Lyophilization Technology of Vacuum Freeze Dryer

Lyophilization of a Vacuum Freeze Dryer was used to prepare tissue samples for structural studies (eg, electron microscopy studies). Freeze drying is also used in chemical analysis to obtain dried samples or to concentrate samples to increase analytical sensitivity. Freeze-drying stabilizes the sample components without changing the chemical composition, making it an ideal analytical aid. Freeze drying can occur naturally. In the natural case, this process is slow and unpredictable. Through the freeze-drying system, people have improved and subdivided many steps to speed up the process.

Bell-type Vacuum Freeze Dry Machine: The freeze-drying chamber and the cold trap are upper and lower structures, and the freeze-drying chamber has no pre-freezing function. This type of lyophilizer requires manual operation when it is transferred to the drying process after the material has been pre-frozen. Most of the experimental Freeze Dry Machine are bell-type, with a simple structure and low cost. Most of the freeze-drying chambers use a transparent plexiglass cover to facilitate the observation of the lyophilization of the material.

In-situ freeze-drying machine vacuum freeze-drying machine: the freeze-drying chamber and the cold trap are two independent chambers, and the shelf in the freeze-drying chamber has a cooling function. After the material is placed in the freeze-drying chamber, the material is pre-frozen and dried. The process does not require manual operation. This type of freeze dryer has a complicated manufacturing process and high manufacturing cost, but the in-situ freeze dryer is the development direction of the freeze dryer, an ideal choice for lyophilization process, especially suitable for medicine, biological products and other special products.

Ordinary shelf type vacuum freeze-drying machine: The material is bulk-packed in the material tray and is suitable for lyophilization of food, Chinese herbal medicine and powder materials.

Vacuum lyophilizer with gland type device: suitable for drying of bottled materials in Xilin. When lyophilized, prepare the materials in the vials as needed, float and cover the caps, freeze-dry them, and operate the gland mechanism after drying. The bottle cap can be pressed to avoid secondary pollution, re-adsorb moisture, and easy to store for a long time.

Principle and Structure of Vacuum Freeze Dryer

The food vacuum Freeze Dry Machine not only maintains the freshness and nutrition of the food, but also prolongs the shelf life of the food. What is the principle and composition of the Vacuum Freeze Dryer ?
The vacuum Freeze Dry Machine is a drying technique in which a wet material or a solution is frozen to a solid state at a lower temperature and then the water therein is directly sublimated into a gaseous state without being liquid, and finally the material is dehydrated.

The Principle of Food Vacuum Freeze Dryer principle

The constant supply of heat and the continuous elimination of steam generation. In the initial stage, if the material temperature is relatively high, the latent heat required for sublimation can be taken from the sensible heat of the material itself. However, as the sublimation progresses, the temperature of the material quickly drops to a temperature equilibrium with the vapor partial pressure of the drying chamber. At this time, if there is no external heating, the sublimation drying stops. In the case of external heating, if the steam generated by sublimation is not eliminated in time, the partial pressure of steam will increase and the temperature of the material will increase. When the material freezes, the ice crystals in the material will melt. Freeze drying will not work.

The structure of Food Vacuum Freeze Dry Machine

(1) The drying box has two main forms of cylindrical and square, each having advantages. The cylindrical shape is easy to manufacture, but the space that cannot be utilized is large; the square is opposite, the space utilization rate is high, but manufacturing is difficult.

(2) Most of the heating system uses radiation heat transfer. The radiant panel is made of anodized aluminum. The heat transfer medium has heat transfer oil, saturated water, secondary steam, organic solvents such as propylene glycol, glycerin, etc. The heat source is high pressure water vapor.

(3) The vacuum system adopts mechanical vacuum pump, including Roots pump + oil seal pump and Roots pump + Roots pump + atmospheric injection + water ring pump. More information click gf-machine