A method and device for repairing water leakage of serpentine pipe of blast furnace cooling wall

Abstract

The present invention provides a method and device for repairing water leakage of serpentine pipes of blast furnace cooling staves, so as to solve the technical problems that serpentine pipes of blast furnace cooling staves are difficult to repair and the cooling effect is poor after repair. The method comprises the following steps: step S1, furnace shell opening: according to the positioning of the serpentine pipe inside the cooling stave, the positions of multiple straight pipe sections and elbow sections of the serpentine pipe are positioned, and the connection positions of the straight pipe sections and the elbows are marked, and a first hole with a diameter larger than the outer diameter of the serpentine pipe is drilled on the furnace shell surface corresponding to the marked position, and the refractory between the furnace shell and the cooling stave is cleaned; step S2, cooling stave opening: at the hole opening position in step S1, the cooling stave is opened. A second hole is drilled, the second hole is connected to the inside of the serpentine tube, and the diameter of the second hole is equal to the inner diameter of the serpentine tube; step S3, welding the connecting pipe: welding the connecting pipe at the position of the first hole, one end of the connecting pipe is fixedly connected to the furnace shell, and the other end extends to the outside of the furnace shell; step S4, pipe threading: respectively inserting multiple groups of hoses into multiple groups of straight pipe sections in the cooling wall, and the two ends of the hoses are respectively connected to the two groups of connecting pipes on the same group of straight pipe sections, and the hoses are fixed to the connecting pipes; step S5, water supply: respectively introduce cooling water into the interior of the multiple groups of hoses, and each group of hoses is a separate cooling water circuit.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace cooling devices, and in particular to a method and a device for repairing water leakage of a serpentine pipe of a blast furnace cooling stave. Background Art

[0002] Blast furnace cooling stave is an important component of iron-making blast furnace in metallurgical industry. It is mainly used to protect the shell of blast furnace from erosion by high-temperature slag and hot air flow, and effectively conduct heat out of the furnace to maintain a suitable operating temperature inside the blast furnace. The cooling stave is usually composed of refractory materials and cooling elements, among which the cooling elements are generally serpentine cooling water pipes, which are embedded or attached behind the refractory materials.

[0003] The following hidden dangers exist in the leakage of blast furnace cooling wall: ① Water leakage from the cooling wall causes the furnace temperature to drop, affecting production; ② The cooling wall leaks a large amount of water into the furnace, and high-temperature gasification produces a large amount of hydrogen, causing an explosion; ③ If the cooling wall is cut off from water, it may easily lead to burning of the cooling wall and burning through of the furnace shell if remedial measures are not taken in time; ④ Damage to the blast furnace lining can easily cause furnace conditions to become unfavorable and affect the life of the blast furnace; ⑤ It causes the fuel consumption of blast furnace to increase and the smelting cost to increase; ⑥ This causes the moisture content in the coal gas to increase, making it difficult to unload the blast furnace bags and causing bag ash to clog the pipeline.

[0004] The traditional treatment method for the leakage of the serpentine pipe in the cooling wall: after the cooling wall is found to be leaking, the amount of cooling water at the leaking point is reduced. However, after the amount of water is reduced, the cooling capacity of the cooling wall decreases, the temperature difference increases, and local boiling occurs inside the cooling wall water pipe, which can easily lead to further damage to the cooling wall. Only when the blast furnace is stopped for maintenance, the leaking part is boiled, and the overall structure of the cooling wall is destroyed. Cooling columns are installed on the cooling wall at the leaking part. Similarly, the repair method of installing cooling column also has problems: A. Open 6-8 holes with a diameter of 120mm on the furnace shell. If the holes are too large, the strength and rigidity of the furnace shell will be affected, resulting in uneven stress distribution of the furnace shell, especially forming stress concentration areas around the holes. This stress concentration will reduce the overall strength and rigidity of the furnace shell, and increase the risk of deformation or even rupture of the furnace shell under high temperature and high pressure environment; B. A large number of openings will damage the structural integrity of the furnace shell, reduce the effective bearing area, and thus reduce the furnace shell's ability to resist internal pressure, which not only affects the stability of the blast furnace, but may also cause cracks or other structural damage to the furnace shell during use; C. Installing cooling columns on damaged cooling staves requires burning corresponding holes in the complete wall. In the process of burning oxygen, poor control of angle and oxygen volume has led to the expansion of furnace shell burnout. Excessive melting loss of the cooling stave wall can easily lead to reddening of the furnace skin and burn-through. D. Due to the damage of the cooling wall and the subsequent installation of cooling columns, uneven temperature distribution may occur, which will affect the overall stability of the blast furnace. The uneven temperature distribution may cause uneven heating of the furnace shell, thus affecting the operating efficiency and safety of the blast furnace; E. The process of burning oxygen in the furnace shell and cooling wall generates high temperature, thick smoke and dust, which causes environmental pollution.

