A segmented inner cylinder of a supercritical water oxidation reactor

Abstract

The utility model discloses a sectional type inner tube of supercritical water oxidation reactor, including shell, inner tube, the inner tube is installed in the shell, and the inside space of inner tube is the reaction interval and the quenching interval, and the space between the outer wall of inner tube and the inner wall of shell is cooling jacket, the inner tube is the sectional structure, including upper inner tube and lower inner tube, and upper inner tube and lower inner tube are detachably connected, and the inside of upper inner tube is the reaction interval, and the inside of lower inner tube is the quenching interval.

Description

Technical Field

[0001] This invention relates to a segmented inner cylinder for a supercritical water oxidation reactor. Background Technology

[0002] Nuclear power plant operation and maintenance generate large quantities of radioactive organic hazardous waste, such as waste lubricating oil, spent fuel extraction waste liquid, waste cleaning solvents, high-concentration organic condensate wastewater, and recalcitrant organic waste liquid. This hazardous waste containing radionuclides cannot be treated using traditional incineration methods, as this would create aerosols containing radionuclides that would diffuse into the atmosphere. Due to a lack of safe, environmentally friendly, and efficient treatment technologies, this type of radioactive organic hazardous waste currently has to be stored in large quantities and for extended periods within nuclear power plants, posing a significant safety and environmental hazard to nuclear power operations and urgently requiring a solution. The frequent international nuclear contamination incidents in recent years have further highlighted the importance of this issue. Radioactive hazardous waste typically cannot be transferred to other locations for treatment; therefore, it is necessary to establish independent radioactive organic hazardous waste treatment facilities at each nuclear power plant.

[0003] The construction costs of existing international radioactive organic waste treatment systems are extremely high, often exceeding hundreds of millions of yuan per unit, with substantial ongoing maintenance costs. More importantly, nuclear power plants, as critical facilities involving sensitive information, have highly sensitive technical details that cannot rely on external technologies and treatment facilities. Furthermore, advanced nuclear power-related technologies have been designated as key export control and restriction areas by some technologically advanced regions. Therefore, developing supercritical water oxidation (SCWO) technology and equipment with completely independent intellectual property rights, controllable construction and maintenance costs, and suitable for treating radioactive organic waste from nuclear power plants is of great significance in the following ways.

[0004] Supercritical water oxidation (SCWO) technology, with its ability to efficiently and thoroughly oxidize organic pollutants under high temperature and high pressure, has been widely used in high-risk industrial fields such as nuclear power plant operation and maintenance, fine chemicals, and organic hazardous waste treatment. In the SCWO reaction system, the reactor is the core device, and its structural design directly affects the system's thermal stability, safety, operating efficiency, and maintenance feasibility.

[0005] Traditional supercritical water oxidation reactors often employ a one-piece structure design for their inner cylinders. While this provides a certain level of strength, it presents significant technical limitations in actual high-temperature and high-pressure operation. On one hand, the one-piece structure hinders modular zoning of the system, making it difficult to achieve functional independence and temperature control separation between the reaction zone and the quenching zone. On the other hand, the overall structure is complex to disassemble and assemble, and inconvenient for inspection and maintenance. Especially when scaling, blockage, or fatigue damage to internal components occurs, disassembly and replacement operations are costly and time-consuming, impacting system operating efficiency.

[0006] In addition, in traditional inner cylinder structures, the cooling system support usually relies on a single ring support or a nested outer shell structure, which has insufficient support stability. This makes components such as cooling coils prone to loosening, displacement, or even corrosion and leakage during operation, affecting cooling efficiency and system reliability.

[0007] Therefore, how to construct a segmented inner cylinder structure that is structurally detachable, has clearly defined functional zones, strong support stability, and is easy to maintain has become a key technical challenge in the current design of supercritical water oxidation reactors. Utility Model Content:

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a segmented inner cylinder for a supercritical water oxidation reactor.

[0009] A segmented inner cylinder for a supercritical water oxidation reactor includes an outer shell and an inner cylinder. The inner cylinder is installed inside the outer shell. The inner space of the inner cylinder serves as a reaction zone and a quenching zone. The space between the outer wall of the inner cylinder and the inner wall of the outer shell serves as a cooling jacket. The inner cylinder has a split structure, including an upper inner cylinder and a lower inner cylinder, which are detachably connected. The interior of the upper inner cylinder is the reaction zone, and the interior of the lower inner cylinder is the quenching zone.

