Types of Hydro-coolers

Continuous Flow Hydro-cooler The flow-through hydro-cooler allows the produce, individually, in bulk bins or in cartons, to pass along a conveyor under a shower of chilled water.Warm produce
	is placed on one end of the conveyor, and cooled produce is removed at the opposite end. The produce can enter and exit on a conveyer system, or it can be placed on and removed manually or mechanically. The product cooling rate (a function of packaging, also!) and the volume of the produce to be cooled over a specific
time determine the size of the equipment necessary. Optional variable speed conveyor belts can be useful in adapting the equipment to a variety of produce needs.

Batch Hydro-coolers A batch-type hydro-cooler is an enclosure without conveyors. Palletized cartons or bulk bins of produce are loaded into the front of the enclosure, usually with a fork lift.
	A door or curtain is closed, and a continuous flow of large quantities of chilled water is showered down upon the produce. It is collected into a sump at the bottom, filtered, re-cooled, and re-cycled. Units can be of any size, the smallest usually cooling one pallet (1 MT) at time up to larger batch units that can cool eight pallets (6 MT) or more in each cycle.

Containers and Stacking Considerations for Hydro-cooling

An important factor in operating efficiency is container design and the stacking pattern. These elements greatly affect the heat transfer process in hydro-cooling.

A variety of produce packages have been successfully used in hydro-cooling. Plastic totes and bulk bins are popular in pre-packaging use. For products packaged and palletized before cooling wire-bound wooden crates, waxed fibreboard cartons, and mesh poly bags are alternatives.

Palletized packages must be carefully stacked to allow water to enter the packages. If the water flows around and not through the packages, little cooling will occur, or much too slowly. Produce in waxed fibreboard cartons with solid tops are particularly difficult to cool unless the tops and bottoms are designed to allow easy access and egress of the falling water.

In any selection, allowance for some open space between bulk or packaged product must be made so that the water can touch all pieces of the crop.

When clear water is available, shower type hydro-coolers can be a very economical cooling method for a broad line of products. They are commonly used for corn, celery, avocados, melons, and many products with relatively smooth surfaces. Units can be configured to match harvest needs. They are effective with asparagus, stone fruit and cherries in either boxes or bins. Water cleanup in remote areas can be handled by integrating filtering and sanitation units, with stainless steel on all water contact surfaces adding an additional layer of safety and shelf-life extension. These systems are very useful in line with processing operations. While they are usually integrated with refrigeration components, block ice can also be used to chill the water.

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