Deslagging pipe

Abstract

The utility model provides a slag discharging pipe. The slag discharging pipe comprises an inner pipe, an outer pipe and a heat insulation layer arranged between the inner pipe and the outer pipe in a filling mode. The inner pipe is a pipeline made of rare earth heat-resistant steel and is used for being in contact with high-temperature slag and guiding the high-temperature slag to be discharged; the outer pipe is a pipeline made of an SS310 stainless steel material, is arranged outside the inner pipe and is used for providing structural support and external protection; the heat insulation layer is a heat insulation pouring material filled in an annular cavity between the inner pipe and the outer pipe; a plurality of annular supporting ribs are further arranged between the inner pipe and the outer pipe, the annular supporting ribs are arranged at intervals in the length direction of the slag discharging pipe, the annular supporting ribs are wrapped in a heat insulation layer formed through pouring, and a dredging hole communicated with the interior of the slag discharging pipe is formed in the pipe wall of the outer pipe. The slag discharging pipe is high in overall thermal deformation resistance, and the pipe body is more stable to use under the high-temperature working condition and is not prone to deformation.

Description

Technical Field

[0001] This application relates to the field of boiler equipment technology, and in particular to a slag discharge pipe. Background Technology

[0002] With the widespread adoption of circulating fluidized bed boilers in industrial heating and combined heat and power (CHP) applications, their high-efficiency combustion characteristics and adaptability to complex coal qualities have become crucial supporting technologies for large-scale boiler systems. During long-term boiler operation, the slag discharge system not only serves to promptly remove high-temperature slag from the furnace but also acts as a vital channel connecting the high-temperature furnace and the low-temperature treatment system, bearing complex heat loads and stress environments. Especially under intermittent slag discharge and fluctuating high-temperature and high-pressure conditions, the slag discharge pipes are constantly exposed to extreme thermal erosion and high-temperature radiation, making their structural reliability and durability key factors restricting the overall safety and efficiency of the boiler operation.

[0003] Existing circulating fluidized bed boilers generally use single-layer SS310 stainless steel slag discharge pipes, which are simple in structure and easy to manufacture. They are typically wrapped with an outer layer of insulation material to reduce heat loss. However, in actual use, because the slag discharge pipes are directly exposed to the high-temperature slag flow path in the lower part of the furnace, the metal pipes are continuously subjected to direct scouring and heat radiation from the high-temperature slag during long-term operation, making them highly susceptible to high-temperature aging. Common problems include: the metal wall turning red, embrittlement, thermal deformation, and even cracking and breakage. Once the slag discharge pipe fails, it not only causes slag leakage and seal failure but may also damage the boiler structure and even force the system to shut down for maintenance, seriously affecting the continuous and stable operation of the unit.

[0004] Therefore, existing slag discharge pipe structures are generally prone to high-temperature aging and structural embrittlement and deformation under long-term high-temperature service conditions. This has become a major hidden danger affecting the safe and stable operation of boilers, and there is an urgent need to propose more reasonable thermal protection and high-temperature failure resistance solutions from the structural level. Utility Model Content

[0005] This application provides a slag discharge pipe to solve the problem that existing circulating fluidized bed boiler slag discharge pipes are prone to high-temperature aging and red-hot embrittlement and deformation under long-term high-temperature slag scouring, which affects safe slag discharge.

[0006] This application provides a slag discharge pipe, which includes an inner pipe, an outer pipe, and a heat insulation layer filled between the inner pipe and the outer pipe;

[0007] The inner pipe is a rare-earth heat-resistant steel pipe made by casting, used to contact high-temperature slag and guide its discharge; the outer pipe is a pipe made of SS310 stainless steel, set outside the inner pipe, used to provide structural support and external protection; the heat insulation layer is a heat insulation castable filling the annular cavity between the inner and outer pipes; multiple annular support ribs are also provided between the inner and outer pipes, the annular support ribs are arranged at intervals along the length of the slag discharge pipe, the annular support ribs are covered in the cast heat insulation layer, and the outer pipe wall has a dredging hole that communicates with the inside of the slag discharge pipe.

[0008] In one optional embodiment, the annular support rib is a circular annular plate structure made of metal material, the outer diameter of which matches the inner diameter of the outer tube, and the inner diameter of which matches the outer diameter of the inner tube.

