Combined Models for Macroscopic Flow Phenomena

Most of these models involve exponential functions in their F t) responses as shown in the table, so tests of their possible application in interpretation of F t) data are conveniently carried out via simple log-linear plots of the response data. If linearity is attained, the model parameters are readily evaluated. 

Obviously, many such combinations can be assembled and the intelligent application of a given combined model to interpretation of nonideal flows in a particular reactor must rely on additional information concerning geometric properties such as stirrer placement, feed inlet and product withdrawal placement, corners or internal structural elements leading to dead volumes, and so on. A certain amount of intuition is also a useful commodity in each modeling.  

This expression applies for either PFR-CSTR or CSTR-PFR sequence. 

CSTR with short-circuiting and dead volume  

More complex versions of these combination models have been proposed by various researchers [D. Wolf and W. Reanick, Ind. Eng. Chem. Eundls., 2, 287 (1962) J.G. van de Vusse, Chem. Eng. Sci., 17, 507 (1962)] B.A. Bulfham and L.G. Gibilarco, Amer. Inst. Chem. Engr. JL, 14, 805 (1968)]. These have been shown to be useful in a number of practical applications in extension of the ideas above. 

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