Fluidized bed reactor lining and preparation method thereof

Abstract

The invention provides a fluidized bed reactor lining and a preparation method thereof, and relates to the field of photovoltaic and semiconductor industry. The lining of the fluidized bed reactor comprises at least two lining ring sections which are sequentially spliced along the axial direction of the fluidized bed reactor; the flow guide structures are obliquely arranged on the side walls of the lining ring sections or obliquely arranged on the side walls of the flow guide rings spliced between the two adjacent lining ring sections; the flow guide structure flows towards the central axis of the fluidized bed reactor and is used for guiding airflow in a near-wall area in the reactor to gather towards the center; and the interlocking structures are arranged on the end faces where every two adjacent lining ring sections are mutually folded, or arranged on the end faces where the flow guide rings and the lining ring sections are mutually folded, and used for limiting radial and circumferential relative displacement between adjacent components. The problems of purity pollution, poor structural reliability, thermal stress cracking, wall silicon deposition and the like of an existing lining can be solved, and the lining has the advantages of being high in purity, high in reliability, long in service life, convenient to maintain and the like.

Description

Technical Field

[0001] This invention relates to the photovoltaic and semiconductor industries, and more specifically, to a fluidized bed reactor liner and its preparation method. Background Technology

[0002] In the photovoltaic and semiconductor industries, the silane fluidized bed process has become the mainstream technology for producing high-purity granular silicon due to its advantages such as high automation, high production efficiency, and low energy consumption. The fluidized bed reactor, as the core equipment of this process, has its lining directly exposed to an extreme environment of high temperature (500-800℃), high pressure, corrosive reactive gases (such as silane and hydrogen), and high-speed flow of silicon particles. This requires the lining material to simultaneously possess extremely high purity (to prevent contamination of the silicon material), excellent wear resistance, corrosion resistance, high strength, and good thermal shock resistance.

[0003] Currently, most existing liners adopt an integral structure or a simple modular design. An integral structure requires complete replacement if any part is damaged, resulting in extremely high maintenance costs. Ordinary modular designs suffer from poor sealing reliability at high temperatures, making them prone to gas leaks, and the concentrated thermal stress at the joints easily leads to cracks. Furthermore, traditional liners are passive walls, unable to control airflow distribution. The retention of reactant gases in the near-wall area easily causes silicon deposition, forming scale, affecting heat transfer and flow field stability, leading to frequent reactor shutdowns for cleaning, and limiting continuous operation cycles and production efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a fluidized bed reactor liner and its preparation method, which can solve the problems of purity contamination, poor structural reliability, thermal stress cracking, silicon deposition on the wall surface and difficulty in forming large-size complex components in existing liners, and has the characteristics of high purity, high reliability, long service life and easy maintenance.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A fluidized bed reactor liner, comprising: Multiple inner lining ring segments are sequentially spliced ​​along the axial direction of the fluidized bed reactor; The flow guiding structure is inclinedly disposed on the side wall of the inner liner ring section, or inclinedly disposed on the side wall of the flow guiding ring spliced ​​between two adjacent inner liner ring sections. The flow direction of the flow guiding structure is toward the central axis of the fluidized bed reactor, and is used to guide the airflow in the near wall region of the reactor to converge toward the center. An interlocking structure is provided on the mating end faces between two adjacent inner liner ring segments, or on the mating end faces between the guide ring and the inner liner ring segment, to limit the radial and circumferential relative displacement between adjacent components.

[0006] Furthermore, the flow guiding structure includes inclined flow guiding holes or inclined flow guiding columns.

[0007] Furthermore, the angle between the central axis of the flow guiding structure and the central axis of the fluidized bed reactor is 5°-30°.

[0008] Furthermore, the angle between the central axis of the flow guiding structure and the central axis of the fluidized bed reactor is 10°-20°.

[0009] Furthermore, the interlocking structure includes a continuous coaxial sawtooth structure or a tenon and mortise structure.

[0010] Furthermore, the inner liner ring is a functionally graded composite material structure, which includes, from the inside out: a silicon carbide contact layer, a carbon fiber reinforced silicon carbide composite intermediate layer, and a silicon nitride bonded silicon carbide ceramic backing layer; wherein, the purity of the silicon carbide contact layer is ≥99.99%.

[0011] Furthermore, the outer wall of all the inner lining ring segments is covered with a continuous flexible graphite foil pad or a ceramic fiber composite pad.

