Recycling system for machining wastewater and silicon powder of monocrystalline silicon square rod machine

Abstract

The invention provides a recycling system for machining wastewater and silicon powder of a monocrystalline silicon square rod machine. A raw water collecting tank of the recycling system is used for receiving wastewater from a drainage system; the aeration device is used for introducing gas into the raw water collecting tank so as to prevent silicon powder in the raw water from precipitating at the bottom of the raw water collecting tank; the filter press assembly is connected with the raw water collecting tank so as to carry out filter pressing on liquid from the raw water collecting tank to obtain silicon powder and filter pressing liquid; the silicon powder conveying mechanism is used for receiving the obtained silicon powder, conveying the silicon powder to a designated position and bagging and recycling the silicon powder; the filter is connected with the filter press assembly and is used for filtering press filtrate from the filter press assembly; the sterilizer is used for sterilizing the filtered liquid filtered by the filter; the recycling water tank is connected with the sterilizer and is used for receiving the filtered liquid sterilized by the sterilizer, and a liquid outlet of the recycling water tank is connected with a water inlet system of the monocrystalline silicon square rod processing equipment so as to provide machining water for the monocrystalline silicon square rod processing equipment.

Description

Technical Field

[0001] The present application relates to the technical field of single crystal silicon square rod processing, and in particular to a system for recycling wastewater and silicon powder from single crystal silicon square rod processing. Background Art

[0002] Monocrystalline silicon wafers are the basic material for making photovoltaic cell components. Their production method is to first obtain metallurgical grade industrial silicon from silicon ore through carbon reduction. The metallurgical grade industrial silicon is then used to produce high-purity trichlorosilane through cold hydrogenation and trichlorosilane synthesis equipment. Trichlorosilane and hydrogen are then passed into a high-temperature reduction furnace with a silicon core carrier pre-installed to obtain high-purity polycrystalline silicon. The polycrystalline silicon blocks are then loaded into the crucible of a single crystal furnace for melting. Through processes such as seeding, shouldering, and equalizing of single crystal seed crystals, they are finally drawn into monocrystalline silicon round rods of a certain diameter. The monocrystalline silicon round rods are then processed by cutting, squaring, grinding, and other machining processes to obtain raw material square rods for cutting photovoltaic silicon wafers. The square rods are then cut into photovoltaic silicon wafers of a certain thickness on an online cutting machine.

[0003] During the machining process of single-crystal round rods such as cutting and squaring, the cutting machines and squarers need to consume a large amount of water for cooling during the cutting process. Since the cooling water is in direct contact with the diamond wire for cutting and cooling, a large amount of ultra-fine silicon powder cut off is mixed in the cooling water, resulting in the cooling water being unable to be directly reused. In early production, people directly discharged the wastewater into the sedimentation tank. After the silicon powder was precipitated, the supernatant was discharged to the factory sewage treatment plant for treatment and discharge. The silicon powder in the sedimentation tank was regularly cleaned and transported out, resulting in a huge waste of silicon and water. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a system for recycling wastewater and silicon powder from single crystal silicon square rod machining.

[0005] The embodiment of the present application adopts the following technical solution: a system for recycling wastewater and silicon powder from single crystal silicon square rod machining, comprising:

[0006] A raw water collection tank, which is connected to the drainage system of the single crystal silicon square rod processing equipment and is used to receive wastewater from the drainage system;

[0007] an aeration device, which is arranged in the raw water collection tank and is used to introduce gas into the raw water collection tank to prevent silicon powder in the raw water from settling on the bottom of the raw water collection tank;

[0008] A filter press assembly connected to the raw water collection tank to filter the liquid from the raw water collection tank to obtain silicon powder and filtrate;

[0009] A silicon powder conveying mechanism is arranged below the filter press assembly and is used to receive the obtained silicon powder, convey the silicon powder to a designated location, and pack the silicon powder into bags for recovery;

[0010] a filter connected to the filter press assembly and used to filter the filtrate from the filter press assembly;

[0011] a sterilizer connected to the filter and used for sterilizing the filtered liquid after being filtered by the filter;

[0012] The recycling water pool has a liquid inlet connected to the sterilizer and is used to receive the filtered liquid after sterilization by the sterilizer. The liquid outlet of the recycling water pool is connected to the water inlet system of the single crystal silicon square rod processing equipment to provide machining water for the single crystal silicon square rod processing equipment.

