Analytical studies of the rapid cooling process blanched vegetable products nitrogen gas

DOI: 10.21047/1606-4313-2017-16-3-53-61
UDC 621.56/.59; 664.8.036.2

Analytical studies of the rapid cooling process blanched vegetable products nitrogen gas

Venger K. P., Popkov V.I., Feskov O. A.

For citation: Venger K.P., Popkov V.I., Feskov O.A. Analytical studies of the rapid cooling process blanched vegetable products nitrogen gas. Vestnik Mezhdunarodnoi akademii kholoda. 2017. No 3. p. 53-61

Abstract
The article deals with auniversal mathematical model for calculating the length of blanched vegetable products’ rapid cooling with nitrogen gas. The model takes into account two stages of movement of temperature fronts in the product and allows to consider symmetric or asymmetric heat transfer conditions. Novel final equations for calculating the duration of the cooling and final temperature in the thermal center of the product are obtained. An equation for determining the initial temperature of the product in the case when, after blanching and before cooling, the product remains outdoors for some time and is cooled under natural convection.A method of calculating heat transfer coefficient is proposed and its results are obtained in the form of table values and graphic dependences. The influence degree of the product thickness, temperature, and nitrogen circulation rate on the coefficient is shown.Cooling duration, taking into account the two variants of heat transfer conditions presented by their graphic dependences on the wide range of key process parameters (product thickness, the temperature and circulation rate of nitrogen gas, the exhaust temperature of cooling agent vapor) is calculated. The results of the these parameters’ effect on the cooling duration are assessed.

Keywords: mathematical model, snap-chilling, gaseous nitrogen, vegetable products, blanched.


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