微波加热干燥毛细多孔介质的传热传质机理分析  

ANALYSIS OF HEAT AND MASS TRANSFER CHARACTERISTICS IN DRYING PROCESS OF POROUS MEDIUMS BY MICROWAVE

作　　者：郑镇[1] 孟霞 

机构地区：[1]华北电力学院 [2]南京水泥工业设计研究院

出　　处：《华北电力学院学报》1991年第1期51-58,共8页

摘　　要：本文在实验基础上系统分析了微波加热干燥湿物料的理论机理。提出了微波加热干燥毛细多孔湿物料是由初始加热阶段,压力泵水、泵汽(包括压力产生过程,压力泵汽水混合物主过程和压力驱动较难干燥水分蒸汽过程)阶段,干燥难干水分阶段组成。并结合反映每一阶段的主要特点建立了其特征物理模型。这些研究,比较全面的、抽象概括了微波加热干燥湿毛细多孔物料整个过程的物理特征。并初步分析了微波干燥过程驱动湿分的主动力——压力在无限长圆柱体内的分布规律。进而在分析的基础上提出了采用集总湿容法建立反映干燥规律较实用的物理模型。并根据电磁能吸收的特点,将干燥过程分为两段建立模型。这组模型能够比较好地反映实验规律。A theoretical analysis of drying process of porous mediums by microwave is carried out, the drying process of moist porous substances consists of three phases or five phases in detail; the physical model for each phase is built to describe the drying characteristics of moist materials. Presssure gradient is found to be the major driving force for the migration of moisture. Pressure distribution in an infinitely long cylinder is given. Mass concentration gradient is very small under the microwave drying. Thus, the 'lumped moisture capacity method' is used to set up physical models for the microwave drying process.According to the characteristics of absorption of eletromagnetic energy, the drying process can be divided into two phases to set up models, which conform to the experimental results rather satisfactorily.

关 键 词：微波加热 干燥 传热 物理模型 

分 类 号：TK124[动力工程及工程热物理—工程热物理]