A gas guide cylinder for a single crystal furnace and a single crystal furnace

Abstract

The utility model belongs to the single crystal furnace technical field provides a single crystal furnace with air guide cylinder and single crystal furnace, its air guide cylinder is located at the exhaust port of single crystal furnace furnace bottom, and it includes: first cylinder and second cylinder, they are connected to form first runner, second runner and third runner which communicate in turn, wherein, first runner entrance faces single crystal furnace furnace, its inner diameter gradually reduces along the airflow flow direction, third runner outlet faces single crystal furnace furnace outside, its inner diameter gradually increases along the airflow flow direction. The single crystal furnace includes the air guide cylinder. Compared with prior art, the utility model discloses through the first runner of inner diameter tapering, the second runner of constant inner diameter and the third runner of inner diameter gradually expanding, can quickly discharge the impurity such as oxide in the furnace, and each runner is not easy to accumulate dust, reduces the possibility of causing the blockage after long -time operation, can reduce the heat loss in the furnace simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of single crystal furnace technology, specifically to a gas guide tube for a single crystal furnace and a single crystal furnace. Background Technology

[0002] The Czochralski method is a commonly used method for pulling single-crystal silicon rods. This method involves placing polycrystalline silicon into a quartz crucible in a single-crystal furnace, heating and melting the polycrystalline silicon using a graphite heater, and then completing the pulling of the single-crystal silicon rod through processes such as temperature adjustment, crystal pulling, shoulder formation, shoulder rotation, equal diameter setting, tailing, and furnace shutdown.

[0003] During the single crystal pulling process, in order to achieve inert gas atmosphere protection and maintain a vacuum state, the single crystal furnace needs to continuously blow argon gas to remove oxides and dust impurities generated inside the furnace, as well as the latent heat of crystallization generated when liquid silicon solidifies into solid silicon during crystal growth. To prevent these oxides and dust from corroding the furnace bottom insulation, a gas guide is usually installed at the exhaust port of the single crystal furnace bottom to discharge volatile oxides and other impurities inside the furnace, thereby preventing crystal rod oxidation and ensuring quality.

[0004] Currently, the gas guide tube is usually a straight cylindrical structure made of graphite. While expelling oxides, heat in the hot zone is also lost. On the one hand, the larger the diameter of the gas guide tube, the faster the exhaust, the faster the oxides and other impurities in the furnace are removed, and the better the quality of the crystal rods. However, the heat loss is also greater, requiring an increase in heater power to maintain a stable furnace temperature, which increases the overall power consumption of the hot zone. On the other hand, reducing the diameter of the gas guide tube can reduce heat loss and help reduce the input power of the heater, achieving a power saving effect. However, the exhaust of oxides is affected, and they are prone to accumulate at the gas guide tube, causing blockage after long-term operation.

[0005] Therefore, there is an urgent need to develop a new type of gas guide tube to simultaneously meet the requirements of rapid exhaust of impurities such as oxides in the furnace and minimal heat loss from the furnace. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model provides a gas guide tube and a single crystal furnace for a single crystal furnace, which can accelerate the discharge of impurities such as oxides from the furnace while reducing heat loss from the furnace.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A gas guide tube for a single crystal furnace, disposed at the exhaust port at the bottom of the single crystal furnace, the gas guide tube comprising:

[0009] The first cylinder and the second cylinder are connected to each other to form a first flow channel, a second flow channel and a third flow channel that are connected in sequence;

[0010] The first flow channel inlet faces the inside of the single crystal furnace, and its inner diameter gradually decreases along the airflow direction. The third flow channel outlet faces the outside of the single crystal furnace, and its inner diameter gradually increases along the airflow direction.

[0011] In one embodiment disclosed in this application, the first cylinder has a first conical section and a first straight section. The internal channel of the first conical section is the first flow channel. The large end of the first conical section is used as the inlet of the first flow channel, and the small end is connected to the first straight section.

[0012] The second cylinder has a second conical section and a second straight section. The internal channel of the second conical section is the third flow channel. The large end of the second conical section is used as the outlet of the third flow channel, and the small end is connected to the second straight section.

[0013] The outer diameter of the second straight cylindrical section is equal to the inner diameter of the first straight cylindrical section, and the second straight cylindrical section is sealed to the first straight cylindrical section by complete insertion to form the second flow channel.

[0014] In one embodiment disclosed in this application, the inner diameter of the large end of the first conical section is equal to the inner diameter of the large end of the second conical section.

[0015] In one embodiment disclosed in this application, an annular drainage cone surface is provided on the inner side of the end of the second straight cylinder portion away from the second conical cylinder portion;

[0016] The large-diameter portion of the drainage cone extends to the inner diameter opening corresponding to the small end of the first cone.

[0017] In one embodiment disclosed in this application, a guide strip extending spirally along the airflow direction is provided on the inner circumferential sidewall of the second straight cylindrical portion;

[0018] The guide strip protrudes from the inner circumference of the second straight cylinder to guide the airflow.

