Multi-stage cleaning machine for recycling thick sheets of monocrystalline silicon

Abstract

The utility model discloses a multi-stage cleaning machine for recycling thick sheets of monocrystalline silicon. The multi-stage cleaning machine comprises a plurality of stages of rollers which are connected in series, a cleaning liquid storage tank and a liquid collecting tank, during liquid filling, each stage of roller is communicated with each cleaning liquid storage tank through a pipeline; and a rubber plug is inserted into the liquid inlet through hole of each stage of roller during cleaning. By means of the multiple stages of rollers connected in series and the multiple guide plates arranged on the inner walls of the rollers and used for recycling thick single crystal silicon sheets with the thickness ranging from 1 mm to 5 mm and the length and width ranging from 8 mm to 100 mm, the materials to be cleaned make full contact with cleaning liquid while rolling in the rollers, multi-stage cleaning is achieved, and meanwhile the problem that cleaning is not thorough due to the fact that the local portions make insufficient contact with the cleaning liquid can be solved.

Description

Technical Field

[0001] This application relates to the field of monocrystalline silicon recycling technology, and in particular to a multi-stage cleaning machine for recycling thick monocrystalline silicon wafers. Background Technology

[0002] Monocrystalline silicon is one of the most critical raw materials in the photovoltaic industry, primarily used in the manufacture of solar cells and related photovoltaic modules. Monocrystalline silicon is the core material for manufacturing high-efficiency solar cells, possessing the following characteristics: Monocrystalline silicon has a complete crystal structure and low impurity content, resulting in high photoelectric conversion efficiency, typically exceeding 20% ​​or even higher. This allows monocrystalline silicon solar cells to generate more electricity within the same area. Monocrystalline silicon also exhibits good stability and a long lifespan, generally exceeding 25 years. This makes monocrystalline silicon solar cells highly cost-effective over long-term use. Monocrystalline silicon solar cells are widely used in residential rooftop photovoltaic systems, large-scale ground-mounted power plants, and distributed photovoltaic power generation systems. For example, many residential rooftop photovoltaic systems utilize monocrystalline silicon solar cells.

[0003] During the production of monocrystalline silicon, whole blocks are often cut to meet processing needs, resulting in some recycled material. This recycled material is often contaminated and requires collection and cleaning before use. The difficulty of cleaning monocrystalline silicon varies depending on its size. For monocrystalline silicon wafers with a thickness of 1-5mm and a length and width of 8-100mm, known as thick monocrystalline silicon wafers, immersion cleaning is the primary method. The process of removing these wafers after immersion is labor-intensive, and when multi-stage cleaning is required, the operation is cumbersome and time-consuming, easily causing damage during transport and resulting in losses. Furthermore, the volatile gases produced by the cleaning solution during immersion cleaning pollute the environment and affect the health of cleaning personnel. Additionally, immersion cleaning can result in insufficient contact time between the recycled material and the cleaning solution, leading to incomplete cleaning and requiring reprocessing.

[0004] The information disclosed in the background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Utility Model Content

[0005] This application addresses the aforementioned technical problems by providing a multi-stage cleaning machine for recovering thick monocrystalline silicon wafers. This machine integrates multiple manual processes into a single operation, while simultaneously cleaning the recovered thick monocrystalline wafers thoroughly. This avoids the stacking issues that occur during manual cleaning, significantly improving production efficiency and reducing operational safety risks.

[0006] This application provides a multi-stage cleaning machine for recycling thick monocrystalline silicon wafers, including: multi-stage rollers connected in series, cleaning fluid storage tanks, and liquid collection tanks; during liquid filling, the water inlet pipes of each stage roller are respectively connected to the pipelines of each cleaning fluid storage tank;

[0007] The liquid collection tank is located below each stage of the rollers;

[0008] Multiple sets of pusher guide plates are installed on the inner wall of the drum: the pusher guide plates in each set are spaced apart along an oblique line; pusher spiral plates are symmetrically arranged in pairs inside the discharge opening of the drum.

[0009] Preferably, the rollers include: a first-stage roller, a second-stage roller, a third-stage roller, and a fourth-stage roller; the discharge opening of the first-stage roller is connected to the feed opening of the second-stage roller; the discharge opening of the second-stage roller is connected to the feed opening of the third-stage roller; and the discharge opening of the third-stage roller is connected to the feed opening of the fourth-stage roller.

