Cleaning method and cleaning system for polycrystalline silicon reduction furnace bell jar

Abstract

The invention discloses a cleaning method and a cleaning device for a bell jar of a polycrystalline silicon reduction furnace, relates to the technical field of bell jar cleaning, and mainly aims to provide the cleaning method for the bell jar of the polycrystalline silicon reduction furnace, which can improve the cleaning quality of the bell jar and prolong the cleaning period of the bell jar. According to the main technical scheme, the embodiment of the invention provides the cleaning method for the polycrystalline silicon reduction furnace bell jar. The method comprises the following steps: continuously spraying and cleaning the inner wall of the bell jar by adopting high-pressure desalted water; a 5-15% NaOH solution is adopted to conduct circulating jet cleaning on the inner wall of the bell jar; performing three-section rinsing on the inner wall of the bell jar by adopting high-pressure desalted water, wherein the pressure of the three-section rinsing is gradually reduced; and carrying out pulse purging on the inner wall of the bell jar by using clean hot air. The device is mainly used for cleaning the bell jar.

Description

Technical Field

[0001] The present invention relates to the technical field of bell jar cleaning, and particularly to a cleaning method and a cleaning system for a bell jar of a polysilicon reduction furnace. Background Art

[0002] The bell jar of the reduction furnace is a core component in polysilicon production equipment, mainly used to form a closed reaction environment during chemical vapor deposition. As the core sealing structure of the reaction chamber, it ensures the stable reaction of silicon cores and gaseous raw materials under high-temperature and high-pressure environments. It is mainly used in the production of polysilicon by the improved Siemens method, covering the demand for high-purity silicon from industrial grade to electronic grade. Since reaction by-products are easily attached to the inner wall, a high-pressure water automatic cleaning system or a special cleaning agent needs to be used for efficient cleaning to avoid contaminating the silicon cores and affecting product quality.

[0003] The existing high-pressure water automatic cleaning system mainly conducts multiple alternating rinses with water or weak alkaline solution. Such a method has the following problems:

[0004] The silicon powder remaining on the surface of the bell jar is not thoroughly removed, resulting in subsequent production pollution;

[0005] During the alternating rinsing process, a large amount of water resources and alkaline solution are wasted;

[0006] The alkaline cleaning solution will remain on the surface of the bell jar, resulting in equipment corrosion. Summary of the Invention

[0007] In view of this, embodiments of the present invention provide a cleaning method and a cleaning system for a bell jar of a polysilicon reduction furnace, and the main purpose is to provide a cleaning method for a bell jar of a polysilicon reduction furnace that can improve the cleaning quality and cleaning cycle of the bell jar.

[0008] To achieve the above object, the present invention mainly provides the following technical solutions:

[0009] On the one hand, embodiments of the present invention provide a cleaning method for a bell jar of a polysilicon reduction furnace, and the method includes the following steps:

[0010] Continuously spray-clean the inner wall of the bell jar with high-pressure demineralized water;

[0011] Circulatingly spray-clean the inner wall of the bell jar with a 5-15% NaOH solution;

[0012] Rinse the inner wall of the bell jar in three stages with high-pressure demineralized water, and the pressure of the three-stage rinse gradually decreases;

[0013] Pulse-blow the inner wall of the bell jar with clean hot air.

[0014] Further, the continuously spray-cleaning the inner wall of the bell jar with high-pressure demineralized water includes:

[0015] Set the injection pressure of the high-pressure demineralized water to 10 - 13 Mpa, the conductivity of the demineralized water < 0.1 μS / cm, and the injection time to 600 s;

[0016] Transport the demineralized water to the cleaning nozzle through a booster pump, and the cleaning nozzle sprays and cleans the inner wall of the bell jar.

[0017] Furthermore, the injection pressure of the NaOH solution is 11 - 14 MPa, and the injection time is 800 s.

[0018] Furthermore, the pressures of the three-stage rinsing are 13 MPa, 10 MPa, and 8 MPa respectively.

[0019] Furthermore, the temperature of the clean hot air is 65 - 80 °C, the dew point temperature is less than -40 °C, and the purging time is 1800 s.

[0020] Furthermore, the on-off interval of the pulse purging is 30 s for purging / 15 s for disconnection.

