A gradient sieving purification device for monolayer graphene dispersion

Abstract

This application relates to the field of graphene sieving technology and discloses a gradient sieving and purification device for a single-layer graphene dispersion. It mainly consists of a support frame, a purification cylinder, a spiral feed blade, a primary sieving device, and a secondary sieving device. A scraper I is fixedly connected to the outer surface of sieving cylinder I, with the end of scraper I away from sieving cylinder I contacting the inner wall of sieving cylinder II. A magnetic strip is fixedly connected to the outer surface of sieving cylinder II, with scraper II fixedly connected to the end of the magnetic strip away from sieving cylinder II. In this invention, when sieving and purifying the graphene dispersion in sieving cylinder I, the centrifugal force of sieving cylinder I is used for sieving. Large graphene particles remain inside sieving cylinder I, while some graphene adheres to the inner wall of sieving cylinder II under centrifugal force. Then, the rotation of sieving cylinder I rotates scraper I, scraping off the graphene adhering to the inner wall of sieving cylinder II, preventing the mesh of sieving cylinder II from being blocked by graphene.

Description

Technical Field

[0001] This application relates to the field of graphene sieving technology, and in particular to a gradient sieving and purification device for monolayer graphene dispersion. Background Technology

[0002] Graphene is an allotrope of carbon, and monolayer graphene is a single-layer hexagonal honeycomb lattice structure formed by carbon atoms bonded by sp² hybridization, with a thickness of only 0.335 nanometers. Using this crystal structure of graphene, fullerenes, graphene quantum dots, carbon nanotubes, nanoribbons, multi-walled carbon nanotubes, and nanoangles can be constructed. Stacked graphene layers (more than 10 layers) form graphite, which is held together by van der Waals forces. Graphene has excellent optical, electrical, and mechanical properties and has important application prospects in materials science, micro-nano fabrication, energy, biomedicine, and drug delivery. It is considered an important material for the future.

[0003] Graphene dispersions are produced by uniformly dispersing graphene sheets in a solvent (such as water or organic solvents) using physical or chemical methods to form a stable suspension. Their core advantage lies in preserving the intrinsic properties of graphene. However, due to the strong adhesion properties of graphene itself, large graphene particles can easily remain inside the graphene dispersion during the production process, leading to a decrease in the purity of the dispersion. Therefore, graphene dispersions need to be purified by sieving.

[0004] Existing graphene dispersion sieving and purification equipment mainly uses centrifugal sieves. These sieves work by using centrifugal force to retain large graphene particles inside the sieving cylinder, while qualified graphene dispersions pass through and are collected. During this process, due to centrifugal force, some large graphene particles adhere to the inner wall of the sieve cylinder. The strong adhesion properties of graphene can clog the mesh, affecting sieving efficiency. Furthermore, while single sieving can effectively separate large graphene particles, after the dispersion passes through the sieve cylinder, some larger graphene particles adsorb surrounding graphene powder, leading to the reappearance of large graphene particles in the dispersion. Therefore, secondary sieving is necessary for graphene dispersion sieving. Moreover, the liquid nature of graphene dispersions results in a short residence time inside the sieve cylinder, leading to incomplete sieving and ultimately poor purification. Summary of the Invention

[0005] This application proposes a gradient sieving and purification device for monolayer graphene dispersion, which has the advantages of improving the sieving effect and efficiency of graphene dispersion and ensuring thorough sieving of graphene dispersion. It is used to solve technical problems such as incomplete sieving and graphene easily adhering to the sieving cylinder and causing blockage during the sieving and purification of graphene dispersion.

[0006] To achieve the above objectives, this application adopts the following technical solution: a gradient sieving purification device for monolayer graphene dispersion, comprising a support frame, and further comprising:

[0007] A support base is fixedly connected to the top of the support frame. A purification cylinder is fixedly installed on the upper surface of the support base. A cylinder cover is hinged to the left side wall of the purification cylinder. A motor I is fixedly installed on the right side wall of the purification cylinder through a mounting plate. A drive shaft is fixedly connected to the output end of the motor I.

[0008] A feed cylinder is fixedly connected to the middle of the right side wall of the purification cylinder. A feed pipe is fixedly connected to the upper side of the feed cylinder. A spiral feed blade is movably arranged inside the feed cylinder. The end of the drive shaft away from motor I extends into the feed cylinder and is fixedly connected to the spiral feed blade. A primary sieving device is arranged inside the purification cylinder. A secondary sieving device is arranged inside the purification cylinder.

