Photovoltaic fragment screening system, and method for separating glass panel and silicon wafer in photovoltaic module

Abstract

Disclosed in the present application are a photovoltaic fragment screening system, and a method for separating glass panels and silicon wafers in a photovoltaic module. The photovoltaic fragment screening system comprises a screen mesh, a vibration member, a material receiving tray and a control mechanism, the screen mesh being used for screening photovoltaic fragments, the vibration member being used for driving the screen mesh to vibrate, the material receiving tray being used for receiving the screened photovoltaic fragments, and the control mechanism comprising a weighing device and a vibration control device. The vibration control device is connected to the vibration member so as to control the vibration of the vibration member, and the weighing device is electrically connected to the vibration control device so as to send weight information of silicon wafer materials on the screen mesh to the vibration control device, such that the vibration control device controls the vibration of the vibration member according to the weight information of the silicon wafer materials. The photovoltaic fragment screening system provided by the present application has the advantages of high screening efficiency, thorough material separation and a high material recovery rate.

Description

Photovoltaic debris screening system and method for separating photovoltaic module glass plates and silicon wafers

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to a Chinese patent application filed with the Patent Office of China on March 25, 2024, with application number 202410345149.7 and invention name “A photovoltaic debris screening system and a method for separating photovoltaic module glass plates and silicon wafers”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of photovoltaic recycling technology, and in particular to a photovoltaic debris screening system and a method for separating photovoltaic module glass plates and silicon wafers. Background Art

[0004] Photovoltaic power generation is a key area of ​​new energy development. However, with the rapid growth of the photovoltaic power industry, the production of discarded photovoltaic modules has surged. Developing efficient disassembly and recycling technologies to completely separate the photovoltaic module's cells, glass, backsheet, and solder ribbons, as well as recover the crystalline silicon and various metal elements, has become a hot topic of research. The first step in recycling is the initial separation of the photovoltaic panel. In the photovoltaic panel structure, the solder ribbon, electrodes, and crystalline silicon can be considered as a single unit. However, this unit is sandwiched between the tempered glass through the encapsulation layer, making separation difficult.

[0005] Summary of the Invention

[0006] This application is based on the inventor's discovery and understanding of the following facts and problems: it is difficult to separate glass and crystalline silicon in photovoltaic recycling.

[0007] The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiments of the present application provide a photovoltaic debris screening system, which has the advantages of high screening efficiency, thorough material separation, and high material recovery rate.

[0008] According to the photovoltaic fragment screening system of the embodiment of the present application, the photovoltaic fragment screening system includes a screen, a vibrating member, a material receiving tray and a control mechanism, the screen is used to screen photovoltaic fragments, the vibrating member is used to drive the screen to vibrate, the material receiving tray is used to receive the photovoltaic fragments after screening, the control mechanism includes a weighing device and a vibration control device, the vibration control device is connected to the vibrating member to control the vibration of the vibrating member, the weighing device is electrically connected to the vibration control device to send the weight information of the silicon wafer material on the screen to the vibration control device, and the vibration control device controls the vibration of the vibrating member according to the weight information of the silicon wafer material.

[0009] The photovoltaic debris screening system according to the embodiment of the present application has the advantages of high screening efficiency, thorough material separation, and high material recovery rate.

[0010] In some embodiments, the vibration control device includes a data processor, the weighing device records the weight of the material receiving tray within a preset time period, the data processor obtains the falling speed of the silicon wafer based on the time and weight data, and the vibration control device controls the vibration of the vibrating member according to the falling speed of the silicon wafer.

[0011] In some embodiments, the screen is a unidirectional screen.

[0012] In some embodiments, the spacing of the screen is adjusted according to the equivalent diameter and thickness of the photovoltaic fragments to complete the separation of glass and silicon wafers.

[0013] In some embodiments, the mesh spacing is 0.2 mm to 1 mm.

