Device and method for cleaning exhaust pipeline of single crystal furnace and single crystal furnace

Abstract

The invention provides a single crystal furnace exhaust pipeline cleaning device and method and a single crystal furnace, and belongs to the technical field of pipeline cleaning. Comprising a spiral cleaning mechanism, a driving mechanism and a gas conveying mechanism, and a driving shaft pipe is arranged on the driving mechanism in the axial direction of an exhaust pipeline; the driving mechanism is mounted at one end far away from an inlet of the single crystal furnace exhaust pipeline, and the spiral cleaning mechanism is mounted on one side, far away from the driving mechanism, of the driving shaft pipe, so that the spiral cleaning mechanism is close to the inlet of the single crystal furnace exhaust pipeline; the driving mechanism is used for driving the driving shaft pipe to drive the spiral cleaning mechanism to rotate so as to clean oxides on the inner wall of the exhaust pipeline; the gas conveying mechanism is installed on the side, close to the driving mechanism, of the driving shaft pipe so as to convey gas into the exhaust pipeline, and oxide cleaned by the spiral cleaning mechanism is prevented from falling on the driving mechanism. By arranging the gas conveying mechanism, oxides at the corner of the exhaust pipeline of the single crystal furnace are cleaned up.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline cleaning, and in particular to a device and method for cleaning an exhaust pipeline of a single crystal furnace, and a single crystal furnace. Background Art

[0002] Single crystal silicon rods are widely used in the photovoltaic and semiconductor fields. Single crystal furnaces are the main equipment for producing single crystal silicon rods. Silicon crystals are generally heated to a molten state using a graphite heater, and single crystal silicon rods are pulled using techniques such as the Czochralski method. During the single crystal silicon rod pulling process, a large amount of oxides are produced in the furnace. These oxides are transported through the exhaust duct inside the furnace to the exhaust pipe outside the furnace and finally discharged from the furnace. The entrance of the exhaust pipe at the bottom of the furnace, where the exhaust duct inside the furnace meets the exhaust pipe outside the furnace, is at the junction of hot and cold. Oxides are easily deposited and adsorbed here as their temperature drops. The longer the operation time, the more oxides accumulate, eventually clogging the exhaust port, causing the exhaust system to fail, ultimately affecting the crystallization effect and quality.

[0003] In the prior art, for example, Chinese invention patent application number CN202323422104.5 specifically discloses a novel online ash cleaning device for a single crystal furnace pipeline, and specifically discloses a ash cleaning mechanism disposed within the pipeline and a drive mechanism connected to the ash cleaning mechanism. The drive mechanism includes a mounting bracket disposed at the bottom of the pipeline, a magnetic fluid detachably mounted at the bottom of the mounting bracket, a motor mounted at the bottom of the magnetic fluid, and a rotating shaft plugged into the top of the magnetic fluid from top to bottom. The ash cleaning mechanism is mounted on the rotating shaft, and an ash retaining groove is provided on the rotating shaft at the bottom of the pipeline. Since the ash cleaning mechanism is disposed within the pipeline near the inlet of the single crystal furnace pipeline, and the drive mechanism connected thereto is located at the corner of the single crystal furnace pipeline, the cleaned oxides will fall into the magnetic fluid when passing through the corner. Therefore, the patent provides an ash retaining groove above the magnetic fluid to prevent the oxides from falling into the magnetic fluid and affecting the operation of the magnetic fluid. However, some of the cleaned oxides will still accumulate in the ash retaining groove and cannot be cleaned, thereby preventing the oxides at the corners of the single crystal furnace pipeline from being cleaned. Summary of the Invention

[0004] In view of this, the present invention provides a single crystal furnace exhaust duct cleaning device, method and single crystal furnace to solve the technical problem that the existing cleaning device cannot clean the oxides at the corners of the single crystal furnace duct.

[0005] The technical solution adopted by the present invention to solve its technical problem is: A single crystal furnace exhaust pipe cleaning device comprises a spiral cleaning mechanism, a driving mechanism, and a gas delivery mechanism, wherein the driving mechanism is provided with a driving shaft tube along the axial direction of the exhaust pipe; The driving mechanism is installed at one end away from the inlet of the single crystal furnace exhaust duct, and the spiral cleaning mechanism is installed on the side of the driving shaft tube away from the driving mechanism, so that the spiral cleaning mechanism is close to the inlet of the single crystal furnace exhaust duct; The driving mechanism is used to drive the driving shaft tube to drive the spiral cleaning mechanism to rotate, thereby cleaning the oxides on the inner wall of the exhaust pipe; The gas delivery mechanism is installed on a side of the drive shaft tube close to the drive mechanism to deliver gas into the exhaust pipe to prevent the oxides cleaned by the spiral cleaning mechanism from falling on the drive mechanism.

