Modeling techniques for the control of thermal exchangesin mixed continuous-discontinuous flow food plants

In food processing plants chemical, microbiological, organoleptic properties of products are modified with kinetics that typically depend on the time-temperature (tT) profile assumed by the product during the process. This profile can be profitably used for quality control and could be even employed for process control. While tT-profile distributions have been determined in continuous-flow processes no results are available so far for plants where a mixed continuous-discontinuous flow condition occurs. This is, for example, the case of plants that present accumulation points as well as valves and pumps that switch on and off the product flow in the pipes. In this paper a new modelling framework, based on the use of compartmental models, is presented. This model structure allows the derivation of the tT-profile of any portion of the food product while it is processed.