Filter bag, filter device and filter system

Abstract

The utility model provides a filter bag, a filter device and a filter system. The filter bag is applied to the single crystal furnace and comprises a first bag body and a second bag body which are sequentially arranged in the first direction, the first bag body comprises at least one filter layer, and the second bag body comprises at least two filter layers. According to the filter bag, the second bag body comprises at least two filter layers, so that after gas enters the filter bag, at least part of the gas can be sequentially filtered through each filter layer of the second bag body, and the overall filtering performance of the filter bag is improved. Moreover, as the second bag body of the filter bag is provided with at least two filter layers, compared with a filter bag with a single filter layer on the whole, the filter bag disclosed by the utility model is higher in strength and not easy to damage in a long-term use process, so that the service life of the filter bag is prolonged.

Description

Technical Field

[0001] This application belongs to the field of gas filtration technology for single crystal furnaces, and in particular relates to a filter bag, a filtration device, and a filtration system. Background Technology

[0002] In the production of solar crystalline silicon, the requirements for oxygen, carbon, and volatile impurities in a negative pressure environment are extremely high. Argon is usually used as a protective gas. Argon is continuously introduced from the auxiliary chamber of the single crystal furnace and the furnace cylinder of the single crystal furnace according to certain process parameters. The argon circulates in the single crystal furnace, carrying away oxygen, carbon, and volatile impurities during the crystal pulling process, and is discharged from the exhaust port at the bottom of the furnace to ensure a stable crystal pulling environment and crystal pulling quality.

[0003] To establish a stable negative pressure environment and ensure the smooth discharge of oxygen, carbon, and volatile impurities generated during crystal pulling along the furnace bottom pipes, a filtration device is typically installed at the rear end of the exhaust port. However, existing filtration devices are prone to filter failure due to the influence of gas temperature during use, requiring frequent replacements. Utility Model Content

[0004] This application provides a filter bag, a filter device, and a filter system that, while ensuring the filtration effect of the filter bag, also improves the service life of the filter bag.

[0005] In a first aspect, this application provides a filter bag for use in a single crystal furnace and includes a first bag body and a second bag body arranged sequentially along a first direction, the first bag body including at least one filter layer and the second bag body including at least two filter layers.

[0006] In a second aspect, this application provides a filtration device applied to a single crystal furnace and comprising a tank and at least one filter bag as described above. The tank forms a sealed cavity and has an air inlet and an air outlet. The filter bag is fixedly disposed in the sealed cavity and communicates with the air inlet and the air outlet, with the first bag disposed near the air outlet and the second bag disposed near the air inlet.

[0007] In a third aspect, this application provides a filtration system comprising a single crystal furnace and the aforementioned filtration device, wherein the air inlet of the filtration device is connected to the single crystal furnace to filter the gas discharged from the single crystal furnace.

[0008] In summary, the filter bag, filter device, and filter system provided in this application have at least the following beneficial effects:

[0009] In this application, the filter bag includes a first bag body and a second bag body arranged sequentially along a first direction. Since the second bag body includes at least two filter layers, after gas enters the filter bag, at least a portion of the gas can be filtered sequentially through each filter layer of the second bag body 20, thereby improving the overall filtration performance of the filter bag. Furthermore, because the second bag body of the filter bag in this application has at least two filter layers, compared to a filter bag with a single filter layer, the filter bag in this application has higher strength and is less prone to damage during long-term use, thus extending the service life of the filter bag. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0011] Figure 1 This is a schematic diagram of the internal structure of the filtration system provided in an embodiment of this application;

[0012] Figure 2 This is a schematic diagram of the structure of the filter bag provided in the embodiments of this application;

[0013] Figure 3 This is a schematic diagram of a partial internal structure of a filter bag provided in an embodiment of this application;

[0014] Figure 4 This is a schematic diagram of the internal partial structure of another filter bag provided in an embodiment of this application.

