Silver-coated copper powder drying pretreatment unit for photovoltaic cell

Abstract

The utility model discloses a photovoltaic cell silver-coated copper powder drying pretreatment unit which comprises a drying box, a vacuum pump used for vacuumizing and drying the interior of the drying box and a plurality of bearing racks used for placing silver-coated copper powder are arranged on the drying box, and the bearing racks are arranged in the drying box through bolts. A plurality of containing grooves used for containing silver-coated copper powder drying plates are formed in each bearing rack, the silver-coated copper powder drying plates slide in the containing grooves, and segmented drying mechanisms used for conducting segmented uniform drying on the silver-coated copper powder are arranged at the positions, close to the containing grooves, of the drying box and aim at conducting segmented protective drying on the silver-coated copper powder. Silver-coated copper powder is uniformly heated and dried through automatic scraping operation, caking is avoided, intelligent positioning and all-directional protection and dust filtration are carried out in the drying process, a large amount of dust is prevented from being caused during scraping operation, and dust pollution in the drying box is reduced.

Description

Technical Field

[0001] The utility model relates to the field of photovoltaic cells, in particular to a silver-coated copper powder drying pretreatment unit for photovoltaic cells. Background Art

[0002] Solar cells are typical two-terminal devices, consisting of silicon wafers, passivation films, and metal electrodes. As the core material of the photovoltaic industry chain, the quality of silicon wafers directly affects the photoelectric conversion efficiency, and photovoltaic silver paste is the key material for preparing metal electrodes for solar cells. Solar cell manufacturers use screen printing to print photovoltaic silver paste on both sides of silicon wafers, and then dry and sinter them to form the two-terminal electrodes of solar cells. Photovoltaic silver paste is a basic material with silver powder as the main raw material. It is a viscous paste of a mechanical mixture composed of high-purity silver powder, glass oxide, organic materials, etc.

[0003] At present, the silver-coated copper technology is used to optimize the cost reduction of the silver paste material itself. After the silver paste material is optimized, it is superimposed with metallic copper to further reduce the cost of the silver paste. The resistance and density of the silver-coated copper powder are between those of silver powder and copper powder, and the resistance decreases with the increase of pressure, while the specific surface area of ​​the silver-coated copper powder is higher than that of the silver powder and copper powder. The particle size of the silver-coated copper powder ranges from 2 microns to 4 microns, and the particle size shapes of the silver-coated copper are spherical and flaky. The morphology of the copper particles has an important influence on the coating. The more nano-sized and atomically arranged the coated particles are, the denser the coating layer is, which can provide higher temperature resistance.

[0004] The essence of cost reduction of silver-coated copper is to replace part of the silver in the silver paste with base metal copper, cover the copper with silver, and continuously adjust the doping ratio of silver and copper through experiments to improve the photoelectric conversion efficiency, while ensuring a certain efficiency and reducing the cost of silver paste. Silver-coated copper powder is prepared on the basis of ultrafine copper powder products. The quality of ultrafine copper powder will directly affect the performance of the final silver-coated copper;

[0005] At present, silver-coated copper powder is dried centrally after filtering, but the bottom and top of the silver-coated copper powder are easily agglomerated during drying due to uneven heating, and the overall drying efficiency is low. In addition, due to the lack of protection during the drying process, a large amount of dust is easily generated during the drying process and cannot be filtered, resulting in pollution in the drying box and loss of silver-coated copper powder. The present application aims to set up segmented protective drying for the silver-coated copper powder, and to dry the silver-coated copper powder evenly through automated scraping operation to avoid agglomeration. Through intelligent positioning and all-round protective dust filtration during the drying process, a large amount of dust can be avoided during the scraping operation, thereby reducing dust pollution inside the drying box. Utility Model Content

[0006] The utility model aims to provide a drying pretreatment unit for silver-coated copper powder for photovoltaic cells to solve the problems in the prior art.

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] A drying pretreatment unit for silver-coated copper powder for photovoltaic cells comprises a drying box, on which a vacuum pump for vacuum drying the interior of the drying box and a plurality of supporting frames for placing the silver-coated copper powder are provided, the supporting frames are arranged inside the drying box by bolts, a plurality of placement slots for placing silver-coated copper powder drying plates are arranged inside each of the supporting frames, the silver-coated copper powder drying plates slide inside the placement slots, a segmented drying mechanism for segmented and uniform drying of the silver-coated copper powder is provided near the plurality of placement slots in the drying box, the segmented drying mechanism comprises a drying protective cover for sequentially drying and protecting the silver-coated copper powder inside the drying plates.