[0006] Preferably, the spiral cleaning mechanism is a spiral scraper.

[0007] Preferably, the drive shaft tube includes a fixed part and a rotating part, the fixed part is sleeved on the output shaft of the drive mechanism, the rotating part is rotatably connected to the upper end of the fixed part and is connected to the output shaft of the drive mechanism to drive the rotating part to rotate through the drive mechanism.

[0008] Preferably, the interior of the drive shaft tube is hollow, and a plurality of through holes are provided on the tube wall of the drive shaft tube at positions corresponding to the spiral cleaning mechanism, and an air guide hole with the air outlet obliquely upward is provided on the tube wall of the drive shaft tube near the driving mechanism.

[0009] Preferably, the gas inlet of the gas delivery mechanism is connected to the argon flowmeter of the single crystal furnace, and the gas outlet of the gas delivery mechanism is connected to the side wall of the fixed part to deliver argon to the interior of the drive shaft tube and flow out from the through hole.

[0010] The present invention also provides a method for cleaning the exhaust duct of a single crystal furnace, which is applied to the above-mentioned single crystal furnace exhaust duct cleaning device, comprising the following steps: S1. When an exhaust pipe cleaning signal is detected, the driving mechanism is started, and the driving mechanism controls the driving shaft tube to rotate, driving the spiral cleaning mechanism to rotate and clean the oxides on the inner wall of the exhaust pipe; S2. Start the gas delivery mechanism to deliver gas from bottom to top into the exhaust pipe of the single crystal furnace.

[0011] Preferably, in step S1, the method further comprises: when crystal pulling starts, sending an exhaust duct cleaning signal to a controller of the single crystal furnace.

[0012] Preferably, in step S1 , the pressure and argon gas in the single crystal furnace are adjusted to control the amount of oxides generated in the single crystal furnace.

[0013] Preferably, a vacuum pump is connected to the outlet of the single crystal furnace exhaust pipe, and the vacuum pump is a variable frequency vacuum pump. In step S1, the pressure, argon gas and frequency of the vacuum pump in the single crystal furnace are adjusted to control the amount of oxides produced in the single crystal furnace.

[0014] The present invention also provides a single crystal furnace, comprising a single crystal furnace exhaust duct, wherein the single crystal furnace exhaust duct is installed with the single crystal furnace exhaust duct cleaning device as described above.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a spiral cleaning mechanism near the entrance of the single crystal furnace exhaust duct to clean oxides adhered to the inner wall of the single crystal furnace exhaust duct. Simultaneously, a gas delivery mechanism is provided on the drive mechanism to clean the corners of the single crystal furnace exhaust duct. When it is necessary to clean oxides in the single crystal furnace exhaust duct, the drive mechanism is activated, causing the drive shaft tube to begin rotating, driving the spiral cleaning mechanism mounted on the drive shaft tube to begin rotating. The spiral cleaning mechanism scrapes oxides off the inner wall of the exhaust duct during rotation, and the scraped oxides are removed by the suction force of the vacuum pump at the outlet of the single crystal furnace exhaust duct. Simultaneously, the gas delivery mechanism is activated to blow upward, so that the oxides removed by the spiral cleaning mechanism move upward when approaching the drive mechanism, and are then removed by the vacuum pump at the outlet of the single crystal furnace exhaust duct, preventing the oxides from falling on the drive mechanism, thereby completely cleaning the oxides at the corners of the single crystal furnace exhaust duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of the exhaust duct of the single crystal furnace of the present invention.

[0017] Figure 2 It is a structural schematic diagram of the single crystal furnace exhaust duct cleaning device of the present invention.

[0018] In the figure: single crystal furnace 1, single crystal furnace exhaust pipe 11, argon flowmeter 12, spiral cleaning mechanism 100, driving mechanism 200, driving shaft tube 210, fixed part 211, rotating part 212, through hole 213, gas guide hole 214, gas delivery mechanism 300, magnetic fluid seal 400. DETAILED DESCRIPTION

[0019] The technical solutions and technical effects of the embodiments of the present invention are further elaborated below in conjunction with the accompanying drawings of the present invention.

