Coefficients dʹéchanges superficiels pour la réfrigération et la congélation dʹaliments immergés dans un coulis de glace

Ice slurries are mixtures of microcrystals of ice in aqueous solutions that do not freeze under the operating conditions used. One potential application of ice slurries in the food industry is the chilling and freezing of foods using direct contact. The latent heat of melting of the ice makes it possible to improve the superficial coefficients of exchange with respect to those obtained using conventional single-phase fluids. In this study, the authors compared the coefficients obtained using immersion in a copper cylinder (l=0.03 m, D=0.02 m) in various single-phase media (brines) with those obtained using ice slurries. They also analysed the influence of the ice mass fraction, stirring, the evolution of coefficients over time, and the relationships between dimensionless numbers (Nu, Re and Pr).