A new method for evaluating cooling capacity of blast furnace cooling stave

Understanding the heat transfer properties of the slag crust is critical to the safe operation of copper staves. The distribution of metallic iron and bubbles in the slag crust is detected by X‐ray computed tomography. The thermal conductivity of the slag crust is modified based on an effective thermal conductivity model and laser thermal conductivity measurements to predict the effect of metallic iron and bubbles on the heat transfer in the slag crust. The results show that the average volume fractions of metallic iron and air bubbles in the slag crust are 3% and 4.5%, respectively. The measured value is consistent with the trend of the effective thermal conductivity calculation model, and the calculation result of the Maxwell–Eucken effective thermal conductivity model is very accurate. Variations in the volume fraction of metallic iron in the slag crust have a greater effect on the thickness of the slag crust, while variations in the volume fraction of bubbles have a smaller effect on the thickness of the slag crust. It is recommended to keep it between 10 and 30 mm in blast furnace production to help improve the operational life of the copper stave.

Section: Methodsmentioning

confidence: 99%

X‐ray Computed Tomography Characterization of Slag Crust and the Effect of Bubbles and Metallic Iron in Slag on Heat Transfer to Copper Stave

Wang

Liu

et al. 2023

“…The use of cooling staves is one of the key measures to prolong the life of a blast furnace. [15][16][17] The cooling stave is a vital cooling device in the lining of the blast furnace, which is installed in the stack, belly, bosh, and hearth of the blast furnace. The cooling stave smoothly exports the heat transferred in the blast furnace, which can effectively protect the furnace shell from heat damage.…”

Section: Analysis Of the Reason For The Erosion Of The Wear-resistant...mentioning

confidence: 99%

Analysis of Erosion Mechanism of Wear‐Resistant Layer in Large Blast Furnace Tuyere

Zhou

Zhang

et al. 2023

The blast furnace tuyere is a crucial component for blast furnace production. The frequent damage of the copper tuyere impedes the smooth operation of the blast furnace. Welding a wear‐resistant layer on the tuyere can extend its service life, but it still falls short of the expectation in a large blast furnace. This paper aims to elucidate the erosion mechanism of the wear‐resistant layer. A scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), and an optical microscope (OM) were employed to examine the morphology, composition, and metallographic structure of the samples obtained from a 5800m3 blast furnace tuyere in China, as well as to calculate the frequency of daily slag crust shedding from cooling staves. The results indicate that the main cause of the erosion of the wear‐resistant layer is the shedding of slag crust due to the temperature fluctuation of the cooling staves. Finally, the erosion mechanism of the wear‐resistant layer is proposed. It is suggested that the formation and propagation of cracks caused by erosion of slag and hot metal are the primary failure mode of the wear‐resistant layer.This article is protected by copyright. All rights reserved.

“…The service impact of the improved copper cooling stave has to be validated further. [18][19][20] Aside from the cooling stave, another component of blast furnace cooling equipment is a copper cooling plate. Due to the expensive cost of copper cooling plates, the flaws of many holes in the blast furnace shell, and poor sealing in application, China DOI: 10.1002/srin.202300137 This work investigates the application of cooling plate in a 4500 m 3 blast furnace in China.…”

Section: Introductionmentioning

confidence: 99%

Damage Mechanism of Copper Cooling Plate on Large Blast Furnace

Gao

Zhang

et al. 2023

This paper investigates the application of cooling plate in a 4500m3 blast furnace in China. SEM‐EDS and an optical microscope were used to examine the affected area. The results demonstrate that using a cooling plate in a big blast furnace has a positive effect, notably in the belly and bosh areas, where the damage rate is less than 3%. While the cooling plates in the middle shaft are more severely damaged, with a damage rate of up to 55.40%. The majority of the copper cooling plate’s damage is centered in the water channel area, where there are furrows and numerous microcracks on the damaged surface, as well as a tiny quantity of metallurgical slag attached. Cracks form on both the inside and outside of the water channel, and the grains surrounding the cracks rise significantly, which is the primary cause of the cooling plate’s water leaking. The main factor of cooling plate damage in the early stage is wear, and the cracking caused by force in the later stage. The use of a copper cooling plate from the furnace bosh to the lower shaft is preferable to the use of a copper cooling stave.This article is protected by copyright. All rights reserved.