern world, light and healthy meals are increasingly consumed between the main meal courses. Therefore, market has made a wide variety of products of this type available, usually without artificial additives. This study aimed to produce snacks through the thin-layer drying of kiwi slices. Circular kiwi slices were cut into various thicknesses (5.0, 10.0 and 15.0 mm) and subject to different drying air temperatures (50, 60, 70 and 80 o C). Drying was described using several mathematical models, both diffusion (boundary condition of the third kind) and empirical (Henderson-Pabis, Lewis, Page, Silva et al.) models. According to diffusion model, kiwi slices showed an almost uniform moisture distribution over time. The Page equation/model showed the best fit to the experimental data, compared to other models. At the end of the drying process (until equilibrium), slices with initial thickness of 5.0 mm had a rigid consistency, suitable for production of flour through grinding. On the other hand, slices with initial thicknesses of 10.0 and 15.0 mm were soft; thus, they can be consumed as snacks. Sensory and physicochemical analyses showed that the product cut with initial thickness of 15.0 mm and dried at temperature of 70 ºC (until moisture content of 0.31 kg water /kg dry matter ) was the tastiest one and showed good results for the analyzed chemical compounds.

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Section: Description Of Diffusion Modelmentioning

confidence: 99%

Section: Diffusion Modelmentioning

confidence: 99%

Production of kiwi snack slice with different thickness: Drying kinetics, sensory and physicochemical analysis

Moreira¹,

Silva²,

Castro³

et al. 2018

Aust J Crop Sci

View full text Add to dashboard Cite

show abstract

“…Moreover, models involving convective boundary condition is better to describe the drying process of tiles, since there is always resistance to mass flow on the surface of the product [19]. Various studies adopt the convective boundary condition for the description of drying processes [3,20,14].…”

Section: Introductionmentioning

confidence: 99%

Drying of clay slabs: prediction by means of one-dimensional diffusion models

Aires

Júnior

Aires

et al. 2015

Mat.-wiss. u. Werkstofftech

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The main purpose of this article is to describe convective drying of clay slabs with initial moisture content of 0.11 (db) at temperatures of 50 and 90°C. To describe the water diffusion process, was considered: a) constant effective mass diffusivity (Model 1); b) variable effective mass diffusivity (Model 2). A numerical solution of the onedimensional diffusion equation with boundary condition of the third kind was proposed in order to describe the drying process. The solution was coupled with an optimizer in order to estimate the process parameters for each drying air temperature using experimental datasets and the inverse method. Comparative studies were performed between Models 1 and 2 in order to define the accuracy of description of the drying process. Comparative studies are also conducted on the proposed models and on diffusive models with two-and three-dimensional geometries. An analysis of statistical indicators shows that Model 2 is comparable to models with twoand three-dimensional geometries, being in perfect agreement with the experimental results. However, the computational processing time for the proposed model is much shorter than that obtained with the use of two-and three-dimensional geometries. However, it was observed that the one-dimensional model overestimates the process parameters.

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“…Several studies have been reported in literature using a diffusion model to describe the physical process, and consider the geometric shape of the bodies as cylinder, sphere, or infinite slab [7][8][9][10][11]. Analytical and numerical solutions to predict heat and mass diffusion in porous bodies are also reported for prolate and oblate spheroids [12,13], as well as parallelepipeds [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Assessment of diffusion models to describe drying of roof tiles using generalized coordinates

Farias

Silva

et al. 2015

Heat Mass Transfer

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This article aims to study the mass transient diffusion in solids with an arbitrary shape, highlighting boundary condition of the third kind. To this end, the numerical formalism to discretize the transient 3D diffusion equation written in generalized coordinates is presented. For the discretization, it was used the finite volume method with a fully implicit formulation. An application to drying of roof tiles has been done. Three models were used to describe the drying process: (1) the volume V and the effective mass diffusivity D are considered constant for the boundary condition of the first kind; (2) V and D are considered constant for the boundary condition of the third kind and (3) V and D are considered variable for the boundary condition of the third kind. For all models, the convective mass transfer coefficient h was considered constant. The analyses of the results obtained make it possible to affirm that the model 3 describes the drying process better than the other models. List of symbols Latin symbols A, BCoefficients of algebraic equation of the discretized equation A 1 , B 1 , C 1 , Constants obtained by non-linear regression for dimensions of the tiles a, bFitting parameters obtained by optimization D efEffective water diffusivity (m 2 s -1 ) E, L, C Dimensions of the roof tiles (m) hConvective mass transfer coefficient (m s -1 ) J Jacobian of the transformation (m -3 )

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Modeling of water transport in roof tiles by removal of moisture at isothermal conditions

Cited by 48 publications

References 31 publications

Production of kiwi snack slice with different thickness: Drying kinetics, sensory and physicochemical analysis

Production of kiwi snack slice with different thickness: Drying kinetics, sensory and physicochemical analysis

Drying of clay slabs: prediction by means of one-dimensional diffusion models

Assessment of diffusion models to describe drying of roof tiles using generalized coordinates

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