Flooding in packed columns

A full discussion of flooding in packed columns is given in Volume 2, Chapter 4. 

H. Krehenwinkel and H. Knapp, Pressure drop and flooding in packed columns operating at high pressures, Chem. Eng. Technol., 10 (1987) 231-242. 

FIG. 15-36 Crawford-Wilke correlation for flooding in packed columns. Use only the units given in the text. [Reprinted from Crawford and Wilke, Chem. Eng. Prog., 47(8), pp. 423-431 (1951), with permission.]... 

Flooding in packed columns can be discussed with reference to a typical pressure drop characteristics diagram (Fig. 14.3). 

Mersmann s [3] flooding point diagram describes the flooding in packed columns for small packing elements with d < 25 mm sufficiently accurately throughout the entire... 

Ma6kowiak J. Determinition of flooding gasvelocity and liquid hold-up at flooding in packed columns for gas/liquid-systems. Chem. Eng. Tech. 13 (1991) p. 184-196... 

For total-reflux distillations carried out in packed columns, regions of loading and flooding are identified by their effects on mass-transfer efficiency, as shown in Fig. 14-47. Gas and liquid rate increase... 

SAWISTOWSKI, H. Chem. Eng. Sci. 6 (1957) 138. Flooding velocities in packed columns operating at reduced pressures. 

Sherwood TK, Shipley GH, Holloway FAL. Flooding velocities in packed columns. Ind Eng Chem 1938 30 768. 

Flooding velocities in packed columns. Trans. Am. Inst. Chem. Engrs., 40 29-49. 

Flooding velocities in packed columns can be estimated from Fig, 20.7. In this figure the abscissa is the group... 

Generalized correlation for flooding and pressure drop in packed columns. After Eckert )... 

The term lower limiting velocity is used to denote the vapour velocit - (referred to unit cross section of the empty column) below which the effectiveness of the column begins to fall off, the term upper limiting velocity for the vapour velocitj at which flooding is so intense that, in plate columns, the layer of liquid on a j)late is entrained upwards, and in packed columns a quantity of spraying liquid rises from the foot of the column to the top. Since the fundamental publications by Mach [219],... 

Excessive column pressure drop. In general, a pressure drop per tray greater than 50 to 60 percent of the tray spacing in the relevant column section indicates flooding (2, 186, 231). In packed columns, the following rules of thumb are useful. 

In packed columns, defining the flood point by use of a pressure drop... 

Similar guidelines apply when column capacity restriction is primarily related to column vapor load [e.g., a downcomer backup restriction when backup is primarily due to dry tray pressure drop (199) or in packed columns in which flooding is induced by excessive vapor loads (195)]. The guidelines do not apply when column capacity restriction is primarily caused by excessive liquid load (e.g., downcomer choke or downcomer backup restriction when the backup is primarily... 

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