[0014] According to the method for separating the glass plate and silicon wafer of a photovoltaic module according to an embodiment of the present application, the method for separating the glass plate and silicon wafer of a photovoltaic module comprises the following steps:

[0015] Firing photovoltaic panels within a preset temperature range;

[0016] Collecting the roasted material fragments;

[0017] A screening system is activated to screen the material fragments, wherein the screening system determines a vibration mode with the highest screening efficiency according to the falling speed of the silicon wafers;

[0018] The vibrating element maintains a vibration mode with maximum screening efficiency until screening is completed.

[0019] In some embodiments, after large-sized fragments and long welding strips are sorted out from the fired material fragments, the glass in the fired material fragments is broken into fragments with an equivalent diameter of 3 to 8 mm, and the silicon wafers are broken into irregular thin slices with a thickness of 0 to 0.2 mm.

[0020] In some embodiments, the weight value of the silicon wafer in the target time period is subtracted from the weight of the silicon wafer in the adjacent time period to obtain a weight difference, and the falling speed of the silicon wafer is the ratio of the weight difference to the time period.

[0021] In some embodiments, the screen maintains the same vibration mode during several time periods, and all vibration modes are traversed to obtain the vibration mode with the maximum falling speed of the silicon wafer, thereby obtaining the screening mode with the highest screening efficiency.

[0022] In some embodiments, the glass on the screen is discharged to a glass receiving tray after reaching a target weight.

[0023] The method and corresponding equipment described in this application are reliable in principle, simple to execute, and thoroughly separate the tempered glass, encapsulation layer, and silicon wafer layers, making them an effective measure in the photovoltaic panel recycling process. This method utilizes high-temperature calcination to decompose the encapsulation layer between the silicon wafer and glass, completely separating the glass from the silicon wafer, facilitating screening. Separating the mixed fragments allows for further recycling of both materials, increasing material recovery rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic diagram of a photovoltaic debris screening system in use according to an embodiment of the present application.

[0025] FIG2 is a schematic structural diagram of a screen in a photovoltaic debris screening system according to an embodiment of the present application.

[0026] Figure numerals: 1. glass; 2. silicon wafer; 3. material receiving tray; 4. screen. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present application, but should not be understood as limiting the present application.

[0028] According to the photovoltaic fragment screening system of the embodiment of the present application, as shown in Figures 1 and 2, the photovoltaic fragment screening system includes a screen 4, a vibrating member, a material receiving tray 3 and a control mechanism. The screen 4 is used to screen photovoltaic fragments, the vibrating member is used to drive the screen 4 to vibrate, and the material receiving tray 3 is used to receive the screened photovoltaic fragments. The control mechanism includes a weighing device and a vibration control device. The vibration control device is connected to the vibrating member to control the vibration of the vibrating member. The weighing device is electrically connected to the vibration control device to send the weight information of the silicon wafer 2 material on the screen 4 to the vibration control device. The vibration control device controls the vibration of the vibrating member according to the weight information of the silicon wafer 2 material. The screening system controls the vibration speed and direction of the vibrating element through a control mechanism. The vibrating element drives the screen 4 to vibrate so that the glass 1 in the photovoltaic fragments on the screen 4 stays above the screen 4, while the silicon wafer 2 passes through the gap of the screen 4 and falls onto the material receiving tray 3. The control mechanism detects the weight information of the silicon wafer 2 material on the material receiving tray 3 through a weighing device to determine the screening effect of the screen 4. The vibration speed and vibration direction of the vibrating element are adjusted according to the screening effect, so that the screening system can have the best screening efficiency and screening effect.

[0029] The photovoltaic debris screening system according to the embodiment of the present application has the advantages and technical effects of high screening efficiency, thorough material separation, and high material recovery rate.

[0030] In some embodiments, the vibration control device includes a data processor, a weighing device records the weight of the material receiving tray 3 within a preset time period, the data processor obtains the falling speed of the silicon wafer material based on the time and weight data, and the vibration control device controls the vibration of the vibrating part according to the falling speed of the silicon wafer material.