[0015] The attached figures are labeled as follows:

[0016] 1000. Filtering device;

[0017] 100. Filter bag; 10. First bag body; 11. Third filter layer; 12. Fourth filter layer; 20. Second bag body; 21. First filter layer; 22. Second filter layer;

[0018] 200, Tank body; 210, Cylinder body; 220, Base; 230, Top cover; A1, Air inlet; A2, Air outlet; B1, Air inlet chamber; B2, Air outlet chamber;

[0019] 300. Fixing plate;

[0020] 400. Cleaning mechanism; 410. Mounting plate; 420. Movable plate; 430. Elastic element;

[0021] Z, First direction. Detailed Implementation

[0022] To make the above and other features and advantages of this application clearer, the present invention will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art and are exemplary only, not restrictive.

[0023] Furthermore, features specified with "first" or "second" for descriptive purposes only should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified with "first" or "second" may explicitly or implicitly include at least one of the specified features. The description of "multiple" generally means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] Figure 1 This is a schematic diagram of the internal structure of the filtration system provided in an embodiment of this application. Figure 2 This is a schematic diagram of the structure of the filter bag provided in an embodiment of this application.

[0025] Reference Figure 1 The filtration system in this embodiment includes a single crystal furnace (not shown) and a filtration device 1000. The filtration device 1000 is located at the rear end of the exhaust port of the single crystal furnace and is used to filter the gas discharged from the single crystal furnace so that the filtered gas can be reused.

[0026] The filtration device 1000 includes at least one filter bag 100 and a tank 200. The tank 200 forms a sealed cavity and has an air inlet A1 and an air outlet A2. The tank 200 is connected to a single crystal furnace through the air inlet A1, and the filter bag 100 is disposed in the sealed cavity of the tank 200 and is connected to the air inlet A1 and the air outlet A2.

[0027] When using the filter device 1000 for gas filtration, the gas inside the single crystal furnace can enter the tank 200 through the inlet A1, and the gas in the tank 200, after being filtered by the filter bag 100, can exit the filter device 1000 through the outlet A2. Furthermore, the outlet A2 of the filter device 1000 can also be connected to the inlet of the single crystal furnace, so that the gas filtered by the filter device 1000 can re-enter the single crystal furnace, thereby achieving gas recycling within the single crystal furnace.

[0028] Specifically, there can be multiple filter bags 100, which are spaced apart in the sealed cavity of the tank 200. Each filter bag 100 has a hollow tubular structure and a filter bag diameter of 100mm-120mm. After the gas enters the filter bag 100, it is filtered through the inner wall of the filter bag 100 and flows into the sealed cavity of the tank 200 and then flows out of the tank 200 through the gas outlet A2.

[0029] Reference Figure 1 and Figure 2 The filter bag 100 includes a first bag body 10 and a second bag body 20 arranged sequentially along a first direction Z. The first direction Z is the length direction of the filter bag 100. The first bag body 10 includes at least one filter layer, and the second bag body 20 includes at least two filter layers.

[0030] Specifically, the first bag 10 can be a single-layer filtration structure including only one filter layer, or a double-layer filtration structure including two filter layers, or a multi-layer filtration structure including two or more filter layers. This application does not make any specific limitations.

[0031] The second bag 20 can be a dual-layer filtration structure consisting of only two filter layers, or a multi-layer filtration structure consisting of two or more filter layers. This application does not make any specific limitation.

[0032] In this embodiment, the filter bag 100 includes a first bag body 10 and a second bag body 20 arranged sequentially along a first direction Z. Since the second bag body 20 includes at least two filter layers, after gas enters the filter bag 100, at least a portion of the gas can be filtered sequentially through each filter layer of the second bag body 20, thereby improving the overall filtration performance of the filter bag 100. Furthermore, because the second bag body 20 of the filter bag 100 has at least two filter layers, compared to a filter bag with a single filter layer, the filter bag 100 of this application has higher strength and is less prone to damage during long-term use, thus improving the service life of the filter bag 100.

