NATURAL-CONVECTION MASS-TRANSFER AT A HORIZONTAL CYLINDER ELECTRODE WITH AN OPPOSED THERMAL BUOYANCY EFFECT


SARAÇ H. , Wragg A., Patrick M.

ELECTROCHIMICA ACTA, cilt.38, ss.2589-2598, 1993 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 38 Konu: 17
  • Basım Tarihi: 1993
  • Doi Numarası: 10.1016/0013-4686(93)80157-u
  • Dergi Adı: ELECTROCHIMICA ACTA
  • Sayfa Sayısı: ss.2589-2598

Özet

Simultaneous heat and mass transfer at horizontal cylinder electrodes in free convection has been investigated experimentally using the electrochemical limiting diffusion current technique, in the situation where the concentration and thermal buoyancy effects are opposed. The ferri-ferrocyanide redox system was used for the mass transfer measurements, the electrolyte system being equimolar potassium ferri-ferrocyanide with 0.5 M NaOH as supporting electrolyte. The chosen concentrations were 0.01, 0.02, 0.05, 0.10 and 0.2M. Two different nickel cylinders of diameter of 33.2 and 21.3mm were used, each 100mm in length. The surface temperature of the cylinder varied from 20%C (isothermal) to 85%C. Results for the opposed upward and downward convection were correlated using a combined Grashof number for mass transfer in the range 10(8)