[0031] Specifically, the data processor can be a computer or other data processing device. The weighing device weighs the material receiving tray 3. The data processor collects and processes the weight data. The vibration control device controls the vibration of the vibrating element based on the data processor's output. A time period can be one second or shorter, such as a 0.1 second time interval. The weight of the silicon wafer 2 on the material receiving tray 3 is recorded once during each time period. The drop rate of the silicon wafer 2 material is the ratio of the difference between the weight value of the subsequent time period and the weight value of the previous time period to the time period. After switching the vibration mode, the drop rate of the silicon wafer 2 material is compared to determine the most effective vibration mode, thereby improving screening efficiency.

[0032] In some embodiments, the screen 4 is a unidirectional screen 4 .

[0033] Specifically, the conventional screen 4 is formed by the intersection of longitude and latitude lines. The single-directional screen 4 facilitates the falling of the silicon wafers 2 and ensures screening efficiency. Therefore, the vibration direction of the screen 4 can range from parallel to the weaving direction of the screen 4 itself to perpendicular to the weaving direction of the screen 4 itself. The vibration direction can also be dynamically rotated clockwise or counterclockwise, thereby playing the role of screening the silicon wafers 2.

[0034] In some embodiments, the spacing of the screen 4 is adjusted according to the equivalent diameter and thickness of the photovoltaic fragments to complete the separation of the glass 1 and the silicon wafer 2.

[0035] Specifically, the spacing between the screens 4 should be smaller than the equivalent diameter of the glass 1 in the photovoltaic debris and larger than the thickness of the silicon wafer 2 to facilitate separation of the glass 1 and silicon wafer 2. Increasing the spacing increases screening efficiency but reduces screening quality. Reducing the spacing reduces screening efficiency but improves screening quality to prevent glass 1 from falling. The spacing between the screens 4 can be optimized to strike a balance between screening efficiency and screening quality. A spacing between 0.2 mm and 1 mm provides optimal screening results.

[0036] According to the method for separating the glass plate and silicon wafer of a photovoltaic module according to an embodiment of the present application, the method for separating the glass plate and silicon wafer of a photovoltaic module comprises the following steps:

[0037] The photovoltaic panel is fired within a preset temperature range of 450°C to 700°C, with the outer frame removed. The high temperature completely decomposes the encapsulation layer between the silicon wafer 2 and the glass 1, separating the tempered glass 1 and the silicon wafer 2 without any remaining encapsulation layer.

[0038] Collect the material fragments after baking; after high temperature baking, the photovoltaic panel will break due to stress, the glass 1 will break into pieces, and the silicon wafer 2 including the crystalline silicon and the accompanying electrode layer, anti-reflection layer, etc. will break into irregular thin slices.

[0039] The screening system is turned on to screen the material fragments. The screening system determines the vibration mode with the highest screening efficiency according to the falling speed of the silicon wafer 2;

[0040] The vibrating element maintains the vibration mode with the highest screening efficiency until the screening is completed. The screening system vibrates and screens the silicon wafer 2 and the glass 1 in the vibration mode with the highest screening efficiency, ensuring the separation of the glass 1 and the silicon wafer 2.

[0041] In some embodiments, after large-sized fragments and long welding strips are sorted out from the fired material fragments, the glass 1 in the fired material fragments is broken into fragments with an equivalent diameter of 3 to 8 mm, and the silicon wafer 2 is broken into irregular thin slices with a thickness of 0 to 0.2 mm.

[0042] Specifically, the glass 1 and silicon wafer 2 are uniformly processed and crushed into small fragments of the target size, facilitating subsequent screening and improving screening efficiency. The state of the glass and silicon wafer after crushing is affected by factors such as the firing temperature and glass type. The firing temperature and time can be adjusted based on the desired fragment size and the type of raw material. Pre-sorting large fragments and solder strips from the fragments reduces processing steps and shortens crushing time.

