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Mass transfer coefficient of tubular ultrafiltration membranes under high‐flux conditions
Author(s) -
Akamatsu Kazuki,
Ishizaki Keita,
Yoshinaga Shotaro,
Nakao Shinichi
Publication year - 2018
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.16052
Subject(s) - ultrafiltration (renal) , membrane , mass transfer , suction , flux (metallurgy) , mass transfer coefficient , chemistry , thermodynamics , diffusion , mass flux , turbulence , flow (mathematics) , mechanics , chromatography , analytical chemistry (journal) , physics , biochemistry , organic chemistry
The effect of suction flow on the mass transfer coefficient of tubular ultrafiltration membranes, in particular that under a high‐flux condition, was studied. We pointed out thatN S his proportional toN R e0.875N S c0.25under turbulent conditions, and that the proportional constant, b, exceeds 0.023 when the effect of suction flow is not negligible. We conducted the velocity variation method using ultrafiltration membranes with MWCOs of 20k and 100k and dextrans having molecular weights of 40,000 and 70,000 at the conditions, whereN R eexceeded 3.6 × 10 3 . We demonstrated that the effect of suction flow includes not only flux but also the diffusion coefficient of solute, and that the ratio of the flux to the diffusion coefficient, expressed asNP e w, is an important index. Finally, we concluded that b = 0.023 , whenNP e wis smaller than 2.23 × 10 3 , giving the Deissler equation itself, and that b = 2.04 × 10 − 6 ×NP e w1.21, whenNP e wexceeds 2.23 × 10 3 . © 2017 American Institute of Chemical Engineers AIChE J , 64: 1778–1782, 2018