Food, Pharmaceuticals, Plastics & More
Food freezing is either conducted by a mechanical freezing system or a cryogenic freezing system - both of these varying widely from one another. The cryogen freezing technologies are known to produce many high quality frozen foods in contrast to the traditional mechanical freezing methods.
Cryogenic freezing involves freezing outer layers of the food beyond its actual freezing point, while the inner portion of the product stays warm. The final temperature however is not its temperature as it exits the cryogenic process. It is only after full equalization that the final temperature can be known, which is usually after a period of about 15 minutes.
Food and pharmaceuticals, as well as other medical materials can be frozen using cryogen. In a process known as cryogenic grinding, the material is cooled or chilled and then reduced to a small particle size. When chilled by dry ice, liquid carbon dioxide or liquid nitrogen, the material can be finely ground to powders suitable for electrostatic spraying and other powder processes. Cryogenic grinding is used in research for plant/animal tissue, food, drugs and plastics.
In comparison to mechanical freezing system and techniques, cryogenic process generally require a smaller capital investment and prevent significant energy and preventive maintenance costs and high usage of plant space. Cryogenic freezing is often characterized by high cryogen (liquid nitrogen or carbon dioxide) cost. However, choosing a freezing method depends on production costs, facilities, methods and systems available, as well as consumer preferences.