Toward a Better Understanding of Blast Furnace Raceway Blockages

Puttinger, Stefan; Stocker, Hugo

doi:10.1002/srin.202000227

Cited by 6 publications

(5 citation statements)

References 27 publications

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“…This shows the formation of a stagnant particle zone whose highest point lies above the tuyeres, towards the furnace wall. Such deadman shapes were found previously from DEM simulations by Natsui et al 35) and multi-fluid modelling by Jiao et al 25) The presence of such a asymmetric deadman can influence the burden descent higher upwards in the furnace shaft, 36) induce undesirable effects such as erratic burden behaviour, 36) unstable operation, 44) uneven liquid distribution, and hotspots. 25)…”

Section: Deadman Coke Flowsupporting

confidence: 66%

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

et al. 2022

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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.

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Section: Deadman Coke Flowsupporting

confidence: 66%

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

et al. 2022

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“…The impact of this can be localised hot/cold spots, which can cause damage to the furnace lining or result in variations in the rate of raw material consumption. Alternatively, it can result in erratic burden descent, causing sudden changes resulting in "hanging or slipping" of the burden [9]. Variations in these properties describe the blast furnace stability and are very important for consistent, predictable, and efficient iron production that does not cause furnace damage and prolongs its lifespan.…”

Section: Introductionmentioning

confidence: 99%

A Comparison of Laboratory Coal Testing with the Blast Furnace Process and Coal Injection

Steer

Greenslade

Marsh

2021

Metals

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The injection of coal through tuyeres into a blast furnace is widely adopted throughout the industry to reduce the amount of coke used and to improve the efficiency of the iron making process. Coals are selected depending on their availability, cost, and the physical and chemical properties determined by tests, such as the volatile matter content, fixed carbon, and ash content. This paper describes research comparing the laboratory measured properties of injection coals that were used over a two-month production period compared to the process variables and measurements of the blast furnace during that study period. In addition to the standard tests, a drop tube furnace (DTF) was used to compare the burnout of coals and the char properties against the production data using a range of statistical techniques. Linear regression modelling indicated that the coal type was the most important predictor of the coal rate but that the properties measured using laboratory tests of those coals were a minor feature in the model. However, comparisons of the Spearman’s correlations between different variables indicated that the reverse Boudouard reactivity of the chars, prepared in the DTF from the coals, did appear to be related to some extent to the coal and coke rates on production. It appears that the constant process adjustments made by the process control systems on the furnace make it difficult to identify strong correlations with the laboratory data and that the frequency of coal sampling and the coal blend variability are likely to contribute to this difficulty.

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“…In this paper, the average accuracy rate is selected as the evaluation index, and its formula is shown in Formula (8).…”

Section: Evaluation Metrics and Experimental Settingsmentioning

confidence: 99%

“…While most of China's steel industries are currently undergoing industrial reorganization and upgrading, prompt monitoring of the blast furnace tuyere condition is critical to ensure safe production and lower melting costs [1][2][3]. For many years, most steelmaking scholars have focused on the adequacy of flame combustion in the blast furnace tuyere [4], the characteristics of the blast furnace tuyere gyratory zone [5,6], blast furnace coal injection status detection [7], blast furnace raceway blockages [8], pyrolysis of coal and its interaction with coke and iron burden in a blast furnace [9], etc., there is little research on the abnormal condition detection of blast furnace tuyeres. The blast furnace operator primarily observes the blast furnace tuyere with the naked eye or through an imaging device, which cannot make a dynamic and exact judgment on the state of the tuyere [3].…”

Section: Introductionmentioning

confidence: 99%

Abnormality Detection of Blast Furnace Tuyere Based on Knowledge Distillation and a Vision Transformer

Song,

Zhang,

Wang

et al. 2023

Applied Sciences

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The blast furnace tuyere is a key position in hot metal production and is primarily observed to assess the internal state of the furnace. However, detecting abnormal tuyere conditions has relied heavily on manual judgment, leading to certain limitations. We proposed a tuyere abnormality detection model based on knowledge distillation and a vision transformer (ViT) to address this issue. In this approach, ResNet50 is employed as the Teacher model to distill knowledge into the Student model, ViT. Firstly, we introduced spatial attention modules to enhance the model’s perception and feature-extraction capabilities for different image regions. Furthermore, we simplified the depth of the ViT and improved its self-attention mechanism to alleviate training losses. In addition, we employed the knowledge distillation strategy to achieve model lightweighting and enhance the model’s generalization capability. Finally, we evaluate the model’s performance in tuyere abnormality detection and compare it with other classification methods such as VGG-19, ResNet-101, and ResNet-50. Experimental results showed that our model achieved a classification accuracy of 97.86% on a tuyere image dataset from a company, surpassing the original ViT model by 1.12% and the improved ViT model without knowledge distillation by 0.34%. Meanwhile, the model achieved a competitive classification accuracy of 90.31% and 77.65% on the classical fine-grained image datasets, Stanford Dogs and CUB-200-2011, respectively, comparable to other classification models.

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Toward a Better Understanding of Blast Furnace Raceway Blockages

Cited by 6 publications

References 27 publications

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

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

A Comparison of Laboratory Coal Testing with the Blast Furnace Process and Coal Injection

Abnormality Detection of Blast Furnace Tuyere Based on Knowledge Distillation and a Vision Transformer

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