Water tube reinforced scouring resistant blast furnace copper stave

Abstract

The utility model relates to a kind of water pipe reinforced scouring type blast furnace copper cooling wall, belong to blast furnace ironmaking field.Cooling wall body upper and lower ends are provided with inlet and outlet water pipe, inlet and outlet water pipe two ends are equipped with external thread, respectively connect the internal thread and external water supply and drain pipe of cooling wall body;Cooling wall body is also provided with boss, inlet and outlet water pipe are inserted boss by its protection tube set, adopt thread connection and carry out ring welding.Cooling wall body hot face is provided with top surface upwardly inclined dovetail groove, to enhance the ability of charge retention, promote the formation of stable slag layer.Protection tube includes steel sleeve, steel short pipe arranged in sequence, steel sleeve, steel short pipe are connected by first steel ring sealing welding, steel sleeve and inlet and outlet water pipe are synchronous through furnace shell and extend out furnace shell outer surface.The utility model solves the technical problems, such as the root of inlet and outlet water pipe is easy to tear, furnace shell shearing force damage inlet and outlet water pipe, charge retention is poor, and unstable slag layer, so that the overall durability of copper cooling wall is improved.

Description

Technical Field

[0001] This utility model belongs to the field of blast furnace ironmaking and relates to a water pipe reinforced erosion-resistant copper cooling wall for blast furnaces. Background Technology

[0002] As a core piece of equipment in modern steelmaking processes, the blast furnace's belly, waist, and lower section endure high heat loads exceeding 1400℃ for extended periods, while simultaneously facing multiple physical and chemical erosions from the gas flow, furnace charge, molten slag, and molten iron. This complex operating condition places stringent demands on the reliability of the cooling system. Traditional cast iron cooling walls, due to inherent material limitations, generally have low thermal conductivity, maintaining only around 40 W / (m·K), leading to heat accumulation within the wall and the formation of a significant thermal gradient. When the furnace temperature fluctuates drastically, uneven thermal expansion occurs within the cooling wall, resulting in thermal stress concentration. Over long-term operation, this thermal stress cycle causes microcracks to appear on the cooling wall surface, gradually expanding into through-cracks, ultimately leading to the rupture of cooling water channels or even the complete burnout and failure of the cooling wall.

[0003] Compared to cast iron, copper cooling walls have become a breakthrough in blast furnace lifespan extension technology due to their superior thermophysical properties. Copper has a thermal conductivity exceeding 380 W / (m·K), enabling rapid heat transfer to the cooling water system and significantly reducing the temperature gradient within the wall. Simultaneously, copper exhibits excellent resistance to thermal fatigue, with a thermal cycle life 5-8 times that of cast iron. These characteristics allow copper cooling walls to maintain structural integrity and extend their service life when dealing with temperature fluctuations caused by blast furnace charge movement and tapping operations.

[0004] However, pure copper exhibits significant mechanical property defects under high-temperature conditions. When the temperature exceeds 400℃, the yield strength of copper decreases sharply, making the cooling wall prone to plastic deformation under the combined effects of thermal stress and mechanical load. This is particularly pronounced in the root region of the water pipes, where the rapid removal of heat by the cooling water creates localized cold zones, resulting in a significant difference in thermal expansion between these areas and the surrounding high-temperature regions. This stress concentration triggers the initiation of microcracks, which, under thermal cycling, propagate into penetrating cracks, causing leaks at the connection between the water pipe and the wall.

[0005] Furthermore, the traditional working surface structure design of cooling walls has inherent defects. The retention capacity of the furnace charge within the dovetail groove is insufficient; during blast furnace operation, the charge easily slips off the dovetail groove under gravity, making it difficult for the slag layer to adhere stably. Frequent slag layer detachment causes drastic fluctuations in the heat load on the cooling wall surface. When the slag layer is present, the heat flux density can decrease by 30%-50%; however, after the slag layer detaches, the heat flux density increases sharply, causing the cooling wall to endure alternating thermal shock. This periodic change in heat load accelerates the aging process of the cooling wall material, leading to thermal fatigue damage and further shortening its service life.

