Modelling and identification of a high temperature short time pasteurization process including delays

In this paper, an improved mathematical model for a High Temperature Short Time (HTST) pasteurization plant is proposed. The main differences from previous models are that the four interconnected blocks of the heat exchanger model are assumed to be of third order; therefore fundamental physical properties of the plant are not neglected. In addition, time delays at the output of the heat exchangers are considered in order to take into account the fact by which the temperature sensor is not physically within the heat exchanger. Following the proposed model, a parameter identification procedure is suggested, by using stable filtering for the input and output signals.