FREE CONVECTIVE MASS-TRANSFER IT A CUBICAL OPEN CAVITY

Free convection mass transfer inside a cubical cavity was investigated experimentally by measuring the limiting currents for the cathodic de position of copper from acidified copper sulphate solutions. Cavity di mensions and CuSO4 concentration were varied to provide a range of Sc. Gr from 1.37 x 10(9) to 6 x 10(10) Under these conditions the data wer e found to fit the equation Sh = 0.259 (SC.Gr)(0.3) A comparison betwe en the measured overall rate of mass transfer inside the cavity with t hat calculated by adding the rates of mass transfer at the separate si des of the cavity showed that the measured value is higher than the ca lculated value owing to convective interaction between adjacent surfac es. To demonstrate the importance of the role played by cavity geometr y on the mass transfer behaviour of the cavity the present results wer e compared with the results obtained using different cavity geometries .