[0006] The combined effect of these technological bottlenecks has resulted in the lifespan of blast furnace copper cooling wall equipment generally falling short of expectations, severely restricting the improvement of blast furnace production efficiency. Therefore, developing a new type of copper cooling wall with high thermal conductivity, excellent thermal shock resistance, and resistance to furnace charge erosion has become a key technological direction for extending blast furnace lifespan and reducing maintenance costs. Utility Model Content

[0007] In view of this, the purpose of this utility model is to provide a water pipe reinforced erosion-resistant blast furnace copper cooling wall, which solves the problems of easy tearing at the root of the water pipe, damage to the water pipe by furnace shell shear force, and easy wear on the hot surface of the current blast furnace copper cooling wall, thereby improving the reliability and durability of the copper cooling wall.

[0008] To achieve the above objectives, this utility model provides the following technical solution: A water-pipe-reinforced erosion-resistant blast furnace copper cooling wall includes a cooling wall body and inlet and outlet water pipes disposed at the upper and lower ends of the cooling wall body. The end of the inlet and outlet water pipes near the cooling wall body is provided with an external thread, and the cooling wall body is correspondingly machined with an internal thread at the position for connecting the inlet and outlet water pipes. The external thread and the internal thread form a threaded fit. The cooling wall body is also provided with a boss at the position for connecting the inlet and outlet water pipes. A protective tube is sleeved on the outside of the end of the inlet and outlet water pipes near the cooling wall body. The inlet and outlet water pipes and the protective tube are simultaneously inserted into the boss, and the inner side of the protective tube is connected to the boss by a thread and annular weld.

[0009] Optionally, the cooling wall body has a plurality of dovetail grooves on the hot side away from the inlet and outlet water pipes. The top surface of each dovetail groove is inclined upward relative to the normal of the wall surface of the cooling wall body, with an inclination angle of 5° to 45°.

[0010] Optionally, the depth of the dovetail groove is 30mm to 80mm.

[0011] Optionally, the surface of the dovetail groove is provided with a shot peening strengthening layer, and the surface roughness Ra of the shot peening strengthening layer is 10μm~15μm, which is beneficial to the adhesion of slag skin.

[0012] Optionally, the protective pipe includes a steel sleeve fitted onto the inlet and outlet water pipes, and a short steel pipe connected to the inner side of the boss. The steel sleeve and the short steel pipe are sealed together by a first steel ring and a connecting weld.

[0013] Optionally, the steel sleeve passes through the blast furnace shell simultaneously with the inlet and outlet water pipes, and extends 5mm to 100mm beyond the outer surface of the furnace shell. The thickness of the steel sleeve is 4mm to 10mm.

[0014] Optionally, the height of the boss is 10mm to 40mm, and the outer diameter of the boss is 10mm to 30mm larger than the outer diameter of the steel short pipe.

[0015] Optionally, the boss is an annular boss or a rectangular boss.

[0016] Optionally, a second steel ring is welded to one end of the inlet / outlet water pipe away from the cooling wall body, and an external thread is provided for welding an external corrugated expansion joint.

[0017] The beneficial effects of this utility model are as follows: This invention solves the technical problems of easy tearing at the root of the inlet and outlet water pipes in blast furnace copper cooling walls, damage to the inlet and outlet water pipes by furnace shell shear force, poor retention capacity of furnace charge on the hot surface, and unstable slag layer. By setting a boss structure at the root of the inlet and outlet water pipes, the local thickness is increased, reducing stress concentration. A composite connection method of threaded engagement and welding is adopted between the inlet and outlet water pipes and the cooling wall body. The threads are pre-tightened first, and then welded for sealing and fixing, significantly improving the root bonding strength and thermal fatigue resistance, and significantly enhancing the connection strength and reliability of the inlet and outlet water pipes. A steel sleeve is fitted outside the inlet and outlet water pipes, passing through the furnace shell simultaneously with the water pipes, forming a double-layer protective structure. This effectively resists the shear force generated by the thermal deformation of the furnace shell, preventing the copper pipes from being directly deformed or cracked by stress, and improving overall reliability. The vertical dovetail groove structure on the working surface of the cooling wall is improved by making the upper surface of the dovetail groove inclined upwards relative to the normal of the cooling wall surface. Combined with surface shot peening, this significantly enhances the charge retention capacity and promotes the formation of a stable slag layer. The inclined structure of the dovetail groove, whether implemented in the blast furnace belly, waist, or body, significantly improves charge retention and slag adhesion performance. The retained charge and slag layer effectively protect the copper cooling wall, reducing edge material velocity to a certain extent and resisting subsequent charge and slag erosion. This reduces heat load fluctuations, thereby improving the erosion resistance and service life of the copper cooling wall's hot surface.

