Furnace shell repairing structure of blast furnace top combustion type hot blast stove
By adding an outer layer of furnace shell to the outside of the top-fired hot blast stove and combining it with various other measures, the problem of furnace shell cracking was solved, achieving a safe and rapid repair effect, extending service life and reducing production impact.
Patent Information
- Application Number
- CN202520488650.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-03-18
AI Technical Summary
The furnace shell of the top-fired hot blast stove cracked under high temperature and high pressure, especially in the high-temperature zone of the combustion chamber. Traditional repair methods were ineffective and affected production, and failed to effectively solve the stress corrosion problem.
An outer furnace shell is added to the outside of the original furnace shell and welded to it. It is filled with heat-conducting or corrosion-resistant materials, corrugated compensators and pressure equalization pipes are installed, and temperature monitoring and drainage facilities are combined to eliminate welding residual stress. An external protective layer is installed to solve the cracking problem.
This completely solves the problem of furnace shell cracking, ensures the safe operation of the hot blast stove, reduces production impact, extends furnace shell life, reduces repair costs, and improves safety and economic benefits.
Smart Images
Figure CN223921441U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the black metallurgy field relates to a blast furnace top combustion formula hot blast stove furnace shell repair structure. BACKGROUND
[0002] Since the late 1980s, the application of Shougang top combustion formula hot blast stove in large blast furnace marks the major breakthrough of this technology. Top combustion formula hot blast stove not only has been applied in super large blast furnace, but also realizes high blast temperature of about 1300 DEG C, which significantly improves the production efficiency of blast furnace.
[0003] However, in actual operation, the furnace shell of top combustion formula hot blast stove appears cracking phenomenon under high temperature and high pressure environment, especially in the high temperature zone of combustion chamber. These cracks initially appear at the circumferential and longitudinal welds, although after repair welding treatment, the cracking problem has not been fundamentally solved, but the cracking of base material gradually increases. Due to repeated repair and overall replacement of welds, each repair has caused different degrees of influence on blast furnace production, and the repair effect is not lasting.
[0004] The reasons for the cracking of furnace shell are complex and various, including residual stress, fatigue stress generated in the welding and processing process, and the influence of acidic medium such as chlorine, sulfur ions in blast furnace gas. These factors jointly act under high temperature and high pressure environment, leading to stress corrosion cracking of furnace shell. Especially under high blast temperature condition, the acidic medium such as NOx, SOx, HCl, HF produced by combustion condenses on the inner surface of furnace shell, forming an acidic corrosion environment and accelerating the cracking process of furnace shell.
[0005] Traditional furnace shell repair methods, such as weld repair, overall replacement and annealing treatment, although alleviate the cracking problem to some extent, but do not solve the root cause. These methods not only have limited repair effect, but also have long repair process, great influence on blast furnace production, and negative influence on the service life of furnace lining.
[0006] Therefore, in view of the cracking problem of furnace shell of top combustion formula hot blast stove under the conditions of large-scale and high blast temperature at present, an effective and thorough repair method is urgently needed to ensure production safety, prolong the service life of hot blast stove and promote the further development and application of top combustion formula hot blast stove technology. UTILITY MODEL CONTENTS
[0007] Therefore, the utility model aims at providing a blast furnace top combustion formula hot blast stove furnace shell repair structure, which aims at solving the general furnace shell cracking problem of large-scale and high blast temperature top combustion formula hot blast stove, and giving a repair structure, so that the furnace shell repair is more thorough, the influence on hot blast stove and blast furnace is minimum, and the cracking problem behind can be solved, and the safe operation of hot blast stove is ensured.
[0008] In order to achieve the above object, the utility model provides the following technical scheme:
[0009] A furnace shell repair structure of a blast furnace top combustion type hot blast stove, comprising an outer furnace shell, the outer furnace shell is welded outside the original furnace shell between the top combustion type hot blast stove burner brick support and the combustion chamber brick support cracking, the outer furnace shell is spliced into a whole in the circumferential direction, a gap is arranged between the outer furnace shell and the original furnace shell, and the outer furnace shell is used for bearing the gas pressure of the hot blast stove and realizing gas sealing.
[0010] Optionally, the outer furnace shell is provided with an equalizing pipe for pressure equalization.
[0011] Optionally, the equalizing gas source is taken from the cold air pipeline between the cold air valve and the hot blast stove.
[0012] Optionally, thermometers for temperature monitoring are arranged on the outer furnace shell and the original furnace shell.
[0013] Optionally, the bottom of the outer furnace shell is provided with a drainage facility.
