A strategy is presented for planning operating procedures for continuous chemical processes. The theory of operating procedure synthesis is based in part on research in problem solving done by workers in the fields of cognitive psychology and artificial intelligence, and was developed by analysis of industrial operating manuals. This methodology for operating procedure synthesis includes: (1) A system decomposition method which exploits the existence of stationary states, or steady states in which the operating goals are partially met. Stationary states are used as islands, or target states to efficiently organize the search for procedures. (2) A modified form of means-ends analysis, by which operating goals are identified and operators (process manipulations) are sought to satisfy the goals. (3) A constraint-guided search strategy, which seeks to form sequences of operators which are feasible with respect to operating constraints. (4) Hierarchical planning, in which procedures are progressively specified from general plans down to determining valve and set point operations. (5) A hierarchy of modelling techniques, including functional modelling, which is based on the behavior of units as sources and sinks of physical quantities, local causal models, and numerical models. (6) Formalization of the synthesis of operating procedures for purging chemical processing systems. Techniques are introduced for identifying chemical species to be purged, choosing methods and auxiliary fluids for executing purge tasks, and allocating chemical species to their final destinations. A least-commitment strategy is proposed for generating and sequencing purge operators.; Some of these techniques are implemented in a computer program, the Prototype Operating Procedure Synthesis Program (POPS). The procedure synthesis methodology is illustrated with two example startup problems--the purging and startup of a chloroform reaction system and the startup of a heat recovery network.
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