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Performance of packed columns. I. Total, static, and operating holdups
Author(s) -
Shulman H. L.,
Ullrich C. F.,
Wells N.
Publication year - 1955
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690010219
Subject(s) - raschig ring , vaporization , mass transfer , chemistry , absorption (acoustics) , mechanics , volumetric flow rate , ceramic , packed bed , chromatography , analytical chemistry (journal) , thermodynamics , materials science , composite material , physics , organic chemistry
Total and static holdups have been measured for 1/2‐, and 1‐in. ceramic Berl saddles, 1/2‐, 1‐, and 1 1/2‐in. ceramic Raschig rings, and 1‐in. carbon Raschig rings with air rates from 100 to 1,000 1b./(hr.) (sq. ft.) and water rates from 1,000 to 10,000 1b./ (hr.) (sq. ft.). The holdup measurements and motion picture observations of the flow of dye solutions through packings provide an explanation for the great differences observed when gas‐phase mass transfer rates are measured by absorption and vaporization methods. If the effective interfacial area for vaporization is assumed to be proportional to total holdup and the area for absorption is assumed proportional to operating holdup, the raio of the two mass transfer rates should be equal to the ratio of the two holdups. The departure from equality of the two ratios can be explained by the observation that the static holdup is displaced slowly, resulting in additional effective area for absorption over that expected from the operating holdup alone.