Device and method for removing light impurities from silicon crystal crushing scrap

Abstract

A device for removing light impurities from silicon crystal crushing scrap, the device comprising a vibration feeding device and an overflow cleaning device, wherein silicon crystal crushing scrap (13) is put in the overflow cleaning device by means of the vibration feeding device, and light impurities are removed from the silicon crystal crushing scrap by means of the overflow cleaning device. Further disclosed is a method for removing light impurities from silicon crystal crushing scrap. The method comprises the steps of vibration feeding and overflow cleaning. By means of the device and method for removing light impurities, automated removal of the light impurities from the silicon crystal crushing scrap is realized, thereby improving the impurity removal efficiency, and ensuring an impurity removal effect and the product quality; and the device has a simple structure, and is convenient to operate.

Description

Device and method for removing light impurities from silicon crystal foam

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 30, 2023, with application number 202310792400.X and application name “A device and method for removing light impurities from silicon crystal foam material”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the technical field of silicon material impurity removal, and in particular relates to a device and method for removing light impurities from silicon crystal foam material. Background Art

[0003] In the solar photovoltaic and semiconductor material manufacturing industries, silicon crystals, used as raw materials, are prone to producing 1-3 mm silicon crystal froth during grading and turnover. This silicon crystal froth requires impurity removal before use. Conventional cleaning is often used to remove light impurities, but this removal is difficult, resulting in unsatisfactory results and low efficiency, impacting product quality. Application Contents

[0004] The present application provides a device and method for removing light impurities from silicon crystal foam, aiming to solve the technical problem of low efficiency and unsatisfactory impurity removal effect of silicon crystal foam.

[0005] To solve at least one of the above technical problems, the technical solution adopted in this application is:

[0006] A device for removing light impurities from silicon crystal foam comprises: a vibration feeding device and an overflow cleaning device. The vibration feeding device places the silicon crystal foam in the overflow cleaning device, and the overflow cleaning device removes light impurities from the silicon crystal foam.

[0007] In some embodiments, the overflow cleaning device includes an overflow trough and a conveyor belt, one end of the conveyor belt is immersed in the overflow trough for receiving the silicon crystal foam material, and the other end is arranged outside the overflow trough to transport the silicon crystal foam material after light impurities are removed to the outside of the overflow trough.

[0008] In some embodiments, the conveyor belt is arranged at an angle, with the end arranged outside the overflow trough higher than the end immersed in the overflow trough, so that the portion of the conveyor belt located in the overflow trough is arranged above the liquid surface of the overflow trough.

[0009] In some embodiments, a first spray head and a second spray head are provided above the conveyor belt above the liquid level in the overflow tank, and are arranged in sequence along the conveying direction of the conveyor belt.

[0010] In some embodiments, a filter tank is provided on one side of the overflow tank for filtering light impurities to form circulating water to supply water to the first sprinkler head.

[0011] In some embodiments, a circulating water tank is provided on a side of the filter tank away from the overflow tank, and the circulating water tank is connected to the bottom of the filter tank and is used to store the circulating water to supply water to the first sprinkler head.

[0012] In some embodiments, the conveyor belt is provided with a discharge nozzle below one end outside the overflow trough, which is used to separate the silicon crystal foam material after impurities are removed from the conveyor belt.

[0013] A method for removing light impurities from silicon crystal foam material, using the above-mentioned silicon crystal foam material light impurity removal device, comprising the following steps:

[0014] Vibration feeding, using the vibration feeding device to feed the silicon crystal foam material;

[0015] Overflow cleaning: using the overflow cleaning device to remove light impurities from the silicon crystal foam material.

[0016] In some embodiments, the overflow cleaning includes overflow impurity removal, and the overflow cleaning device includes an overflow trough and a conveyor belt. One end of the conveyor belt is immersed in the overflow trough, and the other end is arranged outside the overflow trough. The end arranged outside the overflow trough is higher than the end immersed in the overflow trough, so that the part of the conveyor belt located in the overflow trough is arranged above the liquid level of the overflow trough. The vibrating loading device places the silicon crystal foam material on the end of the conveyor belt immersed in the overflow trough for impurity removal, and the conveyor belt moves the silicon crystal foam material after impurity removal out of the liquid level of the overflow trough.