[0018] Through the above structural optimization, the reliability of the water pipe roots, resistance to mechanical damage, and slag adhesion of the copper cooling wall are significantly improved, thereby enhancing the overall durability of the copper cooling wall. It is expected to extend the service life of the copper cooling wall to over 15 years, meeting the requirements of the first generation of blast furnace life. It is suitable for high-heat-load operating environments such as the blast furnace belly, waist, and lower part of the furnace body, extending the blast furnace overhaul cycle and offering significant economic benefits.

[0019] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is an overall schematic diagram of the present invention when implemented in the blast furnace body. Figure 2 for Figure 1 Enlarged view of the upper part of the intermediate cooling wall; Figure 3 This is an overall schematic diagram of the present invention when implemented in the belly of a blast furnace; Figure 4 This is an enlarged schematic diagram of the protective pipe at the root of the inlet and outlet water pipes according to this utility model; Figure 5 This is a schematic diagram illustrating how the present invention improves the retention of furnace charge in the furnace body.

[0021] Figure label: 1 Cooling wall body, 2 Inlet and outlet water pipes, 3 Water pipe steel ring - second steel ring, 4 Furnace shell, 5 Steel sleeve, 6 Boss, 7 Dovetail groove, 8 First steel ring, 9 Steel short pipe. Detailed Implementation

[0022] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0023] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model 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 drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] Please see Figures 1-5 This invention relates to a water-pipe-reinforced, erosion-resistant blast furnace copper cooling wall, comprising a cooling wall body 1 and inlet / outlet water pipes 2 disposed at the upper and lower ends of the cooling wall body 1. The end of the inlet / outlet water pipe 2 closest to the cooling wall body 1 has an external thread, and the cooling wall body 1 has a corresponding internal thread machined at the location for connecting the inlet / outlet water pipes 2. The external and internal threads form a threaded fit, and the inlet / outlet water pipes 2 are first connected to the cooling wall body 1 via these threads. The cooling wall body 1 also has a boss 6 for connecting the inlet / outlet water pipes 2. A protective tube is fitted around the end of the inlet / outlet water pipe 2 closest to the cooling wall body 1. The inlet / outlet water pipes 2 and the protective tube are simultaneously inserted into the boss 6, and the inner side of the protective tube is connected to the boss 6 via a threaded connection and a circumferential weld.

[0026] The cooling wall body 1 has several dovetail grooves 7 on the hot side away from the inlet and outlet water pipes 2. The end of the inlet and outlet water pipes 2 away from the cooling wall body 1 is welded with a second steel ring for welding external corrugated expansion joints.

[0027] Example 1 This embodiment provides a specific reinforcement scheme for the root of the copper cooling wall inlet and outlet water pipes 2. In this embodiment, the boss 6 can be an annular boss 6 or a rectangular boss 6, and the height of the boss 6 is 10mm~40mm.

[0028] Preferably, a rectangular boss 6 with a height of 15mm is provided at the water pipe installation position of the copper cooling wall body 1. The side length of the boss 6 is 20mm larger than the outer diameter of the inlet and outlet water pipes 2. Both ends of the inlet and outlet water pipes 2 are machined with M75 external threads. The inner end mates with the corresponding internal threads machined inside the cooling wall, and the outer end mates with the external water supply and drainage connecting pipes. During manufacturing and assembly, the inner end of the inlet and outlet water pipes 2 is first screwed into the cooling wall to the predetermined position. Then, tungsten inert gas welding (TIG) is used to perform circumferential welding along the joint to the boss 6. After welding, local heat treatment is performed to eliminate residual stress.

[0029] In this embodiment, the tensile strength of the two water inlet and outlet pipes is significantly improved compared to the weak structure of traditional direct welding.