[0014] Optionally, the field weld of the outer furnace shell adopts a welding residual stress elimination measure.
[0015] Optionally, an outer protective layer is arranged outside the outer furnace shell, which is used for improving the temperature of the outer furnace shell and avoiding the influence of extreme weather on the furnace shell.
[0016] Optionally, a device for monitoring the displacement change of the inner and outer furnace shells is arranged on the outer furnace shell.
[0017] The utility model has the advantages of:
[0018] The repair effect is complete: by adding a layer of furnace shell outside the cracked furnace shell and welding it with the original furnace shell, a new overall structure is formed, which effectively solves the problems of repeated cracking of the weld and cracking of the base material in the traditional repair method. This repair method can more completely solve the problem of furnace shell cracking and ensure the safe operation of the hot blast stove.
[0019] The influence on production is small: the repair structure proposed in the scheme can be carried out under the online state of the hot blast stove, without stopping the furnace, which greatly reduces the influence of the repair work on the production of the blast furnace. At the same time, since the repair process is simple and fast, the repair time is short, which further reduces the risk of production interruption.
[0020] The service life of the furnace shell is prolonged: by filling the heat-conducting or corrosion-resistant material between the new and old furnace shells, setting the corrugated compensator, and adopting the equalizing pipe and other measures, the temperature of the furnace shell is effectively reduced, the influence of thermal stress and corrosion medium on the furnace shell is reduced, and the service life of the furnace shell is prolonged.
[0021] Improved economic efficiency: Compared to traditional methods such as weld patching and complete replacement, this solution offers lower repair costs and investment. Furthermore, the thorough repair reduces downtime and maintenance costs caused by furnace shell cracking, thereby improving the overall economic efficiency of the blast furnace.
[0022] Enhancing safety: By installing temperature monitoring devices, drainage facilities, measures to eliminate residual welding stress, and an external protective layer, this solution effectively improves the safety of the furnace shell. These measures can promptly detect and respond to abnormal conditions in the furnace shell, preventing accidents from occurring.
[0023] 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
[0024] 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:
[0025] Figure 1 This is a schematic diagram of the structure of this scheme;
[0026] Figure 2 for Figure 1 A magnified view of area I;
[0027] Figure 3 for Figure 1 Enlarged view of Zone II;
[0028] Figure 4 for Figure 1 A-direction view.
[0029] Attached reference numerals: 1 - Combustion chamber brick support; 2 - Burner brick support; 3 - Outer furnace shell; 4 - Original furnace shell; 5 - Gap between furnace shells; 6 - Heat-conducting or corrosion-resistant material; 7 - Corrugated compensator; 8 - Pressure equalization pipe; 9 - Cold air valve; 10 - Cold air duct; 11 - Thermometer; 12 - Drainage facilities; 13 - Outer protective layer; 14 - Displacement measuring device. Detailed Implementation
[0030] 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 can be combined with each other.
[0031] 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.
[0032] 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.
[0033] like Figures 1-4 As shown, this solution provides a method for repairing the shell of a top-fired hot blast stove, particularly suitable for treating shells that crack during use. This method involves adding an outer shell 3 to the outside of the cracked shell between the burner brick support 1 and the combustion chamber brick support 2. This outer shell 3 is circumferentially spliced into a single unit and welded to the original shell 4, ensuring it meets the gas pressure and gas sealing requirements of the hot blast stove. A gap 5 is left between the new outer shell 3 and the original shell 4 to maintain the gas pressure and gas sealing requirements of the hot blast stove.
[0034] In a top-fired hot blast stove, the high-temperature combustion zone is located in the combustion chamber section between the burner and the regenerator. The acidic gases produced by this high-temperature combustion condense at the furnace shell, and under the influence of air pressure, the furnace shell experiences tensile stress. The combined effect of alternating tensile stress and acid corrosion leads to stress corrosion, causing the furnace shell to crack. Therefore, this repair method is primarily applicable to furnace shell cracks located between burner brick support 1 and combustion chamber brick support 5 in top-fired hot blast stoves.
[0035] The gap between the new and old furnace shells causes air thermal resistance, which leads to an increase in the temperature of the inner furnace shell. In order to improve the strength of the inner furnace shell, the method proposes filling the gap 5 between the new outer furnace shell 3 and the original furnace shell 4 with a heat-conducting or corrosion-resistant material 6, thereby reducing the temperature of the inner furnace shell or protecting the furnace shell.
[0036] The temperature difference between the inner and outer furnace shells causes thermal stress difference, which easily pulls apart the connection welds between the inner and outer furnace shells. The method proposes setting a corrugated compensator 7 on the outer furnace shell to absorb thermal displacement and release the thermal stress difference.