[0005] In addition, in the prior art, such as the blast furnace cooling wall water cooling pipe repair method disclosed in publication number CN1204271C, a pressurized method is used to lay a corrugated pipe to replace the damaged water cooling pipe. However, the operation is complicated. Since the water pressure cannot be accurately controlled, it is easy to cause the corrugated pipe to burst and crack, thereby causing water leakage. Moreover, since there are many bends inside the cooling wall, the size of the corrugated pipe needs to be reduced in order to pass through more than two elbows. This method will result in a decrease in the cooling strength of the repaired cooling wall. Summary of the invention

[0006] The present invention provides a method and device for repairing water leakage of a blast furnace cooling stave serpentine tube, so as to solve the technical problems that the blast furnace cooling stave serpentine tube is difficult to repair and the cooling effect is poor after repair. In order to achieve the above purpose, the technical scheme adopted is as follows: A method for repairing a blast furnace cooling stave serpentine tube, characterized in that it comprises the following steps: Step S1, furnace shell opening: according to the positioning of the serpentine tube inside the cooling wall, locate the positions of the multiple straight tube sections and the elbow sections of the serpentine tube, and mark the connection positions of the straight tube sections and the elbows, drill a first hole with a diameter larger than the outer diameter of the serpentine tube on the furnace shell surface corresponding to the marked position, and clean the refractory between the furnace shell and the cooling wall; Step S2, drilling a hole in the cooling wall: drilling a second hole in the cooling wall at the hole drilling position in step S1, wherein the second hole is connected to the interior of the serpentine tube, and the diameter of the second hole is equal to the inner diameter of the serpentine tube; Step S3, welding the connecting pipe: welding the connecting pipe at the first hole position, wherein one end of the connecting pipe is fixedly connected to the furnace shell, and the other end extends to the outside of the furnace shell; Step S4, pipe threading: inserting the multiple groups of hoses into the multiple groups of straight pipe sections in the cooling wall respectively, connecting the two ends of the hoses to the two groups of connecting pipes on the same group of straight pipe sections respectively, and fixing the hoses to the connecting pipes; Step S5, water supply: cooling water is introduced into the multiple groups of hoses separately, and each group of hoses is a separate cooling water circuit.

[0007] Furthermore, in step S3, a corrugated compensator is welded between the outer wall of the connecting pipe and the furnace shell.

[0008] Furthermore, in step S4, high thermal conductivity silicon carbide slurry is filled between the hose and the serpentine tube.

[0009] Furthermore, in step S5, the original water inlet and the original water return port on the serpentine pipe and the multiple groups of connecting pipes are redistributed, wherein the water inlet is set at the lower part of the straight pipe section, and the water return port is set at the upper part of the straight pipe section.

[0010] Furthermore, the hose in step S4 is a corrugated tube.