[0030] Example 2 Based on Embodiment 1 above, this embodiment further specifies that the protective pipe includes a steel sleeve 5 fitted onto the inlet / outlet water pipe 2, and a short steel pipe 9 connected to the inner side of the boss 6. The steel sleeve 5 and the short steel pipe 9 are sealed and welded together by a first steel ring 8. The steel sleeve 5 and the inlet / outlet water pipe 2 pass through the blast furnace shell 4 simultaneously and extend 5mm to 100mm beyond the outer surface of the shell 4. The thickness of the steel sleeve 5 is 4mm to 10mm. The gap between the steel sleeve 5 and the inlet / outlet water pipe 2 is approximately 1mm to 5mm. In this embodiment, the welding seal between the components is achieved using processes such as tungsten inert gas welding or electron beam welding.

[0031] Furthermore, the outer diameter of the boss 6 is 10mm to 30mm larger than the outer diameter of the steel short pipe 9.

[0032] Specific examples Figure 4 As shown, in this embodiment, the steel sleeve 5 is made of 304 stainless steel, with an inner diameter 2mm larger than the outer diameter of the inlet / outlet water pipe 2 and a wall thickness of 6mm; the steel short pipe 9 inside the boss 6 has an outer diameter of 140mm and a wall thickness of 8mm; the steel sleeve 5 and the steel short pipe 9 are welded together as a single protective pipe via the first steel ring 8. During assembly, the single protective pipe is inserted into the inlet / outlet water pipe 2, and one end of the steel short pipe 9 is circumferentially welded to the boss 6 using tungsten inert gas welding (TIG) along the joint. During on-site hoisting, the steel sleeve 5 and the inlet / outlet water pipe 2 are simultaneously passed through the opening in the blast furnace shell 4.

[0033] This embodiment can significantly enhance the ability of the inlet and outlet water pipes 2 to resist thermal deformation and effectively resist the mechanical damage that the shear force generated by the furnace shell 4 may cause to the inlet and outlet water pipes 2.

[0034] Example 3 This embodiment improves the dovetail groove 7 on the working surface of the cooling wall. The top surface of each dovetail groove 7 is inclined upward relative to the normal of the cooling wall body 1, with an inclination angle of 5°~45°. The groove depth of the dovetail groove 7 is 30mm~80mm; the surface of the dovetail groove 7 is provided with a shot peening strengthening layer, and the surface roughness Ra of the shot peening strengthening layer is 10μm~15μm, which is beneficial to the adhesion of slag skin.

[0035] The top and bottom surfaces of the dovetail groove 7 can be parallel or not. When they are not parallel, the inner and outer widths of the dovetail groove 7 can be inconsistent, and the inclination angles on both sides can be different.

[0036] Preferred, such as Figure 2 As shown, the traditional 90° vertical groove is replaced with a 15° upward-sloping dovetail groove 7, with a groove depth of 40 mm and a groove spacing of 86 mm. The inner surface of the groove is shot-peened to increase the roughness (Ra=12.5μm).

[0037] like Figure 5As shown, when the cooling wall of this embodiment is applied to the furnace body, it can significantly improve the furnace charge retention capacity; when applied to the furnace waist and furnace belly of the furnace charge softening zone, compared with the traditional dovetail groove 7 structure, it is also significantly beneficial to stabilize the slag skin, reduce the temperature fluctuation of the hot surface, and extend the expected service life of the copper cooling wall against erosion and wear by more than 2 years.