[0012] Furthermore, a flexible high-temperature sealing gasket is sandwiched between the mating end faces of the interlocking structure; the inner lining ring segments are fastened together by an axial clamping mechanism, or the inner lining ring segments are fastened together with the guide ring.

[0013] Furthermore, at least one of the inner ring segments has a high-temperature sensor and / or fiber optic sensor pre-embedded in its inner wall.

[0014] A method for preparing a fluidized bed reactor liner as described above includes the following steps: Based on the pre-set three-dimensional model of the inner lining ring, the blank of the required size is obtained by 3D printing layer by layer; The green blank is placed in a graphite crucible and the required silicon raw material is added for reaction sintering treatment to obtain a silicon carbide ceramic green body. The silicon carbide ceramic preform was placed in a purification furnace containing a mixture of chlorine and hydrogen chloride gas for high-temperature purification treatment to obtain an inner lining ring segment; Multiple inner lining ring segments are sequentially spliced ​​together and fastened together by an axial clamping mechanism to obtain the reactor inner lining.

[0015] The present invention has at least the following advantages or beneficial effects: This invention achieves modularity of the liner by employing a structure in which at least two inner liner rings are sequentially spliced ​​along the reactor axis. When a local area is damaged, only the damaged single or a few rings can be replaced, without scrapping the entire liner, thus significantly reducing maintenance costs and downtime. By setting interlocking structures on the mating end faces between adjacent rings or between rings and guide rings, the relative displacement between components can be mechanically restricted in the radial and circumferential directions, thereby greatly enhancing the overall structural rigidity and connection reliability of the modular splicing, effectively resisting airflow vibration and pressure fluctuations inside the fluidized bed. By setting guide structures with the flow direction towards the reactor's central axis on the inclined sidewalls of the inner liner rings or guide rings, the reactant gas in the near-wall area can be guided to converge towards the reactor center, thereby reducing the concentration and residence time of silane gas near the reactor wall, effectively suppressing undesirable deposition of solid silicon on the reactor wall, and extending the continuous operation cycle. The reactor liner of this invention can reduce maintenance costs, enhance its own structural rigidity and connection reliability, and ensure its long-term structural stability and efficient and pure reaction environment under harsh conditions such as high temperature, erosion, and vibration. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the overall structure of a fluidized bed reactor liner provided in one embodiment of the application; Figure 2 A schematic diagram of a fluidized bed reactor liner interlocking structure with mortise and tenon joints, provided for another embodiment of the application; Figure 3 A schematic diagram of a fluidized bed reactor liner interlocking structure with a sawtooth structure, provided for another embodiment of the application.

[0018] Reference numerals in the attached drawings: 1. Inner lining ring section; 2. Flow guiding structure; 21. Flow guiding hole; 22. Flow guiding column; 3. Interlocking structure; 31. Serrated structure; 32. Mortise and tenon structure; 4. Flow guiding ring. Detailed Implementation

[0019] In analyzing existing technologies, the inventors discovered that current fluidized bed reactors, in terms of materials, suffer from several issues. Metal linings (such as high-temperature nickel alloys) are prone to metal element diffusion (iron, nickel, chromium, etc.) into the particulate silicon under high-temperature conditions, severely affecting the purity of the silicon material. While graphite linings offer good heat resistance, they suffer from carbon contamination and are prone to cracking under complex conditions due to insufficient strength. Silicon carbide coated linings face the risk of coating peeling, making long-term stable operation difficult. Furthermore, traditional linings are mostly integral structures or simple modular designs; once localized damage occurs, the entire lining usually needs to be replaced, resulting in high maintenance costs. Ordinary modular designs exhibit poor sealing performance and insufficient connection reliability under high-temperature environments, easily leading to gas leakage and thermal stress concentration problems, especially under long-term high temperatures and particle erosion, where cracks easily form at the joints. In addition, due to the significant difference in thermal expansion coefficients between the metal outer shell (commonly nickel-based alloys) and the ceramic lining (such as silicon carbide), enormous thermal stress is generated during equipment heating and cooling, potentially causing the lining to crack or separate from the outer shell. Example 1

[0020] Please refer to Figures 1-3 The figure shown is a schematic diagram of the structure of the fluidized bed reactor liner in an embodiment of the present invention; This embodiment provides a fluidized bed reactor liner, comprising at least two inner liner ring segments 1. Multiple inner liner ring segments 1 are sequentially spliced ​​along the axial direction of the fluidized bed reactor to form a complete cylindrical inner wall. This segmented design allows for the replacement of only the damaged ring segment in case of localized damage, such as in the easily worn lower area, significantly reducing maintenance costs and downtime. Adjacent inner liner ring segments 1 can be directly spliced ​​together or connected using connecting components, such as the guide ring 4 described below.

