Separation device and separation method for silicon wafer and crushed glass after pyrolysis of photovoltaic module

Abstract

The invention provides a separation device and a separation method for silicon wafers and broken glass after pyrolysis of photovoltaic modules, the separation device comprises a screening chamber, a screening conveyor belt and a vibration device, a discharge port of the screening chamber is connected with a screening plate, and the vibration device is connected to the bottom of the screening conveyor belt. A mixed material of silicon wafers and broken glass enters a screening chamber, a vibrating device is started, a screening conveying belt is subjected to transverse reciprocating vibration of the vibrating device, the material is evenly laid, a screen plate is driven to open an opening with the height being 2 mm, crystalline silicon passes through the screen plate, meanwhile, the broken glass is stopped from passing through the screen plate, and after crystalline silicon is discharged, the screen plate is driven to be opened to the maximum height. And enabling the crushed glass to pass through the sieve plate. The thickness difference between the silicon wafer and the crushed glass is utilized, the silicon wafer and the crushed glass respectively pass through the sieve plates, and the silicon wafer and the crushed glass are efficiently separated and then recycled.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic pyrolysis, and in particular to a device and method for separating silicon wafers and glass scraps after pyrolysis of a photovoltaic module. Background Art

[0002] Photovoltaic modules are generally composed of aluminum frames, junction boxes, tempered glass, EVA film crystalline silicon cells and TPT backboards. Whole photovoltaic panels refer to the tempered glass panels (whole pieces), EVA film crystalline silicon cells and TPT backboards after the aluminum frames and junction boxes are separated from the photovoltaic modules.

[0003] The chain plate type pyrolysis device is the basis of photovoltaic pyrolysis. The existing chain plate type pyrolysis device includes a chain plate and a feed inlet and outlet. The chain plate is located below the feed inlet. The existing pyrolysis device uses fuel (such as natural gas) or thermocouples to generate high-temperature heat sources to provide the energy required for pyrolysis for the entire pyrolysis device. The pyrolysis temperature is usually ≥500℃, and an inert gas (such as high nitrogen) is required as a carrier gas during the pyrolysis process.

[0004] The purpose of pyrolysis is to pyrolyze and volatilize the bonding glass of photovoltaic modules, the EVA of silicon wafers, and the backplane behind the module. If the photovoltaic modules are broken and then pyrolyzed, the decomposition of organic matter can be greatly accelerated and the separation efficiency of photovoltaic modules can be improved. However, the glass and silicon wafers of the broken photovoltaic modules are mixed together and need to be further separated, which is difficult. The main components of crystalline silicon and glass are silicon, with similar physical properties and similar densities. It is difficult to separate and recover them by electromagnetic sorting, centrifugation, and solution flotation. If separated manually, the efficiency is too low. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the embodiment of the present invention provides a separation device and a separation method for silicon wafers and glass scraps after pyrolysis of photovoltaic modules, which can achieve efficient separation of crystalline silicon and glass.

[0006] The inventors have found through research that there is a thickness difference between silicon wafers and glass, the thickness of silicon wafers is less than 1 mm, and the thickness of glass cullets is greater than 5 mm. Therefore, the thickness difference between silicon wafers and glass cullets can be used to design a separation device for silicon wafers and glass cullets.

[0007] According to an embodiment of the present invention, a device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules is provided, comprising: a screening chamber, a screening conveyor belt and a vibration device, wherein the screening chamber has a feed port and a discharge port, the discharge port of the screening chamber is connected to a screen plate, the screen plate can be opened and closed and connected to the discharge port, the screen plate is connected to a controller, and the controller controls the opening and closing of the screen plate to cause the silicon wafers and glass fragments to be discharged separately; the screening conveyor belt runs through the feed port and the discharge port of the screening chamber, the upstream of the screening conveyor belt is connected to the feed conveyor belt, and the downstream of the screening conveyor belt is connected to the discharge conveyor belt, and the tail end of the screening conveyor belt is tilted downward to cause the material to be discharged from the discharge port of the screening chamber and fall on the discharge conveyor belt; the vibration device is connected to the bottom of the screening conveyor belt, and the vibration device drives the screening conveyor belt to vibrate back and forth in the lateral direction to evenly spread the material on the belt surface of the screening conveyor belt.

