Analysis of factors affecting the performance of permeable bricks and optimisation measures
author: Archie
2025-03-25
These factors mainly include smelting conditions, airway size and raw material quality. Firstly, smelting conditions have a significant impact on the performance of air permeable bricks. According to the study, the surface tension and wetting angle of the liquid steel will vary under different steel grades and temperatures, which directly affects the degree of penetration of the liquid steel into the slit. Excessive superheat will lead to the reduction of liquid steel viscosity, surface tension and wetting angle, which will increase the tendency of steel penetration and reduce the ladle blow-through rate.
Analysis of factors affecting the performance of permeable bricks
1、The influence of the material of diffusion block for permeable brick
The current use of permeable brick diffusion block for vibration moulding, raw materials for 92 corundum ball, under the action of vibration, the use of corundum ball between the rolling can be shaped, the advantage of excellent permeability, but its biggest disadvantage is through the air holes are more, the amount of penetration of steel is more, it is not easy to burn open.
2, breathable brick blowing operator operation impact
Ladle use process ladle bottom blowing pipeline and ladle bottom blowing test gas pipeline there is a leakage phenomenon, the operator check, confirmation is not in place, the test flow shows qualified, the actual permeability does not meet the requirements. Permeable brick blowing process operation is not standardised, there is the phenomenon of staring at the brick core burning, due to the dispersion of permeable brick core strength than the slit-type gap is larger, blowing is too serious to cause excessive erosion of the brick core, reducing the service life of permeable bricks and bring insecurity factors.
The current use of permeable brick diffusion block for vibration moulding, raw materials for 92 corundum ball, under the action of vibration, the use of corundum ball between the rolling can be shaped, the advantage of excellent permeability, but its biggest disadvantage is through the air holes are more, the amount of penetration of steel is more, it is not easy to burn open.
2, breathable brick blowing operator operation impact
Ladle use process ladle bottom blowing pipeline and ladle bottom blowing test gas pipeline there is a leakage phenomenon, the operator check, confirmation is not in place, the test flow shows qualified, the actual permeability does not meet the requirements. Permeable brick blowing process operation is not standardised, there is the phenomenon of staring at the brick core burning, due to the dispersion of permeable brick core strength than the slit-type gap is larger, blowing is too serious to cause excessive erosion of the brick core, reducing the service life of permeable bricks and bring insecurity factors.
Measures to optimise the performance of permeable bricks
1、Material optimisation of diffuser block for permeable bricks
Through the theoretical analysis of the production of air permeable dispersible block raw materials, production process optimization adjustment, the use of 1 ~ 0.5mm, 0.6 ~ 0.2mm plate corundum instead of 92 corundum ball, which is mainly composed of alumina and chromium oxide, the content of other impurities is relatively small, especially the content of SiO2, can be reduced to less than 1%, and at the same time, the use of machine pressure molding to improve the dispersion of air permeable bricks resistance to corrosion, reduce the amount of steel seepage, and stabilize the use of dispersible blocks. Reduce the amount of steel seepage, and stabilise the use of diffuse blocks.
2、Standardise the blowing operation of permeable brick
In order to ensure the air permeable brick blowing operation, the air permeable brick blowing operation is required as follows:
1) Check whether the bottom blowing pipeline and bottom blowing hose of ladle are leaking, and deal with the leakage in time.
2) Adjust the pressure valve and flow restriction valve of the bottom blowing test gas pipeline to ensure that the pressure and flow rate before the test gas in a fixed range.
3) bottom blowing test gas metal hose inserted in the bottom of the ladle quick connector, open the valve to carry out the breathable brick blowing.
4) blowing argon flow to reach ≥ 300L / min or more, and breathable brick core darkening, the breathable brick blowing is complete and can be used, if it does not meet the requirements, the ladle shut down off-line processing;
5) Breathable bricks found late in the use of brick core erosion is serious, the depth of erosion of breathable bricks to measure, when the erosion depth ≥ 280mm must be thrown packet.
Through the theoretical analysis of the production of air permeable dispersible block raw materials, production process optimization adjustment, the use of 1 ~ 0.5mm, 0.6 ~ 0.2mm plate corundum instead of 92 corundum ball, which is mainly composed of alumina and chromium oxide, the content of other impurities is relatively small, especially the content of SiO2, can be reduced to less than 1%, and at the same time, the use of machine pressure molding to improve the dispersion of air permeable bricks resistance to corrosion, reduce the amount of steel seepage, and stabilize the use of dispersible blocks. Reduce the amount of steel seepage, and stabilise the use of diffuse blocks.
2、Standardise the blowing operation of permeable brick
In order to ensure the air permeable brick blowing operation, the air permeable brick blowing operation is required as follows:
1) Check whether the bottom blowing pipeline and bottom blowing hose of ladle are leaking, and deal with the leakage in time.
2) Adjust the pressure valve and flow restriction valve of the bottom blowing test gas pipeline to ensure that the pressure and flow rate before the test gas in a fixed range.
3) bottom blowing test gas metal hose inserted in the bottom of the ladle quick connector, open the valve to carry out the breathable brick blowing.
4) blowing argon flow to reach ≥ 300L / min or more, and breathable brick core darkening, the breathable brick blowing is complete and can be used, if it does not meet the requirements, the ladle shut down off-line processing;
5) Breathable bricks found late in the use of brick core erosion is serious, the depth of erosion of breathable bricks to measure, when the erosion depth ≥ 280mm must be thrown packet.
The stable use of ladle permeable bricks ensures the stability of the production rhythm and lays a solid foundation for the efficient production of the steel mill.
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