[0033] Currently, with the continuous development of the photovoltaic industry and the constant upgrading of crystal pulling technology, new products have more stringent requirements for reducing oxygen, carbon, and volatile impurities during the crystal pulling process. This necessitates the use of vacuum pumps with higher pumping speeds, leading to an increase in the amount of flammable impurities accumulated on the surface of the filter bag 100 in the filtration device 1000. Under high-flow-rate gas blowing, these impurities are exposed to high temperatures. However, since the second bag body 20 in this embodiment includes at least two filter layers, it effectively avoids burns from high-temperature flammable impurities and gases, thus eliminating the need for frequent replacement of the filter bag 100 and significantly reducing equipment costs. Furthermore, according to experimental statistics, after using the filter bag 100 of this application, the service life of the filter bag 100 can be increased by 2-3 times, from replacing it once every two furnaces to replacing it once every four to eight furnaces. This significantly reduces the operating costs of the filter bag 100 and the maintenance personnel costs associated with replacing it.

[0034] Additionally, it should be noted that, in order to avoid flammable impurities burning the filter bag, existing technologies typically employ a combination of a pre-filter with lower filtration accuracy and a filter device with higher filtration accuracy. The pre-filter is placed between the filter device and the single crystal furnace. The pre-filter filters the gas discharged from the single crystal furnace to remove some flammable impurities, while the filter device filters the gas discharged from the pre-filter.

[0035] Although the two-stage filtration method has higher filtration accuracy, it is more expensive and more difficult to implement on-site. In this application, the scheme of using a combination of the first bag body 10 and the second bag body 20 can completely replace the two-stage filtration scheme. Moreover, the filter bag 100 in this application has a longer service life and lower cost.

[0036] Understandably, since the high-temperature gas in the single crystal furnace enters from the inlet A1 of the tank 200, the gas temperature at the inlet A1 must be greater than the gas temperature at the outlet A2. Therefore, the second bag 20 is usually positioned close to the inlet A1 of the tank 200, and the first bag 10 is positioned close to the outlet A2 of the tank 200. This can effectively prevent the high-temperature gas from burning the first bag 10, thereby helping to extend the service life of the filter bag 100.

[0037] Figure 3 This is a schematic diagram of a partial internal structure of a filter bag provided in an embodiment of this application. Figure 4 This is a schematic diagram of the internal partial structure of another filter bag provided in an embodiment of this application.

[0038] Reference Figure 3 and Figure 4The second bag body 20 of the filter bag 100 includes a first filter layer 21 and a second filter layer 22 located inside the first filter layer 21, and the melting point of the second filter layer 22 is higher than that of the first filter layer 21.

[0039] Specifically, the first filter layer 21 of the second bag body 20 can be separately manufactured and then connected as one piece with the first bag body 10, or the first filter layer 21 of the second bag body 20 can be integrally formed with the first bag body 10. The second filter layer 22 of the second bag body 20 can be connected to the first filter layer 21 by sewing.

[0040] Understandably, since the melting point of the second filter layer 22 is higher than that of the first filter layer 21, under the same environment, the high temperature resistance of the second filter layer 22 is better than that of the first filter layer 21. That is, compared with the first filter layer 21, the second filter layer 22 can withstand higher temperatures.

[0041] Therefore, in this embodiment, since the second bag body 20 is a double-layer filtration structure composed of the first filter layer 21 and the second filter layer 22, and the melting point of the second filter layer 22 located inside the first filter layer 21 is set to be higher than the melting point of the first filter layer 21, the second filter layer 22 can withstand a higher temperature than the first filter layer 21. Thus, after the gas enters the filter bag 100, the second filter layer 22 can prevent the high-temperature gas from burning the second bag body 20, and the second filter layer 22 can also perform a primary filtration of the gas containing volatile impurities. The gas filtered by the second filter layer 22 will be filtered a second time by the first filter layer 21. In this way, while ensuring the filtration performance of the second bag body 20, the service life of the second bag body 20 and the filter bag 100 as a whole is improved.