[0009] Furthermore, the primary screening device includes:

[0010] Screening cylinder I is rotatably disposed inside the purification cylinder, and the feed cylinder is connected to screening cylinder I;

[0011] A fixing rod is fixedly sleeved at the end of the drive shaft away from the spiral feed blade, and both ends of the fixing rod are fixedly connected to the inner wall of the screening cylinder I;

[0012] Rubber baffle I is located on the left side of the screening cylinder I;

[0013] The first discharge cylinder is fixedly sleeved in the middle of the rubber partition I, and the first discharge cylinder is connected to the left opening of the screening cylinder I.

[0014] Furthermore, the secondary screening device includes:

[0015] Screening cylinder II is located outside the screening cylinder I;

[0016] A fixing ring is fixedly connected to the left side of the inner wall of the purification cylinder.

[0017] The sealing plate is bolted to the left side wall of the fixing ring;

[0018] Motor II is fixedly installed in the middle of the sealing plate. The output shaft of motor II is fixedly connected to the left side wall of screening cylinder II. The right end of screening cylinder II is rotatably connected to a second discharge cylinder.

[0019] Furthermore, the first discharge cylinder includes:

[0020] Through hole I is located on the lower part of the side wall of the first discharge cylinder;

[0021] Through hole II is formed on the lower part of the side wall of the screening cylinder II and corresponds to through hole I;

[0022] Discharge pipe I is fixedly connected to the bottom of the purification cylinder and corresponds to the through hole II;

[0023] Rubber partition II is fixedly sleeved on the outer surface of the screening cylinder II and located on the right side of the through hole II.

[0024] Furthermore, the second discharge cylinder includes:

[0025] Discharge pipe II is fixedly connected to the bottom of the second discharge cylinder, and the lower part of discharge pipe II penetrates the bottom wall of the purification cylinder and is fixedly connected to the purification cylinder.

[0026] The discharge pipe III is fixedly connected to the middle of the bottom surface of the purification cylinder.

[0027] Furthermore, the screening cylinder I includes:

[0028] Scraper I is fixedly connected to the outer surface of the screening cylinder I, and the end of scraper I away from screening cylinder I is in contact with the inner wall of screening cylinder II.

[0029] Furthermore, the screening cylinder II includes:

[0030] Magnetic strips are fixedly connected to the outer surface of the screening cylinder II;

[0031] Scraper II is fixedly connected to the end of the magnetic strip away from the sieving cylinder II, and the end of scraper II away from the magnetic strip is in contact with the inner wall of the purification cylinder.

[0032] Furthermore, the first discharge cylinder includes:

[0033] The rotating shaft is rotatably connected to the middle of the inner wall of the first discharge cylinder;

[0034] A magnetic spiral blade is fixedly connected to the end of the rotating shaft away from the first discharge cylinder, and the direction of rotation of the magnetic spiral blade is opposite to that of the spiral feed blade.

[0035] The baffle is fixedly connected to the magnetic spiral blade;

[0036] Spiral grooves are formed on the outer surface of the magnetic spiral blade;

[0037] A coil spring is disposed on the outer surface of the rotating shaft. One end of the coil spring is fixedly connected to the outer surface of the rotating shaft, and the other end of the coil spring is fixedly connected to the inner wall of the first discharge cylinder.

[0038] Furthermore, the outer surface of the magnetic spiral blade slides in contact with the inner wall of the screening cylinder I, the magnetic spiral blade is within the magnetic field range of the magnetic strip, the magnetism of the magnetic spiral blade is opposite to that of the magnetic strip, and the rotation directions of the screening cylinder I and the screening cylinder II are opposite.

