scholarly journals Experimental and Numerical Investigation of Reaction Behavior of Carbon Composite Briquette in Blast Furnace

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 49 ◽  
Author(s):  
Huiqing Tang ◽  
Yanjun Sun ◽  
Tao Rong
Keyword(s):  
Blast Furnace ◽  
Numerical Simulations ◽  
Numerical Study ◽  
Carbon Composite ◽  
Reaction Model ◽  
Reaction Behavior ◽  
Carbon Gasification ◽  
Reduction Of Iron ◽  
Gasification Of Carbon ◽  
Experimental Findings

The application of carbon composite briquette (CCB) is considered to be an efficient method for achieving low-energy and low-CO2-emission blast furnace (BF) operations. In this research, a combined experimental and numerical study was conducted on the CCB reaction behavior in BF. The CCB used in this study had a composition of 20.10 wt.% carbon, 29.70 wt.% magnetite, 39.70 wt.% wüstite, and 1.57 wt.% metallic iron. Using the prepared CCB samples, isotherm reduction tests under a simulated BF atmosphere (CO-CO2-N2) were conducted and a reaction model was developed. Subsequently, the reaction behavior of CCB along the mid-radial solid descending path in an actual BF of 2500 m3 was analyzed by numerical simulations based on the experimental findings and the previous results of comprehensive BF modeling. The results of the experiments showed that the CCB model predictions agreed well with the experimental measurements. With respect to the BF, the results of the numerical simulations indicated that, along the path, before the CCB temperature reached 1000 K, the CCB was reduced by CO in the BF gas; when its temperature was in the range from 1000 to 1130 K, it underwent self-reduction and contributed both CO and CO2 to the BF gas; when its temperature was above 1130 K, it only presented carbon gasification. Moreover, these results also revealed that the reduction of iron oxide and the gasification of carbon inside the CCB proceeded under an uneven mode. The uneven radial distribution of the local reduction fraction and local carbon conversion were evident in the self-reducing stage of the CCB.

Reaction model and reaction behavior of carbon composite briquette in blast furnace

2021 ◽  
Vol 377 ◽  
pp. 832-842
Author(s):  
Huiqing Tang ◽  
Yanjun Sun ◽  
Tao Rong ◽  
Zhancheng Guo
Keyword(s):  
Blast Furnace ◽  
Carbon Composite ◽  
Reaction Model ◽  
Reaction Behavior

scholarly journals Integrated Reduction of the Self–Reducing Pellets on the Blast Furnace

2020 ◽  
Vol 2,2020 (2,2020 (125)) ◽  
pp. 5-9
Author(s):  
Vaniukov A ◽  
Kovalyov D ◽  
Vaniukova N ◽  
Khodyko I ◽  
Bezshkurenko O
Keyword(s):  
Blast Furnace ◽  
Direct Reduction ◽  
Electrical Heating ◽  
Indirect Reduction ◽  
Degree Of Reduction ◽  
Reducing Gas ◽  
Reduction Of Iron ◽  
Gasification Of Carbon ◽  
Free Environment ◽  
Iron Bearing

