Eckert pressure-drop correlation, packed towers

Figure 1337. Corn-elation of flow rates, typical pressure drop behavior, and packing factors of random packed beds. [Eckert, Foote, and Walter, Chem. Eng. Prog. 62(1), 59 (1966) Eckert, Chem. Eng. 14 Apr. 1975)]. (a) Correlation of flow rate and pressure drop in packed towers, (b) Typical pressure drop data 2 in. porcelain intalox saddles, with F = 40, in a bed 30 in. dia by 10 ft high, (c) Packing factors, F, of wet random packings-...

Figure 7-14. Correlation of flow rate and pressure drop in packed towers. Source Eckert [15].

Figure 9-21H. Updated generalized pressure-drop correlation rearranged version of earlier Eckert and Leva, using linear scale for the ordinate and use of capacity factor, Cg. Used by permission of Strigle, R. F., Jr., Packed Tower Design and Applications Random and Structured Packings, 2nd ed. Gulf Publishing Co. p. 21 (1994). Note G = gas, Ib/ft -hr, L = liquid, Ib/ft -hr.

Figure 3.9 Generalized pressure-drop correlation, upper and lower curve limits. (From J. S. Eckert, Design Techniques for Sizing Packed Towers, Chem. Eng. Progress 57(9), 1961. Used by permission of Chemical Engineering Progress.)...

Figure 8.19 The latest version of the GPDC pressure drop correlation, (a) The latest log-log version of Eckert s correlation, as presented by Strigle (15). (Part a from Ralph F. Strigle, Jr Random Packings and Packed Towers. Copyright 1987 by Gulf Publishing Company, Houston, Texas. Used with permission. All rights reserved.)...

FIG. 14-55 Generalized pressure drop correlation of Eckert as modified by Strigle. To convert inches HjO to mm HjO, multiply by 83.31. (From Packed Tower Design and Applications by Ralph E. Strigle, Jr Copyri t 1994 by Gulf Publishing Co., Houston, Texas. Used with permission. All Tights reserved.)... 

The correlation of Eckert (Fig. 13.37) combines a pressure drop relation and safe flow rates insofar as staying away from the flooding point is concerned. A flooding line corresponds to pressure drops in excess of 2 in. water/ft. In use, a pressure drop is selected, and the correlation is applied to find the corresponding mass velocity G from which the tower diameter then is calculated. Another correlation recommended by a manufacturer of packings appears in Figure 13.40. Example 13.16 compares these correlations for a specific case they do not compare any more closely than could be expected from the scatter of flooding data. 

This flow parameter is the square root of the ratio of liquid kinetic energy to gas kinetic energy. The ordinate of this correlation includes the gas flow rate, the gas and liquid densities, the a/e ratio (which is characteristic of the particular tower packing shape and size), and a liquid viscosity term. Lobo et al proposed the use of a packing factor to characterize a particular packing shape and size [17]. They determined that the a/e ratio did not adequately predict packing hydraulic performance. Eckert further modified this correlation and calculated the packing factors from experimentally determined pressure drops [18]. 

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