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Investigations of drop‐size‐distribution and mass transfer in gas‐stirred liquid‐liquid systems
Author(s) -
Frohberg Martin G.,
Gerlach Friedemann,
Handschuh Georg
Publication year - 1990
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199000322
Subject(s) - mass transfer , mechanics , drop (telecommunication) , chemistry , turbulence , surface tension , weber number , dispersion (optics) , analytical chemistry (journal) , thermodynamics , pressure drop , volumetric flow rate , reynolds number , chromatography , optics , telecommunications , physics , computer science
In cold model experiments of a bottom blown converter containing water and oil in different ratios the size distribution of the dispersed oil drops were measured directly by a special suction probe method. The computerized evaluation yields the relative frequencies of the drops in diameter classes versus the drop diameter. It was observed that increasing gas flow rates produce decreasing drop diameters. The type of the statistical function which describes the drop‐size distribution leads to the conclusion that the bottom blown dispersion mechanism is comparable to a hydropneumatic mill. The total distribution was calculated from three‐dimensional measurements. Under the experimental blowing conditions the overall transfer area exceeds that of the non‐stirred system by the factor 15. Additional measurements show the effect of changed conditions of the oil fraction and the interfacial tension. The second part of the investigation deals with measurements of the mass transfer of caprylic acid under dispersion conditions. The product of the transfer coefficient and the transfer area as an expression of the velocity of mass transfer increases with increasing gas flow rates in three ranges of different slope. An interpretation is given for this observation. Our own values of mass transfer velocity are comparable with industrial results of final decarburization in the bottom‐blown converter. Together with separate experiments with non‐disturbed interfaces it was found that the mass transfer is accelerated by a factor 10 to 100, according to the blowing conditions.