Mass transfer in relation to flow induced corrosion of the bottom of cylindrical agitated vessels

A study of the effect of drag-reducing surfactants on flow patterns in stirred vessels

“…Koshy et al (1989) investigated the effect of the addition of a polymer -poly(acrylamide) (PAM, often referred to previously in literature as "PAA") -in a dispersion of organic solvents (toluene, octanol) in water in a stirred vessel equipped with a disk impeller with or without blades, finding that the presence of the drag reduction agent (DRA) resulted in the production of a dispersion with larger drops. Sedahmed et al El-Shazly et al, 2004) used a suspension of poly(ethylene oxide) particles in a stirred vessel and found that drag-reducing solid polymers reduced the rate of diffusion-controlled corrosion; these results were consistent with their previous results about the reduction of mass transfer by DRAs. Mishra et al (1998) investigated the effect of PAM on flow patterns in a vessel stirred with a Rushton turbine, for three different DRA concentrations; they presented the results in the form of velocity profile plots, showing the magnitude of the mean and r.m.s.…”

Mass-Transfer-Controlled Impingement Corrosion at the Jet Inlet Zone of an Annulus under Turbulent Flow

“…Although the problem of inlet-zone impingement corrosion is well-described qualitatively in the literature, , little has been done to quantify it. Previous studies ascribe impingement corrosion to suspended solids or turbulence which destroy the protective solid film which may exist on the metal and enhance the rate of corrodent diffusion to the bare metal surface. − The aim of the present work is to correlate the rate of diffusion-controlled impingement corrosion of the inner cylinder of an annulus with the controlling variables such as solution velocity, physical properties of the solution, and inlet nozzle diameter. Advance knowledge of the rate of impingement corrosion would make it possible to assess the corrosion allowance needed in the design stage of annular equipment; it would also assist in predicting the lifetime of already-existing equipment.…”

The use of neural network to estimate mass transfer coefficient from the bottom of agitated vessel

“…4). The dimensional analysis for the mass transfer correlation for this system can be found in [57].…”

“…The positive exponent of the Re number indicates that the mass transfer increases with the increase of the degree of turbulence in the tank. Also the mass transfer decrease with the increase of the angle of inclination of the bottom which is attributed to the decrease in the degree of turbulence which reaches the bottom[57].…”