[0019] In one embodiment disclosed in this application, the inner circumferential wall of the first straight cylindrical portion is provided with an internal thread;

[0020] The outer circumferential wall of the second straight cylindrical section is provided with external threads;

[0021] The second straight section is threadedly connected to the first straight section to achieve complete insertion and sealing.

[0022] In one embodiment disclosed in this application, both the first cylinder and the second cylinder are made of carbon-carbon composite material.

[0023] A single crystal furnace, comprising a gas guide tube for a single crystal furnace as described in any one of the above.

[0024] Compared with the prior art, the beneficial effects of this utility model are:

[0025] 1. By using the first flow channel with a gradually narrowing inner diameter, the second flow channel with a constant inner diameter, and the third flow channel with a gradually expanding inner diameter, it is possible to quickly discharge oxides and other impurities from the furnace. Moreover, each flow channel is less prone to ash accumulation, reducing the possibility of blockage after long-term operation, and at the same time, it can reduce heat loss from the furnace.

[0026] 2. The inner diameter of the large end of the first cone section is equal to that of the large end of the second cone section, which can avoid causing turbulent airflow in the furnace, help stabilize the gas pressure in the furnace, effectively reduce heat loss, and at the same time not affect the rapid discharge of oxides and other impurities in the furnace.

[0027] 3. The raised guide strips can guide the airflow in a spiral manner, increase its flow rate, accelerate the discharge of oxides and other impurities in the furnace, quickly reduce the oxygen content in the furnace, and improve production quality. At the same time, the spiral airflow has strong fluidity and a certain vibration capability, which will disturb oxides and other impurities and prevent oxides and other impurities from accumulating or adhering in the flow channel and affecting exhaust efficiency.

[0028] 4. The second straight section and the first straight section are connected by threads to form a sleeve structure. Adjusting the screwing depth can change the height (length) of the gas guide tube, thus making it suitable for the thermal field thickness of different single crystal furnace bottoms and improving the applicability of this gas guide tube. Attached Figure Description

[0029] 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.

[0030] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0031] Figure 2 This is a schematic diagram of the three-dimensional structure of the first cylinder;

[0032] Figure 3 This is a schematic diagram of the three-dimensional structure of the second cylinder;

[0033] Figure 4 This is a schematic diagram of the cross-sectional structure of the second cylinder. Detailed Implementation

[0034] 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.

[0035] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 a limitation of this utility model.

[0036] Furthermore, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," 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 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. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0038] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this invention.

[0040] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0041] See Figures 1-4 As shown, on one hand, this utility model provides a gas guide tube for a single crystal furnace, which is located at the exhaust port at the bottom of the single crystal furnace. The gas guide tube includes:

[0042] The first cylinder 10 and the second cylinder 20 are connected to each other to form a first flow channel, a second flow channel and a third flow channel that are connected in sequence;

[0043] The first flow channel inlet faces the inside of the single crystal furnace, and its inner diameter gradually decreases along the airflow direction. The third flow channel outlet faces the outside of the single crystal furnace, and its inner diameter gradually increases along the airflow direction.

[0044] Specifically, the first cylindrical body 10 has a first conical section 11 and a first straight section 12. The internal channel of the first conical section 11 is the first flow channel. The large end of the first conical section 11 is used as the inlet of the first flow channel, and the small end is connected to the first straight section 12. The second cylindrical body 20 has a second conical section 21 and a second straight section 22. The internal channel of the second conical section 21 is the third flow channel. The large end of the second conical section 21 is used as the outlet of the third flow channel, and the small end is connected to the second straight section 22. The outer diameter of the second straight section 22 is equal to the inner diameter of the first straight section 12. The second straight section 22 is sealed to the first straight section 12 by complete insertion to form the second flow channel.

[0045] During exhaust, the airflow gradually increases in velocity as it passes through the first flow channel with a gradually decreasing inner diameter, rapidly expelling oxides and other impurities from the furnace. Simultaneously, the gradually decreasing cross-sectional area slows heat loss and reduces pressure fluctuations. As the increased velocity airflow enters the second flow channel, it enhances its impact on the inner walls of the first and second straight cylindrical sections 12 and 22, reducing the accumulation of oxides and other impurities. The straight cylindrical structure, with its constant cross-sectional area, stabilizes the furnace pressure. Further, as the airflow enters the third flow channel with a gradually increasing inner diameter, the rapid change in cross-sectional area causes airflow vibration, preventing oxides and other impurities from accumulating on the inner wall of the second conical section 21. This allows for rapid flow of oxides and other impurities at easily clogged locations. Simultaneously, the reduced airflow velocity creates a slow airflow, which is then caught up with and merged by the subsequently discharged fast airflow, forming vortices and airflow oscillations. This causes any oxides and other impurities that may accumulate at the outlet of the third flow channel to fall off, reducing channel blockage and lowering the oxygen content in the furnace. Compared with the prior art, this utility model can quickly discharge oxides and other impurities in the furnace by using a first flow channel with a gradually narrowing inner diameter, a second flow channel with a constant inner diameter, and a third flow channel with a gradually expanding inner diameter. Moreover, each flow channel is less prone to ash accumulation, reducing the possibility of blockage after long-term operation, and can also reduce heat loss in the furnace.

