There are various drying methods, such as sun drying, boil drying, drying, spray drying and vacuum drying, etc., but these drying methods are usually carried out at temperatures above 0°C or higher. Compared with other technologies, freeze-drying is a technology that uses the principle of sublimation for drying, It is a process in which the dried material is quickly frozen at low temperature, and then the frozen water molecules are directly sublimated into water vapor and escape in an appropriate vacuum environment.
The lyophilization vacuum drying process includes three stages: pre-freezing, sublimation and re-lyophilization. Reasonably and effectively shortening the freeze-drying cycle has obvious economic value in industrial production. The application range of vacuum freeze-drying technology is very wide, as long as it is water-containing, non-toxic and non-corrosive substances, it can be made into freeze-dried products by freeze-drying technology. Almost all agricultural and sideline products, such as meat, poultry, eggs, aquatic products, vegetables, fruits, etc., can be made into freeze-dried food, condiments, instant food, etc. At present, the most widely used freeze-drying technology is the food industry, the biopharmaceutical industry, the medical industry, and the health care product industry.
Compared with other drying methods, freeze dryer has the following advantages:
1. Freeze drying is carried out at low temperature and is therefore particularly suitable for many heat-sensitive substances. Such as proteins, microorganisms and the like will not denature or lose biological activity.
2. Since it is dried in a frozen state, the volume is almost unchanged, and the original structure is maintained without condensation.
3. The material dried by the freeze dryer is loose, porous and spongy. After adding water, it dissolves rapidly and completely restores its original properties almost immediately.
4. Since the freeze dryer is dried under vacuum, there is very little oxygen, so some easily oxidized substances are protected.
5. The loss of some volatile components in the material is very small when the freeze dryer is dried at low temperature.
6. During the freeze-drying process, the growth of microorganisms and the function of enzymes cannot be carried out, so the original packaging can be maintained, and the drying of the freeze-drying machine can remove more than 95-99% of the water, so that the dried product can be stored for a long time without deterioration.
7. Since the water in the material exists in the form of ice crystals after pre-freezing, the dissolved inorganic salts dissolved in water are evenly distributed in the material;
8. The added value of the final product is high due to the advantage of freeze-drying that can maintain the original properties of the raw materials.
Our engineers will provide suitable drying proposal according to customers' different raw materials and different requirements for final products, such as microwave drying equipment, vacuum microwave drying equipment, hot air drying equipment, freeze dryer, multi-layer mesh belt oven, etc.
Jinan Kelid Machinery Co., Ltd sincerely provides suitable proposal and high-quality machines, welcome to inquire.