scholarly journals Effects of BaO and B2O3 on the Absorption of Ti Inclusions for High Titanium Steel

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 165
Author(s):  
Boyang Li ◽  
Xin Geng ◽  
Zhouhua Jiang ◽  
Yu Hou ◽  
Wei Gong
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Titanium Oxide ◽  
Mold Flux ◽  
Rotating Cylinder ◽  
Experimental Results ◽  
Transfer Coefficients ◽  
Mold Fluxes ◽  
Cylinder Method

In order to study the effect of BaO or B2O3 on the absorption of Ti inclusions, the effects of mold fluxes with different contents of BaO (0~15%) or B2O3 (0~15%) on the mass transfer coefficients of TiO2 or TiN were studied with the rotating cylinder method. The experimental results show that with the addition of BaO in the mold flux, the mass transfer coefficient of TiO2 increases from 4.58 × 10−4 m/s to 6.08 × 10−4 m/s, that of TiN increases from 3.09 × 10−4 m/s to 4.41 × 10−4 m/s, 2CaO·MgO·2SiO2 is transformed into BaO·2CaO·MgO·2SiO2, and the Ti inclusions combine with CaO to form CaTiO3. With the addition of B2O3 in the mold flux, the mass transfer coefficient of TiO2 increases from 4.58 × 10−4 m/s to 7.46 × 10−4 m/s, that of TiN increases from 3.09 × 10−4 m/s to 5.50 × 10−4 m/s, CaO and B2O3 combine to 2CaO·B2O3, and Ti inclusions exist in the form of TiO2. During the experiment, TiN will be transformed into titanium oxide.

Liquid-liquid mass transfer studies in various stirred vessel designs

2015 ◽  
Vol 31 (4) ◽  
Author(s):  
Reza Afshar Ghotli ◽  
Abdul Raman Abdul Aziz ◽  
Shaliza Ibrahim
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Interfacial Area ◽  
Operating Conditions ◽  
Experimental Results ◽  
Dispersed Phase ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Wide Range

AbstractA general review on correlations to evaluate mass transfer coefficients in liquid-liquid was conducted in this work. The mass transfer models can be classified into continuous and dispersed phase coefficients. The effects of drop size and interfacial area on mass transfer coefficient were investigated briefly. Published experimental results for both continuous and dispersed phase mass transfer coefficients through different hydrodynamic conditions were considered and the results were compared. The suitability and drawbacks of these correlations depend on the operating conditions and hydrodynamics. Although the results of these models are reasonably acceptable, they could not properly predict the experimental results over a wide range of designs and operating conditions. Therefore, proper understanding of various factors affecting mass transfer coefficient needs to be further extended.

Film Cooling Downstream of a Row of Discrete Holes With Compound Angle

2000 ◽  
Vol 123 (2) ◽  
pp. 222-230 ◽  
Author(s):  
R. J. Goldstein ◽  
P. Jin
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Film Cooling ◽  
Transfer Coefficients ◽  
Cooling Effectiveness ◽  
Mass Transfer Coefficients ◽  
Cooling Performance ◽  
Film Cooling Effectiveness ◽  
Compound Angle

A special naphthalene sublimation technique is used to study the film cooling performance downstream of one row of holes of 35 deg inclination angle and 45 deg compound angle with 3d hole spacing and relatively small hole length to diameter ratio (6.3). Both film cooling effectiveness and mass/heat transfer coefficients are determined for blowing rates from 0.5 to 2.0 with density ratio of unity. The mass transfer coefficient is measured using pure air film injection, while the film cooling effectiveness is derived from comparison of mass transfer coefficients obtained following injection of naphthalene-vapor-saturated air with that of pure air injection. This technique enables one to obtain detailed local information on film cooling performance. General agreement is found in local film cooling effectiveness when compared with previous experiments. The laterally averaged effectiveness with compound angle injection is higher than that with inclined holes immediately downstream of injection at a blowing rate of 0.5 and is higher at all locations downstream of injection at larger blowing rates. A large variation of mass transfer coefficients in the lateral direction is observed in the present study. At low blowing rates of 0.5 and 1.0, the laterally averaged mass transfer coefficient is close to that of injection without compound angle. At the highest blowing rate used (2.0), the asymmetric vortex motion under the jets increases the mass transfer coefficient drastically ten diameters downstream of injection.

