Heat transfer to Newtonian and non-Newtonian food fluids in plate heat exchangers. Experimental and numerical approaches

The paper first deals with the experimental and theoretical methodology used to study heat processing of non-Newtonian food fluids in continuous plate heat exchangers. The main aspects involved are: (i) the generalization of dimensionless numbers; (ii) correction factors to account for the complex multipass configuration of the exchanger; (iii) determination of the mean temperature at which physical properties have to be computed in empirical correlations. A numerical method is presented with the aim of predicting actual temperature profiles inside each channel of a plate heat exchanger. This method was successfully compared with experimental results of the first part. This method is designed to predict the thermal behaviour of plate heat exchangers when surface fouling or bulk reaction occur.