Liquid ring vacuum pump is widely used in vacuum drying process. The so-called vacuum drying is a kind of drying method, in which the material is placed under negative pressure and the boiling point under negative pressure is appropriately reached by heating or the material is dried through the melting point after solidification by cooling. The boiling point of water in the material under negative pressure decreases with the increase of vacuum. At the same time, vacuum pump clearance dehumidification is used to reduce water vapor content, which makes the solution such as water in the material get enough kinetic energy to separate from the material surface. Vacuum drying, because of the isolation of air under negative pressure, makes some materials which are easy to oxidize and other chemical changes in the drying process better maintain their original characteristics. It can also better protect materials by injecting inert gas and vacuum. Common vacuum drying equipment are: vacuum drying box, continuous vacuum drying equipment, etc.
The process of vacuum drying is to place the drying material in an airtight drying chamber and heat the drying material continuously while vacuuming with a vacuum system, so that the moisture in the material can diffuse to the surface through pressure difference or concentration difference. The water molecule can obtain enough kinetic energy on the surface of the material and overcome the mutual attraction between the molecules. The process of escaping to the low-pressure space of the vacuum chamber and being pumped away by the vacuum pump.
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 materials which are easy to oxidize and deteriorate, inflammable and explosive dangerous goods, etc. It can play a certain role in disinfection and sterilization of drugs, food and biological products, and can reduce the chance of material contamination or inhibit the growth of some bacteria.
Because the temperature of water is proportional to the vapor pressure in the process of vaporization, the moisture in the material can vaporize at low temperature during vacuum drying, which can realize low temperature drying. This is beneficial to the drying of thermosensitive materials in some medicines, food and agricultural by-products.
liquid ring vacuum pump Characteristics:
1. The structure is simple, the manufacturing accuracy is not high, and it is easy to process.
2. Compact structure, high pump speed, generally can be directly connected with the motor, without deceleration device. Therefore, with a small structure size, we can get a large amount of exhaust gas and occupy a small area.
3. Compressed gases are basically isothermal, i.e. the temperature change of compressed gases is very small.
4. Because there is no metal friction surface in the pump chamber, there is no need to lubricate the pump, and the wear is very small. The sealing between the rotating part and the fixing part can be accomplished directly by the water seal.
5. Inhalation uniformity, stable and reliable work, simple operation and convenient maintenance.
liquid ring vacuum pump Application:
The liquid ring vacuum pump was initially used as a self-suction pump, and then gradually used in many industrial sectors such as petroleum, chemical industry, machinery, mining, light industry, medicine and food. In many industrial processes, such as vacuum filtration, vacuum water diversion, vacuum feeding, vacuum evaporation, vacuum concentration, vacuum moisture regain and vacuum degassing, liquid ring vacuum pumps are widely used.