Mechanical Engineering / Makina Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4129

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Department: search.filters.department.İzmir Institute of Technology. Chemical EngineeringSubject: search.filters.subject.Mass transfer

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  • Article
    Citation - WoS: 11
    Citation - Scopus: 11
    Comparison of Uniform and Non-Uniform Pressure Approaches Used To Analyze an Adsorption Process in a Closed Type Adsorbent Bed
    (Springer Verlag, 2013) Gediz İliş, Gamze; Mobedi, Moghtada; Mobedi, Moghtada; Ülkü, Semra; Ülkü, Semra; 03.10. Department of Mechanical Engineering; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Heat and mass transfer in an annular adsorbent bed filled with silica gel particles is numerically analyzed by uniform and non-uniform pressure approaches. The study is performed for silica gel-water pair, particle radius from 0.025 to 1 mm and two bed radii of 10 and 40 mm. For uniform pressure approach, the energy equation for the bed and the mass transfer equation for the particle are solved. For non-uniform pressure approach, the continuity and Darcy equations due to the motion of water vapor in the bed are added, and four coupled partial differential equations are solved. The changes of the adsorbate concentration, pressure, and temperature in the bed throughout the adsorption process for both approaches are obtained and compared. The obtained results showed that the particle size plays an important role on the validity of uniform pressure approach. Due to the interparticle mass transfer resistance, there is a considerable difference between the results of the uniform pressure and non-uniform pressure approaches for the beds with small size of particles such as 0.025 mm.
  • Article
    Citation - Scopus: 5
    Effect of Isotherm Shape on Mass Transfer in an Adsorbent Particle; an Isothermal Adsorption Process
    (Bentham Science Publishers B.V., 2011) Yıldırım, Zeynep Elvan; Gediz İliş, Gamze; Ülkü, Semra; Ülkü, Semra; Mobedi, Moghtada; 03.10. Department of Mechanical Engineering; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    The mass diffusion equation and corresponding initial and boundary conditions were non-dimensionalized for a spherical adsorbent particle in an infinite adsorptive medium to reduce number of independent governing parameters into two as mass transfer Biot number and dimensionless isotherm. The changes in local and average adsorbate concentration throughout the adsorption process were calculated and plotted for different values of mass transfer Biot numbers (ranging from 0.5 to 750) and for five different isotherm shapes. The obtained results indicated that the isotherm shape influences dimensionless period of adsorption, if the external mass transfer resistance is significant in the process. For those cases, the total dimensionless adsorption period for a convex shape isotherm is shorter than a concave one.