MASS TRANSFER BY FREE CONVECTION AT INCLINED ELECTRODES

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 CuSO4 in 1·5 M H2SO4; limiting currents for deposition of copper were between 0·23 and 37 mA/cm2. A general correlation of the data of all inclinations may be represented by the equation Nu = 0·3 (C Sc Gr)0·28, where Nu, Sc and Gr are the masstransfer Nusselt, Schmidt, and Grashof numbers, respectively and C is a constant depending on the angle of inclination. The experimental range used in the correlation was 6 × 1010 < Sc Gr < 7 × 1013. The correlation for the results of the individual obtuse angles indicates that the boundary layer is turbulent. © 1969.