[0009] By adopting the above technical scheme: the vacuum pump can draw vacuum inside the drying box to achieve vacuum drying of the silver-coated copper powder, the carrying frame can place and fix the silver-coated copper powder, the placement groove is used to set up and dry each silver-coated copper powder drying plate, and the segmented drying mechanism can evenly dry the silver-coated copper powder inside different silver-coated copper powder drying plates one by one to prevent the silver-coated copper powder from agglomerating, and the drying protective cover can protect and filter the dust when the silver-coated copper powder is dried in sequence.

[0010] Further arrangement: the segmented drying mechanism includes a positioning guide rail for driving the drying protection box to perform sliding fixed-point drying. The positioning guide rail is arranged on the side walls of the drying box on both sides close to the drying protection box, and the drying protection box is slidably connected to the positioning guide rail. The drying box is provided with a push cylinder for driving the drying protection box to move at a fixed point inside the positioning guide rail. The drying protection box includes an operating top plate for uniformly drying the silver-coated copper powder and a dust filter cover for filtering dust during drying. The dust filter cover and the operating top plate are detachably connected.

[0011] By adopting the above technical solution: the positioning guide rail can locate the position of the drying protection box and move it to the designated position to dry the silver-coated copper powder, the push cylinder inside the positioning guide rail can drive the drying protection box to move to the designated place, and the silver-coated copper powder can be scraped by operating the top plate to make the silver-coated copper powder evenly dried to avoid agglomeration caused by uneven heating, and the dust filter cover can filter the dust raised by the silver-coated copper powder during the scraping operation to avoid a large amount of dust being raised and causing pollution.

[0012] Further arrangement: a plurality of positioning grooves for positioning the drying position of the drying protective cover are provided near each placement slot on the supporting frame, a telescopic card block for positioning and fixing the drying protective cover in the positioning slot is provided on the dust filter cover, the telescopic card block is slidably connected inside the dust filter cover, a position sensor for sensing the position of the telescopic card block is provided inside the positioning groove, the position sensor is electrically connected to the telescopic card block, a sensing groove for sensing the fixed position of the drying protective cover is provided between the positioning groove and the adjacent positioning groove, a plurality of telescopic sensing blocks for lifting and sensing the position of the silver-coated copper powder in the placement slot are provided near the telescopic card block of the dust filter cover, the telescopic sensing block is electrically connected to the position sensor, a first contact sensor for sensing the descent of the telescopic sensing block is provided inside the sensing groove.

[0013] By adopting the above technical solution: the positioning groove can position the drying position of the drying protective cover, and the telescopic card blocks at the four corners of the dust filter cover are extended and retracted, so that the telescopic card blocks are clamped in the positioning groove for position limiting, and the sensing groove can sense the position of the drying protective cover, and the telescopic sensing block inside the dust filter cover is lifted and lowered and clamped in the sensing groove, and the first contact sensor can sense the telescopic sensing block, thereby sensing and positioning the drying protective cover.

[0014] Further configuration: a movable groove is provided inside the operating top plate, a scraper is provided inside the movable groove for evenly drying the silver-coated copper powder to prevent agglomeration, the scraper is movably connected inside the movable groove, an auxiliary heating plate for auxiliary drying is provided near the scraper in the movable groove, the auxiliary heating plates are respectively provided on both sides of the scraper, the auxiliary heating plates are detachably connected to the scraper and movably connected inside the movable groove at the same time, a movable cylinder is provided inside the movable groove for driving the scraper and the auxiliary heating plate to move simultaneously, and the movable cylinder is electrically connected to the first contact sensor.

[0015] By adopting the above technical solution: the scraper can scrape the silver-coated copper powder on the silver-coated copper powder drying plate, so as to avoid the silver-coated copper powder from agglomerating due to uneven heating; the auxiliary heating plate can evenly heat the silver-coated copper powder while scraping it, thereby improving the heating rate of the silver-coated copper powder; the first contact sensor senses that the drying protective cover moves to above the silver-coated copper powder drying plate in the placement slot, thereby driving the scraper and the auxiliary heating plate to move simultaneously through the moving cylinder, so that the silver-coated copper powder can be scraped and heated and dried at the same time.

[0016] Further configuration: Electric heating dryers for centralized drying of the silver-coated copper powder inside the drying box are respectively arranged on the top and bottom of the drying box.

[0017] By adopting the above technical solution: the electric heating dryers at the top and bottom can increase the heating temperature inside the drying box, preheat the silver-coated copper powder that has not been scraped, and avoid the silver-coated copper powder being heated too slowly, which affects the heating efficiency of the silver-coated copper powder.

[0018] It is further configured that a second contact sensor for sensing the silver-coated copper powder drying plate is provided inside each placement slot, and the second contact sensor is electrically connected to the push cylinder.