[0009] In one optional embodiment, the number of the annular support ribs is not less than three, and they are evenly distributed along the axial direction of the slag discharge pipe.

[0010] In one optional embodiment, the number of unblocking holes is at least two, and one unblocking hole is provided on the pipe wall at each of the two ends of the outer pipe along its length. Unblocking pipes are provided at the unblocking holes, and the ends of the unblocking pipes are provided with openable and closable sealing caps.

[0011] In one alternative embodiment, the insulation layer is made of an alumina-based or aluminosilicate casting material.

[0012] In one optional embodiment, the inner tube is composed of multiple inner tube segments, adjacent inner tube segments are connected by positioning rings or mating edges, and each segment is formed sequentially using a segmented casting process.

[0013] In one optional embodiment, the outer pipe is provided with mounting flanges at both ends for connection with other pipe sections in the boiler ash discharge system.

[0014] In one optional embodiment, the inner and outer pipes are kept coaxially connected by multiple annular support ribs, and the slag discharge pipe is cylindrical in shape.

[0015] Compared with the prior art, this application has the following beneficial effects:

[0016] 1. The slag discharge pipe provided in this application adopts a composite structure consisting of an inner pipe, an insulation layer, and an outer pipe, unlike the traditional single-layer metal slag discharge pipe which is directly exposed to the scouring of high-temperature slag. The inner pipe is made of rare-earth heat-resistant steel through casting. Compared with conventional heat-resistant steel, it has stronger structural stability and better oxidation resistance in high-temperature environments, and is less prone to structural embrittlement under long-term slag scouring. Moreover, the dense inner wall structure formed by casting also improves the inner surface's resistance to high-temperature slag flow, helping to slow down the material aging and deformation process caused by high temperature, and providing a more reliable slag guiding support foundation for the slag discharge channel.

[0017] 2. This application incorporates a heat insulation layer between the inner and outer pipes, which reduces heat transfer to the external structure and decreases the overall thermal load on the slag discharge pipe. This insulation layer, made of high-temperature heat-resistant casting material, is filled into the annular cavity between the two pipe layers, forming a continuous protective structure with thermal resistance. This weakens the heat transfer effect of the high-temperature environment on the outer pipe and surrounding structure to a certain extent. Furthermore, the presence of the insulation layer helps to smooth the internal temperature gradient, reducing structural deformation and fatigue damage caused by thermal stress or instantaneous temperature differences. Simultaneously, the insulation layer adheres closely to the inner pipe during construction, helping to support and position the inner pipe, thus maintaining a relatively stable slag guiding state during operation and reducing the risks of flow channel deviation and blockage.

[0018] 3. This application incorporates multiple annular support ribs between the inner and outer pipes. These ribs are evenly spaced along the axial direction of the slag discharge pipe and are integrally embedded within the insulation layer, providing radial support while maintaining the coaxial distance between the inner and outer pipes. This support structure exhibits strong structural integrity under hot conditions and provides support for the insulation layer under gravity, thermal expansion and contraction, or operational vibrations, thus reducing structural imbalance caused by localized collapse. This design enhances the overall thermal deformation resistance of the slag discharge pipe, making the pipe more stable under high-temperature conditions. This reduces the risk of pipe cracking, overheating, and embrittlement caused by structural instability, thermal stress concentration, or uneven heat conduction, which positively impacts the continuity and operational safety of the high-temperature slag discharge system. Attached Figure Description

[0019] 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a slag discharge pipe provided in one embodiment of this application;

[0021] Figure 2 An overall external schematic diagram of a slag discharge pipe provided in an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the insulation layer of the slag discharge pipe between the inner and outer pipes, provided in an embodiment of this application.

[0023] Explanation of reference numerals in the attached figures:

[0024] 100-Inner pipe; 200-Outer pipe; 300-Insulation layer; 400-Annular support rib; 500-Unblocking hole; 600-Unblocking pipe; 700-Sealing cap; 800-Mounting flange. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0026] Please see Figures 1-3 This application provides a slag discharge pipe, aiming to improve the structural durability of the slag discharge pipe and the safety of boiler operation. The slag discharge pipe provided in this application is suitable for slag discharge channel structures in circulating fluidized bed boilers or similar high-temperature furnaces. Figures 1-3 As shown, the slag discharge pipe of this embodiment specifically includes an inner pipe 100, an outer pipe 200, and a heat insulation layer 300 filled between the inner pipe 100 and the outer pipe 200.

