Liquid hold-up and scale change in distillation.

Data of static and operative hold-up are determined by distillation at total reflux in a structured gauze packing column of the mixture cyclohexane- methyl benzoate and ethanol-methyl benzoate. Dependence of hold-up on F-factor has the same shape as variations suggested by severals correlations for pilot scale and similar equations are proposed. As a result of this dependence and the relationship between hold-up and effective area, this one may be considered a constant when flow increases and the change in the efficiency of laboratory packings can be explained.