[0039] This application provides a gradient sieving and purification device for a single-layer graphene dispersion. By designing a sieve cylinder II, scraper I, and scraper II, when the graphene dispersion enters the sieve cylinder I for sieving and purification, centrifugal force is used for sieving. Large graphene particles remain inside the sieve cylinder I, while some graphene adheres to the inner wall of the sieve cylinder II due to centrifugal force. Then, the rotation of the sieve cylinder I causes the scraper I to rotate, scraping off the graphene adhering to the inner wall of the sieve cylinder II, preventing the mesh of the sieve cylinder II from being blocked by graphene. Simultaneously, due to… The scraper is made of rubber, and the inclination directions of screening cylinder I and screening cylinder II are opposite. This causes scraper I to twist during rotation, and the twist caused by scraper I will recover at the large gap between screening cylinder I and screening cylinder II. As scraper I releases elastic potential energy during recovery, the graphene attached to scraper I will return to the centrifugal force range of screening cylinder I and continue to be centrifuged and screened. Similarly, scraper II on screening cylinder II will also scrape off the graphene attached to the inner wall of the purification cylinder and promote the graphene to return to the centrifugal range of screening cylinder II to continue to be screened.

[0040] By designing magnetic spiral blades, baffles, spiral grooves, and magnetic strips, when screening cylinder II rotates, the rubber partition I is pressed against the inner wall of screening cylinder II by pressure. At this time, screening cylinder II uses the magnetic attraction of the rubber partition I and magnetic strips on the magnetic spiral blades to drive the first discharge cylinder and the magnetic spiral blades to rotate. Since the rotation direction of the magnetic spiral blades is opposite to that of the spiral feed blades, the graphene dispersion entering the screening cylinder I is squeezed between the spiral feed blades and the magnetic spiral blades, causing the graphene to quickly separate from the liquid after being squeezed, thereby improving screening efficiency.

[0041] Meanwhile, due to the design of the baffles and magnetic strips, when the graphene inside screening cylinder I is propelled towards the inner wall of screening cylinder I by centrifugal force, the scattered graphene will collide with the baffles, causing the agglomerated graphene to disperse upon impact, thereby improving the screening effect. Furthermore, the design of the magnetic spiral blades and magnetic strips allows the graphene dispersion to be subjected to the force of a magnetic field, which can significantly improve the transport efficiency of spin-polarized charge carriers in graphene, enabling the agglomerated graphene to disperse rapidly and further improving the screening effect of the graphene dispersion.

[0042] Secondly, by designing magnetic spiral blades, spiral grooves, and coil springs, when the screening cylinder II rotates with the first discharge cylinder via the rubber partition I, and the magnetic strip uses magnetic attraction to rotate the magnetic spiral blades, the coil spring will be wound up by the force of the rotating shaft, allowing the coil spring to store energy. When the potential energy of the coil spring is greater than the sum of the frictional force between the rubber partition I and the screening cylinder II and the magnetic attraction force of the magnetic strip on the magnetic spiral blades, the potential energy of the coil spring is released, causing the rotating shaft to rotate in the opposite direction with the magnetic spiral blades. At this time, large-particle graphene will be pushed into the first discharge cylinder by the reverse-rotating magnetic spiral blades, while graphene of the appropriate size will be blocked by the spiral grooves and continue to remain inside the screening cylinder I for screening. Furthermore, when the magnetic spiral blades are rotated by the magnetic strips, the residence time of the graphene dispersion inside the screening cylinder I will be extended, which can maximize the screening of the graphene dispersion and promote more thorough screening of the graphene dispersion, thereby improving the purification effect of graphene. Attached Figure Description

[0043] The accompanying drawings, which form part of this specification, illustrate embodiments disclosed in this application and, together with the specification, serve to explain the principles disclosed in this application.

[0044] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0045] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0046] Figure 2 This is a schematic diagram of the internal structure of the purification tube of the present invention;

[0047] Figure 3 This is a schematic diagram of the internal structure of the screening cylinder I of the present invention;

[0048] Figure 4 This is a schematic diagram of the internal structure of the screening cylinder II of the present invention;

[0049] Figure 5 This is a schematic diagram of the assemblies of screening cylinder I and screening cylinder II of the present invention.

[0050] Figure 6 This is a schematic diagram of the structure of the magnetic spiral blade of the present invention.