[0010] Furthermore, the upper inner cylinder and the lower inner cylinder are connected by a threaded structure, with an external thread at the bottom of the upper inner cylinder and an internal thread at the top of the lower inner cylinder.

[0011] Furthermore, the upper inner cylinder is equipped with a cooling coil for indirect heat exchange with the reactants during the reaction process, thereby reducing the reaction temperature.

[0012] Furthermore, the lower inner cylinder is provided with a quenching inner tube, the top of which extends to the middle of the lower inner cylinder and has several evenly distributed quenching liquid outlet holes for injecting quenching liquid to mix and exchange heat with the reaction products, thereby rapidly reducing the discharge temperature.

[0013] Furthermore, a ring of evenly distributed support ribs is welded to the upper end of the inner wall of the lower inner cylinder, and support hole plates are installed on the support ribs.

[0014] Furthermore, the support plate is welded with a ring of evenly distributed coil supports for supporting the cooling coils in the upper inner cylinder; the support plate can also be used to fill the catalyst bed in the upper inner cylinder according to process requirements; the support plate has several through holes for the reaction materials to pass through.

[0015] Furthermore, the support plate is a two-piece assembly, with a coil hole at the assembly seam, so that after the cooling coil is installed, it can be installed on the support rib plate. The straight pipe section at the bottom of the cooling coil passes through the coil hole and communicates with the coil coolant inlet, which is located at the bottom of the outer shell.

[0016] Beneficial effects: Compared with the prior art, this utility model focuses on the operating characteristics of supercritical water oxidation reactor under high temperature, high pressure and complex fluid conditions, and optimizes the structural configuration of the inner cylinder and outer shell. It has significant technical advantages, especially in terms of structural disassembly, modular assembly and internal support stability.

[0017] Firstly, this invention adopts a dual-separation structure of outer shell and inner cylinder. The outer shell consists of a cylinder body, an upper end cap, and a lower end cap, which are connected by welding and flanges to achieve both strong sealing and convenient disassembly and assembly of the reactor. The inner cylinder consists of an upper inner cylinder and a lower inner cylinder, forming modular functional zones. The upper inner cylinder is the reaction zone, and the lower inner cylinder is the quenching zone. The clear structural boundaries facilitate independent optimization of temperature control strategies and cooling mechanisms for different zones. The detachable connection design significantly simplifies the reactor's manufacturing and subsequent maintenance processes, reducing maintenance difficulty and costs.

[0018] Secondly, the upper inner cylinder and the lower inner cylinder are connected by a threaded structure, and the lower inner cylinder and the lower end cap are connected by welding, which facilitates the disassembly and installation of other components in the inner cylinder.

[0019] In addition, a ring of evenly distributed support ribs is provided at the upper end of the inner wall of the lower inner cylinder. Two modular support perforated plates are installed on the support ribs. This support structure is easy to disassemble and is used to support other components inside the inner cylinder. On the other hand, it can also be used to fill the catalyst bed according to process requirements.

[0020] In summary, this invention optimizes the functional layout, installation process, and internal stability design of the reactor through a segmented inner cylinder structure. This not only facilitates manufacturing and maintenance but also enhances the structural pressure-bearing capacity and the flexibility of the cooling system layout. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the supercritical water oxidation reactor in a specific embodiment.

[0022] Figure 2 This is a schematic diagram of the support perforated plate in a specific embodiment;

[0023] In the diagram, 1 is the outer shell, 2 is the cooling jacket, 3 is the cooling coil, 4 is the reaction zone, 5a is the upper inner cylinder, 5b is the lower inner cylinder, 6 is the supporting rib, 7 is the supporting perforated plate, 8 is the coil bracket, 9 is the coil coolant inlet, 10 is the quench zone, 11 is the quench inner tube, 12 is the quench outlet, 13 is the coil hole, 14 is the through hole, and 15 is the quench coolant inlet. Detailed Implementation

[0024] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0025] A supercritical water oxidation reactor for treating organic hazardous waste generated during nuclear power plant operation and maintenance includes an outer shell 1 and an inner cylinder. The inner cylinder is installed inside the outer shell 1. The inner space of the inner cylinder is a reaction zone 4 and a quench zone 10. The space between the outer wall of the inner cylinder and the inner wall of the outer shell 1 is a cooling jacket 2. The inner cylinder has a split structure, including an upper inner cylinder 5a and a lower inner cylinder 5b, which are detachably connected. The upper inner cylinder 5a contains the reaction zone 4, and the lower inner cylinder 5b contains the quench zone 10.