[0027] The inner pipe 100 is a pipe made of cast rare earth heat-resistant steel, used to contact high-temperature slag and guide its discharge; the outer pipe 200 is a pipe made of SS310 stainless steel, set outside the inner pipe 100, used to provide structural support and external protection; the heat insulation layer 300 is a heat insulation castable filling the annular cavity between the inner pipe 100 and the outer pipe 200; multiple annular support ribs 400 are also provided between the inner pipe 100 and the outer pipe 200, the annular support ribs 400 are arranged at intervals along the length of the slag discharge pipe, and the annular support ribs 400 are covered in the cast heat insulation layer 300; the outer pipe 200 has a dredging hole 500 on its wall that communicates with the inside of the slag discharge pipe.

[0028] In this embodiment, the slag discharge pipe adopts a composite structure consisting of an inner pipe 100, a heat insulation layer 300, and an outer pipe 200, unlike the traditional single-layer metal slag discharge pipe which is directly exposed to the scouring of high-temperature slag. The inner pipe 100 is made of rare earth heat-resistant steel through casting. Compared with conventional heat-resistant steel, it has stronger structural stability and better oxidation resistance in high-temperature environments. It also has stronger heat scouring resistance and is less prone to structural embrittlement under long-term slag scouring conditions. Moreover, the dense inner wall structure formed by casting also improves the inner surface's resistance to high-temperature slag flow, helping to slow down the material aging and deformation process caused by high temperatures, and providing a more reliable slag guiding support foundation for the slag discharge channel.

[0029] To reduce heat transfer to the external structure and decrease the overall heat load of the slag discharge pipe, a heat insulation layer 300 is provided between the inner pipe 100 and the outer pipe 200 in this embodiment. This heat insulation layer 300 can be filled in the annular cavity between the two pipe layers using a high-temperature heat-resistant casting material. Compared with traditional insulation cotton or board insulation structures, this structure avoids localized uneven heat conduction caused by interlayer gaps, forming a continuous protective structure with thermal resistance, thus weakening the heat conduction effect of the high-temperature environment on the outer pipe 200 and surrounding structures to a certain extent. Furthermore, the presence of the heat insulation layer 300 helps to smooth the internal temperature gradient, reducing structural deformation and fatigue damage caused by thermal stress or instantaneous temperature differences. Since the high-temperature heat source is confined around the inner pipe 100, the outer pipe 200 is significantly less heated. The outer pipe 200 is made of SS310 stainless steel, which has high mechanical strength. Under the protection of the inner pipe 100, the outer pipe 200 can more easily provide stable support and protection under reduced heat load. Meanwhile, the insulation layer 300 is closely attached to the inner tube 100 during construction, which helps to support and position the inner tube 100, thereby maintaining a relatively stable slag guiding state during operation and reducing the risk of flow channel deviation and blockage.

[0030] In addition, multiple annular support ribs 400 are arranged between the inner tube 100 and the outer tube 200. These annular support ribs 400 are evenly spaced along the axial direction of the slag discharge pipe and are integrally embedded in the insulation layer 300, forming multi-point support in structure. This provides a stable radial positioning relationship between the inner and outer tubes, maintaining the coaxial distance between the inner and outer tubes while providing radial support. This support structure exhibits strong structural retention capacity under hot conditions and can support the insulation layer 300 under gravity, thermal expansion and contraction, or operational vibration, which helps reduce structural imbalance caused by local collapse. Through this design, the overall thermal deformation resistance of the slag discharge pipe is improved, and the pipe body is more stable under high-temperature conditions, thereby reducing the risk of pipe cracking, red-hot, embrittlement, and other failures caused by structural instability, thermal stress concentration, or uneven heat conduction. This has a positive effect on improving the continuity and operational safety of the high-temperature slag discharge system. Meanwhile, in this embodiment, multiple unblocking holes 500 communicating with the interior of the slag discharge pipe are provided on the wall of the outer pipe 200, which facilitates unblocking and maintenance of the slag discharge pipe during operation, thereby reducing the risk of blockage. Optionally, the slag discharge pipe is arranged at an angle.

