颗粒表面料层干燥机理

Drying mechanism of thin film coated on particle surface

颗粒表面料层干燥是喷雾流化干燥技术的基本环节 .为了探讨喷雾流化干燥机理 ,着重探讨了物料表面蒸汽分压与物料湿含量的关系 ,首次建立了单颗粒表面料层干燥的物理模型 ,并进行了数值计算 ,计算结果与实验结果吻合较好 .分析了惰性载体的密度、比热容、直径及热导率对干燥时间的影响 ,对喷雾流化干燥的深入研究以及放大、优化设计等具有重要的指导意义 .

Drying of the thin film coated on a particle surface is a basic step for spray-fluidized-bed drying. In this work, the relationship between the vapor pressure and the moisture content of the wet materials is analyzed and a physical model for the drying of the thin film coated on a particle surface is proposed to study the mechanism of spray-fluidized-bed drying. The numerical simulation is in good agreement with the experimental data. In addition, the effects of some particle parameters, such as density, specific heat, diameter, thermal conductivity, on the drying are discussed. The results can be used for the scale-up and optimal design of spray-fluidized-bed drier.