Polycrystalline silicon reduction furnace
By setting a ceramic layer on the inner surface of the exhaust gas ring pipe of the polycrystalline silicon reduction furnace, the problem of flash explosion during the cleaning process was solved, a safe cleaning process was achieved, and damage to personnel and equipment was avoided.
Patent Information
- Application Number
- CN202423304343.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing polysilicon reduction furnaces are prone to flash explosions during the cleaning of the exhaust gas ring pipe, causing damage to personnel and equipment.
A ceramic layer, especially an alumina ceramic layer, is placed on the inner surface of the exhaust gas ring pipe to improve surface smoothness and reduce silica powder adhesion, thereby avoiding blockage.
It effectively reduces the risk of silicon powder clogging the exhaust gas ring pipe, eliminates the need for cleaning with iron rods, and avoids flash explosions and equipment damage.
Smart Images
Figure CN223620152U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of polycrystalline silicon production technology, and in particular to a polycrystalline silicon reduction furnace. Background Technology
[0002] Most domestic polysilicon manufacturers use the Siemens modified process, the main equipment of which is a reduction furnace. The working principle of the reduction furnace is to react a mixture of trichlorosilane and hydrogen to generate polysilicon, which is then deposited on a silicon core. The final product is polysilicon deposited on the silicon core.
[0003] In related technologies, the reduction furnace includes a main body and a tail gas ring pipe, with the tail gas ring pipe connected to the chassis of the main body. The tail gas generated in the reduction furnace is discharged through the tail gas ring pipe. When silicon powder in the tail gas accumulates on the inner surface of the tail gas ring pipe, causing blockage, it can be cleaned by poking the tail gas ring pipe with an iron rod.
[0004] However, cleaning the exhaust gas ring pipe by poking it with an iron rod can easily lead to a flash explosion, causing damage to personnel and equipment. Utility Model Content
[0005] This utility model provides a polycrystalline silicon reduction furnace to solve the problem that cleaning the tail gas ring pipe by poking it with an iron rod can easily lead to flash explosions, causing damage to personnel and equipment.
[0006] This utility model provides a polysilicon reduction furnace, including a main body and a tail gas ring pipe;
[0007] The main body includes a furnace cylinder and a chassis, the chassis being disposed at the bottom of the furnace cylinder, and the chassis and the furnace cylinder forming a reaction chamber;
[0008] The exhaust gas ring pipe includes a pipe body and a ceramic layer. The pipe body is connected to the chassis, and the ceramic layer is connected to the inner surface of the pipe body.
[0009] In one possible implementation, the tube body includes a first tube and a second tube, with the first tube sleeved on the outside of the second tube, and the ceramic layer connected to the inner surface of the second tube.
[0010] In one possible implementation, the ceramic layer is an alumina ceramic layer.
[0011] In one possible implementation, the system further includes a plurality of feed nozzles connected to the chassis, the plurality of feed nozzles being spaced apart along the circumferential direction of the chassis.
[0012] In one possible implementation, the chassis is provided with a plurality of electrode holders, which are arranged in multiple rings, with the plurality of electrode holders on each ring spaced apart in the circumferential direction of the chassis.
[0013] The plurality of feed nozzles are disposed between the plurality of electrode seats on two adjacent rings.
[0014] In one possible implementation, the feed nozzle has a main channel and a plurality of branch passages, the plurality of branch passages being connected to the main channel and spaced apart along the extension direction of the main channel, the branch passages being parallel to each other, and the main channel and the plurality of branch passages being connected to the reaction chamber respectively.
[0015] In one possible implementation, the branch section includes two branch channels located in the same plane and symmetrically arranged with respect to the axis of the main channel.
[0016] In one possible implementation, each of the branch channels is spaced apart from each of the electrode seats in the circumferential direction of the chassis.
[0017] In one possible implementation, the branch channel is an arc-shaped channel, and the angle between the outlet direction of the branch channel and the extension direction of the main channel is greater than or equal to 30° and less than or equal to 60°.
[0018] In one possible implementation, the difference between the outer diameter of the feed nozzle and the inner diameter of the feed nozzle is greater than or equal to 30 mm and less than or equal to 45 mm.
[0019] This utility model provides a polycrystalline silicon reduction furnace, in which a ceramic layer is connected to the inner surface of the exhaust gas ring pipe. The ceramic layer has a smooth surface, which can effectively reduce silicon powder adhesion, so that silicon powder will not clog the exhaust gas ring pipe. This eliminates the need to clean the exhaust gas ring pipe with an iron rod, thereby avoiding damage to personnel and equipment. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 A cross-sectional schematic diagram of a polycrystalline silicon reduction furnace provided for an embodiment of this utility model;
[0022] Figure 2 A top view of the chassis, electrode holder, exhaust gas ring pipe and feed nozzle connected according to an embodiment of the present utility model;
[0023] Figure 3A cross-sectional schematic diagram of the exhaust gas ring pipe provided in an embodiment of this utility model;
[0024] Figure 4 for Figure 1 Enlarged diagram of point A in the middle.