[0013] In some embodiments, the aeration device includes an aeration pipe, which is arranged at the bottom of the raw water collection tank. The aeration pipe is provided with an exhaust hole, and the gas in the aeration pipe is discharged to the raw water collection tank through the exhaust hole to stir the raw water in the raw water collection tank.

[0014] In some embodiments, the recycling system further comprises a combustible gas alarm;

[0015] A combustible gas detector is provided on the raw water collection pool, and the combustible gas detector is connected to the combustible gas alarm; the combustible gas detector is used to detect the hydrogen content in the raw water collection pool and send the detection result to the combustible gas alarm.

[0016] In some embodiments, the recycling system further includes a dosing device, which is connected to the raw water collection tank and is used to add substances for adjusting the pH value of raw water in the raw water collection tank into the raw water collection tank.

[0017] In some embodiments, the recycling system further comprises a squeeze water tank and a compressed air storage tank, wherein the squeeze water tank and the compressed air storage tank are respectively connected to the filter press assembly to provide water and compressed air to the filter press assembly, respectively.

[0018] In some embodiments, the filter press assembly includes at least two filter presses, and the silicon powder conveying mechanism includes a single-machine conveying belt mechanism and a collecting conveying belt mechanism. The discharge end of the single-machine conveying belt mechanism is connected to the feed end of the collecting conveying belt mechanism to convey the silicon powder on the single-machine conveying belt mechanism to the collecting conveying belt mechanism. The discharge port end of the collecting conveying belt mechanism is connected to the feed port of the packaging mechanism to convey the silicon powder to the packaging mechanism for bagging.

[0019] In some embodiments, the recycling system further comprises a filtrate tank, a turbid liquid pipeline, and a clear liquid pipeline;

[0020] The filtrate tank is arranged on the pipeline between the filter press assembly and the filter;

[0021] One end of the turbid liquid pipeline is connected to the liquid outlet of the filter press assembly, and the other end of the turbid liquid pipeline is connected to the raw water collection tank to transport the turbid liquid filtered in the first stage of the filter press assembly back to the raw water collection tank;

[0022] One end of the clear liquid pipeline is connected to the liquid outlet of the filter press assembly, and the other end of the clear liquid pipeline is connected to the filtrate pool to transport the filtration clear liquid of the second stage of the filter press assembly to the filtrate pool; wherein the second stage is later than the first stage.

[0023] In some embodiments, a supply fan and an exhaust fan are respectively provided on the raw water collection pool, the filtrate pool and the reuse water pool. The supply fan is used to supply air to the raw water collection pool, the filtrate pool and the reuse water pool, and the exhaust fan is used to discharge the gas from the raw water collection pool, the filtrate pool and the reuse water pool to achieve ventilation of the raw water collection pool, the filtrate pool and the reuse water pool.

[0024] In some embodiments, an overflow pipe is also provided on the top of the filtrate tank, one end of the overflow pipe is connected to the filtrate tank, and the other end of the overflow pipe is connected to the factory sewage well.

[0025] In some embodiments, the raw water collection tank, the filtrate tank, and the recycled water tank are respectively equipped with a lifting assembly, and the lifting assembly includes a liquid level meter and a lifting pump, and the liquid level meter is interlocked with the lifting pump;

[0026] Each of the liquid level meters is used to detect the liquid levels of the raw water collection tank, the filtrate tank and the recycled water tank respectively;

[0027] When the liquid levels of the raw water collection tank, the filtrate tank and the recycled water tank are lower than the corresponding set liquid level heights, the lift pump stops pumping liquid.

[0028] The beneficial effects of the embodiments of the present application are:

[0029] The present application can realize the direct bagging and recycling of silicon powder obtained by filtration, and at the same time, the wastewater can be quickly circulated to the machining equipment for recycling after treatment. It has the advantages of simple process flow, stable equipment operation, convenient industrial application, and high recycling rate of silicon powder and wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0031] Figure 1 This is a schematic diagram of the structure of the system for recycling wastewater and silicon powder from processing of single crystal silicon square rods in this application;

[0032] Figure 2 This is a schematic diagram of the structure of the filter press assembly of this application.

