InterfaceMTCoeff

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Chapter 13 Interface mass transfer (Material presented in this chapter are based on those in Chapters 8 and 13, �Diffusion mass transfer in fluid systems� second edition by EL Cussler) In chapter (7), methods to estimate mass transport coefficients for transport from a homogeneous solutions into wall were derived. There are several situations in which the transport of a solute species occurs from one fluid phase into another fluid phase, separated by a region called the interface. In the case where the bulk concentration in the two phases are constant, at the contact location there can be two possibilities. The first possibility is that there might be a jump discontinuity at the contact point of the two phases. This is possible only if the diffusivity in both the phases are infinity. As the diffusivity of the solute is finite in the phase, a jump discontinuity is unlikely to exist. This leads to the second possibility where there is a concentration gradient he near the contact point in the phase into which the solute is transported. This region where a concentration gradient exists is termed as the interface. In this chapter, different theories that characterize the concentration profile in the interface will be considered. Methods to estimate the overall mass transfer coefficients will be presented.

13.1

Mass transport driving force

13.1.1

Mass transport between two liquids

Consider the case of two well-mixed liquids that are immiscible. Suppose if the denser fluid, say 1 is placed in the container and lighter fluid, say 2 177


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InterfaceMTCoeff by Vikrant Raj - Issuu