Research on Direct Reduction Dynamic Model of Carbon-Bearing Pellet Containing Zinc

2011 ◽  
Vol 214 ◽  
pp. 369-373
Author(s):  
Jing Song Wang ◽  
Xiu Wei An ◽  
Wan Hua Yu ◽  
Xue Feng She ◽  
Yin Gui Ding ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Direct Reduction ◽  
Reduction Process ◽  
Reduction Temperature ◽  
Coupled Heat Transfer ◽  
Reducing Gas ◽  
Metallization Rate ◽  
Process Factors

Base on reduction experimental data, considering the reduction process factors like carbon content, reductive removal of ZnO, changing size of pellet, and partial pressure of reducing gas, also coupled heat transfer, mass transfer and chemical reactions, a direct reduction mathematical model on carbon-bearing pellet containing zinc has been established. The reliability of the model was testified by programming and experiments. Experiments showed that, under the reduction conditions that carbon and oxygen mole ratio at 1.0 and reduction temperature 1603K, metallization rate 87% and dezincification rate 99% were observed after 15 minutes of heating.

CH4 Direct Reduction of In-Flight Fe3O4 Concentrate Particles

2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Bahador Abolpour ◽  
M. Mehdi Afsahi ◽  
Ataallah Soltani Goharrizi
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Fine Particles ◽  
Direct Reduction ◽  
Constant Heat Flux ◽  
Constant Heat ◽  
Dynamic Motion ◽  
Magnetite Ore ◽  
Model Predictions ◽  
Kinetics Of

Abstract In this study, reduction of in-flight fine particles of magnetite ore concentrate by methane at a constant heat flux has been investigated both experimentally and numerically. A 3D turbulent mathematical model was developed to simulate the dynamic motion of these particles in a methane content reactor and experiments were conducted to evaluate the model. The kinetics of the reaction were obtained using an optimizing method as: [-Ln(1-X)]1/2.91 = 1.02 × 10−2dP−2.07CCH40.16exp(−1.78 × 105/RT)t. The model predictions were compared with the experimental data and the data had an excellent agreement.

Heat Convection from a Horizontal Cylinder Rotating in a Quiescent Fluid

1986 ◽  
Vol 10 (3) ◽  
pp. 141-152
Author(s):  
H.M. Badr ◽  
S.M. Ahmed
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Horizontal Cylinder ◽  
Heat Transfer Process ◽  
Two Dimensional ◽  
Two Dimensional Flow ◽  
Boussinesq Fluid ◽  
The Mathematical Model ◽  
Quiescent Fluid

The aim of this work is a theoretical investigation to the problem of heat transfer from an isothermal horizontal cylinder rotating in a quiescent fluid. The study is based on the solution of the conservation equations of mass, momentum and energy for two-dimensional flow of a Boussinesq fluid. The effects of the parameters which influence the heat transfer process namely the Reynolds number and Grashof number are considered while the Prandtl number is held constant. Streamline and isotherm patterns are obtained from the mathematical model and the results are compared with previous experimental data. A satisfactory agreement was found.

Coupled Heat Transfer Simulation of a Low-Pressure Turbine Vane

2014 ◽  
Vol 614 ◽  
pp. 128-132 ◽  
Author(s):  
Xin Bian ◽  
Tao Li ◽  
Liang Jiang ◽  
Rui Gang Zhang ◽  
Hong Yan Huang
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Conduction Equation ◽  
Cooling Channel ◽  
Low Pressure Turbine ◽  
Coupled Heat Transfer ◽  
Turbine Vane ◽  
Heat Transfer Simulation ◽  
Transition Models ◽  
Volume Method

A coupled heat transfer (CHT) solver was established. The solver couples the N-S equations with the heat conduction equation using the finite volume method. The developed CHT solver was verified by Mark II 5411 case. The numerical results agree well with experimental data, proving the accuracy of the developed CHT code. The solver was applied to the coupled heat transfer simulations of an air-cooled turbine with a single cooling channel. Adiabatic results and CHT results were compared. Different turbulence and transition models were employed. The result shows that the developed code is of great use in engineering simulations, and in order to predict thermal loads on turbine vane accurately, transition needs to be considered.

