Studies on Mass and Momentum Transfer at the Outer Wall of a Circular Conduit with Entry Region Spiral Tape Wound on Rod as Turbulence Promoter in Homogeneous Flow

Abstract

In this study, an experimental investigation is carried out for augmentation of mass transfer coefficients in homogeneous flow by inserting spiral tape wound on rod in a circular conduit. Mass transfer coefficients are evaluated from the limiting current densities and the concentrations of the reacting ions. The variables studied are the geometric parameters of the promoter width, height, pitch of the promoter and the flow rate of the electrolyte, each parameter effect on mass transfer and momentum transfer are investigated. Experiment is conducted for 48 promoters with varying geometric parameters. Reynolds number range covered in the experiment is 4853–14533. Improvement in mass transfer is assessed by comparing the obtained mass transfer coefficient (kL) values with the smooth tube data. It is found that kL increased with increased flow rate. The increase in tape height and width of the promoter resulted in slightly increased mass transfer coefficients. Pitch of the promoter showed marginal effect on kL. Keywords: Turbulence promoter, spiral tape wound, limiting current densities, turbulence promoter, homogeneous flow