Principles of Ice Cooling

Ice cooling, the oldest among cooling methods, still is very effective for many crops and packaging methods. Heat is rapidly removed from the produce by direct contact with the melting ice, which is in equilibrium with the melt water at 0 OC. It can be used on a variety of commodities and is particularly effective on dense and palletized packages. When sufficient quantities of ice are used it can continue to protect and insure against cold chain failure. It also provides a high relative humidity environment, reducing moisture loss of the produce.

AllFresh offers versatile storage and delivery systems that can meet your specific needs, even if you are upgrading a facility with space limitations. Ice production, storage and delivery systems can meet peak loads up to 400 pallets (300 MT) per day. Ice injection systems can be designed to meet your needs, from manual ice slurry injection guns to automatic ice injectors that can ice up to 20,000 cartons per day.

Block Ice

When local produced block ice is available it can offer a convenient source of cooling capacity. Block ice can also be transported for considerable distances without requiring refrigeration and with little loss from melting.

But for more remote areas, the use of block ice can present supply and storage problems. More efficient chip or flake ice plants provide an alternative in either case. Because of its large volume-to-surface-area ratio block ice can be transported for good distances without refrigeration with only small loss.

Icing Methods

Individual Package Icing

The simplest icing method is to add crushed ice manually to the top of each carton that contains the produce. The methods is most effective when the ice touches the produce or the melt water has clear access to it. When these conditions do not exist, cooling must rely on convection rather than conduction, and temperatures can be inconsistent. Usually extra space must be allowed in the container to hold the ice. After packing, each carton must be opened, iced, and re-closed. This process is slow and labor intensive, but it can be automated with the use of power conveyors and ice dispensing hoppers.

Liquid Icing

The block or plate ice is ground or pulverized to a size of approximately 5 mm or less and mixed with water to form a thick slurry. It is pumped and guided through a hose and guided over the produce in open cartons or containers. Efficiency is improved if the containers are carried past an icing station on a power or gravity-fed conveyor system. The slurry allows for good penetration into the available open space in the container and results in faster and more even cooling.

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