The objective of the present work is to research a quantitate ratio of degree direct reduction inside of SRP and degree of indirect reduction outside of SRP on the top of the blast furnace.The reactions of direct and indirect reduction occurring during the heat treatment of self reducing pellets (SRP) have been studied. In this investigation Blast furnace (BF) sludge which contains particles of coke, has been included in the SRP blend as a source of solid reductant and iron bearing oxides. In the SRP as a part ot the blast furnace burden occur the reactions simultaneously: inside of SRP-direct reduction by Csolid; gasification of carbon and indirect reduction by CO; and outside of SRP-indirect reduction of iron bearing oxides by reducing gas coming from the hearth of blast furnace through the column of charged materials. The experimental setup is shown in Fig. 1. It con-sists of a electrical heating furnace, which can be moved up and down. The quartz tube passes through the furnace. The reaction zone is in the middle of the furnace. Neutral argon atmosphere is created and for indirect reduction argon changed - on hydrogen. Gases of argon, hydrogen are introduced into the furnace separately. Wire of nickel alloy chromosome joins the scales test. A thermocouple is located in the tube.The crucible of wire chrome-nickel was permeable.Metohd. The experiments was performed continuously from the start temperature (~200 ˚C) to the experimental temperature (500 ˚C; 700 ˚C; 900 ˚C; 1100 ˚C) in argon free environment. Upon reaching the desired temperature argon was replaced by hydrogen during 30 minutes. After that the reduced probe of SRP was cooled in argon. Results. The integrated degree of reduction is equal 100%, which includes 98,6 % direct reduction by solid carbon under temperatures 1100°C. The chemical analysis of the reduced SRP showed the degree of integrated reduction change from 85,79 % (900 °C) to 92,50 % (1000 °C) and 84,6% (1100°C) and metallization 83,30 % (900 °C), 89,90 % (1000 °C), 80,75 % (1100 °C).These data correspond to results of degree of reduction SRP depends on temperature

Using Ansys for Design and Numerical Study of a Specific Fixed Wing UAV

2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Unmanned Aerial Vehicle ◽  
Numerical Study ◽  
Flight Time ◽  
Cluster System ◽  
Numerical Results ◽  
Operational Performance ◽  
Gliding Flight ◽  
Aerial Vehicle ◽  
Constant Altitude

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.

scholarly journals Numerical Study and Experimental Validation of Deformation of FCC CuAl Single Crystal Obtained by Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 582
Author(s):  
Anton Y. Nikonov ◽  
Andrey I. Dmitriev ◽  
Dmitry V. Lychagin ◽  
Lilia L. Lychagina ◽  
Artem A. Bibko ◽  
...  
Keyword(s):  
Single Crystal ◽  
Numerical Study ◽  
Strain Curve ◽  
Aluminum Bronze ◽  
Partial Dislocations ◽  
Slip Planes ◽  
Loaded Material ◽  
Dislocation Movement ◽  
Dynamics Simulations ◽  
Experimental Findings

The importance of taking into account directional solidification of grains formed during 3D printing is determined by a substantial influence of their crystallographic orientation on the mechanical properties of a loaded material. This issue is studied in the present study using molecular dynamics simulations. The compression of an FCC single crystal of aluminum bronze was performed along the <111> axis. A Ni single crystal, which is characterized by higher stacking fault energy (SFE) than aluminum bronze, was also considered. It was found that the first dislocations started to move earlier in the material with lower SFE, in which the slip of two Shockley partials was observed. In the case of the material with higher SFE, the slip of a full dislocation occurred via successive splitting of its segments into partial dislocations. Regardless of the SFE value, the deformation was primarily occurred by means of the formation of dislocation complexes involved stair-rod dislocations and partial dislocations on adjacent slip planes. Hardening and softening segments of the calculated stress–strain curve were shown to correspond to the periods of hindering of dislocations at dislocation pileups and dislocation movement between them. The simulation results well agree with the experimental findings.

Vortex-Induced Vibrations of a Cylinder at Subcritical Reynolds Number

2011 ◽  
Author(s):  
Yoann Jus ◽  
Elisabeth Longatte ◽  
Jean-Camille Chassaing ◽  
Pierre Sagaut
Keyword(s):  
Reynolds Number ◽  
Numerical Simulations ◽  
Numerical Study ◽  
Damping Ratio ◽  
Experimental Studies ◽  
Cross Flow ◽  
Physical Analysis ◽  
Arbitrary Lagrangian Eulerian ◽  
Vortex Induced Vibrations ◽  
Low Mass

The present work focusses on the numerical study of Vortex-Induced Vibrations (VIV) of an elastically mounted cylinder in a cross flow at moderate Reynolds numbers. Low mass-damping experimental studies show that the dynamic behavior of the cylinder exhibits a three-branch response model, depending on the range of the reduced velocity. However, few numerical simulations deal with accurate computations of the VIV amplitudes at the lock-in upper branch of the bifurcation diagram. In this work, the dynamic response of the cylinder is investigated by means of three-dimensional Large Eddy Simulation (LES). An Arbitrary Lagrangian Eulerian framework is employed to account for fluid solid interface boundary motion and grid deformation. Numerous numerical simulations are performed at a Reynolds number of 3900 for both no damping and low-mass damping ratio and various reduced velocities. A detailed physical analysis is conducted to show how the present methodology is able to capture the different VIV responses.

