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    Solid-Liquid Mass Transfer in the Annular Region of a Taylor-Couette Contacting Device

    , M.Sc. Thesis Sharif University of Technology Faraji Dizaji, Naeimeh (Author) ; Molaei Dehkordi, Asghar (Supervisor)
    Abstract
    Vortex flow reactor (VFR) is used for biochemical reactions and separation applications. By using the second flow regime, called Taylor-Couette flow, VFR provides high amounts of mass transfer and mixing for biological components sensitive to shear stress. Mass transfer in a bench-scale Taylor-Couette contactor with a radius ratio, equal to 0.77 and an aspect ratio, equal to 30.7 was studied for solid particles dissolution. The working fluid was water and the suspended particles were benzoic acid. In this project the concentration of fluid phase was measured by injection of definite amount of the solid particles in to the contactor and sampling in different time intervals and the effects of... 

    Tube bundle heat and mass transfer characteristics in falling film absorption generators

    , Article International Communications in Heat and Mass Transfer ; Volume 30, Issue 4 , 2003 , Pages 565-576 ; 07351933 (ISSN) Jani, S ; Saidi, M. H ; Mozaffari, A. A ; Sharif University of Technology
    2003
    Abstract
    Falling film heat and mass transfer analysis of a horizontal tube bundle in a generator of absorption chillers have been studied. The film Reynolds number is limited to the laminar flow and the effect of ripple on the free surface has been ignored. Thermal boundary conditions are considered to be constant wall temperature and desorption is considered to be free surface evaporation. Analysis is based on a single column of horizontal tubes, arranged in a vertically spaced configuration. A comprehensive numerical code has been developed to solved the governing equations. The functional relationship of average heat transfer coefficient of tube bundle has been analytically correlated to the first... 

    A new approach to heat and mass transfer in a rotary dehumidifier: Modeling and simulation

    , Article 2005 ASME Fluids Engineering Division Summer Meeting, FEDSM2005, Houston, TX, 19 June 2005 through 23 June 2005 ; Volume 2005 , 2005 , Pages 1268-1273 ; 0791837602 (ISBN); 9780791837603 (ISBN) Esfandiarinia, F ; Van Paassen, D ; Saidi, M. H ; ASME Fluids Engineering Division ; Sharif University of Technology
    2005
    Abstract
    In this paper the analytical and simulation modelling of the combined heat and mass transfer processes that occur in a solid desiccant wheel is carried out. Using the numerical method, the performance of an adiabatic rotary dehumidifier is parametrically studied, and the optimal rotational speed is determined by examining the outlet adsorption-side humidity profiles. An approach to compare the solutions for different conditions used in air dehumidifier has been investigated according to the previous published studies. Comparing the simulated results with the published actual values of an experimental work substantiates the validity of model. The model accuracy with respect to the key... 

    A new method to calculate efficiency of randomly-packed distillation columns and its comparison with the methods utilized in ASPEN Plus

    , Article Fuel Processing Technology ; Volume 96 , 2012 , Pages 65-73 ; 03783820 (ISSN) Sadeghifar, H ; Sadeghifar, A ; Sharif University of Technology
    2012
    Abstract
    In this paper, a unique and applicable method was developed for calculation of efficiency (and mass and heat transfer coefficients) of randomly-packed distillation columns. This method has potential advantages; e.g., unlike all the available methods, it can calculate efficiency without using any empirical mass transfer and hydraulic correlations, and without the need to estimate the operational and hydraulic parameters of an operating column. It, therefore, will be free of errors and limitations of such empirical items and can be used for efficiency calculation of any random packing including new ones. Along with an analysis of the proposed method, the paper also presents a thorough analysis... 

    Investigation of Mass Transfer in Liquid-Liquid System in the Presence of Nanosized Particles

    , M.Sc. Thesis Sharif University of Technology Nakhaeipour, Fahimeh (Author) ; Bastani, Dariush (Supervisor)
    Abstract
    The main objective of this project is to study the effect of the presence of nanoparticles on mass transfer in liquid-liquid systems. To do this research, TiO2/water, Al2O3/water, CNTs/water and CNTs/toluene have been used as nanofluids. The experiments of TiO2/water nanofluid were been carried out in water-acetone-toluene system at two weigh percents of TiO2 nanoparticles. The result showed that mass transfer decreased in 0.5wt% of TiO2, compared to base fluid, and it increase in 1 %wt. Also in 0.5%wt the decrease in interfacial tension decreased diameter of drops and as a result mass transfer decreased too. In 1%wt the increase in viscosity increased the diameter of drops and then the... 

