Reflux minimum chart

McCormick [97] presents a correlation for Gilliland s chart relating reflux, minimum reflux, number of stages, and minimum stages for multicomponent distillation. Selecting a multiplier for actual reflux over minimum reflux is important for any design. Depending on the com-... 

The shortcut methods can also be used for approximate analysis of the performance of an existing column. Here, the number of trays, N, is fixed, and the objective is to determine the reflux ratio required to meet a specifled separation. The Fenske and Underwood methods (Equations 12.17, 12.29, and 12.30) are used to calculate the minimum trays and minimum reflux ratio, and R. The operating reflux ratio corresponding to the given number of trays is then read from the Gilliland chart (Figure 12.4). The internal vapor and liquid rates are calculated from the reflux ratio and product rates. A check must be made to determine if the existing column can handle the calculated vapor and liquid traffic. 

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