Experimental Determination of Fluid-particle Convective Heat Transfer in Particulate Food Processing

G. Dall'Aglio, L. Palmieri, D. Cacace, G. Dipollina

Stazione Sperimentale per l'Industria delle Conserve Alimentari, Viale Tanara 31/a, 43100 Parma (Italia) 

Article history:
Received June 15, 1994
Accepted September 26, 1994

Summary:
The design of continuous sterilization of particulate foods is limited by the impossiblity of monitoring particle temperature during the continuous process, by the difficulty of solving the differential equations of conductive heat transfer within the particles and, finally, by the uncertainty in estimating the convective heat transfer coefficient between fluid and particle. In this work, the differential equations for heat transfer are solved by means of a numerical method based on a finite difference discretization scheme. The heat transfer coefficient is estimated using an experimental set-up consisting of a cubic tomato particle immobilized in a tubular pilot plant. Particle temperatures of heated tomato juice at different flow rates and concentration are measured by means of thermocouples and calculated using the numerical method: a best fitting procedure between experimental and calculated data gives then the optimal coefficient values.