Numerical Analysis on the Refractory Wear of the Blast Furnace Main Trough

2014 ◽  
Vol 92 ◽  
pp. 294-300 ◽  
Author(s):  
Ca Min Chang ◽  
Yon Sen Lin ◽  
Chien Nan Pan ◽  
Wen Tung Cheng
Keyword(s):  
Shear Stress ◽  
Blast Furnace ◽  
Erosion Rate ◽  
Three Dimensional ◽  
Stress Profile ◽  
Refractory Wear ◽  
Main Trough ◽  
Split Operator ◽  
Shear Stress Profile ◽  
Volume Method

This study aims to numerically analyze the refractory wear of the blast furnace main trough. The three dimensional transient Navier-Stocks equation associated with the volume of fluid (VOF) was developed to describe the flow fields of air, molten iron and slag in the main trough of the blast furnace during tapping process; and then solved by the finite volume method (FVM) subject to the pressure implicit with split operator (PSIO). Based on the Newton’s law of viscosity, the computed shear stress profile in the impingement region consists with the erosion rate of main trough from the no. 4 blast furnace at China Steel Corporation (CSC BF4). The influence of the tapping angle and the ratio of iron to slag in tapping stream on the wall shear stress of main trough was also examined for the suggestion to minimize the refractory wear of blast furnace main trough in this work.

scholarly journals Numerical Analysis on Flow Behavior of Molten Iron and Slag in Main Trough of Blast Furnace during Tapping Process

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Li Wang ◽  
Chien-Nan Pan ◽  
Wen-Tung Cheng
Keyword(s):  
Blast Furnace ◽  
Separation Efficiency ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Molten Iron ◽  
Three Dimensional Model ◽  
Operation Conditions ◽  
Main Trough ◽  
Iron Losses ◽  
Volume Method

The three-dimensional model was developed according to number 4 of the main trough of blast furnace at China Steel Co. (CSC BF4). The k-ε equations and volume of fluid (VOF) were used for describing the turbulent flow at the impinging zone of trough, indicating fluids of liquid iron, molten slag, and air in the governing equation, respectively, in this paper. The pressure field and velocity profile were then obtained by the finite volume method (FVM) and the pressure implicit with splitting of operators (PISO), respectively, followed by calculating the wall shear stress through Newton’s law of viscosity for validation. Then, the operation conditions and the main trough geometry were numerically examined for the separation efficiency of iron from slag stream. As shown in the results, the molten iron losses associated with the slag can be reduced by increasing the height difference between the slag and iron ports, reducing the tapping rate, and increasing the height of the opening under the skimmer.

scholarly journals Numerical Analysis on Velocity and Temperature of the Fluid in a Blast Furnace Main Trough

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 249
Author(s):  
Yao Ge ◽  
Meng Li ◽  
Han Wei ◽  
Dong Liang ◽  
Xuebin Wang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Blast Furnace ◽  
Wall Shear Stress ◽  
Molten Slag ◽  
Three Dimensional ◽  
Furnace Process ◽  
Main Trough ◽  
Mechanical Erosion ◽  
Wall Shear ◽  
Fourier Equation

The main trough is a part of the blast furnace process for hot metal and molten slag transportation from the tap hole to the torpedo, and mechanical erosion of the trough is an important reason for a short life of a campaign. This article employed OpenFoam code to numerically study and analyze velocity, temperature and wall shear stress of the fluids in the main trough during a full tapping process. In the code, a three-dimensional transient mass, momentum and energy conservation equations, including the standard k-ε turbulence model, were developed for the fluid in the trough. Temperature distribution in refractory is solved by the Fourier equation through conjugate heat transfer with the fluid in the trough. Change velocities of the fluid during the full tapping process are exactly described by a parabolic equation. The investigation results show that there are strong turbulences at the area of hot metal’s falling position and the turbulences have influence on velocity, temperature and wall shear stress of the fluid. With the increase of the angle of the tap hole, the wall shear stress increases. Mechanical erosion of the trough has the smallest value and the campaign of the main trough is estimated to expand over 5 days at the tap hole angle of 7°.

Shear-Stress Profile along a Cell Focal Adhesion

2006 ◽  
Vol 18 (12) ◽  
pp. 1537-1540 ◽  
Author(s):  
D. Raz–Ben Aroush ◽  
H. D. Wagner
Keyword(s):  
Shear Stress ◽  
Focal Adhesion ◽  
Stress Profile ◽  
Shear Stress Profile ◽  
A Cell

scholarly journals Impaired handgrip exercise-induced brachial artery flow-mediated dilation in young obese males

2016 ◽  
Vol 41 (5) ◽  
pp. 528-537 ◽  
Author(s):  
David J. Slattery ◽  
Troy J.R. Stuckless ◽  
Trevor J. King ◽  
Kyra E. Pyke
Keyword(s):  
Shear Stress ◽  
Brachial Artery ◽  
Reactive Hyperemia ◽  
Obese Group ◽  
Stress Profile ◽  
Flow Mediated Dilation ◽  
Handgrip Exercise ◽  
Brachial Artery Diameter ◽  
Shear Stress Profile ◽  
Forearm Occlusion