ON THE APPLICATION OF A NOVEL ALGORITHM TO HYDRODYNAMIC DIFFUSION AND VELOCITY FLUCTUATIONS IN SEDIMENTING SYSTEMS

1996 ◽  
Vol 07 (04) ◽  
pp. 543-561 ◽  
Author(s):  
WOLFGANG KALTHOFF ◽  
STEFAN SCHWARZER ◽  
GERALD RISTOW ◽  
HANS J. HERRMANN
Keyword(s):  
Numerical Simulations ◽  
Numerical Method ◽  
Incompressible Fluids ◽  
Strong Anisotropy ◽  
Velocity Fluctuations ◽  
Drag Forces ◽  
Large Numbers ◽  
Spatial Dimensions ◽  
Experimental Findings ◽  
Novel Algorithm

We present a numerical method to deal efficiently with large numbers of particles in incompressible fluids. The interactions between particles and fluid are taken into account by a physically motivated ansatz based on locally defined drag forces. We demonstrate the validity of our approach by performing numerical simulations of sedimenting non-Brownian spheres in two spatial dimensions and compare our results with experiments. Our method reproduces qualitatively important aspects of the experimental findings, in particular the strong anisotropy of the hydrodynamic bulk self-diffusivities.

Preparation of high-strength biochar composite briquette for blast furnace ironmaking

2021 ◽  
Vol 118 (1) ◽  
pp. 109
Author(s):  
Zi Yu ◽  
Zhu Liu ◽  
Huiqing Tang ◽  
Qingguo Xue
Keyword(s):  
Blast Furnace ◽  
Heating Temperature ◽  
High Strength ◽  
Utilization Efficiency ◽  
Structure Evolution ◽  
Crushing Strength ◽  
Preparation Conditions ◽  
Cold Crushing Strength ◽  
Average Size ◽  
Experimental Findings

In this research, using iron-oxide fines (average size: 2.5 μm) and biochar fines (average size: 50.0 μm), the biochar composite briquette (BCB) for blast furnace (BF) application was prepared by cold briquetting followed by heat treatment. The preparing conditions were optimized regarding its cold crushing strength. Anti-pulverization capability, reaction development, and structure evolution of the optimally-designed BCB under simulated BF conditions were then examined. Results of optimizing BCB preparation conditions showed that a heating temperature of 1073 K was optimal for preparing the BCB. The optimally-designed BCB contained 11.10 wt.% carbon, 72.21 wt.% Fe3O4, 11.25 wt.% FeO, and 0.77 wt.% Fe, 6.44 wt.% gangue, and had a cold crushing strength of 1800 N/briquette. Results of BCB behavior under simulated BF conditions showed that the cold crushing strength after partial reaction of the BCB ranged from 1500 N/briquette to 5500 N/briquette and its maximum volume shrinkage degree was 0.45. The high anti-pulverization capability of the BCB was supported by the slag matrix or the iron network. Under the simulated BF conditions, the BCB underwent five stages of reduction by atmosphere, partial self-reduction and reduction by atmosphere, full self-reduction, partial self-reduction and gasification by atmosphere, and gasification by atmosphere. It is inferred from the experimental findings that, by charging the BCB in BF, an increase of top gas utilization efficiency could be realized, and a favorable influence on lowering the temperature level of the thermal reserve zone could be obtained.

