Blast furnace body repairing construction method

Abstract

The invention belongs to the technical field of blast furnace repair, and mainly relates to a blast furnace body repair construction method which is characterized by comprising hearth cleaning and hearth repair, (1) hearth cleaning comprises blast furnace air supply stopping and residual iron discharging; a slagging-off door is formed, and original tuyere combined bricks and annular carbon of the hearth are cleaned and removed downwards from a tuyere to the surface of a cooling wall after entering the furnace; (2) repairing the furnace hearth, repairing furnace bottom carbon bricks by using a hearth castable; new ring carbon is built, and high-thermal-conductivity castable is poured between carbon bricks of the ring carbon and the cooling wall; pouring furnace bottom and hearth castable to the tuyere; and baking the furnace. The repairing problem that the refractory needs to be thoroughly dismantled when not being used is solved, and low efficiency of a traditional full dismantling scheme is avoided by improving the refractory structure and the construction method; construction safety is guaranteed, and the construction period is greatly shortened; and refractory materials are reasonably utilized, the structure is improved, the overhaul cost and the later maintenance difficulty are reduced, and remarkable economic benefits are created.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace repair technology, and particularly relates to a blast furnace body repair construction method. Background Technology

[0002] The existing refractory repair of the blast furnace hearth is mainly divided into two categories: complete removal and restoration of the hearth refractory to its original state, and retention of the hearth refractory for casting repair using castable refractory.

[0003] The approach of "completely removing and restoring the hearth refractory materials to their original state" presents several drawbacks, including an excessively long maintenance cycle. Traditional methods of lining or replacing carbon bricks typically require more than 20 days, and even longer before the development of integral casting repair technology for large blast furnace hearths. This not only severely impacts the blast furnace's operating rate but also significantly increases the substantial economic losses caused by production stoppages. Furthermore, this method is intensive and costly, requiring furnace shutdown and thorough hearth cleaning, resulting in higher material and labor costs. Additionally, the dismantling process carries the risk of secondary damage to undamaged carbon bricks and fails to fully utilize remaining usable refractory materials, leading to resource waste.

[0004] While the technique of "retaining refractory and using castable for repair" demonstrates advantages in shortening the construction period, it still faces a series of technical challenges. "Retaining refractory and using castable for repair" is only suitable for scenarios where refractory is available. The quality of the castable repair largely depends on the properties of the castable itself, such as high-temperature resistance, erosion resistance, scour resistance, and quick-drying and explosion-proof characteristics, as well as the precision of on-site construction control. If there is insufficient compaction between the castable and the remaining carbon bricks, or between the castable and the cooling wall, thermal gaps will form, hindering normal heat conduction in the hearth and creating safety hazards. Furthermore, after castable repair, the interfacial bonding effect between the castable and the original furnace lining refractory material, the stress concentration problems that may arise due to differences in thermal expansion coefficients, and the durability and reliability of the repaired area during long-term operation are all important considerations.

[0005] Therefore, there is room for improvement in both of these mainstream maintenance methods in terms of efficiency, cost control, technical reliability, and long-term performance. Summary of the Invention

[0006] To address the above problems, this invention combines the two maintenance schemes mentioned above and proposes a blast furnace body repair construction method that can efficiently complete the hearth maintenance task in a short period of time and continue to maintain the stable production operation of the blast furnace for a long time.

[0007] This application proposes a method for repairing a blast furnace body, characterized by comprising:

[0008] S01 furnace hearth cleaning includes the following steps:

[0009] S011. Blast furnace stops blowing air and discharges residual iron;

[0010] S012. Open the slag removal door and enter the furnace to clean and remove the original tuyer brick assembly and ring carbon from the tuyer downwards to the surface of the cooling wall.

[0011] S02 furnace hearth repair includes the following steps;

[0012] S021. Repair the carbon bricks at the bottom of the furnace with hearth castable;

[0013] S022. Construct a new ring of carbon bricks and pour high thermal conductivity castable between the carbon bricks and the cooling wall of the ring of carbon bricks.

[0014] S023, pour the furnace bottom and hearth refractory material up to the tuyeres;

[0015] S024, Oven.

[0016] Furthermore, the annular carbon is a carbon brick with a length of 600-800 mm.

[0017] Furthermore, the annular carbon area being constructed is located between the furnace bottom and the tuyeres of the hearth, and the hearth castable is poured into the furnace bottom and the annular carbon area and the tuyeres portion, forming the outermost layer of the hearth wall.

[0018] Furthermore, in step S012, the slag removal gate is located at the taphole of the furnace hearth, and the excavator enters the furnace through the slag removal gate to clean the slag and the remaining residual iron.

[0019] Furthermore, in step S022, the annular carbon area of ​​the furnace hearth needs to be ground and leveled before the annular carbon is laid.