[0008] In some embodiments, a row of auxiliary rollers are respectively provided on the inner walls on both sides of the screening chamber. The auxiliary rollers are located above the screening conveyor belt, and the auxiliary rollers drive the silicon wafers and glass fragments to be transmitted along the transmission direction of the screening conveyor belt.

[0009] In some embodiments, a first wind pressure device is provided on the top of the screening chamber, and the first wind pressure device is provided near the discharge port of the screening chamber, and the air outlet of the first wind pressure device points to the belt surface of the screening conveyor belt.

[0010] In some embodiments, the top of the sieve plate is connected to a hydraulic device, which drives the sieve plate to rise and fall, and the hydraulic device is connected to a controller.

[0011] In some embodiments, a collecting device is provided below the tail end of the discharge conveyor belt, and the collecting device includes a switchable silicon wafer recovery tray and a glass crushing material recovery tray, and the silicon wafer recovery tray and the glass crushing material recovery tray are connected to a switching mechanism, and the switching mechanism is connected to a controller.

[0012] In some embodiments, a monitoring device is provided above the screening chamber, and the monitoring device is connected to a controller.

[0013] In some embodiments, a plurality of second wind pressure devices are provided on the side walls of the screening chamber, and the second wind pressure devices are respectively provided between two adjacent auxiliary rollers. The air outlets of the second wind pressure devices point to the auxiliary rollers on the opposite side to blow away the materials stuck between the two adjacent auxiliary rollers, and the second wind pressure devices are connected to the controller.

[0014] In some embodiments, each of the auxiliary rollers is connected to a reducer.

[0015] In some embodiments, the auxiliary roller is in sliding contact with the belt surface of the screening conveyor belt.

[0016] Another embodiment of the present invention provides a method for separating silicon wafers and glass scraps after pyrolysis of photovoltaic modules, using the above-mentioned separation device, comprising the following steps:

[0017] After the broken photovoltaic modules are decarbonized by pyrolysis, a mixture of silicon wafers and glass fragments is obtained. The mixture is transported to the screening conveyor belt through the feed conveyor belt and enters the screening chamber; the vibration device is started, and the screening conveyor belt is vibrated horizontally and reciprocatingly by the vibration device, and the mixed material is evenly spread on the belt surface of the screening conveyor belt, and the material is accelerated by the rotation of the auxiliary roller to accelerate the transmission of the mixed material; the mixed material is blocked by the sieve plate at the discharge port of the screening chamber, and the sieve plate is driven to open an opening of 2mm in height to allow the crystalline silicon to pass through, while blocking the passage of the glass fragments. After passing through the sieve plate, the crystalline silicon falls on the discharge conveyor belt and then falls into the silicon wafer recovery tray for recovery; after the monitoring device detects that the crystalline silicon is discharged, the sieve plate is driven to open to the maximum height to allow the glass fragments to pass through the sieve plate, and the silicon wafer recovery tray is switched to the glass fragment recovery tray to recover the glass fragments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings.

[0019] in:

[0020] Figure 1 It is a schematic structural diagram of a device for separating silicon wafers and glass scraps after pyrolysis of a photovoltaic module in an embodiment of the present invention;

[0021] Figure 2 for Figure 1 A top view of

[0022] Reference numerals:

[0023] 1. Silicon wafers and glass fragments; 2. Feed conveyor belt; 3. Monitoring device; 4. Controller; 5. Screening chamber; 6. First wind pressure device; 7. Screen plate; 8. Switching mechanism; 9. Silicon wafer recovery tray; 10. Auxiliary roller; 11. Screening conveyor belt; 12. Vibration device; 13. Discharge conveyor belt; 14-Glass fragment recovery tray. DETAILED DESCRIPTION

[0024] Embodiments of the present invention 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 invention, but should not be understood as limiting the present invention.

[0025] The following describes the device and method for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to an embodiment of the present invention with reference to the accompanying drawings.

