Snow formation inside IQF freezers is strongly linked to the process of dehydration, which occurs during freezing and is represented by water loss through the product’s membrane when it meets the cold air flow inside the IQF tunnel freezer.
During the process of dehydration, the products will also suffer a loss of weight. The humidity that is transferred from the product into the air will saturate it, and at the maximum point of air humidity (100% saturated), snow is created. This phenomenon is called precipitation and it is the same as when rain or snow is created out in the atmosphere.
The major factor responsible for the occurrence of precipitation during the IQF process is the large quantity of wet and warm product that makes contact with the cold temperatures inside the IQF freezer. After precipitation, the level of saturation decreases and even more moisture can be transferred from the product to the air, leading to more weight loss for the product transported on the bedplate inside the freezer.
Therefore, if snow formation inside IQF freezers is an indicator of product loss and dehydration, how can we minimize the level of dehydration?
First of all, the process of precipitation and thus sublimation needs to be kept under a specific level, with the help of optimal aerodynamics which ensures less disruption of the air flow and better air speed.
In order to minimize dehydration you need to avoid precipitation and thus sublimation, have better aerodynamics (less disruption of the air flow) and better air speed.
Considering that temperature variations inside an IQF freezer are a common thing, snow formation cannot be completely prevented but, thanks to its advanced design features, the IQF tunnel freezer can successfully minimize snow formation, increasing the yield of the overall production.
The IQF tunnel freezer benefits of unique fans, which can be individually adjusted in order to ensure the optimal speed for the perfect air velocity and air pressure. Thanks to the good control over the aerodynamics inside the IQF tunnel freezer, the level of air humidity remains constant and the process of precipitation is significantly prevented, ensuring a level of product dehydration between 0,1% and 1%.
The fact is that the snow building up inside your freezer is product loss, and that is because an IQF freezer is a closed system and the humidity creating the precipitation doesn’t have anywhere else to come from than from the products you are freezing.