[0021] On the other hand, the embodiment of the present invention also provides a cleaning device for the bell jar of a polysilicon reduction furnace, and the device includes:

[0022] A placement component, on which the bell jar is placed;

[0023] A liquid supply component, the liquid supply component includes a nozzle, a liquid supply pipeline, a water supply tank, and an alkali liquid tank, the nozzle passes through and extends into the placement component, one end of the liquid supply pipeline is connected to the nozzle, and the other end is connected to the water supply tank and the alkali liquid tank;

[0024] A hot air component, the hot air component includes a blower, a filter, a heater, and an air outlet pipeline, one end of the air outlet pipeline passes through and extends into the placement component, and the other end is sequentially connected to the heater, the filter, and the blower.

[0025] Furthermore, a recovery component, the recovery component includes a discharge pipeline, a waste liquid tank, a water treatment component, and a silicon powder recovery pool, one end of the discharge pipeline is connected to the placement component, and the other end is connected to the waste liquid tank, one end of the water treatment component is connected to the waste liquid tank, and the other end is connected to the silicon powder recovery pool.

[0026] Furthermore, the recovery component further includes a clarification tank, a waste liquid pipeline, and a waste liquid pump, the discharge pipeline is connected to the clarification tank, one end of the waste liquid pipeline is connected to the clarification tank, and the other end is connected to the water treatment component, and the waste liquid pump is arranged on the waste liquid pipeline.

[0027] Further, the recycling component further includes a nitrogen pipeline and a vent pipeline. The nitrogen pipeline is connected to the lye tank and the waste liquid tank, and the vent pipeline is connected to the lye tank, the waste liquid tank and the discharge pipeline.

[0028] Compared with the prior art, the present invention has the following technical effects:

[0029] First, by sequentially performing high-pressure demineralized water jet cleaning, NaOH solution jet cleaning, and three-stage rinsing with high-pressure demineralized water, the cleaning efficiency of the inner wall of the bell jar is significantly improved, the cleaning cycle is shortened, and at the same time, the resource cost and waste treatment cost of cleaning are reduced;

[0030] Second, through an effective cleaning method, the inner wall of the bell jar can be quickly cleaned, the product quality of polysilicon production is improved, and at the same time, the corrosion and damage of the equipment are reduced, and the service life of the equipment is extended;

[0031] Third, by using clean hot air to perform pulse purging on the inner wall of the bell jar, the inner wall of the bell jar can be quickly dried, thereby improving the drying efficiency. Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of a cleaning device for a polysilicon reduction furnace bell jar provided by an embodiment of the present invention;

[0033] Figure 2 It is a flowchart of a cleaning method for a polysilicon reduction furnace bell jar provided by an embodiment of the present invention;

[0034] Figure 3 It is a flowchart of another cleaning method for a polysilicon reduction furnace bell jar provided by an embodiment of the present invention. Detailed Embodiments

[0035] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0036] On the one hand, as Figure 1 and Figure 2 shown, an embodiment of the present invention provides a cleaning method for a polysilicon reduction furnace bell jar, and the method includes the following steps:

[0037] Continuously jet clean the inner wall of the bell jar with high-pressure demineralized water;

[0038] Circulatingly jet clean the inner wall of the bell jar with 5-15% NaOH solution;

[0039] Perform three-stage rinsing on the inner wall of the bell jar with high-pressure demineralized water, and the pressure of the three-stage rinsing gradually decreases;

[0040] Perform pulse purging on the inner wall of the bell jar with clean hot air.

[0041] Compared with the prior art, the present invention has the following technical effects:

[0042] First, by sequentially performing one high-pressure desalted water jet cleaning, NaOH solution jet cleaning, and high-pressure desalted water three-stage rinsing, the cleaning efficiency of the inner wall of the bell jar is significantly improved, the cleaning cycle is shortened, and at the same time, the resource cost of cleaning and the waste disposal cost are reduced;

[0043] Second, the inner wall of the bell jar can be cleaned quickly through an effective cleaning method, which improves the product quality of polysilicon production, reduces corrosion and damage to the equipment, and extends the service life of the equipment;

[0044] Third, using clean hot air to pulse-blow the inner wall of the bell jar can quickly dry the inner wall of the bell jar, thereby improving the drying efficiency.