[0051] The components are as follows: 1. Support frame; 2. Support base; 3. Purification cylinder; 4. Cylinder cover; 5. Motor I; 6. Drive shaft; 7. Feed cylinder; 8. Feed pipe; 9. Spiral feed blade; 10. Fixed rod; 11. Screening cylinder I; 110. Scraper I; 12. Fixed ring; 13. Sealing plate; 14. Motor II; 15. Screening cylinder II; 151. Magnetic strip; 152. Scraper II; 16. Rubber partition I; 17. First discharge cylinder; 171. Rotating shaft; 172. Magnetic spiral blade; 173. Baffle; 174. Spiral groove; 175. Coil spring; 18. Through hole I; 19. Through hole II; 20. Discharge pipe I; 21. Rubber partition II; 22. Second discharge cylinder; 23. Discharge pipe II; 24. Discharge pipe III. Detailed Implementation

[0052] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0053] Please see Figures 1-6 A gradient sieving purification device for a single-layer graphene dispersion includes a support frame 1, a support base 2 fixedly installed at the top of the support frame 1, a purification cylinder 3 fixedly installed on the upper surface of the support base 2, a cylinder cover 4 hinged to the left side wall of the purification cylinder 3, a motor I 5 fixedly installed on the right side wall of the purification cylinder 3 via a mounting plate, a drive shaft 6 fixedly connected to the output end of the motor I 5, a feed cylinder 7 fixedly installed in the middle of the right side wall of the purification cylinder 3, a feed pipe 8 fixedly connected to the upper side of the feed cylinder 7, a spiral feed blade 9 movably arranged inside the feed cylinder 7, one end of the drive shaft 6 away from the motor I 5 extending into the feed cylinder 7 and fixedly connected to the spiral feed blade 9, the spiral feed blade 9 driving the raw material into the interior of the purification cylinder 3, a primary sieving device and a secondary sieving device are arranged inside the purification cylinder 3.

[0054] Please see Figures 1-6The primary screening device includes a screening cylinder I11, which is rotatably installed inside the purification cylinder 3. The feed cylinder 7 is connected to the screening cylinder I11, ensuring that the raw material inside the feed cylinder 7 is pushed into the screening cylinder I11 by the spiral feed blade 9. A fixed rod 10 is fixedly sleeved at the end of the drive shaft 6 away from the spiral feed blade 9. The two ends of the fixed rod 10 are fixedly connected to the inner wall of the screening cylinder I11, ensuring that the motor I5 drives the spiral feed blade 9 to rotate while the fixed rod 10 drives the screening cylinder I11 to rotate synchronously. The centrifugal force generated by the rotation of the screening cylinder I11 is used to screen the graphene dispersion. A rubber partition I16 is provided on the left side of the screening cylinder I11. A first discharge cylinder 17 is fixedly sleeved in the middle of the rubber partition I16. The first discharge cylinder 17 is connected to the left opening of the screening cylinder I11, ensuring that the large graphene particles screened out inside the screening cylinder I11 will enter the first discharge cylinder 17.

[0055] Please see Figures 1-6 The secondary screening device includes a screening cylinder II 15, which is located on the outside of screening cylinder I 11 to ensure that the dispersion after screening in screening cylinder I 11 enters screening cylinder II 15 for secondary screening. A fixing ring 12 is fixedly connected to the left side wall of the inner cavity of purification cylinder 3. A sealing plate 13 is installed on the left side wall of the fixing ring 12 by bolts. A motor II 14 is fixedly installed in the middle of the sealing plate 13. The output shaft of motor II 14 is fixedly connected to the left side wall of screening cylinder II 15 to ensure that motor II 14 can drive screening cylinder II 15 to rotate, thereby using the centrifugal force of screening cylinder II 15 to screen the dispersion. A second discharge cylinder 22 is rotatably connected to the right end of screening cylinder II 15 to ensure that the graphene particles screened out by screening cylinder II 15 enter the second discharge cylinder 22.

[0056] Please see Figures 1-6 The lower side wall of the first discharge cylinder 17 has a through hole I18 to ensure that large graphene particles in the first discharge cylinder 17 will be discharged through the through hole I18. The lower side wall of the screening cylinder II15 has a through hole II19 corresponding to the through hole I18. The large graphene particles discharged through the through hole I18 will be blocked by the rubber partition I16, so that the large graphene particles can only be discharged through the through hole II19. The bottom of the purification cylinder 3 is fixedly connected to the discharge pipe I20 corresponding to the through hole II19. The outer surface of the screening cylinder II15 is fixedly fitted with a rubber partition II21 on the right side of the through hole II19. The large graphene particles discharged through the through hole II19 will be blocked by the rubber partition II21, so that the large graphene particles can only be discharged and collected through the discharge pipe I20.

