Vacuum pumps are widely used in the vacuum drying process. The so-called vacuum drying is a method of placing materials under negative pressure conditions, and appropriately heating them to reach the boiling point under negative pressure conditions or cooling them down to make the materials solidify and then drying through the melting point. How the material is dried. The melting point and boiling point of the water in the material will decrease with the increase of the vacuum degree under the negative pressure state. At the same time, the vacuum pump is used to dehumidify the gap to reduce the water vapor content, so that the water and other solutions in the material can obtain enough kinetic energy to separate from the surface of the material. Due to the isolation of air under negative pressure, vacuum drying can better maintain the original characteristics of some materials that are easily oxidized and other chemical changes during the drying process. It can also better protect the materials by injecting inert gas and then vacuuming them. Common vacuum drying equipment includes: vacuum drying oven, continuous vacuum drying equipment, etc.
The process of vacuum drying is to place the dry material in a closed drying room. While vacuuming with a vacuum system, the material to be dried is continuously heated, so that the moisture inside the material diffuses to the surface through the pressure difference or concentration difference, and the water molecules are on the surface of the material. After obtaining enough kinetic energy, after overcoming the mutual attraction between molecules, they escape into the low-pressure space of the vacuum chamber and are then pumped away by the vacuum pump. the
During 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, and the oxygen content is low, so it can dry materials that are easy to oxidize and deteriorate, flammable and explosive dangerous goods, etc. It can play a certain role in disinfection and sterilization of medicines, food and biological products, and can reduce the chance of material contamination or inhibit the growth of certain bacteria.
Because the temperature of water in the vaporization process is directly proportional to the vapor pressure, the moisture in the material can be vaporized at low temperature during vacuum drying, and low-temperature drying can be realized. This is beneficial to the drying of heat-sensitive materials in certain medicines, food and agricultural by-products.