[0045] Example 1

[0046] An embodiment of the present invention provides a method for cleaning a bell jar of a polysilicon reduction furnace, the method comprising the following steps:

[0047] 101. Use high-pressure desalted water to continuously spray clean the inner wall of the bell jar.

[0048] The inner wall of the bell jar is pre-cleaned with high-pressure desalted water, the main purpose of which is to construct a silicon powder stripping layer. The desalted water is produced by a two-stage reverse osmosis + EDI electrodeionization device, and the resistivity of the produced water is ≥18MΩ·cm. In addition, it is equipped with an online TOC detector (threshold value <5ppb) to prevent the introduction of organic matter. The conductivity of the high-pressure desalted water is <0.1μS / cm. The desalted water in the water supply tank is transported to the nozzle through a booster pump, and the nozzle sprays high-pressure desalted water onto the inner wall of the bell jar. The pressure is controlled at 10-13Mpa, the spraying time is 600s, and the shear force of the high-pressure water flow is >3.5N / mm 2 It can break through the van der Waals force between silicon powder and the inner wall, making the stripping rate ≥ 92%, and avoid metal wear contamination caused by mechanical contact cleaning. Compared with the scraping method, the metal increment is <0.01ppm.

[0049] 102. Use 5-15% NaOH solution to perform cyclic spray cleaning on the inner wall of the bell jar.

[0050] The inner wall of the bell jar is cleaned by alkaline activation with a 5-15% NaOH solution. The main purpose is to remove the chemical passivation layer. The purity of the NaOH solution is ≥99.9%. The NaOH solution is loaded in an alkali tank. The NaOH solution is delivered to the nozzle by a plunger pump. The plunger is a ceramic reciprocating pressure boosting plunger pump with a pressure resistance of 20 MPa to avoid Fe ion contamination. The nozzle sprays the inner wall of the bell jar in a cycle. The spraying pressure is controlled at 11-14 Mpa, and the spraying time is 800 s, so that the impurities on the inner wall of the bell jar are decomposed into Si-O-Si bonds in an alkaline environment, dissolving the surface passivation layer and releasing the encapsulated Fe / Ni particles. The removal rate of metal impurities is ≥98%.

[0051] 103. The inner wall of the bell jar is rinsed in three stages with high-pressure demineralized water, and the pressure of the three-stage rinsing gradually decreases.

[0052] After the NaOH solution flushing is completed, first rinse with demineralized water at a pressure of 13 Mpa for 200 s, then reduce the pressure of the demineralized water to 10 Mpa and continue rinsing for 200 s, and then reduce the pressure of the demineralized water to 8 Mpa and continue rinsing for 200 s. The three-stage rinsing with gradient pressure reduction generates a turbulent effect to remove the alkali liquid film layer. After rinsing, the conductivity ≤2 μS / cm, the sodium ion residue <0.05 ppb, and also can avoid the PN junction leakage current caused by Na+.

[0053] 104. The inner wall of the bell jar is pulse purged with clean hot air.

[0054] Wind is generated by a blower, filtered by an air filter, and then heated by a heater to form clean hot air at 65-80 °C with a cleanliness level of 100,000 and a dew point < -40 °C. The hot air is delivered into the bell jar for pulse purging. The pulse purging starts for 30 s and then closes for 15 s. The pulse purging time is 1800 s. And a vacuum is formed in the bell jar to increase the water evaporation rate by 3 times, and finally the humidity ≤1.5%, eliminating the uneven decomposition of silane caused by H2O adsorption.

[0055] Compared with the prior art, the present invention has the following technical effects:

[0056] First, by sequentially performing one-time high-pressure demineralized water spraying cleaning, NaOH solution spraying cleaning, and three-stage high-pressure demineralized water rinsing, the cleaning efficiency of the inner wall of the bell jar is significantly improved, the cleaning cycle is shortened, and at the same time, the resource cost and waste treatment cost of cleaning are reduced;

[0057] Second, through an effective cleaning method, the inner wall of the bell jar can be quickly cleaned, the product quality of polysilicon production is improved, and at the same time, the corrosion and damage of the equipment are reduced, and the service life of the equipment is extended;

[0058] Third, the inner wall of the bell jar is pulsed and purged with clean hot air, which can quickly dry the inner wall of the bell jar, thereby improving the drying efficiency.