[0057] Please see Figures 1-6The bottom of the second discharge cylinder 22 is fixedly connected to the discharge pipe II 23, ensuring that the graphene particles screened out at the sieve cylinder II 15 will be discharged through the discharge pipe II 23 and collected. The lower part of the discharge pipe II 23 penetrates the bottom wall of the purification cylinder 3 and is fixedly connected to the purification cylinder 3. The middle of the bottom surface of the purification cylinder 3 is fixedly connected to the discharge pipe III 24. The qualified graphene dispersion after two screenings will pass through the sieve cylinder II 15 and finally be discharged through the discharge pipe III 24 and collected.

[0058] Please see Figures 1-6 A scraper I110 is fixedly connected to the outer surface of the screening cylinder I11. The end of the scraper I110 away from the screening cylinder I11 contacts the inner wall of the screening cylinder II15, so that the scraper I110 can scrape off the graphene attached to the inner wall of the screening cylinder II15 and prevent the mesh on the screening cylinder II15 from being blocked.

[0059] Please see Figures 1-6 A magnetic strip 151 is fixedly connected to the outer surface of the sieve cylinder II 15. A scraper II 152 is fixedly connected to the end of the magnetic strip 151 away from the sieve cylinder II 15. The end of the scraper II 152 away from the magnetic strip 151 contacts the inner wall of the purification cylinder 3, so that the scraper II 152 can scrape off the graphene attached to the inner wall of the purification cylinder 3.

[0060] Please see Figures 1-6 A rotating shaft 171 is rotatably connected to the middle of the inner wall of the first discharge cylinder 17. A magnetic spiral blade 172 is fixedly connected to the end of the rotating shaft 171 away from the first discharge cylinder 17. A baffle 173 is fixedly connected to the magnetic spiral blade 172. Through the design of the baffle 173, the graphene particles in the dispersion liquid will collide with the baffle 173. The graphene particles after the collision are easily dispersed, thereby reducing the generation of large graphene particles. A spiral groove 174 is opened on the outer surface of the magnetic spiral blade 172. Since large graphene particles cannot enter the spiral groove 174 due to volume limitations, the spiral groove 174 can promote qualified graphene particles to stay inside the screening cylinder I11 for full screening and will not be discharged at the same time as large graphene particles. A coil spring 175 is provided on the outer surface of the rotating shaft 171. One end of the coil spring 175 is fixedly connected to the outer surface of the rotating shaft 171, and the other end of the coil spring 175 is fixedly connected to the inner wall of the first discharge cylinder 17.

[0061] Please see Figures 1-6The outer surface of the magnetic spiral blade 172 slides in contact with the inner wall of the screening cylinder I11. Since the rotation direction of the screening cylinder I11 is opposite to that of the magnetic spiral blade 172, the magnetic spiral blade 172 can scrape off the graphene attached to the inner wall of the screening cylinder I11 during rotation, preventing the mesh of the screening cylinder I11 from clogging. The rotation direction of the magnetic spiral blade 172 is opposite to that of the spiral feed blade 9. The magnetic spiral blade 172 is within the magnetic field range of the magnetic strip 151. The magnetism of the magnetic spiral blade 172 is opposite to that of the magnetic strip 151, which facilitates the magnetic attraction between the magnetic strip 151 and the magnetic spiral blade 172 to drive the magnetic spiral blade 172 to rotate when the screening cylinder II15 rotates. The rotation directions of the screening cylinder I11 and the screening cylinder II15 are opposite.

