Turbulent natural convection in electrolysis with vertical electrodes was studied by a dark field method (making the flow pattern visible) and by the method of the current/voltage curve(yielding the limiting current and the mass transfer rate). The range studied (2 x 101'< SC Gr < 1016) included the
Natural convection mass transfer at vertical electrodes
โ Scribed by M.G. Fouad; T. Gouda
- Publisher
- Elsevier Science
- Year
- 1964
- Tongue
- English
- Weight
- 424 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0013-4686
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โฆ Synopsis
The ferricyanideferrocyanide redox system was studied undernaturalconvection conditions at vertical nickel electrodes by observations of the limiting current density of the cathodic process for electrodes of different heights. In the range 9 x 100 < ScGr < 4.57 x 101' the results lead to Nu = 0.45(ScGr)"*"5, where SC is the Schmidt number, Gr the Grasshof number and Nu the Nusselt number. In the range 457 x 10" < ScGr < 10" the results lead to Nu = 0.15(ScGr)".80.
R&um&Le systime r&lox ferri-ferrocyanure est 6tudit scion les conditions de convexion naturelle sur &&odes de Ni verticales, au moyen de la densite de courant limite du processus cathodique g diff&entes hauteurs. SC designant le nombre de Schmidt, Gr celui de Grasshof, Nu celui de Nusselt on a obtenu: Nu = 0,45 (ScGr)"@ pour 9 . log < ScGr < 4,57 . 10" et Nu = 0,15 (ScGr)O+a pour 4,57 . 1O1' < ScGr < 1014. Zusammenfassung-Es wurden die Grenzstriime der Reduktion von Ferricyanid zu an senkrechten Nickelkathoden verschiedener Hiihe unter Bedingungen der nattilichen Konvelction gemessen. Im Bereich 9 x loo < ScGr < 4,57 x 10" kannen die Ergebnisse durch die Korrelation Nu = 0,45(ScGr)"@ ausgedriickt werden, wobei SC die Schmidtsche Zahl, Gr die Grashof'sche Zahl und Nu die Nusseltsche Zahl bedeuten. Im Bereich 4,57 x 10" < ScGr < 10'4 kannen die Ergebnisse durch die Eteziehung Nu = 0,15(ScG~)~~*~ dargestellt werden.
๐ SIMILAR VOLUMES
The free convection mass-transfer behaviour of upward-facing horizontal surfaces has been investigated experimentally using an electrochemical technique involving the measurement of limiting currents for the deposition of copper on copper electrodes from acidiied cupric sulphate solutions. The data
Abatraet-Cathodic limiting currents were measured in an unstirred cell at inclined parallel electrodes, with angles of inclination between 30" and 150". Cathode heights varied from 10 cm to 50 cm, and electrolyte composition from 0.01 to 0.25 M CuSO, in 15 M H&IO,; limiting currents for deposition o