[0042] In some embodiments, the filtration accuracy of the first filter layer 21 of the second bag body 20 is greater than that of the second filter layer 22. This arrangement helps to improve the overall filtration performance of the filter bag 100 so that the cleanliness of the gas filtered through the second bag body 20 meets the process requirements.

[0043] In some embodiments, the filtration precision of the first filter layer 21 is 1μm-10μm, for example, it can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc. The filtration precision of the second filter layer 22 is 100μm-200μm, for example, it can be 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, etc.

[0044] Setting the filtration precision of the first filter layer 21 within the aforementioned range ensures that the outer layer of the second bag 20 possesses high filtration performance, thereby improving the cleanliness of the gas filtered through the second bag 20. Similarly, setting the filtration precision of the second filter layer 22 within the aforementioned range ensures that the inner layer of the second bag 20 possesses good high-temperature resistance while also maintaining a certain level of filtration performance. Therefore, based on the cooperation between the inner second filter layer 22 and the outer first filter layer 21, the overall filtration precision of the filter bag 100 can be guaranteed while effectively preventing high-temperature gases from scorching the filter bag 100, thus extending the overall service life of the filter bag 100 without requiring frequent replacements. This significantly reduces the operating costs of the filter bag 100 and the maintenance costs associated with replacing it.

[0045] In some embodiments, in order to ensure that the first filter layer 21 has a high filtration accuracy, the material of the first filter layer 21 includes polyester needle-punched felt, high silica, aramid cloth, etc.

[0046] In some embodiments, the material of the second filter layer 22 includes polyester needle-punched felt, high-silica, polyphenylene sulfide, polytetrafluoroethylene, glass fiber needle-punched felt, etc. Because polyphenylene sulfide is added to the material of the second filter layer 22, its high-temperature resistance is significantly improved, allowing the second filter layer 22 to withstand high-temperature gases up to 400°C without being burned.

[0047] In some embodiments, the length of the first bag body 10 along the first direction Z is greater than the length of the second bag body 20 along the first direction Z. Since the manufacturing cost of the second bag body 20 is higher than that of the first bag body 10, setting the length of the first bag body 10 to be greater than the length of the second bag body 20 helps to reduce the overall manufacturing cost of the filter bag 100.

[0048] Based on existing crystal pulling processes, it has been found that the distance of 200mm-500mm from the air inlet A1 of the tank 200 is a key factor limiting the improvement of the crystal pulling process and the development of the industry. Therefore, this application sets the length of the second bag 20 along the first direction Z to 200mm-500mm, while the length of the first bag 10 along the first direction Z can be adjusted according to actual needs, thereby maximizing the reduction of the overall manufacturing cost of the filter bag 100.

[0049] Optionally, the length of the first bag body 10 along the first direction Z can be set to 1700mm-2600mm. In this case, a second bag body 20 of appropriate length can be selected based on the length of the first bag body 10 and actual needs.

[0050] Reference Figure 3 and Figure 4The inner surface of the first bag 10 is flush with the inner surface of the second bag 20. "Flush" here means that the inner diameter of the first bag 10, formed by the inner surfaces of the first bag 10, is the same as the inner diameter of the second bag 20, formed by the inner surfaces of the second bag 20. In other words, the inner surfaces of the first bag 10 and the second bag 20 are coplanar.

[0051] This application sets the inner surface of the first bag body 10 and the inner surface of the second bag body 20 flush, which can avoid the impact on the filtration performance of the filter bag 100 caused by the accumulation of impurities inside the filter bag 100 at the connection between the second bag body 20 and the first bag body 10. This is because if the inner surface of the first bag body 10 and the inner surface of the second bag body 20 are not flush, a step will be formed at the connection, and the step will cause impurities inside the filter bag 100 to accumulate at this location, which will affect the filtration performance of the filter bag 100 after long-term use.