[0037] The repair method proposes setting an equalizing pipe 8 on the outer furnace shell, and the equalizing gas source is taken from the cold air pipeline 10 between the cold air valve 9 and the hot blast furnace. In this way, during the air supply of the hot blast furnace, the inner furnace shell counteracts each other under the action of internal and external pressure, and the stress on the inner furnace shell will be greatly improved, which can reduce the further development of the inner furnace shell cracks.
[0038] The repair method proposes setting a thermometer 11 for temperature monitoring on the inner and outer furnace shells to monitor the working condition of the inner and outer furnace shells, and setting high and low temperature limit alarms.
[0039] Considering that the equalizing gas is prone to condensation under high pressure, the method proposes setting a drainage facility 12 at the bottom of the outer furnace shell 3, so that workers can periodically drain the condensed water.
[0040] The residual stress generated during the welding of the furnace shell is extremely prone to cause the furnace shell to crack. Therefore, the repair method proposes that the field welds of the outer furnace shell 3 should adopt measures to eliminate welding residual stress, such as annealing treatment, vibration elimination, etc.
[0041] When the temperature of the furnace shell is lower than the acid dew point temperature of the combustion gas, the acid medium will condense on the inner surface of the furnace shell and cause stress corrosion, which leads to the cracking of the furnace shell. In addition, extreme weather conditions, such as typhoons in coastal areas, can also cause a sharp change in the temperature of the furnace shell. In order to deal with these problems, the repair method proposes setting an outer protective layer 13 on the outside of the outer furnace shell 3 to keep the temperature of the outer furnace shell 3 above the acid dew point temperature and reduce the impact of extreme weather on the furnace shell. This design effectively solves the common industry problem of stress corrosion cracking of the furnace shell.
[0042] In addition, in order to ensure that the working condition of the inner furnace shell is effectively monitored, the repair method also proposes setting a device 14 for monitoring the displacement change of the inner and outer furnace shells on the outer furnace shell 3. The device can monitor the working condition of the inner furnace shell in real time and issue a warning when the inner furnace shell shows signs of failure, thereby ensuring the safe operation of the hot blast furnace.
[0043] Finally, it is explained that the above embodiments are only used to illustrate the technical solutions of the present application and are not limited. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the present application, and all should be covered in the scope of the claims of the present application.
Claims
1. A furnace shell repair structure for a top combustion hot blast stove of a blast furnace, characterized by: The application relates to a hot blast stove, which comprises an outer layer furnace shell (3) welded outside the original furnace shell (4) between the top combustion hot blast stove burner brick support (1) and the combustion chamber brick support (2), the outer layer furnace shell (3) is spliced into a whole in the circumferential direction, a gap (5) is arranged between the outer layer furnace shell (3) and the original furnace shell (4), the outer layer furnace shell (3) is used for bearing the hot blast stove gas pressure and realizing gas sealing; heat-conducting or anticorrosive material (6) is filled between the outer layer furnace shell (3) and the original furnace shell (4); a corrugated compensator (7) for absorbing thermal displacement is arranged on the outer layer furnace shell (3).
2. The furnace shell repair structure of a top combustion hot blast stove according to claim 1, characterized in that: The outer layer furnace shell (3) is provided with a pressure equalizing pipeline (8) for pressure equalization.
3. The furnace shell repair structure of a top combustion hot blast stove according to claim 2, characterized in that: A cold air pipeline (10) between the cold air valve (9) and the hot blast stove is used as a pressure equalizing gas source.
4. The furnace shell repair structure of a top combustion hot blast stove according to claim 1, characterized in that: A thermometer (11) for temperature monitoring is arranged on the outer layer furnace shell (3) and the original furnace shell (4).
5. The furnace shell repair structure of a top combustion hot blast stove according to claim 1, characterized in that: Drainage facilities (12) are arranged at the bottom of the outer layer furnace shell (3).
6. The furnace shell repair structure of a top combustion hot blast stove according to claim 1, characterized in that: Welding residual stress elimination measures are used for the field welding seams of the outer layer furnace shell (3).
7. The furnace shell repair structure of a top combustion hot blast stove according to claim 1, characterized in that: An outer protective layer (13) is arranged outside the outer layer furnace shell (3) for improving the temperature of the outer layer furnace shell (3) and avoiding the influence of extreme climate on the furnace shell.
8. The furnace shell repair structure of a top combustion hot blast stove according to claim 1, characterized in that: A device (14) for monitoring the displacement change of the inner and outer layer furnace shells is arranged on the outer layer furnace shell (3).