[0062] Working Principle: When the graphene dispersion needs to be screened and purified, the outlet pipe of the graphene dispersion is connected to the feed pipe 8, and then motor I5 is turned on. Motor I5 drives the spiral feed blade 9 to rotate through the drive shaft 6, allowing the graphene dispersion to enter the screening cylinder I11. Then, motor I5 drives the screening cylinder I11 to rotate through the drive shaft 6 and the fixed rod 10, thereby using the centrifugal force of the rotating screening cylinder I11 to screen and purify the graphene dispersion. At the same time, motor II14 is turned on, and motor II14 drives the screening cylinder II15 to rotate. The raw material screened by screening cylinder I11 will enter the screening cylinder II15 for secondary screening. During this process, due to the centrifugal force, some graphene adheres to the inner wall of the screening cylinder II15, and then the screening cylinder... The rotation of screen I11 causes scraper I110 to rotate as well. Scraper I110 scrapes off the graphene adhering to the inner wall of screen cylinder II15, preventing the mesh on screen cylinder II15 from being blocked by graphene. Simultaneously, because scraper I110 is made of rubber and the inclination directions of screen cylinders I11 and II15 are opposite, scraper I110 will twist during rotation. This twisting will recover at the large gap between screen cylinders I11 and II15. During this recovery process, scraper I110 releases elastic potential energy, causing the graphene adhering to scraper I110 to return to the centrifugal force range of screen cylinder I11 and continue centrifugal sieving. Similarly, scraper II152 on screen cylinder II15 will also... The graphene adhering to the inner wall of the purification cylinder 3 is scraped off, and the graphene is returned to the centrifugal range of the sieving cylinder II 15 for further sieving. When the sieving cylinder II 15 rotates, the rubber partition I 16 is pressed against the inner wall of the sieving cylinder II 15. At this time, the sieving cylinder II 15 uses the magnetic attraction of the rubber partition I 16 and the magnetic strip 151 to the magnetic spiral blade 172, causing the first discharge cylinder 17 and the magnetic spiral blade 172 to rotate. Since the rotation direction of the magnetic spiral blade 172 is opposite to that of the spiral feed blade 9, the graphene dispersion entering the sieving cylinder I 11 is compressed between the spiral feed blade 9 and the magnetic spiral blade 172, causing the graphene to quickly separate from the liquid after being compressed, thereby improving the sieving efficiency. When the sieving cylinder I 11... When the graphene inside is propelled towards the inner wall of the screening cylinder I11 by centrifugal force, the scattered graphene impacts the baffle 173, causing the agglomerated graphene to disperse upon impact, thereby improving the screening effect. Furthermore, the design of the magnetic spiral blade 172 and magnetic strip 151 subjects the graphene dispersion to a magnetic field, which significantly enhances the transport efficiency of spin-polarized charge carriers in the graphene, allowing the agglomerated graphene to disperse rapidly and further improving the screening effect. When the screening cylinder II15 rotates with the first discharge cylinder 17 via the rubber partition I16, and the magnetic strip 151 uses magnetic attraction to rotate the magnetic spiral blade 172, the coil spring 175 is wound up by the force of the rotating shaft 171.This allows the coil spring 175 to store energy. When the potential energy of the coil spring 175 is greater than the sum of the frictional force between the rubber partition I 16 and the screening cylinder II 15 and the magnetic attraction force of the magnetic strip 151 on the magnetic spiral blade 172, the potential energy of the coil spring 175 is released, causing the rotating shaft 171 to rotate in the opposite direction with the magnetic spiral blade 172. At this time, large-particle graphene will be pushed into the first discharge cylinder 17 by the reverse-rotating magnetic spiral blade 172, while graphene that meets the size requirements will be blocked by the spiral groove 174 and continue to remain inside the screening cylinder I 11 for screening. Secondly, when the magnetic spiral blade 172 is rotated by the magnetic strip 151, it will cause the graphene dispersion liquid to... The extended residence time inside screening cylinder I11 allows for more thorough screening of the graphene dispersion, improving purification efficiency. After screening, large graphene particles enter screening cylinder II15 through through-hole I18. Due to the obstruction of rubber baffle I16, these particles can only be discharged into discharge pipe I20 through through-hole II19. Qualified graphene, due to the tilting action of screening cylinder II15, moves to the second discharge cylinder 22 and is finally discharged through discharge pipe II23. The screened liquid passes through screening cylinder II15 and is discharged through discharge pipe III24.