[0031] In practical applications, slag discharge pipes are typically arranged at a certain angle to create a guiding slope between them and the horizontal plane. This arrangement helps to guide the high-temperature slag out of the boiler body using gravity, reducing the residence time of the slag inside the pipe. Inclined installation improves slag discharge efficiency and reduces the risk of blockage caused by slag stagnation or backflow. Furthermore, the inclined layout facilitates unblocking operations, allowing accumulated slag to naturally settle into a lower, easier-to-clean area, thereby improving the operational stability and maintenance convenience of the entire slag discharge system.

[0032] In some embodiments, the annular support rib 400 is a circular annular plate structure made of metal material, the outer diameter of which matches the inner diameter of the outer tube 200, and the inner diameter of which matches the outer diameter of the inner tube 100.

[0033] In this embodiment, the annular support rib 400 adopts a circular annular plate structure and is made of metal. This structure has good circumferential symmetry, which can conduct and distribute thermal and mechanical stress more evenly during hot operation, thus reducing the risk of thermal expansion deformation caused by stress concentration in local areas. In terms of size design, the outer diameter of the annular support rib 400 matches the inner diameter of the outer tube 200, while the inner diameter fits tightly with the outer diameter of the inner tube 100. This not only allows the annular support rib to be accurately positioned during assembly, thus ensuring its stable holding in the annular space between the inner and outer tubes during the pouring of the insulation layer 300, but also allows the annular support rib 400 to serve as a limiting template structure during the construction of the insulation layer 300, playing a role in constraining the boundary and supporting the shape during the pouring of the insulation layer 300.

[0034] After the insulation layer 300 cures, the annular support rib 400 is completely encased within it, forming a multi-position support system. This support method is characterized by its annular, coaxial, and multi-group arrangement, which not only improves the overall stability of the composite pipeline structure but also helps maintain the relative positional relationship between the inner and outer pipes when facing thermal expansion or vibration conditions. As an important connection and load-bearing core, the annular support rib 400 can effectively suppress the eccentric changes of the inner pipe during operation, delaying problems such as structural displacement and asymmetrical wear caused by thermal stress fluctuations or uneven loads. This helps to improve the flow stability of the slag discharge channel and the service life of the entire pipeline.

[0035] In some embodiments, the number of annular support ribs 400 is not less than three, and they are evenly distributed along the axial direction of the slag discharge pipe.

[0036] In the above embodiments, the annular support ribs 400 are evenly arranged along the length of the slag discharge pipe, thus forming multiple circumferential connection nodes between the inner pipe 100 and the outer pipe 200. This arrangement of the support structure not only provides structural symmetry but also improves the free expansion state of the inner pipe 100 during thermal expansion and contraction, allowing for a more uniform release of thermal stress along the axial direction and reducing the risk of local warping and deformation caused by uneven stress gradients. During the casting of the insulation layer 300, the evenly distributed annular support ribs also act as template limiters, enhancing the shape retention capability of the casting area. This results in a denser insulation layer 300 with better structural continuity, reducing the probability of quality defects such as voids and honeycombing.

[0037] Furthermore, this embodiment, by setting the number of annular support ribs 400 to no less than three and adopting an axially uniform distribution, not only improves the support balance of the tube structure under static stress conditions, but also helps to enhance its vibration resistance during boiler operation. During slag discharge, a certain degree of flow impact and vibration disturbance often occurs. With the annular support ribs 400 evenly distributed along the axis, multiple stable support points are formed, which can play a damping role in dispersing vibration loads, thereby delaying the initiation of fatigue cracks caused by frequent micro-vibrations. In addition, each annular support rib 400 participates in the connection stabilization task between the inner tube 100 and the outer tube 200 during operation, helping to maintain structural coordination under alternating hot and cold conditions, further reducing the possibility of coaxial deviation or directional imbalance in the slag discharge channel.

[0038] In some embodiments, the number of unblocking holes 500 is at least two, and an unblocking hole 500 is provided on the pipe wall at each of the two ends of the outer pipe 200 along its length. An unblocking pipe 600 is provided at the unblocking hole 500, and the end of the unblocking pipe 600 is provided with an openable and closable sealing cap 700.

