Mathematic models of freezing pellets of foodstuffs
1984
Kurtanjek, Z. | Spehar, B. (Prehrambeno tehnoloski fakultet, Zagreb (Yugoslavia))
The applied numerical collocation process and derived computer program enables the successful calculation of heat transmission for food staff freezing in pelleted shape and in direct contact with freezing medium. The time of transformation water into ice is determined under the supposition of quasi stationary condition. The resistance heat transmission estimate is based on Biot's number determination in external, highest layer and the layer formed between liquid and stiff phase, and at resistances of heat transmission through 2 phases. The heat transmission dynamics is based on calculation the own matrix value of 2nd rank, gotten from polynomal approximation for partial, differential equation of heat transmission. Comparison of theoretical results with measures of experimentation proves the importance of coefficient of heat transmission determination in freezers, and problem of thermal characteristics estimation of chemical structure of basic components of products. The determination of effective coefficient of heat diffusion because of freezing medium penetration into specimen is important
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