Product Freezing Stage on the freeze Dryer, something need to Note

The freezing stage is extremely important in the freeze-drying process because it affects not only sublimation quickly or slowly of the ice in product, but also the proper operation of the related components. Therefore, we need to pay more attention to this first step to ensure the most effective drying process.

Freeze drying is a fully automatic operation process, the stages will take place consecutively, the next stage only works well when the previous stage works properly. For example, the product freezing stage ensures good cooling, the temperature on the product will reaches the set level, -20oC to -30oC, then the next vacuum stage can ensure a low enough pressure for the sublimation process to take place effectively. Freeze dryer is a complex drying machine, so customers need to understand the operating principle as much as possible, on this website there is enough information for users to learn.

The freezing time often need 4-7 hours depending on the type of product, thin, flat, watery products, the freezing time is faster than the bulky, round shape, less contact… Therefore, users also need to pay attention to this factor for the product freezing stage to achieve good results.

When the product freezing process is satisfactory, the temperature parameters at the sensors on the trays will be basically the same as the image above, for example setting the freezing temperature at -25^oC, the temperatures on controller screen Đ – V – T – X will be from -20 to -25^oc or lower are suitable. Then the next steps of the dryer will comply with the requirements and give good drying results.

In case the frozen product is not sufficiently cooled, sublimation occurs worse because the ice crystals are not small enough, in some products this problem will damage the product texture or not dry enough.

Another problem when the product is not frozen, the subsequent process of vacuum suction will not be able to reach the required pressure for the effective sublimation drying stage, then the drying principle will change to vacuum drying, water will boils at a low temperature when the pressure is reduced. As a result, the product will be shrinked, deforming, drying for a long time, and the vacuum pump will suck a lot of water vapor through it, this problem will damage the vacuum oil. Readers need to learn more about the pressure parameter on the freeze dryer and how the temperature on the freeze dryer will change during the drying process.

So, with the above basic information, readers have understood more about the product freezing stage and important notes at this stage. Customers need more advice on drying products, please contact Mactech Dryer to be provided with the necessary information, thank you for learn about the shared content.