[0038] Example 4 This embodiment is a comprehensive application example of the above embodiments. In the blast furnace overhaul project, the technical solution of this utility model is fully applied to high heat load areas such as the furnace belly, furnace waist, and lower part of the furnace body. The specific implementation method is as follows: The root reinforcement scheme of the inlet and outlet water pipes 2 in Example 1 is adopted. A 15mm high annular boss 6 is set on the copper cooling wall body 1 to increase the local thickness and reduce stress concentration. The inlet and outlet water pipes 2 and the cooling wall body adopt a composite connection method of M75 thread fit + tungsten inert gas welding. The thread is pre-tightened first, and then high-precision welding is used to seal and fix it, which greatly improves the root bonding strength and thermal fatigue resistance. The protective pipe of Example 2 is added and passes through the furnace shell 4 at the same time as the inlet and outlet water pipes 2 to form a double-layer protective structure. The steel sleeve 5 is made of 6mm thick 304 stainless steel, which can effectively resist the shear force generated by the thermal deformation of the furnace shell 4, avoid the inlet and outlet water pipes 2 from being directly deformed or cracked by force, and improve the overall reliability. The working surface of the copper cooling wall hot surface adopts the 15° upward inclined dovetail groove 7 design of Example 3. The surface of the dovetail groove 7 is shot peened and the roughness is controlled at Ra of about 12.5μm. The upward-sloping dovetail groove 7 can enhance the furnace charge retention capacity and promote the formation of a stable slag layer. Whether implemented in the blast furnace belly, waist, or body, the upward-sloping dovetail groove 7 can significantly improve the furnace charge retention and slag adhesion performance. The retained furnace charge and slag skin layer can effectively protect the copper cooling wall, reduce the edge material velocity to a certain extent, resist the scouring of subsequent furnace charge and molten slag, thereby reducing heat load fluctuations and improving the erosion resistance and service life of the copper cooling wall hot surface.

[0039] The comprehensive solution in this embodiment achieves a comprehensive improvement in the durability of the copper cooling wall equipment through multiple optimizations, including the reinforcement structure at the root of the water pipe, the external protection structure of the water pipe, and the optimized design of the dovetail groove 7.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A water-pipe-reinforced erosion-resistant blast furnace copper cooling wall, comprising a cooling wall body (1) and inlet / outlet water pipes (2) disposed at the upper and lower ends of the cooling wall body (1), characterized in that: The inlet and outlet water pipe (2) is provided with an external thread at one end near the cooling wall body (1), and the cooling wall body (1) is provided with an internal thread at the position for connecting the inlet and outlet water pipe (2), and the external thread and the internal thread form a threaded fit; the cooling wall body (1) is also provided with a boss (6) at the position for connecting the inlet and outlet water pipe (2), and a protective tube is provided on the outside of the end of the inlet and outlet water pipe (2) near the cooling wall body (1), and the inlet and outlet water pipe (2) and the protective tube are inserted into the boss (6) at the same time, and the inner side of the protective tube is connected to the boss (6) by a thread and annular weld.

2. The water pipe reinforced erosion-resistant blast furnace copper cooling wall according to claim 1, characterized in that: The cooling wall body (1) has several dovetail grooves (7) on the hot side away from the inlet and outlet water pipes (2). The top surface of each dovetail groove (7) is inclined upward relative to the wall normal of the cooling wall body (1) at an angle of 5° to 45°.

3. The water pipe reinforced erosion-resistant blast furnace copper cooling wall according to claim 2, characterized in that: The depth of the dovetail groove (7) is 30mm~80mm.

4. The water pipe reinforced erosion-resistant blast furnace copper cooling wall according to claim 1, characterized in that: The protective pipe includes a steel sleeve (5) sleeved on the inlet and outlet water pipes (2) and a short steel pipe (9) connected to the inside of the boss (6). The steel sleeve (5) and the short steel pipe (9) are sealed together by a first steel ring (8) and a connecting weld.

5. The water pipe reinforced erosion-resistant blast furnace copper cooling wall according to claim 4, characterized in that: The steel sleeve (5) passes through the blast furnace shell (4) simultaneously with the water inlet and outlet pipes (2), and extends 5mm to 100mm beyond the outer surface of the furnace shell (4). The thickness of the steel sleeve (5) is 4mm to 10mm.

6. The water pipe reinforced erosion-resistant blast furnace copper cooling wall according to claim 4, characterized in that: The height of the boss (6) is 10mm~40mm, and the outer diameter of the boss (6) is 10mm~30mm larger than the outer diameter of the steel short pipe (9).

7. The water pipe reinforced erosion-resistant blast furnace copper cooling wall according to claim 1, characterized in that: The boss (6) is an annular boss (6) or a rectangular boss (6).

8. The water pipe reinforced erosion-resistant blast furnace copper cooling wall according to claim 1, characterized in that: The inlet and outlet water pipes (2) have a second steel ring welded to one end away from the cooling wall body (1), which is used to weld the external corrugated expansion joint.

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