computer simulation program for evaluation of the continuous heat treatment of particulate food products. 2. Utilisation
Skjoldebrand, C. | Ohlsson, T.
A computer program for calculation of temperatures in a liquid containing particles during continuous heat treatment has been developed at the SIK. The program facilitates the study of the influence of processing on product quality in an aseptic processing system. The calculated F value is related to the safety, and the cook value (C value) is related to the quality of the product. In this paper, results of some calculations using the program are presented. They concentrate on the influence of the processing conditions on the process design. These results indicate that factors such as particle heat transfer coefficient, both in the holding tube and in the scraped surface heat exchangers (SSHEs), flow conditions, particle diameter and sterilisation temperature have consequences for the holding tube length, i.e. the processing time, for a given lethality. For example, for small particle heat transfer coefficients (< 100 W m2 K), a small change will have a large effect on the required processing time (i.e. the holding tube length). However, at particle heat transfer coefficients > 150-200 W m2 K a small change does not greatly affect the processing time (i.e. holding tube length). The program can thus be used to examine whether the surface heat transfer coefficient is the rate-limiting factor, or whether the heat conduction inside the particles is more important in the design of the process.Show more [+] Less [-]