In the summer project Temperature control in container transport of fresh fish products, which was carried out in collaboration between Eimskip and Matís, the heat distribution in refrigerated containers was measured and the procedure for loading refrigerated and frozen containers, which are used for both the transport of fresh and frozen goods, was taken out.
The temperature control examined in the project concerns the storage and transport of fresh fish, but it is much more sensitive to temperature fluctuations than frozen products. It is therefore important that the ambient temperature of the products in the container is well controlled throughout the transport process. Results of the European project Chill on and the AVS project Simulation of cooling processes show that well-controlled sea transport can achieve a much longer shelf life for marine products than is available in less temperature-controlled air transport chains.
The results of the measurements showed that the heat distribution within the containers is dependent on the loading procedure, as the air flow in the container varies according to the loading pattern. Heat distribution in containers is not homogeneous and is generally colder at the bottom and closer to the cooling machine than hotter at the air of the container and next to the door. Measurements also showed that the temperature inside the container fluctuates with the ambient temperature when it is hot outside. It should be noted that the measurements were made during the summer.
Cooling containers are designed to maintain low air and product temperatures within the container but not to cool products. The results of the measurements showed the importance of pre-cooling a product for loading into containers, but if it is loaded too hot, it takes a long time to reach the ideal storage temperature. The project examined different container types with the aim of identifying which container type is best suited for transporting fresh fish, where a low and stable temperature is important. A correlation could be made between the performance of different containers and their age.
Cooling process simulation is also funded by the Rannís Technology Development Fund (TÞS) and the University of Iceland Research Fund.
For further information Björn Margeirsson.