3. Processing industries

3.1 The cold

Cooling and deep-freezing of perishable foodstuffs can be used for all types of product: raw, pre-processed, finished and of various sizes. Chillers and freezers are naturally very different from one another, so that they can be adapted to each individual case. We'll confine ourselves to describing these processes, leaving aside workshop air-conditioning systems and positive and negative-temperature cold rooms.

Since freezing and chilling have to be carried out quickly to meet industrial production rates and sanitary and veterinary standards, the following question needs to be asked for every project: should a refrigeration machine be used for "mechanical refrigeration", or should a low-temperature refrigerant be used for direct contact with the...