[0021] In this embodiment, to address the wall deposition problem, a flow guiding structure 2 is provided in the liner. This flow guiding structure 2 can be implemented in two ways: one is to be directly inclined on the side wall of the liner ring 1; the other is to be inclined on the side wall of the flow guiding ring 4 spliced ​​between two adjacent liner rings 1. Regardless of the method, the flow direction of the flow guiding structure 2 is towards the central axis of the fluidized bed reactor. When a portion of the reactant gas flows through these inclined channels, the flow direction is changed, generating a velocity component pointing towards the center of the reactor. This oblique airflow disturbs and guides the main airflow in the near-wall region to converge towards the center, thereby reducing the silane gas concentration and residence time in the region close to the reactor wall, effectively suppressing undesirable silicon deposition on the wall surface, and making the reaction more concentrated on the silicon seed crystal particles in the center of the bed.

[0022] It should be noted that the implementation method of using an independent guide ring 4 has the advantage of maintaining the structural integrity and mechanical strength of the inner lining ring segment 1, avoiding stress concentration caused by opening holes in the body, and is particularly suitable for occasions with extremely demanding strength requirements.

[0023] As a preferred embodiment, the specific form of the flow guiding structure 2 can be an inclined flow guiding hole 21 opened on the side wall of the inner lining ring 1 or the flow guiding ring 4, or a flow guiding column 22 inclinedly inserted into the side wall. The end of the flow guiding column 22 located inside the inner lining can extend a certain distance into it, thereby expanding the physical range of airflow guidance.

[0024] The angle between the central axis of the aforementioned flow guiding structure 2 and the central axis of the fluidized bed reactor is preferably 5°-30°, more preferably 10°-20°. This range can achieve the best balance between effective flow guidance and not excessively disturbing the main flow field.

[0025] In this embodiment, to ensure the rigidity and sealing reliability of the modular splicing, an interlocking structure 3 is provided on the mating end faces between two adjacent inner liner ring segments 1, or on the mating end faces between the independent guide ring 4 and the inner liner ring segment 1. The interlocking structure 3 is used to limit the relative displacement between adjacent components in the radial and circumferential directions.

[0026] In a preferred embodiment, the interlocking structure 3 is a continuous coaxial sawtooth structure 31 or a tenon and mortise structure 32. For example, continuous concentric raised tenons or sawtooths can be machined on the lower end face of the upper ring segment, and matching recessed mortises or sawtooths can be machined on the upper end face of the lower ring segment. During assembly, the tenons are precisely embedded in the mortises, or the sawtooths mesh with each other. This design not only achieves strong radial and circumferential mechanical interlocking, but also forms a tortuous sealing path, effectively improving the structural stability and airtightness of the connection parts under high temperature, high pressure and vibration environments.

[0027] To further ensure sealing, a sealing gasket made of high-temperature resistant flexible ceramic fiber, such as alumina fiber, can be sandwiched between the mating end faces of the interlocking structure 3. During assembly, a final tightening mechanism, such as a set of long bolts or a central tie rod system evenly arranged along the circumference, is used for final fastening. The tightening force compresses and deforms the gasket, compensating for microscopic unevenness of the mating surfaces and continuously compensating for some thermal stress, thus ensuring excellent airtightness between the ring segments even under harsh operating conditions.

[0028] In this embodiment, to systematically address the issues of material strength, thermal shock resistance, and thermal compatibility with the outer shell, the inner liner ring 1 is preferably a functionally graded composite material structure. This structure, from the inside out, comprises a silicon carbide contact layer, a carbon fiber reinforced silicon carbide composite intermediate layer, and a silicon nitride-bonded silicon carbide ceramic backing layer. The silicon carbide contact layer has a purity ≥99.99% and a thickness of 3-5 mm. As the working surface directly in contact with the reaction environment, it provides the highest chemical inertness, wear resistance, and corrosion resistance, fundamentally eliminating contamination. The carbon fiber reinforced silicon carbide composite intermediate layer, with a thickness of 15-25 mm, utilizes the excellent toughening effect of carbon fiber to significantly improve the overall fracture toughness and thermal shock resistance of the ring, preventing brittle fracture. The silicon nitride-bonded silicon carbide ceramic backing layer, with a thickness of 8-12 mm, has a lower coefficient of thermal expansion that is closer to that of the metal outer shell. As a thermal expansion transition zone between the inner liner and the outer shell, it can significantly reduce interfacial stress caused by the mismatch in their coefficients of thermal expansion.