    Evaluation of interfacial mass transfer coefficient as a function of temperature and pressure in carbon dioxide/normal alkane systems

    , Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 51, Issue 4 , April , 2015 , Pages 477-485 ; 09477411 (ISSN) Nikkhou, F ; Keshavarz, P ; Ayatollahi, S ; Raoofi Jahromi, I ; Zolghadr, A ; Sharif University of Technology
    Springer Verlag  2015
    Abstract
    CO2 gas injection is known as one of the most popular enhanced oil recovery techniques for light and medium oil reservoirs, therefore providing an acceptable mass transfer mechanism for CO2–oil systems seems necessary. In this study, interfacial mass transfer coefficient has been evaluated for CO2–normal heptane and CO2–normal hexadecane systems using equilibrium and dynamic interfacial tension data, which have been measured using the pendant drop method. Interface mass transfer coefficient has been calculated as a function of temperature and pressure in the range of 313–393 K and 1.7–8.6 MPa, respectively. The results showed that the interfacial resistance is a parameter that can control... 

    The effect of nanoparticles on the mass transfer in Liquid–Liquid extraction

    , Article Chemical Engineering Communications ; Volume 202, Issue 5 , Sep , 2015 , Pages 600-605 ; 00986445 (ISSN) Mirzazadeh Ghanadi, A ; Heydari Nasab, A ; Bastani, D ; Seife Kordi, A. A ; Sharif University of Technology
    Taylor and Francis Ltd  2015
    Abstract
    This article investigates the effect of nanoparticles on mass transfer in the liquid–liquid extraction for the chemical system of n-butanol–succinic acid–water. For this purpose, nanofluids containing various concentrations of ZnO, carbon nanotubes (CNT), and TiO2 nanoparticles in water, as base fluid, were prepared. To examine the flow mode effect on mass transfer rate, different fluid modes including dropping and jetting were employed in the process. Results show that mass transfer rate enhancement depends on the kinds and the concentration of nanoparticles and the modes of flow. It was observed that after adding nanoparticles, the mass transfer rate significantly increases up to two-fold... 

    Performance optimization of polymeric porous membrane-based liquid desiccant air dehumidifier used in air conditioning system

    , Article International Journal of Energy and Environmental Engineering ; Volume 11, Issue 1 , December , 2020 , Pages 55-71 Jafarpour, A. M ; Fazelpour, F ; Mousavi, S. A ; Sharif University of Technology
    Springer  2020
    Abstract
    In this study an experimental design was developed to optimize the performance and structure of a membrane-based parallel-plate liquid desiccant dehumidifier used in air conditioning regeneration system which operates under high humidity weather conditions. We conducted a series of polymeric porous membranes with different compositions fabricated that were prepared with various weight percentages of polysulfone (PSU), mixed with N-methyl-2-pyrrolidone (NMP) and dimethyl form amide (DMF) solvents. Furthermore, the designed experiments were performed under various operating conditions, indicating that the dehumidification efficiency declines with increasing flow rate, temperature, and... 

    Experimental investigation in pool boiling heat transfer of pure/binary mixtures and heat transfer correlations

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 27, Issue 3 , September and October , 2008 , Pages 135-150 ; 10219986 (ISSN) Alavi Fazel, S. A ; Jamialahmadi, M ; Safekordi, A. A ; Sharif University of Technology
    2008
    Abstract
    Nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid binary mixtures. Measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. In this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in pure component liquids with same physical properties. Several reasons should be responsible for this phenomenon, but mainly it could be related to preferential evaporation of the more volatile component(s) during bubble formation. In this article, the performances of major existing correlations to the... 

    Computational analysis of heat and mass transfer in a micropolar fluid flow through a porous medium between permeable channel walls

    , Article International Journal of Nonlinear Sciences and Numerical Simulation ; 2021 ; 15651339 (ISSN) Ahmad, S ; Ashraf, M ; Ali, K ; Nisar, K. S ; Sharif University of Technology
    De Gruyter Open Ltd  2021
    Abstract
    The present work numerically investigates the mass and heat transport flow of micropolar fluid in a channel having permeable walls. The appropriate boundary layer approximations are used to convert the system of flow model equations in ODEs, which are then numerically treated with the quasi-linearization method along with finite difference discretization. This technique creates an efficient way to solve the complex dynamical system of equations. A numerical data comparison is presented which assures the accuracy of our code. The outcomes of various problem parameters are portrayed via the graphs and tables. The concentration and temperature accelerate with the impacts of the Peclet numbers... 