[0025] Explanation of reference numerals in the attached figures:
[0026] 10 - Furnace cylinder; 101 - Reaction chamber;
[0027] 20 - Chassis; 21 - Electrode holder;
[0028] 22 - Silicon core; 30 - Exhaust gas ring pipe;
[0029] 301 - First Channel; 302 - Second Channel;
[0030] 31 - First tube; 32 - Second tube;
[0031] 33 - Ceramic layer; 40 - Feed nozzle;
[0032] 41-Main passage; 42-Branch passage;
[0033] 421 - Branch channel; 50 - Feed pipe. Detailed Implementation
[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0035] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0036] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "fixation," 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 connection that allows communication between the components; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0037] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0038] In the above description, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0039] As described in the background section, cleaning the exhaust gas ring pipe by poking it with an iron rod can easily lead to a flash explosion, causing injury to personnel and equipment. The inventors discovered that this problem occurs because silicon powder in the exhaust gas accumulates on the inner surface of the exhaust gas ring pipe, causing blockage. When cleaning by poking the exhaust gas ring pipe with an iron rod, the collision between the rod and the pipe generates sparks. Since residual hydrogen gas may remain in the exhaust gas ring pipe, this can easily lead to a flash explosion, causing injury to personnel and equipment.
[0040] To address the aforementioned issues, this utility model provides a polycrystalline silicon reduction furnace. By setting a ceramic layer on the inner surface of the exhaust gas ring tube, the smooth surface of the ceramic layer effectively reduces silicon powder adhesion, thus preventing silicon powder from clogging the exhaust gas ring tube. This eliminates the need to clean the exhaust gas ring tube with an iron rod, thereby avoiding damage to personnel and equipment.
[0041] The polysilicon reduction furnace provided in this utility model embodiment will be described in detail below with reference to specific embodiments.
[0042] This embodiment of the invention provides a polycrystalline silicon reduction furnace. The height direction of the polycrystalline silicon reduction furnace is the Z-axis direction.
[0043] The polysilicon reduction furnace includes the main body and the exhaust gas ring pipe 30.
[0044] See Figure 1 As shown, the main body may include a furnace cylinder 10 and a chassis 20.
[0045] The top of the furnace cylinder 10 is on the side with the +Z axis, and the bottom of the furnace cylinder 10 is on the side with the -Z axis.
[0046] The chassis 20 is located at the bottom of the furnace cylinder 10. The chassis 20 is sealed to the furnace cylinder 10.
[0047] The chassis 20 and the furnace cylinder 10 can form a reaction chamber 101. Inside the reaction chamber 101, a mixture of trichlorosilane and hydrogen reacts, and the exhaust gas after the reaction may include trichlorosilane, hydrogen, tetrachlorosilane, and silicon powder, etc.
[0048] In some examples, the chassis 20 is arranged in a circular shape.
[0049] Figure 1 The image shows a portion of the electrode holder 21, silicon core 22, and feed nozzle 40.
[0050] See Figure 1 and Figure 2 As shown in the figure, the chassis 20 is provided with multiple electrode holders 21 and multiple silicon cores 22.
[0051] Each electrode holder 21 can be welded to the chassis 20. Multiple electrode holders 21 are arranged in multiple rings. The multiple electrode holders 21 on each ring are spaced apart in the circumferential direction of the chassis 20. For example, the multiple electrode holders 21 can be arranged in four rings.
[0052] Each electrode holder 21 is equipped with a silicon core 22. The electrode holder 21 can be connected to a power supply system. When the electrode holder 21 is powered on, it can heat the silicon core 22. When the surface temperature of the silicon core 22 reaches the reaction regulation of trichlorosilane and hydrogen, the mixed gas begins to undergo a reduction reaction.
[0053] In some examples, each silicon core 22 may extend along the height direction of the polysilicon reduction furnace.
[0054] See Figure 1 and Figure 3As shown, the exhaust gas ring pipe 30 may include a pipe body and a ceramic layer 33. The pipe body is connected to the chassis 20, and the ceramic layer 33 is connected to the inner surface of the pipe body. This configuration, with the ceramic layer 33 connected to the inner surface of the pipe body of the exhaust gas ring pipe 30, and the smooth surface of the ceramic layer 33, effectively reduces silicon powder adhesion, preventing silicon powder from clogging the exhaust gas ring pipe 30. This eliminates the need for cleaning the exhaust gas ring pipe with an iron rod, thereby avoiding injury to personnel and equipment.