[0039] In this embodiment, at least two unblocking holes 500 are provided at both ends of the outer pipe 200, and they are distributed along the length of the slag discharge pipe. This structural layout provides a convenient double-end unblocking passage for the slag discharge channel. During the operation of the slag, whether there is upstream deposition or downstream blockage, intervention can be made through the unblocking hole on the closer side. This setting can greatly reduce the occurrence of unblocking dead corners, making the entire slag discharge pipe more maintainable under complex working conditions.

[0040] Furthermore, in this embodiment, a dredging pipe 600 is provided at each dredging hole 500. This design not only avoids the dredging operation opening being directly exposed on the outer wall of the pipe, but also provides an externally extending operation opening for cleaning operations. The dredging pipe 600 can be used to insert a slag removal rod, an air guiding device, or other auxiliary tools to achieve a safer and more convenient slag removal operation. During the dredging process, the pipe structure can also play a certain guiding role, reducing the risk of slag splashing or high-temperature gas backflow, thereby making the slag removal operation safer for operators, and also helping to reduce environmental pollution caused by dust escape.

[0041] Furthermore, this embodiment features an openable and closable sealing cap 700 at the end of the unblocking pipe 600. This cap can be used to seal the unblocking opening in a non-maintenance state, limiting the leakage of high-temperature gas and slag, while also blocking the path of backflow of external moisture or foreign objects. The sealing cap 700 is designed to be easily opened during equipment inspections or occasional blockages, and then closed again after unblocking.

[0042] In some embodiments, the insulation layer 300 is made of alumina-based or aluminosilicate casting material.

[0043] In this embodiment, alumina-based or aluminosilicate castable materials are selected as the constituent materials of the insulation layer 300. Both types of materials possess high thermal stability and good thermal shock resistance. Alumina-based materials have a high melting point and low thermal conductivity, which can effectively suppress the outward transfer of heat borne by the inner pipe 100 under high-temperature conditions, reduce the heat load in the area where the outer pipe 200 is located, and help alleviate stress concentration caused by temperature differences in the structure. Aluminosilicate materials, on the other hand, possess certain flexibility and crack resistance, and can maintain the integrity of the insulation layer structure under alternating hot and cold conditions. Compared with traditional ceramic fiber, plate-shaped insulation, or non-cast materials, these materials perform better in terms of high-temperature resistance and anti-stripping properties, which is beneficial to improving the stability of the slag discharge pipe during long-term operation.

[0044] Meanwhile, the casting process for constructing the insulation layer 300 facilitates the uniform filling of alumina-based or aluminosilicate materials into the annular cavity between the inner tube 100 and the outer tube 200. The material, poured in a liquid or semi-fluid state, possesses excellent fluidity, spontaneously filling structural gaps and dead corners to form a tightly bonded, continuous, and dense insulation layer. During construction, the segmented positioning effect of the annular support ribs 400 results in an overall structure exhibiting a "skeleton support + encapsulation filling" form, reducing the probability of common defects such as delamination and interface separation. Compared to methods such as flexible winding and plate insertion, the cast insulation structure exhibits higher bonding strength and molding consistency, and stronger retention under heat.

[0045] Furthermore, the optimized material selection in this embodiment further enhances the durability and operational safety of the slag discharge pipe. Alumina-based and aluminosilicate casting materials possess excellent resistance to chemical corrosion, are not prone to pulverization, carbonization, or structural damage, and have a relatively low coefficient of thermal expansion, making them more compatible with the thermal expansion behavior of the inner pipe 100 made of rare-earth heat-resistant steel. This helps alleviate the accumulation of interfacial thermal strain, reduces the risk of hot cracking, and further maintains the structural stability between the inner pipe 100 and the outer pipe 200, giving the entire composite pipeline higher adaptability and safety performance under high-temperature operation.

[0046] In some optional embodiments of this application, the inner tube 100 is composed of multiple inner tube segments, adjacent inner tube segments are connected by positioning rings or mating edges, and each segment is formed sequentially by a segmented casting process.

