Continuous on-the-line poultry chillers fall into four classifications--"drag" chillers, parallel-flow tumble chillers, counter-flow tumble chillers, and oscillating vat chillers.
"Drag" chillers consist of two vats. The first vat contains water at about 41F; the second vat contains water or slush ice at 32 to 33F. Carcasses, suspended on shackles, are dragged through the cooling medium.
Parallel-flow tumble systems for chilling also use two metal tanks. The first tank uses tap water, and the second tank contains slush ice or 33 to 35°F water.
Counter-flow tumble chillers are essentially the same as parallel-flow systems except that water circulates in the opposite direction from the carcasses.
Oscillating vat chillers consist of two tanks. Tap water is used in the first one for precooling, and the water in the second tank is cooled to 33 to 35°F.
Ice-packing operation includes removing chilled carcasses from chill vats,
packing them in containers, and capping poultry boxes with crushed or flake ice.
Klost processors now supply carcasses iced or dry packed with carbon dioxide.
Refrigeration systems, usually using ammonia, operate to make ice and to provide chilled water, and also for refrigerated storage. The waste heat is commonly rejected to the environment, usually with evaporative condensers, representing an excellent heat recovery opportunity.
