PIGFORD

M. Benedict, T. Pigford, and H. Levi, Nuclear Chemical Engineering, 2nd ed., McGraw-HiU Book Co., New York, 1981, Chapt. 14. 

Sherwood, Pigford, and Wilke, Mass Transfer, McGraw-Hill, 1975. Shulman, Ullrich, Proulx, and Zimmerman, AJChE J., 1, 253 (1955). Shulman and Margolis, AJChE J., 3, 157 (1957). 

For laminar flow in vertical tubes a series of charts developed by Pigford [Chem. Eng. Prog. Symp. Sen 17, 51, 79 (1955)] maybe used to predict values of... 

D. Rectification in vertical wetted wall column with turbulent vapor flow, Johnstone and Pigford correlation =0.0.328(Wi) Wi P>vP 3000 < NL < 40,000, 0.5 < Ns. < 3 N=, v,.gi = gas velocity relative to R. liquid film = — in film -1 2 " [E] Use logarithmic mean driving force at two ends of column. Based on four systems with gas-side resistance only, = logarithmic mean partial pressure of nondiffusing species B in binary mixture. p = total pressure Modified form is used for structured packings (See Table 5-28-H). 

FIG. 14-5 Nnmher of overall gas-phase mass-transfer units in a packed absorption tower for constant mGf /LM solution of Eq. (14-23). (From Sherwood and Pigford, Absorption and Extraction, McGraw-Hill, New York, 1952. )... 

Estimation of for Irreversible Reactions Figure 14-14 illustrates the influence of either first- or second-order irreversible chemical reactions on the mass-transfer coefficient /cl as developed by Van Krevelen and Hoftyzer [Rec. Trav. Chim., 67, 563 (1948)] and as later refined by Periy and Pigford and by Brian et al. [Am. Inst. Chem. Eng. /., 7, 226(1961)]. 

Estimation of fct for Reversible Reactions When the reaction is of the form A B, where B is a nonvolatile product and the equilibrium constant is defined by Cg = K Ca, the expressions for computing /cl become extremely complex. A good discussion of this situation is given in Mass Tran.sfer by Sherwood, Pigford, and Wilke (McGraw-Hill, New York, 1975, p. 317). Three limiting cases are hsted below ... 

FIG. 14-61 Liq uid distribution in a 6-in column packed with 1/4-in broken-stone packing. Increments of radius represent equal-annual-area segments of tower cross section. Central-point inlet. Water rate = 500 lb/(b-fr). Air rate = 810 lb/(b-ft ). To convert pounds per bour-square foot to kilograms per second-square meter, multiply by 0.00L356 to convert inches to centimeters, multiply by 2.54. (Data from Baker, Chilton, and Vernon, in Shetxuood and Pigford, Absorption and Extraction, 2d ed., McGraw-Hill, New York, 1952. )... 

A comparison of experimental data for carbon dioxide absorption obtained oy Hatta anci Katori (op. cit.), Grimley [Trans. Inst. Chem. Eng., 23, 228 (1945)], and Vyazov [Zh. Tekh. Fiz. (U.S.S.R.), 10, 1519 (1940)] and for absorption or oxygen and hydrogen by Hodgson (S. M. thesis, Massachusetts Institute of Technology, 1949), Henley (B.S. thesis. University of Delaware, 1949), Miller (B.S. thesis. University of Delaware, 1949), and Richards (B.S. thesis. University of Delaware, 1950) was made by Shei wood and Pigford (Absorption and Extraction, McGraw-Hill, New York, 1952) and is indicated in Fig. 14-78. 

SOURCE From Sherwood, Pigford, and Wilke, Mass Transfer] McGraw-Hill, 1975, p. 305. 

Sherwood, T. K., Pigford, R. L., and Wilke, C. R., Mass Transfer. McGraw-Hill, New York, 1 975. Sissom, L. E., and Pitts, D. R., Elements of Transport Phenomena. McGraw-Hill New York, 1972. Treybal, R. E., Mass Transfer Operations. McGraw-Hill, New York, 1968. 

Pigford, R. L. (1976). Chemical Technology The Past 100 Years. Chemical and Engineering News (April 6) 190-195. 

Data on heats of solution of ammonia taken from International Critical Tables Vol. V, pg. 213 [35] by Sherwood and Pigford Absorption and Extraction, pg. 161, 2nd Ed., McGraw Hill Book Co., Inc.) Ref. 63. ... 

Bergelin, O. P, W. L. Lafferty,Jr., M. D. Leighton, R. L. Pigford, Heat Transfer and Pressure Drop during Viscous and Turbulent How across Baffled and UnbafUed Tube Banks, University of Delaware, Eng. Exp. Sta., Newark, Del. Bui. No. 4 (1958). 

Emmert and Pigford (E2) have studied the reaction between carbon dioxide and aqueous solutions of monoethanolamine (MEA) and report that the reaction rate constant is 5400 liter/mole sec at 25°C. If it is assumed that MEA is present in excess, the reaction may be treated as pseudo first-order. This pseudo first-order reaction has been recently used by Johnson et al. (J4) to study the rate of absorption from single carbon dioxide bubbles under forced convection conditions, and the results were compared with their theoretical model. 

Such effects are described in more detail by Sherwood, Pigford and Wilke(271. 

Sherwood and Pigford(7) have shown that if the data of Gilliland and SHERWOOD<36) and others 35 38,395 are plotted with the Schmidt group raised to this power of 0.67. as shown in Figure 10.14, a reasonably good correlation is obtained. Although the points are rather more scattered than with heat transfer, it is reasonable to assume that both jd and 7/, are approximately equal to 0. Equations 10.224 and 10.226 apply in the absence of ripples which can be responsible for a very much increased rate of mass transfer. The constant of 0.023 in the equations will then have a higher value. 

SHERWOOD and Pigford(7) found that the effect of the Schmidt group was also influenced by the Reynolds group and that the available data were, fairly well correlated as shown in Figure 10.16, in which (hod )/D is plotted against Re Sc0-67. 

Sherwood, T.K. and Pigford, R.L. Absorption and Extraction (McGraw-Hill, New York, 1952). 

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