[0026] like Figure 1 ,2 As shown, an embodiment of the present invention provides a separation device for silicon wafers and glass cullets after pyrolysis of photovoltaic modules, comprising: a screening chamber 5, a screening conveyor belt 11 and a vibrating device 12, the screening chamber 5 having a feed port and a discharge port, the discharge port of the screening chamber 5 connected to a sieve plate 7, the sieve plate 7 can be opened and closed and connected to the discharge port, the sieve plate 7 is connected to a controller 4, the controller 4 controls the opening and closing of the sieve plate 7 to facilitate the discharge of silicon wafers and glass cullets 1 respectively; the screening conveyor belt 11 runs through the feed port of the screening chamber 5 The outlet and the discharge outlet of the screening conveyor belt 11 are connected, the upstream of the screening conveyor belt 11 is connected to the feed conveyor belt 2, and the downstream of the screening conveyor belt 11 is connected to the discharge conveyor belt 13. The tail end of the screening conveyor belt 11 is tilted downward to promote the material to be discharged from the discharge outlet of the screening chamber 5 and fall on the discharge conveyor belt 13; the vibration device 12 is connected to the bottom of the screening conveyor belt 11, and the vibration device 12 drives the screening conveyor belt 11 to vibrate reciprocatingly in the horizontal direction to evenly spread the material on the belt surface of the screening conveyor belt 11.

[0027] In the embodiment of the present invention, a sieve plate 7 with a controllable lifting height is arranged at the discharge port of the screening chamber 5, and the thickness difference between the silicon wafer and the glass cullet 1 is utilized to pass the silicon wafer and the glass cullet 1 through the sieve plate 7 respectively, so as to achieve efficient separation and recycling. The screening conveyor belt 11 is arranged to be tilted downward, which helps to transport the silicon wafer and the glass cullet 1 toward the discharge port of the screening chamber 5. The vibrating device 12 is arranged below the screening conveyor belt 11 to drive the screening conveyor belt 11 to vibrate back and forth in the lateral direction (relative to the material transmission direction), so as to evenly spread the material on the belt surface of the screening conveyor belt 11.

[0028] Furthermore, the tail end of the discharge conveyor belt 13 is tilted downward, which is helpful for material transmission.

[0029] In some embodiments, a row of auxiliary rollers 10 are respectively provided on the inner walls of both sides of the screening chamber 5, and the auxiliary rollers 10 are located above the screening conveyor belt 11. The auxiliary rollers 10 drive the silicon wafers and glass fragments to be transported along the transmission direction of the screening conveyor belt 11. The auxiliary rollers 10 can assist in the rapid transmission of silicon wafers and glass fragments 1.

[0030] Furthermore, two adjacent auxiliary rollers 10 in each row fit together.

[0031] In some embodiments, a first wind pressure device 6 is provided at the top of the screening chamber 5, and the first wind pressure device 6 is provided at a position close to the discharge port of the screening chamber 5, and the air outlet of the first wind pressure device 6 points to the belt surface of the screening conveyor belt 11. By providing the first wind pressure device 6 at a position close to the top of the sieve plate 7, wind pressure can be applied to the moving direction of the broken materials, so as to promote the stable transmission of the materials and prevent the glass broken materials from warping, thereby blocking the sieve plate 7.

[0032] Furthermore, the first wind pressure device 6 is disposed on the top of the screening chamber 5 .

[0033] Furthermore, the first wind pressure device 6 is connected to the controller 4, and the controller 4 drives the first wind pressure device 6 to apply wind pressure.

[0034] In some embodiments, the top of the sieve plate 7 is connected to a hydraulic device, which drives the sieve plate 7 to rise and fall, and the hydraulic device is connected to the controller 4 .

[0035] In some embodiments, a collecting device is provided below the tail end of the discharge conveyor belt 13 , and the collecting device includes a switchable silicon wafer recovery tray 9 and a glass fragment recovery tray 14 , and the silicon wafer recovery tray 9 and the glass fragment recovery tray 14 are connected to a switching mechanism 8 , and the switching mechanism 8 is connected to a controller 4 .

[0036] Furthermore, the switching mechanism 8 can be implemented by a hydraulic cylinder. Specifically, the cylinder rod of the hydraulic cylinder connects the silicon wafer recovery tray 9 and the glass cullet recovery tray 14. The silicon wafer recovery tray 9 and the glass cullet recovery tray 14 are fixedly connected by a connecting rod. The silicon wafer recovery tray 9 is fixedly connected between the glass cullet recovery tray 14 and the cylinder rod of the hydraulic cylinder. When silicon wafer recovery is required, the hydraulic cylinder is driven to move the silicon wafer recovery tray 9 to the bottom of the tail end of the discharge conveyor belt 13; when glass cullet recovery is required, the hydraulic cylinder is driven to move the glass cullet recovery tray 14 to the bottom of the tail end of the discharge conveyor belt 13.

