The principle of vacuum coating machine vacuum drying equipment and process

The principle of vacuum coating machine vacuum drying equipment and process

Vacuum coating machine equipment vacuum drying process includes three processes. By the heat source to heat transfer to the material, make its heat and moisture vaporization, known as the heat transfer process. "Evaporation of moisture vapor migration to the drying room space, make the moisture vapor from the material surface and discharge drying chamber, the so-called material surface moisture vapor state mass transfer process.
Material internal moisture migration with liquid to the material surface, so that the surface evaporation, the so-called material internal moisture liquid mass transfer process. Visible, vacuum drying is accompanied by the three process and coordination, the coordination of good or bad, directly affect the quality of vacuum drying speed and its products.
Complete the heat and mass transfer process, the following three requirements must be met. Depending on the implementation of the heat transfer temperature difference between the heat source and material, provide materials with heating of the heat and moisture latent heat of vaporization, the so-called temperature condition. "Depend on the material surface and the moisture vapor pressure of drying chamber space to implement material moisture gas mass transfer, the so-called pressure (or vacuum) conditions, therefore must ensure that the moisture in the material on the surface of the steam pressure is higher than steam steam partial pressure of drying chamber space.
Depend on the material internal moisture moisture inside the material with the concentration of the liquid mass transfer, the so-called concentration condition. Optimization of the above three conditions and their combination can improve the quality of vacuum drying speed and its products.