[0059] Example 2

[0060] As Figure 1 and Figure 3 shown, the embodiment of the present invention provides another cleaning method for the bell jar of a polysilicon reduction furnace, and the method includes the following steps:

[0061] 201. Disassemble the bell jar from the reduction furnace, hoist it to the upper part of the placing component, and fix the bell jar.

[0062] 202. Continuously spray and clean the inner wall of the bell jar with high-pressure demineralized water.

[0063] 203. Circulatingly spray and clean the inner wall of the bell jar with a 5-15% NaOH solution.

[0064] 204. Perform three-stage rinsing on the inner wall of the bell jar with high-pressure demineralized water, and the pressure of the three-stage rinsing gradually decreases.

[0065] 205. Use laser-induced breakdown spectroscopy to on-line detect the element residues on the inner wall of the bell jar.

[0066] After the three-stage rinsing is completed, use laser-induced breakdown spectroscopy to detect the element residues on the inner wall of the bell jar.

[0067] 206. Pulse and purge the inner wall of the bell jar with clean hot air.

[0068] 207. Use a quartz crystal microbalance to real-time monitor the surface humidity.

[0069] After the pulse purge drying is completed, use a quartz crystal microbalance to real-time monitor the surface humidity.

[0070] Compared with the prior art, the present invention has the following technical effects:

[0071] First, by sequentially performing one-time high-pressure demineralized water spray cleaning, NaOH solution spray cleaning, and three-stage high-pressure demineralized water rinsing, the cleaning efficiency of the inner wall of the bell jar is significantly improved, the cleaning cycle is shortened, and at the same time, the resource cost and waste treatment cost of cleaning are reduced;

[0072] Second, through an effective cleaning method, the inner wall of the bell jar can be quickly cleaned, the product quality of polysilicon production is improved, and at the same time, the corrosion and damage of the equipment are reduced, and the service life of the equipment is extended;

[0073] Third, the inner wall of the bell jar is pulsed and purged with clean hot air, which can quickly dry the inner wall of the bell jar, thereby improving the drying efficiency.

[0074] Fourth, the element residues on the inner wall of the bell jar are detected by laser-induced breakdown spectroscopy, and the surface humidity is monitored in real time by a quartz crystal microbalance, so as to achieve the technical effect of improving the quality of polysilicon products.

[0075] On the other hand, as Figure 1 shown, an embodiment of the present invention further provides a cleaning device for a polysilicon reduction furnace bell jar, and the device includes:

[0076] A placement component 1 on which the bell jar 9 is placed;

[0077] A liquid supply component, which includes a spray head 21, a liquid supply pipeline 22, a water supply tank 23 and an alkali solution tank 24. The spray head 21 passes through and extends into the placement component 1. One end of the liquid supply pipeline 22 is connected to the spray head 21, and the other end is connected to the water supply tank 23 and the alkali solution tank 24;

[0078] A hot air component, which includes a blower 31, a filter 32, a heater 33 and an air outlet pipeline 34. One end of the air outlet pipeline 34 passes through and extends into the placement component 1, and the other end is sequentially connected to the heater 33, the filter 32 and the blower 31.

[0079] In the technical solution provided by the embodiment of the present invention, the function of the placement component 1 is to fix the bell jar 9, and the bell jar 9 is placed on the placement component 1. The function of the liquid supply component is to transport demineralized water and NaOH solution into the bell jar 9. The liquid supply component includes a spray head 21, a liquid supply pipeline 22, a water supply tank 23 and an alkali solution tank 24. The spray head 21 passes through and extends into the placement component 1. One end of the liquid supply pipeline 22 is connected to the spray head 21, and the other end is connected to the water supply tank 23 and the alkali solution tank 24; the function of the hot air component is to dry the inside of the bell jar 9. The hot air component includes a blower 31, a filter 32, a heater 33 and an air outlet pipeline 34. One end of the air outlet pipeline 34 passes through and extends into the placement component 1, and the other end is sequentially connected to the heater 33, the filter 32 and the blower 31. Compared with the prior art, the existing high-pressure water automatic cleaning system mainly performs multiple alternating flushes with water or weak alkali solution. Such a method has the following problems: the silicon powder remaining on the surface of the bell jar 9 is not completely removed, resulting in subsequent production pollution; during the alternating flushing process, a large amount of water resources and alkali solution are wasted; the alkaline cleaning solution will remain on the surface of the bell jar 9, resulting in equipment corrosion. In this technical solution, the demineralized water and NaOH solution can be respectively transported to the spray head 21 through the liquid supply pipeline 22, and the spray head 21 sprays the inner wall of the bell jar 9 to wash the inner wall of the bell jar 9, so as to achieve the technical effect of quickly cleaning the inner wall of the bell jar 9, and then hot air is transported into the bell jar 9 through the blower 31, so as to achieve the technical effect of quickly drying the inner wall of the bell jar 9.

