level 1 guanfengmachine submitted about Aug 14, 2019


How to Freeze Dry Faster

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Choose a freeze Drying Equipment that allows heat to be added to the sample

The driving force in the lyophilization process is energy in the form of heat. In order for a molecule to undergo a phase change (solid to gas), energy must be provided. The more energy transferred to the sample, the faster the process.However the amount of energy that can be added is limited by the sample’s eutectic point, which is derived from the part of the sample mixture that has the lowest freezing point.

The most common accessories that provide heat to samples when freeze drying are heated product shelves. The product shelves of most Tray Dryers are microprocessor controlled, and the shelf temperatures are automatically changed according to a program that has been set and stored. Heated product shelves are commonly used with Clear Drying Chambers.

Many end users do not realize that when freeze drying with flasks and manifolds, heat still enters the samples. The heat source is essentially the room temperature that is usually around 20°C to 25°C. Increasing the amount of the sample that is in contact with the glass sides of the flask, will increase the heat transferred to the sample and will result in a faster lyophilization rate. Room temperature variances will certainly affect the required length of time to freeze dry.

The longest freeze dry runs will occur when the sample is placed on unheated product shelves within a chamber or placed inside the freeze dryer’s condenser. It is very difficult to transfer heat through an air gap and even more difficult when the air gap is under vacuum.For more information on freeze-drying, click GF Machinery


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    level 3 bougti

    So I was successfully able to freeze dry whole strawberries. I put 3 packages of frozen berries spread over two trays - 9 hours of freezing and 12 hours drying stage.
    The other items in the dryer at the same time were fairly low water. , ,

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