Enhancement of the Rates of Liquid‐Solid Heat and Mass Transfer in Annular Ducts by Using Circular Fins

Abstract

Rates of solid-liquid mass and heat transfer (by analogy) were measured at the outer surface of the inner tube of an annular duct under developing flow conditions using the electrochemical method that elaborates the measurement of the limiting current of the reduction of K 3 Fe(CN) 6 at the tested model surface. Variables examined were physical features of the solution (density r, viscosity m, and diffusivity D), solution superficial velocity, tube active length, and tube diameter. The experimental results were correlated by a dimensionless equation involving all affecting parameters. Due to the presence of the circular fins at the tube surface, the degree of mass transfer was enhanced by a factor ranging from two to six subject to the operative settings. Applications of the current findings in the design of catalytic reactors, membrane dialyzers, and double-pipe heat exchangers were discussed.