Abstract:
Fourier's second law was solved using convective boundary conditions without considering the shrinkage of the solid. The solutions for a finite and an infinite slab were compared to determine the dimensions for a slab to be considered as infinite. The solutions obtained for Bi = 0.1 and Bi = 100 correspond to heat and mass transfer-controlled processes, respectively, during drying. The results show that the finite slab cannot be considered as infinite, even for R2/R1 > 20. The relative error obtained when the finite slab was assumed to be infinite was not significant for small Fourier numbers, but it increased as the Fourier number increased; errors were also higher for higher Biot numbers. When the numerical solution of a drying model was obtained for finite and infinite slabs, significant differences in drying kinetics and temperature evolution were observed. Fourier's second law was solved using convective boundary conditions without considering the shrinkage of the solid. The solutions for a finite and an infinite slab were compared to determine the dimensions for a slab to be considered as infinite. The solutions obtained for Bi = 0.1 and Bi = 100 correspond to heat and mass transfer-controlled processes, respectively, during drying. The results show that the finite slab cannot be considered as infinite, even for R2/R1 > 20. The relative error obtained when the finite slab was assumed to be infinite was not significant for small Fourier numbers, but it increased as the Fourier number increased; errors were also higher for higher Biot numbers. When the numerical solution of a drying model was obtained for finite and infinite slabs, significant differences in drying kinetics and temperature evolution were observed.
Registro:
Documento: |
Artículo
|
Título: | Drying of solids: The infinite slab condition |
Autor: | Rovedo, C.O.; Viollaz, P.E. |
Ciudad: | New York |
Filiación: | Biological and Agricultural Eng. Dep, University of California, Davis, CA, United States Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
|
Palabras clave: | Drying; Infinite slab; Unsteady heat conduction; Boundary conditions; Errors; Heat conduction; Heat transfer; Mass transfer; Reaction kinetics; Shrinkage; Solids; Temperature; Biot numbers; Fourier numbers; Fourier second law; Infinite slab condition; Unsteady heat conduction; Drying; Drying; liquid-solid separation |
Año: | 2000
|
Volumen: | 18
|
Número: | 4-5
|
Página de inicio: | 1007
|
Página de fin: | 1021
|
DOI: |
http://dx.doi.org/10.1080/07373930008917750 |
Título revista: | Drying Technology
|
Título revista abreviado: | Dry. Technol.
|
ISSN: | 07373937
|
CODEN: | DRTED
|
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07373937_v18_n4-5_p1007_Rovedo |
Referencias:
- Aguerre, R.J., Suarez, C., Viollaz, P.E., Calculation of the variation of the heat of desorption with moisture content on the basis of BET theory (1984) J. Food Technology, 19, pp. 325-331
- Aguerre, R.J., Suarez, C., Viollaz, P.E., Enthalpy-entropy compensation in sorption phenomena: Application to the prediction of the effect of temperature on food isotherms (1986) J. Food Science, 51, pp. 1547-1549
- Heldman, D.R., Lund, D.B., (1992) Handbook of Food Engineering, , (ed. Marcel Dekker, New York)
- Lin, S.H., Moisture desorption in cellulosic materials, Ind (1991) Engineering Chem. Res., 30, pp. 1833-1836
- Lopez, A., Pique, M.T., Boatella, J., Ferran, A., Garcia, A., Romero, J., (1998) Drying Characteristics of the Hazelnut, Drying Technology, 16, pp. 627-649
- Luikov, A.V., (1968) Analytical Heat Diffusion Theory, , Hartnett, J.P. Editor, Academic Press, New York
- Martinez-Vera, C., Vizcarra-Mendoza, M., Galan-Domingo, O., Ruizmartinez, R., Experimental validation of a mathematical model for the batch drying of corn grain (1995) Drying Technology, 13 (1-2), pp. 333-350
- Prausnitz, J.M., Eckert, C.A., Orye, R.V., O'Connell, J.P., (1967) Computer Calculation for Multicomponent Vapor Liquid Equilibrium., p. 219. , Englewood Cliffs NJ. Prentice-Hall
- Rovedo, C.O., (1994) Transferencia Simultânea De Calor Y Materia En Sistemas Con Cambio De Volumen: Aplicaciön Al Secado De Plaças De Papa., , PhD Dissertation. University of Buenos Aires, Argentina
- Rovedo, C.O., Viollaz, P.E., Suarez, C., Drying simulation of a solid slab with three dimensional shrinkage (1995) Drying Technology, 13 (1-2), p. 371393
- Treybal, R.E., (1980) Operaciones De Transferencia De Masa (2da. Edition), , McGraw-Hill Book Co
- Vaccarezza, L.M., Lombardi, J.L., Chirife, J., Kinetics of moisture movement during air drying of sugar beet root, J (1974) Food Technology, 9, pp. 3IT-327
- Vagenas, G.K., Drouzas, A.E., Marinos-Kouris, D., Saravacos, G.D., Predictive equations for thermophysical properties of plant foods (1990) In: Engineering and Food, Vol.1. Physical Properties and Process Control. London and New York. Elsevier Applied Science., pp. 399-407
Citas:
---------- APA ----------
Rovedo, C.O. & Viollaz, P.E.
(2000)
. Drying of solids: The infinite slab condition. Drying Technology, 18(4-5), 1007-1021.
http://dx.doi.org/10.1080/07373930008917750---------- CHICAGO ----------
Rovedo, C.O., Viollaz, P.E.
"Drying of solids: The infinite slab condition"
. Drying Technology 18, no. 4-5
(2000) : 1007-1021.
http://dx.doi.org/10.1080/07373930008917750---------- MLA ----------
Rovedo, C.O., Viollaz, P.E.
"Drying of solids: The infinite slab condition"
. Drying Technology, vol. 18, no. 4-5, 2000, pp. 1007-1021.
http://dx.doi.org/10.1080/07373930008917750---------- VANCOUVER ----------
Rovedo, C.O., Viollaz, P.E. Drying of solids: The infinite slab condition. Dry. Technol. 2000;18(4-5):1007-1021.
http://dx.doi.org/10.1080/07373930008917750