[0011] A device for repairing water leakage of a blast furnace cooling stave serpentine pipe comprises a furnace shell, a cooling stave and a serpentine pipe located in the cooling stave, wherein two ends of the serpentine pipe are respectively connected to a first water inlet pipe and a first water return pipe extending out of the furnace shell, and is characterized in that it also comprises: The hoses are provided in multiple groups and are respectively arranged in the straight pipe sections of the serpentine pipes, and both ends of the hoses are respectively fixedly connected to the furnace shell; The connecting pipe is provided with an even array, which is arranged at the connection between the straight pipe section and the elbow section of the serpentine pipe and connected to the hose. The connecting pipe, the first water inlet pipe and the first water return pipe located on the same straight pipe section are the water inlet and water return of the cooling water circuit respectively.

[0012] Furthermore, the connecting pipe, the first water inlet pipe and the first water return pipe on the same straight pipe section, the one located below the straight pipe section is the water inlet of the cooling water circuit, and the one located above the straight pipe section is the water return port.

[0013] Furthermore, a corrugated compensator is connected between the cooling connecting pipe and the outer wall of the furnace shell.

[0014] Furthermore, a grouting cavity is formed between the sleeve and baffle of the corrugated compensator and the furnace shell, the grouting cavity is connected to the gap between the hose and the serpentine tube, and a grouting hole connected to the grouting cavity is provided on the sleeve.

[0015] Furthermore, the furnace shell and the cooling wall are respectively provided with a first hole and a second hole distributed corresponding to the position of the connecting pipe, the diameter of the first hole is larger than the outer diameter of the serpentine tube, and the second hole penetrates into the interior of the serpentine tube and has a diameter equal to the inner diameter of the serpentine tube.

[0016] The invention is beneficial in that: 1. The serpentine pipe is divided into a straight pipe section and an elbow section, and the cooling water circuit is arranged on the straight pipe section to avoid the need to use a corrugated pipe with a smaller diameter to pass through the elbow section. The outer diameter of the corrugated pipe in the straight pipe section is the same as the inner diameter of the serpentine pipe, which effectively increases the cross-sectional area of ​​the cooling water circuit. The inlet pipe and return pipe of each cooling water circuit are arranged at the connection between the straight pipe section and the elbow section, which increases the length of the cooling circuit. The above-mentioned setting of the cooling water circuit effectively increases the cooling water flow in the cooling water circuit, thereby improving the cooling effect of the cooling wall; 2. Using multiple sets of separate cooling water pipelines to cool the serpentine tube can effectively improve the cooling uniformity compared to the prior art method of using a single continuous and curved bellows repair method, thereby further improving the cooling effect; 3. The upper and lower ends of the same straight pipe section are the outlet pipe and the return pipe respectively. The low-inlet and high-outlet layout can ensure that the bubbles generated by the cooling water in the corrugated pipe due to heat can be discharged in time to improve the cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the present invention Figure 2 for Figure 1 AA section view in Figure 3 for Figure 2 A partial enlarged schematic diagram of point B in the middle in: 1-furnace shell, 101-first hole; 2-cooling wall, 201-second hole; 3-serpentine pipe, 301-straight pipe section, 302-elbow section; 4-first water inlet pipe, 5-first water return pipe, 6-insulation layer, 7-connecting pipe, 8-corrugated pipe; 9-corrugated compensator, 901-corrugated section, 902-outer sleeve, 903-baffle, 904-grouting hole; 10-High thermal conductivity silicon carbide slurry layer. DETAILED DESCRIPTION

