FREE CONVECTIVE MASS-TRANSFER AT VERTICAL CYLINDRICAL ELECTRODES OF VARYING ASPECT RATIO

A limiting current technique was used for the measurement of the free convection mass transfer rate at entire vertical cylinders with varying aspect ratio. The mass transfer rates at the single surfaces were in good agreement with the mass transfer data in the literature. Mass transfer rates at a combination of a downward-facing horizontal and a vertical surface was controlled by the downward-facing horizontal surface (for cylinder aspect ratios lower than 2). It was found that the entire surface measured mass transfer rate was lower than that predicted by summation of the mass transfer rate at the individual surfaces. An interference factor, f, was introduced for correlation of the total mass transfer data for the full range of cylinders together. The dependence of the interference factor on the aspect ratio of the cylinder (L/r) was established.