Polysilicon cold hydrogenation fluidized bed reactor

Abstract

The utility model relates to the technical field of polycrystal silicon, especially to a polycrystal silicon cold hydrogenation fluidized bed reactor, which comprises a reactor main body, the bottom wall of which is provided with a gas inlet channel, the side wall is provided with a powder inlet channel, and the top wall is provided with an exhaust channel; the reactor main body is internally provided with a gas distribution plate, a bubble breaker and a support plate; the utility model is provided with a support plate below the bubble breaker, which improves the overall structural rigidity of the bubble breaker and effectively bears dynamic impact load, and makes the stress distribution more uniform, thereby effectively preventing the bubble breaker from collapsing; the partition plate in the support plate cuts large bubbles, solving the problem that the bubble cutting in the prior art excessively depends on the bubble breaker.

Description

Technical Field

[0001] This utility model relates to the field of polycrystalline silicon technology, and in particular to a polycrystalline silicon cold hydrogenation fluidized bed reactor. Background Technology

[0002] Fluidized bed reactors are commonly used in polysilicon production. The primary process within a fluidized bed reactor is cold hydrogenation, which converts silicon powder, a byproduct of polysilicon production, into the useful gaseous product trichlorosilane. In a fluidized bed reactor, a mixture of hydrogen and silicon tetrachloride is introduced from the bottom, fluidizing the silicon powder particles. Fluidization enhances gas-solid contact and mass transfer efficiency, significantly accelerating the chemical process of silicon powder reacting with silicon tetrachloride and hydrogen to form trichlorosilane. However, as the gas rises, bubbles form. These bubbles can escape before complete reaction, preventing adequate mixing and resulting in low reaction efficiency and low conversion rates.

[0003] To address the aforementioned technical problems, existing technologies typically incorporate a bubble breaker in the fluidized bed reactor. This bubble breaker is composed of several baffles joined together. The bubble breaker breaks up rising bubbles into smaller bubbles, thereby increasing the gas-solid contact area and promoting a uniform distribution of the gas-solid two-phase flow, ultimately significantly improving reaction efficiency.

[0004] However, in practical applications, it has been found that the continuous impact of fluidized silicon powder on the breaker under high-speed airflow, coupled with gas pressure fluctuation loads, leads to the collapse of the breaker structure. This problem is particularly prominent in large-size fluidized beds (Φ≥4.5m). Due to the intense and uneven flow of the fluid, the breaker is exposed to a high-velocity, high-particle-concentration environment for a long time, resulting in a significant increase in the gas-solid two-phase impact force, making it more prone to fatigue deformation and even overall collapse. Furthermore, in existing technologies, bubble cutting relies excessively on the breaker. Once the breaker malfunctions, a large amount of gas will escape without sufficient reaction, reducing reaction efficiency and making it difficult to meet the requirements of modern high-efficiency production. Utility Model Content

[0005] The purpose of this invention is to provide a polycrystalline silicon cold hydrogenation fluidized bed reactor to solve the problems mentioned in the background art.

[0006] The technical solution adopted in this utility model is:

[0007] The polycrystalline silicon cold hydrogenation fluidized bed reactor includes:

[0008] The reactor body is provided with a gas inlet channel, a powder inlet channel and an exhaust channel. The reactor body is provided with a gas distribution plate, a bubble breaker and a support plate.

[0009] The gas distribution plate is located above the gas inlet channel, and the bubble breaker is located above the gas distribution plate;

[0010] Wherein,

[0011] The support plate is located below the bubble breaker for supporting the bubble breaker and cutting the bubbles;

[0012] The support plate includes:

[0013] A support main body, one end of which is arranged on one inner wall of the reactor main body, and the other end extends to the opposite inner wall of the reactor main body and is connected to the other inner wall;

[0014] A partition plate, arranged on the support main body.

[0015] Optionally, the height of the support main body is equal to the height of the partition plate.

[0016] Optionally, one end of the support main body is fixedly arranged on one inner wall of the reactor main body, and the other end extends to the opposite inner wall of the reactor main body and is movably connected to the other inner wall.

[0017] Optionally, a plurality of connecting seats are fixedly arranged on the inner wall of the reactor main body, and each connecting seat is provided with a long circular hole through which a connecting hole is opened at the other end of the support main body corresponding to the long circular hole.

[0018] Optionally, the support plate is 5-8 mm away from the bubble breaker.

[0019] Optionally, the bubble breaker is mainly arranged by arranging a plurality of bubble-breaking units, which are arranged in layers along the inner wall of the reactor main body. The shape of the bubble breaker is adapted to the inner wall of the reactor main body, and the setting directions of every two adjacent bubble-breaking units are perpendicular to each other.