[0019] By adopting the above technical solution: the second contact sensor can sense the silver-coated copper powder drying plate inside the placement slot, thereby turning on the push cylinder to sequentially dry the silver-coated copper powder on the position of the silver-coated copper powder drying plate placed on the placement slot.

[0020] Compared with the prior art, the beneficial effects of the utility model are: it aims to set up segmented protective drying for silver-coated copper powder, and through automated scraping operation, the silver-coated copper powder is evenly heated for drying to avoid agglomeration, and through intelligent positioning and all-round protective dust filtration during the drying process, a large amount of dust is avoided during the scraping operation, thereby reducing dust pollution inside the drying box. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0022] Figure 1 It is a partial cross-sectional schematic diagram of a drying pretreatment unit of silver-coated copper powder for photovoltaic cells according to the utility model;

[0023] Figure 2 This is a schematic diagram of the overall cross-section of a photovoltaic cell silver-coated copper powder drying pretreatment unit of the utility model. Figure 1 ;

[0024] Figure 3 This is a schematic diagram of the overall cross-section of a photovoltaic cell silver-coated copper powder drying pretreatment unit of the utility model. Figure 2 ;

[0025] Figure 4 This is a partial diagram of a drying pretreatment unit for silver-coated copper powder for photovoltaic cells according to the utility model.

[0026] In the figure, 1. drying box; 2. vacuum pump; 3. carrying frame; 4. heating dryer; 5. placement slot; 6. operating top plate; 7. dust filter cover; 8. scraper; 9. auxiliary heating plate; 10. moving cylinder; 11. positioning guide rail; 12. pushing cylinder; 13. second contact sensor; 14. positioning slot; 15. telescopic card block; 16. induction slot; 17. first contact sensor. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] See also Figures 1 to 4 In an embodiment of the utility model, a pretreatment unit for drying silver-coated copper powder for photovoltaic cells includes a drying box 1. The drying box 1 is provided with a vacuum pump 2 for vacuuming and drying the interior of the drying box 1 and a plurality of supporting frames 3 for placing the silver-coated copper powder. The supporting frames 3 are arranged inside the drying box 1 by bolts. The top and bottom of the drying box 1 are respectively provided with electric heating dryers 4 for centrally drying the silver-coated copper powder inside the drying box 1. The electric heating dryers 4 at the top and bottom can increase the heating temperature inside the drying box 1, preheat the silver-coated copper powder that has not been scraped, and avoid the silver-coated copper powder being heated too slowly, which affects the heating efficiency of the silver-coated copper powder.

[0029] Each supporting frame 3 is provided with a plurality of placement slots 5 for placing the silver-coated copper powder drying plates. The silver-coated copper powder drying plates slide inside the placement slots 5. The vacuum pump 2 can extract the vacuum inside the drying box 1 to achieve vacuum drying of the silver-coated copper powder. The supporting frame 3 can place and fix the silver-coated copper powder. The placement slots 5 are used to set up and dry each silver-coated copper powder drying plate.

[0030] The drying box 1 is provided with a segmented drying mechanism for segmented and uniform drying of the silver-coated copper powder near the plurality of placement slots 5. The segmented drying mechanism can evenly dry the silver-coated copper powder inside different silver-coated copper powder drying plates one by one to prevent the silver-coated copper powder from agglomerating.

[0031] The segmented drying mechanism includes a drying protective cover for drying and protecting the silver-coated copper powder inside the drying plate in sequence, the drying protective cover can protect and filter the dust when the silver-coated copper powder is dried in sequence, the drying protective box includes an operating top plate 6 for uniformly operating and drying the silver-coated copper powder and a dust filter cover 7 for filtering dust during drying, the dust filter cover 7 and the operating top plate 6 are detachably connected, the silver-coated copper powder can be scraped through the operating top plate 6, so that the silver-coated copper powder is evenly dried to avoid agglomeration caused by uneven heating, and the dust filter cover 7 can filter the dust raised by the silver-coated copper powder during the scraping operation to avoid a large amount of dust being raised and causing pollution.

[0032] A movable groove is provided inside the operating top plate 6, and a scraper 8 is provided inside the movable groove for uniformly drying the silver-coated copper powder to prevent agglomeration. The scraper 8 is movably connected inside the movable groove, and an auxiliary heating plate 9 for auxiliary drying is provided near the scraper 8 of the movable groove. The auxiliary heating plates 9 are respectively arranged on both sides of the scraper 8, and the auxiliary heating plates 9 are detachably connected to the scraper 8 and movably connected inside the movable groove at the same time. A movable cylinder 10 is provided inside the movable groove for driving the scraper 8 and the auxiliary heating plate 9 to move simultaneously.