    Computational analysis of heat and mass transfer in a micropolar fluid flow through a porous medium between permeable channel walls

    , Article International Journal of Nonlinear Sciences and Numerical Simulation ; 2021 ; 15651339 (ISSN) Ahmad, S ; Ashraf, M ; Ali, K ; Nisar, K. S ; Sharif University of Technology
    De Gruyter Open Ltd  2021
    Abstract
    The present work numerically investigates the mass and heat transport flow of micropolar fluid in a channel having permeable walls. The appropriate boundary layer approximations are used to convert the system of flow model equations in ODEs, which are then numerically treated with the quasi-linearization method along with finite difference discretization. This technique creates an efficient way to solve the complex dynamical system of equations. A numerical data comparison is presented which assures the accuracy of our code. The outcomes of various problem parameters are portrayed via the graphs and tables. The concentration and temperature accelerate with the impacts of the Peclet numbers... 

    Estimation of mass transfer during drop formation: New flow expansion model

    , Article 2004 ASME International Mechanical Engineering Congress and Exposition, IMECE, Anaheim, CA, 13 November 2004 through 19 November 2004 ; 2004 , Pages 27-34 ; 0791847179 (ISBN); 9780791847176 (ISBN) Javadi, A ; Bastani, D ; Sharif University of Technology
    American Society of Mechanical Engineers  2004
    Abstract
    Although there is extensive experimental, theoretical and numerical research on dynamics of drop formation in liquid-liquid systems, the evaluation of mass transfer during drop formation is rather complex and there has been little research on that. The various mathematical models developed for this problem are generally based on a solution of the diffusion equation without any allowance for circulation within the drop. This is the main reason for the poor prediction of these models in many cases for which internal convection has an important effect on mass transfer rate. In this paper an attempt was made to define a parameter related to the extent of the convective mixing within the growing... 

    Vapor absorption into liquid films flowing over a column of cooled horizontal tubes

    , Article Scientia Iranica ; Volume 11, Issue 4 , 2004 , Pages 332-338 ; 10263098 (ISSN) Farhanieh, B ; Babadi, F ; Sharif University of Technology
    Sharif University of Technology  2004
    Abstract
    In this paper, a theoretical analysis of the combined heat and mass transfer over cooled horizontal tubes is presented. The boundary layer assumptions are used for the transport of mass, momentum and energy equations and the finite difference method is employed to solve the governing equations in the absorber tube bundle. The effects of important parameters, such as solution flow rate, absorber pressure and tube radius, are discussed on the overall heat and mass transfer for a tube and tube bundle. © Sharif University of Technology, October 2004  

    Investigation the effect of super hydrophobic titania nanoparticles on the mass transfer performance of single drop liquid-liquid extraction process

    , Article Separation and Purification Technology ; Volume 176 , 2017 , Pages 107-119 ; 13835866 (ISSN) Hatami, A ; Bastani, D ; Najafi, F ; Sharif University of Technology
    Abstract
    Hydrophobic titania nanoparticles were synthesized by a novel in situ sol-gel method and applied in a single drop liquid-liquid extraction column to enhance the overall dispersed-phase mass transfer coefficient (Kod). The chemical system of toluene, acetic acid and water was used, and the direction of solute (acetic acid) mass transfer was from dispersed phase, including: toluene and acetic acid to the continuous phase of water. For such system, much of the mass transfer resistance exists in the dispersed phase, which is nonpolar organic liquid. Hence, modified titania nanoparticles (MTNP's), prepared by sol-gel route, in five different concentrations of 0.001–0.005 wt.% were added in the... 

    The investigation of natural super-cavitation flow behind three-dimensional cavitators: Full cavitation model

    , Article Applied Mathematical Modelling ; Volume 45 , 2016 , Pages 165-178 ; 0307904X (ISSN) Kadivar, E ; Kadivar, Erfan ; Javadi, K ; Javadpour, S. M ; Sharif University of Technology
    Elsevier Inc 
    Abstract
    In this study, natural super-cavitating flow around three different conical cavitators with wedge angles of 30°, 45° and 60° is investigated. We apply the k−ϵ turbulence model and the volume of fluid (VOF) technique to numerically study the three-dimensional cavitating flow around the cavitators. The turbulence approach is coupled with a mass transfer model which is implemented into the finite-volume package. Simulations are performed for different cavitation numbers. Finally, the effects of some important parameters such as the cavitation index, inlet velocity, Froude number and wedge angle of cavitators on the geometrical characteristics of the super-cavities are discussed. Our numerical... 