[0010] Preferably, the cleaning fluid storage tank includes: an alkaline cleaning fluid storage tank, an acid cleaning fluid storage tank, a clean water storage tank, and a nozzle; the nozzle is positioned directly opposite the feed opening of the first-stage roller and is connected to the pipeline of the alkaline cleaning fluid storage tank;

[0011] The clear water storage tank is connected to the inlet pipes of the second-stage and fourth-stage rollers;

[0012] The pickling solution storage tank is connected to the water inlet pipe of the third-stage roller.

[0013] Preferably, it includes: a mesh connecting cylinder; a first-stage roller and a second-stage roller connected in series via the mesh connecting cylinder; a second-stage roller and a third-stage roller connected in series via the mesh connecting cylinder; and a third-stage roller and a fourth-stage roller connected in series via the mesh connecting cylinder.

[0014] Preferably, it includes: multiple delivery pumps and multiple valves; delivery pumps and valves are installed on the pipeline connecting the nozzle to the alkaline washing solution storage tank; delivery pumps and valves are installed on the pipeline connecting the acid washing solution storage tank to the third-stage roller; delivery pumps and valves are installed on the pipeline connecting the clean water storage tank to the second-stage roller and the fourth-stage roller.

[0015] Preferably, it includes: an air extraction pipe; the air extraction pipe is disposed outside the feed opening of the roller.

[0016] Preferably, it includes: a storage basket; the storage basket is disposed outside the discharge opening of the final stage roller.

[0017] Preferably, it includes: a support; a roller mounted on the support; and the support spanning across the liquid collection tank.

[0018] Preferably, it includes: a rack, a motor, a rotating shaft, and a drive gear; the rack is disposed on the outer wall of the drum; the motor is driven and connected to the rotating shaft; the drive gear is sleeved on the rotating shaft and driven and connected to the rack.

[0019] The beneficial effects that this application can produce include:

[0020] 1) The multi-stage cleaning machine for recycling thick monocrystalline silicon sheets provided in this application uses multi-stage drums connected in series. The thick monocrystalline silicon sheets to be cleaned are 1-5mm thick and 8-100mm long and wide. Multiple guide plates are set on the inner wall of the drums. While the material to be cleaned rolls in the drum, it comes into full contact with the cleaning liquid, thus achieving multi-stage cleaning. At the same time, it can avoid the problem of incomplete cleaning caused by insufficient contact with the cleaning liquid in some areas.

[0021] 2) The multi-stage cleaning machine for recycling thick monocrystalline silicon wafers provided in this application removes the waste gas generated by the evaporation of the cleaning liquid by setting an exhaust pipe at the discharge port for unified waste gas treatment, thereby reducing investment costs and maintaining the production environment. Attached Figure Description

[0022] Figure 1 A schematic diagram of the main structure of a multi-stage cleaning machine for recycling thick sheets of monocrystalline silicon in at least one embodiment provided in this application;

[0023] Figure 2 A schematic diagram of the cleaning tank end view in at least one embodiment provided in this application;

[0024] Figure 3 A schematic diagram of the unfolded state of the inner wall of the cleaning tank in at least one embodiment provided in this application;

[0025] Legend:

[0026] Alkaline washing solution storage tank 1, conveying pump 11, valve 111, air extraction pipe 2, acid washing solution storage tank 151, clean water storage tank 152, nozzle 112, feed opening 113, discharge opening 114, support 115, roller 12, rack 121, motor 3, support roller 124, rotating shaft 123, mesh connecting cylinder 141, storage basket 211, opening 123, pusher guide plate 124, pusher spiral plate 122, liquid collection tank 13. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] Technical means not detailed in this application and not used to solve the technical problems of this application are all set according to common general knowledge in the field, and multiple common general knowledge setting methods can be implemented.

[0030] See Figures 1-3 The multi-stage cleaning machine for recycling thick monocrystalline silicon wafers provided in this application includes: multiple rollers 12, an alkaline washing solution storage tank 1, a nozzle 112, a conveying pump 11, a valve 111, and an extraction pipe 2; the multiple rollers 12 are arranged in series, and the discharge port of the upper roller 12 is connected to the feed port of the lower roller 12; the nozzle 112 is located outside the feed opening 113 of the first-stage roller 12 and sprays towards the feed opening 113; the nozzle 112 is connected to the alkaline washing solution storage tank 1 by a pipeline, and the conveying pump 11 and the valve 111 are arranged at intervals on the connected pipeline; the extraction pipe 2 is located outside the feed opening 113 of the first-stage roller 12 and is used to extract the odor overflowing from the feed opening 113 for unified treatment.