[0029] To further alleviate the thermal stress between the ceramic liner and the metal shell, a continuous flexible graphite foil pad or ceramic fiber composite pad can be laid on the outer wall of all liner ring sections 1. As an integral thermal expansion buffer layer, this flexible layer can effectively absorb and compensate for dimensional differences generated during temperature rise and fall, protecting the liner structure.

[0030] To achieve condition monitoring and intelligent control, high-temperature sensors (such as thermocouples) and / or fiber optic sensors can be pre-embedded in the inner wall of at least one inner lining ring segment 1 for real-time monitoring of temperature and strain, and to achieve early warning.

[0031] This application also provides a method for preparing the above-mentioned fluidized bed reactor liner. This method integrates advanced processes such as 3D printing, reaction sintering densification, and gas-phase purification, and includes the following steps: Green body forming: Based on the pre-designed 3D model of the inner liner segment 1, a green body of the required size is obtained by 3D printing layer by layer. Specifically, this involves importing the designed ceramic model into a 3D printing machine and using 3D printing technology to form the green body of the required size from silicon carbide powder layer by layer. The silicon carbide powder used is ordinary grade silicon carbide micro powder with a particle size of 0.5-5μm. The designed inner liner model is a barrel-shaped structure with a diameter of 500mm. The upper and lower edges of the inner liner are equipped with matching interfaces and connecting blocks to facilitate the connection and positioning of adjacent inner liners. This step uses 3D printing technology to prepare silicon carbide ceramic green bodies, overcoming the technical difficulties of forming large-size, multi-curved flow channel structure ceramic materials, and enabling continuous mass production in the industrial industry. The 3D printing technology uses selective laser sintering technology.

[0032] Reaction sintering: The green blank is placed in a graphite crucible, and the required silicon raw material is added for reaction sintering to obtain a silicon carbide ceramic green body. Specifically, the green blank is placed in a graphite crucible, and the silicon raw material required for reaction sintering, consisting of silicon particles with a particle size of 1-5 μm, is piled around it. The sintering program is started, and reaction sintering is carried out in a sintering device at a sintering temperature of 1600°C for 2 hours. After cooling, the green body is obtained. This step obtains a silicon carbide green body through sintering. During sintering, a silicon infiltration reaction occurs, improving the density and strength of the material. The impurity content of the green body is controlled below 500 ppm.

[0033] High-temperature purification: The silicon carbide ceramic green body was placed in a purification furnace containing a mixture of chlorine and hydrogen chloride gas for high-temperature purification treatment to obtain the inner lining ring segment 1. Specifically, the obtained green body was placed in a purification furnace with a high-temperature atmosphere controllable furnace and a microwave heating system for purification. Purification was carried out using a flowing atmosphere of mixed chlorine and hydrogen chloride gas at a gas flow rate of 10 L / min, a purification temperature of 1200°C, and a purification time of 50 h. After purification treatment, a high-purity silicon carbide material inner lining part was obtained with an impurity content of 100 ppm.

[0034] Assembly and connection: Multiple inner liner ring segments 1 are spliced ​​together in sequence and fastened together by an axial clamping mechanism to obtain the reactor liner, with a total assembly height of 1000mm.

[0035] The technical solution of the present invention will be described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0036] Example 1: A fluidized bed reactor liner with a diameter of 1200 mm and a total height of 2000 mm. This embodiment provides a liner for a medium-sized fluidized bed reactor. The liner is composed of four integrally formed annular liner segments (numbered A, B, C, and D from top to bottom) stacked axially. Each segment has a height of 500 mm. Each liner segment employs a functionally graded composite material design: an inner layer of 5 mm thick ultra-high purity sintered α-silicon carbide contact layer (99.995% purity); a middle layer of 20 mm thick carbon fiber braided reinforced silicon carbide (C / SiC) composite material; and an outer layer of 10 mm thick silicon nitride-bonded silicon carbide (Si3N4-SiC) ceramic backing layer. This graded structure is formed in a precision mold through layered laying and single-stage reaction sintering.