[0052] Continue to refer to Figure 3 The first bag body 10 of the filter bag 100 includes a third filter layer 11, which is connected to at least one of the first filter layer 21 and the second filter layer 22, and the filtration accuracy of the third filter layer 11 is greater than that of the second filter layer 22.

[0053] Specifically, one end of the third filter layer 11 in the first direction Z can be connected only to the first filter layer 21, or only to the second filter layer 22, or simultaneously to both the first filter layer 21 and the second filter layer 22. This application does not make any specific limitations.

[0054] Preferably, the structure and material of the third filter layer 11 can be the same as the first filter layer 21 of the second bag body 20. In this case, the filtration accuracy of the third filter layer 11 is the same as that of the first filter layer 21 of the second bag body 20. Furthermore, the third filter layer 11 can be integrally formed with the first filter layer 21 of the second bag body 20, or it can be separately formed and connected together.

[0055] In this embodiment, setting the filtration accuracy of the third filter layer 11 to be greater than that of the second filter layer 22 ensures that the cleanliness of the gas filtered by the first bag 10 meets the process requirements.

[0056] In some embodiments, the inner surface of the third filter layer 11 is flush with the inner surface of the second bag body 20. For example, when the second bag body 20 includes a first filter layer 21 and a second filter layer 22, the inner surface of the third filter layer 11 is flush with the inner surface of the second filter layer 22. Figure 3 As shown.

[0057] Here, "flush setting" means that the inner diameter of the first bag body 10 formed by the inner surface of the third filter layer 11 is the same as the inner diameter of the second bag body 20 formed by the inner surface of the second filter layer 22. In other words, the inner surface of the third filter layer 11 and the inner surface of the second filter layer 22 are coplanar.

[0058] When the inner surface of the third filter layer 11 is not flush with the inner surface of the second filter layer 22, a step will be formed at the connection point. This step will cause impurities to accumulate inside the filter bag 100, which will affect the filtration performance of the filter bag 100 over time. Therefore, this application sets the inner surface of the third filter layer 11 and the inner surface of the second filter layer 22 to be flush, which can avoid the impact on the filtration performance of the filter bag 100 caused by the accumulation of impurities inside the filter bag 100 at the connection point between the second bag body 20 and the first bag body 10.

[0059] Continue to refer to Figure 4 The first bag body 10 of the filter bag 100 includes a third filter layer 11 and a fourth filter layer 12, with the fourth filter layer 12 located inside the third filter layer 11. The melting point of the fourth filter layer 12 is higher than that of the third filter layer 11.

[0060] Understandably, since the melting point of the fourth filter layer 12 is higher than that of the third filter layer 11, under the same environment, the high temperature resistance of the fourth filter layer 12 is better than that of the third filter layer 11. That is, compared with the third filter layer 11, the fourth filter layer 12 can withstand higher temperatures.

[0061] Therefore, in this embodiment, since the first bag body 10 is a double-layer filtration structure composed of the third filter layer 11 and the fourth filter layer 12, and the melting point of the fourth filter layer 12 located inside the third filter layer 11 is set to be higher than the melting point of the third filter layer 11, the fourth filter layer 12 can withstand a higher temperature than the third filter layer 11. Thus, after the gas enters the filter bag 100, the fourth filter layer 12 can prevent the high-temperature gas from burning the first bag body 10, and the fourth filter layer 12 can also perform a primary filtration of the gas containing volatile impurities. The gas filtered by the fourth filter layer 12 will be filtered a second time by the third filter layer 11. In this way, while ensuring the filtration performance of the first bag body 10, the service life of the first bag body 10 and the filter bag 100 as a whole is improved.