[0031] This device is used to clean monocrystalline silicon recycled thick sheets with a thickness of 1-5mm and a length and width of 8-100mm. These recycled materials are the scraps generated after cutting during the production process. The surface is relatively clean, but various impurities inevitably adhere to it during processing. This device uses a sodium hydroxide solution with a mass concentration of 10-20% as the alkaline washing solution for alkaline washing. During the alkaline washing process, the material undergoes multi-stage cleaning as the drum 12 rotates, which improves the cleaning efficiency while ensuring the reliability of the surface cleaning effect and avoiding situations where some areas cannot be cleaned.

[0032] The rotation synchronization between the multi-stage rollers 12 can be achieved by adjusting the motors 3 at each stage.

[0033] In one specific embodiment, the system includes: a first-stage roller, a second-stage roller, a third-stage roller, and a fourth-stage roller; a nozzle 112 is provided on the feed inlet of the first-stage roller; the discharge outlet of the first-stage roller is connected to the second-stage roller; the discharge outlet of the second-stage roller is connected to the feed inlet of the third-stage roller; and the discharge opening 114 of the third-stage roller is connected to the feed opening 113 of the fourth-stage roller. This four-stage cleaning system ensures both cleaning effectiveness and efficiency.

[0034] In one specific embodiment, the system includes: a pickling solution storage tank 151 and a clean water storage tank 152; a nozzle 112 connected to the first-stage roller and the alkaline washing solution storage tank 1 via a pipeline; water inlet pipes are respectively installed on the feed ends of the second-stage roller and the fourth-stage roller. When clean water needs to be introduced for cleaning, the water inlet pipe is connected to the clean water storage tank 152 via a pipeline. A delivery pump 11 and a valve 111 are installed on the connecting pipeline. After the cleaning water is introduced into the roller 12, the pipeline is disconnected and the valve is closed for rolling cleaning; a water inlet pipe is installed on the feed end of the third-stage roller. When pickling solution needs to be introduced, the water inlet pipe is connected to the pickling solution storage tank 151 via a pipeline. A delivery pump 11 and a valve 111 are installed on the connecting pipeline. After the pickling solution is introduced into the roller 12, the pipeline is disconnected and the valve is closed for rolling cleaning.

[0035] After the cleaning solution is added at each stage, disconnect the inlet pipe from the cleaning solution storage tank, close the valve on the inlet pipe, and then the rollers 12 at each stage will rotate for cleaning. This setup allows for a comprehensive cleaning of the recovered materials through an alkaline wash, a water wash, an acid wash, and another water wash. The through-holes are connected to each storage tank via flexible hoses. After adding the solution, seal each through-hole with rubber stoppers 131. Alkaline washing removes a layer of the silicon material's outer layer, followed by acid-base neutralization and water washing.

[0036] In one specific embodiment, the connected rollers 12 are connected by a mesh connecting cylinder 141. When the material passes through the mesh connecting cylinder 141, the alkaline washing solution is discharged through the mesh, preventing the washing solution in different rollers 12 from contaminating the washing alkaline solution in the next stage roller 12.

[0037] In one specific embodiment, a through hole is provided on the side wall of the roller 12; a rubber plug 131 is inserted into the through hole; the through hole is connected to the pipeline of the alkaline washing solution storage tank 1. According to the cleaning needs, after liquid is fed into each roller 12 before feeding, the through hole is sealed by the rubber plug 131, and cleaning is carried out step by step to ensure the cleanliness of the alkaline solution used for each cleaning stage, avoid contamination, and improve cleaning efficiency.

[0038] In one specific embodiment, the system includes: a collection tank 13 and a support 115; each roller 12 is rotatably mounted on the support 115; the collection tank 13 is located directly opposite the support and below the rollers 12. The collection tank 13 allows for the recycling of wastewater from each cleaning stage.

[0039] The roller 12 has the same structure as the existing roller. Other structures not described in detail are set according to the existing structure. In a specific embodiment, it includes: rack 121, motor 3, support roller 124, and rotating shaft 123. The two ends of the rotating shaft 123 are respectively symmetrically arranged with support roller 124 and drive gear. The outer wall of the roller 12 is symmetrically arranged with rack 121 in pairs. The rack 121 meshes with the drive gear. The motor 3 is driven to one end of the rotating shaft 123. The motor 3 drives the support roller 124 and drive gear to rotate through the rotating shaft 123, thereby driving the rack 121 to drive the roller 12 to rotate.

[0040] In one specific embodiment, the roller 12 is made of polytetrafluoroethylene (PTFE). Using this material protects the monocrystalline silicon wafers being cleaned, reduces the impact force generated during tumbling cleaning, and protects the material from damage.

