Mathematical Problems in Engineering
Volume 2012 (2012), Article ID 941609, 16 pages
Research Article

Model of Mass and Heat Transfer during Vacuum Freeze-Drying for Cornea

1School of Municipal and Environment Engineering, Shenyang Jianzhu University, Shenyang 110168, China
2Management School, Shenyang Jianzhu University, Shenyang 110168, China
3School of Chemical Engineering Equipment, Shenyang University of Technology, Liaoyang 111003, China

Received 22 March 2012; Accepted 3 May 2012

Academic Editor: Zhijun Zhang

Copyright © 2012 Zou Huifen 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.


Cornea is the important apparatus of organism, which has complex cell structure. Heat and mass transfer and thermal parameters during vacuum freeze-drying of keeping corneal activity are studied. The freeze-drying cornea experiments were operated in the homemade vacuum freeze dryer. Pressure of the freeze-drying box was about 50 Pa and temperature was about −10°C by controlled, and operating like this could guarantee survival ratio of the corneal endothelium over the grafting normal. Theory analyzing of corneal freeze-drying, mathematical model of describing heat and mass transfer during vacuum freeze-drying of cornea was established. The analogy computation for the freeze-drying of cornea was made by using finite-element computational software. When pressure of the freeze-drying box was about 50 Pa and temperature was about −10°C, time of double-side drying was 170 min. In this paper, a moving-grid finite-element method was used. The sublimation interface was tracked continuously. The finite-element mesh is moved continuously such that the interface position always coincides with an element node. Computational precision was guaranteed. The computational results were agreed with the experimental results. It proved that the mathematical model was reasonable. The finite-element software is adapted for calculating the heat and mass transfer of corneal freeze-drying.