Internal interconnections in TMP processes

The casing pressure dynamics of a thermomechanical wood-chip refiner are studied in this paper. Interest focuses on the internal interconnections, which can cause oscillations in the process. Linear dynamics are considered when analysing the interconnected process from a process control perspective. Control strategies are discussed and a grey-box model for parameter estimation is derived and compared with standard black-box models. The grey-box models are shown to reflect the effects of time-delayed internal interconnection more efficiently than black-box models.