[0037] In some embodiments, a monitoring device 3 is provided above the screening chamber 5 , and the monitoring device 3 is connected to the controller 4 .

[0038] The screening situation in the screening chamber 5 is observed by the monitoring device 3. When it is monitored that the crystalline silicon has completely passed through and the recovery is completed, and only glass fragments are left in the screening chamber 5, the monitoring device 3 feeds back the information to the controller 4. The controller 4 drives the hydraulic device of the sieve plate 7 to drive the sieve plate 7 to move upward to a fully open state. Then the controller 4 drives the switching mechanism 8 to switch the silicon wafer recovery tray 9 to the glass fragment recovery tray 14.

[0039] Furthermore, the monitoring device 3 can judge the remaining material in the screening chamber 5 by color. Silicon wafers are black, and glass is transparent and whitish. When there are no black fragments in the judging area, the screen plate 7 is fully opened. It should be noted that the belt of the screening conveyor belt 11 is recommended to be light-colored to avoid interference and misjudgment.

[0040] In some alternative embodiments, the monitoring device 3 can be replaced by a manual observation method. The sieve plate 7, the switching mechanism 8 and other devices are opened or closed by manual operation.

[0041] In some embodiments, a plurality of second wind pressure devices are provided on the side wall of the screening chamber 5, and the second wind pressure devices are respectively provided between two adjacent auxiliary rollers 10, and the air outlet of the second wind pressure device points to the auxiliary roller 10 on the opposite side to blow away the material stuck between the two adjacent auxiliary rollers 10, and the second wind pressure device is connected to the controller 4. When the monitoring device 3 detects that there is material stuck between the auxiliary rollers 10, the second wind pressure device at the corresponding position is activated to blow the material away.

[0042] In some embodiments, each auxiliary roller 10 is connected to a reducer. The rotation speed of the auxiliary roller 10 can be adjusted according to the transmission conditions of the materials in the screening chamber 5.

[0043] In some embodiments, the auxiliary roller 10 is in sliding contact with the belt surface of the screening conveyor belt 11 .

[0044] Another embodiment of the present invention provides a method for separating silicon wafers and glass scraps after pyrolysis of photovoltaic modules, using the above-mentioned separation device, comprising the following steps:

[0045] After the broken photovoltaic modules are decarbonized by pyrolysis, a mixture of silicon wafers and glass fragments is obtained, which is transported to the screening conveyor belt 11 through the feed conveyor belt 2 and enters the screening chamber 5; the vibration device 12 is started, and the screening conveyor belt 11 is evenly spread on the belt surface of the screening conveyor belt 11 under the lateral reciprocating vibration of the vibration device 12, and the material is accelerated by the rotation of the auxiliary roller 10 to accelerate the transmission of the mixed material; the mixed material is blocked by the sieve plate 7 at the discharge port of the screening chamber 5, and the sieve plate 7 is driven to open an opening of 2mm in height to allow the crystalline silicon to pass through, while blocking the passage of the glass fragments. After passing through the sieve plate 7, the crystalline silicon falls on the discharge conveyor belt 13, and then falls into the silicon wafer recovery tray 9 for recovery; after the monitoring device 3 monitors that the crystalline silicon is discharged, the sieve plate 7 is driven to open to the maximum height to allow the glass fragments to pass through the sieve plate 7, and the silicon wafer recovery tray 9 is switched to the glass fragment recovery tray 14 to recover the glass fragments.

[0046] The embodiment of the present invention utilizes the thickness difference between silicon wafers and glass cullets 1 to pass silicon wafers and glass cullets 1 through the sieve plate 7 respectively, so as to achieve efficient separation and recycling. A vibration device 12 is arranged below the screening conveyor belt 11 to drive the screening conveyor belt 11 to vibrate back and forth in the lateral direction, so as to evenly spread the materials on the belt surface of the screening conveyor belt 11.

