What is the use of liquid nitrogen in a small freeze dryer?
Drying is a very old operation, but heating and drying of powders and biological products often leads to irreversible agglomeration of the particles, especially in the preparation of ultrafine powders, in which the nanoparticles in the liquid phase are dried and aggregated into agglomerates that are difficult to disperse. Esters are mainly because water is dispersed in the pores between the particles during the ordinary drying process. The surface tension causes an extremely high additional pressure and compacts the particles together to form a mass.
Freeze drying can avoid this problem. Freeze-drying is to freeze the gel or blood into a solid, then vaporize and remove water under reasonable conditions by sublimation, because the vaporization process of ice does not affect the coalescence of solid particles, so it can be well preserved. . The particles are not compressed and agglomerated. In addition, freeze-drying is very suitable for the treatment of biological products, such as blood, because it does not operate at high temperatures and can prevent deterioration of biological products.
Application of liquid nitrogen in small freeze dryers:
Liquid nitrogen freeze-drying is one of the most widely used freeze-drying equipment in the modern pharmaceutical industry, and it is increasingly favored in the freeze-drying industry. The liquid nitrogen small-scale freeze dryer has advanced technology and overcomes many shortcomings inherent in the original compressor refrigeration system, and can better meet the requirements of the modern freeze-drying process. It is 2-3 times longer than mechanical refrigeration, which can meet the requirements of conventional freeze-drying and rapid crystallization process. Especially after SIP, it can directly start the refrigeration system, shorten the interval between two freeze-drying, shorten the batch operation time and improve production. effectiveness. VE production capacity.
The effect of small freeze dryer:
1. Many heat sensitive substances are not denatured or inactivated.
2. At low temperatures, some of the volatile components in the material are very small.
3. When there is little oxygen when vacuum drying, it can protect some oxidizing substances.
4, drying can remove 95% ~ 99% of water, after drying, the product can be stored for a long time without deterioration.
5. Since it is dried in a frozen state, the volume is almost constant, and the original structure is maintained, and concentration does not occur.
6. During the freeze-drying process, the growth of microorganisms and the action of enzymes cannot be performed, so that the original characteristics can be maintained.
7. After drying, the material is porous and sponge-like. When added with water, it dissolves quickly and completely restores its original properties almost immediately.
8. Since the water in the material exists in the form of ice crystals after pre-freezing, the inorganic salts dissolved in the water are evenly distributed in the material. When sublimation occurs, the dissolved substances in the water will precipitate, thereby avoiding surface hardening caused by inorganic salts. . The inorganic salts carried by the water migrate from the interior of the material to the surface.
9, because the material is in a frozen state, the temperature is very low, so the temperature of the heating source is not high, the use of room temperature or low temperature heater can meet the requirements. There is no need for insulation and there is not much heat loss, so the use of heat is very economical.