Flow guide tube and single crystal furnace

Abstract

This application relates to the field of monocrystalline silicon manufacturing technology, and discloses a guide tube and a monocrystalline furnace. The guide tube includes: a guide tube body with an inner cavity, an inner wall and an outer wall forming an installation cavity, and an open end on the inner wall; a movable plate located in the installation cavity; and a driving assembly dynamically coupled to the movable plate. The driving assembly is used to drive the movable plate to extend from a first position through the open end into the inner cavity of the guide tube body to a second position or retract from the second position into the installation cavity back to the first position, thereby correspondingly reducing or increasing the inner diameter of the inner cavity of the guide tube body. This application reduces the inner diameter of the inner cavity of the guide tube body during the charging, heating of the molten material, temperature adjustment, and crystal pulling stages to prevent more impurities from precipitating from the crucible material and entering the silicon melt, which would further affect the quality of the monocrystalline silicon rod. The inner diameter of the inner cavity of the guide tube body is increased during the shoulder-forming stage, the shoulder-turning stage, the constant-diameter stage, and the finishing stage to ensure normal monocrystalline silicon pulling.

Description

Technical Field

[0001] This application relates to the field of monocrystalline silicon manufacturing technology, and in particular to a flow guide tube and a monocrystalline furnace. Background Technology

[0002] As the size of monocrystalline silicon wafers increases, existing guide tubes with fixed inner diameters need to have their inner diameter increased to ensure the normal pulling of monocrystalline silicon when pulling large-sized monocrystalline silicon rods.

[0003] Increasing the inner diameter of the guide tube will increase the heat loss from the surface of the silicon melt solution inside the crucible. At this time, it is necessary to increase the power of the heater during the charging, heating of the melt, temperature adjustment, and crystal pulling stages. This will cause the temperature of the crucible wall to rise, resulting in more impurities precipitating from the crucible material and entering the silicon melt, further affecting the quality of the single crystal silicon rod.

[0004] The information disclosed in the background section is only for enhancing the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] Based on this, a flow guide tube and a single crystal furnace are provided. The flow guide tube controls the position of the movable plate through a drive component, thereby controlling the inner diameter of the inner cavity of the flow guide tube body. The inner diameter of the inner cavity of the flow guide tube body can be reduced during the charging, heating of the molten material, temperature adjustment, and crystal pulling stages to avoid heat loss from the surface of the silicon solution. This eliminates the need to increase the heating power of the heater and prevents more impurities from precipitating from the crucible material and entering the silicon melt, which would further affect the quality of the single crystal silicon rod. The inner diameter of the inner cavity of the flow guide tube body can be increased during the shoulder-forming stage, shoulder-forming stage, constant diameter stage, and finishing stage to ensure normal pulling of single crystal silicon.

[0006] Therefore, in a first aspect, embodiments of this application provide a flow guide tube, comprising:

[0007] The guide tube body has an axially penetrating inner cavity. The guide tube body has an inner wall and an outer wall, which together form an installation cavity. The inner wall has an open end on the side facing the inner cavity of the guide tube body.

[0008] The movable plate is located in the mounting cavity;

[0009] A drive assembly is dynamically coupled to the movable plate. The drive assembly is used to drive the movable plate to extend from the opening end of the first position into the inner cavity of the guide tube body to the second position, or to retract from the second position into the mounting cavity to the first position, so as to correspondingly reduce or increase the inner diameter of the inner cavity of the guide tube body.

[0010] In one embodiment, the drive assembly is located in the mounting cavity.

[0011] In one embodiment, the drive assembly includes a drive member and a drive gear, the output end of the drive member is connected to the drive gear, the movable plate is provided with teeth on one side facing the drive gear, the teeth extend radially along the guide tube body, and the drive gear meshes with the teeth.

[0012] In one embodiment, the surface of the drive element is provided with a heat-insulating coating.

[0013] In one embodiment, the movable plate is arranged in a fan shape.