[0020] Please also see Figure 1 and Figure 2, a single crystal furnace exhaust duct cleaning device includes a spiral cleaning mechanism 100, a driving mechanism 200, and a gas conveying mechanism 300. A driving shaft tube 210 is provided on the driving mechanism 200 along the axial direction of the exhaust duct; the driving mechanism 200 is installed at one end away from the inlet of the single crystal furnace exhaust duct, and the spiral cleaning mechanism 100 is installed on the side of the driving shaft tube 210 away from the driving mechanism 200, so that the spiral cleaning mechanism 100 is close to the inlet of the single crystal furnace exhaust duct; the driving mechanism 200 is used to drive the driving shaft tube 210 to drive the spiral cleaning mechanism 100 to rotate, so as to clean the oxides on the inner wall of the exhaust duct; the gas conveying mechanism 300 is installed on the side of the driving shaft tube 210 close to the driving mechanism 200 to convey gas into the exhaust duct to prevent the oxides cleaned by the spiral cleaning mechanism 100 from falling on the driving mechanism 200.

[0021] Since the oxides generated by the single crystal furnace mainly accumulate at the entrance of the single crystal furnace exhaust duct, that is, the junction of the exhaust duct inside the furnace and the exhaust duct outside the furnace, the present invention provides a spiral cleaning mechanism 100 near the entrance of the single crystal furnace exhaust duct to clean the oxides attached to the inner wall of the single crystal furnace exhaust duct 11. At the same time, a gas delivery mechanism 300 is provided on the drive mechanism 200 to clean the corners of the single crystal furnace exhaust duct 11. When it is necessary to clean the oxides in the single crystal furnace exhaust duct, the drive mechanism 200 is started, causing the drive shaft tube 210 to start rotating, driving the spiral cleaning mechanism 100 installed on the drive shaft tube 210 to start rotating. The spiral cleaning mechanism 100 scrapes the oxides on the inner wall of the exhaust duct during rotation, and the scraped oxides are pumped away by the suction force of the vacuum pump at the outlet of the single crystal furnace exhaust duct. At the same time, the gas delivery mechanism 300 is started to blow upward, so that the oxides cleaned by the spiral cleaning mechanism 100 move upward when approaching the driving mechanism 200, and are then sucked away by the vacuum pump at the outlet of the single crystal furnace exhaust duct, preventing the oxides from falling on the driving mechanism, thereby cleaning the oxides at the corners of the single crystal furnace exhaust duct.

[0022] Typically, the exhaust duct of a single crystal furnace is connected to a vacuum pump. During the single crystal pulling process, a vacuum pump is typically used to extract air from the furnace and discharge it through the exhaust duct, creating a vacuum state within the furnace. Therefore, in the present application, after the spiral cleaning mechanism 100 has removed oxides from the inner wall of the exhaust duct, a vacuum pump can be used to suck the oxides out of the exhaust duct.

[0023] Furthermore, the spiral cleaning mechanism 100 is a spiral scraper. Specifically, when the driving mechanism 200 is started, the driving mechanism 200 drives the driving shaft tube 210 to rotate, and the spiral scraper installed on the driving shaft tube 210 rotates along with the driving shaft tube 210. During the rotation, the spiral scraper scrapes off the oxides on the inner wall of the exhaust pipe. The scraped oxides are transported downward by the spiral scraper and then sucked away by the vacuum pump. Designing the spiral cleaning mechanism to be spiral-shaped can, on the one hand, increase the cleaning area of ​​the scraper and improve the cleaning efficiency; on the other hand, it can limit the path of the oxide falling and transport it downward in a spiral path, reducing the probability of the oxide falling into the corner of the exhaust pipe, thereby further improving the cleaning efficiency of the corner of the single crystal furnace exhaust pipe.

