Note. Overall Heat Transfer Coefficient to Canned Liquid During End-over-end Sterilisation

Abstract

The overall heat transfer coefficient as a function of rotation speed (5–20rpm) was calculated for cans containing a 2% NaCl and 1.5% sucrose aqueous solution during end-over-end heat sterilisation at 120°C. The values obtained for the overall heat transfer coefficient, U (W/m2 °C), were: 544.4±85.3 at 5rpm, 710.7±24.5 at 10rpm, 760.5±17.7 at 15rpm and 941.6±22.1 at 20rpm. A correlation was developed in terms of Nusselt, rotational Reynolds and Prandtl numbers to predict U(Nu = 1.866Re0.379 Pr0.38). The characteristic dimension in Nu and Re was the diameter of the can. This correlation (R2 = 0.88) was valid for Re within the range of 3,012–14,820 and Pr within 2.02–2.63 values.