[0047] In this embodiment, the inner tube 100 is composed of multiple inner tube segments. This segmented structure offers greater flexibility and facilitates processing, transportation, and hoisting, making it particularly suitable for scenarios with compact boiler layouts or complex slag discharge channel routes. By splicing multiple inner tube segments together, the manufacturing process is simplified while ensuring channel continuity, providing conditions for potential partial replacements or maintenance, thereby reducing the economic burden and on-site construction workload of overall replacement.

[0048] In practical applications, adjacent inner pipe sections can be connected via positioning rings or mating edges to achieve automatic structural docking and self-positioning. This connection method helps to achieve axial centering and misalignment suppression of the inner pipe sections during installation, reducing problems such as eccentricity and bending caused by manual assembly errors. The positioning rings also have limiting and supporting functions, making the interface more stable.

[0049] After the inner pipe 100 sections are installed, the insulation layer 300 is constructed using a segmented casting process. This construction strategy allows for better control of the material flow and solidification process within each segment, enabling workers to promptly remove air bubbles and adjust the flow direction, reducing defects such as voids or slag inclusions caused by single-stage pouring. Simultaneously, short intermittent buffer phases can be set between sections to reduce stress accumulation on the overall structure caused by sudden temperature changes during pouring. Compared to single-stage pouring, the segmented process offers advantages in quality control and on-site construction adaptability, improving the density and structural consistency of the insulation layer 300, thereby enhancing the overall stability and service reliability of the entire pipe under high-temperature operation.

[0050] In some embodiments, the outer pipe 200 is provided with mounting flanges 800 at both ends for connection with other pipe sections in the boiler ash discharge system.

[0051] In the above embodiment, mounting flanges 800 are provided at both ends of the outer pipe 200, giving the slag discharge pipe a standardized interface form, which facilitates connection with other components (such as transfer pipes, valves, etc.) in the boiler slag discharge system. The flange structure conforms to common pipe interface specifications in terms of size and hole type design, has strong adaptability, and can be matched with corresponding specifications according to the structural requirements of different slag discharge systems, thereby improving the versatility of the product in actual engineering.

[0052] Furthermore, the 800 flange, as a surface contact structure, can form a stable sealing interface with a gasket, maintaining a good seal even under high-temperature operating conditions and preventing high-temperature gases or slag from leaking into the external environment. Compared to welded connections, flange connections have a certain buffering capacity against axial stress and can maintain higher connection stability under thermal expansion and contraction, making them suitable for operating systems with large temperature fluctuations.

[0053] During later use and maintenance, the installation of flange 800 also provides greater convenience for disassembly, assembly, and repair operations. When the slag discharge pipe becomes blocked, corroded, or suffers localized structural damage during long-term operation, the entire pipe or a single section of the slag discharge pipe can be quickly removed and replaced by loosening the flange connection.

[0054] In some embodiments, the inner pipe 100 and the outer pipe 200 are coaxially arranged by a plurality of annular support ribs 400, and the slag discharge pipe is a cylindrical pipe as a whole.

[0055] In the above embodiment, the inner pipe 100 and the outer pipe 200 are supported and positioned by multiple annular support ribs 400, ensuring that the two pipe layers maintain a uniform spacing in the radial direction, thus forming a relatively coaxial composite structure. This coaxial arrangement not only helps to form a standardized annular thermal insulation space between the inner and outer pipes, avoiding uneven structural stress caused by local eccentricity, but also facilitates a relatively symmetrical distribution of thermal stress under hot operation, thereby reducing the risk of warping deformation caused by uneven heating. The balanced layout of the annular gaps also facilitates the uniform filling of the insulation layer 300 during construction, improving the consistency of the pouring thickness, helping to form a dense thermal insulation coating layer, and enhancing the overall thermal stability and thermal barrier effect.

[0056] Furthermore, the entire slag discharge pipe structure is a cylindrical pipe, which has good geometric symmetry and uniform stress distribution, making it easy to use with standardized interfaces (such as flanges and clamps), thereby simplifying the design difficulty of system integration. The cylindrical structure also has certain fluid-friendly characteristics during the slag guiding process. The regular internal channels and low resistance help high-temperature slag to be discharged smoothly in the pipe, reducing local slag accumulation and blockage caused by uneven cross-sections or channel offsets.

