Artículos de revistas
Theoretical Study Of Intermittent Drying (tempering) In Prolate Spheroidal Bodies
Registro en:
Drying Technology. , v. 19, n. 8, p. 1569 - 1589, 2001.
7373937
10.1081/DRT-100107260
2-s2.0-0035164752
Autor
De Lima A.G.B.
Nebra S.A.
Institución
Resumen
The process of intermittent drying in prolate spheroidal bodies was simulated assuming liquid diffusion to be the sole mass transport process, a constant diffusion coefficient and equilibrium conditions at the surface. The mass diffusion equation in a prolate spheroidal coordinate system was used for a two-dimensional case. Due to the use of a dimensionless coordinate system, a Fourier number for tempering is defined, in order to determine the dimensionless time required to achieve a flat moisture content profile. Assuming that the drying process is stopped only once at a fixed point, the tempering Fourier number was determined for aspect ratios of 1.1, 2.0 and 5.0. Many cases were studied, changing the tempering Fourier and aspect ratio of the body. Focusing on the drying rate, the effect of one, two and four drying passes was studied for different interruption points in the process and aspect ratios of 1.1, 2.0 and 5.0, in all cases using the continuous process as a comparison. From the numerical results it was found that during the tempering process, the drying rate and the final mean moisture content are affected by the tempering Fourier number, multipass drying and geometrical dimensions of the body. 19 8 1569 1589 Brooker, D.B., Bakker-Arkema, F.W., Hall, C.W., (1978) Drying Cereal Grains, , AVI Publishing Company, Inc., Connecticut, 265 p Elbert, G., Tolaba, M.P., Surez, C., Effects of drying and tempering on head parboiled rice yield (1997) IADC - Inter-American Drying Conference, B, pp. 502-507. , Itu, Brazil Fioreze, R., (1986) The Intermittent Drying Agricultural Crops With Particular Reference to Energy Requirements, , Ph.D. Thesis. Granfield Institute of Technology, Silsoe College, 153 p Franca, A.S., Fortes, M., Haghighi, K., Numerical simulation of intermittent and continuous deep-bed drying of biological materials (1994) Drying Technology, 12 (7), pp. 1537-1560 Hall, C.W., (1980) Drying, and Storage of Agricultural Crops, , AVI Publishing Company, Inc., Connecticut, 381 p Lima, A.G.B., Nebra, S.A., Altemani, C.A.C., Simulation of the drying kinetics of the silkworm cocoon considering diffusive mechanism in elliptical coordinate (1997) IADC - Proceedings of the Inter-American Drying Conference, B, pp. 317-324. , Itu, Brazil Lima, A.G.B., Diffusion phenomenon in prolate spheroidal solids (1999) Case Studies: Drying of Banana, , Doctor Thesis, State University of Campinas, Campinas, Brazil, 265p., (In portuguese) Lima, A.G.B., Nebra, S.A., Theoretical analysis of the diffusion process inside prolate spheroidal solids (2000) Drying Technology, 18 (1-2), pp. 21-48 Maliska, C.R., (1995) Computational Heat Transfer and Fluid Mechanics, , LTC, Rio de Janeiro, 424 p., (In portuguese) Pakowski, Z., Mujumdar, A.S., (1987) Handbook of Industrial Drying. Chapter 3: Basic Process Calculations in Drying, pp. 83-129. , Marcel Dekker, Inc Patankar, S.V., (1980) Numerical Heat Transfer and Fluid Flow, , Hemisphere Publishing Corporation, New York, 197 p Sabbah, M.A., Foster, G.H., Haugh, C.G., Peart, R.M., Effect of tempering after drying on cooling shelled corn Transaction of the ASAE, 15 (4), pp. 763-765 Singh, R.P., Wang, C.Y., Zuritz, C., A numerical approach to simulate rice drying (1980) Proceeding of the Second International Drying Symposium (IDS'80), 1, pp. 227-232. , Montreal Steffe, J.F., Singh, R.P., Theoretical and practical aspects of rough rice tempering (1980) Transaction of the ASAE, pp. 775-782 Steffe, J.F., Singh, R.P., Bakshi, A.S., Influence of tempering time and cooling on rice milling yields and moisture removal (1979) Transactions of the ASAE, 22, pp. 1214-1218. , and 1224 Strumillo, C., Kudra, T., (1986) Drying: Principles, Science and Design, , Gordon and Breach Science Publishers, New York, 448 p Tolaba, M.P., Aguerre, R.J., Suárez, C., Drying of corn with tempering: Simulation and experimental verification (1997) IADC - Inter-American Drying Conference, B, pp. 516-523. , Itu Walker, L.P., Bakker-Arkema, F.W., Energy efficiency in concurrent rice drying (1981) Transactions of the ASAE, 24, pp. 1352-1356 Zhang, D., Mujumdar, A.S., Deformation and stress analysis of porous capillary bodies during intermittent volumetric thermal drying (1992) Drying Technology, 10 (2), pp. 421-443 Zhang, Q., Litchfield, J.B., An optimization of intermittent corn drying in a laboratory scale thin layer dryer (1991) Drying Technology, 9 (2), pp. 383-395