Mathematical Modelling of Heat Exchanger Fouling by a Whey Protein - Limitations and Promise
by
X. D. Chen
University of Auckland
Coauthors: J. Chen

Fouling of heat exchangers is an undesirable phenomenon, resulting in a reduced heat transfer efficiency and increased pressure drop. In the food industry, fouling deposit can also act as sites to support bacteria, causing product safety concerns. When fouling becomes substantial, cleaning needs to be carried out, which takes similar amount of time as that of the normal production. Fouling in the food industry is therefore a significant economic factor. Fouling minimisation requires scientific considerations in design and also in deciding operational conditions (temperature, fluid flow rate and chemical composition). Such considerations would no doubt involve the interactions between the compositional changes as well as the effect of fluid motion. The process is very complex and is difficult to model. However, without a comprehensive modelling of the process, which can be backed up by practical observations, optimisation of the design and operational conditions is not possible or at least, would not be realistic. There are many intrinsic issues that can not be observed when many assumptions are made in order to simply the mathematics involved. The current study employed a model, originally developed at Cambridge University , to reproduce some of the previous results and then, a significant upgrade was made due to the addition of a more realistic reaction mechanism and better boundary layer flow approximation. The model describes the momentum, energy and mass transfer processes involved in fouling together with the protein denaturation-aggregation kinetics. In particular, the reversible reaction step is now incorporated so the process of fouling in a cooler section can now be modelled more realistically. The model has been compared with the published experimental data and some interesting observations have been made on the model predictions. The limitations and promise of the model have been discussed.

Date received: November 3, 1999

Copyright © 1999 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cadl-26.