Before using food vacuum freeze drying machine, let us know first what is the vacuum freeze drying.
vacuum freeze drying is also known as sublimation drying, simply speaking, is to wet material freeze onto a eutectic point temperature, makes water become a solid ice, then under proper temperature and vacuum degree, make ice sublimation, for vapor in vacuum system of the water catchers will water vapor condensation, drying products is achieved.
After sublimation drying of food will not wrinkle, flavor and fresh food almost no difference.
It is now, more and more customers choose the cause of the vacuum freeze drying food.
to get sublimation drying food, implacably food vacuum freeze dryer.
Food vacuum freeze drying machine working process can be divided into three stages:
a, precool stage
food vacuum freeze drying machine work first step is to precool.
Precool is the material of water curing, dry products and dry before with the same shape, prevent bubbles when vacuum drying, concentration or contract.
Precool at the end of the temperature and the precool speed are the main factors affecting food quality.
2, sublimation drying stage
food vacuum freeze drying machine work, the first drying stage is the sublimation drying stage.
Frozen food in airtight vacuum container after heated, the ice crystals can sublimate for vapor and escape, so as to make the product dehydration.
When all the ice crystals to remove, the first phase of the drying process is completed.
At this point, the material removed about 90% of all water.
The remaining part of the water on to the next stage of drying.
3, analytic drying stage
food vacuum freeze drying machine work of the second stage of drying is analytic drying stage.
Parsing is to remove dry drying capillary wall and polar groups on the adsorption of moisture.
This phase is completed under high vacuum environment.
The second stage after drying, food residual moisture within the basic control in 0.
5% ~ 4%.
now, I believe everyone of food vacuum freeze drying machine working principle have a preliminary understanding.
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