Equipment for cooling

Carcasses are cooled with air in a cooling chamber, where standard refrigeration equipment maintains an air temperature of about 0°C and a movement speed of about 4-5 m/s. The time for cooling poultry from +40°C to +4…+6°C is about 2 hours.

The main advantages of air cooling are the low cost of the equipment and the absence of the risk of cross-fertilization of poultry.

However, there are a number of significant disadvantages that do not allow achieving high product quality when using air cooling: loss of presentation and windiness, significant shrinkage and loss of product weight. In addition, a number of difficulties arise due to the long cooling time and significant increase in the length of the conveyor.

The most common method is to immerse carcasses in a bath of chilled water. After slaughtering and/or heat treatment, the carcass is fed into the pre-cooling bath at a temperature of +40…+42 °C. Here, the temperature is lowered by several degrees and preliminary rinsing takes place. The carcasses are moved in the bath by a screw. Water from the pre-cooling bath is usually drained into the sewer.

In the next bath, the carcasses are cooled to +8 °C. The time spent in the second bath is the longest. Water from the second bath is usually returned to the water cooling system for cooling. After the main cooling bath, there are several options. The first option is that the carcass can be processed. However, this does not meet the requirements: the temperature of the carcass must not exceed +4 °C before packaging. The second method is cooling in a bath of ice water. The third method is air cooling.

In the case of cooling the carcass by immersion in a bath of chilled water, the cooling time is no more than an hour with proper water supply. The main disadvantage of this method is the need for disinfection to avoid cross-fertilization of meat with microflora.

Air-drip cooling combines the two methods listed above. Carcasses suspended on a conveyor are fed into a chamber where they are irrigated with water from nozzles and blown with cooled air. There is also a variant with periodic water supply and changes in air temperature in the chamber during the cooling process.

The air-drop cooling method combines the advantages of the two methods listed above: high carcass cooling rate, no weight loss due to drying, and no windage.

A significant advantage of using the proposed cooling method is the impossibility of fertilizing meat with microflora. The main disadvantages of the air-drop cooling method include the high cost of equipment and high operating costs.