化工学报 ›› 2004, Vol. 55 ›› Issue (6): 869-875.

• 传递现象 • 上一篇    下一篇

具有电介质核圆柱多孔介质微波冷冻干燥过程的双升华界面模型

吴宏伟; 陶智;陈国华;邓宏武;徐国强;丁水汀   

  1. 北京航空航天大学能源与动力工程学院,北京 100083;香港科技大学化学工程系,香港 九龙
  • 出版日期:2004-06-25 发布日期:2004-06-25

DOUBLE SUBLIMATION FRONTS MODEL WITHIN CYLINDRICAL POROUS MEDIA WITH CYLINDRICAL DIELECTRIC CORES IN MICROWAVE FREEZE DRYING

WU Hongwei;TAO Zhi;CHEN Guohua;DENG Hongwu;XU Guoqiang;DING Shuiting   

  • Online:2004-06-25 Published:2004-06-25

摘要: 建立了具有电介质核多孔介质微波冷冻干燥过程的耦合传热传质的数学模型,应用变时间步长的有限体积法对各控制方程进行数值求解.计算结果表明:(1)多孔介质内部存在着两个升华界面;(2)同无核相比,合理选用电介质核可大大缩短干燥时间;(3)在初始饱和度较低时(S0=0.2),有、无电介质核两种情况下所需干燥时间相差较大,仍可在物料中加入电介质核来加速干燥.

关键词: 冷冻干燥, 多孔介质, 微波加热, 电介质核柱, 双升华界面

Abstract: A mathematical model of double sublimation fronts was developed for microwave freeze-drying for a cylindrical porous media with cylindrical dielectric cores.The set of transient governing equations describing the drying process were solved numerically with the variable time-step finite volume method.The numerical results showed that two sublimation fronts did exist within the porous media.Proper usage of cylindrical dielectric cores could dramatically reduce the drying time.The impact of cylindrical dielectric cores on drying could not be ignored even though the initial saturation was low(S0=0.2).

Key words: 冷冻干燥, 多孔介质, 微波加热, 电介质核柱, 双升华界面