THEORY AND PRACTICE IN MODELING PAPER-MACHINE WHITE WATER-SYSTEMS

Some of the ways in which models can be constructed and analysed are discussed with particular reference to paper machine white water systems. Such systems can be thought of as sequences of recycle flow networks, consisting of pipes and containers. For real paper machines, all such containers may be considered as completely mixed. A flow network can be described as a set of internal and external age distributions. For the purposes of modelling, such a network may be presented in various ways: as residence time distributions; as discrete time Markov processes; or as computer based interactive models. The paper shows how each of these techniques was used to model a pilot paper machine. The paper details the construction of a theoretical model, with the above formulation techniques compared. Results obtained from the models are compared with actual data measured on a pilot paper machine.