3.4. Chilling in tanks and heat exchangers

This chilling method is used for liquid food products (milk, cream, juices, beer, wine, etc.). Refrigerants or secondary cooling agents are used on the cold side of the chilling device, which is operated in batch or continuous mode [4].

In the batch operation mode, the product fed into the tank is cooled using an external cooling jacket or an internal cooling coil. Figure 12 presents the schematics of a tank equipped with an external cooling jacket (2). The product is fed into the tank through the pipe (7); when the desired final temperature is reached, the product is purged from the tank through the discharge pipe (5).

Figure 9. Production of ice flakes. 1, water tank; 2, rotating refrigerated drum; 3, ice layer; 4, ice flakes; 5, ice chute; 6, scrapper blade.

Food Chilling Methods and CFD Analysis of a Refrigeration Cabinet as a Case Study http://dx.doi.org/10.5772/intechopen.69136 53

Figure 10. Fish chilling with ice. 1, 3, ice layers; 2, storage compartment; 4, fish.

Figure 11. Ice-filling machine. 1, chute; 2, 4, hoppers; 3, flexible hose; 5, flap; 6, discharge conveyer; 7, crates.

Heat exchangers are used in order to continuously chill the liquid products [3, 4]. Figure 13 presents a double pipe heat exchanger; the cooling medium circulates through the shell (3), while the product circulates through the inner pipe (4). The exchanger contains several sections that are coupled through flanges; the number of sections depends on the final temperature and flow rate of the fluids [9].