[0020] Furthermore, in step S022, the ring carbon brick masonry and the casting of the high thermal conductivity castable are carried out layer by layer according to the carbon brick masonry.

[0021] Furthermore, S022 also includes a transport vehicle for lining the charcoal bricks on the top of the blast furnace.

[0022] Furthermore, a winch is installed on the furnace top as a transport tool for the charcoal bricks, and the winch is fixed to the furnace platform through a water-drilling hole on the furnace top.

[0023] Furthermore, step S022 also includes removing two of the large tuyeres along the diameter of the furnace hearth to serve as transport tracks for the charcoal bricks, the transport tracks being located on the platforms inside and outside the tuyeres.

[0024] Furthermore, step S023 also includes filling the taphole completely with the furnace wall casting material during furnace wall casting.

[0025] The beneficial effects of this invention are as follows: it solves the problem of complete dismantling when refractory materials cannot be used, and avoids the inefficiency of traditional complete dismantling schemes by improving the refractory material structure and construction methods and combining the advantages of these two schemes; it ensures construction safety and significantly shortens the construction period; and it makes reasonable use of refractory materials and improves the structure, reducing maintenance costs and the difficulty of later maintenance, thus creating significant economic benefits. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic flowchart illustrating a blast furnace body repair construction method provided in this application embodiment;

[0028] Figure 2 A schematic diagram of the hearth structure in a blast furnace body repair construction method provided in this application embodiment;

[0029] Figure 3 A schematic diagram of the refractory material structure of the hearth in a blast furnace body repair construction method provided in this application embodiment;

[0030] Figure 4-11 This application provides an example diagram of hearth repair in a blast furnace body repair construction method.

[0031] 1. Hearth; 11. Bottom of the furnace; 12. New ring coal; 13. Tubular outlet; 14. Tap hole; 15. Slag removal door; 16. Cooling wall; 17. Transport track; 18. Water hole; 2. Coal brick; 21. Bottom coal brick; 22. Ring coal brick; 3. High thermal conductivity castable; 4. Hearth castable. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other implementations obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. In the various drawings, the same elements are represented by the same or similar reference numerals, and for clarity, the various parts in the drawings are not drawn to scale.

[0033] See Figure 1-4As shown, this invention proposes a method for repairing a blast furnace body, characterized by comprising:

[0034] S01 furnace hearth cleaning includes the following steps:

[0035] S011. Blast furnace stops blowing air and discharges residual iron;

[0036] S012. Open the slag removal door 15 and enter the furnace to clean and remove the original tuyer combination bricks and ring carbon 12 from the tuyer 13 down to the surface of the cooling wall.

[0037] S02 furnace hearth repair includes the following steps;

[0038] S021. Repair the furnace bottom carbon bricks 21 with hearth casting refractory;

[0039] S022, Construct the new ring carbon 12, and pour high thermal conductivity castable between the new ring carbon brick 22 and the cooling wall 16;

[0040] S023, pour the furnace bottom and hearth refractory material up to the tuyeres;

[0041] S024, Oven.

[0042] Specifically, in step S012, the slag removal gate 15 is located at the iron tap 14 of the furnace hearth. The excavator enters the furnace through the slag removal gate 15 to clean the slag and the remaining residual iron.

[0043] See Figure 2 , 3 As shown, specifically, in step S022, the annular carbon area of ​​the furnace hearth needs to be ground and leveled before laying the new annular carbon 12; the high thermal conductivity castable between the new annular carbon 12 and the cooling wall 16 is poured layer by layer according to the carbon bricks. Specifically, the annular carbon area where the new annular carbon is laid is located between the furnace bottom 11 and the tuyeres 13 of the furnace hearth. In this embodiment, the new annular carbon 12 is laid in two layers, which are along the diameter direction of the inner wall of the furnace hearth 1. Preferably, the annular carbon bricks 22 are carbon bricks with a length of 600-800mm to ensure a compact structure. When pouring the high thermal conductivity castable, the gap between the annular carbon bricks 22 and the cooling wall 16 needs to be filled evenly to ensure heat transfer efficiency.

[0044] See Figure 2As shown, specifically, step S022 also includes installing a transport vehicle for charcoal brick laying on the top of the blast furnace. Specifically, a winch is installed on the top of the furnace as the transport vehicle for charcoal brick laying, and the winch is fixed to the furnace platform through a water-drilling hole 18 on the top of the furnace. Specifically, step S022 also includes removing two large sets of tuyeres 13 along the diameter direction of the hearth to serve as charcoal brick transport tracks 7, which are located on the inner and outer platforms of the tuyeres 13.

[0045] Specifically, step S023 further includes filling the taphole 15 completely with the furnace hearth casting material during the hearth casting process; the furnace hearth casting material is poured into the furnace bottom of the hearth and the ring carbon and tuyeres, forming the innermost furnace wall of the hearth, restoring the original furnace shape.