[0033] Figure numerals: 1, processing equipment; 2, trench; 3, raw water collection tank; 4, aeration device; 5, first exhaust fan; 6, first air supply fan; 7, dosing device; 8, combustible gas detector; 9, first liquid level gauge; 10, first lifting pump; 11, filter press water inlet pipeline; 12, filter press; 13, squeeze water tank; 14, compressed air storage tank; 15, silicon powder conveying mechanism; 16, clear liquid pipeline; 17, turbid liquid pipeline; 18, filtrate tank ; 19. Second supply air fan; 20. Second exhaust air fan; 21. Second liquid level gauge; 22. Overflow pipeline; 23. Second lifting pump; 24. Replacement drainage pipeline; 25. Fine filtration pipeline; 26. Filter; 27. Fine filtration outlet pipeline; 28. Sterilizer; 29. ​​Recycled water pool; 30. Third supply air fan; 31. Third exhaust air fan; 32. Third liquid level gauge; 33. Water replenishment pipeline; 34. Third lifting pump; 35. Recycled water supply pipeline. DETAILED DESCRIPTION

[0034] Various aspects and features of the present application are described herein with reference to the accompanying drawings.

[0035] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present application will occur to those skilled in the art.

[0036] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0037] These and other characteristics of the present application will become apparent from the following description of a preferred form of embodiment given as a non-limiting example with reference to the accompanying drawings.

[0038] It should also be understood that although the present application has been described with reference to some specific examples, those skilled in the art will be able to readily implement many other equivalent forms of the present application.

[0039] The above and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings.

[0040] Specific embodiments of the present application are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments applied for are merely examples of the present application, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that obscure the present application. Therefore, the specific structural and functional details applied for herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present application in a variety of ways with substantially any suitable detailed structure.

[0041] This specification may use the phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present application.

[0042] In order to solve the problems in the background technology, the present application provides a system for recycling wastewater and silicon powder from processing of single crystal silicon square rods. The recycling system can be applied to single crystal silicon square rod processing equipment 1. Single crystal silicon square rod processing equipment 1 is used for processing square rods. When the square rod processing equipment 1 processes the square rods, its wastewater components are silicon powder and water. The square rod processing equipment 1 can be, but is not limited to, a cutting machine, a square opening machine, etc.

[0043] Combination Figure 1 The recycling system includes a raw water collection tank 3, an aeration device 4, a filter press 12 component, a silicon powder conveying mechanism 15, a filter 26, a sterilizer 28 and a reuse water tank 29.

[0044] The raw water collection tank 3 is connected to the drainage system of the single crystal silicon square rod processing equipment 1, and the drainage system includes wastewater generated when processing the square rods. The raw water collection tank 3 is used to receive wastewater from the drainage system. For example, the wastewater from the drainage system can flow into the raw water collection tank 3 through the ditch 2 or pipeline between the machining workshop and the raw water collection tank 3. Of course, the wastewater can also be pumped to the raw water collection tank 3 by a pumping pump.

[0045] The aeration device 4 is arranged in the raw water collection tank 3, and is used to introduce gas into the raw water collection tank 3. For example, the aeration device 4 can be arranged at the bottom of the raw water collection tank 3, and the liquid in the raw water collection tank 3 is stirred by the gas introduced into the raw water collection tank 3, so as to prevent the silicon powder in the raw water from settling on the bottom of the raw water collection tank 3. The aeration device 4 can be connected to an air source, and the air source is used to deliver a compressed gas of a certain pressure to the aeration device 4. After passing through the aeration device 4, the compressed gas is introduced into the raw water collection tank 3 at a certain pressure, thereby stirring the liquid in the raw water collection tank 3. The compressed gas can be an inert gas or compressed air, etc.

[0046] The filter press 12 component is connected to the raw water collection tank 3 to filter the liquid from the raw water collection tank 3 to obtain silicon powder and filtrate. The raw water in the raw water collection tank 3 can enter the filter press 12 component through the water inlet pipeline. Figure 2 The filter press 12 assembly may include one filter press 12, or may include more than two filter presses 12. More than two filter presses 12 may be arranged side by side. The filter press 12 may be, but is not limited to, a membrane filter press 12.

