Laboratory freeze dryer is abbreviated as laboratory freeze dryer. Freeze-drying technology is a technical method of pre-freezing water-containing items, and then sublimating their water in a vacuum state to obtain dry items. The freeze-dried items are easy to store for a long time, have good rehydration and maintain the original biochemical properties.  They are widely used in the fields of medical pharmaceuticals, biological products, food industry, Chinese herbal health products and new materials.

 

Laboratory freeze dryer composition system:

 
 1. Control system: It is composed of programmable controller, touch screen, peripheral relays, sensors and so on.
 
 2. Refrigeration system: It is composed of refrigeration compressors and auxiliary facilities, providing cold sources for drying boxes and cold traps.  (In the refrigeration system, in addition to the high and low pressure gauges, there is also a pressure controller. When the high pressure is too high, the high voltage relay will act and the compressor will stop working.)
 
 3. Circulation system: Freeze drying and heating are a process technology that relies on temperature difference to cause material transfer.  The refrigeration and heating of the shelves are carried out through the heat transfer of heat transfer oil. In order to make the heat transfer oil circulate continuously in the whole system, we have added a shielded circulation pump in the pipeline.
 
 4. Vacuum system: It is composed of drying oven, cold trap, vacuum valve, vacuum pump, vacuum pipeline, vacuum measurement gauge and other parts.  The vacuum pump group has a strong suction capacity. On the one hand, the water in the drying box is sublimated in a vacuum state. On the other hand, the system forms a vacuum pressure difference between the cold trap and the drying box, so that the water in the drying box is sublimated and then cooled.  Trap capture.
 
 5. Hydraulic system: mainly used to press the cork into the bottle mouth at the end of drying.

 

Laboratory freeze dryer process:

 
 1. Preparation of products (pretreatment): such as drug cultivation, sterilization, subpackaging, bottle washing, half stoppering, etc., selection of food raw materials, cleaning, cutting, enzyme elimination, subpackaging, etc.
 
 2. Freezing (pre-freezing) of the product: freezing the product into a solid state.
 
 3. The first stage of drying (sublimation drying): the ice crystals in the product are removed by sublimation.
 
 4. The second stage of drying (desorption drying): Part of the moisture remaining in the product is evaporated at a higher temperature to make the residual moisture meet the predetermined requirements.
 
 5. Sealed packaging: dried products should generally be sealed and packaged under vacuum or filled with inert gas to facilitate storage.
 
 freeze-dried powder
 
 

Advantages of freeze-drying technology

 
 1. Freeze-drying is drying at low temperature, which will not denature proteins, but can make microorganisms lose their biological activity.  This is especially suitable for dry storage of biologically active products, biochemical products, genetic engineering products and blood products with poor thermal stability.
 
 2. Due to the low-temperature drying, the loss of volatile components in the substance and heat-denatured nutrients and aromatic components is very small, so it is a high-quality drying method for chemicals, medicines and food.
 
 3. During the low-temperature drying process, the growth of microorganisms and the action of enzymes are almost impossible, so that the original properties of the material can be best maintained.
 
 4. After drying, the volume and shape are basically unchanged, and the substance is sponge-like without drying shrinkage. When rehydrating, the contact surface with water is large, and it can quickly return to its original shape.
 
 5. Because it is generally dried under vacuum, there is very little oxygen, so that the easily oxidized substances are protected.
 
 6. Freeze-drying technology can remove 95% to 99.5% of the water in the material, and the product has a long shelf life.
 
 

Application field of laboratory freeze dryer

 
 1. Biological products and pharmaceuticals: preservation of antibiotics, antitoxins, diagnostic supplies and vaccines.
 
 2. Advanced nutritional products and Chinese herbal medicines: royal jelly, honey, pollen, Chinese herbal medicine preparations, etc.
 
 3. Microorganisms and algae: long-term preservation of various bacteria, yeast, enzymes, protozoa, microalgae, etc.
 
 4. Preparation of ultrafine powder: prepare ultrafine powder such as Al2O3, ZrO2, TiO2, Ba2Cu3O7~8, Ba2Ti9O20, etc.
 
 5. Food drying: coffee, tea, meat, fish and eggs, seaweed, fruits, vegetables, spices, tofu, convenience food, etc.
 
 6. Biological specimens and biological tissues: make various animal and plant specimens, and dry and preserve marginal tissues such as skin, bone, aorta, heart valve, etc. for animal xenograft or homologous transplantation.
 
 7. Other aspects: Catalysts in the chemical industry can increase the catalytic efficiency by 5 to 20 times after freeze-drying; freeze-drying plant leaves and soil are used to study the effects of soil, fertilizers, and climate on plant growth and the effects of factors; humidity  The wooden cultural relics, flooded book manuscripts, etc. are dried by freeze-drying method, which can keep the original state to the greatest extent.