[0014] In one embodiment, the bottom of the movable plate is provided with a protrusion, and when the movable plate is retracted into the mounting cavity to the first position, the protrusion is located outside the mounting cavity and its bottom surface is flush with the bottom surface of the guide tube body.

[0015] In one embodiment, multiple movable plates and driving components are provided, and the multiple movable plates and driving components are arranged at intervals along the inner circumferential direction of the guide tube body.

[0016] In one embodiment, the guide tube body is provided with an inner wall and an outer wall, the inner wall and the outer wall surrounding to form the mounting cavity.

[0017] In one embodiment, a sliding assembly is provided between the movable plate and the mounting cavity. The sliding assembly includes a first sliding portion located at the bottom of the movable plate and a second sliding portion located at the bottom wall of the mounting cavity. Either the first sliding portion or the second sliding portion is a slider, and the other is a groove.

[0018] Secondly, embodiments of this application provide a single crystal furnace, including a flow guide tube as described in any of the above claims.

[0019] According to the embodiments of this application, the guide tube and single crystal furnace include a guide tube body, a movable plate, and a driving assembly. The guide tube body is provided with an axially penetrating inner cavity, and the guide tube body is provided with an inner wall and an outer wall, which surround and form an installation cavity. An open end is provided on the side of the inner wall facing the inner cavity of the guide tube body. The movable plate is located in the installation cavity. The driving assembly is dynamically coupled to the movable plate. The driving assembly is used to drive the movable plate to extend from the open end of the guide tube body from a first position to a second position or to retract from the second position to the installation cavity back to the first position, so as to correspondingly reduce or increase the inner diameter of the inner cavity of the guide tube body. The guide tube of this application controls the position of the movable plate through the drive component, thereby controlling the change of the inner diameter of the inner cavity of the guide tube body. The inner diameter of the inner cavity of the guide tube body can be reduced during the charging, heating of the molten material, temperature adjustment, and crystal pulling stages to avoid heat loss from the surface of the silicon melt. This eliminates the need to increase the heater power and prevents more impurities from precipitating from the crucible material and entering the silicon melt, which would further affect the quality of the single crystal silicon rod. The inner diameter of the inner cavity of the guide tube body can be increased during the shoulder forming stage, shoulder forming stage, constant diameter stage, and finishing stage to ensure normal pulling of single crystal silicon. Attached Figure Description

[0020] Figure 1 This illustration shows a schematic diagram of a movable plate in a second position according to an embodiment of this application.

[0021] Figure 2 This illustration shows a schematic diagram of a movable plate in a first position according to an embodiment of this application.

[0022] Figure 3 This illustration shows a schematic diagram of the structure of a flow guide provided in an embodiment of this application;

[0023] Figure 4 This illustration shows a structural schematic diagram of a driving component provided in an embodiment of this application;

[0024] Figure 5 This illustration shows a top view of a movable plate in a second position according to an embodiment of this application;

[0025] Figure 6 This illustration shows a top view of a movable plate in a first position according to an embodiment of this application;

[0026] Figure 7 This is a top view of an active panel provided in an embodiment of this application.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Guide tube body; 11. Mounting cavity; 12. Inner wall; 13. Outer wall; 2. Movable plate; 21. Tooth; 22. Protrusion; 31. Driving component; 32. Driving gear. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0030] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show the components related to this utility model and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0031] The structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0032] The orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "middle," "longitudinal," "transverse," "horizontal," "inner," "outer," "radial," and "circumferential" used in this specification are based on the orientations or positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] Inside the single-crystal furnace, the flow guide tube is located above the crucible. The flow guide tube maintains the temperature of the silicon solution by restricting the heat loss path within the crucible. As the diameter of the single-crystal silicon rod increases, the inner diameter of the flow guide tube's cavity also increases to ensure its smooth passage. This increases the space for heat to dissipate upwards through the flow guide tube, relatively increasing the surface area for heat conduction and convection. Heat is more easily dissipated into the surrounding environment through the flow guide tube, thus reducing the heat retention effect of the silicon solution. During the charging and heating stages, the heater power needs to be increased to accelerate silicon melting. This increased heater power intensifies thermal convection within the crucible, increasing scouring and causing more oxygen atoms to enter the silicon melt, reducing the quality of the single-crystal silicon. It also leads to increased heat loss. Furthermore, during the temperature control and crystal pulling stages, the intensified thermal convection within the crucible reduces the success rate of crystal pulling.

