The principle, characteristics, and applications of vacuum drying, and how vacuum pumps play a role in it?
Vacuum drying, also known as freeze drying, is a method that involves placing materials under vacuum negative pressure conditions to lower the boiling point of water. The boiling point of water at one atmosphere is 100℃. Under vacuum negative pressure conditions, the boiling point of water can be lowered to 80℃, 60℃, or even 40℃, allowing it to evaporate.
Date:
05 Jun,2025
Share:
Vacuum drying, also known as freeze drying, is a drying method that involves placing the material under negative pressure and applying appropriate heating to reach the boiling point under negative pressure or cooling to solidify the material before drying it.
Vacuum drying technology has been widely used in the production of health foods, especially in the drying of extracts from natural products. It is widely adopted because many effective components in natural products are not heat-resistant. Vacuum drying technology is also known as reduced-pressure drying. It is a method of drying in a sealed container by removing air and reducing pressure.
Under negative pressure, the melting point and boiling point of water within the material decrease with increasing vacuum. Simultaneously, the vacuum pump removes moisture from the gaps, reducing the water vapor content, allowing the water and other solutions within the material to gain sufficient kinetic energy to separate from the material surface. Because vacuum drying takes place under negative pressure, isolating it from the air, materials that are prone to oxidation or other chemical changes during drying better retain their original properties. The process can also be improved by injecting inert gas before vacuuming to better protect the material. Common vacuum drying equipment includes: vacuum drying ovens, continuous vacuum drying equipment, etc.
More
2025/06/05
No.1158, Sanjia Qihang Road, Jiaojiang New District,Taizhou City,Zhejiang Province