[0041] In one specific embodiment, a discharge opening 114 is provided on the discharge end of the drum 12; symmetrically arranged pushing spiral plates 122 are arranged inside the drum 12 near the discharge opening 114; multiple sets of pushing guide plates 124 are arranged on the inner wall of the drum 12; the pushing guide plates 124 within a set are arranged at intervals along an oblique line on the inner wall of the drum 12; the pushing guide plates 124 between sets are arranged at intervals. The pushing guide plates 124 are arranged in a spiral pattern, thereby realizing the directional pushing motion of the material inside the drum when the drum 12 rotates, while increasing the contact area between the material and the cleaning liquid, and pushing the material to tumble.

[0042] In one specific embodiment, it includes: a storage basket 211; the storage basket 211 is disposed outside the discharge opening 114 of the final stage roller 12 to realize the recycling of the cleaned material.

[0043] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-stage cleaning machine for single crystal silicon recovery ingot, characterized in that, It comprises: Multi-stage drum (12), cleaning liquid storage tank, liquid collecting tank (13); when filling liquid, the water inlet pipe of each stage drum (12) is respectively communicated with the pipeline of each cleaning liquid storage tank; The liquid collecting tank (13) is arranged below each stage drum (12); A plurality of groups of pushing guide plates (124) are arranged on the inner wall of the drum (12): the pushing guide plates (124) in a group are arranged along inclined lines at intervals; a pair of pushing spiral plates (122) are symmetrically arranged in the discharge opening (114) of the drum (12).

2. The multi-stage cleaning machine for single crystal silicon recovery slabs according to claim 1, wherein The drum (12) comprises: a first stage drum, a second stage drum, a third stage drum and a fourth stage drum; the discharge opening (114) of the first stage drum is communicated with the feeding opening (113) of the second stage drum; the discharge opening (114) of the second stage drum is communicated with the feeding opening (113) of the third stage drum; the discharge opening (114) of the third stage drum is communicated with the feeding opening (113) of the fourth stage drum.

3. The multi-stage cleaning machine for single crystal silicon recovery slabs according to claim 2, wherein The cleaning liquid storage tank comprises: an alkali cleaning liquid storage tank (1), an acid cleaning liquid storage tank (151), a clean water storage tank (152) and a spray head (112); The spray head (112) is arranged opposite to the feeding opening (113) of the first stage drum and is communicated with the pipeline of the alkali cleaning liquid storage tank (1); The clean water storage tank (152) is communicated with the water inlet pipe of the second stage drum and the fourth stage drum; The acid cleaning liquid storage tank (151) is communicated with the water inlet pipe of the third stage drum.

4. The multi-stage cleaning machine for single crystal silicon recovery ingot according to claim 2, wherein It comprises: A grid connecting cylinder (141); the first stage drum and the second stage drum are connected in series through the grid connecting cylinder (141); the second stage drum, the third stage drum are connected in series through the grid connecting cylinder (141); the third stage drum and the fourth stage drum are connected in series through the grid connecting cylinder (141).

5. The multi-stage cleaning machine for single crystal silicon recovery slabs according to claim 3, wherein It comprises: A plurality of conveying pumps (11) and a plurality of valves (111); the conveying pump (11) and the valve (111) are arranged on the pipeline communicated with the alkali cleaning liquid storage tank (1) of the spray head (112); The conveying pump (11) and the valve (111) are arranged on the pipeline communicated with the third stage drum of the acid cleaning liquid storage tank (151); The conveying pump (11) and the valve (111) are arranged on the pipeline communicated with the second stage drum and the fourth stage drum of the clean water storage tank (152).

6. The multi-stage cleaning machine for single crystal silicon recovery slabs according to claim 1, wherein It comprises: An air extraction pipe (2); the air extraction pipe (2) is arranged outside the feeding opening (113) of the drum (12).

7. The multi-stage cleaning machine for single crystal silicon recovery slabs according to claim 1, wherein It comprises: A storage basket (211); the storage basket (211) is arranged outside the discharge opening (114) of the last stage drum (12).

8. The multi-stage cleaning machine for single crystal silicon recovery slabs according to claim 1, wherein It comprises: A bracket (115); the drum (12) is mounted on the bracket (115); the bracket (115) is arranged on the liquid collecting tank (13).

9. The multi-stage cleaning machine for single crystal silicon recovery slabs according to claim 8, wherein It comprises: A rack (121), a motor (3), a rotating shaft (123) and a driving gear; the rack (121) is arranged on the outer wall of the drum (12); the motor (3) is drivingly connected with the rotating shaft (123); the driving gear is sleeved on the rotating shaft (123) and is drivingly connected with the rack (121).

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