In various heating and drying methods under normal pressure, the color, aroma, taste and nutrients of the material are subject to a certain degree of loss due to the heat of the material. If the method of vacuum drying is used, the loss of quality can be reduced by the fact that the air is isolated under a negative pressure state, and a material which is susceptible to chemical changes such as oxidation during the drying process can better maintain the original characteristics. Vacuum drying is to place the dried food material in a closed drying chamber. While vacuuming with a vacuum system, the material to be dried is heated appropriately, so that the moisture inside the material diffuses to the surface through pressure difference or concentration difference. Sufficient kinetic energy is obtained on the surface of the material, and after overcoming the attraction between the molecules, it escapes into the low-pressure air of the vacuum chamber and is removed by the vacuum pump.
Vacuum drying, also known as analytical drying, is a drying method in which the material is placed under a vacuum condition, and the boiling point under a negative pressure state is appropriately heated or the material is solidified and then dried by a melting point by cooling. Vacuum drying technology has been widely used in the production of health foods, especially the extraction of natural product extracts, which are widely used for vacuum drying because many of the functional ingredients in natural products are not resistant to high temperatures. Vacuum drying technology, also known as vacuum drying, is a method of removing air in a closed container and drying it under reduced pressure.
Under the negative pressure state, the boiling point of the melting point decreases with the increase of the vacuum degree. At the same time, the vacuum pump gap is used to reduce the water vapor content, so that the water and other solutions in the material can get enough kinetic energy to leave the surface of the material. Vacuum drying Because the air is isolated under the negative pressure condition, the chemically changed materials which are easily oxidized during the drying process can better maintain the original characteristics, and the material can be better protected by vacuuming after injecting the inert gas.
Rotary vane vacuum pumps are widely used in vacuum drying, and vacuum pumps are also used as a central vacuum system for wood processing to increase efficiency, maintain wood properties and minimize costs. It took a few weeks to use ordinary drying. After using the rotary vane pump of EVP brand it can be shortened to three or four days. During the drying process, the pressure in the drying chamber is gradually minimized. The drying chamber is filled with high-pressure steam, which is pumped away to avoid cracks and color changes in the wood. These changes are usually due to excessive oxygen levels.
1. Improve the stability of the use of wood and wood products.
2. Improve the strength of wood and wooden parts. When the wood moisture content is lower than the fiber and saturation point, the strength of the wood will increase as the moisture content of the wood decreases.
3. Prevent the enamel and decay of wood.
4. Reduce the weight of the wood.
Key words: vacuum drying pump, rotary vane vacuum pump
Edited by: Emily Fu / Shanghai EVP Vacuum Technology Co., Ltd.