[0033] The scraper 8 can scrape the silver-coated copper powder on the silver-coated copper powder drying plate to prevent the silver-coated copper powder from agglomerating due to uneven heating. The auxiliary heating plate 9 can perform uniform heating while scraping the silver-coated copper powder to increase the heating rate of the silver-coated copper powder.

[0034] The segmented drying mechanism also includes a positioning guide rail 11 for driving the drying protection box to slide and dry at a fixed point. The positioning guide rail 11 is arranged on the side walls of the drying box 1 on both sides close to the drying protection box, and the drying protection box is slidably connected to the positioning guide rail 11. The positioning guide rail 11 can locate the position of the drying protection box and move it to a designated position to dry the silver-coated copper powder;

[0035] The drying box 1 is provided with a push cylinder 12 for driving the drying protection box to move at a fixed point inside the positioning guide rail 11. The push cylinder 12 inside the positioning guide rail 11 can drive the drying protection box to move to a designated place. Each placement slot 5 is provided with a second contact sensor 13 for sensing the silver-coated copper powder drying plate. The second contact sensor 13 is electrically connected to the push cylinder 12.

[0036] The second contact sensor 13 can sense the silver-coated copper powder drying plate inside the placement groove 5, thereby turning on the push cylinder 12 to sequentially dry the silver-coated copper powder on the position of the silver-coated copper powder drying plate placed on the placement groove 5.

[0037] The support frame 3 is provided with a plurality of positioning grooves 14 for positioning the drying position of the drying protective cover near each placement groove 5, and the dust filter 7 is provided with a telescopic card setting block 15 for positioning and fixing the drying protective cover in the positioning groove 14. The telescopic card setting block 15 is slidably connected to the dust filter 7, and a position sensor for sensing the position of the telescopic card setting block 15 is provided inside the positioning groove 14. The position sensor is electrically connected to the telescopic card setting block 15, and a sensing groove 16 for sensing the fixed position of the drying protective cover is provided between the positioning groove 14 and the adjacent positioning groove 14. The dust filter 7 is close to the telescopic card setting block 15. A number of telescopic sensing blocks for lifting and lowering the sensing position of the silver-coated copper powder in the placement slot 5 are provided at the position of the retractable sensing block 15. The telescopic sensing blocks are electrically connected to the position sensor. A first contact sensor 17 for sensing the descent of the telescopic sensing block is provided inside the sensing slot 16. The first contact sensor 17 is electrically connected to the moving cylinder 10. The first contact sensor 17 senses that the drying protective cover moves to above the silver-coated copper powder drying plate in the placement slot 5, thereby driving the scraper 8 and the auxiliary heating plate 9 to move simultaneously through the moving cylinder 10, so that the silver-coated copper powder can be scraped and heated and dried at the same time.

[0038] The position sensor inside the positioning groove 14 can locate the drying position of the drying protective cover, sense the position of the telescopic card block 15, and extend and retract the telescopic card blocks 15 at the four corners of the dust filter cover 7, so that the telescopic card blocks 15 are clamped in the positioning groove 14 for position limiting. The sensing groove 16 can sense the position of the drying protective cover, and the telescopic sensing block inside the dust filter cover 7 is lifted and lowered and clamped in the sensing groove 16. The first contact sensor can sense the telescopic sensing block, thereby sensing and positioning the drying protective cover.

[0039] The working principle of the utility model is as follows: the operator places the silver-coated copper powder to be dried on the drying plate, and sequentially places the silver-coated copper powder drying plate inside the placement slot 5 inside the carrying frame 3, and the second contact sensor 13 senses the silver-coated copper powder drying plate inside the placement slot 5, thereby turning on the push cylinder 12 to drive the drying protection box to move at a fixed point inside the positioning guide rail 11, thereby driving the drying protection box to move to a designated position to dry the silver-coated copper powder, and sequentially drying the silver-coated copper powder at the position where the silver-coated copper powder drying plate is placed on the placement slot 5;

[0040] The position sensor inside the positioning groove 14 locates the drying position of the drying protective cover in real time, senses the position of the telescopic clamping block 15, and telescopes the telescopic clamping block 15 at the four corners of the dust filter cover 7, so that the telescopic clamping block 15 is clamped inside the positioning groove 14 for position limiting. The clamping signal of the telescopic clamping block 15 is sent to the telescopic sensing block through the position sensor, driving the telescopic sensing block inside the dust filter cover 7 to descend, and the telescopic sensing block is clamped inside the sensing groove 16. The first contact sensor senses the telescopic sensing block, so as to sense and locate the drying protective cover;

[0041] The first contact sensor 17 senses that the drying protective cover moves to above the silver-coated copper powder drying plate in the placement slot 5, thereby driving the scraper 8 and the auxiliary heating plate 9 to move simultaneously through the moving cylinder 10. The scraper 8 can scrape the silver-coated copper powder on the silver-coated copper powder drying plate, thereby preventing the silver-coated copper powder from agglomerating due to uneven heating. The auxiliary heating plate 9 can perform uniform heating while scraping the silver-coated copper powder, thereby increasing the heating rate of the silver-coated copper powder.