[0043] Optionally, multiple screens of different sizes can be added to pre-screen the calcined fragments multiple times to obtain fragments within the target particle size range. The oversized fragments that do not pass the screening process can be re-crushed, either mechanically or manually.

[0044] In some embodiments, the weight value of the silicon wafer 2 in the target time period is subtracted from the weight of the silicon wafer 2 in the adjacent time period to obtain the weight difference, and the falling speed of the silicon wafer 2 is the ratio of the weight difference to the time period.

[0045] Specifically, a curve can be obtained by integrating the acquired weight data with time, and the slope of the curve is the falling speed of the silicon wafer. The number of time periods selected for calculating the falling speed of the silicon wafer 2 can be the total length of any time periods.

[0046] In some embodiments, the screen 4 maintains the same vibration mode during several time periods, and all vibration modes are traversed to obtain the vibration mode with the maximum falling speed of the silicon wafer 2, thereby obtaining the screening mode with the highest screening efficiency.

[0047] Specifically, the number of time periods selected for calculating the falling speed of the silicon wafer 2 can be any total length of the time periods, such as 1 time period or 10 time periods. Several time periods are grouped together, and the vibration mode within a group is kept consistent, which facilitates the testing of the screening effect. Different groups are vibrated using different vibration modes.

[0048] In some embodiments, the glass 1 on the screen 4 is discharged to the glass receiving tray after reaching the target weight.

[0049] Specifically, after the glass 1 remaining on the screen 4 reaches the target weight, it is cleaned to prevent the accumulated material from being too heavy and damaging the screen 4. The glass 1 on the screen 4 is discharged to the glass receiving tray, which receives the glass 1 fragments. The target weight should be less than the upper limit of the load of the screen 4.

[0050] The technical advantages of the method for separating the photovoltaic module glass plates and silicon wafers according to the embodiment of the present application are the same as the technical advantages of the above-mentioned photovoltaic debris screening system, and will not be repeated here.

[0051] Example 1

[0052] For the recycling of the waste photovoltaic modules of Project A, the first step is to dismantle the frames and junction boxes of the waste photovoltaic modules, and then bake the disassembled photovoltaic panels.

[0053] After the photovoltaic modules are calcined at 550°C, they enter the screening process.

[0054] The screen 4 is made of stainless steel wire mesh with a wire mesh spacing of 0.7 mm.

[0055] The system automatically tests the falling speed of the silicon wafer 2 in two vibration directions: parallel to the screen 4 and perpendicular to the screen 4. Each vibration direction vibrates continuously for 30 seconds. The weighing device uses an electronic balance with an accuracy of 0.01g, and records the weight of the silicon wafer 2 on the material receiving tray 3 every 1 second.

[0056] The results show that the falling speed of the silicon wafer 2 is greater when the vibration mode is perpendicular to the direction of the screen 4.

[0057] After completing the data recording, the system selects a vibration mode perpendicular to the direction of the screen 4 and screens continuously for 6 minutes to fully separate the silicon wafer 2 and the glass 1.

[0058] Example 2

[0059] For the recycling of the waste photovoltaic modules of Project B, the first step is to dismantle the frames and junction boxes of the waste photovoltaic modules, and then bake the disassembled photovoltaic panels.

[0060] After the photovoltaic modules are calcined at 650°C, they enter the screening process.

[0061] The screen 4 is made of stainless steel wire mesh with a mesh spacing of 0.4 mm.

[0062] The system automatically tests the falling speed of the silicon wafer 2 in two vibration directions, parallel to the screen 4 and perpendicular to the screen 4. Each vibration direction vibrates continuously for 10 seconds. The weighing device uses an electronic balance with an accuracy of 0.01g, and records the weight of the silicon wafer 2 on the material receiving tray 3 every 0.5 seconds.

[0063] The results show that the silicon wafer 2 falls faster when vibrating at an angle of 45° to the screen 4.

[0064] After completing the data recording, the system selects a vibration mode at a 45° angle to the screen 4 and continuously screens for 10 minutes to fully separate the silicon wafer 2 and the glass 1.