[0080] The function of the placing component 1 is to fix the bell jar 9. The bell jar 9 is placed on the placing component 1. The upper part of the placing component 1 is used for installing the bell jar 9. The spray head 21 and the air outlet pipe 34 are installed on the bottom plate of the placing component 1. The function of the liquid supply component is to convey demineralized water and NaOH solution into the bell jar 9. The liquid supply component includes a spray head 21, a liquid supply pipe 22, a water supply tank 23 and an alkali solution tank 24. The spray head 21 passes through and extends into the placing component 1. One end of the liquid supply pipe 22 is connected to the spray head 21, and the other end is connected to the water supply tank 23 and the alkali solution tank 24. The water supply tank 23 and the alkali solution tank 24 are simultaneously connected to the liquid supply pipe 22. Moreover, a booster pump 5 and a plunger pump 6 are also installed on the liquid supply pipe 22 for conveying demineralized water and NaOH solution. The spray head 21 is installed at one end of the liquid supply pipe 22 and can spray demineralized water or NaOH solution on the inner wall of the bell jar 9. The function of the hot air component is to perform a drying treatment on the inside of the bell jar 9. The hot air component includes a blower 31, a filter 32, a heater 33 and an air outlet pipe 34. One end of the air outlet pipe 34 passes through and extends into the placing component 1, and the other end is sequentially connected to the heater 33, the filter 32 and the blower 31. The blower 31 conveys air into the air outlet pipe 34 through a pipeline. The filter 32 and the heater 33 are sequentially installed between the blower 31 and the air outlet pipe 34. The air is filtered by the filter 32 and then enters the heater 33 for heating to form hot air. The hot air is discharged through the air outlet pipe 34 to perform a drying treatment on the inner wall of the bell jar 9, which can not only effectively clean the inner wall of the bell jar 9, improve the cleaning cycle and the utilization rate of the equipment, but also improve the product quality of polysilicon.

[0081] Furthermore, there is a recovery component. The recovery component includes a discharge pipe 41, a waste liquid tank 42, a water treatment component 43 and a silicon powder recovery pool 44. One end of the discharge pipe 41 is connected to the placing component 1, and the other end is connected to the waste liquid tank 42. One end of the water treatment component 43 is connected to the waste liquid tank 42, and the other end is connected to the silicon powder recovery pool 44. In this embodiment, the recovery component is added. The function of the recovery component is to recycle the waste liquid after cleaning. One end of the discharge pipe 41 is installed at the bottom of the placing component 1 and can discharge the waste liquid after cleaning. The waste liquid tank 42 is connected to the discharge pipe 41 for collecting the waste liquid and separating the waste liquid. The separated wastewater enters the water treatment component 43 for treatment. The separated alkali solution returns to the alkali solution tank for continued use. The silicon powder separated by the water treatment component 43 returns to the silicon powder recovery pool 44, thereby achieving the technical effect of waste reuse.

[0082] Further, the recovery component further includes a clarifying tank 45, a waste liquid pipeline 46, and a waste liquid pump 47. The discharge pipeline 41 is connected to the clarifying tank 45. One end of the waste liquid pipeline 46 is connected to the clarifying tank 45, and the other end is connected to the water treatment component 43. The waste liquid pump 47 is arranged on the waste liquid pipeline 46. In this embodiment, the recovery component is further defined. The function of the clarifying tank 45 is to coagulate water and remove suspended substances and colloids in the water. One end of the waste liquid pipeline 46 is connected to the clarifying tank 45, and the other end is connected to the water treatment component 43. The water discharged from the clarifying tank 45 enters the water treatment component 43 for treatment, and the precipitated silicon powder enters the silicon powder recovery tank 44.

