Simultaneous Determination of Thermal Diffusivity and Heat Transfer Coefficient during Sterilization of Carrot Dices in a Packed Bed

Abstract

ABSTRACTCarrot dices were heated under ultra‐high temperature sterilization conditions in a packed bed to quantify the effect of superficial fluid velocities on heat transfer coefficient (h) and obtain a value for thermal diffusivity (α). h and α were determined simultaneously under non‐constant heating fluid temperatures using a finite difference technique. Temperature profiles calculated using assumed h and α were matched with measured temperature at two points in a cube. Using best fit value for α of 1.94 × 10−7 m2/sec, mean h ranged from 600 to 1533 and 359 to 735 W/m2K for 0 and 1.58 cm/sec fluid velocity and 1 and 2 cm cubes, respectively. At 15.2 cm/sec, when a controlled heat transfer, calculated α was 1.86 ± 0.044 × 10−7 m2/sec.