[0037] On the mating end faces of ring A (lower end face), ring B (upper end face), rings B and C (between end faces), and rings C and D (between end faces), continuous concentric serrated structures are machined using a precision grinding machine as an interlocking structure. The tooth height is 5mm and the tooth pitch is 10mm. Before assembly, a 2mm thick alumina fiber braided flexible high-temperature sealing gasket is placed between each serrated mating surface. After aligning the four rings, 12 heat-resistant alloy long bolts evenly distributed around the circumference of the inner liner are used as an axial clamping mechanism. A preload is applied to fasten the rings together as a whole. After tightening, the serrations mesh with each other, achieving a firm radial and circumferential lock, while the compressed gasket ensures high-temperature airtightness at the connection.

[0038] In this embodiment, the flow guiding structure adopts an integrated design. A series of inclined flow guiding holes are ultrasonically processed on the inner wall surface of each liner ring (A, B, C, D). These flow guiding holes are evenly distributed on the ring wall surface, with their central axis forming a 15° angle with the central axis of the fluidized bed reactor, and a diameter of 3 mm. When the reactant gas flows through, some of the gas passes through these inclined holes, changing its flow direction and generating a flow component pointing towards the center. This effectively guides the airflow near the wall region towards the center of the bed, inhibiting wall deposition. The assembled liner is then placed inside the reactor's metal alloy shell. Before placement, a 1 mm thick flexible expanded graphite foil is tightly wrapped around the entire outer wall surface of the liner as an integral thermal expansion buffer layer to absorb and compensate for the thermal expansion difference stress between the two. Example 2: A method for preparing an inner liner with an independent flow guide ring

[0039] 3D Printed Blank: The designed 3D model of a single inner liner segment (including a pre-set interlocking serrated structure) is imported into a laser selective sintering 3D printer. High-purity silicon carbide powder with an average particle size of 1μm is used as raw material. Parameters such as laser power and scanning speed are set, and the blank is printed layer by layer to obtain a silicon carbide blank with accurate dimensions and complete structure.

[0040] Reaction sintering: Multiple printed green blanks are placed together into a large graphite crucible, and high-purity silicon powder with a particle size of 1-3 μm is filled around the green blanks. The crucible is pushed into a high-temperature sintering furnace, and after vacuuming, it is filled with argon gas for protection. The temperature is increased to 1600°C at a rate of 5°C / min and held at that temperature for 2 hours for reaction sintering. During the sintering process, liquid silicon permeates into the pores of the green blanks, and the reaction Si + C → SiC occurs, achieving complete densification of the green blank and obtaining a high-strength silicon carbide ceramic green blank with a density of over 98% of the theoretical density.

[0041] Gas-phase purification: The sintered green body is transferred to a microwave high-temperature purification furnace. A mixture of chlorine and hydrogen chloride gas at a flow rate ratio of 1:1 is introduced into the furnace, with the total flow rate controlled at 10 L / min. The furnace temperature is raised to 1200°C and maintained at this temperature for 50 hours. During this process, trace amounts of metallic impurities such as Fe, Al, and Ca remaining in the green body react with the chlorine / hydrogen chloride gas to generate volatile chlorides such as FeCl3 and AlCl3, which are carried away by the gas flow. After purification, the total content of metallic impurities in the green body is reduced to below 80 ppm, and the purity of silicon carbide is higher than 99.99%.

[0042] Assembly: Three inner liner ring segments, each 333 mm high, prepared using the above method, and two independent silicon carbide guide rings with 15° inclined airflow channels (placed between ring segments 1-2 and 2-3 respectively), are aligned according to an interlocking structure. Alumina fiber gaskets are placed between all mating surfaces, and then secured with eight circumferentially distributed high-temperature alloy bolts, finally assembling a complete inner liner with a total height of approximately 1000 mm.

[0043] Effect verification: The liner of this invention was installed in a silane fluidized bed reactor for continuous operation testing. Compared with reactors using conventional monolithic silicon carbide liner: The metal impurity content in the produced granular silicon was reduced by an order of magnitude, reaching electronic grade standards. After six months of continuous operation, an inspection revealed smooth walls with no obvious silicon deposits; in contrast, the control group showed significant scale buildup on the walls after three months. Simulated damage to the lower ring section allowed for partial replacement and restart within 24 hours; a complete replacement of the control group took more than a week. After 200 cycles of rapid cooling and heating from room temperature to 750°C, the liner of this invention showed no cracks or peeling; the traditional liner developed microcracks after only 50 cycles.