[0065] Comparative Example

[0066] For the recycling of the waste photovoltaic modules of Project B, the first step is to dismantle the frames and junction boxes of the waste photovoltaic modules, and then bake the disassembled photovoltaic panels.

[0067] After the photovoltaic modules are calcined at 650°C, they enter the screening process.

[0068] The screen 4 is made of stainless steel wire mesh with a mesh spacing of 0.4 mm.

[0069] Turn off the system and do not automatically select the vibration mode, but maintain the vibration mode perpendicular to the screen 4 and continue to vibrate.

[0070] After 30 minutes of continuous screening, the silicon wafer 2 and the glass 1 were still not completely separated.

[0071] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0073] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0074] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0075] In this application, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0076] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations on the present application. Changes, modifications, substitutions and variations of the above embodiments made by ordinary technicians in this field are all within the scope of protection of the present application.

Claims

1. A photovoltaic debris screening system, characterized in that: include A screen, the screen being used to screen photovoltaic debris; a vibrating member, the vibrating member being used to drive the screen to vibrate; A material receiving tray, the material receiving tray is used to receive the photovoltaic fragments after screening; A control mechanism includes a weighing device and a vibration control device, the vibration control device is connected to the vibrating member to control the vibration of the vibrating member, the weighing device is electrically connected to the vibration control device to send the weight information of the silicon flake material on the screen to the vibration control device, and the vibration control device controls the vibration of the vibrating member according to the weight information of the silicon flake material.

2. The photovoltaic debris screening system according to claim 1, characterized in that: The vibration control device includes a data processor, the weighing device records the weight of the material receiving tray within a preset time period, the data processor obtains the falling speed of the silicon wafer based on the time and weight data, and the vibration control device controls the vibration of the vibrating member according to the falling speed of the silicon wafer.

3. The photovoltaic debris screening system according to claim 1, characterized in that: The screen is a single-direction screen.

4. The photovoltaic debris screening system according to claim 3, characterized in that: The spacing of the screens is adjusted according to the equivalent diameter and thickness of the photovoltaic fragments to complete the separation of glass and silicon wafers.

5. The photovoltaic debris screening system according to claim 4, characterized in that: The spacing between the screens is 0.2 mm to 1 mm.

6. A method for separating a photovoltaic module glass plate and a silicon wafer, characterized in that: The following steps are involved: Firing photovoltaic panels within a preset temperature range; Collecting the roasted material fragments; Start the screening system to screen the material fragments, the screening system is claim 1 The photovoltaic debris screening system according to any one of claim 5 to 5, wherein the screening system determines a vibration mode with the highest screening efficiency based on the falling speed of the silicon wafers; The vibrating element maintains a vibration mode with maximum screening efficiency until screening is completed.

7. The method for separating photovoltaic module glass plates and silicon wafers according to claim 6, characterized in that: After large-sized fragments and long welding strips are sorted out from the baked material fragments, the glass in the baked material fragments is broken into fragments with an equivalent diameter of 3 to 8 mm, and the silicon wafers are broken into irregular thin slices with a thickness of 0 to 0.2 mm.

8. The method for separating photovoltaic module glass plates and silicon wafers according to claim 6, characterized in that: The weight value of the silicon wafer in the target time period is subtracted from the weight of the silicon wafer in the adjacent time period to obtain the weight difference. The falling speed of the silicon wafer is the ratio of the weight difference to the time period.

9. The method for separating photovoltaic module glass plates and silicon wafers according to claim 6, characterized in that: The screen maintains the same vibration mode during several time periods, and all vibration modes are traversed to obtain the vibration mode with the maximum falling speed of the silicon wafer, thereby obtaining the screening mode with the highest screening efficiency.

10. The method for separating photovoltaic module glass plates and silicon wafers according to claim 6, characterized in that: The glass on the screen is discharged to the glass receiving tray after reaching the target weight.

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