[0034] To solve the above problems, refer to Figures 1-4 , Figure 1 This diagram illustrates a structure of a movable plate in a second position according to an embodiment of this application. Figure 2 This diagram illustrates a structure of a movable plate in a first position according to an embodiment of this application. Figure 3 This diagram shows a schematic representation of a flow guide provided in an embodiment of this application. Figure 4 This diagram illustrates the structure of a driving component provided in an embodiment of this application.

[0035] This application provides a flow guide tube, comprising a flow guide tube body 1 with an axially penetrating inner cavity, the flow guide tube body 1 having an inner wall 12 and an outer wall 13, the inner wall 12 and the outer wall 13 forming an installation cavity 11, the inner wall 12 having an open end on the side facing the inner cavity of the flow guide tube body 1; a movable plate 2 located in the installation cavity 11; and a driving assembly dynamically coupled to the movable plate 2, the driving assembly being used to drive the movable plate 2 to extend from a first position through the open end into the inner cavity of the flow guide tube body 1 to a second position or retract from the second position into the installation cavity 11 to the first position, so as to correspondingly decrease or increase the inner diameter of the inner cavity of the flow guide tube body 1.

[0036] It is important to understand that the guide tube body 1 is cylindrical, meaning it has an axially penetrating inner cavity for the passage of pulled single-crystal silicon rods and for the passage of silicon material during feeding. The inner diameter of the guide tube body 1 gradually decreases from top to bottom to guide the airflow through the guide tube. The guide tube body 1 has an inner wall 12 and an outer wall 13, which together form an installation cavity 11. The inner wall 12 has an open end facing the guide tube body 1, meaning the installation cavity 11 communicates with the inner cavity of the guide tube body 1.

[0037] The movable plate 2 is located in the mounting cavity 11 and is slidably connected to the guide tube body 1. The movable plate 2 can be entirely located in the mounting cavity 11, or it can partially extend into the inner cavity of the guide tube body 1. To ensure smooth sliding of the movable plate 2 in the mounting cavity 11, a sliding assembly can be provided between the movable plate 2 and the bottom wall of the mounting cavity 11. The sliding assembly includes a first sliding part located at the bottom of the movable plate 2 and a second sliding part located on the bottom wall of the mounting cavity 11. Either the first sliding part or the second sliding part is a slider or a pulley, and the other is a groove.

[0038] The drive assembly is connected to the guide tube body 1 in a detachable manner to facilitate installation. The drive assembly can drive the movement of the movable plate 2. The drive assembly can drive the movable plate 2 from a first position extending from the open end into the inner cavity of the guide tube body 1 to a second position, and can also drive the movable plate 2 from the second position back into the mounting cavity 11 to the first position, thereby controlling the inner diameter of the guide tube body 1. The drive assembly can be a linear drive motor, a lead screw slide, a cylinder, or a hydraulic cylinder, etc., and this application is not limited to any particular type. The first position is when the movable plate 2 is retracted into the mounting cavity 11, at which point the inner diameter of the guide tube body 1 is at its maximum. The second position is when the movable plate extends out of the mounting cavity 11, at which point the inner diameter of the guide tube body 1 is at its minimum.