[0020] Optionally, the number of layers of the bubble breaker is multiple, and the number of the support plates is 3 groups, which respectively correspond to the top 3 layers of the bubble breaker.

[0021] Optionally, the bubble-breaking unit includes:

[0022] A frame body, in a square shape;

[0023] A plurality of bubble-breaking plates, arranged on the frame body.

[0024] Optionally, the bubble-breaking plates are arranged inside the frame body in an inclined manner.

[0025] Optionally, the directions of the bubble-breaking plates at the same part of every two adjacent layers of the bubble breaker are opposite.

[0026] Compared with the prior art, the beneficial effects of this utility model are:

[0027] This invention provides a support plate below the bubble breaker, which improves the overall structural rigidity of the bubble breaker and effectively withstands dynamic impact loads, while also making the stress distribution more uniform, thereby effectively preventing the bubble breaker from collapsing. The support plate also cuts large bubbles by using a partition, solving the problem of excessive reliance on the bubble breaker for bubble cutting in the prior art. Attached Figure Description

[0028] 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the overall structure of this application;

[0030] Figure 2 This is a top view of the bubble deflator in this application;

[0031] Figure 3 This is a schematic diagram of the overall structure and cross-sectional structure of the bubble-breaking unit in this application;

[0032] Figure 4 This is a schematic diagram of the overall structure of the support plate in this application;

[0033] Figure 5 This is a schematic diagram of the overall structure of the connector in this application;

[0034] Figure 6 This is a schematic diagram showing the positional relationship between the reactor body, support plate, and connecting seat in this application;

[0035] Figure 7 This is a schematic diagram showing the positional relationship between the bubble breaker, support plate, and connecting seat in this application;

[0036] Figure 8 This is a schematic diagram showing the direction of the bubble-breaking plates at the same location in two adjacent bubble-breaking layers in this application.

[0037] Figure label:

[0038] 1. Reactor body; 11. Gas inlet channel; 12. Powder inlet channel; 13. Exhaust channel;

[0039] 2. Gas distribution plate;

[0040] 3. Bubble breaker; 31. Bubble breaking unit; 311. Frame; 312. Bubble breaking plate; 313. First flow zone;

[0041] 4. Support plate; 41. Support body; 411. Connecting hole; 42. Partition plate; 43. Second flow area;

[0042] 5. Connecting base; 51. Connecting plate; 52. Oblong hole;

[0043] 6. Double-ended bolt; 7. Nut. Detailed Implementation

[0044] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0045] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0046] Currently, fluidized bed reactors suffer from problems such as bubble breaker collapse and excessive reliance on bubble breakers for bubble cutting.

[0047] like Figures 1-8 As shown in the figure, this utility model embodiment provides a polycrystalline silicon cold hydrogenation fluidized bed reactor, mainly including: a reactor body 1 and a gas distribution plate 2, a bubble breaker 3, and a support plate 4 disposed inside the reactor body 1. The bottom wall of the reactor body 1 is provided with a gas inlet channel 11, the side wall is provided with a powder inlet channel 12, and the top wall is provided with an exhaust channel 13.

[0048] The reactor body 1 is roughly tank-shaped and is configured as the main site for the cold hydrogenation reaction.

[0049] The gas distribution plate 2 is located above the gas inlet channel 11 and is configured to uniformly disperse the gas introduced into the reactor body 1. The dispersed gas passes through the reactor body 1 from bottom to top, so that the silicon powder inside the reactor body 1 is in a fluidized state, and at the same time, it receives a very small amount of unreacted silicon powder (after the fluidized bed reactor stops operating, the very small amount of unreacted silicon powder falls back to the gas distribution plate 2 under the action of gravity).

[0050] The bubble breaker 3 is located above the gas distribution plate 2 and is configured to break the rising bubbles into smaller bubbles, thereby increasing the gas-solid contact area and promoting the uniform distribution of the gas-solid two-phase flow.

[0051] The support plate 4 is located below the bubble breaker 3 and is configured to improve the overall structural rigidity of the bubble breaker 3 and effectively withstand dynamic impact loads, making the stress distribution more uniform and thus effectively preventing the bubble breaker 3 from collapsing. It also cuts the bubbles.

