快速干燥过程中多孔介质内部湿分迁移机理的研究

INVESTIGATION ON MOISTURE TRANSFER MECHANISM IN POROUS MEDIA DURING RAPID DRYING PROCESS

本文对快速干燥过程中多孔介质内部湿分迁移机制进行了实验研究和理论分析。实验本体是一台Ｘ－６５０扫描电子显微镜；实验样品分别为大蒜；胡萝卜和土豆片。提出了压力梯度作用下的毛细管通道内的挤压流动是高强度干燥过程中湿分迁移的主要机理并对单毛细管通道内的挤压流动进行了理论分析。

In this work, moisture transfer mechanism in wet porous media during rapid drying process was investigated experimentally and analytically. By use of scanning electron microscopic device, the rapid drying processes for potato, carrot and radish species were observed and recorded. A new displacement mechanism by pressure gradient in porous material during rapid drying was suggested. To analyze this displacement flow in porous material, a single capillary tube model was set up. The velocity of the displacement flow and its flow rate as well as displacement time of moisture were calculated.