[0039] Reference Figures 1-6 , Figure 5 This illustration shows a top view of a movable plate in a second position according to an embodiment of this application. Figure 6 This diagram shows a top view of a movable plate in a first position according to an embodiment of this application. The guide tube is applied to a single-crystal furnace used in the single-crystal silicon pulling process. During the charging, melting, temperature control, and crystal pulling stages of the single-crystal silicon pulling process, the movable plate 2 is in a second position, and the inner diameter of the guide tube body 1 is at its minimum. During the shoulder-setting and shoulder-turning stages of the single-crystal silicon pulling process, the driving assembly drives the movable plate 2 to gradually retract from the inner cavity of the guide tube body 1 through the open end into the mounting cavity 11, and the inner diameter of the guide tube body 1 gradually increases. During the constant-diameter stage and the finishing stage of the single-crystal silicon pulling process, the movable plate 2 is in a first position, and the inner diameter of the guide tube body 1 is at its maximum.

[0040] During the charging, melting, temperature control, and crystal pulling stages, the movable plate 2 is in the second position, which minimizes the inner diameter of the guide tube body 1. This allows for heat preservation of the crucible without increasing the power of the heater, reducing costs while improving the quality of the single crystal silicon rod.

[0041] During the shoulder placement and shoulder rotation stages, the drive assembly drives the movable plate 2 to gradually retract from the opening end of the mounting cavity 11 back into the mounting cavity 11 of the guide tube body 1, causing the inner diameter of the guide tube body 1 to gradually increase.

[0042] During the constant diameter stage and the finishing stage, the movable plate 2 is in the first position. At this time, the inner diameter of the guide tube body 1 is at its maximum, so as to facilitate the normal pulling of the single crystal silicon.

[0043] This application controls the position of the movable plate 2 via a drive component, thereby controlling the inner diameter of the cavity at the bottom of the guide tube body 1. The movable plate 2 can be in the second position during the loading, heating of the molten material, temperature adjustment, and crystal pulling stages, minimizing the inner diameter of the guide tube body 1. This prevents heat loss from the silicon melt, eliminating the need for additional heater power and preventing more impurities from precipitating from the crucible material and entering the silicon melt, which would further affect the quality of the single-crystal silicon rod. Then, the movable plate 2 gradually retracts to the first position during the shoulder-forming stage, shoulder-turning stage, equal-diameter stage, and finishing stage, maximizing the inner diameter of the guide tube body 1 to ensure normal single-crystal silicon pulling.

[0044] In some optional embodiments, the opening end is located at the bottom of the inner cavity of the guide tube body 1, and the movable plate 2 is also located at the bottom of the inner cavity of the mounting cavity 11, so as to control the inner diameter of the bottom inner cavity of the guide tube body 1.

[0045] Reference Figures 1-4 and Figure 7 In some optional embodiments, the drive assembly is located within the mounting cavity 11. Compared to having the drive assembly outside the mounting cavity 11, this arrangement reduces heat radiation to the drive assembly and improves its lifespan.

[0046] In some optional embodiments, the drive assembly includes a drive member 31 and a drive gear 32. The output end of the drive member 31 is connected to the drive gear 32. The movable plate 2 is provided with a tooth 21 on the side facing the drive gear 32. The tooth 21 extends radially along the guide tube body 1, and the drive gear 32 meshes with the tooth 21.

[0047] The driving component 31 is a motor. The output end of the motor can rotate in both directions. This application does not limit the type of motor; the specific selection can be determined according to the actual situation. The driving gear 32 is connected to the output end of the driving component 31. The driving component 31 can make the driving gear 32 rotate. The movable plate 2 is provided with a tooth 21 on the side facing the driving gear 32. The tooth 21 can be located above, below, or to the side of the movable plate 2, depending on the installation. The tooth 21 extends radially along the guide tube body 1 and meshes with the driving gear 32. When the driving gear 32 rotates, the movable plate 2 moves.

[0048] During operation, the output end of the drive component 31 drives the drive gear 32 to rotate in the first direction. The drive gear 32 drives the movable plate 2 to move radially along the guide tube body 1, causing the movable plate 2 to extend from the mounting cavity 11 into the inner cavity of the guide tube body 1, thereby reducing the inner diameter of the guide tube body 1. The output end of the drive component 31 drives the drive gear 32 to rotate in the second direction, causing the drive gear 32 to move the movable plate 2 radially along the guide tube body 1, causing the movable plate 2 to extend back from the inner cavity of the guide tube body 1 into the mounting cavity 11, thereby increasing the inner diameter of the guide tube body 1. Either the first direction or the second direction is clockwise, and the other is counterclockwise.

