NEW CORRELATIONS FOR HEAT-TRANSFER COEFFICIENTS DURING DIRECT COOLINGOF PRODUCTS

An analytical method for determining the heat transfer coefficients of food products being cooled in water and in air flows is presented. Fo od products are idealized as geometrical solid objects of regular shap es. New correlations between heat transfer coefficients and cooling co efficients are developed in simple forms for practical use in the refr igeration industry. These correlations are then used to determine the heal transfer coefficient for a cylindrical carrot cooled in air flow as an illustrative example. In addition, evaluating the heat transfer coefficients for several products using the available experimental coo ling coefficient values from the literature, two new correlations betw een the heat transfer coefficient and the cooling coefficient are also obtained for water and air cooling applications. The results show tha t the correlations presented in this article can determine the heat tr ansfer coefficients of food products during forced-convection cooling in a simple and accurate manner.