02 Dec Improving Quality Through Cold Air Flow Within A Reefer Container
This article introducing the benefits of RAFT kits, written by our own Barry Hugo, initially appeared in Fresh Plaza magazine.
RAFT Kits For Fresh Produce Transportation
“Cold air is lazy, it takes the path of least resistance,” explains Barry Hugo, Managing Director at Dunlash South Africa and Refrigerated Air Flow Technologies (RAFT). This is problematic in refrigerated containers as often the chilled air short-circuits and does not keep the fresh produce at the desired temperature. This challenge lead to the reasoning behind their new, redesigned RAFT kit that fits into any 40ft reefer container. This kit forces the chilled air to follow a more horizontal path, through the pallets. This is achieved by covering part of the container floor with a floor liner and blocking the air space above and below the pallets.
As the chilled air is now delivered through a smaller surface area and not over the top of the load, the velocity of air increases, resulting in improved penetration through the entire load and thus better management of fruit pulp temperature.
Trials on stone fruit and citrus in containers packed with their RAFT kit, compared to control containers on the same voyage, have shown that their system is able to reduce the temperature difference within the load by 1.5°C to 2°C, with a direct impact on quality on arrival.
The temperature remains more even from the front to the back of the container when cold air flow is forced through the pallets. The RAFT kit has been patented in South Africa and internationally.
Costing ZAR960 (US$60) per container, the RAFT kit will provide significantly more added value than its cost through better temperature management, either on its own in a reefer or as a complementary system to containers equipped with CA, MA, or Ozone Generation.
Cardboard Baffles Replace Inflatable Dunnage Bags In New Design
Instead of inflatable dunnage bags, requiring a compressor, the new design makes use of specially designed cardboard baffles placed between the top of the pallets in the container and the roof. In addition, baffles are placed at the pallet bases themselves. These baffles block off the cold air’s preferred shortcut and force virtually all of the cold air through the pallets of fruit themselves.
“The results we’ve obtained from our trials on citrus and plums were very good, there is a definite advantage to the kit.”
A temperature-sensitive commodity like table grapes would find benefit from using their system.
International manufacturing and marketing agreements are available for select countries.