Diffusive model with variable effective diffusivity considering shrinkage in thin layer drying of chitosan

被引:54
作者
Batista, Lucia M. [1 ]
da Rosa, Cezar A. [1 ]
Pinto, Luiz A. A. [1 ]
机构
[1] Univ Fed Rio Grande do Sul, Dept Chem, Fundacao, BR-96201900 Rio Grande, RS, Brazil
关键词
chitosan; shrinkage; diffusive model; drying; MOISTURE DIFFUSION;
D O I
10.1016/j.jfoodeng.2006.10.014
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
In the thin layer drying of chitosan, a diffusive model considering the material volume change was used, due to the occurrence of shrinkage during the operation. The samples were placed in a rectangular tray with 4 mm of thickness, and inserted in the discontinuous dryer, with parallel air flow at 60 degrees C of temperature and air speed of 1.5 m/s. The sample shrinkage occurred in the thickness, and the linear shrinkage coefficient was constant. In the model, variable moisture effective diffusivity and equilibrium conditions at the material surface were considered. The dimensionless second order non linear partial differential equation, resulting from the model, was solved numerically by the finite differences technique. A good agreement between the numerical data of the average moisture content, obtained by the model. and the experimental data was observed. (c) 2006 Elsevier Ltd. All rights reserved.
引用
收藏
页码:127 / 132
页数:6
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