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E-mail
15093177890@163.com
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15093177890
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B06-1 Qidi Zhenghang Intelligent Manufacturing Industrial Park, Intersection of Xinxiang Road and Luoning Road, Shangjie District, Zhengzhou City, Henan Province
Zhengzhou Kewangda Biological Instrument Co., Ltd
The working principle and wide application of in-situ freeze-drying machine
Date: 2025-06-12Read: 12
In situ freeze dryer is a device based on vacuum freeze drying technology, which mainly relies on the three-phase changes of water (solid, liquid, gas) to achieve material drying through low-temperature freezing and vacuum sublimation. This technology is widely used in fields such as medicine, biological products, and food to maximize the retention of active ingredients and structural characteristics of materials. The following are its core principles and typical applications:
1、 Working principle
1. Pre freezing stage
The material rapidly freezes in a low-temperature environment (usually ≤ -50 ℃), allowing the internal moisture to form uniform ice crystals and avoiding excessive ice crystal damage to the material structure. The refrigeration system (liquid nitrogen or compressor) provides a low-temperature environment to ensure complete solidification of the material.
Key point: Rapid freezing reduces ice crystal size and protects the activity of thermosensitive substances such as proteins.
2. Primary drying (sublimation) stage
In a vacuum environment (pressure ≤ 610.5Pa), thermal energy is provided through a heating system (mainly radiation heating) to directly sublime ice crystals into water vapor without passing through the liquid state. The vacuum pump continuously extracts water vapor to maintain a low-pressure environment.
Key point: The triple point (0.01 ℃, 610.5Pa) is the critical condition for sublimation to occur, avoiding thermal denaturation.
3. Analyze the drying stage (excluding residual moisture)
Heat up to a higher temperature (usually 0-30 ℃) to remove bound water from the material. The secondary dehydration technology ensures that the moisture content is reduced to ≤ 5%, ensuring long-term stability.
4. Equipment core components
Split design: Separation of drying chamber and cold trap, thermal conductivity of silicone oil improves energy efficiency;
Automated control: Real time monitoring of temperature and pressure parameters, optimizing drying curves.
2、 Widely applicable fields
1. Biopharmaceuticals
Protein/vaccine preservation: Avoid denaturation in a low-temperature environment, with a biological activity retention rate of ≥ 95% after freeze-drying, making it easy to transport and store for a long time.
Live bacterial preparations, such as BCG vaccine and oral dysentery live vaccine, have significantly improved stability after freeze-drying.
2. Food industry
Meat/Fruit and Vegetable Processing: Freeze dried beef chunks, freeze-dried fruits, etc. retain their original flavor and nutrition (with a vitamin loss rate of<5%), have good rehydration properties, and are suitable for leisure snacks and outdoor food.
Pet food: Non additive freeze-dried meat products meet high nutritional requirements.
3. Chemical Engineering and Research
Pilot production: Flexible adaptation to experimental scale, automatic plug pressing function improves efficiency.
Preservation of active substances: Enzymes, cellular tissues, etc. have stable structures after freeze-drying, making them easy to study.
3、 Technical advantages
1. Structural protection: Avoid ice crystal melting and high-temperature damage, maintain a porous sponge like structure, and quickly rehydrate.
2. Efficient and energy-saving: The split type cold trap design reduces energy consumption, and the thermal conductivity of silicone oil improves heat utilization efficiency.
3. Long shelf life: Moisture content ≤ 5% inhibits microbial growth, and can be stored at room temperature for several years.
The in-situ freeze dryer, with its mild drying method of low temperature and low pressure, has become an ideal choice for storing thermosensitive substances, and the demand in the fields of biomedicine and high value-added food will continue to grow in the future.