Consider a fluid layer A surrounded on both sides by a fluid, B. The fluid layer can be thought of as a membrane. A species S is diffusing across this membrane, and has concentrations c and c (in the fluid B) on the two sides of the membrane, as shown in Fig. 7.28. It often happens that the solubility of material S inside the membrane is different than its solubility in bulk solution B. We therefore define a partition coefficient k as concentration of S in material A (at equilibrium) (7.30) concentration of S in material B Hence k < 1 means that S is less soluble in the membrane, and k> 1 means S is more soluble. Write down an expression for the flux across the membrane in terms of c, c, DA (diffusion coefficient of S in A) and Aya. Sketch the concentration profile. What is the effective diffusion coefficient value with partitioning, De? Fluid A Fluid B Fluid B Concentration Concentration дуА Figure 7.28

Consider a fluid layer A surrounded on both sides by a fluid, B. The fluid layer can be thought of as a membrane. A species S is diffusing across this membrane, and has concentrations c and c (in the fluid B) on the two sides of the membrane, as shown in Fig. 7.28. It often happens that the solubility of material S inside the membrane is different than its solubility in bulk solution B. We therefore define a partition coefficient k as concentration of S in material A (at equilibrium) (7.30) concentration of S in material B Hence k < 1 means that S is less soluble in the membrane, and k> 1 means S is more soluble. Write down an expression for the flux across the membrane in terms of c, c, DA (diffusion coefficient of S in A) and Aya. Sketch the concentration profile. What is the effective diffusion coefficient value with partitioning, De? Fluid A Fluid B Fluid B Concentration Concentration дуА Figure 7.28

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.26P

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