[0026] This embodiment divides the reactor's internal space into upper and lower sections using a segmented inner cylinder, serving as the reaction zone 4 and quench zone 10, respectively. The inner cylinder is installed inside the outer shell 1, forming a multi-layered structure. The interlayer between the outer shell 1 and the inner cylinder constitutes a cooling jacket 2, used to remove the heat of reaction. During operation, the reactants first undergo supercritical water oxidation in the upper inner cylinder 5a, generating products and releasing heat. They then enter the lower inner cylinder 5b, where the temperature is rapidly reduced in the quench zone 10, bringing the reaction products to the required discharge temperature. Both the upper and lower inner cylinders 5a and 5b are detachable, facilitating inspection, maintenance, and replacement of internal components, as well as catalyst loading / replacement and coil cleaning.

[0027] This structural design enables efficient thermal management and reaction control in the supercritical water oxidation process: the clear boundary between the reaction zone and the quenching zone facilitates the optimization of reaction conditions and cooling efficiency respectively; the split design facilitates assembly and disassembly, improving the maintainability and adaptability of the equipment; the spatial partitioning of the upper and lower inner cylinders also facilitates the independent arrangement of the catalyst bed and the quenching system, improving the flexibility of the process and the overall performance.

[0028] In one possible implementation, the upper inner cylinder 5a and the lower inner cylinder 5b are connected by a threaded structure, with the bottom of the upper inner cylinder 5a having an external thread and the top of the lower inner cylinder 5b having an internal thread.

[0029] Threaded connections simplify the assembly process and improve the assembly efficiency of segmented inner cylinders. Simultaneously, they allow for quick disassembly during equipment inspection, maintenance, component replacement, or cleaning, significantly enhancing maintenance convenience and service life. Furthermore, threaded connections provide excellent sealing, effectively preventing leakage and ensuring the safety and stability of the reaction system.

[0030] In one possible implementation, the upper inner cylinder 5a is provided with a cooling coil 3 for indirect heat exchange with the reactants during the reaction process, thereby reducing the reaction temperature.

[0031] This structure improves temperature control accuracy, effectively controlling the heating rate and peak temperature during the reaction process, thus enhancing the controllability and safety of the reaction.

[0032] In one possible implementation, the lower inner cylinder 5b is provided with a quenching inner tube 11, the top of which extends to the middle of the lower inner cylinder 5b and has several evenly distributed quenching liquid outlet holes 12 for injecting quenching liquid to mix and exchange heat with the reaction products, thereby rapidly reducing the discharge temperature.

[0033] The rapid cooling inner tube structure significantly improves the cooling speed, and the liquid outlet design enables uniform cooling, avoiding local liquid accumulation and overheating, which helps to improve the overall stability and safety of the system.

[0034] In one possible implementation, a ring of evenly distributed support ribs 6 is welded to the upper end of the inner wall of the lower inner cylinder 5b, and a support perforated plate 7 is installed on the support ribs 6. A ring of evenly distributed coil supports 8 is welded to the support perforated plate 7 to support the cooling coils 3 in the upper inner cylinder 5a. The support perforated plate 7 has several through holes 14 for the passage of reaction materials.

[0035] The supporting stiffener 6 is welded to the inner wall of the lower inner cylinder 5b to form a stable supporting platform. The supporting perforated plate 7 is installed on the supporting stiffener, which can bear the weight of the upper structure and provide mechanical support, providing a stable installation platform for the internal structure such as the cooling coil 3 and the catalyst bed.

[0036] This structure enhances the overall support of the internal components of the reactor and improves structural stability; the evenly distributed support ribs 6 effectively disperse the stress, prevent local deformation, and extend the equipment life; the support perforated plate 7 can serve as a platform for installing functional components, and has multiple supporting functions, thus optimizing the structural integration.