[0046] The overall refractory structure design of the hearth described in this application is as follows: the hearth is constructed with carbon bricks of a custom length of 600-800mm for the annular carbon layer; the annular carbon layer extends from above the furnace bottom to below the tuyeres, and high thermal conductivity castable is used to fill the space between the annular carbon bricks and the cooling wall; the inner side of the hearth is restored to its original shape using hearth castable, and the hearth castable completely covers the inner wall of the hearth, including the furnace bottom, the annular carbon layer, and the tuyeres, all of which are cast with hearth castable to restore the original shape of the hearth.

[0047] This invention has significant advantages and positive effects, mainly reflected in three aspects:

[0048] I. Overcoming Limitations and Achieving High Efficiency and Adaptability. Existing technologies suffer from long construction periods and high costs for the "complete dismantling and restoration" approach, while the "retaining refractory material and casting repair" approach is only applicable to scenarios where refractory materials can be reused, exhibiting clear limitations in its applicability. This application integrates these two approaches, solving the repair challenge of complete dismantling when refractory materials cannot be reused. Furthermore, by improving the refractory material structure and construction methods, it avoids the inefficiency of traditional full dismantling solutions, providing a new path for short-term blast furnace maintenance and commissioning.

[0049] Second, it ensures construction safety and significantly shortens the construction period. The reliable construction technology provided by this patent not only standardizes the construction process and strengthens safety management, but also optimizes the connection between refractory material removal and reconstruction pouring, effectively shortening the construction cycle and solving the pain points of traditional maintenance being "time-consuming and high-risk". This ensures the smooth progress of maintenance tasks and lays the foundation for the rapid restoration of stable production of the blast furnace.

[0050] Third, it generates significant economic benefits. By shortening the maintenance period, blast furnaces can resume production more quickly, reducing downtime losses. Simultaneously, the rational use of refractory materials and structural improvements reduce maintenance costs and the difficulty of subsequent maintenance. Based on the actual production situation of steel enterprises, this solution directly helps them improve production efficiency and control costs, creating substantial economic value.

[0051] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be noted that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. The specific meaning of the above terms can be understood according to the specific circumstances.

[0052] It should be noted that the above embodiments are illustrative of this disclosure and not restrictive, and that alternative embodiments can be devised by those skilled in the art without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This disclosure can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several systems, several of these systems can be embodied by the same item of hardware.

[0053] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for repairing a blast furnace body, characterized in that, include: S01 furnace hearth cleaning includes the following steps: S011. Blast furnace stops blowing air and discharges residual iron; S012. Open the slag removal door and enter the furnace to clean and remove the original tuyer brick assembly and ring carbon from the tuyer downwards to the surface of the cooling wall. S02 furnace hearth repair includes the following steps; S021. Repair the carbon bricks at the bottom of the furnace with hearth castable; S022. Construct a new ring of carbon bricks and pour high thermal conductivity castable between the carbon bricks and the cooling wall of the ring of carbon bricks. S023, pour the furnace bottom and hearth refractory material up to the tuyeres; S024, Oven.

2. The blast furnace body repair construction method according to claim 1, characterized in that, The new ring carbon is a carbon brick with a length of 600-800 mm.

3. The blast furnace body repair construction method according to claim 1, characterized in that, The annular carbon region for constructing the new annular carbon is located between the furnace bottom and the tuyeres of the hearth. The hearth castable is poured into the furnace bottom and the annular carbon and tuyeres portion of the hearth, forming the outermost layer of the hearth wall.

4. The blast furnace body repair construction method according to claim 1, characterized in that, In step S012, the slag removal gate is located at the taphole of the furnace hearth. The excavator enters the furnace through the slag removal gate to clean up the slag and the remaining residual iron.

5. The blast furnace body repair construction method according to claim 1, characterized in that, In step S022, the annular carbon area of ​​the furnace hearth needs to be ground and leveled before the new annular carbon is laid.

6. The blast furnace body repair construction method according to claim 1, characterized in that, In step S022, the ring carbon brick masonry and the casting of the high thermal conductivity castable are carried out layer by layer according to the carbon brick masonry.

7. The blast furnace body repair construction method according to claim 1, characterized in that, Step S022 also includes arranging a transport vehicle for charcoal brick lining on the top of the blast furnace.

8. The blast furnace body repair construction method according to claim 7, characterized in that, The winch installed on the furnace top serves as the transport tool for the charcoal bricks. The winch is fixed to the furnace platform through the water-drilling hole on the furnace top.

9. The blast furnace body repair construction method according to claim 8, characterized in that, In step S022, two of the large tuyeres are removed along the diameter of the furnace hearth to serve as transport tracks for the charcoal bricks. The transport tracks are located on the platforms inside and outside the tuyeres.

10. The blast furnace body repair construction method according to claim 1, characterized in that, Step S023 further includes using the furnace wall casting material to completely cast the iron taphole during furnace wall casting.

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