A FORMAL GRAPHICAL BASED PROCESS MODELING METHODOLOGY

In this paper we present a representation scheme for chemical unit pro cesses. The representation is based on a topological and a phenomenolo gical abstraction of the process. The topological abstraction decompos es the process into control volumes and boundaries. The phenomenologic al abstraction represents the phenomena in the process using three gen eral process characteristics, i.e. transport, reaction/generation and accumulation of mass and energy. For these entities we define a consis tent set of graphical symbols that will be connected together in a net work according to the modelers understanding of the process, giving a representation of the process. We further suggest to employ this repre sentation in the development of a modeling methodology, where the symb ols are related to differential and algebraic equations in order to re present a complete and consistent mathematical model. The methodology is successfully applied to two industrial processes, a ferromanganese furnace and an aluminum electrolysis cell. The latter will be used as an example. Simulations of the aluminum cell focusing on AlF3 dynamics are included.