scholarly journals Mass Transfer Coefficient for Drying of Moist Particulate in a Bubbling Fluidized Bed

2009 ◽  
Vol 32 (1) ◽  
pp. 64-72
Author(s):  
Y. T. Makkawi ◽  
R. Ocone
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Bed ◽  
Bubbling Fluidized Bed

scholarly journals Electro Winning from Dilute Solutions at Enhanced Rates using Three-Phase Flow Reactor

2020 ◽  
Vol 9 (4) ◽  
pp. 1740-1745
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Bed ◽  
Flow Reactor ◽  
Liquid Velocity ◽  
Particle Diameter ◽  
Limiting Current ◽  
Process Equipment ◽  
Three Phase

Enhancement of mass transfer coefficient is highly desirable for economic design of process equipment. The present study is essentially carried out to know the effect of flow variables such as gas and liquid velocities and geometric parameters of the internal on mass transfer coefficients in a three phase fluidized bed. The mass transfer coefficient data were obtained using a string of cones internal in a three-phase fluidized bed electrochemical reactor. The flow system investigated was nitrogen, a fluid electrolyte and spherical glass beads as gas, liquid and solid phases respectively. Limiting current technique was employed to obtain mass transfer data. The internal comprises of a string of cones arranged concentrically on a central rod which is placed coaxially in a three phase fluidized bed. The presence of internal in three phase fluidized beds augmented the mass transfer coefficient significantly. In the present investigation it was found that the effect of gas velocity, liquid velocity, rod diameter and cone diameter was only marginal. However, the influence of pitch, half apex angle of cone and particle diameter was found to be significant. Correlations were developed based on least squares regression analysis for the prediction of mass transfer coefficient in terms of pertinent variables

scholarly journals A novel two-phase model for bubbling fluidized-bed CO-methanation reactor

2020 ◽  
Author(s):  
Quancong Zhang ◽  
Zhikai Cao ◽  
Songshou Ye ◽  
Yong Sha ◽  
Bing Hui Chen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Bed ◽  
Gas Flow ◽  
Flow Distribution ◽  
Co Methanation ◽  
Interphase Mass Transfer ◽  
Proposed Model

Fluidized bed reactor is promising for CO methanation owing to its excellent heat transfer performance. The gas flow distribution between the bubble and emulsion phases and mass transfer are important for such a solid-catalyzed fast reaction in fluidized bed but these are described simplistically in most conventional models. In this work, a novel model contemplating the gas flow distribution influenced by circulation flow and the interphase mass transfer coefficient influenced by bubble size variation is proposed. The simulation results of the proposed model and the classic Kunii–Levenspiel model were compared with experimental data of fluidized bed CO methanation. It was shown that the results of the proposed model have better agreement with experimental data. To evaluate the roles of gas flow distribution and interphase mass transfer coefficient, sensitivity analysis was carried out. The results indicated that in the proposed model, the effect of gas flow distribution is more important.

scholarly journals Mass Transfer Enhancement in GLS Fluidized Beds using Nanomaterials

2019 ◽  
Vol 8 (3) ◽  
pp. 5763-5766
Keyword(s):  
Mass Transfer ◽  
Benzoic Acid ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Bed ◽  
Fluidized Beds ◽  
Physical Property ◽  
Gas Velocity ◽  
Three Phase ◽  
Unique Physical Property

Nanomaterial has unique physical property which made it important for many applications and that is why the use of nanomaterials rapidly increasing in the field of science and engineering.1 . This work focuses on mass transfer of solids into liquid in three phase fluidized beds in presence of nanomaterial. This include the study of effect of gas velocity, time and different concentration of nanomaterials on mass transfer coefficient in stagnant liquid column in three phase fluidized bed system. To measure coefficient of the mass transfer, known quantity of solid pellets ie benzoic acid and known amount of nanomaterial fraction ie Arachitol nano were charged in the test column of three phase fluidized bed system. At the beginning of each run, test section was partially filled with water which prevent breakage of particles. The experiments were conducted by sequentially varying gas velocity for different volumes of nanomaterial and measuring the rate of mass transfer by collecting samples directly from the outlet ports at the top subsequently analysed by volumetric titration method. The results show enhancement in mass transfer coefficient by addition of nanomaterials. Arachitol nano has been taken in different volumes ie 3ml, 7ml, 10ml and 20ml in (GLS) gas ,liquid and solid fluidized bed with air, water and benzoic acid pellets as three phases respectively in the system. The presence of nanomaterial increases the solid liquid mass transfer coefficient value with increasing fraction of nanomaterial, increasing gas velocity and increasing time although experimental run has been taken only for one hour.

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