Freeze drying
Freeze-drying is a process that is used in food industry and in some manufacturing industries, such as pharmaceuticals. Processes, in the first freezing the product, and then removal of water by sublimation, where water is in solid state facing directly in pairs, bypassing the liquid state. For realization of the process of sublimation, heat gently added product is stored under vacuum chambers, such as shown in Fig. 1.5. To achieve vacuum combination of cold and mechanical pumping works. The mechanical pump, mainly, to remove air and other noncondensible gases and cooling system chills evaporator may -50C (-58F). Water from the buildup on the evaporator coils in the form of frost. Refrigeration is thus an initial frosts, and the dimensions of the evaporator of the vacuum chamber.
The pharmaceutical industry uses freeze drying for certain products, where the removal of water at high temperatures can damage the product. The share of food products, which have preserved the freeze drying is very low, but the process finds a role for specific applications. As soon as the food product is freeze dried, it needs no further cooling and cooking is the addition of water restores product and taste surprisingly close to the original quality.
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Industrial