Dufour and Soret effects on Al2O3-water nanofluid flow over a moving thin needle: Tiwari and Das model

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Iskandar Waini ◽  
Anuar Ishak ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Skin Friction ◽  
Temporal Stability ◽  
Physical Parameters ◽  
Transfer Coefficients ◽  
Nanofluid Flow ◽  
Content Type

Purpose This paper aims to examine the effect of Dufour and Soret diffusions on Al2O3-water nanofluid flow over a moving thin needle by using the Tiwari and Das model. Design/methodology/approach The governing equations are reduced to the similarity equations using similarity transformations. The resulting equations are programmed in Matlab software through the bvp4c solver to obtain their solutions. The features of the skin friction, heat transfer and mass transfer coefficients, as well as the velocity, temperature and concentration profiles for different values of the physical parameters, are analysed and discussed. Findings The non-uniqueness of the solutions is observed for a certain range of the physical parameters. The authors also notice that the bifurcation of the solutions occurs in which the needle moves toward the origin (λ < 0). It is discovered that the first branch solutions of the skin friction coefficient and the heat transfer coefficients increase, but the mass transfer coefficient decreases in the presence of nanoparticle. Additionally, the simultaneous effect of Dufour and Soret diffusions tends to enhance the heat transfer coefficient; however, dual behaviours are observed for the mass transfer coefficient. Further analysis shows that between the two solutions, only one of them is stable and thus physically reliable in the long run. Originality/value The problem of Al2O3-water nanofluid flow over a moving thin needle with Dufour and Soret effects are the important originality of the present study. Besides, the temporal stability of the dual solutions is examined for time.

scholarly journals Correction Factors for Determining the Mass Transfer Coefficients

2021 ◽  
Vol 71 (2) ◽  
pp. 109-120
Author(s):  
Gužela Štefan ◽  
Dzianik František
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Correction Factors ◽  
Industrial Equipment ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Industrial Operations ◽  
The Given

Abstract A number of industrial operations are linked to mass transfer. The mass transfer coefficient value is necessary to know when designing the industrial equipment in which mass transfer occurs. There are various mass transfer coefficients, as well as equations for their calculation. However, the value of these coefficients determined according to these equations often has to be corrected for the given conditions. The aim of the article is to state the conversion relations - the correction factors enabling the calculation of the mass transfer coefficients values corresponding to the given conditions.

Experimental Investigation of Enhanced Absorption of Carbon Dioxide in Diethanolamine in a Microreactor

2013 ◽  
Author(s):  
Harish Ganapathy ◽  
Amir Shooshtari ◽  
Serguei Dessiatoun ◽  
Mohamed Alshehhi ◽  
Michael M. Ohadi
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Natural Gas ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Absorption Efficiency ◽  
Optimum Operating ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Liquid Absorption

Natural gas in its originally extracted form comprises carbon dioxide and hydrogen sulfide as small, but non-negligible fractions of its dominant component, methane. Natural gas in the above form is typically subjected to a sweetening process that removes these acid gases. Microscale technologies have the potential to substantially enhance mass transport phenomena on account of their inherently high surface area to volume ratio. The present work reports the mass transfer characteristics during gas-liquid absorption in a microreactor. The absorption of CO2 mixed with N2 into aqueous diethanolamine was investigated in a single straight channel having a hydraulic diameter of 762 micrometer and circular cross-sectional geometry. The performance of the reactor was characterized with respect to the absorption efficiency and mass transfer coefficient. Close to 100% absorption efficiency was obtained under optimum operating conditions. Shorter channel lengths were observed to yield enhanced values of mass transfer coefficient on account of the improved utilization of the liquid reactants’ absorption capacity for a given reactor volume. In comparison to the 0.5 m long channel, the mass transfer coefficients with the 0.3 m and 0.1 m channels were higher on an average by 35.2% and 210%, respectively. Parametric studies investigating the effects of phase superficial velocity, liquid and gas phase concentration were performed. The mass transfer coefficients achieved using the present minichannel reactor were 1–3 orders of magnitude higher than that reported using conventional gas-liquid absorption systems.

Mass Transfer Coefficient Measurement in Water/Oil/Gas Multiphase Flow

2000 ◽  
Vol 123 (2) ◽  
pp. 144-149 ◽  
Author(s):  
H. Wang ◽  
D. Vedapuri ◽  
J. Y. Cai ◽  
T. Hong ◽  
W. P. Jepson
Keyword(s):  
Mass Transfer ◽  
Multiphase Flow ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Slug Flow ◽  
Limiting Current ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Average Mass ◽  
Water Cut

Mass transfer studies in oil-containing multiphase flow provide fundamental knowledge towards the understanding of hydrodynamics and the subsequent effect on corrosion in pipelines. Mass transfer coefficient measurements in two-phase (oil/ferri-ferrocyanide) and three-phase (oil/ferri-ferrocyanide/nitrogen) flow using limiting current density technique were made in 10-cm-dia pipe at 25 and 75 percent oil percentage. Mass transfer coefficients in full pipe oil/water flow and slug flow were studied. A relationship is developed between the average mass transfer coefficient in full pipe flow and slug flow. The mass transfer coefficient decreased with a decrease of in-situ water cut. This was due to the existence of oil phase, which decreased the ionic mass transfer diffusion coefficient.