Flow mediated dilation (FMD) stimulated by different shear stress stimulus profiles may recruit distinct transduction mechanisms, and provide distinct information regarding endothelial function. The purpose of this study was to determine whether obesity influences brachial artery FMD differently depending on the shear stress profile used for FMD assessment. The FMD response to a brief, intermediate, and sustained shear stress profile was assessed in obese (n = 9) and lean (n = 19) young men as follows: brief stimulus, standard reactive hyperemia (RH) following a 5 min forearm occlusion (5 min RH); intermediate stimulus, RH following a 15 min forearm occlusion (15 min RH); sustained stimulus, 10 min of handgrip exercise (HGEX). Brachial artery diameter and mean shear stress were assessed using echo and Doppler ultrasound, respectively, during each FMD test. There was no group difference in HGEX shear stress (p = 0.390); however, the obese group had a lower HGEX-FMD (5.2 ± 3.0% versus 11.5 ± 4.4%, p < 0.001). There was no group difference in 5 min RH-FMD (p = 0.466) or 15 min RH-FMD (p = 0.181); however, the shear stress stimulus was larger in the obese group. After normalization to the stimulus the 15 min RH-FMD (p = 0.002), but not the 5 min RH-FMD (p = 0.118) was lower in the obese group. These data suggest that obesity may have a more pronounced impact on the endothelium’s ability to respond to prolonged increases in shear stress.

scholarly journals Numerical Analysis on Erosion and Optimization of a Blast Furnace Main Trough

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4851
Author(s):  
Hao Yao ◽  
Huiting Chen ◽  
Yao Ge ◽  
Han Wei ◽  
Ying Li ◽  
...  
Keyword(s):  
Blast Furnace ◽  
High Efficiency ◽  
Low Cost ◽  
Continuous Production ◽  
Hot Metal ◽  
Main Trough ◽  
Impact Position ◽  
Refractory Life ◽  
Volume Method ◽  
The Impact

The main trough of a blast furnace (BF) is a main passage for hot metal and molten slag transportation from the taphole to the torpedo and the slag handling. Its appropriate working status and controlled erosion ensure a safe, stable, high-efficiency and low-cost continuous production of hot metal. In this work, the tapping process of a main trough of a BF in the east of China was numerically studied with the help of a CFD library written in C++, called OpenFOAM, based on the use of the Finite Volume Method (FVM). The results show that turbulence intensity downstream of the hot metal impact position becomes weaker and the turbulence area becomes larger in the main trough. During the tapping, thermal stress of wall refractory reaches the maximum value of 1.7 × 107 Pa at the 4 m position in the main trough. Furthermore, baffles in the main trough placed between 5.8 m and 6.2 m were found to control and reduce the impact of the turbulence on the refractory life. The metal flowrate upstream of the baffles can be decreased by 6%, and the flow velocity on the upper sidewall and bottom wall decrease by 9% and 7%, respectively, compared with the base model. By using baffles, the minimum fatigue life of the refractory in the main trough increases by 15 tappings compared with the base model, so the period between the maintenance stops can be prolonged by about 2 days.

Streamwise development of turbulent boundary-layer drag reduction with polymer injection

2008 ◽  
Vol 597 ◽  
pp. 31-66 ◽  
Author(s):  
Y. X. HOU ◽  
V. S. R. SOMANDEPALLI ◽  
M. G. MUNGAL
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Turbulent Boundary Layer ◽  
Drag Reduction ◽  
Reynolds Shear Stress ◽  
Depletion Region ◽  
Stress Profile ◽  
Total Stress ◽  
Polymer Injection ◽  
Shear Stress Profile

Zero-pressure-gradient turbulent boundary-layer drag reduction by polymer injection has been studied with particle image velocimetry. Flow fields ranging from low to maximum drag reduction have been investigated. A previously developed technique – the (1 − y/δ) fit to the total shear stress profile – has been used to evaluate the skin friction, drag reduction and polymer stress. Current results agree well with the semi-log plot of drag reduction vs. normalized polymer flux which has been used by previous workers and can be used as a guide to optimize the use of polymer from a single injector. Detailed flow-field statistics show many special features that pertain to polymer flow. It is shown that the mean velocity responds quickly to the suddenly reduced wall shear stress associated with polymer injection. However, it takes a much longer time for the entire Reynolds shear stress profile to adjust to the same change. The Reynolds shear stress profiles in wall units can be higher than unity and this unique feature can be used to further judge whether the flow is in equilibrium. The streamwise evolution of drag reduction magnitude is used to divide the flow into three regions: development region; steady-state region; and depletion region. The polymer stress is estimated and found to be proportional to drag reduction in the depletion region, but not necessarily so in the other regions. The interaction between injected polymer and turbulent activity in a developing boundary-layer flow is dependent upon the flow history and it produces an equally complex relationship between polymer stress and drag reduction. The stress balance in the boundary layer and the dynamical contribution of the various stresses to the total stress are evaluated and it is seen that the polymer stresses can account for up to 25% of the total stress. This finding is in contrast to channel flows with homogeneous polymer injection where the polymer stress is found to account for up to 60% of the total stress.

Marangoni effects caused by contaminants adsorbed on bubble surfaces

2010 ◽  
Vol 647 ◽  
pp. 143-161 ◽  
Author(s):  
PETER LAKSHMANAN ◽  
PETER EHRHARD
Keyword(s):  
Surface Tension ◽  
Shear Stress ◽  
Contaminant Transport ◽  
Level Set ◽  
Solid Sphere ◽  
Bubble Surface ◽  
Stress Profile ◽  
Air Bubbles ◽  
Shear Stress Profile ◽  
Marangoni Effects

The influence of Marangoni stresses, caused by contaminants adsorbed on the surface of small air bubbles, rising in water, is examined by numerical simulations. A modified level set method is used to represent the deformable bubble interface, extended by a model for the contaminant transport on the bubble surface. We show that surface tension variations of less than 2% are sufficient to generate Marangoni stresses that are strong enough to change the rising characteristics of a bubble to that of a corresponding solid particle. In such situations, we find that the bubble surface is fully covered with contaminant and the shear stress profile resembles the shear stress profile around a solid sphere.

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