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Mass transfer in the entrance region for axial and swirling annular flow
Author(s) -
de Sa M. S.,
Shemilt L. W.,
Soegiarto I. V.
Publication year - 1991
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450690136
Subject(s) - laminar flow , mass transfer , turbulence , mechanics , flow (mathematics) , mass flow , inlet , physics , core (optical fiber) , geology , optics , geomorphology
Rates of mass transfer to the inner core of an annular flow system have been determined for the mass transfer entry region using the limiting current density method. Both in laminar and turbulent flow, the hydrodynamic and concentration boundary layers were not fully developed. The variation of the mass transfer coefficients with length of core section has been demonstrated, and the data for swirling flow correlated by the equation\documentclass{article}\pagestyle{empty}\begin{document}$$ Sh = 0.408Re^{0.727} Sc^{0.284} \left({L/D_c} \right)^{-0.235} $$\end{document}for 1500< Re < 14000, 1500 < Sc < 6200 and 1.75 < L / D e < 10.14. The data for axial flow in the entry region have been correlated by the equation.\documentclass{article}\pagestyle{empty}\begin{document}$$ Sh = 0.240Re^{0.692} Sc^{0.33} $$\end{document}for 1800 < Re < 12500 and Sc = 2604. Mass transfer enhancement in the entry region due to swirl when compared to axial flow‐systems with a jetting transverse inlet is only noticeable for Re > 6000, but is very significant compared to systems with fully developed boundary layers in axial or swirling flow.