Improved Correlations for Threshold Flooding and Entrainment in Sieve Trays in Distillation/Absorption Columns

Abstract

The design of tray distillation/absorption columns involves the utilization of tray evaluation procedures. These procedures are based on flooding and entrainment data originally available in graphs (Souders-Brown flooding constant, Csb, and fractional entrainment, ψ). Aiming at using these data for computational applications, several algebraic correlations were proposed in the literature. However, a comparison of the predictions of these correlations and the original data reported by Fair (1961) indicates considerable deviations, which can compromise the accuracy of computational tools that use these expressions. In this article, a new set of parameters is determined for these correlations through reestimation of the correlation parameters using modern optimization techniques and the splitting of the correlation domain in multiple regions. The new set of parameters provides a significant reduction in the prediction errors. To demonstrate the importance of the utilization of the revised set of parameters, a comparison is made of column design results using the original and new parameters. The comparison indicates that the use of low-accuracy options affects the design, which can yield infeasible solutions. The evidence of design problems associated with the correlations is available in the literature, emphasizing the importance of the new set of parameters presented here.