[0018] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0019] In the description of the invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the viewing direction or positional relationships and are only for the convenience of describing the invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0020] A method for repairing water leakage of a blast furnace cooling wall serpentine tube comprises the following steps: Step S1, drilling a hole in the furnace shell 1: according to the positioning of the serpentine tube 3 inside the cooling stave 2, the positions of the multiple straight tube sections 301 and the elbow section 302 of the serpentine tube 3 are positioned, and the connection position of the straight tube section 301 and the elbow section 302 is marked, and a first hole 101 with a diameter larger than the outer diameter of the serpentine tube 3 is drilled on the surface of the furnace shell 1 corresponding to the marked position, and the refractory between the furnace shell 1 and the cooling stave 2 is cleaned; According to the design drawing of the cooling wall 2, the continuously distributed serpentine pipe 3 is divided into a plurality of straight pipe sections 301 and elbow sections 302. In this embodiment, the straight pipe section 301 is provided with four sections, and the elbow section 302 is provided with three sections. The original first water inlet pipe 4 and the first water return pipe 5 at both ends of the serpentine pipe 3 are both located at the upper end position. The refractory material between the furnace shell 1 and the cooling wall 2 is a heat insulation layer 6, and the diameter of the first hole 101 opened on the furnace shell 1 is larger than the outer diameter of the straight pipe section 301. After the hole opening is completed, the furnace shell 1 and the cooling wall 2 are connected. The insulation layer 6 between the furnace shell 1 and the cooling wall 2 is cleaned. The first hole 101 in this embodiment is 15 mm larger than the outer diameter of the serpentine tube 3. Its purpose is to facilitate the cleaning of the insulation layer 6 between the furnace shell 1 and the cooling wall 2, and to facilitate positioning when opening a hole in the cooling wall 2, and to facilitate pulling the corrugated tube 8 into the interior of the serpentine tube 3. Compared with the traditional method of opening a 150-200 mm hole in the furnace shell 1, the strength of the furnace shell 1 is ensured, and cracking caused by stress changes at the position of the first hole 101 in the later stage is avoided.

[0021] Step S2, drilling a hole in the cooling wall: drilling a second hole 201 in the cooling wall 2 at the hole drilling position in step S1, wherein the second hole 201 is connected to the inside of the serpentine tube 3, and the diameter of the second hole 201 is equal to the inner diameter of the serpentine tube 3; The cooling wall 2 is drilled with a magnetic drill. The diameter of the second hole 201 is equal to the inner diameter of the straight pipe section 301. After the drilling is completed, the interior is cleaned.

[0022] Step S3, welding the connecting pipe 7: welding the connecting pipe 7 at the position of the first hole 101, wherein one end of the connecting pipe 7 is fixedly connected to the furnace shell 1, and the other end extends out of the furnace shell 1; The connecting pipe 7 having a diameter consistent with that of the straight pipe section 301 is welded to the first hole 101 on the outside of the furnace shell 1 , and the connecting pipe 7 is welded and fixed to the outer wall of the furnace shell 1 through a corrugated compensator 9 to absorb the displacement of the cooling wall 2 .

[0023] Step S4, pipe threading: inserting multiple groups of bellows 8 into multiple groups of straight pipe sections 301 in the cooling wall 2, respectively, connecting two ends of the bellows 8 to two groups of connecting pipes 7 on the same group of straight pipe sections 301, or connecting two ends of the bellows 8 to the connecting pipes and the original first water inlet pipe 4 or the first water return pipe 5, fixing the bellows 8 to the furnace shell 1, and filling high thermal conductivity silicon carbide slurry between the inner wall of the serpentine pipe 3 and the outer wall of the bellows 8; In the case where two groups of connecting pipes 7 are opened on the straight pipe section 301, the bellows 8 is first welded and fixed to one group of connecting pipes 7, then introduced into the straight pipe section 301 by wire rope traction, and finally welded and fixed to the other group of connecting pipes; For the straight pipe section 301 provided with the first water inlet pipe 4 and the first water return pipe 5, one end of the corrugated pipe 8 is welded and connected to the original first water inlet pipe 4 or the first water return pipe 5, and then the other end is pulled into the straight pipe section 301 by a steel wire rope and welded and fixed to the connecting pipe 7.

[0024] Step S5, water supply: cooling water is introduced into the multiple groups of bellows 8 separately, and each group of bellows 8 is a separate cooling water circuit; Each group of bellows 8 forms a separate low-inlet and high-outlet water supply circuit, that is, the first water inlet pipe 4, the first water return pipe 5, and six groups of connecting pipes 7 located on the same group of straight pipe sections 301 are connected to the external cooling device in groups of two, the water inlet pipe at the lower end is connected to the water outlet of the cooling device, and the seat return pipe at the upper end is connected to the water return port of the cooling device, thereby forming four separate cooling circuits.