[0062] Continue to refer to Figure 4 The first bag body 10 of the filter bag 100 includes a third filter layer 11 and a fourth filter layer 12, with the fourth filter layer 12 located inside the third filter layer 11. The filtration accuracy of the fourth filter layer 12 is less than or equal to the filtration accuracy of the third filter layer 11.

[0063] Specifically, when the filtration accuracy of the fourth filter layer 12 is less than that of the third filter layer 11, preferably, the structure and material of the fourth filter layer 12 can be the same as that of the second filter layer 22 of the second bag body 20. In this case, the filtration accuracy of the fourth filter layer 12 is the same as that of the second filter layer 22 of the second bag body 20. Furthermore, the fourth filter layer 12 can be integrally formed with the second filter layer 22 of the second bag body 20, or it can be separately formed and connected together. When the filtration accuracy of the fourth filter layer 12 is equal to that of the third filter layer 11, preferably, the structure and material of the fourth filter layer 12 can be the same as that of the third filter layer 11, and the fourth filter layer 12 can be integrally formed with the third filter layer 11, or it can be separately formed and connected together.

[0064] In this embodiment, setting the filtration accuracy of the fourth filter layer 12 to be less than or equal to the filtration accuracy of the third filter layer 11 can reduce the overall manufacturing cost of the first bag body 10 and the filter bag 100 while ensuring the filtration accuracy of the first bag body 10.

[0065] In some embodiments, the inner surface of the fourth filter layer 12 is flush with the inner surface of the second bag body 20. For example, when the second bag body 20 includes a first filter layer 21 and a second filter layer 22, the inner surface of the fourth filter layer 12 is flush with the inner surface of the second filter layer 22. Figure 4 As shown.

[0066] Here, "flush setting" means that the inner diameter of the first bag body 10 formed by the inner surface of the fourth filter layer 12 is the same as the inner diameter of the second bag body 20 formed by the inner surface of the second filter layer 22. In other words, the inner surface of the fourth filter layer 12 and the inner surface of the second filter layer 22 are coplanar.

[0067] When the inner surface of the fourth filter layer 12 is not flush with the inner surface of the second filter layer 22, a step will be formed at the connection point. This step will cause impurities to accumulate inside the filter bag 100, which will affect the filtration performance of the filter bag 100 over time. Therefore, this application sets the inner surface of the fourth filter layer 12 and the inner surface of the second filter layer 22 to be flush, which can avoid the impact on the filtration performance of the filter bag 100 caused by the accumulation of impurities inside the filter bag 100 at the connection point between the second bag body 20 and the first bag body 10.

[0068] In some embodiments, the filtration precision of the third filter layer 11 is 1μm-10μm, for example, it can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc. The filtration precision of the fourth filter layer 12 is 100μm-200μm, for example, it can be 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, etc.

[0069] Setting the filtration precision of the third filter layer 11 within the aforementioned range ensures that the outer layer of the first bag 10 possesses high filtration performance, thereby improving the cleanliness of the gas filtered through the first bag 10. Similarly, setting the filtration precision of the fourth filter layer 12 within the aforementioned range ensures that the inner layer of the first bag 10 possesses good high-temperature resistance while also maintaining a certain level of filtration performance. Therefore, the combination of the inner fourth filter layer 12 and the outer third filter layer 11 effectively prevents high-temperature gas from scorching the filter bag 100 while maintaining the overall filtration precision of the filter bag 100. This extends the overall service life of the filter bag 100, eliminating the need for frequent replacements and significantly reducing the operating costs and maintenance personnel costs associated with replacing the filter bag 100.

[0070] In some embodiments, in order to ensure that the third filter layer 11 has a high filtration accuracy, the material of the third filter layer 11 includes polyester needle-punched felt, high silica, aramid cloth, etc.

[0071] In some embodiments, the material of the fourth filter layer 12 includes polyester needle-punched felt, high-silica, polyphenylene sulfide, polytetrafluoroethylene, glass fiber needle-punched felt, etc. Because polyphenylene sulfide is added to the material of the fourth filter layer 12, its high-temperature resistance is significantly improved, allowing it to withstand high-temperature gases up to 400°C without being burned.

