Spray dryerThe heat and mass transfer model of biological material needs to know the material density, specific heat capacity, thermal conductivity and other thermophysical properties. The thermal properties of the data acquisition is determined based optimal drying of biological materials, the thermal properties of biological materials is more complex, not only related to water content, composition, temperature, and material structure, combined with water and the components of the composition, structure, and the drying process is constantly changing and the foundation of accurate need to do in-depth and meticulous work estimation method, when the known material components and thermal properties of components, can give biological materials, three basic thermal properties (density, specific heat capacity, thermal conductivity) estimation method, as the practical application and reference.