[0055] In one possible implementation, see Figure 3 As shown, the tube body includes a first tube 31 and a second tube 32. The first tube 31 is fitted onto the outside of the second tube 32, and the ceramic layer 33 is connected to the inner surface of the second tube 32.
[0056] The first pipe 31 and the second pipe 32 can be welded to the chassis 20 respectively.
[0057] A first channel 301 is provided between the first tube 31 and the second tube 32. The coolant in the polysilicon reduction furnace can flow out through the first channel 301.
[0058] The second tube 32 has a second channel 302. The exhaust gas in the polysilicon reduction furnace can be discharged through the second channel 302.
[0059] In one possible implementation, the ceramic layer 33 may be an alumina ceramic layer. In other embodiments, the ceramic layer 33 may be formed by mixing alumina ceramic with other materials. In the ceramic layer 33, the mass percentage of alumina ceramic may be greater than or equal to 75% and less than or equal to 85%.
[0060] It should be noted that alumina ceramics have high hardness, good wear resistance, dense and smooth surface, and can withstand high temperatures of 1400℃.
[0061] In some examples, both the first tube 31 and the second tube 32 are circular tubes. The first tube 31 and the second tube 32 can be coaxially arranged. The thickness of the alumina ceramic layer in the radial direction of the second tube 32 can be greater than or equal to 1 μm and less than or equal to 10 μm. When the thickness of the alumina ceramic layer in the radial direction of the second tube 32 is less than 1 μm, it increases manufacturing difficulty. When the thickness of the alumina ceramic layer in the radial direction of the second tube 32 is greater than 10 μm, it increases the production cost of the polycrystalline silicon reduction furnace. By ensuring that the thickness of the alumina ceramic layer in the radial direction of the second tube 32 is greater than or equal to 1 μm and less than or equal to 10 μm, manufacturing difficulty can be reduced, and the production cost of the polycrystalline silicon reduction furnace can also be reduced.
[0062] In one possible implementation, the alumina ceramic layer is fabricated as follows: 1) The inner surface of the second tube 32 of the exhaust gas ring pipe 30 is cleaned to remove silica powder. 2) Aluminum trichloride is dissolved in sodium hydroxide solution to form a sol. 3) The sol is introduced into the second tube 32 of the exhaust gas ring pipe 30 and sealed within the second tube 32 until the sol coats the inner surface of the second tube 32. Then, the sol sealed within the second tube 32 is released. 4) After the sol on the inner surface of the second tube 32 dries, the exhaust gas ring pipe 30 coated with the sol is heated to 800°C or higher to form the alumina ceramic layer.
[0063] In one possible implementation, see Figure 1 and Figure 2 As shown, the polysilicon reduction furnace also includes multiple feed nozzles 40. Each feed nozzle 40 is connected to a feed pipe 50.
[0064] The feed gas can be a mixture of trichlorosilane and hydrogen. The feed gas can enter the reaction chamber 101 of the polycrystalline silicon reduction furnace through the feed nozzle 40.
[0065] Multiple feed nozzles 40 can be connected to the chassis 20, and the multiple feed nozzles 40 are spaced apart along the circumference of the chassis 20. This arrangement can ensure that the feed gas distribution in the polysilicon reduction furnace is uniform.
[0066] Multiple feed nozzles 40 can be arranged between multiple electrode seats 21 on two adjacent rings. It can be understood that multiple feed nozzles 40 can be arranged between multiple electrode seats 21 on one ring and multiple electrode seats 21 on another ring.
[0067] In one possible implementation, see Figure 1 and Figure 4 As shown, the feed nozzle 40 has a main channel 41 and multiple branch sections 42, which are connected to the main channel 41. The main channel 41 and the multiple branch sections 42 are respectively connected to the reaction chamber 101. This configuration can increase the flow rate of the feed gas entering the polycrystalline silicon reduction furnace.
[0068] The main channel 41 can be cylindrical. The main channel 41 can extend along the height direction of the polysilicon reduction furnace.
[0069] Multiple branch passages 42 are spaced apart along the extension direction of the main channel 41, and each branch passage 42 is parallel to the others. This arrangement can increase the amount of feed gas entering the polysilicon reduction furnace.
[0070] In one possible implementation, see Figure 4As shown, the branch passage 42 includes two branch channels 421, which are located in the same plane and are symmetrically arranged with respect to the axis of the main channel 41. This arrangement, with the two branch channels 421 symmetrically arranged, ensures that the feed gas is evenly distributed when it enters the reaction chamber 101, which helps to reduce uneven flow and turbulence.
[0071] In one possible implementation, each branch channel 421 is spaced apart from each electrode holder 21 in the circumferential direction of the chassis 20. This arrangement, with each branch channel 421 spaced apart from each silicon core 22 in the circumferential direction of the chassis 20, ensures that the silicon core 22 is not in the air outlet direction of the branch channel 421. This reduces the force exerted by the airflow in the branch channel 421 on the silicon core 22, ensuring the stability of the silicon core 22 and preventing vibration of the silicon core 22 caused by the feed gas, which could lead to inverted rods.
