被干燥多孔物料中孔隙大小及分布的探讨

从多孔物料的微观结构出发,利用平衡湿含量的实验数据,对三十多种多孔建筑物料的孔隙分布规律进行了分析,结果表明其分布服从对数正态分布.得出了降速干燥阶段多孔物料孔隙中水液面蒸气相对分压与湿含量的关系式,计算值与实验值具有较好的一致性,均方根误差为3.01%.还分析了降速干燥阶段多孔物料中孔隙分布参数、温度、湿含量对其中水液面蒸气相对分压的影响.

A Study on the Void Distribution of Porous Materials Being Dried

Basing on the analysis of micro-structure and the experimental data of equilibrium moisture content of the porous construction materials, this paper studies the relationship between the equilibrium moisture content and the void distribution of porous materials.The results show that the void distribution obeys log arithmic normal function.According to this, the relation between the vapor pressure P(r)/P_H and the moisture content of the porous materials in the falling rate drying period is obtained.The calculation result approximately agrees with the experimental data with only 3.01% root mean square error.In addition, the effects of the void distribution parameters μ, σ, the temperature and the moisture content on the vapor pressure P(r)/P_H of the porous materials in the falling rate drying period are analyzed.The results can be used to study the heat and mass transfer of porous materials during the falling rate drying period.