In its most basic form, FC has been employed since as far back as the Middle Ages. Beer or wine in wooden barrels would be exposed to the cold winter nights, causing water to freeze along the barrel walls and leaving a concentrated product in the middle of the ice shell.
In more recent times, a few companies have tried to commercialize FC processes. The main problem with most of these attempts was the difficulty in separating the ice from the concentrate. Filter presses, centrifuges, and various types of wash columns have been used with limited success . Unacceptable losses of product with the ice, low production capacities, and high equipment cost were normally associated with FC processes during this time. Professor H. A. C. Thijssen, working at the Technical University of Eindhoven, was the first to develop a practical solution for this problem. His solution consists of two parts. An efficient crystallization process provides ice crystals of sufficient size and purity to allow proper separation, and an efficient wash column provides for complete separation of the ice and concentrate, using the melted ice to wash the incoming crystals without recycling the wash water.
Thijssen's original work provided the basis for the development of the present NFC process. The following sections describe the general NFC process and equipment used in the wastewater project. Commercial applications in the food industry use the same basic process.
The NFC can be separated into the two parts noted in Thijssen's work, the crystallization section and the separation section .
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