[0024] Further, see Figure 2 The drive shaft tube 210 includes a fixed portion 211 and a rotating portion 212. The fixed portion 211 is sleeved on the output shaft of the drive mechanism 200. The rotating portion 212 is rotatably connected to the upper end of the fixed portion 211 and is connected to the output shaft of the drive mechanism 200 so as to be driven to rotate by the drive mechanism 200. Specifically, the fixed portion 212 is sleeved on the output shaft of the drive mechanism 200, and one end is rotatably connected to the rotating portion 212, and the other end is fixedly connected to the drive mechanism 200. The spiral cleaning mechanism 100 is installed on the side of the rotating portion 212 away from the drive mechanism 100. When the drive mechanism 200 is started, the drive mechanism 200 drives the rotating portion 212 to rotate, and the rotating portion 212 drives the spiral cleaning mechanism 100 to rotate, so as to clean the oxides on the inner wall of the exhaust pipe of the single crystal furnace.

[0025] Further, see Figure 1The interior of the drive shaft tube 210 is hollow, and a plurality of through holes 213 are formed on the wall of the drive shaft tube 210 at positions corresponding to the spiral cleaning mechanism 100. A gas guide hole 214 with the gas outlet facing obliquely upward is provided on the wall of the drive shaft tube 210 near the drive mechanism 200. Specifically, the hollow interior of the drive shaft tube 210 facilitates the gas delivery mechanism 300 to deliver gas to the entire drive shaft tube 210. The plurality of through holes 213 are formed on the wall of the drive shaft tube 210 at positions corresponding to the spiral cleaning mechanism 100. When the gas delivery mechanism 300 delivers gas to the drive shaft tube 210, the gas can flow outward through the through holes 213. When the spiral cleaning mechanism 100 scrapes oxides off the inner wall of the exhaust pipe, the airflow through the through holes 213 prevents the oxides from adhering to the scraper of the spiral cleaning mechanism 100 and the drive shaft sleeve 210. An air guide hole 214 with the air outlet facing obliquely upward is provided on the tube wall of the drive shaft tube 210 near the drive mechanism 200. When the gas delivery mechanism 300 delivers gas to the drive shaft tube 210, the gas flows upward from the air guide hole 214, thereby blowing the oxides close to the drive mechanism 200 upwards, preventing the oxides from falling on the drive mechanism, and further cleaning the oxides at the corners of the single crystal furnace exhaust duct.

[0026] Further, see Figure 1 The gas inlet of the gas delivery mechanism 300 is connected to the argon flowmeter 11 of the single crystal furnace, and the gas outlet of the gas delivery mechanism 300 is connected to the side wall of the fixing portion 212 to deliver argon to the interior of the drive shaft tube 210 and flow out from the through hole 211. Specifically, the gas delivered by the present invention is argon. As an inert gas, argon is not easy to react with the inner wall of the exhaust pipe and oxides. At the same time, the gas inlet and outlet of the gas delivery mechanism 300 are provided with valves. When the single crystal furnace exhaust pipe cleaning device is started, the argon flowmeter of the single crystal furnace and the valves of the gas inlet and outlet of the gas delivery mechanism 300 are opened, so that the argon in the argon flowmeter passes through the gas delivery mechanism 300 and enters the drive shaft tube 210.

[0027] In some embodiments, a water cooling pipe is provided at the furnace bottom plate pipe opening, and the furnace bottom plate pipe of the single crystal furnace is cooled by the water cooling pipe, so that the temperature of the oxide in the single crystal furnace is reduced, and the condensation and accumulation of the oxide in the single crystal furnace in the exhaust pipe are accelerated, and then the oxide is cleaned by the single crystal furnace exhaust pipe cleaning device of the present invention, thereby improving the cleaning efficiency of the oxide in the single crystal furnace.

[0028] In some embodiments, the driving force generated by the gas delivery mechanism when delivering gas is less than the suction force of the vacuum pump. During the crystal pulling process, oxides in the exhaust pipe are primarily discharged from the exhaust pipe by the suction force of the vacuum pump and the driving force of the argon gas in the furnace. The function of the gas delivery mechanism is only to blow oxides near the drive mechanism upward to facilitate extraction by the vacuum pump. Therefore, the driving force generated by the gas delivery mechanism when delivering gas must be less than the suction force of the vacuum pump to ensure that it can be extracted by the vacuum pump. It must also be less than the flow rate of argon gas in the furnace to prevent the oxides from being blown back into the furnace.

[0029] Further, see Figure 2 The driving mechanism 200 is arranged outside the exhaust pipe of the single crystal furnace, and the driving mechanism 200 and the exhaust pipe 11 of the single crystal furnace are sealed by a magnetic fluid seal 400.

