Abstract: In design of reactors, it is assumed that no backmixing occurs or that the system is well mixed and uniform in composition. A mathematical analysis of complete backmix and nonbackmix reactors is given. Partial backmix reactors for liquid systems have a larger 'local dispersion no.' than do reactors for gas systems. Backmixing with 1st- and 2nd-order reactions are treated mathematically. Heat effects depend on the surface-volume ratio of the reactor, so difficulty may be encountered in scale-up from experimental to plant equipment. Care must be taken in extrapolating backmixing data from small to large equipment.

Abstract: Charts which were based on the assumption that longitudinal fluid mixing is analogous to the process of diffusion were constructed by using data from literature. These data, which were obtained under widely varying conditions, fell in a narrow band in the turbulent region. However, the charts have only limited application in the streamline region. The diffusion model is based on the use of a straight pipe, which most of the data used did not satisfy. Pipe roughness and curvature have been shown to increase mixing. Further experimentation was recommended for the streamline region, to narrow the range of uncertainty in the curves used in the turbulent region, and to determination the role of the Schmidt number at low Reynolds numbers.