Claims

1. A gradient sieving purification device for a single-layer graphene dispersion, comprising a support frame (1), characterized in that, Also includes: Support base (2) is fixedly connected to the top of the support frame (1). A purification cylinder (3) is fixedly installed on the upper surface of the support base (2). A cylinder cover (4) is hinged to the left side wall of the purification cylinder (3). A motor I (5) is fixedly installed on the right side wall of the purification cylinder (3) through a mounting plate. A drive shaft (6) is fixedly connected to the output end of the motor I (5). The feed cylinder (7) is fixedly connected to the middle of the right side wall of the purification cylinder (3). The feed pipe (8) is fixedly connected to the upper side of the feed cylinder (7). The spiral feed blade (9) is movably arranged inside the feed cylinder (7). The end of the drive shaft (6) away from the motor I (5) extends into the feed cylinder (7) and is fixedly connected to the spiral feed blade (9). The purification cylinder (3) is equipped with a primary screening device and a secondary screening device. The primary screening device includes: Screening cylinder I (11) is rotatably disposed in the inner cavity of the purification cylinder (3), and the feed cylinder (7) is connected to the screening cylinder I (11); A fixing rod (10) is fixedly sleeved on one end of the transmission shaft (6) away from the spiral feed blade (9), and the two ends of the fixing rod (10) are fixedly connected to the inner wall of the screening cylinder I (11); Rubber partition I (16) is disposed on the left side of the screening cylinder I (11); The first discharge cylinder (17) is fixedly sleeved in the middle of the rubber partition I (16), and the first discharge cylinder (17) is connected to the left opening of the screening cylinder I (11); The secondary screening device includes: Screening cylinder II (15) is located outside the screening cylinder I (11); The screening cylinder II (15) includes: Magnetic strip (151) is fixedly connected to the outer surface of the screening cylinder II (15); Scraper II (152) is fixedly connected to one end of the magnetic strip (151) away from the sieve cylinder II (15), and the end of the scraper II (152) away from the magnetic strip (151) is in contact with the inner wall of the purification cylinder (3); The first discharge cylinder (17) includes: The rotating shaft (171) is rotatably connected to the middle of the inner wall of the first discharge cylinder (17); A magnetic spiral blade (172) is fixedly connected to one end of the rotating shaft (171) away from the first discharge cylinder (17), and the direction of rotation of the magnetic spiral blade (172) is opposite to that of the spiral feed blade (9); A baffle (173) is fixedly connected to the magnetic spiral blade (172); Spiral grooves (174) are formed on the outer surface of the magnetic spiral blade (172); A coil spring (175) is disposed on the outer surface of the rotating shaft (171). One end of the coil spring (175) is fixedly connected to the outer surface of the rotating shaft (171), and the other end of the coil spring (175) is fixedly connected to the inner wall of the first discharge cylinder (17). The outer surface of the magnetic spiral blade (172) slides in contact with the inner wall of the screening cylinder I (11). The magnetic spiral blade (172) is within the magnetic field range of the magnetic strip (151). The magnetism of the magnetic spiral blade (172) is opposite to that of the magnetic strip (151). The rotation directions of the screening cylinder I (11) and the screening cylinder II (15) are opposite.

2. The gradient sieving purification device for a single-layer graphene dispersion according to claim 1, characterized in that: A fixing ring (12) is fixedly connected to the left side of the inner wall of the purification cylinder (3); The sealing plate (13) is bolted to the left side wall of the fixing ring (12); Motor II (14) is fixedly installed in the middle of the sealing plate (13). The output shaft of motor II (14) is fixedly connected to the left side wall of screening cylinder II (15). The right end of screening cylinder II (15) is rotatably connected to a second discharge cylinder (22).

3. The gradient sieving purification device for a single-layer graphene dispersion according to claim 2, characterized in that, The first discharge cylinder (17) includes: Through hole I (18) is opened on the lower part of the side wall of the first discharge cylinder (17); Through hole II (19) is opened on the lower part of the side wall of the screening cylinder II (15) and corresponds to through hole I (18); The discharge pipe I (20) is fixedly connected to the bottom of the purification cylinder (3) and corresponds to the through hole II (19); Rubber partition II (21) is fixedly sleeved on the outer surface of the screening cylinder II (15) and located on the right side of the through hole II (19).

4. The gradient sieving purification device for a single-layer graphene dispersion according to claim 3, characterized in that, The second discharge cylinder (22) includes: The discharge pipe II (23) is fixedly connected to the bottom of the second discharge cylinder (22), and the lower part of the discharge pipe II (23) penetrates the bottom wall of the purification cylinder (3) and is fixedly connected to the purification cylinder (3); The discharge pipe III (24) is fixedly connected to the middle of the bottom surface of the purification cylinder (3).

5. The gradient sieving purification device for a single-layer graphene dispersion according to claim 4, characterized in that, The screening cylinder I (11) includes: Scraper I (110) is fixedly connected to the outer surface of the screening cylinder I (11), and the end of scraper I (110) away from screening cylinder I (11) is in contact with the inner wall of screening cylinder II (15).

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