[0030] In some embodiments, the single crystal furnace exhaust duct cleaning device further includes a dust collection mechanism, which is disposed between the exhaust duct and the vacuum pump to collect the cleaned oxides. Specifically, the single crystal furnace exhaust duct of the present application is used to clean the oxides on the inner wall of the exhaust duct during the operation of the single crystal furnace, while the exhaust duct of a single crystal furnace is generally connected to a vacuum pump. During the process of pulling single crystals, a vacuum pump is typically used to extract the air in the furnace and discharge it from the exhaust duct of the single crystal furnace, leaving the furnace in a vacuum state. Therefore, after the spiral cleaning mechanism 100 is used to clean the oxides on the inner wall of the exhaust duct, the existing vacuum pump can be used to suck them out of the exhaust duct, eliminating the need for an additional dust collection device, thereby reducing costs. At the same time, a dust collection mechanism is disposed between the exhaust duct and the vacuum pump to collect the oxides sucked out by the vacuum pump and prevent them from entering the vacuum pump. The linkage between the vacuum pump and the dust collection mechanism can, on the one hand, accelerate the cleaning efficiency of the oxides in the exhaust duct of the single crystal furnace, and on the other hand, can also collect the cleaned oxides, preventing the cleaned oxides from falling out of the exhaust duct and scattering freely.

[0031] In some embodiments, the dust collection mechanism includes a removable filter. After the vacuum pump sucks the cleaned oxides out of the exhaust duct, the oxides are filtered and intercepted by the filter and do not fall into the vacuum pump. After the single crystal furnace exhaust duct cleaning device stops working, the filter can be removed for cleaning.

[0032] In some embodiments, the single crystal furnace exhaust duct cleaning device of the present application can be manually controlled. That is, when a worker determines that the oxides on the inner wall of the single crystal furnace exhaust duct need to be cleaned, the worker manually activates the drive mechanism 200, causing the drive shaft tube 210 to rotate, thereby driving the spiral cleaning mechanism 100 to rotate and clean the oxides. In some embodiments, the single crystal furnace exhaust duct cleaning device can also be activated on a timer basis, thereby automatically cleaning the oxides on the inner wall of the single crystal furnace exhaust duct at a regular interval.

[0033] In some embodiments, the drive mechanism 200 may utilize a servo motor, the input end of which is connected to a controller, and the output end of which is connected to the rotating portion 212 of the drive shaft tube 210. The controller utilizes an existing single crystal furnace PLC control system, electrically connecting the servo motor to the single crystal furnace PLC control system. The speed and direction of the servo motor are controlled by the single crystal furnace PLC control system, enabling the knocking and cleaning portion to achieve various rotation schemes, including forward, reverse, intermittent, and swinging, to effectively remove oxides.

[0034] The present invention also provides a method for cleaning the exhaust duct of a single crystal furnace, which is applied to the above-mentioned single crystal furnace exhaust duct cleaning device, comprising the following steps: S1. When an exhaust pipe cleaning signal is detected, the driving mechanism is started, and the driving mechanism controls the driving shaft tube to rotate, driving the spiral cleaning mechanism to rotate and clean the oxides on the inner wall of the exhaust pipe; S2. Start the gas delivery mechanism to deliver gas from bottom to top into the exhaust pipe of the single crystal furnace.

[0035] When the single crystal furnace detects an exhaust duct cleaning signal, the present invention activates a drive mechanism through the single crystal furnace controller. The output shaft of the drive mechanism begins to rotate, driving the drive shaft tube connected to it to rotate. The drive shaft tube drives the spiral cleaning mechanism to rotate. During rotation, the spiral cleaning mechanism contacts the inner wall of the exhaust duct and scrapes off oxides on the inner wall of the exhaust duct via a scraper. While the spiral cleaning mechanism is operating, a gas delivery mechanism is activated to blow air from the bottom to the top of the exhaust duct, causing oxides near the drive mechanism to move upward and be extracted by the vacuum pump, thereby fully cleaning oxides at the corners of the single crystal furnace exhaust duct.

[0036] Furthermore, in step S1, the method further includes: sending an exhaust duct cleaning signal to the controller of the single crystal furnace when crystal pulling begins. Specifically, when the charging process is completed, the single crystal furnace lid is closed, and the charging process begins, the exhaust duct cleaning signal is sent to the controller of the single crystal furnace. This allows oxides that enter the exhaust duct to be cleaned promptly, preventing them from adhering to and solidifying on the inner wall of the exhaust duct before cleaning, thereby improving the cleaning efficiency of the single crystal furnace exhaust duct cleaning device.