[0047] The silicon powder conveying mechanism 15 is arranged below the filter press 12 assembly, and is used to receive the silicon powder obtained by filtering the raw water by the filter press 12 assembly, and convey the silicon powder to a designated location, and bag the silicon powder for recycling. The bagged silicon powder can be sold without further processing, thereby improving the recycling rate of the silicon powder.

[0048] The filter 26 is connected to the filter press 12 assembly and is used to filter the filtrate from the filter press 12 assembly. Here, the filter 26 can be a precision filter 26, and the filter 26 can be, but not limited to, a bag structure, and the filtration accuracy can be set to 10 μm to 15 μm. The filter 26 can further filter the filtrate, so that the content of silicon powder in the obtained filtered liquid is reduced as much as possible, and can be reused.

[0049] The sterilizer 28 can be connected to the filter 26 through the fine filter outlet pipe 27 to sterilize the filtered liquid after being filtered by the filter 26. The sterilizer 28 can be, but is not limited to, ultraviolet sterilization to improve the cleanliness of the filtered liquid. Of course, it is understandable that the filtered liquid can also be sterilized in other ways according to actual production needs. This is only used as an example and does not constitute a limitation on the scope of protection of the claims.

[0050] The filtered liquid obtained after the above treatment process can meet the recycling standard, and the filtered liquid can be put into the machining equipment 1 again for utilization.

[0051] For example, the filtered liquid can be recycled after meeting the recycling standards shown in the table below.

[0052] Serial number index unit data 1 pH / 6-8 2 SS (amount of suspended solids) mg / L ≤40 3 Silica powder amount ‰ ≤1 4 Turbidity NTU ≤20

[0053] Of course, it is understandable that the above standards can be adjusted according to specific production requirements and do not constitute a limitation on the scope of protection of the claims.

[0054] The liquid inlet of the recycling pool 29 is connected to the sterilizer 28, and is used to receive the filtered liquid after sterilization by the sterilizer 28. The liquid outlet of the recycling pool 29 is connected to the water inlet system of the single crystal silicon square rod processing equipment 1 to provide machining water for the single crystal silicon square rod processing equipment 1, and the wastewater can be reused in real time while the silicon powder is recovered. Especially in large-scale projects, the rapid and continuous recycling of wastewater can be achieved.

[0055] The reuse water pool 29 may also be provided with a water replenishment pipeline 33 as required. The water replenishment pipeline 33 is used to replenish fresh water to the reuse water pool 29. Water replenishment and new water replacement operations may be performed according to water quality and system water loss.

[0056] This application can realize the direct bagging and recycling of silicon powder obtained by filter pressing, and the wastewater can be quickly circulated to the machining equipment for recycling after treatment. It has the advantages of simple process flow, stable equipment operation, convenient industrial application, high recycling rate of silicon powder and wastewater. The recycling system can achieve a silicon powder recovery rate of ≥99% in machining wastewater, a silicon powder moisture content of <40%, and a machining water recovery rate of ≥92%.

[0057] In some embodiments, the aeration device 4 includes an aeration pipe, which is arranged at the bottom of the raw water collection tank 3. The aeration pipe is provided with an exhaust hole, and the gas in the aeration pipe is discharged to the raw water collection tank 3 through the exhaust hole to stir the raw water in the raw water collection tank 3 and avoid the precipitation of silicon powder in the wastewater in the raw water collection tank 3. The aeration pipe can be evenly laid at the bottom of the raw water collection tank 3 to achieve uniform stirring of the liquid in the raw water collection tank 3. Of course, the aeration pipe can also be set at the side wall of the raw water collection tank 3 near the bottom of the raw water collection tank 3 as needed. The exhaust holes can be evenly set on the aeration pipe. When the aeration pipe is set at the bottom of the raw water collection tank 3, the exhaust holes can be set at the top of the aeration pipe to supply air to the liquid above the aeration pipe. When the aeration pipe is set on the side wall of the raw water collection tank 3, the exhaust holes can be set on the side of the aeration pipe facing the center of the raw water collection tank 3.

[0058] In some embodiments, the wastewater generated by machining contains cutting silicon powder, and a large amount of silicon powder and water will react slightly to generate a small amount of hydrogen. In order to prevent the accumulation and explosion of hydrogen, the raw water collection pool 3 can also be provided with a combustible gas detector 8, which can continuously monitor the hydrogen. The recycling system also includes a combustible gas alarm, and the combustible gas detector 8 is connected to the combustible gas alarm. The combustible gas detector 8 is used to detect the hydrogen content in the raw water collection pool 3 and send the detection results to the combustible gas alarm.

