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A freeze dryer or lyophilizer is a device used to remove water in a product by freezing it and then turning the frozen water directly into vapor- without going through a liquid state. This is known as sublimation and the original structure, color, flavor and nutritional value of the product are maintained within years without refrigeration. Freeze drying is radically different to the traditional dehydration, which involves the use of heat and may destroy sensitive compounds. We are Jiangsu Bolaike Refrigeration Science and Technology Development Co., Ltd. and we have been producing freeze drying equipment since more than 20 years. A full introduction of freeze dryer machines is provided below.
1. How a Freeze Dryer Works: The Three Stages
A freeze dryer has three stages of operation. First, freezing: the product is refrigerated to a temperature lower than the eutectic temperature (usually -40 °C or lower), and all the moisture is frozen in the form of ice crystals. Second, main drying (sublimation): the frozen product is put under the vacuum and low power heat is added. The ice is immediately changed to water vapor and is pumped out of the chamber through the vacuum system-there is never any liquid water formed. Third, secondary drying (desorption): a slightly increased temperature will dry the product of all the bound water molecules to a left-over 1-4% of moisture. This low moisture content inhibits the growth of microbes and chemical reactions and provides freeze dried products with a shelf life of 20-30 years in the absence of preservatives.
2. Key Components of a Freeze Dryer Machine
All freeze dryers, regardless of type (household or industrial) have four fundamental systems. The product is frozen by the refrigeration system and water vapor captured on cold condenser coils. Low temperatures of sublimation are made possible by vacuum chamber to remove air pressure. The heat system is used to generate controlled uniform heat to drive sublimation without melting the product. The control system measures temperature and pressure during the cycle, and automatically sets the parameters to achieve the best results. They are designed by Jiangsu Bolaike to be energy-efficient and reliable. Our industrial models have stainless steel chambers, industrial grade compressors and programmable logic controllers (PLCs) to ensure full automation.
3. Types of Freeze Dryers for Different Applications
Freeze dryers are in various sizes to attract various users. Household freeze dryers are small countertop preservation appliances used in home food preservation- ideal in preserving garden vegetables, fruits, meats and even entire meals. Laboratory freeze dryers are bench top or floor mounted devices with exact temperature control, utilized in research, pharmaceutical development, and small scale nutraceutical manufacturing. Pharmaceutical freeze dryers are very large and sterile systems that are created with the purpose of producing vaccines, antibiotics and injectable drugs in GMP compliant production. Food freeze dryers are heavy and large industrial machines that produce frozen coffee, instant meals, fruits, vegetables, seafood and herbs in large quantities. Jiangsu Bolaike produces each of the four types, starting with small household units, and up to large production lines covering 200+ square meters of shelf space.
4. What Products Can Be Freeze Dried
Freeze drying is very versatile. It also preserves coffee, fruits, vegetables, seafood, meat, dairy and entire ready to eat meals in the food industry. It stabilizes vaccines, antibiotics and diagnostic kits in the pharmaceutical industry. It stores probiotics, enzymes, herbal extracts and dietary supplements in the nutraceutical industry. Freeze drying of biological samples (blood plasma, tissues) and even flowers is used to preserve it over a long period. The most important thing is that the product should not be affected in the process of freezing. Freeze dryers in Jiangsu Bolaike have been adopted to freeze vegetables, fruits, coffee, flowers, herbal extracts, seafood, nutraceuticals, and biological and chemical products- known to customers in the U.S, Asia, and Europe.
Conclusion
Freeze dryer involves freezing and sublimation to remove water, which maintains color, nutrition and flavor over decades. It works in three phases (freezing, primary drying, secondary drying) and has refrigeration, vacuum, heating and control systems. Various scales can be used in household, laboratory, pharmaceutical and food production. Jiangsu Bolaike is experienced in manufacturing efficient, energy saving freeze dryers with ISO9001 and CE certification as well as 56+ national patents. Call us now to get the appropriate freeze dryer that fits in your product or book a factory tour in Changzhou, China.