Overall Efficiency Evaluation of Commercial Distillation Coumn with Two-Pass Valve Trays

This article addresses the prediction of the efficiency of two-pass crossflow valve trays in an industrial distillation column using different models with and without the use of the Stagnant Regions Model, as proposed by Lockett in 1986. Contradicting what could be expected, few papers have been published about the main characteristics of valve trays and about efficiency of two-pass valve trays. The results suggest that O'Connell's correlation, the model of Chan and Fair applied to two-pass valve trays converted to one-pass valve trays and the model of Chan and Fair with the SRM method are those that best predict the efficiency of this two-pass crossflow valve trays column. The O'Connell’s correlation underestimates the efficiency, showing a slightly conservative value, while the predictions using Chan and Fair model and the modified Chan and Fair model with equivalent length proposed by Klemola and Ilme overestimate the efficiency, showing slightly non-conservative results