(58d) Pressure Drop of Packed Column Internals

Because of their low pressure drop per theoretical stage random and particularly structured packings are frequently used in vacuum applications. For applications requiring operation at absolute pressures bellow 100 mbar usually total allowable pressure drop is specified. Demanding separations require frequent collection and redistribution of liquid, and this means dealing with a source of pressure drop which cannot be ignored as it is usually done, taking into account the pressure drop of the irrigated packed bed only. Unfortunately only scarce data on the pressure drop of liquid and vapor redistribution sections can be found in open literature. The purpose of this paper is to summarize available pressure drop data for most common types of liquid collectors and distributors and to evaluate and discuss them in a systematic way in terms of overall pressure loss coefficient which could provide a practical guidance to people dealing with design and rating of packed columns. Main body of experimental data evaluated in this study has been obtained using 1.4 m internal diameter column hydraulics' simulator available at the Delft University of Technology.