[0017] In some embodiments, the overflow cleaning also includes spray flushing. A first spray head and a second spray head are provided in sequence above the conveyor belt above the liquid level in the overflow tank along the conveying direction of the conveyor belt. After the silicon crystal foam material completes the overflow impurity removal step, it is moved out of the liquid level of the overflow tank. The first spray head and the second spray head flush the silicon crystal foam material in sequence. Beneficial effects

[0018] By adopting the above technical solution, the light impurities in silicon crystal foam material are automatically removed, the impurity removal efficiency is improved, the impurity removal effect and product quality are guaranteed, the structure is simple and the operation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic diagram of the overall structure of a device for removing light impurities from silicon crystal foam material according to an embodiment of the present application;

[0020] FIG2 is a schematic diagram of the working process of a device for removing light impurities from silicon crystal foam material according to an embodiment of the present application;

[0021] Figure numerals: 1-overflow trough; 2-conveyor belt; 3-liquid level; 4-first spray head; 5-second spray head; 6-spacer bar; 7-filter trough; 8-filter screen; 9-circulating water trough; 10-feeding nozzle; 11-vibration motor; 12-feeding trough; 13-silicon crystal foam material. Implementation Methods of the Application

[0022] The embodiments of the present application provide a device and method for removing light impurities from silicon crystal foam material. The embodiments of the present application are described below with reference to the accompanying drawings.

[0023] In the description of the embodiments of the present application, it should be understood that the orientation or positional relationship indicated by the terms "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, it should be noted that, unless otherwise clearly stipulated and limited, the terms "setting" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a communication between the internal parts of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood based on specific circumstances.

[0024] As shown in FIG1 , an embodiment of the present application provides a device for removing light impurities from silicon crystal foam, comprising a vibrating feeding device and an overflow cleaning device. The vibrating feeding device places silicon crystal foam 13 in the overflow cleaning device, and the overflow cleaning device removes light impurities from the silicon crystal foam 13. The vibrating feeding device can evenly spread the silicon crystal foam 13 in the overflow cleaning device. The silicon crystal foam 13 enters the overflow cleaning device for cleaning. Due to its low density, the light impurities in the silicon crystal foam 13 float on the liquid surface 3 and overflow out of the overflow cleaning device with the water flow, thereby achieving the purpose of impurity removal.

[0025] The overflow cleaning device includes an overflow trough 1 and a conveyor belt 2, one end of the conveyor belt 2 is immersed in the overflow trough 1 for receiving silicon crystal foam 13, and the other end extends out of the overflow trough 1 and is arranged outside the overflow trough 1 to remove the silicon crystal foam 13 from the overflow trough 1. The vibrating feeding device evenly spreads the silicon crystal foam 13 on the end of the conveyor belt 2 immersed in the overflow trough 1. The light impurities float on the water surface due to their low density and overflow with the water flow. The conveyor belt 2 transfers the silicon crystal foam 13 after impurities removal to the outside of the overflow trough 1. The laying thickness of the silicon crystal foam 13 is not easy to be too large, which affects the overflow of light impurities. The optional laying thickness is 1mm to 2mm. Protrusions or baffles are provided on both sides of the conveyor belt 2, not shown in the figure, to prevent the silicon crystal foam 13 from falling into the overflow trough 1. The height of the protrusions or baffles can be determined according to the laying thickness, as long as it is greater than the laying thickness.

[0026] The conveyor belt 2 is tilted, with the end outside the overflow tank 1 being higher than the end immersed in the overflow tank 1, so that the portion of the conveyor belt 2 located in the overflow tank 1 is located above the liquid level 3 of the overflow tank 1, that is, the end of the conveyor belt 2 close to the vibrating feeding device is located below the liquid level 3, and the end away from the vibrating feeding device is tilted upward, so that the silicon crystal foam 13 after overflow and impurity removal gradually emerges from the water surface until it is transported to the outside of the overflow tank 1. Part of the conveyor belt 2 located in the overflow tank 1 is below the liquid level 3, and part of it is above the liquid level 3. In order to avoid contamination of the silicon crystal foam 13 after overflow and impurity removal, the length of the conveyor belt 2 below the liquid level 3 should not be too long, and can be selected not to exceed 1 meter. That is, after the vibrating feeding device places the silicon crystal foam 13 on the conveyor belt 2 for overflow and impurity removal, it is transported to above the liquid level 3 by the conveyor belt 2. The inclination angle of the conveyor belt 2 should not be too large, which will cause the silicon crystal foam material 13 to be unable to be spread flat on the conveyor belt 2, affecting the impurity removal effect. The inclination angle of the conveyor belt 2 is preferably 3° to 5°.

