Applications of modelling to optimise ultra high temperature milk heat exchangers with respect to fouling

A model for indirect thermal treatment of milk was implemented and applied to three commercial heat exchanger systems: two systems using tubular heat exchangers, albeit very different ones, and a plate type heat exchanger system. The model emphasis was placed on fouling prediction and bacterial inactivation, but other heat induced reactions were also included. The model was able to reproduce the time-temperature profiles satisfactory in all three cases. Some optimisation strategies with respect to fouling minimisation were simulated. For all cases, it was not possible to obtain major improvements using only the available degrees of freedom. However, the model predictions indicate that significant reductions in fouling are possible when applying minor redesigning to the systems. Especially the location of a preholding section proves to be of major importance. (C) 2003 Elsevier Ltd. All rights reserved