[0025] The outer diameter of the bellows 8 is the same as the inner diameter of the straight pipe section 301, and the water inlet pipe and the water return pipe are arranged at the connection between the straight pipe section 301 and the elbow section 302, so as to avoid the need to use a smaller diameter bellows through the elbow section 302, which would lead to a reduction in the cooling water flow rate. The above-mentioned arrangement ensures the cooling water flow rate in the cooling circuit as much as possible, thereby improving the cooling effect; moreover, the use of multiple groups of cooling circuits and the arrangement of the water inlet pipe and the water return pipe can improve the cooling effect and ensure the uniformity of cooling; in addition, the individual cooling circuit adopts a low-inlet and high-outlet water supply method, which can ensure that the bubbles generated by the heating of the cooling water inside the bellows 8 can be discharged in time, further improving the cooling effect.

[0026] A blast furnace cooling wall serpentine tube repair device, such as Figure 1-Figure 3 As shown, it includes a furnace shell 1, a cooling wall 2, a serpentine pipe 3, a first water inlet pipe 4, a first water return pipe 5 and multiple groups of connecting pipes 7 and a bellows 8. The first water inlet pipe 4 and the first water return pipe 5 are respectively located at the two ends of the serpentine pipe 3, serving as the water inlet pipe and the water return pipe of the original cooling water.

[0027] Specifically, the serpentine tube 3 is composed of four groups of straight pipe sections 301 and three groups of elbow sections 302. A first hole 101 and a second hole 201 are respectively opened on the furnace shell 1 and the cooling wall 2 at the connection between the straight pipe section 301 and the elbow section 302, and a group of connecting pipes 7 is arranged at the lower end of the straight pipe section 301 where the first water inlet pipe 4 or the first return water pipe 5 is arranged, and a group of connecting pipes 7 are respectively arranged at the upper and lower ends of the other two groups of straight pipe sections 301. A group of corrugated pipes 8 located inside the straight pipe section 301 is connected between the first water inlet pipe 4 and the connecting pipe 7, between the first return water pipe 5 and the connecting pipe 7, and between the two groups of connecting pipes 7 located on the same group of straight pipe sections 301.

[0028] In this embodiment, the outer diameter of the serpentine tube 3 is 40 mm, the diameter of the first hole 101 is 55 mm, the diameter of the second hole is 40 mm, the outer diameter of the bellows 8 is the same as the inner diameter of the serpentine tube 3, the bellows 8 is welded to the connecting pipe 7 or the original first water inlet pipe 4 or the first return water pipe 5, and the connecting pipe 7 and the furnace shell 1 are fixedly connected by a bellows compensator 9, and the gap between the outer wall of the bellows 8 and the inner wall of the serpentine tube 3 is filled with a high thermal conductivity silicon carbide mud layer 10.

[0029] In this embodiment, the outer sleeve of the bellows compensator 9 is welded to the outer wall of the furnace shell 1 at one end close to the furnace shell 1, and a cavity is formed between the outer sleeve, the baffle and the first hole 101 on the furnace shell 1. The cavity is connected to the gap between the bellows 8 and the serpentine tube 3, and a grouting hole is opened on the outer sleeve. High thermal conductivity silicon carbide slurry can be filled into the gap between the bellows 8 and the serpentine tube 3 through the grouting hole to improve the thermal conductivity between the bellows 8 and the serpentine tube 3.

[0030] In addition, the bellows 8 in each group of straight pipe sections 301 serves as a separate cooling water circuit, that is, the first water inlet pipe 4, the connecting pipe 7 or the first water return pipe 5 located above the straight pipe section 301 serves as a new water inlet pipe and is connected to the water outlet of the cooling device, and the connecting pipe 7 located at the lower end of the same group of straight pipe sections 301 serves as a new water return pipe and is connected to the water return port of the cooling device, so as to realize four groups of separately distributed low-inlet and high-outlet cooling water circuits.

