Convective Mass Transfer Coefficient Dr. Mustafa Nasser

Thus, for constant total concentration, The diffusion flux Mass Transfer Coefficients Defined as the rate of mass transfer per unit area per unit concentration difference based on equal molar flows. Depends on (in liquids or gases) diffusivity, face of the component, physical properties (density and viscosity) of the fluid, distance of diffusion and type of diffusion (equimolar diffusion or diffusion of A through B) Thus, for constant total concentration, The diffusion flux (1) Dr. Mustafa Nasser

Mass Transfer Coefficients Integrating & rearranging, Distance of the path, (z2 – z1) is often not know, thus (2) (3) Convective mass transfer coefficient Dr. Mustafa Nasser

Mass Transfer Coefficients Case: equimolar counter diffusion For the case of equimolar counter diffusion, where NA = -NB, integrating at steady state, where (4) (5) Dr. Mustafa Nasser

Dr. Mustafa Nasser

Mass Transfer Coefficients case of diffusion of A through stagnant B For liquid Dr. Mustafa Nasser

Mass Transfer Coefficients Dr. Mustafa Nasser

( with d = z2 – z1 ; ) Dr. Mustafa Nasser

Dr. Mustafa Nasser

Types of Mass Transfer Coefficients And driving force expressed Dr. Mustafa Nasser

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Typical Magnitudes of Mass Transfer Coefficient and Film Thickness Dr. Mustafa Nasser

Example Dr. Mustafa Nasser

Dr. Mustafa Nasser

Dr. Mustafa Nasser