[0083] Further, the recovery component further includes a nitrogen pipeline 48 and a vent pipeline 49. The nitrogen pipeline 48 is connected to the lye tank and the waste liquid tank 42. The vent pipeline 49 is connected to the lye tank, the waste liquid tank 42, and the discharge pipeline 41. In this embodiment, the recovery component is further defined. One end of the nitrogen pipeline 48 is connected to the lye tank and the waste liquid tank 42, and the other end is connected to a nitrogen supply device. The nitrogen supply device transports nitrogen to the lye tank and the waste liquid tank 42 for displacing the gas in the lye tank and the waste liquid tank 42. The vent pipeline 49 is connected to the lye tank, the waste liquid tank 42, and the discharge pipeline 41 for discharging hydrogen or other harmless gases in the lye tank, the waste liquid tank 42, and the discharge pipeline 41.

[0084] Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general hardware. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that makes a contribution to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a floppy disk, hard disk, or optical disc of a computer, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments of the present invention.

[0085] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A cleaning method for the bell jar of a polysilicon reduction furnace, characterized in that, It includes the following steps: Continuously spray and clean the inner wall of the bell jar with high-pressure demineralized water; Circulatingly spray and clean the inner wall of the bell jar with 5-15% NaOH solution; Perform three-stage rinsing on the inner wall of the bell jar with high-pressure demineralized water, and the pressure of the three-stage rinsing gradually decreases; Pulse purge the inner wall of the bell jar with clean hot air.

2. The cleaning method according to claim 1, wherein The continuous spray cleaning of the inner wall of the bell jar with high-pressure demineralized water includes: Set the spray pressure of high-pressure demineralized water to 10-13 Mpa, the conductivity of demineralized water <0.1 μS / cm, and the spray time to 600 s; Transport the demineralized water to the cleaning nozzle through a booster pump, and the cleaning nozzle sprays and cleans the inner wall of the bell jar.

3. The cleaning method according to claim 1, characterized in that The spray pressure of the NaOH solution is 11-14 MPa, and the spray time is 800 s.

4. The cleaning method according to claim 1, characterized in that The pressures of the three-stage rinsing are 13 MPa, 10 MPa, and 8 MPa respectively.

5. The cleaning method according to claim 1, characterized in that The temperature of the clean hot air is 65-80 °C, the dew point temperature is less than -40 °C, and the purge time is 1800 s.

6. The cleaning method according to claim 5, characterized in that The on-off interval of the pulse purge is 30 s for purging / 15 s for disconnecting.

7. A cleaning system for the bell jar of a polysilicon reduction furnace, characterized in that, It includes: A placement component, on which the bell jar is placed; A liquid supply component, which includes a nozzle, a liquid supply pipeline, a water supply tank, and an alkali tank. The nozzle passes through and extends into the placement component, one end of the liquid supply pipeline is connected to the nozzle, and the other end is connected to the water supply tank and the alkali tank; A hot air component, which includes a blower, a filter, a heater, and an air outlet pipeline. One end of the air outlet pipeline passes through and extends into the placement component, and the other end is sequentially connected to the heater, the filter, and the blower.

8. A cleaning system for a bell cover of a polysilicon reduction furnace according to claim 7, characterized in that, It further includes: A recovery component, which includes a discharge pipeline, a waste liquid tank, a water treatment component, and a silicon powder recovery pool. One end of the discharge pipeline is connected to the placement component, and the other end is connected to the waste liquid tank. One end of the water treatment component is connected to the waste liquid tank, and the other end is connected to the silicon powder recovery pool.

9. The cleaning system for the bell jar of a polysilicon reduction furnace according to claim 8, characterized in that The recovery component further includes a clarification tank, a waste liquid pipeline, and a waste liquid pump. The discharge pipeline is connected to the clarification tank, one end of the waste liquid pipeline is connected to the clarification tank, and the other end is connected to the water treatment component. The waste liquid pump is arranged on the waste liquid pipeline.

10. The cleaning system for the bell jar of a polysilicon reduction furnace according to claim 9, characterized in that The recovery component further includes a nitrogen pipeline and a vent pipeline. The nitrogen pipeline is connected to the alkali tank and the waste liquid tank, and the vent pipeline is connected to the alkali tank, the waste liquid tank, and the discharge pipeline.

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