Conventional, Continuous Hydro Cooling
Continuous hydro cooling is the preferred method to pre-cool produce. Continuous hydro cooling moves produce on a conveyor belt through the water discharge chamber. Conventional hydro coolers chill raw unpacked produce, or bundled bins of produce on a conveyor belt. The produce enters one end of the machine on a conveyor belt. It then moves into a cooling chamber, where a reservoir sits under the conveyor belt. Ice can be used in the reservoir with water sprayers, or an air pump can cool the sprayers. Once the water is sprayed the reservoir “catches” the water and it is recycled. The conveyor belt moves about 1 foot per minute, but can be adjusted dependent upon the produce.
Construction of conventional continuous hydro coolers are built to large scale. A hydro cooler, quoted with a 10 foot chamber, will have a conveyor belt measuring 20 feet. The longer the cooling chamber, the more efficient the machine is. One of the largest hydro coolers contains a 50 by 8 foot reservoir for active cooling. Designers must consider conveyor speed, conveyor width, water temperature, flow rate, and crop type when constructing hydro coolers. Water flow rates range anywhere from 20 gallons a minute to 1,600 gallons per minute.