Process intensification is a never ending desire for process engineers. It has been carried out for either for efficient operation or to bring down production cost to a minimum. To that effect, process engineers are developing their process all the time. Electrochemical reactor design is not an exception to this norm. To achieve this task number of approaches has been resorted. Use of turbulence promoter is apart of such an effort. The turbulence promoters are of several kinds. Applications of additives to the reaction system, adaptation of mixing devices in the reactor are the principal techniques. Among them use of baffles, stirrers, liquid jets, spargers, use of various geometries immersed in the flow, and the use of two phase, three phase and multiphase flows are commonly adopted. The list is long and the visualization of a technique is the creativity of a process engineer. Among them, use of geometric objects in the flow streams has been receiving the attention of the several workers. Use of orifices in tubular flow systems is not new but studies on axially placed orifices in a series in meager. An orifice generators form friction both in upstream and downstream sides, thus generated friction continuous to shower their effect on wall mass transfer coefficients to longer lengths along the cell. The flow field generated by this type of promoters could not be explained properly by the earlier workers. The enhancements of mass transfer coefficient are not satisfactory at a distance from the orifice under consideration. Because of this reason use of multiple orifices in series transverse to the flow has been used by several workers in their studies. The studies mentioned above enhanced mass transfer to a reasonable extent, on the other hand the transfer coefficients obtained are not uniform along the length of the reactor. Moreover, they showed oscillatory behavior with distance. The generated oscillations are of decaying nature along the path of the flow. Present work is oriented to study the local variation in mass transfer coefficient and to measure the mass transfer coefficients along inner surface of the cell wall. When a series of orifices are placed transverse to the flow, the generated flow fields are complex and of highly rotational. It will enhance transfer coefficient exponentially. In order to harness these benefits, a series of orifice are placed in the tubular cell of circular cross section with varying distances between the consecutive discs. The selected geometry has exhibited good mass transfer efficiency. In the present study orifice diameter Do and orifice to orifice distance ‘h' were varied and the experiments are conducted. They yielded 3 to 12 fold enhancements over the reactor without orifices. Mass transfer coefficient increased with decrease in orifice diameter and orifice-orifice distance. An attempt has been made to identify the best combination of Do and h. they yielded 5mm, 30cm, combination is promising. However, overall energy efficiency of the cell can be obtained only with the variation of dynamic variable and velocity together with cost of promoter under consideration. Correlations were also presented for the relative augmentation factor to velocities for each promoter. Generalized correlations were developed in the present study and are presented here. Overall region: Log (g+) = 11.067 (Re)-0.25 (Do/D)-0.5 (h/Do)-0.08 Upstream region: Log (g+) = 21.469 (Re)-0.32 (Do/D)-0.41 (h/Do)-0.02 Downstream region: Log (g+) = 3.682 (Re)-0.21(Do/D)-0.58(h/Do)-0.32 Thus presented correlations and information generated are highly useful for the design and development of energy efficient electrochemical cells.

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