[0042] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

Claims

1. A drying pretreatment unit for silver-coated copper powder for photovoltaic cells, comprising a drying box (1), characterized in that: The drying box (1) is provided with a vacuum pump (2) for vacuum drying the interior of the drying box (1) and a plurality of supporting frames (3) for placing silver-coated copper powder. The supporting frames (3) are arranged inside the drying box (1) by bolts. A plurality of placement slots (5) for placing silver-coated copper powder drying plates are arranged inside each of the supporting frames (3). The silver-coated copper powder drying plates slide inside the placement slots (5). The drying box (1) is provided with a segmented drying mechanism for uniformly drying the silver-coated copper powder in segments at a position close to the plurality of placement slots (5). The segmented drying mechanism includes a drying protective cover for sequentially drying and protecting the silver-coated copper powder inside the drying plates.

2. A photovoltaic cell silver-coated copper powder drying pretreatment unit according to claim 1, characterized in that The segmented drying mechanism comprises a positioning rail (11) for driving a drying protection box to slide and dry at a fixed point. The positioning rail (11) is arranged at a position close to the drying protection box on both side walls of the drying box (1), and the drying protection box is slidably connected to the positioning rail (11). The drying box (1) is provided with a push cylinder (12) for driving the drying protection box to move at a fixed point inside the positioning rail (11). The drying protection box comprises an operating top plate (6) for uniformly drying the silver-coated copper powder and a dust filter cover (7) for filtering dust generated during drying. The dust filter cover (7) and the operating top plate (6) are detachably connected.

3. A photovoltaic cell silver-coated copper powder drying pretreatment unit according to claim 1, characterized in that The bearing frame (3) is provided with a plurality of positioning grooves (14) near each placement groove (5) for positioning the drying position of the drying protective cover; the dust filter cover (7) is provided with a telescopic clamping block (15) for clamping the drying protective cover inside the positioning groove (14) for positioning and fixing; the telescopic clamping block (15) is slidably connected inside the dust filter cover (7); a position sensor for sensing the position of the telescopic clamping block (15) is provided inside the positioning groove (14); the position sensor is electrically connected to the telescopic clamping block (15); a sensing groove (16) for sensing the fixed position of the drying protective cover is provided between the positioning groove (14) and the adjacent positioning groove (14); a plurality of telescopic sensing blocks for lifting and lowering sensing the position of the silver-coated copper powder in the placement groove (5) are provided near the telescopic clamping block (15) of the dust filter cover (7); the telescopic sensing block is electrically connected to the position sensor; a first contact sensor (17) for sensing the descent of the telescopic sensing block and clamped inside the sensing groove (16) is provided inside the sensing groove (16).

4. A photovoltaic cell silver-coated copper powder drying pretreatment unit according to claim 2, characterized in that The operating top plate (6) is provided with a movable groove inside, and a scraper (8) is provided inside the movable groove for uniformly drying the silver-coated copper powder to prevent agglomeration. The scraper (8) is movably connected inside the movable groove. An auxiliary heating plate (9) for auxiliary drying is provided near the scraper (8) in the movable groove. The auxiliary heating plates (9) are respectively arranged on both sides of the scraper (8). The auxiliary heating plates (9) are detachably connected to the scraper (8) and are movably connected inside the movable groove at the same time. A movable cylinder (10) is provided inside the movable groove for driving the scraper (8) and the auxiliary heating plate (9) to move simultaneously. The movable cylinder (10) is electrically connected to the first contact sensor (17).

5. A photovoltaic cell silver-coated copper powder drying pretreatment unit according to claim 1, characterized in that The top and bottom of the drying box (1) are respectively provided with electric heating dryers (4) for centrally drying the silver-coated copper powder inside the drying box (1).

6. A photovoltaic cell silver-coated copper powder drying pretreatment unit according to claim 1, characterized in that Each placement slot (5) is provided with a second contact sensor (13) for sensing the silver-coated copper powder drying plate, and the second contact sensor (13) is electrically connected to the push cylinder (12).

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