[0057] The following is a reference method for using the slag discharge pipe according to the embodiments of this application, as detailed below:

[0058] Before the slag discharge pipe in this embodiment is put into use, it must be sealed and connected to the connecting pipe in the boiler slag discharge system through the mounting flanges 800 at both ends of the outer pipe 200. During installation, it is necessary to check whether the flange is equipped with a sealing gasket and whether the bolts are tightened evenly to avoid the risk of air leakage due to unstable connection. When the slag discharge pipe is in place, it should be kept at the design-required tilt angle to facilitate the smooth discharge of slag and avoid a decrease in slag discharge efficiency due to installation deviation. The inner pipe 100 and the outer pipe 200 are positioned and connected by multiple annular support ribs 400 to form a double-layer composite structure, which maintains structural stability in the installed state.

[0059] During boiler operation, the high-temperature slag generated in the furnace flows into the slag discharge channel through the inner pipe 100. Since the inner pipe 100 is made of cast rare-earth heat-resistant steel, it can withstand slag erosion and heat radiation at high temperatures, helping to slow down red-hot deformation. The insulation layer 300 between the inner pipe 100 and the outer pipe 200 is a cast-type high-temperature insulation material with excellent thermal resistance, effectively isolating heat conduction and reducing the thermal expansion and contraction of the outer pipe 200, thereby enhancing the overall structural thermal stability. During operation, if a decrease in slag discharge speed or blockage is observed, the location of the unblocking hole 500 can be checked periodically, the sealing cap 700 on the corresponding unblocking pipe 600 can be opened, and a cleaning tool can be inserted to unblock the blockage and maintain unobstructed slag discharge.

[0060] When the system enters shutdown or scheduled maintenance mode, the slag discharge pipe can be quickly removed by loosening the mounting flange 800, allowing for internal inspection and necessary maintenance. If wear is detected in the inner pipe section, the designated area can be replaced in sections or partially recast for repair.

[0061] As can be seen from the above description, the slag discharge pipe of this application embodiment has the characteristics of stable structure and smooth slag guidance during operation, and has good maintainability and adaptability, making it suitable for continuous operation under high-temperature slag discharge conditions.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A slag discharge pipe, characterized in that, The slag discharge pipe includes an inner pipe, an outer pipe, and a heat insulation layer filled between the inner pipe and the outer pipe; The inner pipe is a rare-earth heat-resistant steel pipe made by casting, used to contact high-temperature slag and guide its discharge; the outer pipe is a pipe made of SS310 stainless steel, set outside the inner pipe, used to provide structural support and external protection; the heat insulation layer is a heat insulation castable filling the annular cavity between the inner and outer pipes; multiple annular support ribs are also provided between the inner and outer pipes, the annular support ribs are arranged at intervals along the length of the slag discharge pipe, the annular support ribs are covered in the cast heat insulation layer, and the outer pipe wall has a dredging hole that communicates with the inside of the slag discharge pipe.

2. The slag discharge pipe according to claim 1, characterized in that, The annular support rib is a circular plate structure made of metal material, with its outer diameter matching the inner diameter of the outer tube and its inner diameter matching the outer diameter of the inner tube.

3. The slag discharge pipe according to claim 1 or 2, characterized in that, The number of annular support ribs shall not be less than three, and they shall be evenly distributed along the axial direction of the slag discharge pipe.

4. The slag discharge pipe according to claim 1, characterized in that, The number of unblocking holes is at least two. One unblocking hole is provided on the pipe wall at each end of the length direction of the outer pipe. Unblocking pipes are provided at the unblocking holes, and the ends of the unblocking pipes are provided with openable and closable sealing caps.

5. The slag discharge pipe according to claim 1, characterized in that, The insulation layer is made of alumina-based or aluminosilicate casting material.

6. The slag discharge pipe according to claim 1, characterized in that, The inner tube is composed of multiple inner tube segments, which are connected by positioning rings or mating edges. Each segment is formed sequentially using a segmented casting process.

7. The slag discharge pipe according to claim 1, characterized in that, The outer tube is provided with mounting flanges at both ends.

8. The slag discharge pipe according to claim 1, characterized in that, The inner and outer pipes are kept coaxial by multiple annular support ribs, and the slag discharge pipe is cylindrical in shape.

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