Mass transfer studies on an electrode support in an electrolytic cell:
New techniques are being developed to augment the transfer rates and hence the efficiency of the electrolytic cell. In industrial operations, increased transfer rates result in equipment size reduction, increased productivity, and higher purity of the product. Many of electrochemical processes suffer in varying degrees from mass transfer limitations which require operations in less economic conditions. In electrolytic cells, excessive increase in current density causes the cathode unacceptably rough, porous, and impure. Usually the operating current density in the tank cell is 60% less than the limiting current density. Judicious selection of the current density is an important factor in the economic operation of the cell and for good quality of the deposit. The limiting current density is the maximum rate of ion discharge under the experimental conditions. This is an important factor in the economic operation of the cell.
The process of improving the performance of a system by any technique is known as mass transfer augmentation or intensification. Basic feature of any augmentation technique is to enhance the transfer rates by increasing turbulence in the flow though it makes the system more complicated. The presence of an augmentation technique in an electrolytic cell can increase the intensity of local turbulence that enhances the mass transfer coefficient at the transfer surface. Insertion of baffles on cell wall also increases the mass transfer coefficient and corresponding pumping energy. Theoretical Study of Interphase Mass Transfer, A