Nonparametric modeling of mass transfer coefficients for air stripping packed towers

1996 ◽  
Vol 23 (2) ◽  
pp. 549-559 ◽  
Author(s):  
Roberto M. Narbaitz ◽  
Yassine Djebbar
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Kernel Regression ◽  
Transfer Coefficients ◽  
Nonparametric Modeling ◽  
Air Stripping ◽  
Volatile Organic ◽  
Nonparametric Kernel ◽  
Nonparametric Kernel Regression

Existing parametric correlations have been found to have difficulties in predicting the removal of trace levels of volatile organic chemicals by modern air stripping towers. In this study, a new approach using a nonparametric kernel regression method was used to predict the mass transfer coefficient, KLa, of air stripping towers. Although only four variables were used, the predictions are already improved more than 50% as compared with Onda correlation, the best existing parametric correlation. The proposed technique shows a dependency of KLa on the liquid flow rate which is in good agreement with established theory. Previous parametric approaches were unable to model this relationship correctly. Key words: mass transfer coefficient, air stripping tower, volatile organic compound, nonparametric kernel regression.

Oxygen Mass Transfer Coefficients in a Three-Phase Pulsed Plate Bioreactor

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
K.V. Shetty ◽  
G. Srinikethan
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Immobilized Cells ◽  
Fixed Bed ◽  
Oxygen Mass Transfer ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Three Phase ◽  
Plate Column

Volumetric oxygen mass transfer coefficient is a decisive parameter for the selection of any contactor as an aerobic bioreactor. A pulsed plate column with fixed bed of solids in interplate spaces is a recent innovation in the field of immobilized cell bioreactors. Volumetric oxygen mass transfer coefficients are determined in a three-phase pulsed plate column involving air and water phases and with a fixed bed of glass particles, which can serve as a surface for cell immobilization packed in the interplate spaces. The volumetric mass transfer coefficients obtained in this column range from 0.067 to 0.1495 s-1 in the range of air superficial velocities from 0.011 to 0.047m/s and vibrational velocities from 0.825 to 6cm/s. Volumetric oxygen mass transfer coefficient has increased with the increase in superficial air velocity and vibrational velocity. Empirical correlation relating kLa with these variables was developed. The volumetric oxygen mass transfer coefficient values in the three-phase pulsed plate column are found to be similar or higher than the literature reported values for conventional two-phase pulsed plate columns. The values of volumetric oxygen mass transfer coefficients in the three-phase pulsed plate column are of higher order of magnitude than the literature reported values of volumetric oxygen mass transfer coefficient for many other three-phase gas-liquid-solid reactors. The pulsed plate column with fixed bed of solids is proven to have all the potential to be used as an aerobic bioreactor with immobilized cells due to its better gas-liquid mass transfer characteristics.

scholarly journals The Effect of Temperature on Solvent Recycle Process using Stripping of CO2 from MDEA, Ethylene Glycol, and Water

2021 ◽  
Vol 927 (1) ◽  
pp. 012038
Author(s):  
Aswati Mindaryani ◽  
Edia Rahayuningsih ◽  
Nikodemus Bambang Wijayanto ◽  
Alwan Naufal Masulili
Keyword(s):  
Mass Transfer ◽  
Ethylene Glycol ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flue Gas ◽  
Experimental Results ◽  
Effect Of Temperature ◽  
Gas Analyzer ◽  
Dissolved Gas

Abstract Stripping is a process to separate dissolved gas in the saturated solvent to regenerate the absorption solvent. In this study, N2 gas was used to strip dissolved CO2 gas in MDEA, ethylene glycol, and water. The experiment was conducted with three variations of temperature, namely 28°C, 35°C, and 50°C, to determine the effect of solvent’s temperature entering the stripper column on the value of the mass transfer coefficient (Kla). The stripper effluent was connected to the KANE 457 Flue Gas Analyzer to measure the concentration of CO2. Data retrievals were carried out at the 0; 30; 60; 90; 120; 150; 180th second. The experimental results show the trend of mass transfer coefficient of CO2 (Kla) is higher with the increase of solvent’s temperature entering the stripper.

scholarly journals A mass transfer heterogeneous in systems by the adsorption method

2009 ◽  
Vol 15 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Nevenka Boskovic-Vragolovic ◽  
Radmila Garic-Grulovic ◽  
Zeljko Grbavcic ◽  
Rada Pjanovic
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Fluidized Beds ◽  
Transfer Coefficients ◽  
Adsorption Method ◽  
Average Mass ◽  
Flow Past ◽  
Column Wall ◽  
Single Sphere

A mass transfer coefficient between: A liquid and single sphere and a liquid And a column wall in packed and fluidized beds of a spherical inert Particle have been studied experimentally using the adsorption method. The experiments were conducted in a column 40 mm in diameter for packed and fluidized beds, and in a two-dimensional column 140 mm?10 mm for the flow past single sphere. In all runs, the mass transfer rates were determined in the presence of spherical glass particles, 3 mm in diameter, for packed and fluidized beds. The mass transfer data were obtained by studying transfer for flow past single sphere, 20 mm in diameter. This paper discusses the possibilities of application of the adsorption method for fluid flow visualization. Local and average mass transfer coefficients were determined from the color intensity of the surface of the foils of silica gel. Correlations, Sh = f(Re) and jD = f(Re), were derived using the mass transfer coefficient data.

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