Plastic anti-falling wear-resistant device for secondary air port of circulating fluidized bed boiler

Abstract

The utility model relates to the field of boiler wear -resisting protection technology, concretely is CFB boiler secondary air hole plastic anti -drop wear -resisting device. The device includes main body base body, modular wear -resisting heat -insulating lining and anchoring system, and modular wear -resisting heat -insulating lining contains multistage flow guide unit and multilayer protection structure, and multistage flow guide unit realizes airflow cyclone separation through inlet flow guide blade and inner chamber cyclone chamber, and is matched with low -speed settlement material collecting groove to reduce particle scouring, and multilayer protection structure is composed of wear -resisting lining layer, thermal barrier coating and integrated porous heat -insulating layer, and has wear -resisting, high -temperature -resistant and heat -insulating functions. Anchoring system adopts high -strength anchoring body, elastic unloading layer and end porous grid -like fixed structure, fills solid -liquid phase change material in the grid, forms firm anchoring effect. The device can realize efficient protection, anti -drop, energy -conserving monitoring and convenient maintenance, solves the problems of traditional device wear and tear, thermal stress damage etc.

Description

Technical Field

[0001] This utility model relates to the field of boiler wear-resistant protection technology, specifically to a wear-resistant plastic anti-detachment device for secondary air inlets of CFB boilers. Background Technology

[0002] In circulating fluidized bed (CFB) boilers, the secondary air inlet is a key component for supplying combustion air to the furnace during combustion. The secondary air carries a large amount of high-temperature, high-speed solid particles (such as ash, slag, and bed material), which causes severe erosion and high-temperature corrosion to the refractory materials and structural components in the secondary air inlet area.

[0003] Existing protective measures typically involve laying refractory bricks, pouring refractory castables, or bonding wear-resistant ceramic sheets. These methods have the following drawbacks: First, severe wear and detachment occur; continuous scouring by high-speed particles leads to rapid wear and even complete peeling of the wear-resistant layer, affecting the safe and stable operation of the boiler. Second, traditional metal anchors are prone to creep and fatigue fracture under high temperatures and cyclical temperature changes, leading to separation of the wear-resistant layer from the substrate. The extreme high temperatures in the furnace and the drastic temperature changes caused by start-up and shutdown generate enormous thermal stress between the wear-resistant layer and the substrate, easily leading to material cracking and structural damage. Once damaged, repairs are labor-intensive, shutdowns are lengthy, and economic losses are significant.

[0004] Therefore, there is an urgent need to develop a new type of secondary air outlet protection device that integrates high efficiency, wear resistance, reliable anchoring, heat insulation, and easy maintenance. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a wear-resistant, plastic-resistant anti-detachment device for secondary air inlets of CFB boilers. This device utilizes a multi-stage flow guiding unit to create a "cyclone separation" effect, pre-separating most abrasive particles and significantly reducing the burden on the core wear-resistant layer. Combined with a multi-layered protective structure consisting of a wear-resistant lining layer, a thermal barrier coating, and a heat insulation layer, it achieves a comprehensive wear-resistant and high-temperature resistant design, encompassing both aerodynamic optimization and material protection.

[0006] This utility model is achieved using the following technical solution: CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device, including: Main body; Modular wear-resistant and heat-insulating lining is installed inside the main body; Anchoring system for securing the modular wear-resistant and thermally insulating lining to the main body; The modular wear-resistant and heat-insulating lining includes: A multi-stage flow guiding unit is used to guide and swirl the incoming airflow. The multi-stage flow guiding unit includes an inlet flow guiding pipe, inlet flow guiding blades disposed in the inlet flow guiding pipe, and an inner swirl chamber connected to the inlet flow guiding pipe. A multi-layer protective structure is set on the inner wall of the inner cavity vortex chamber, including a wear-resistant lining layer that directly resists erosion and an integrated porous heat insulation layer set on the back of the wear-resistant lining layer. The anchoring system includes: A high-strength anchor body is inserted into the main body and connected to the multi-layer protective structure; An elastic unloading layer is set between the root of the high-strength anchor body and the main body. The end has a porous mesh-like fixing structure that connects to the end of a high-strength anchor body and engages with a multi-layer protective structure.

[0007] Preferably, the porous mesh-like fixing structure at the end is filled with a solid-liquid phase change filler material that undergoes a solid-liquid phase change at a preset operating temperature. This material melts when heated, filling the tiny gaps between the anchoring structure and the wear-resistant lining, and solidifies upon cooling, forming a composite anchoring effect similar to "riveting + bonding," resulting in extremely strong anchoring force.