[0047] In the description of the present invention, it is to 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”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0049] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature 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. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. 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 invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0052] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A device for separating silicon wafers and glass scraps after pyrolysis of photovoltaic modules, characterized in that: include: A screening chamber, wherein the screening chamber has a feed port and a discharge port, the discharge port of the screening chamber is connected to a screening plate, the screening plate can be opened and closed and connected to the discharge port, the screening plate is connected to a controller, and the controller controls the opening and closing of the screening plate to facilitate the discharge of silicon wafers and glass fragments respectively; A screening conveyor belt, the screening conveyor belt runs through the feed port and the discharge port of the screening chamber, the upstream of the screening conveyor belt is connected with the feed conveyor belt, the downstream of the screening conveyor belt is connected with the discharge conveyor belt, and the tail end of the screening conveyor belt is tilted downward to promote the material to be discharged from the discharge port of the screening chamber and fall on the discharge conveyor belt; A vibration device is connected to the bottom of the screening conveyor belt, and the vibration device drives the screening conveyor belt to vibrate back and forth in the lateral direction to evenly spread the material on the belt surface of the screening conveyor belt.

2. The device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to claim 1, characterized in that: A row of auxiliary rollers are respectively arranged on the inner walls on both sides of the screening chamber. The auxiliary rollers are located above the screening conveyor belt. The auxiliary rollers drive the silicon wafers and glass fragments to be transmitted along the transmission direction of the screening conveyor belt.

3. The device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to claim 1, characterized in that: A first wind pressure device is provided on the top of the screening chamber. The first wind pressure device is provided at a position close to the discharge port of the screening chamber. The air outlet of the first wind pressure device points to the belt surface of the screening conveyor belt.

4. The device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to claim 1, characterized in that: The top of the sieve plate is connected to a hydraulic device, which drives the sieve plate to rise and fall, and the hydraulic device is connected to the controller.

5. The device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to claim 1, characterized in that: A collecting device is provided below the tail end of the discharging conveyor belt, and the collecting device includes a switchable silicon wafer recovery tray and a glass cullet recovery tray. The silicon wafer recovery tray and the glass cullet recovery tray are connected to a switching mechanism, and the switching mechanism is connected to the controller.

6. The device for separating silicon wafers and glass scraps after pyrolysis of photovoltaic modules according to claim 1, characterized in that: A monitoring device is provided above the screening chamber, and the monitoring device is connected to the controller.

7. The device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to claim 2, characterized in that: A plurality of second wind pressure devices are provided on the side walls of the screening chamber, and the second wind pressure devices are respectively arranged between two adjacent auxiliary rollers. The air outlets of the second wind pressure devices point to the auxiliary rollers on the opposite side to blow away the materials stuck between the two adjacent auxiliary rollers. The second wind pressure devices are connected to the controller.

8. The device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to claim 2, characterized in that: Each of the auxiliary rollers is connected to a reducer.

9. The device for separating silicon wafers and glass fragments after pyrolysis of photovoltaic modules according to claim 2, characterized in that: The auxiliary roller is in sliding contact with the belt surface of the screening conveyor belt.

10. A method for separating silicon wafers and glass scraps after pyrolysis of photovoltaic modules, characterized in that: Using the separation device according to any one of claims 1 to 9, comprising the following steps: After the broken photovoltaic modules are decarbonized by pyrolysis, a mixture of silicon wafers and glass scraps is obtained. The mixture is transported to the screening conveyor belt through the feeding conveyor belt and enters the screening chamber. The vibration device is started, and the screening conveyor belt is subjected to the lateral reciprocating vibration of the vibration device, and the mixed material is evenly spread on the belt surface of the screening conveyor belt, and the material is accelerated to be transmitted under the rotation of the auxiliary roller; The mixed material is blocked by the sieve plate at the discharge port of the screening chamber, and the sieve plate is driven to open an opening with a height of 2 mm to allow the crystalline silicon to pass through, while blocking the passage of the glass fragments. After passing through the sieve plate, the crystalline silicon falls on the discharge conveyor belt and then falls into the silicon wafer recovery tray for recovery; After the monitoring device detects that the discharging of the crystalline silicon is completed, the sieve plate is driven to open to the maximum height to allow the glass fragments to pass through the sieve plate, and the silicon wafer recovery tray is switched to a glass fragment recovery tray to recover the glass fragments.

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