Several factors related to the proper shipping of fresh seafood by airplane were studied in this thesis. These included precooling, gel pack effectiveness, external temperatures encountered by shipping containers, and coolant placement in a shipping container.
Experiments were conducted to determine cooling times of 10 and 20 pound boxes and 10 pound bags of whole fish. The ”10-pound” box was then modelled using finite element techniques. The model was found to accurately predict the temperature response of the box for a constant temperature boundary condition. Different boundary conditions were applied to the model. These were: constant temperature (such as an ice-slurry); low, medium and high velocity air (such as in a commercial refrigerator). The model was then used to predict cooling times for the other boundary conditions.
The enthalpy needed to thaw the contents of different gel packs was measured and compared to that of ice. None of the gel packs had as high an enthalpy as ice. In addition, the warming characteristics of the gel packs with the highest enthalpy was compared to those of ice. It was found that the warming characteristics of the gel pack appeared to be similar to that of ice.
The actual shipment of seafood to distant markets was studied by sending a data logger with several shipments to the west coast and collecting temperature data every 5 minutes during these shipments. Temperatures in 12 different locations were measured. Of particular interest were the outside temperatures which were later used in the modeling of the shipments. The shipments were sent in EQ containers. The containers experienced a wide range of temperatures.
A finite element model was developed to predict the temperature of seafood under simulated transport conditions. Two boundary conditions were applied to the model; these were still air at 30°C and the approximate temperatures encountered during one of the shipments. Three different arrangements of coolant placement were studied. These were all ice on top of the product, half the ice on top and half in a layer in the middle of the product, and half of the ice on top of the product and half of the ice below the product. The latter arrangement provided the most uniform temperature distribution of the three through 18 hours of simulation. It was also found that shipments should be delivered in less than 24 hours for the amount of coolant used. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/42216 |
| Date | 25 April 2009 |
| Creators | Stringer, Lawrence Jeffrey |
| Contributors | Agricultural Engineering |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | xiii, 124 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 22839503, LD5655.V855_1990.S7655.pdf |
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