Numerical Simulations of Turbulent Mixing and Autoignition of Hydrogen Fuel at Reheat Combustor Operating Conditions

2011 ◽  
Author(s):  
Elizaveta Ivanova ◽  
Berthold Noll ◽  
Peter Griebel ◽  
Manfred Aigner ◽  
Khawar Syed
Keyword(s):  
Natural Gas ◽  
Numerical Simulations ◽  
Flue Gas ◽  
Turbulent Mixing ◽  
Turbulence Modeling ◽  
Numerical Study ◽  
Operating Conditions ◽  
Fuel Blend ◽  
Flow Configuration ◽  
Modeling Methods

Turbulent mixing and autoignition of H2-rich fuels at relevant reheat combustor operating conditions are investigated in the present numerical study. The flow configuration under consideration is a fuel jet perpendicularly injected into a crossflow of hot flue gas (T > 1000K, p = 15bar). Based on the results of the experimental study for the same flow configuration and operating conditions two different fuel blends are chosen for the numerical simulations. The first fuel blend is a H2/natural gas/N2 mixture at which no autoignition events were observed in the experiments. The second fuel blend is a H2/N2 mixture at which autoignition in the mixing section occurred. First, the non-reacting flow simulations are performed for the H2/natural gas/N2 mixture in order to compare the accuracy of different turbulence modeling methods. Here the steady-state Reynolds-averaged Navier-Stokes (RANS) as well as the unsteady scale-adaptive simulation (SAS) turbulence modeling methods are applied. The velocity fields obtained in both simulations are directly validated against experimental data. The SAS method shows better agreement with the experimental results. In the second part of the present work the autoignition of the H2/N2 mixture is numerically studied using the 9-species 21-steps reaction mechanism of O’Conaire et al. [1]. As in the reference experiments, autoignition can be observed in the simulations. Influences of the turbulence modeling as well as of the hot flue gas temperature are investigated. The onset and the propagation of the ignition kernels are studied based on the SAS modeling results. The obtained numerical results are discussed and compared with data from experimental autoignition studies.

Reduction behavior of vanadium-titanium magnetite carbon composite hot briquette in blast furnace process

2019 ◽  
Vol 342 ◽  
pp. 214-223 ◽  
Author(s):  
Wei Zhao ◽  
Mansheng Chu ◽  
Hongtao Wang ◽  
Zhenggen Liu ◽  
Jue Tang ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Carbon Composite ◽  
Blast Furnace Process ◽  
Reduction Behavior ◽  
Furnace Process ◽  
Vanadium Titanium ◽  
Titanium Magnetite

A Numerical Study of Heat Transfer and Flow Structure in Channels With Miniature V Rib-Dimple Hybrid Structure on One Wall

2018 ◽  
Author(s):  
Peng Zhang ◽  
Yu Rao ◽  
Yanlin Li
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Numerical Simulations ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Hybrid Structure ◽  
Transfer Enhancement ◽  
Nusselt Numbers ◽  
Flow And Heat Transfer ◽  
Flow Mixing

This paper presents a numerical study on turbulent flow and heat transfer in the channels with a novel hybrid cooling structure with miniature V-shaped ribs and dimples on one wall. The heat transfer characteristics, pressure loss and turbulent flow structures in the channels with the rib-dimples with three different rib heights of 0.6 mm, 1.0 mm and 1.5 mm are obtained for the Reynolds numbers ranging from 18,700 to 60,000 by numerical simulations, which are also compared with counterpart of a pure dimpled and pure V ribbed channel. The results show that the overall Nusselt numbers of the V rib-dimple channel with the rib height of 1.5 mm is up to 70% higher than that of the channels with pure dimples. The numerical simulations show that the arrangement of the miniature V rib upstream each dimple induces complex secondary flow near the wall and generates downwashing vortices, which intensifies the flow mixing and turbulent kinetic energy in the dimple, resulting in significant improvement in heat transfer enhancement and uniformness.

Sign in / Sign up

Export Citation Format

Share Document