[0049] Reference Figures 5-7 In some optional embodiments, the movable plate 2 is arranged in a fan shape. The movable plate 2 can be circular, elongated, or triangular, and this application is not limited thereto. However, when multiple movable plates 2 are arranged at intervals along the circumference of the guide tube body 1, the fan shape of the movable plate 2 can reduce the inner diameter of the guide tube body 1 with the largest area compared to other shapes, thereby improving the heat preservation effect on the crucible.

[0050] In some optional embodiments, the surface of the drive component 31 is provided with a heat-insulating coating. The heat-insulating coating may be a ceramic-based coating, a metal-based coating, a metal-ceramic composite coating, a high-temperature resistant inorganic coating, or a composite coating system. This application does not impose any limitations. The heat-insulating coating can reduce the damage of high temperature to the drive component 31 and improve the service life of the drive component 31.

[0051] Reference Figures 1-3 In some optional embodiments, the bottom of the movable plate 2 is provided with a protrusion 22. When the movable plate 2 is retracted into the mounting cavity 11 to the first position, the protrusion 22 is located outside the mounting cavity 11 and its bottom surface is flush with the bottom surface of the guide tube body 1. The protrusion 22 can prevent the distance (liquid port distance) between the bottom of the guide tube body 1 and the liquid in the crucible from changing after the movable plate 2 is added. This is because: if the liquid port distance changes, it will affect the process control of single crystal growth. At present, the liquid port distance is used as an important basis for crystal growth window and safety distance in the crystal growth process, and the liquid port distance can only be measured at the middle position of the inner cavity. If the detected liquid port distance changes or the detection position is far away, it will cause the system to make a judgment error, which will lead to the crucible position rising rapidly. Once the crucible position rises rapidly, the silicon liquid in the crucible will come into contact with the movable plate, causing crystallization, silicon overflow, and even, in severe cases, furnace explosion, causing personal injury or death. Because when the movable plate 2 is in the first position, the bottom surface of the protrusion 22 of the movable plate 2 is flush with the bottom surface of the guide tube body 1, which can ensure that the measurement position and measurement structure of the liquid outlet distance do not change during the equal diameter stage, thus not affecting the existing process control of single crystal growth.

[0052] In some optional embodiments, multiple movable plates 2 and driving components are respectively provided, and the multiple movable plates 2 and driving components are arranged at intervals along the circumferential direction of the inner cavity of the guide tube body 1. Each movable plate 2 corresponds to one driving component. The arrangement of multiple movable plates 2 and driving components allows multiple driving components to drive multiple movable plates 2 to move simultaneously, or to drive only some of the movable plates 2 to move; this application does not impose any limitations. The arrangement of multiple driving components and multiple movable plates 2 can improve the control of the inner diameter of the guide tube body 1.

[0053] Reference Figure 3 In some optional embodiments, the guide tube body 1 is provided with an inner wall 12 and an outer wall 13, which together form an installation cavity 11. The inner wall 12 and the outer wall 13 can be fixed by welding, snap-fitting, or bolts, etc., which is not limited in this application. During installation, the drive assembly and the movable plate 2 are first installed in the outer wall 13 or outside the inner wall 12, and then the inner wall 12 and the outer wall 13 are installed.

[0054] In some optional embodiments, the inner wall 12 is provided with a first engaging portion, and the outer wall 13 is provided with a second engaging portion, which engage with each other. Either the first engaging portion or the second engaging portion is a groove, and the other is a protrusion. The provision of the first engaging portion and the second engaging portion facilitates the installation and disassembly of the inner wall 12 and the outer wall 13.

