Prediction of the freezing characteristics of spherical-shaped food products

An analysis of the freezing characteristics of spherical shaped food products with time dependent surface-temperature variation is presented. The one dimensional heat conduction equations in spherical coordinates for the frozen and unfrozen regions are solved simultaneously by a suitable transformation to obtain an equivalent slab. Goodman's integral method is applied to obtain the solution in terms of four dimensionless parameters. The results are presented for an exponential variation of the surface temperature for parameter values covering the ranges of the thermophysical properties and processing conditions encountered in food freezing practice. A correlation for facilitating the estimation of the freezing time is also given. © 1978.