[0027] To further ensure effective impurity removal, a spray device can be installed above the conveyor belt 2, above the liquid level 3 of the overflow trough 1. This spray device removes impurities from the silicon crystal foam 13 after overflow impurity removal and rinses the silicon crystal foam 13. The spray device includes a first spray head 4 and a second spray head 5, which are arranged in sequence along the transmission direction of the conveyor belt 2. The water sprayed by the spray device further disperses the silicon crystal foam 13, flushing out light impurities trapped in the foam and allowing them to flow into the overflow trough and overflow with the water. By installing two stages of spray heads and rinsing multiple times, the cleanliness of the silicon crystal foam 13 is further ensured.

[0028] Since the conveyor belt 2 is arranged at an angle, in order to prevent the silicon crystal foam material 13 from sliding down and causing accumulation, which affects the impurity removal effect, spacer bars 6 are set on the conveyor belt 2 and are evenly arranged along the conveyor belt 2. The spacing between the spacer bars 6 is 200mm to 300mm, and the height of the spacer bars 6 can be set according to the thickness of the silicon crystal foam material 13, as long as it is greater than the laying thickness of the silicon crystal foam material 13, and the optional range is 3mm to 10mm.

[0029] A filter tank 7 is located on one side of overflow tank 1. Water overflowing from overflow tank 1 enters filter tank 7 for filtration. A filter screen 8 is installed at the top of filter tank 7 to filter out light impurities in the water. Circulating water forms below filter screen 8 and can be recycled. Filter screen 8 must be installed below the liquid level 3 in overflow tank 1. During use, ensure that the circulating water level 3 remains below the level of filter screen 8. Filter screen 8 can be made of nylon mesh with a pore size of 300 mesh or finer.

[0030] A circulating water tank 9 is provided on the side of the filter tank 7 away from the overflow tank 1. The circulating water tank 9 is connected to the bottom of the filter tank 7 and is used to store circulating water. The circulating water tank 9 is connected to the first spray head 4, that is, the first spray head 4 uses circulating water for spraying, and the second spray head 5 uses clean water for spraying, which not only ensures the spraying effect but also saves water resources.

[0031] In order to prevent the silicon crystal foam material 13 after light impurities are removed from adhering to the conveyor belt 2 and preventing unloading, a discharge nozzle 10 is provided below one end of the conveyor belt 2 outside the overflow trough 1 to separate the silicon crystal foam material 13 after impurities are removed from the conveyor belt 2. The discharge nozzle 10 is arranged on the outer wall of the overflow trough 1 at an angle upward, and separates the silicon crystal foam material 13 from the conveyor belt 2 by spraying water at an angle upward.

[0032] The vibrating feeding device is installed above the overflow cleaning device and includes a vibration motor 11 and a feeding trough 12. The vibration motor 11 is set at the bottom of the feeding trough 12. To facilitate feeding, the feeding trough 12 is tilted, with the end near the conveyor belt 2 lower than the other end. The vibration motor 11 causes the feeding trough 12 to vibrate, and the tilted feeding trough 12 spreads the silicon crystal foam 13 flat on the end of the conveyor belt 2 immersed in the overflow trough 1.

