ABSTRACT
Milk and milk products are nearly always cooled artificially. Cooling is done in refrigeration installations, for which electrical energy is required. The basic principle of refrigeration installations is that evaporative heat or enthalpy is removed from an environment with a simultaneous cooling. Absorption refrigeration units are used mainly for smaller units such as refrigerators. Compression refrigeration installations can also be considered as heat pumps, as they produce heat of a lower temperature by applying mechanical energy. During the cooling process the refrigeration installation must operate continuously; the refrigeration medium is the cold carrier. Ice water-based refrigeration can be designed without a storage basin. Refrigeration tubes covered with frost or ice must be thawed regularly, otherwise heat transfer is significantly reduced because of the low conductivity of ice. In order to avoid heat losses, all refrigeration pipelines are insulated. In dairies, compression refrigeration units are most often used.