[0037] In one possible implementation, the support plate 7 is a two-piece assembly, with a coil hole 13 at the assembly seam, so that after the cooling coil 3 is installed, it can be installed on the support rib plate 6. The straight pipe section at the bottom of the cooling coil 3 passes through the coil hole 13 and communicates with the coil coolant inlet 9, which is located at the bottom of the outer casing 1.

[0038] The support plate 7 is designed as a modular structure, usually consisting of two symmetrical pieces, either left-right or top-bottom. This structure facilitates the gradual assembly of components, reduces installation difficulties caused by space constraints, and significantly simplifies the assembly process of the cooling coil 3. The cooling coil will not be damaged during assembly, thus improving reliability. At the same time, it facilitates later maintenance and replacement, reduces maintenance costs, and improves operational efficiency.

[0039] Working Principle: The segmented inner cylinder of this supercritical water oxidation reactor achieves stable reaction and efficient cooling under high temperature and high pressure through a multi-layered structure and functional zoning mechanism. Its basic structure consists of an outer shell 1 and an inner cylinder, which includes an upper inner cylinder 5a and a lower inner cylinder 5b, which are detachably connected. The upper inner cylinder 5a serves as the reaction zone 4, and is equipped with cooling coils 3 for indirect heat exchange to remove reaction heat. The lower inner cylinder 5b serves as the quenching zone 10, and is equipped with a quenching inner tube 11 and a quenching outlet hole 12. By injecting quenching liquid, a mixing heat exchange is achieved, rapidly reducing the discharge temperature of the reaction products.

[0040] During overall operation, the reactants first enter the upper inner cylinder 5a for supercritical water oxidation, releasing a large amount of heat. This heat is transferred through the cooling jacket 2 and cooling coil 3 via indirect heat exchange, controlling the reaction temperature within a safe range. Subsequently, the reaction products flow through the support orifice plate 7 into the lower inner cylinder 5b. Based on the product temperature, an appropriate amount of quenching liquid is automatically injected for mixing and heat exchange, rapidly cooling the product to the required discharge temperature. The entire system utilizes a threaded or modular design to ensure stable connections between components and ease of maintenance, achieving synergistic optimization of reaction heat control, material flow, and system structure.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A segmented inner cylinder for a supercritical water oxidation reactor, characterized in that, The device includes an outer shell and an inner cylinder. The inner cylinder is installed inside the outer shell. The inner space of the inner cylinder is a reaction zone and a rapid cooling zone. The space between the outer wall of the inner cylinder and the inner wall of the outer shell is a cooling jacket. The inner cylinder has a split structure, including an upper inner cylinder and a lower inner cylinder. The upper inner cylinder and the lower inner cylinder are detachably connected. The interior of the upper inner cylinder is the reaction zone, and the interior of the lower inner cylinder is the rapid cooling zone.

2. The segmented inner cylinder according to claim 1, characterized in that, The upper inner cylinder and the lower inner cylinder are connected by a threaded structure. The bottom of the upper inner cylinder is provided with an external thread, and the top of the lower inner cylinder is provided with an internal thread.

3. The segmented inner cylinder according to claim 1, characterized in that, The upper inner cylinder is equipped with a cooling coil, which is used for indirect heat exchange with the reactants during the reaction process to reduce the reaction temperature.

4. The segmented inner cylinder according to claim 1, characterized in that, The lower inner cylinder is equipped with a quenching inner tube. The top of the inner tube extends to the middle of the lower inner cylinder and has several evenly distributed quenching liquid outlet holes for injecting quenching liquid to mix and exchange heat with the reaction products, thereby rapidly reducing the discharge temperature.

5. The segmented inner cylinder according to claim 1, characterized in that, A ring of evenly distributed support ribs is welded to the upper end of the inner wall of the lower inner cylinder, and support holes are installed on the support ribs.

6. The segmented inner cylinder according to claim 5, characterized in that, The support plate is welded with a ring of evenly distributed coil supports to support the cooling coils in the upper inner cylinder; the support plate can also be used to fill the catalyst bed in the upper inner cylinder according to process requirements; the support plate has several through holes for the reaction materials to pass through.

7. The segmented inner cylinder according to claim 6, characterized in that, The support plate consists of two assembled pieces, with a coil hole at the assembly seam. After the cooling coil is installed, it is mounted on the support rib. The straight pipe section at the bottom of the cooling coil passes through the coil hole and communicates with the coil coolant inlet, which is located at the bottom of the outer casing.

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