[0033] Example: A device for removing light impurities from silicon crystal foam, as shown in Figure 1, comprises an overflow trough 1, a conveyor belt 2, a first spray head 4, a second spray head 5, a filter trough 7, a circulating water trough 9, a discharge nozzle 10, a vibration motor 11, and a loading trough 12. The conveyor belt 2 is installed at an angle within the overflow trough 1, with one end immersed in the overflow trough 1 and the other end extending out of the overflow trough 1. The end outside the overflow trough 1 is higher than the end immersed in the overflow trough 1, so that the portion of the conveyor belt 2 within the overflow trough 1 is positioned above the liquid level 3 in the overflow trough 1. Part of the conveyor belt 2 within the overflow trough 1 is below the liquid level 3, while part is above it. The portion below the liquid level 3 is 500 mm long, and the conveyor belt 2 is tilted at a 3° angle. The first spray head 4 and the second spray head 5 are sequentially positioned along the conveyor belt 2's conveying direction, above the conveyor belt 2 above the liquid level 3 in the overflow trough 1. Spacers 6 are evenly spaced 250 mm apart on the conveyor belt 2. Baffles are provided on both sides of the conveyor belt 2, which are not shown in the figure. The height of the baffles and the spacer bars 6 is higher than the laying thickness of the silicon crystal foam material 13, which is 3 mm. A filter tank 7 is provided on one side of the overflow trough 1, and a 300-mesh nylon filter screen 8 is installed above the filter tank 7. A circulating water tank 9 is provided on the side of the filter tank 7 away from the overflow trough 1, which is connected to the bottom of the filter tank 7 and is used to supply water to the first sprinkler head 4. The discharge nozzle 10 is provided below the end of the conveyor belt 2 outside the overflow trough 1. The vibration motor 11 is provided at the bottom of the feeding trough 12, and the feeding trough 12 is provided at the end of the conveyor belt 2 immersed in the overflow trough 1. The feeding trough 12 is inclined, and the end close to the conveyor belt 2 is lower than the other end. The inclined feeding trough 12 spreads the silicon crystal foam material 13 flat on the end of the conveyor belt 2 immersed in the overflow trough 1.

[0034] A method for removing light impurities from silicon crystal foam material adopts the above-mentioned silicon crystal foam material 13 light impurity removal device, as shown in Figure 2, and the specific steps are: vibration loading, overflow impurity removal, spray flushing and water spraying unloading.

[0035] The vibration motor 11 drives the downward-inclined feeding trough 12 to vibrate, and the feeding trough 12 evenly spreads the silicon crystal foam material 13 in the overflow cleaning device. The overflow cleaning device performs overflow cleaning on the silicon crystal foam material 13. Light impurities float on the liquid surface 3 due to their low density and overflow the overflow cleaning device with the water flow.

[0036] Overflow cleaning includes overflow impurity removal. A loading trough 12 evenly deposits silicon crystal froth 13 onto the end of the conveyor belt 2 immersed in the overflow trough 1, with a thickness of 1 to 2 mm. After entering the overflow trough 1, light impurities float to the liquid surface 3 and overflow with the water flow. After impurity removal, the silicon crystal froth 13 is removed from the liquid surface 3 by the conveyor belt 2. The conveyor belt 2 operates at a speed of 0.2 to 1 m / s. Water overflowing from the overflow trough 1 enters the filter tank 7, where it is filtered through the filter screen 8 to form circulating water, which is stored in the circulating water tank 9.

[0037] Overflow cleaning also includes spraying and flushing impurities. After the conveyor belt 2 moves the silicon crystal foam material 13 after overflow impurity removal out of the liquid surface 3, the first spray head 4 uses the circulating water from the circulating water tank 9 to perform the first flushing and impurity removal on the silicon crystal foam material 13 on the conveyor belt 2. The second spray head 5 uses clean water to perform the second flushing and impurity removal. The silicon crystal foam material 13 is dispersed by the first spray head 4 and the second spray head 5, which is more conducive to flushing out the light impurities therein, and overflowing into the overflow tank 1 with the flushing water. During the flushing process, the spacer bars 6 set on the conveyor belt 2 can prevent the silicon crystal foam material 13 from sliding down, ensuring the flushing effect.

[0038] The silicon crystal foam material 13 after overflow cleaning is conveyed to the outside of the overflow tank 1 by the conveyor belt 2. In order to facilitate unloading, the unloading nozzle 10 is used to spray water obliquely upward to separate the silicon crystal foam material 13 after impurity removal from the conveyor belt 2.

[0039] The advantages and positive effects of this application are:

[0040] 1. It realizes the automatic removal of light impurities from silicon crystal foam, saves labor, improves the efficiency of impurity removal, has a simple structure and is easy to operate.

