Pressure-drop correlations tray columns

Bennett, D. L., Agrawal, R., and Cook, P. J., New Pressure Drop Correlation for Sieve Tray Distillation Columns, AIChE J, 29, 434-442 (1983). 

BEN 83] Benett D.L., Agrawal R., Cook P.J., New pressure drop correlation for sieve tray distillation columns , American Institute of Chemical Engineers, vol. 3, p. 434, 1983. 

Column trays come in many different types, but they all share certain features that may be described by means of a general, simplified model. Model simplification is essential in the study of tray hydraulics even when discussing one particular type of tray. The reason for this is the highly complex nature of countercurrent, two-phase fluid flow in the column and across the trays. Certain assumptions must be made in the development of flow and pressure drop correlations. 

The pressure drop over sieve and valve trays may be estimated using correlations presented by Lockett (1986) and Kister (1992). For bubble cap trays the procedures described by Bolles (1963) can be adapted for computer based calculation. Kister (1992) reviews the methods available for estimating the pressure drop in dumped packed columns. The pressure drop in structured packed columns may be estimated using the method of Bravo et al. (1986). 

Many of the correlations presented here are of general applicability although some may be particularly suited for certain tray types as indicated. The main objectives are to determine the tray or column diameter for a given application, to calculate the tray liquid holdup and the pressure drop between the trays, and to check for flooding (entrainment and downcomer) and weeping. 

In the development of the above series of equations, Zuiderweg has used the work of many prior investigators and relied heavily on the data recently released by Fractionation Research, Inc. (iHki), as repotted by Sakata and Yanagi on the performance of two types of commercial perforated tray. Zuiderweg also presents correlations that define the flow regime transitions, pressure drop, entrainment, column capacity, and other operating panameiers of sieve trays. 

Drop Correlation" for packed columns, based on observed pressure drop dafa. The percentage of flood for valve trays is calculated from standard industry correlations as based on the observed flows listed in Table 8-1. ... 

---