[0059] Specifically, the combustible gas detector 8 can send the detection result to the controller of the recycling system, or the controller of the machining equipment 1, or the controller of the combustible gas alarm. The controller can generate a control signal based on the received detection result, and then send the control signal to the combustible gas alarm. According to the controller, the received detection result can be compared with the preset combustible gas content. When the detection result is greater than the preset combustible gas content, the controller generates a control signal to control the combustible gas alarm to issue an alarm. After receiving the above control signal, the combustible gas alarm issues an alarm to remind the staff that the combustible gas exceeds the standard and take corresponding treatment measures.

[0060] In some embodiments, the recycling system further includes a dosing device 7 , which is connected to the raw water collection tank 3 and is used to add substances for adjusting the pH value of raw water in the raw water collection tank 3 into the raw water collection tank 3 .

[0061] The dosing device 7 can add citric acid into the raw water collection tank 3, and the citric acid can be used to adjust the pH value of the liquid in the raw water collection tank 3 to 6-8.

[0062] In some embodiments, the recycling system further includes a squeeze water tank 13 and a compressed air storage tank 14, which are respectively connected to the filter press 12 assembly to provide water and compressed air to the filter press 12 assembly. Continuing with the above embodiment, the filter press 12 can be a diaphragm filter press 12, a diaphragm water pressing + air blowing type filter press 12, so it is equipped with a squeeze water tank 13 and a compressed air storage tank 14 and corresponding pipelines, and the filter cloth can be selected with an air permeability of 50-60L / m2 / min. The moisture content of the silicon powder discharged from the mud reaches <40%, and can be directly bagged and sold.

[0063] In some embodiments, the filter press 12 assembly includes at least two filter presses 12, and the silicon powder conveying mechanism 15 includes a single conveying belt mechanism and a summary conveying belt mechanism. The discharge end of the single conveying belt mechanism is docked with the feed end of the summary conveying belt mechanism to convey the silicon powder on the single conveying belt mechanism to the summary conveying belt mechanism, and the discharge port end of the summary conveying belt mechanism is connected to the feed port of the packaging mechanism to convey the silicon powder to the packaging mechanism for bagging. That is, a single conveying belt mechanism is correspondingly arranged below each filter press 12, and the silicon powder obtained by filtration of each filter press 12 falls on the belt of the single conveying belt conveying mechanism corresponding to the filter press 12. Then, after aggregation, the silicon powder on the single conveying belt conveying mechanism can be converged to the summary conveying belt mechanism, and can be transported to the packaging mechanism for bagging via the belt of the summary conveying belt mechanism.

[0064] In some embodiments, the recycling system further includes a filtrate tank 18 , a turbid liquid pipeline 17 and a clear liquid pipeline 16 .

[0065] The filtrate pool 18 is arranged on the pipeline between the filter press 12 assembly and the filter 26, one end of the turbid liquid pipeline 17 is connected to the liquid outlet of the filter press 12 assembly, and the other end of the turbid liquid pipeline 17 is connected to the raw water collection pool 3, so as to transport the turbid liquid of the first stage of the filter press 12 assembly back to the raw water collection pool 3. That is, when the filter press 12 assembly starts to filter, the filtrate generated is relatively turbid, so the turbid liquid obtained by the early filtration can be transported back to the raw water collection pool 3.

[0066] One end of the clear liquid pipeline 16 is connected to the liquid outlet of the filter press 12 component, and the other end of the clear liquid pipeline 16 is connected to the filtrate pool 18 to transport the filtered clear liquid of the second stage of the filter press 12 component to the filtrate pool 18; wherein the second stage is later than the first stage. Here, the liquid outlet connected to the turbid liquid pipeline 17 can be a liquid outlet arranged at the bottom of the filter press 12 component, and the liquid outlet connected to the clear liquid pipeline 16 can be a liquid outlet arranged at the top of the filter press 12 component. Of course, the above-mentioned liquid outlets connected to the turbid liquid pipeline 17 and the clear liquid pipeline 16 can also be the same liquid outlet.