[0046] The inner diameter of the large end of the first conical section 11 is equal to the inner diameter of the large end of the second conical section 21. This avoids turbulent airflow inside the furnace, helps stabilize the gas pressure inside the furnace, effectively reduces heat loss, and does not affect the rapid discharge of oxides and other impurities inside the furnace.

[0047] See Figure 4 As shown, an annular guiding cone surface 23 is provided on the inner side of the end of the second straight cylindrical section 22 away from the second conical section 21. The large diameter portion of the guiding cone surface 23 extends to the inner diameter opening corresponding to the small end of the first conical section 11. In this way, the resistance of the airflow entering the second flow channel can be reduced, its flow velocity can be further increased, and heat loss in the furnace can be reduced.

[0048] A guide bar 24 extending spirally along the airflow direction is provided on the inner circumference of the second straight cylindrical section 22. The guide bar 24 protrudes from the inner circumference of the second straight cylindrical section 22 to guide the airflow. Through the protruding guide bar 24, the airflow can be guided to flow in a spiral manner, increasing its flow velocity, accelerating the discharge of oxides and other impurities in the furnace, rapidly reducing the oxygen content in the furnace, and improving production quality. At the same time, the spiral airflow has strong fluidity and a certain vibration capability, which will disturb oxides and other impurities, preventing oxides and other impurities from accumulating or adhering in the flow channel and affecting exhaust efficiency.

[0049] The inner wall of the first cylindrical section 12 is provided with internal threads (see details). Figure 2 As shown), the outer circumferential wall of the second straight section 22 is provided with external threads (see details). Figure 3As shown, the second straight cylindrical section 22 is threadedly connected to the first straight cylindrical section 12 to achieve complete insertion and sealing. The second straight cylindrical section 22 and the first straight cylindrical section 12 form a sleeve structure through the threaded connection. Adjusting its screw-in depth can change the height (length) of the gas guide tube, thereby adapting it to the thermal field thickness of different single crystal furnace bottoms and improving the applicability of this gas guide tube.

[0050] In this embodiment, both the first cylinder 10 and the second cylinder 20 are preferably made of carbon-carbon composite material. Compared with traditional graphite air guides, carbon-carbon composite material has higher strength, making the air guide of this application less prone to damage during disassembly and assembly, and reducing maintenance costs.

[0051] On the other hand, this invention provides a single crystal furnace (not shown in the figure) including the gas guide tube described above. By using the aforementioned gas guide tube, the single crystal furnace can ensure the quality of crystal pulling.

[0052] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the technical solutions of this utility model. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of this utility model patent.

Claims

1. A gas guide tube for a single crystal furnace, disposed at the exhaust port at the bottom of the single crystal furnace, characterized in that, The air delivery tube includes: The first cylinder and the second cylinder are connected to each other to form a first flow channel, a second flow channel and a third flow channel that are connected in sequence; The first flow channel inlet faces the inside of the single crystal furnace, and its inner diameter gradually decreases along the airflow direction; the third flow channel outlet faces the outside of the single crystal furnace, and its inner diameter gradually increases along the airflow direction. The first cylindrical body has a first conical part and a first straight part. The internal channel of the first conical part is the first flow channel. The large end of the first conical part is used as the inlet of the first flow channel, and the small end is connected to the first straight part. The second cylinder has a second conical section and a second straight section. The internal channel of the second conical section is the third flow channel. The large end of the second conical section is used as the outlet of the third flow channel, and the small end is connected to the second straight section. The outer diameter of the second straight cylindrical section is equal to the inner diameter of the first straight cylindrical section, and the second straight cylindrical section is sealed to the first straight cylindrical section by complete insertion to form the second flow channel.

2. The gas guide tube for a single crystal furnace according to claim 1, characterized in that, The inner diameter of the large end of the first conical section is equal to the inner diameter of the large end of the second conical section.

3. The gas guide tube for a single crystal furnace according to claim 1 or 2, characterized in that: An annular drainage cone surface is provided on the inner side of the end of the second straight cylinder that is away from the second conical cylinder; The large-diameter portion of the drainage cone extends to the inner diameter opening corresponding to the small end of the first cone.

4. The gas guide tube for a single crystal furnace according to claim 3, characterized in that: The second straight cylindrical section has a guide bar that extends spirally along the airflow direction on its inner circumferential wall. The guide strip protrudes from the inner circumference of the second straight cylinder to guide the airflow.

5. The gas guide tube for a single crystal furnace according to claim 1 or 4, characterized in that: The inner circumferential wall of the first straight cylindrical section is provided with internal threads; The outer circumferential wall of the second straight cylindrical section is provided with external threads; The second straight section is threadedly connected to the first straight section to achieve complete insertion and sealing.

6. The gas guide tube for a single crystal furnace according to claim 1, characterized in that, Both the first and second cylinders are made of carbon-carbon composite materials.

7. A single crystal furnace, characterized in that, Includes the gas guide tube for a single crystal furnace as described in any one of claims 1 to 6.

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