[0037] In some embodiments, to precisely clean oxides from the inner wall of the single crystal furnace exhaust duct and reduce energy consumption of the single crystal furnace exhaust duct cleaning device, the driving mechanism may be activated only when a certain amount of oxides is detected on the inner wall of the exhaust duct. As an embodiment, an oxide detection device may be installed on the single crystal furnace exhaust duct cleaning device to detect the presence of oxides on the inner wall of the single crystal furnace exhaust duct and the thickness of the oxides. Based on the thickness, the device may be activated to clean the inner wall of the single crystal furnace exhaust duct.

[0038] Furthermore, in step S1, the pressure and argon gas in the single crystal furnace are adjusted to control the amount of oxides produced in the single crystal furnace. During the crystal pulling process and the single crystal growth process, oxidizing components in the atmosphere may cause the appearance of metallic impurities in the single crystal, thereby affecting the purity and performance of the crystal. Appropriately adjusting the furnace pressure and argon gas in the single crystal furnace can reduce the production of oxides, thereby reducing the workload of the single crystal furnace exhaust duct cleaning device and improving the cleaning efficiency of the single crystal furnace exhaust duct cleaning device. Specifically, with respect to the furnace pressure, the production of oxides can be reduced by lowering the furnace pressure. Lowering the furnace pressure will reduce the average degree of freedom of gas molecules, reducing collisions between gas molecules, thereby reducing the contact between oxygen molecules and the crystal rod. Lowering the furnace pressure will increase the gas diffusion rate, thereby better removing SiO gas and preventing it from being reoxidized into solid oxides, thereby reducing the oxygen content. As for argon gas, the introduction of inert gas can effectively reduce the concentration of oxides and inhibit the adsorption of impurities in the crystal, thereby increasing the purity and uniformity of the crystal. In addition, the introduction of argon gas can also stabilize the reaction atmosphere, improve reaction efficiency and crystal growth rate. Therefore, passing argon through the single crystal furnace is an important means to ensure the high purity and uniformity of the crystal. As an inert gas, argon can effectively isolate oxygen from contact with high-temperature molten silicon and prevent oxidation reactions. When the single crystal furnace is operated in an argon environment, the volatile SiO gas generated by the reaction between the quartz crucible and the molten silicon will be quickly carried away by the argon, reducing secondary oxidation. The flow of argon can also balance the temperature distribution in the furnace, reduce excessive erosion of the quartz crucible caused by local high temperature, and suppress the main source of oxygen. However, part of the oxides in the single crystal furnace are used as dopants to ensure the resistivity and product quality of the single crystal silicon. Therefore, the oxides in the single crystal furnace cannot be completely eliminated. The generation of oxides must be reduced as much as possible while ensuring the qualified rate of single crystal silicon. Therefore, in the present invention, the pressure and argon in the single crystal furnace are adjusted, specifically, the argon flow rate is 50-100slpm, and the pressure in the single crystal furnace is 8-40kPa.

[0039] Furthermore, the outlet of the single crystal furnace exhaust duct is connected to a vacuum pump, which is a variable frequency vacuum pump. In step S1, the pressure, argon gas and frequency of the vacuum pump in the single crystal furnace are regulated to control the generation of oxides in the single crystal furnace. Wherein, it is first necessary to ensure that there is a certain amount of oxide in the single crystal furnace to ensure the resistivity and quality of the single crystal silicon drawn. On the basis of having a fixed value of oxide, the generation of oxides in the single crystal furnace is reduced by regulating the pressure, argon gas and frequency of the vacuum pump in the single crystal furnace. The vacuum pump can remove the oxides in the single crystal furnace when working. If the frequency of the vacuum pump is large, the oxides removed are more, and if the frequency is small, the oxides removed are less. If the frequency of the vacuum pump is fixed, then as the oxides in the furnace increase, it is necessary to reduce the furnace pressure and argon gas to eliminate the increased oxides. If the vacuum pump is designed as a variable frequency vacuum pump, the pressure, argon gas and frequency of the vacuum pump can be adjusted synchronously according to demand to achieve a better effect of reducing oxides. As an implementation method, first ensure that there is a constant value of oxide A in the single crystal furnace. If the oxide in the furnace increases, the furnace pressure and argon gas can be reduced, and the frequency of the vacuum pump can be increased; if the oxide in the furnace decreases, the furnace pressure and argon gas can be increased, and the frequency of the vacuum pump can be reduced.