[0067] In the later stage of filtration by the filter press 12 assembly, the cleanliness of the filtrate obtained by filtration is improved, and the clear liquid can flow to the filtrate tank 18 through the clear liquid pipeline 16.

[0068] In some embodiments, a blower and an exhaust fan are respectively provided on the raw water collection pool 3, the filtrate pool 18 and the reuse water pool 29. The blower is used to supply air to the raw water collection pool 3, the filtrate pool 18 and the reuse water pool 29, and the exhaust fan is used to discharge the gas from the raw water collection pool 3, the filtrate pool 18 and the reuse water pool 29 to achieve ventilation of the raw water collection pool 3, the filtrate pool 18 and the reuse water pool 29. It is used to ensure air circulation in the pool to avoid water quality deterioration and fungus breeding.

[0069] Specific, combined Figure 1 A first air supply fan 6 and a first exhaust fan 5 may be provided on the raw water collection pool 3 , a second air supply fan 19 and a second exhaust fan 20 may be provided on the filtrate pool 18 , and a third air supply fan 30 and a third exhaust fan 31 may be provided on the recycled water pool 29 .

[0070] The supply and exhaust fans can be turned on and off manually, or they can be started and stopped in conjunction with the combustible gas alarm. Exhaust and supply fans should be explosion-proof.

[0071] In some embodiments, an overflow pipe 22 is also provided on the top of the filtrate tank 18, one end of the overflow pipe 22 is connected to the filtrate tank 18, and the other end of the overflow pipe 22 is connected to the factory sewage well. When there is too much liquid in the filtrate tank 18, the liquid in the filtrate tank 18 is discharged into the sewage well through the overflow pipe 22.

[0072] In some embodiments, the raw water collection tank 3, the filtrate tank 18 and the recycled water tank 29 are respectively equipped with lifting components, and the lifting components include a liquid level meter and a lifting pump, and the liquid level meter is interlocked with the lifting pump.

[0073] Each level meter is used to detect the liquid level of the raw water collection tank 3, the filtrate tank 18 and the recycled water tank 29 respectively.

[0074] When the liquid levels of the raw water collection tank 3, the filtrate tank 18 and the recycled water tank 29 are lower than the corresponding set liquid level heights, the lift pump stops pumping liquid.

[0075] For example, a first liquid level gauge 9 is provided in the raw water collection tank 3, and the first liquid level gauge is used to detect the liquid level height in the raw water collection tank 3. A first lifting pump 10 is provided on the filter press water inlet pipeline 11 between the raw water collection tank 3 and the filter press 12 assembly. A second liquid level gauge 21 is provided in the filtrate tank 18, and the second liquid level gauge 21 is used to detect the liquid level height in the filtrate tank 18. A second lifting pump 23 is provided on the fine filter pipeline 25 between the filtrate tank 18 and the filter 26. A displacement drainage pipeline 24 can also be provided between the fine filter pipeline 25 and the overflow pipeline 22. A third liquid level gauge 32 is provided in the reuse water tank 29, and the third liquid level gauge 32 is used to detect the height of the liquid level in the reuse water tank 29. A third lifting pump is provided on the reuse water supply pipeline 35 between the reuse water tank 29 and the machining equipment 1. Taking the raw water collection tank as an example, when the first liquid level meter 9 detects that the liquid level in the raw water collection tank 3 is less than the preset liquid level, the first lift pump 10 stops pumping liquid to the filter press 12 assembly to avoid emptying. Because the raw water contains silicon powder, the first lift pump 10 can use a professional wear-resistant slurry pump, and the second lift pump 23 and the third lift pump 34 can use ordinary water pumps, or professional wear-resistant slurry pumps can also be used.

[0076] Multiple embodiments of the present application are described in detail above, but the present application is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications to the embodiments based on the concept of the present application, and these variations and modifications should all fall within the scope of protection required by the present application.

