Fruit Cooling

Requirement:

Cool on the same day as picked from the orchard, hundreds of crates of fruit from the field temperature (core at perhaps 95 degrees) to as close as 33 degrees storage temperature as possible prior to passage to the storage rooms.

This requires a hydro-cooling system that will deliver large quantities of recirculated water at 33 degrees that can be flooded over the warm fruit on a conveyor belt that accepts fruit from the field and delivers it to the storage rooms.

During this flooding process, the water collects fruit residue (leaves, stems,dust) that must be settled from the return water before it is again cooled and delivered to the fruit flooding process.

The entire water system is subjected to corrosion forces from variable pH and oxidation and therefore must be corrosion resistant without consequentially affecting the heat transfer capability.

The fact that the fruit is edible means that the refrigerant must be non toxic when ingested and harmless to the atmosphere if leaked.

Solution:

A system of Air Cooled USP Grade Propylene Glycol chillers in conjunction with a flooding system over stainless steel bare tube cooling coils, bronze fitted pumps and a cleanable settling tank has been designed. A requisite of the system is that it be totally compatible with and cross connected with the room storage system to offer redundancy to both.

5/3/99

Kenneth W. Wicks

ASHRAE Fellow