[0072] In one possible implementation, the branch channel 421 is an arc-shaped channel, and the angle between the outlet direction of the branch channel 421 and the extension direction of the main channel 41 is greater than or equal to 30° and less than or equal to 60°. This arrangement allows the feed gas in the branch channel 421 to diffuse around the main channel 41, which is beneficial for the uniform distribution of feed gas in the polysilicon reduction furnace.
[0073] The arc-shaped channel extends toward the top of the furnace cylinder 10. The outlet direction of the branch channel 421 can be tangent to the extension direction of the arc-shaped channel.
[0074] In some examples, the exit direction of branch channel 421 can be the +X axis direction. The angle between the exit direction of branch channel 421 and the extension direction of main channel 41 can be the angle between the +X axis direction and the +Z axis direction.
[0075] In one possible implementation, the feed nozzle 40 may be cylindrical.
[0076] The inner diameter R2 of the feed nozzle 40 is greater than or equal to 5 mm and less than or equal to 10 mm. The outer diameter R1 of the feed nozzle 40 is greater than or equal to 40 mm and less than or equal to 50 mm.
[0077] The difference between the outer diameter R1 and the inner diameter R2 of the feed nozzle is greater than or equal to 30 mm and less than or equal to 45 mm. When the difference is less than 30 mm, the length of the branch channel 421 is too short, which will cause the airflow in the branch channel 421 to exert a force on the silicon core 22, making the silicon core 22 unstable. When the difference is greater than 45 mm, the length of the branch channel 421 is too long, which will increase the production cost of the polysilicon reduction furnace. When the difference is greater than or equal to 30 mm and less than or equal to 45 mm, the force of the airflow in the branch channel 421 on the silicon core 22 can be reduced, improving the stability of the silicon core 22, and at the same time reducing the production cost of the polysilicon reduction furnace.
[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A polycrystalline silicon reduction furnace, characterized in that, Includes the main body and the exhaust ring pipe (30); The main body includes a furnace cylinder (10) and a chassis (20), the chassis (20) is disposed at the bottom of the furnace cylinder (10), and the chassis (20) and the furnace cylinder (10) form a reaction chamber (101); The exhaust gas ring pipe (30) includes a pipe body and a ceramic layer (33). The pipe body is connected to the chassis (20), and the ceramic layer (33) is connected to the inner surface of the pipe body.
2. The polycrystalline silicon reduction furnace according to claim 1, characterized in that, The tube body includes a first tube (31) and a second tube (32), the first tube (31) is sleeved on the outside of the second tube (32), and the ceramic layer (33) is connected to the inner surface of the second tube (32).
3. The polycrystalline silicon reduction furnace according to claim 2, characterized in that, The ceramic layer (33) is an alumina ceramic layer (33).
4. The polycrystalline silicon reduction furnace according to any one of claims 1-3, characterized in that, It also includes multiple feed nozzles (40), which are connected to the chassis (20) and are spaced apart along the circumferential direction of the chassis (20).
5. The polycrystalline silicon reduction furnace according to claim 4, characterized in that, The chassis (20) is provided with a plurality of electrode seats (21), which are arranged in multiple rings. In the circumferential direction of the chassis (20), the plurality of electrode seats (21) on each ring are spaced apart. Multiple feed nozzles (40) are disposed between multiple electrode seats (21) on two adjacent rings.
6. The polycrystalline silicon reduction furnace according to claim 5, characterized in that, The feed nozzle (40) has a main channel (41) and a plurality of branch passages (42). The plurality of branch passages (42) are connected to the main channel (41). The plurality of branch passages (42) are spaced apart along the extension direction of the main channel (41). Each branch passage (42) is parallel to each other. The main channel (41) and the plurality of branch passages (42) are respectively connected to the reaction chamber (101).
7. The polycrystalline silicon reduction furnace according to claim 6, characterized in that, The branch passage (42) includes two branch channels (421), which are located in the same plane and are symmetrically arranged with respect to the axis of the main channel (41).
8. The polycrystalline silicon reduction furnace according to claim 7, characterized in that, In the circumferential direction of the chassis (20), each of the branch channels (421) is spaced apart from each of the electrode seats (21).
9. The polycrystalline silicon reduction furnace according to claim 7, characterized in that, The branch channel (421) is an arc-shaped channel, and the angle between the outlet direction of the branch channel (421) and the extension direction of the main channel (41) is greater than or equal to 30° and less than or equal to 60°.
10. The polycrystalline silicon reduction furnace according to claim 4, characterized in that, The difference between the outer diameter and the inner diameter of the feed nozzle (40) is greater than or equal to 30 mm and less than or equal to 45 mm.