[0008] Preferably, the multi-stage flow guiding unit also includes a low-speed settling collection trough located below the inner cavity cyclone chamber, used to collect solid particles separated by cyclone separation, thereby reducing wear on the wear-resistant layer from the source.

[0009] Preferably, the multi-layer protective structure also includes a thermal barrier coating disposed on the furnace side of the wear-resistant lining to further enhance its resistance to high-temperature erosion.

[0010] Preferably, the modular wear-resistant and heat-insulating lining is composed of multiple modules spliced ​​together. The modules are connected and sealed with the sealing layer through module connection, which facilitates local replacement and maintenance.

[0011] Preferably, the device also includes integrated miniature heat exchange pipes for recovering waste heat lost in the area, thereby improving boiler thermal efficiency. Simultaneously, a local temperature monitor can be installed to monitor the device's operating status in real time.

[0012] It also includes a local temperature monitor for real-time monitoring of the secondary air temperature.

[0013] The low-speed settling collection trough consists of a support baffle plate and an inclined collection plate, with the inclined collection plate located above the support baffle plate.

[0014] The phase transition temperature range of solid-liquid phase change fillers is 300-600℃.

[0015] The wear-resistant lining is made of high-density alumina, silicon carbide, or silicon nitride ceramic materials.

[0016] The elastic unloading layer is made of high-temperature silicone rubber, fluororubber composite material or sintered porous ceramic.

[0017] The main body, the overall load-bearing structure of the device, is typically made of high-strength alloy steel or special refractory materials. The inlet guide duct guides secondary air into the device. Inlet guide vanes, installed inside the duct, rotate the airflow, creating a cyclone separation effect. The inner swirl chamber, working in conjunction with the vanes, further enhances the centrifugal separation of the airflow. The wear-resistant lining layer, the core wear-resistant layer directly bearing the impact of high-temperature, high-speed airflow and particulate matter, is made of high-performance ceramic materials. Thermal barrier coatings (TBCs), located on the outside of the wear-resistant lining layer, protect it from high-temperature corrosion and provide thermal insulation. An integrated porous insulation layer, located on the back of the wear-resistant lining layer, effectively blocks heat transfer to the main body. Module connection and sealing layers are used to connect the wear-resistant lining modules and ensure the sealing of the connections. High-strength anchors, key components used to firmly fix the wear-resistant lining system to the main body, are made of high-strength composite materials. The end porous mesh fixing structure, designed at the ends of the high-strength anchors, is used to fill and fix the phase change material. An elastic unloading layer, located between the anchor body and the main substrate, absorbs and buffers stress, preventing brittle fracture of the material. Miniature heat exchange pipes, integrated inside the device, recover waste heat from the vent area, achieving energy savings. A local temperature monitor monitors the temperature of key components inside the device in real time for control and optimization. A low-speed settling trough collects particles separated by the cyclone, facilitating cleanup. Support baffles, forming part of the collection trough, support and guide the particles. An inclined collection plate guides particles into the collection trough. A solid-liquid phase change filler material, a material that melts and solidifies at specific temperatures, is used to achieve a secure anchoring.

[0018] Compared with the prior art, the beneficial effects of this utility model are: (1) A "cyclone separation" effect is formed by multi-stage flow guiding units, which pre-separates most of the abrasive particles and greatly reduces the burden on the core wear-resistant layer. The multi-layer protective structure composed of wear-resistant lining, thermal barrier coating and heat insulation layer realizes a comprehensive wear-resistant and high-temperature resistant design from aerodynamic optimization to material protection.

[0019] (2) An innovative anchoring system of "solid-liquid phase change + elastic unloading" is adopted. The solid-liquid phase change material realizes micro-gap filling and integrated locking at high temperature, providing anchoring force far exceeding that of traditional mechanical anchoring. The elastic unloading layer effectively absorbs and buffers the thermal stress generated by thermal expansion mismatch, fundamentally solving the problems of anchoring failure and lining detachment caused by stress concentration.