[0031] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A method for repairing a blast furnace cooling wall serpentine tube, characterized in that: The following steps are involved: Step S1, furnace shell opening: according to the positioning of the serpentine tube inside the cooling wall, locate the positions of the multiple straight tube sections and the elbow sections of the serpentine tube, and mark the connection positions of the straight tube sections and the elbows, drill a first hole with a diameter larger than the outer diameter of the serpentine tube on the furnace shell surface corresponding to the marked position, and clean the refractory between the furnace shell and the cooling wall; Step S2, drilling a hole in the cooling wall: drilling a second hole in the cooling wall at the hole drilling position in step S1, wherein the second hole is connected to the interior of the serpentine tube, and the diameter of the second hole is equal to the inner diameter of the serpentine tube; Step S3, welding the connecting pipe: welding the connecting pipe at the first hole position, wherein one end of the connecting pipe is fixedly connected to the furnace shell, and the other end extends to the outside of the furnace shell; Step S4, pipe threading: inserting the multiple groups of hoses into the multiple groups of straight pipe sections in the cooling wall respectively, connecting the two ends of the hoses to the two groups of connecting pipes on the same group of straight pipe sections respectively, and fixing the hoses to the connecting pipes; Step S5, water supply: cooling water is introduced into the multiple groups of hoses separately, and each group of hoses is a separate cooling water circuit.

2. The cooling wall serpentine pipe repair method according to claim 1, characterized in that: In the step S3, a corrugated compensator is welded between the outer wall of the connecting pipe and the furnace shell.

3. The cooling wall serpentine pipe repair method according to claim 1, characterized in that: In the step S4, high thermal conductivity silicon carbide slurry is filled between the hose and the serpentine tube.

4. The cooling wall serpentine pipe repair method according to claim 1, characterized in that: In step S5, the original water inlet and the original water return port on the serpentine pipe and the multiple groups of connecting pipes are redistributed, wherein the water inlet is set at the lower part of the straight pipe section, and the water return port is set at the upper part of the straight pipe section.

5. The cooling wall serpentine pipe repair method according to claim 1, characterized in that: The hose in step S4 is a corrugated tube.

6. A blast furnace cooling stave serpentine pipe leakage repair device, comprising a furnace shell, a cooling stave and a serpentine pipe located in the cooling stave, wherein the two ends of the serpentine pipe are respectively connected to a first water inlet pipe and a first water return pipe extending out of the furnace shell, characterized in that: Also includes: The hoses are provided in multiple groups and are respectively arranged in the straight pipe sections of the serpentine pipes, and both ends of the hoses are respectively fixedly connected to the furnace shell; The connecting pipe is provided with an even array, which is arranged at the connection between the straight pipe section and the elbow section of the serpentine pipe and connected to the hose. The connecting pipe, the first water inlet pipe and the first water return pipe located on the same straight pipe section are the water inlet and water return of the cooling water circuit respectively.

7. The blast furnace cooling stave serpentine pipe water leakage repair device according to claim 1 is characterized in that: The connecting pipe, the first water inlet pipe and the first water return pipe on the same straight pipe section, the one located below the straight pipe section is the water inlet of the cooling water circuit, and the one located above the straight pipe section is the water return port.

8. The blast furnace cooling stave serpentine pipe water leakage repair device according to claim 1, characterized in that: A corrugated compensator is connected between the cooling connecting pipe and the outer wall of the furnace shell.

9. The blast furnace cooling stave serpentine pipe water leakage repairing device according to claim 8, characterized in that: A grouting cavity is formed between the sleeve and baffle of the corrugated compensator and the furnace shell. The grouting cavity is connected to the gap between the hose and the serpentine pipe. A grouting hole connected to the grouting cavity is provided on the sleeve.

10. The blast furnace cooling stave serpentine pipe water leakage repairing device according to claim 1, characterized in that: The furnace shell and the cooling wall are respectively provided with a first hole and a second hole distributed corresponding to the position of the connecting pipe. The diameter of the first hole is larger than the outer diameter of the serpentine tube, and the second hole penetrates into the interior of the serpentine tube and has a diameter equal to the inner diameter of the serpentine tube.

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