Abstract (EN):
Mass transfer around a slightly soluble cylinder, aligned with the direction of liquid flow in a packed bed of sand particles, is analysed for transport by advection and molecular diffusion. The theoretical analysis applies to cylinders that are large in comparison with the inert panicles, so that the bed may be treated as a continuum. The elliptic equation resulting from a differential mass balance on an elementary bed volume was solved numerically over a wide range of the relevant parameters, and the resulting values of Sherwood number are seen to depend on the aspect ratio of the cylinder and on the Peclet number based on the cylinder length. Experimental measurements of mass transfer in water were carried out for a range of the relevant parameters. The soluble cylinders used in the experiments were made of either benzoic acid or 2-naphtol and the range of temperatures covered was 293-373 K. Using the mass transfer theory developed in this work the molecular diffusion coefficient of the two solutes was determined, and good agreement with literature values was found.
Language:
English
Type (Professor's evaluation):
Scientific