[0072] Continue to refer to Figure 1 The filter device 1000 in this embodiment of the application also includes a fixing plate 300 and a cleaning mechanism 400.

[0073] A fixing plate 300 is disposed within the sealed cavity of the tank 200 and connected to one end of the tank 200 near its air inlet A1. The second bag body 20 is fixedly disposed on the fixing plate 300. Specifically, the fixing plate 300 is provided with multiple through holes, and the second bag body 20 of the filter bag 100 is disposed in the through holes and fixed on the fixing plate 300 so that the interior of the filter bag 100 can communicate with the air inlet A1. Specifically, in the filter bag, the end of the second bag body 20 away from the first bag body 10 is provided with an opening; the opening of the second bag body 20 is located near the air inlet A1.

[0074] The cleaning mechanism 400 is disposed in the sealed cavity of the tank 200 and connected to the end of the tank 200 near its air outlet A2. The cleaning mechanism 400 is used to squeeze or release the filter bag 100 to clean the filter bag 100.

[0075] Based on the cleaning mechanism 400, impurities accumulated on the filter bag 100 can be cleaned regularly and in a timely manner, effectively preventing poor air permeability caused by impurities clogging the filter bag 100 due to prolonged use. Furthermore, the cleaning mechanism 400 cleans the filter bag 100 by squeezing or releasing it, a simple and efficient operation.

[0076] In some embodiments, refer to Figure 1 The cleaning mechanism 400 includes a mounting plate 410, a movable plate 420, an elastic element 430, and a driving element (not shown).

[0077] The mounting plate 410 is disposed between the first bag body 10 and the air outlet A2 along the first direction Z and is connected to the tank body 200. The movable plate 420 is disposed between the mounting plate 410 and the first bag body 10 along the first direction Z and is connected to the first bag body 10. The two ends of the elastic member 430 are respectively connected to the mounting plate 410 and the movable plate 420. The driving member is disposed on the mounting plate 410 and is used to apply force to the movable plate 420 or release the force on the movable plate 420 to squeeze or release the filter bag 100.

[0078] Specifically, the driving component can be a cylinder. The reciprocating motion of the movable plate 420 along the first direction Z can be achieved by extending and retracting the cylinder. For example, when the cylinder extends, it can push the movable plate 420 downward. When the cylinder retracts, the filter bag 100 quickly tightens. During the rapid tightening process, the filter bag 100 generates high-speed vibration to clean the dust.

[0079] In some embodiments, refer to Figure 1 The tank body 200 includes a cylindrical body 210, a base 220 and a top cover 230. The two ends of the cylindrical body 210 are connected to the base 220 and the top cover 230 respectively, and together they form a sealed cavity.

[0080] An air inlet A1 is provided on the base 220. The base 220 and the fixing plate 300 together form an air inlet chamber B1 that communicates with the air inlet A1. An air outlet A2 is provided on the top cover 230. The top cover 230 and the mounting plate 410 of the cleaning mechanism 400 together form an air outlet chamber B2 that communicates with the air outlet A2. The cavity between the fixing plate 300 and the mounting plate 410 communicates with the interior of the filter bag 100 through a small hole on the tube wall of the filter bag 100.

[0081] Specifically, when using the filter device 1000 for gas filtration, the gas in the single crystal furnace first enters the inlet chamber B1 through the inlet A1. The gas in the inlet chamber B1 enters the filter bag 100 through the opening of the filter bag and then flows out through the small holes on the pipe wall to the cavity between the fixed plate 300 and the mounting plate 410. Subsequently, it flows out of the tank 200 through the outlet chamber B2 and the outlet A2.

[0082] In order to adjust the position of the filter device 1000, the filter device 1000 also includes a caster assembly 500, which is mounted on the base 220 to support and drive the tank 200 to roll to move to the target usage position.