[0052] Specifically, such as Figure 1 As shown, the bubble breakers 3 are fixedly arranged in a layered structure on the inner wall of the reactor body 1, and their overall outline is adapted to the curved surface of the inner wall of the reactor body 1. Preferably, in this embodiment, the number of bubble breakers 3 is 12 layers, which are distributed at intervals from bottom to top inside the reactor body 1. Figure 2 As shown, each bubble deflator 3 is mainly composed of multiple bubble deflator units 31 arranged together, and the arrangement directions of each pair of adjacent bubble deflator units 31 are perpendicular to each other.

[0053] Specifically, such as Figure 3 As shown, the bubble-breaking unit 31 includes several parts such as a frame 311 and a bubble-breaking plate 312.

[0054] The frame 311 is roughly U-shaped, and several bubble-breaking plates 312 are arranged at intervals inside it. The bubble-breaking plates 312 divide the interior of the frame 311 into several first flow regions 313. The bubble-breaking plates 312 are configured to divide large bubbles into multiple small bubbles, thereby reducing bubble coalescence and improving gas-solid contact rate.

[0055] Furthermore, to effectively reduce the bubble diameter, prevent bubble re-aggregation, and promote gas-solid mixing for a more uniform particle distribution, in this embodiment, the bubble-breaking plate 312 is disposed at an angle inside the frame 311. The angled bubble-breaking plate 312 generates a rotating flow by changing the airflow direction, thereby breaking the bubbles using shear force.

[0056] Furthermore, to further prevent bubble re-coalition, in this embodiment, as... Figure 8 As shown, the bubble-breaking plates 312 at the same location of each two adjacent bubble-breaking layers 3 are in opposite directions, and the airflow presents a zigzag flow in the axial direction of the reactor body 1.

[0057] like Figure 7 As shown, the support plate 4 is arranged in a strip-like structure on the inner wall of the reactor body 1, 5-8 mm away from the bottom surface of the bubble breaker 3. This 5-8 mm gap provides a thermal expansion buffer space for the support plate 4, preventing the bubble breaker 3 from deforming due to expansion. Preferably, in this embodiment, as... Figure 1As shown, there are 3 sets of support plates 4, corresponding to the top 3 layers of bubble breakers 3. Figure 4 As shown, each set of support plates 4 includes several parts such as a support body 41 and a partition plate 42.

[0058] One end of the support body 41 is disposed on the inner wall of one side of the reactor body 1, and the other end extends to the inner wall of the opposite side of the reactor body 1 and connects with the inner wall of the opposite side. The support body 41 is configured to provide basic support for the bubble breaker 3.

[0059] Several baffles 42 are orthogonally arranged inside the support body 41. These baffles 42 divide the interior of the support body 41 into several second flow regions 43. The baffles 42 not only provide reinforced support for the bubble breaker 3, but also divide large bubbles, further enhancing the bubble breaking effect. At the same time, the extended baffles 42 further divide the fluidized bed into parallel sub-regions, suppressing lateral bubble aggregation and thus improving the stability of the reaction.

[0060] Furthermore, to ensure uniform distribution of support force, avoid localized stress concentration, reduce airflow disturbance, and maintain reaction stability, in this embodiment, the height of the support body 41 is equal to the height of the partition 42.

[0061] Furthermore, to prevent the reactor body 1 from generating enormous thermal stress inside the support plate 4 due to thermal expansion during the operation of the fluidized bed reactor, which could lead to cracking at the connection between the support plate 4 and the reactor body 1, bending deformation of the support plate 4 itself, or even collapse, in this embodiment, one end of the support body 41 is fixedly mounted on one side of the inner wall of the reactor body 1, and the other end extends to the opposite inner wall of the reactor body 1, and is movably connected to the opposite inner wall.

[0062] Specifically, such as Figures 5-6 As shown, multiple connecting seats 5 are fixedly installed on the inner wall of the reactor body 1. Each connecting seat 5 mainly consists of two opposing connecting plates 51. Each connecting plate 51 has a through-hole 52, and a connecting hole 411 is opened at the other end of the supporting body 41 corresponding to the through-hole 52. The end of the supporting body 41 with the connecting hole 411 is placed in the connecting seat 5, so that the connecting hole 411 corresponds to the through-hole 52. Then, double-ended bolts 6 are used to pass through the through-hole 52 and the connecting hole 411 in sequence, and finally, they are fixed with nuts 7, thereby realizing the movable connection between one end of the supporting body 41 and the reactor body 1.

[0063] like Figure 7As shown, when the reactor body 1 expands due to heat, the length direction of the elongated hole 52 provides axial freedom, and the support plate 4 can freely expand and contract in the length direction (along the direction of the elongated hole 52), releasing thermal stress and preventing the connection between the support plate 4 and the reactor body 1 from being torn or the support plate 4 itself from bending and deforming or even collapsing.