The Dynamics of Liquid Cooling in Half-Coil Jackets

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Jayakumar Natesan Subramanian ◽  
Farouq S. Mjalli
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Liquid Temperature ◽  
Liquid Cooling ◽  
Shell Side ◽  
Stirred Vessel ◽  
Model Predictions ◽  
Temperature Dynamics ◽  
The Heat Transfer Coefficient

The heat transfer cooling of a hot liquid in a stirred vessel has been studied experimentally with coolant flowing through a half-coil around the vessel. Correlations have been developed for the heat transfer coefficient of the half coil jacket. A mathematical model for the half coil jacket liquid temperature dynamics and its analytical solution is used to find the shell side temperature profile as a function of time. It is found that the model predictions are in satisfactory agreement with the experimental data and that the developed correlation is superior to previously published correlations for similar systems.

scholarly journals Modeling of additive height and numerical analysis of cooling parameters for aero blade remanufacturing

2021 ◽  
Vol 12 (2) ◽  
pp. 803-818
Author(s):  
Miao Gong ◽  
Shijie Dai ◽  
Tao Wang ◽  
Liwen Wang
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Numerical Analysis ◽  
Cooling Effect ◽  
Transfer Model ◽  
Factors Affecting ◽  
Coupled Heat Transfer ◽  
Blade Repair ◽  
Geometric Morphology ◽  
The Mathematical Model

Abstract. Additive remanufacturing height and matching cooling parameters are the key factors affecting blade repair quality. First, the mathematical model of the single additive remanufacturing repair height and wire-feeding speed was established, the solution method was proposed and the numerical solution was obtained, and the validity of the model was verified by experiments. Then, based on the calculation results of a single additive remanufacturing repair, the geometric morphology of the cross section under double additive remanufacturing repair was analyzed, and the mathematical model was established. Second, based on the optimal parameters obtained by numerical analysis and the mathematical model, the fluid structure coupling heat transfer model of “blade fixture” for base channel cooling was established. The cooling effect of the typical section under different initial temperatures and different flow rates was calculated, and the coupled heat transfer in the process of blade remanufacturing was explained by the mechanism. Third, through the comparative analysis of the cooling effect, optimal cooling parameters of double additive remanufacturing repair were obtained, and the model of coupled heat flow was verified by experiment. The results showed that the mathematical model of additive remanufacturing height is effective for studying the thermal cycle and cooling effect of welding, and the cooling parameters obtained by numerical analysis can effectively guarantee the quality of double additive remanufacturing of blade repair.

Effects and mechanism of MgO on carbothermal reduction of Fe2TiO4

2021 ◽  
Vol 118 (4) ◽  
pp. 416
Author(s):  
Yunfei Chen ◽  
Xiangdong Xing
Keyword(s):  
Carbothermal Reduction ◽  
Thermodynamic Calculation ◽  
Direct Reduction ◽  
Reduction Temperature ◽  
Iron Particles ◽  
Promoting Effect ◽  
Effect Mechanism ◽  
Metallization Rate ◽  
High Reduction

The effects of MgO on carbothermal reduction of Fe2TiO4 had been researched including the thermodynamic calculation in this paper. And, based on XRD and SEM-EDS, the effect mechanism of MgO on the direct reduction of Fe2TiO4 had been deeply dissected, systematically. The results showed that magnesium titanium phases including MgTi2O5, MgTiO3 and Mg2TiO4 were formatted after MgO added into Fe2TiO4, which was main reason to affect the reduction of Fe2TiO4. When the MgO content in Fe2TiO4 did not exceed 2%, there was the promoting effect on the reduction of Fe2TiO4. With the increase of MgO content from 2% to 8%, the magnesium titanium phases transformed from MgTi2O5, and through MgTiO3 to Mg2TiO4. The inhibition function appeared, and can be weaken in the high reduction temperature. When reduction temperature reaches to 1300 °C, the metallization rate of F-M-8 (the reduction sample of 8% MgO) can reach 80.62% from 56.43% at 1200 °C. However, the aggregation degree of iron particles became worse when MgO was added to the sample.

scholarly journals Numerical Analysis of Radiative Heat Transfer and Direct Reduction of Three-Dimensional Multilayer Ellipsoidal Carbon-Containing Pellet Unit in the Rotary Hearth Furnace