[0083] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A filter bag (100) characterized in that, Applied to a single crystal furnace, the filter bag (100) includes a first bag body (10) and a second bag body (20) arranged sequentially along a first direction (Z), the first bag body (10) including at least one filter layer, and the second bag body (20) including at least two filter layers; The second bag body (20) includes a first filter layer (21) and a second filter layer (22) located inside the first filter layer (21), and the melting point of the second filter layer (22) is higher than the melting point of the first filter layer (21).

2. The filter bag (100) according to claim 1, characterized in that The filtration accuracy of the first filter layer (21) is greater than that of the second filter layer (22).

3. The filter bag (100) according to claim 1, characterized in that, The filtration accuracy of the first filter layer (21) is 1μm-10μm; and / or The filtration accuracy of the second filter layer (22) is 100μm-200μm.

4. The filter bag (100) according to claim 1, characterized in that The length of the first bag (10) along the first direction (Z) is greater than the length of the second bag (20) along the first direction (Z).

5. The filter bag (100) according to claim 4, characterized in that, The length of the first bag body (10) along the first direction (Z) is 1700mm-2600mm; and / or The length of the second bag body (20) along the first direction (Z) is 200mm-500mm.

6. The filter bag (100) according to claim 1, characterized in that, The inner surface of the first bag (10) is flush with the inner surface of the second bag (20).

7. The filter bag (100) according to claim 1, characterized in that The first bag body (10) includes a third filter layer (11), which is connected to at least one of the first filter layer (21) and the second filter layer (22), and the filtration accuracy of the third filter layer (11) is greater than that of the second filter layer (22).

8. The filter bag (100) according to claim 7, characterized in that, The first bag body (10) further includes a fourth filter layer (12), which is located inside the third filter layer (11); Wherein, the melting point of the fourth filter layer (12) is higher than that of the third filter layer (11); and / or, the filtration accuracy of the fourth filter layer (12) is less than or equal to that of the third filter layer (11).

9. The filter bag (100) according to claim 8, characterized in that, The filtration accuracy of the third filter layer (11) is 1μm-10μm; and / or The filtration accuracy of the fourth filter layer (12) is 100μm-200μm.

10. A filtration device, characterized in that, Applied to a single crystal furnace, comprising a tank (200) and at least one filter bag (100) as described in any one of claims 1-9; the second bag (20) has an opening at one end away from the first bag (10); The tank (200) has a sealed cavity and an air inlet (A1) and an air outlet (A2). The filter bag (100) is fixedly disposed in the sealed cavity, and the first bag body (10) is disposed near the air outlet (A2), and the opening of the second bag body (20) is disposed near the air inlet (A1).

11. The filter device of claim 10, wherein, The filtration device further includes: A fixing plate (300) is disposed in the sealed cavity and connected to the end of the tank (200) near the air inlet (A1), and the second bag body (20) is fixedly disposed on the fixing plate (300); and a cleaning mechanism (400) is disposed in the sealed cavity and connected to the end of the tank (200) near the air outlet (A2), for squeezing or releasing the filter bag (100).

12. The filter device of claim 11, wherein, The cleaning mechanism (400) includes: An mounting plate (410) is disposed between the first bag body (10) and the air outlet (A2); the mounting plate (410) is connected to the tank body (200); An active plate (420) is disposed between the mounting plate (410) and the first bag body (10); the active plate (420) is connected to the first bag body (10); The elastic element (430) is connected at both ends to the mounting plate (410) and the movable plate (420); and A drive unit, disposed on the mounting plate (410), is used to apply force to the movable plate (420) or release the force on the movable plate (420) to squeeze or release the filter bag (100).

13. A filtration system characterized by, The invention includes a single crystal furnace and a filtration device as described in any one of claims 10-12, wherein the air inlet (A1) of the filtration device is connected to the single crystal furnace to filter the gas discharged from the single crystal furnace.

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