    Model for excess mass-transfer resistance of contaminated liquid-liquid systems

    , Article Industrial and Engineering Chemistry Research ; Volume 46, Issue 5 , 2007 , Pages 1563-1571 ; 08885885 (ISSN) Molaei Dehkordi, A ; Ghasemian, S ; Bastani, D ; Ahmadpour, N ; Sharif University of Technology
    2007
    Abstract
    The prediction of mass-transfer rates into and from moving drops in the liquid-liquid systems has usually used the well-known Whitman two-film theory approach. According to the latter, the total resistance to mass transfer resides on each side of the interface and is described by the individual film mass-transfer coefficients for the continuous and dispersed phases in the absence of surface-active agents (contaminants). In the present work, the same approach has been used to model the excess mass-transfer resistance exerted by surface-active agents in the continuous phase. To achieve this goal, an experimental investigation has been conducted on the mass transfer into and from single drops... 

    Proficiency of tellurium extraction in pulsed disc and doughnut columns

    , Article Separation Science and Technology (Philadelphia) ; Volume 56, Issue 18 , 2021 , Pages 3092-3105 ; 01496395 (ISSN) Shakib, B ; Torkaman, R ; Torab Mostaedi, M ; Asadollahzadeh, M ; Sharif University of Technology
    Taylor and Francis Ltd  2021
    Abstract
    In this research, the separation of tellurium from selenium was studied from chloride solution by TBP extractant. In the batch experiments, the experimental findings indicated that the feed acidity, TBP concentration, and contact time were optimized to achieve the high separation factor. In continuous mode of pulsed disc and doughnut column, the impacts of operating parameters have been discussed on the distribution coefficients of selenium and tellurium, and mass transfer enhancement. A new model for predicting Koca was proposed in terms of holdup values, Sherwood, Reynolds, and Schmidt numbers, which has an acceptable agreement with the mass transfer data. © 2020 Taylor & Francis Group,... 

    Lipoxygenase-1 mass-transfer coefficient in aqueous two-phase system using spray extraction column

    , Article Industrial and Engineering Chemistry Research ; Volume 44, Issue 19 , 2005 , Pages 7469-7473 ; 08885885 (ISSN) Arsalani, V ; Rostami, K ; Kheirolomoom, A ; Sharif University of Technology
    2005
    Abstract
    Extraction of lipoxygenase-1 was investigated by using the aqueous two-phase system formed by sodium sulfate-poly(ethylene glycol)-buffer. The extraction was performed in a 47-mm inner diameter spray column, operating in a semibatch manner. The effects of dispersed-phase flow rate and phase compositions on fractional dispersed-phase hold up (εD) and volumetric masstransfer coefficient (KDa) were respectively studied. It was found that the hold-up and volumetric mass-transfer coefficient increased with an increase in dispersed-phase velocity and decreased with increasing phase composition. Correlations have been developed by nonlinear regression for estimation of fractional dispersed-phase... 

    Prediction of the Contribution of Mass Transfer During Jet Formation in Liquid-Liquid Extraction Columns

    , M.Sc. Thesis Sharif University of Technology Taleshi, Navid (Author) ; Sayf Kordi, Ali Akbar (Supervisor)
    Abstract
    There are many different opinions about the mass transfer contribution during jet formation in liquid - liquid extraction columns, and this could impact on their design. In this work, using experimental data obtained in two RDC columns and unpublished data of the jet mass transfer coefficients, mass transfer can be predicted during jet formation. The jet length and diameter were anticipated by using existing relations, and then the jet mass transfer coefficient was predicted, jet mass transfer rate and total column mass transfer rate were calculated and finally the contribution of mass transfer during jet formation in the column was predicted. Mass transfer contribution in the jet in various... 

    , M.Sc. Thesis Sharif University of Technology Sarrafan, Kiana (Author) ; Bastani, Daruoosh (Supervisor)
    Abstract
    In liquid-liquid extraction, as in gas absorption, two phases must be brought into good contact to permit transfer of material. The presence of nanoparticles in liquid phase can enhanced the rate of gas-liquid mass transfer. The benefits of nanofluids can be used to enhance the heat and mass transfer of liquid-liquid extraction. Standard test system with low interfacial tension that recommended by EFCE: n-butanol/water/succinic acid, was used in this project. The CNTs/n-butanol that was saturated of water used as dispersed phase. Water and succinic acid used as continuous phase and solute. Since there is no chemical reaction to take place between CNTs and n-butanol, In order to obtain well...