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 994
Author(s):  
Nan Li ◽  
Feng Wang
Keyword(s):  
Heat Transfer ◽  
Removal Rate ◽  
Direct Reduction ◽  
Reduction Process ◽  
View Factor ◽  
Radiant Heat Transfer ◽  
Rotary Hearth Furnace ◽  
Reduction Degree ◽  
Hearth Furnace ◽  
Direct Reduction Process

It is very important for a multilayer pellet bed to have a proper description of the radiant heat transfer and direct reduction process in the rotary hearth furnace. Ellipsoidal pellets may also be used in industrial production. The research on this ellipsoidal pellet bed will provide comprehensive data support for the production process. Besides, the view factor is one of the important factors affecting the heat transfer of the multilayer pellet bed. It is of great significance to study its value and distribution. In this study, the effects of the gas field and the bottom of the furnace on the direct reduction of multilayer ellipsoidal pellets were considered. The local environmental viewing angle coefficient in the model was obtained through the mechanism calculation method, which is more accurate than the calculation through the radiation exchange network. Furthermore, the porosity variation in the pellet during the direct reduction process was also considered. According to the calculation, it was found that the higher initial temperature at the furnace bottom is beneficial to increase the degree of metallization (DOM) and zinc removal rate (ZRR) for all pellets, and is more advantageous to the lower pellets in the material bed. Nevertheless, the reduction degree of the lower pellets is still smaller than that of the upper pellets. The results also show that increasing the offset ξ has a greater effect on increasing the ambient view factor and each position reduction degree in the ellipsoidal pellets layer. Results can be applied for the optimization of pellets distribution in a rotary hearth furnace.

Analysis of Thermal Conduction Effects on Thermoelastic Temperature Measurements for Composite Materials

1992 ◽  
Vol 59 (3) ◽  
pp. 552-558 ◽  
Author(s):  
S. A. Dunn
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Composite Materials ◽  
Surface Stress ◽  
Thermal Conduction ◽  
Dissimilar Materials ◽  
Stress Fields ◽  
Temperature Changes ◽  
The Mathematical Model

Measurement of the temperature changes which occur as a body undergoes a change in stress is becoming a widely used technique for the analysis of surface stress fields. In this paper, an investigation into the effects of thermal conduction on surface thermoelastic temperature changes for composite materials is reported. A mathematical model which shows the effects of thermal conduction is developed, and the results from this model are compared with experimental data. The mathematical model is then extended to solve for heat transfer between two thermally dissimilar materials. It is shown how this model can be used to account for the effects of a surface epoxy layer on the observed thermoelastic temperature changes.

scholarly journals Effect of Carbon Addition on Direct Reduction Behavior of Low Quality Magnetite Ore by Reducing Gas Atmosphere

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1404
Author(s):  
Seongrim Song ◽  
Youngjo Kang
Keyword(s):  
Direct Reduction ◽  
Reduction Process ◽  
Hydrocarbon Fuel ◽  
Carbon Composite ◽  
Direct Reduced Iron ◽  
Carbon Efficiency ◽  
Reducing Gas ◽  
Initial Reduction ◽  
Coal Particles ◽  
Composite Pellets

Recently, direct reduced iron (DRI) has been highlighted as a promising iron source for electric arc furnace (EAF)-based steelmaking. The two typical production methods for DRI are gas-based reduction and reduction using carbon composite pellets. While the gas-based reduction is strongly dependent on the reliable supply of hydrocarbon fuel, reduction using ore-coal composite pellets has relatively low productivity due to solid–solid reactions. To overcome the limitations of the above two processes, and to achieve a more efficient direct reduction process of iron ore, the possibility of combining these two methods was investigated. The experiments focused on performing an initial direct reduction using ore-coal composite pellets followed by a second stage gas reduction. It was assumed that the initial reduction of the carbon composite pellets would enhance the efficiency of the subsequent reduction by gas and the total reduction efficiency. The porosity, as well as the carbon efficiency for direct reduction, were measured to determine the optimal conditions for the initial reduction, such as the size ratio of ore and coal particles. Thereafter, further reduction by the reducing gas was carried out to verify the effect of the preliminary reduction. The reduction kinetics of the reducing gas was also discussed.

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