[0041] 2. Multiple impurities removal is carried out through overflow removal and spray flushing to ensure the impurity removal effect and product quality.

[0042] 3. The first sprinkler head uses circulating water for flushing, saving water resources.

[0043] 4. In the prior art, silicon crystal foam materials that are not thoroughly impurity-removed are mostly used for purification or sold directly and cannot be used for production. The silicon crystal foam materials after impurity removal using this technical solution can be used for the production of single crystals, reducing the production cost of single crystals.

[0044] The above embodiments of the present application are described in detail, but the contents are only preferred embodiments of the present application and cannot be considered to limit the scope of implementation of the present application. All equivalent changes and improvements made within the scope of the present application should still fall within the scope of the patent coverage of the present application.

Claims

1. A device for removing light impurities from silicon crystal foam, wherein: include: A vibration feeding device and an overflow cleaning device, wherein the vibration feeding device places silicon crystal foam material in the overflow cleaning device, and the overflow cleaning device removes light impurities from the silicon crystal foam material.

2. The device for removing light impurities from silicon crystal foam material according to claim 1, wherein: The overflow cleaning device includes an overflow trough and a conveyor belt. One end of the conveyor belt is immersed in the overflow trough and is configured to receive the silicon crystal foam material. The other end is arranged outside the overflow trough to transport the silicon crystal foam material after light impurities are removed to the outside of the overflow trough.

3. The device for removing light impurities from silicon crystal foam material according to claim 2, wherein: The conveyor belt is arranged obliquely, and one end of the conveyor belt arranged outside the overflow trough is higher than the end immersed in the overflow trough, so that the conveyor belt part located in the overflow trough is arranged above the liquid surface of the overflow trough.

4. The device for removing light impurities from silicon crystal foam material according to claim 3, wherein: A first spray head and a second spray head are arranged above the conveyor belt above the liquid level in the overflow tank, and the first spray head and the second spray head are arranged in sequence along the conveying direction of the conveyor belt.

5. The device for removing light impurities from silicon crystal foam material according to claim 4, wherein: A filter tank is provided on one side of the overflow tank, which is configured to filter light impurities to form circulating water to supply water to the first sprinkler head.

6. The device for removing light impurities from silicon crystal foam material according to claim 5, wherein: A circulating water tank is provided on one side of the filter tank away from the overflow tank. The circulating water tank is connected to the bottom of the filter tank and is configured to store the circulating water to supply water to the first spray head.

7. The device for removing light impurities from silicon crystal foam material according to any one of claims 2 to 6, wherein: The conveyor belt is provided with a feed nozzle below one end outside the overflow trough, and is configured to separate the silicon crystal foam material after impurities are removed from the conveyor belt.

8. A method for removing light impurities from silicon crystal foam material, wherein: The device for removing light impurities from silicon crystal foam material according to any one of claims 1 to 7 is used, and the method for removing light impurities from silicon crystal foam material comprises the following steps: Vibration feeding, using the vibration feeding device to feed the silicon crystal foam material; Overflow cleaning: using the overflow cleaning device to remove light impurities from the silicon crystal foam material.

9. The method for removing light impurities from silicon crystal foam material according to claim 8, wherein: The overflow cleaning includes overflow impurity removal. The overflow cleaning device includes an overflow trough and a conveyor belt. One end of the conveyor belt is immersed in the overflow trough, and the other end is arranged outside the overflow trough. The end arranged outside the overflow trough is higher than the end immersed in the overflow trough, so that the conveyor belt part located in the overflow trough is arranged above the liquid surface of the overflow trough. The vibrating feeding device places the silicon crystal foam material on the end of the conveyor belt immersed in the overflow trough for impurity removal, and the conveyor belt moves the silicon crystal foam material after impurity removal out of the liquid surface of the overflow trough.

10. The method for removing light impurities from silicon crystal foam material according to claim 9, wherein: The overflow cleaning also includes spray flushing. A first spray head and a second spray head are sequentially arranged above the conveyor belt above the liquid level in the overflow tank along the conveying direction of the conveyor belt. After the silicon crystal foam material completes the overflow impurity removal step, it moves out of the liquid level of the overflow tank. The first spray head and the second spray head sequentially flush the silicon crystal foam material.

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