Analysis of the Coke Particle Size Distribution and Porosity of Deadman Based on Blast Furnace Hearth Dissection

Niu, Qun; Cheng, Shusen; Xu, Wenxuan; Niu, Weijun; Mei, Yaguang

doi:10.2355/isijinternational.isijint-2019-253

Cited by 17 publications

(10 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The deadman coke particle size and distribution of the hearth cokes were consistent with the results of the previous studies. Niu et al 25 found that the percentage of hearth particle size of <25 and 25−40 mm were relatively large, and the average size of hearth coke was about 20−31 mm. Zhang et al 3 also found similar particle size distributions and proposed the average hearth coke sizes of the horizontal samples and vertical samples were 28.04 and 30.55 mm, respectively.…”

Section: Discussion and Analysismentioning

confidence: 99%

Graphitization and Performance of Deadman Coke in a Large Dissected Blast Furnace

et al. 2021

View full text Add to dashboard Cite

The graphitization and performance of deadman coke in the blast furnace hearth have an essential influence on the longevity of the blast furnace. In this paper, coke samples were obtained from various heights in a hearth during the overhaul of the blast furnace. The voidage, particle size, graphitization degree, microstructure, and structure evolution of multiple cokes were analyzed through digital image processing, XRD, Raman spectra, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDS). The graphitization results were compared with feed coke, tuyere coke, cohesive zone coke, and deadman coke in reference, and the main findings were analyzed. The following results were obtained. First, the voidage of deadman coke increased and then decreased with the increase of the depth while the particle size continued to decrease. In addition, the consumption rate of coke as a carburizer, reductant, and heart source was 8.47, 30.95, and 60.58%, respectively. Second, the graphitization degree of deadman coke was extremely high and showed a trend of first increasing and then decreasing. Finally, the evolution mechanism of coke graphitization was proposed. Molten iron, alkali metal, temperature, and mineral were the crucial factors that affect the graphitization of coke. The turning point of the graphitization degree was related to the buoyancy of the hearth.

show abstract

Section: Discussion and Analysismentioning

confidence: 99%

Graphitization and Performance of Deadman Coke in a Large Dissected Blast Furnace

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In the calculation model, a round, table-shaped deadman was assumed to be in the center of the hearth, as shown in Figure 2b. It was set as a porous medium with a porosity of 0.3 [20][21][22][23]. The porous medium model was used to reflect the effect of the deadman on the flow of the molten iron.…”

Section: Physical Modelsmentioning

confidence: 99%

“…→ g is the acceleration of gravity; S i is the source terms of the momentum equation; µ is the viscosity; 1/α is the viscous resistance coefficient; d c is the average diameter of the coke constituting the deadman, which is taken as 0.03 m [23]; C is the inertial resistance coefficient.…”

Section: Mathematical Expression Of the Deadmanmentioning

confidence: 99%

Numerical Simulation Model for Evaluating Protection Measures of Blast Furnace Hearth

Wang

Chen

et al. 2022

Processes

View full text Add to dashboard Cite

The blast furnace (BF) hearth is critical for determining the life of a BF. Irreversibly eroded hearths can be caused by high-temperature molten iron erosion, alkali metal corrosion, and thermal stress. When serious depression erosion occurs in the hearth, furnace protection measures can prevent the erosion from expanding and ensure the safe operation of the BF. At present, furnace protection measures and furnace protection strength are mostly selected based on engineering experience. In this paper, a three-dimensional (3D) computational fluid dynamics (CFD) numerical model of BF hearth with elephant-type depression erosion was established to predict and evaluate the effect of furnace protection measures. At the same time, the phase change behavior of hot iron solidification was also considered. A numerical model was used to analyze common furnace protection measures such as increasing furnace hearth cooling, closing the tuyere, reducing the tapping productivity, and reducing the tapping temperature. The calculation results are consistent with actual furnace protection experience.

show abstract

“…More recently, Niu, Kexin and Zhang et al 29,38,61,62) conducted dissection studies on multiple Chinese commercial blast furnaces. Their observations mainly included particle size and porosity distributions within the deadman, which provide important information on the local permeability of the bed.…”

Section: Blast Furnace Dissectionmentioning

confidence: 99%

“…The deadman porosity in the centre of the bed is found to lie between 0.25 and 0.4, as was previously found from blast furnace dissection studies. 29,38) A slight increase of porosity is found approaching both the more actively flowing top and the bottom of the deadman, where a larger part of the burden weight has been transferred to the hearth walls and particle-particle contact forces are decreased. As was discussed previously, this effect is amplified by overlapping particle volume found in the soft sphere approach.…”

Section: Deadman Porositymentioning

confidence: 99%

Large-scale VOF/CFD-DEM Simulation of Blast Furnace Hearth Dynamics

et al. 2022

View full text Add to dashboard Cite

In this work, large-scale simulations of the blast furnace hearth are presented, conducted using a model combining Computational Fluid Dynamics, the Volume of Fluid method, and the Discrete Element Method. Using a 5 m diameter, full-3D geometry, the influence of burden weight, bi-disperse packing, and blocked tuyeres on the liquid and solids flow within the hearth are investigated. Horizontal and vertical porosity profiles are presented, and the influence of the dynamic liquid level on the state of the deadman is evaluated. The liquid iron flow during tapping is visualised, and the influence of a coke-free space on the flow pattern is analysed. The magnitude of the circumferential flow through the corner of the hearth is analysed, and found to decrease with increasing burden weight pressure and coke diameter in the bed centre. A significant influence of the dynamic deadman on the liquid flow pattern is found, especially in case of a floating deadman. In addition to the liquid flow, the solid coke flow towards the raceways is analysed. Two pathways for coke particles towards the raceway are uncovered, one path through the actively flowing layer above the deadman, and a second path moving through the deadman and entering the raceways from below. The balance between these two mechanisms was found to change during the tapping cycle. Lastly, implementations for heat and dissolved carbon mass transfer are presented, and demonstrated using a full-scale 10 m hearth simulation. Additional closures for heat and mass transfer rates are required, but the current model is found in good shape for future work.

show abstract

Analysis of the Coke Particle Size Distribution and Porosity of Deadman Based on Blast Furnace Hearth Dissection

Cited by 17 publications

References 15 publications

Graphitization and Performance of Deadman Coke in a Large Dissected Blast Furnace

Graphitization and Performance of Deadman Coke in a Large Dissected Blast Furnace

Numerical Simulation Model for Evaluating Protection Measures of Blast Furnace Hearth

Large-scale VOF/CFD-DEM Simulation of Blast Furnace Hearth Dynamics

Contact Info

Product

Resources

About