Mass Transfer Coefficient Enhancement Using Spiral Wound Rod as Turbulence P romoter in an Electrolytic Cell

Abstract

Objectives: to improve efficiency of process equipment by increasing the mass transfer coefficient with a spirally wound rod as the turbulence promoter. Methods:The function of facet promoters, whirl generators, and test sections of different congruous shapes increase the mass transfer coefficients at the reaction surface. Diffusion-controlled redox (ferricyanide - ferrocyanide) reaction has been chosen for the study. Limiting current data from the reduction of ferricyanide is used for mass transfer coefficient calculation. A set of three geometric parameters such as pitch(P), height(H), and width(W) of the promoter were investigated in the current study. Findings: An increase in the mass transfer coefficient values with the increment of flow rate of electrolyte from 0.088 m/s to 0.263 m/s was observed. A rise in the promoter height from 0.03 to 0.07m enhanced the mass transfer coefficient by 25.7 fold, while the increase in the width of the promoter from 0.01 to 0.04m resulted in a rise of the mass transfer coefficient by 26.3 fold. On the contrary, the mass transfer coefficient decreased upon increase in the pitch of the promoter from 0.01 to 0.04m, but overall enhancement is 25.7 fold. The increase in the mass transfer coefficient on an average compared to a rectangular turbulence promoter was 5.71 fold. Novelty: The spiral wound rod as a promoter increased the mass transfer coefficient several folds compared to other promoters. The spiral wound rod is quite simple to manufacture, has low cost and ease of maintenance. Therefore, the promoter used in the study could be employed for heat and/or mass transfer enhancement in Industrial applications. Keywords: Limiting current; Promoter; Mass transfer Coefficient; Swirl flow; Redox reaction