Application of vacuum pump in vacuum drying

The vacuum pump has been widely used in the vacuum drying process, the vacuum drying is a kind of material will be placed under the negative pressure condition, and through the appropriate heating to dry to dry materials through melting point boiling point under negative pressure or by cooling the material after solidification. The material moisture inside the melting point under the condition of negative pressure boiling point decreased with the increase of vacuum, supplemented by vacuum pump pumping water vapor wet gap is reduced, the material water solution to obtain enough kinetic energy from the surface of the material. Vacuum drying due to maintain the original characteristics in the state of negative pressure air makes part of easily oxidized chemical changes in the drying process of the material better, also can better protect the material by injecting inert gas after vacuum mode. Common vacuum drying equipment: vacuum drying box, continuous vacuum drying equipment, etc..

The process of vacuum drying is the drying material placed in the drying chamber sealed, vacuum system for vacuum pumping and the materials to be dried continuously heating, so that the material inside the water by pressure difference or differential concentration diffusion to the surface, the water molecules to obtain enough kinetic energy in the material surface, to overcome the mutual attraction between molecules, low pressure space escape into the vacuum chamber, the vacuum pump to go. In the vacuum drying process, the pressure in the drying chamber is always lower than the atmospheric pressure, the number of gas molecules is small, the density is low, the oxygen content is low, so it can dry the material which is easy to oxidative deterioration, flammable and explosive dangerous goods, etc.. Drugs, food and biological products can play a certain role in disinfection and sterilization, can reduce the chance of bacterial infection or inhibit the growth of certain bacteria.

Because the temperature of the water is proportional to the vapor pressure in the vaporization process, the water in the material can be vaporized at low temperature during vacuum drying, and the drying can be realized at low temperature. This is advantageous for some drugs, heat sensitive materials and agricultural products in dry food.