Freeze dryer

Vacuum freeze-drying is also called drying, sublimation drying or freeze-drying for short. It is one of the drying methods for the purpose of storing items.

If the effect of external and internal factors can be reduced to a low degree, the object can be kept unchanged in a certain period of time.

Drying is to remove moisture from the interior of objects, because water is one of the necessary conditions for the growth of all living things. When the water content of organism is reduced to a certain extent, the organism is not easy or unable to grow and reproduce. Therefore, it can be stored for a long time; in addition, when there is water, some acid and alkali will dissolve, and some chemical reactions will occur in it, which will cause deterioration.

There are many ways of drying, such as drying, drying, drying, drying, spray drying, vacuum drying, freeze-drying and so on. Among them, only freeze-drying method is an ideal method to preserve living biological materials.

The freeze-dried products are sealed with vacuum or nitrogen to isolate air, especially oxygen, and then stored at low temperature, the three factors of water, air and temperature are controlled, so that the products can be effectively preserved in a long time.

Freeze drying technology was developed during the second world war due to the large demand for plasma and penicillin. Now it has been widely used in chemistry, pharmaceutical industry, food industry and scientific research, especially in biological drugs containing bioactive substances.

After liberation, China's freeze-drying industry has developed rapidly. Since 1952, it has been used in veterinary medicine and a number of large and medium-sized freeze dryers have been manufactured in China. Now all provinces, municipalities and autonomous regions have various types of freeze dryers.

In veterinary, it is mainly used for the storage of various veterinary microorganisms and the manufacture of various veterinary biological drugs. All kinds of drugs for preventing diseases of pigs, cattle, horses, chickens, ducks, geese, rabbits and dogs can not be separated from the freeze dryer.

Freeze drying belongs to marginal science, which involves physics, chemistry, biology and other knowledge, including refrigeration, vacuum, electrical, instrumentation and other technologies. Therefore, it is also a comprehensive professional science and technology.