[0055] Reference Figures 1-7 This application also includes a single crystal furnace, which includes the guide tube described in any of the above claims. The guide tube includes a guide tube body 1, a movable plate 2, and a drive assembly. The guide tube body 1 is provided with an inner cavity for loading materials, and a mounting cavity 11 is provided on the side wall of the guide tube body 1. The mounting cavity 11 forms an open end on the side facing the inner cavity of the guide tube body 1. The movable plate 2 is located in the mounting cavity 11. The drive assembly is dynamically coupled to the movable plate 2, and the drive assembly is used to drive the movable plate 2 to extend from the open end into the inner cavity of the guide tube body 1 or retract into the mounting cavity 11, so as to control the inner diameter of the inner cavity of the guide tube body 1.

[0056] In the crystal pulling process of monocrystalline silicon, during the charging stage, melting stage, temperature control stage, and crystal pulling stage, the movable plate 2 is in the second stage, and the inner diameter of the inner cavity of the guide tube body 1 is at its minimum. This allows for crucible insulation without increasing heater power, reducing costs while improving the quality of the monocrystalline silicon rod. During the shoulder-setting and shoulder-turning stages, the drive assembly drives the movable plate 2 from the opening end of the mounting cavity 11 back into the mounting cavity 11 of the guide tube body 1, causing the inner diameter of the guide tube body 1 to gradually increase. During the constant diameter stage and the finishing stage, the movable plate 2 is in the first position, at which point the inner diameter of the guide tube body 1 is at its maximum, facilitating the normal pulling of the monocrystalline silicon.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A flow guide tube, characterized in that, include: The guide tube body (1) is provided with an axially penetrating inner cavity. The guide tube body (1) is provided with an inner wall (12) and an outer wall (13). The inner wall (12) and the outer wall (13) surround and form an installation cavity (11). The inner wall (12) has an open end on the side facing the inner cavity of the guide tube body (1). The movable plate (2) is located in the mounting cavity (11); A drive assembly is dynamically coupled to the movable plate (2). The drive assembly is used to drive the movable plate (2) to extend from the opening end of the first position into the inner cavity of the guide tube body (1) to the second position or to retract from the second position into the mounting cavity (11) to the first position, so as to correspondingly reduce or increase the inner diameter of the inner cavity of the guide tube body (1).

2. The guide tube according to claim 1, characterized in that, The drive assembly is located in the mounting cavity.

3. The guide tube according to claim 2, characterized in that, The drive assembly includes a drive member (31) and a drive gear (32). The output end of the drive member (31) is connected to the drive gear (32). The movable plate (2) is provided with a tooth (21) on the side facing the drive gear (32). The tooth (21) extends radially along the guide tube body (1). The drive gear (32) meshes with the tooth (21).

4. The guide tube according to claim 3, characterized in that, The surface of the drive component (31) is provided with a heat-insulating coating.

5. The guide tube according to claim 1, characterized in that, The movable plate (2) is arranged in a fan shape.

6. The guide tube according to claim 1, characterized in that, The opening end is located at the bottom of the inner cavity of the guide tube body (1).

7. The guide tube according to claim 6, characterized in that, The bottom of the movable plate (2) is provided with a protrusion (22). When the movable plate (2) is retracted to the first position in the mounting cavity (11), the protrusion (22) is located outside the mounting cavity (11) and its bottom surface is flush with the bottom surface of the guide tube body (1).

8. The guide tube according to claim 1, characterized in that, Multiple movable plates (2) and multiple driving components are provided, and the multiple movable plates (2) and multiple driving components are arranged at intervals along the inner cavity of the guide tube body (1).

9. The guide tube according to claim 1, characterized in that, A sliding assembly is provided between the movable plate (2) and the mounting cavity (11). The sliding assembly includes a first sliding part located at the bottom of the movable plate (2) and a second sliding part located at the bottom wall of the mounting cavity (11). Either the first sliding part or the second sliding part is a slider, and the other is a groove.

10. A single crystal furnace, characterized in that, Includes the flow guide tube as described in any one of claims 1-9.

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