Mathematical Problems in Engineering
Volume 2012 (2012), Article ID 386214, 18 pages
Research Article

Thin-Layer Drying Characteristics and Modeling of Chinese Jujubes

1College of Biological and Agricultural Engineering, Jilin University, Changchun 130022, China
2College of Mechanical and Electronic Engineering, Tarim University, Alar 843300, China
3Institute of Grain Machinery Research, Jilin Academy of Agricultural Machinery, Changchun 130022, China

Received 8 December 2011; Accepted 31 January 2012

Academic Editor: Zhijun Zhang

Copyright © 2012 Xiao-Kang Yi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A mathematical modeling of thin-layer drying of jujubes in a convective dryer was established under controlled conditions of temperature and velocity. The drying process took place both in the accelerating rate and falling rate period. We observed that higher temperature reduced the drying time, indicating higher drying rates of jujubes. The experimental drying data of jujubes were used to fit ten different thin-layer models, then drying rate constants and coefficients of models tested were determined by nonlinear regression analysis using the Statistical Computer Program. As for all the drying models, the Weibull distribution model was superior and best predicted the experimental values. Therefore, this model can be used to facilitate dryer design and promote efficient dryer operation by simulation and optimization of the drying processes. The volumetric shrinkable coefficient of jujubes decreased as the drying air temperature increased.