Claims

1. A system for recycling wastewater and silicon powder from single crystal silicon square rod machining, characterized in that: include: A raw water collection tank, which is connected to the drainage system of the single crystal silicon square rod processing equipment and is used to receive wastewater from the drainage system; an aeration device, which is arranged in the raw water collection tank and is used to introduce gas into the raw water collection tank to prevent silicon powder in the raw water from settling on the bottom of the raw water collection tank; A filter press assembly connected to the raw water collection tank to filter the liquid from the raw water collection tank to obtain silicon powder and filtrate; A silicon powder conveying mechanism is arranged below the filter press assembly and is used to receive the obtained silicon powder, convey the silicon powder to a designated location, and pack the silicon powder into bags for recovery; a filter connected to the filter press assembly and used to filter the filtrate from the filter press assembly; a sterilizer connected to the filter and used for sterilizing the filtered liquid after being filtered by the filter; The recycling water pool has a liquid inlet connected to the sterilizer and is used to receive the filtered liquid after sterilization by the sterilizer. The liquid outlet of the recycling water pool is connected to the water inlet system of the single crystal silicon square rod processing equipment to provide machining water for the single crystal silicon square rod processing equipment.

2. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 1, characterized in that: The aeration device includes an aeration pipe, which is arranged at the bottom of the raw water collection tank. The aeration pipe is provided with an exhaust hole, and the gas in the aeration pipe is discharged to the raw water collection tank through the exhaust hole to stir the raw water in the raw water collection tank.

3. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 1, characterized in that: The recycling system also includes a combustible gas alarm; A combustible gas detector is provided on the raw water collection pool, and the combustible gas detector is connected to the combustible gas alarm; the combustible gas detector is used to detect the hydrogen content in the raw water collection pool and send the detection result to the combustible gas alarm.

4. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 1, characterized in that: The recycling system also includes a dosing device, which is connected to the raw water collection tank and is used to add substances used to adjust the pH value of raw water in the raw water collection tank into the raw water collection tank.

5. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 1, characterized in that: The recycling system further comprises a squeeze water tank and a compressed air storage tank, wherein the squeeze water tank and the compressed air storage tank are respectively connected to the filter press assembly to provide water and compressed air to the filter press assembly respectively.

6. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 1, characterized in that: The filter press assembly includes at least two filter presses, and the silicon powder conveying mechanism includes a single-machine conveying belt mechanism and a collective conveying belt mechanism. The discharge end of the single-machine conveying belt mechanism is connected to the feed end of the collective conveying belt mechanism to convey the silicon powder on the single-machine conveying belt mechanism to the collective conveying belt mechanism. The discharge port end of the collective conveying belt mechanism is connected to the feed port of the packaging mechanism to convey the silicon powder to the packaging mechanism for bagging.

7. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 1, characterized in that: The recycling system also includes a filtrate tank, a turbid liquid pipeline and a clear liquid pipeline; The filtrate tank is arranged on the pipeline between the filter press assembly and the filter; One end of the turbid liquid pipeline is connected to the liquid outlet of the filter press assembly, and the other end of the turbid liquid pipeline is connected to the raw water collection tank to transport the turbid liquid filtered in the first stage of the filter press assembly back to the raw water collection tank; One end of the clear liquid pipeline is connected to the liquid outlet of the filter press assembly, and the other end of the clear liquid pipeline is connected to the filtrate pool to transport the filtration clear liquid of the second stage of the filter press assembly to the filtrate pool; wherein the second stage is later than the first stage.

8. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 7, characterized in that: The raw water collection pool, the filtrate pool and the reuse water pool are respectively provided with a blower and an exhaust fan. The blower is used to supply air to the raw water collection pool, the filtrate pool and the reuse water pool, and the exhaust fan is used to discharge the gas from the raw water collection pool, the filtrate pool and the reuse water pool to achieve ventilation of the raw water collection pool, the filtrate pool and the reuse water pool.

9. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 7, characterized in that: An overflow pipeline is also arranged on the top of the filtrate pool, one end of the overflow pipeline is connected to the filtrate pool, and the other end of the overflow pipeline is connected to the factory sewage well.

10. The system for recycling wastewater and silicon powder from single crystal silicon square rod machining according to claim 7, characterized in that: The raw water collection tank, the filtrate tank and the recycled water tank are respectively provided with a lifting assembly, the lifting assembly comprises a liquid level gauge and a lifting pump, and the liquid level gauge is interlocked with the lifting pump; Each of the liquid level meters is used to detect the liquid levels of the raw water collection tank, the filtrate tank and the recycled water tank respectively; When the liquid levels of the raw water collection tank, the filtrate tank and the recycled water tank are lower than the corresponding set liquid level heights, the lift pump stops pumping liquid.

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