[0040] Please see Figure 1 The present invention also provides a single crystal furnace 1, comprising a single crystal furnace exhaust pipe 11, in which the single crystal furnace exhaust pipe 11 is installed the single crystal furnace exhaust pipe cleaning device as described above.

[0041] The above disclosure is only a preferred embodiment of the present invention, and it is certainly not intended to limit the scope of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A single crystal furnace exhaust pipe cleaning device, characterized in that: It includes a spiral cleaning mechanism, a driving mechanism, and a gas delivery mechanism. The driving mechanism is provided with a driving shaft tube along the axial direction of the exhaust pipe. The driving mechanism is installed at one end away from the inlet of the single crystal furnace exhaust duct, and the spiral cleaning mechanism is installed on the side of the driving shaft tube away from the driving mechanism, so that the spiral cleaning mechanism is close to the inlet of the single crystal furnace exhaust duct; The driving mechanism is used to drive the driving shaft tube to drive the spiral cleaning mechanism to rotate, thereby cleaning the oxides on the inner wall of the exhaust pipe; The gas delivery mechanism is installed on a side of the drive shaft tube close to the drive mechanism to deliver gas into the exhaust pipe to prevent the oxides cleaned by the spiral cleaning mechanism from falling on the drive mechanism.

2. The single crystal furnace exhaust pipe cleaning device according to claim 1, characterized in that: The spiral cleaning mechanism is a spiral scraper.

3. The single crystal furnace exhaust pipe cleaning device according to claim 2, characterized in that: The driving shaft tube includes a fixed part and a rotating part. The fixed part is sleeved on the output shaft of the driving mechanism. The rotating part is rotatably connected to the upper end of the fixed part and is connected to the output shaft of the driving mechanism to drive the rotating part to rotate through the driving mechanism.

4. The single crystal furnace exhaust pipe cleaning device according to claim 3, characterized in that: The interior of the drive shaft tube is hollow, and a plurality of through holes are opened on the tube wall of the drive shaft tube at positions corresponding to the spiral cleaning mechanism. An air guide hole with an air port obliquely upward is provided on the tube wall of the drive shaft tube near the driving mechanism.

5. The single crystal furnace exhaust pipe cleaning device according to claim 4, characterized in that: The gas inlet of the gas delivery mechanism is connected to the argon flow meter of the single crystal furnace, and the gas outlet of the gas delivery mechanism is connected to the side wall of the fixing part to deliver argon to the interior of the drive shaft tube and flow out from the through hole.

6. A method for cleaning the exhaust duct of a single crystal furnace, applied to the single crystal furnace exhaust duct cleaning device according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. When an exhaust pipe cleaning signal is detected, the driving mechanism is started, and the driving mechanism controls the driving shaft tube to rotate, driving the spiral cleaning mechanism to rotate and clean the oxides on the inner wall of the exhaust pipe; S2. Start the gas delivery mechanism to deliver gas from bottom to top into the exhaust pipe of the single crystal furnace.

7. The method for cleaning the exhaust pipe of a single crystal furnace according to claim 6, characterized in that: In step S1 , the method further includes: when crystal pulling starts, sending an exhaust duct cleaning signal to a controller of the single crystal furnace.

8. The method for cleaning the exhaust pipe of a single crystal furnace according to claim 7, characterized in that: In step S1 , the pressure and argon gas in the single crystal furnace are adjusted to control the amount of oxides generated in the single crystal furnace.

9. The method for cleaning the exhaust pipe of a single crystal furnace according to claim 8, wherein a vacuum pump is connected to the outlet of the exhaust pipe of the single crystal furnace, and the vacuum pump is a variable frequency vacuum pump, characterized in that: In step S1 , the pressure, argon gas, and frequency of the vacuum pump in the single crystal furnace are adjusted to control the amount of oxides generated in the single crystal furnace.

10. A single crystal furnace, characterized in that: It comprises a single crystal furnace exhaust duct, in which the single crystal furnace exhaust duct is installed the single crystal furnace exhaust duct cleaning device according to any one of claims 1 to 5.

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