[0020] (3) The integrated porous insulation layer effectively blocks the transfer of heat to the main substrate, protects the metal substrate structure, slows down the high-temperature aging of materials, and significantly extends the overall service life of the device. The modular design allows the replacement of wear parts to be carried out in modules without the need for large-scale dismantling and reconstruction, which greatly shortens maintenance time and costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device of this utility model; Figure 2 This is a schematic diagram of the structure of the low-speed settling collection trough of this utility model; In the diagram: 1. Main body; 2. Inlet guide pipe; 3. Inlet guide vane; 4. Inner swirl chamber; 5. Wear-resistant lining layer; 6. Thermal barrier coating; 7. Integrated porous insulation layer; 8. Module connection and sealing layer; 9. High-strength anchor body; 10. Porous mesh-like fixing structure; 11. Elastic unloading layer; 12. Miniature heat exchange pipe; 13. Local temperature monitor; 14. Low-speed settling collection trough; 15. Support baffle plate; 16. Inclined collection plate. Detailed Implementation

[0022] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0023] Example 1 like Figure 1-2As shown, the CFB boiler secondary air inlet plastic anti-detachment wear-resistant device includes: a main body 1; a modular wear-resistant and heat-insulating lining disposed within the inner cavity of the main body 1; and an anchoring system for fixing the modular wear-resistant and heat-insulating lining to the main body 1. The modular wear-resistant and heat-insulating lining includes: a multi-stage flow guiding unit for guiding and swirling the incoming airflow. This multi-stage flow guiding unit includes an inlet flow guiding pipe 2, inlet flow guiding blades 3 disposed within the inlet flow guiding pipe 2, and an inner swirling chamber connected to the inlet flow guiding pipe 2. 4. A multi-layer protective structure is disposed on the inner wall of the inner cavity cyclone chamber 4, including a wear-resistant lining layer 5 that directly resists erosion and an integrated porous heat insulation layer 7 disposed on the back of the wear-resistant lining layer 5; wherein, the anchoring system includes: a high-strength anchor body 9, which penetrates the main body 1 and is connected to the multi-layer protective structure; an elastic unloading layer 11, disposed between the root of the high-strength anchor body 9 and the main body 1; and an end porous mesh-like fixing structure 10, connected to the end of the high-strength anchor body 9 and engaging with the multi-layer protective structure. The end porous mesh-like fixing structure 10 is filled with a solid-liquid phase change filling material that undergoes a solid-liquid phase change at a preset operating temperature. The multi-stage flow guiding unit also includes a low-speed settling collection trough 14 disposed below the inner cavity cyclone chamber 4 for collecting solid particles separated by cyclone separation. The multi-layer protective structure also includes a thermal barrier coating 6 disposed on the side of the wear-resistant lining layer 5 facing the furnace. The modular wear-resistant and heat-insulating lining is composed of multiple modules spliced ​​together, which are connected and sealed with the sealing layer 8 via module connections. It also includes a miniature heat exchange pipe 12 integrated inside the device for recovering waste heat. A local temperature monitor 13 is also included for real-time monitoring of the secondary air temperature. The low-speed settling collection trough 14 consists of a supporting baffle plate 15 and an inclined collection plate 16, with the inclined collection plate 16 located above the supporting baffle plate 15.

[0024] Example 2 like Figure 1-2 As shown, the CFB boiler secondary air inlet is a plastic anti-detachment and wear-resistant device, mainly installed at the boiler's secondary air inlet. The device includes a main body 1 that serves as the overall structural support, inside which a modular wear-resistant and heat-insulating lining and an anchoring system for fixing the lining are installed.

[0025] The secondary air entering the device first passes through the inlet guide pipe 2, where the inlet guide vanes 3 are arranged in a spiral or arc shape to guide the airflow to rotate. After the rotating airflow enters the inner vortex chamber 4, due to the centrifugal force, the denser solid particles in the airflow are thrown towards the chamber wall and decelerated. Some particles can fall into the low-speed settling collection tank 14 located below, thereby achieving preliminary purification of the airflow and reducing direct impact on subsequent structures.

[0026] The pre-purified airflow continues to scour the inner wall of the inner vortex chamber 4. This inner wall has a multi-layered protective structure. The innermost layer is a wear-resistant lining layer 5, which directly bears the wear. It is made of high-hardness, high-wear-resistance high-performance ceramic materials, such as silicon carbide (SiC) or silicon nitride (Si3N4) ceramics, and is formed into a predetermined shape through processes such as hot pressing and sintering. On the side of the wear-resistant lining layer 5 facing the furnace, a thermal barrier coating 6, such as a zirconia-based ceramic coating, can be sprayed to resist high-temperature chemical corrosion and provide additional heat insulation. On the back of the wear-resistant lining layer 5, an integrated porous heat insulation layer 7 is laminated. This layer is made of foam ceramics or porous refractory materials with extremely low thermal conductivity, which can effectively prevent heat transfer to the main substrate 1. The wear-resistant lining layer 5 and the integrated porous heat insulation layer 7 can be integrally manufactured into a module. The modules are flexibly connected and sealed with a sealing layer 8, such as graphite or ceramic fiber sealing rope, through module connections, ensuring overall airtightness while also facilitating the individual replacement of damaged modules.