[0044] The above embodiments demonstrate that the fluidized bed reactor liner and its preparation method provided by the present invention have excellent comprehensive performance and can effectively meet the stringent requirements of high-purity particulate silicon production for equipment liner.

[0045] The beneficial effects of the embodiments of this application are as follows: Axial modular design supports partial replacement, significantly reducing maintenance costs and time. The inclined flow-guiding structure actively optimizes the near-wall flow field, effectively suppressing silicon wall deposition, reducing downtime for cleaning, and improving equipment utilization and capacity. The combination of end-face interlocking structure, axial clamping, and flexible gaskets provides extremely high three-dimensional structural rigidity and high-temperature sealing, adapting to the vibration environment of fluidized beds. The synergistic design of functionally graded materials and flexible buffer layers systematically solves the cracking and separation problems caused by thermal stress, ensuring long-term operational reliability. The 3D printing combined with reaction sintering and gas-phase purification fabrication route successfully realizes the manufacturing of complex high-purity silicon carbide ceramic components, laying the foundation for industrialization.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fluidized bed reactor lining, characterized in that, The reactor liner comprises: a plurality of inner liner ring segments, which are sequentially spliced along the axial direction of the fluidized bed reactor; a flow guide structure, which is obliquely arranged on the side wall of the inner liner ring segment or the side wall of the flow guide ring spliced between two adjacent inner liner ring segments; the flow direction of the flow guide structure is towards the central axis of the fluidized bed reactor, and the flow guide structure is used for guiding the gas flow in the near-wall region of the reactor to converge towards the center; an interlocking structure, which is arranged on the mutually abutting end faces of two adjacent inner liner ring segments or the mutually abutting end faces of the flow guide ring and the inner liner ring segment, and is used for limiting the radial and circumferential relative displacement between adjacent components.

2. The fluidized bed reactor liner of claim 1, wherein, The flow guide structure comprises inclined flow guide holes or inclined flow guide columns.

3. The fluidized bed reactor liner of claim 2, wherein, The included angle between the central axis of the flow guide structure and the central axis of the fluidized bed reactor is 5°-30°.

4. The fluidized bed reactor liner of claim 3, wherein, The included angle between the central axis of the flow guide structure and the central axis of the fluidized bed reactor is 10°-20°.

5. The fluidized bed reactor liner of claim 1, wherein, The interlocking structure comprises a continuous coaxial heart-shaped sawtooth structure or a mortise and tenon structure.

6. The fluidized bed reactor liner of claim 1, wherein, The inner liner ring segment is a functionally graded composite material structure, which comprises, from inside to outside, a silicon carbide contact layer, a carbon fiber reinforced silicon carbide composite intermediate layer and a silicon nitride bonded silicon carbide ceramic backing layer; wherein the purity of the silicon carbide contact layer is ≥99.99%.

7. The fluidized bed reactor liner of claim 1, wherein, The outer wall of all the inner liner ring segments is paved with a continuous flexible graphite foil pad or a ceramic fiber composite pad.

8. The fluidized bed reactor liner of claim 1, wherein, A flexible high-temperature sealing gasket is clamped between the mutually abutting end faces of the interlocking structure; the inner liner ring segments are fastened and connected through an axial compression mechanism.

9. The fluidized bed reactor liner of claim 1, wherein, The inner wall of at least one of the inner liner ring segments is pre-buried with a high-temperature sensor and / or an optical fiber sensor.

10. A method of producing a fluidized bed reactor lining according to any one of claims 1 to 9, characterized in that The method comprises the following steps: based on a preset three-dimensional model of the inner liner ring segment, a green body with a required size is formed through 3D printing layer by layer; the green body is placed in a graphite crucible and is put into a required silicon raw material for reaction sintering treatment to obtain a silicon carbide ceramic body; the silicon carbide ceramic body is placed in a purification furnace containing a mixed gas of chlorine and hydrogen chloride for high-temperature purification treatment to obtain an inner liner ring segment; a plurality of the inner liner ring segments are sequentially spliced and fastened and connected through an axial compression mechanism to obtain a reactor liner.

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