[0064] Furthermore, tolerances (dimensional errors) are unavoidable in the manufacturing, transportation, and on-site installation of large fluidized bed equipment, and the connection point between the connecting seat 5 and the support body 41 may not be perfectly aligned. The design of the elongated hole 52 provides a certain degree of adjustment leeway. When installing the support plate 4, the installer can move the position of the support body 41 within the length range of the elongated hole 52, making it easier to align with the connecting seat 5, thereby greatly simplifying the installation process and reducing the stringent precision requirements.

[0065] Meanwhile, during the operation of the fluidized bed reactor, the intense gas-solid flow inside will generate vibration. The design of the elongated hole 52 allows the support plate 4 to have slight relative movement in the direction and range defined by the elongated hole 52, so that the support plate 4 can better absorb and adapt to these vibrations or micro-deformations, and avoid transmitting excessive dynamic stress to the connecting seat 5.

[0066] Furthermore, in this embodiment, the length of the oblong hole 52 is 50-80 mm. Preferably, in this embodiment, the length of the oblong hole 52 is 50 mm.

[0067] Furthermore, in this embodiment, the support plate 4 is made of austenitic stainless steel.

[0068] In operation, gas enters the reactor body 1 through the bottom gas inlet channel 11, passing through the gas distribution plate 2 at a sufficiently high flow rate. After being evenly distributed by the gas distribution plate 2, the gas flows upward through the reactor body 1. Silicon powder enters the reactor body 1 through the powder inlet channel 12, where it is "lifted" by the upward-flowing gas, keeping it in a fluidized state. During the reaction, excess gas aggregates and forms bubbles. These bubbles are broken down by several layers of bubble breakers 3, forming smaller bubbles, increasing the gas-solid contact area and promoting the uniform distribution of the gas-solid two-phase flow, thereby improving reaction efficiency. The support plate 4 provides stable support for the bubble breakers 3, preventing them from collapsing and ensuring their efficient operation, thus guaranteeing the efficient and stable operation of the chemical reaction. Finally, the gaseous product trichlorosilane, along with unreacted hydrogen, silicon tetrachloride, and other possible byproduct gases, is discharged from the exhaust channel 13 at the top of the reactor body 1. The discharged mixed gas enters a subsequent separation and purification system to purify it into the desired trichlorosilane product, and the unreacted materials are recycled.

[0069] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A polycrystalline silicon cold hydrogenation fluidized bed reactor, characterized in that, include: The reactor body has a gas inlet channel, a powder inlet channel, and an exhaust channel. Inside the reactor body are a gas distribution plate, a bubble breaker, and a support plate. The gas distribution plate is located above the gas inlet channel, and the bubble breaker is located above the gas distribution plate. The support plate is located below the bubble breaker to support the bubble breaker and cut bubbles. The support plate includes: a support body, one end of which is disposed on the inner wall of one side of the reactor body, and the other end extending to and connecting to the inner wall of the opposite side of the reactor body; and a partition plate disposed on the support body.

2. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 1, characterized in that, The height of the supporting body is equal to the height of the partition.

3. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 1, characterized in that, One end of the support body is fixedly mounted on the inner wall of one side of the reactor body, and the other end extends to the inner wall of the opposite side of the reactor body and is movably connected to the inner wall of the opposite side.

4. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 3, characterized in that, Multiple connecting seats are fixedly installed on the inner wall of the reactor body. Each connecting seat has an elongated hole through it, and a connecting hole is opened at the other end of the supporting body corresponding to the elongated hole.

5. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 1, characterized in that, The support plate is 5-8 mm away from the bubble breaker.

6. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 1, characterized in that, The bubble breaker is mainly composed of multiple bubble breaking units arranged in layers along the inner wall of the reactor body. The shape of the bubble breaker is adapted to the inner wall of the reactor body, and the arrangement direction of each two adjacent bubble breaking units is perpendicular to each other.

7. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 6, characterized in that, The number of bubble breakers is multi-layered, and the number of support plates is 3 sets, corresponding to the top 3 layers of bubble breakers respectively.

8. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 7, characterized in that, The bubble-breaking unit includes: a frame, which is shaped like a square; and several bubble-breaking plates disposed on the frame.

9. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 8, characterized in that, The bubble-breaking plate is installed at an angle inside the frame.

10. The polycrystalline silicon cold hydrogenation fluidized bed reactor according to claim 9, characterized in that, The bubble-breaking plates at the same location in each of two adjacent bubble-breaking layers are oriented in opposite directions.

Images