[0027] The key to this invention lies in its innovative anchoring system. This system is used to firmly fix the aforementioned multi-layered protective structure to the main body 1. The anchoring system includes multiple high-strength anchor bodies 9, which can be made of high-temperature resistant alloys or ceramic matrix composites. The roots of the high-strength anchor bodies 9 pass through the main body 1 for fixation, and an elastic unloading layer 11 is provided between the anchor bodies 9 and the main body 1 at their contact points. This elastic unloading layer 11 is made of elastic materials such as high-temperature silicone rubber or sintered porous ceramics, and can absorb and buffer shear stress and tensile stress caused by differences in thermal expansion coefficients through its own elastic deformation when the device is heated or cooled, preventing stress concentration from causing brittle fracture of the anchor bodies or lining.

[0028] The high-strength anchor 9 extends into the multi-layered protective structure and connects to a porous mesh-like fixing structure 10. This mesh-like structure is pre-embedded and mechanically engaged with the wear-resistant lining layer 5 and the integrated porous insulation layer 7 during manufacturing. During installation or initial heating, the solid-liquid phase change filler material, such as a low-melting-point alloy, pre-filled within the porous mesh-like fixing structure 10 melts into a liquid, filling all microscopic gaps. After the boiler temperature stabilizes or cools down, the material re-solidifies, forming a rigid locking structure that is completely integrated with the lining material and the anchor end, providing extremely strong tensile and shear resistance and completely eliminating the risk of lining detachment.

[0029] In addition, to improve energy efficiency, miniature heat exchange pipes 12 can be pre-embedded in the integrated porous insulation layer 7 or the main body 1 of the device to introduce air or water to be preheated and recover the heat lost from the air outlet. At the same time, local temperature monitors 13 (thermocouples) can be installed on the back of key locations (wear-resistant lining layer) to monitor the internal temperature of the device in real time, providing data support for boiler operation adjustment and device life prediction.

Claims

1. A wear-resistant, plastic-resistant anti-detachment device for secondary air inlets of CFB boilers, characterized in that, include: Main substrate (1); A modular wear-resistant and heat-insulating lining is provided in the inner cavity of the main body (1); An anchoring system for fixing the modular wear-resistant and heat-insulating lining to the main body (1); The modular wear-resistant and heat-insulating lining includes: A multi-stage flow guiding unit is used to guide and swirl the incoming airflow. The multi-stage flow guiding unit includes an inlet flow guiding pipe (2), an inlet flow guiding blade (3) installed in the inlet flow guiding pipe (2), and an inner cavity swirl chamber (4) connected to the inlet flow guiding pipe (2). The multi-layer protective structure is provided on the inner wall of the inner cavity vortex chamber (4), including a wear-resistant lining layer (5) that directly resists erosion and an integrated porous heat insulation layer (7) provided on the back of the wear-resistant lining layer (5). The anchoring system includes: A high-strength anchor body (9) is inserted into the main body (1) and connected to the multi-layer protective structure; An elastic unloading layer (11) is disposed between the root of the high-strength anchor solid (9) and the main body substrate (1); The end porous mesh-like fixing structure (10) is connected to the end of the high-strength anchor body (9) and engages with the multi-layer protective structure.

2. The CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device according to claim 1, characterized in that, The end porous mesh-like fixing structure (10) is filled with a solid-liquid phase change filling material that undergoes a solid-liquid phase change at a preset working temperature.

3. The CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device according to claim 1, characterized in that, The multi-stage flow guiding unit also includes a low-speed settling collection tank (14) located below the inner cavity cyclone chamber (4) for collecting solid particles separated by cyclone separation.

4. The CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device according to claim 1, characterized in that, The multi-layer protective structure also includes a thermal barrier coating (6) disposed on the side of the wear-resistant lining layer (5) facing the furnace.

5. The CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device according to claim 1, characterized in that, The modular wear-resistant and heat-insulating lining is composed of multiple modules spliced ​​together, and the modules are connected and sealed with the sealing layer (8) through module connection.

6. The CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device according to claim 1, characterized in that, It also includes a miniature heat exchange pipe (12) integrated inside the device for recovering waste heat.

7. The CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device according to claim 1, characterized in that, It also includes a local temperature monitor (13) for real-time monitoring of the temperature of the secondary air.

8. The CFB boiler secondary air inlet plastic anti-detachment and wear-resistant device according to claim 3, characterized in that, The low-speed settling collection trough (14) is composed of a support baffle plate (15) and an inclined collection plate (16), with the inclined collection plate (16) located above the support baffle plate (15).

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