Device for recycling waste plastics to prepare graphene based on carbonization electric shock method

Abstract

The device for preparing graphene from waste plastics based on carbonization electric shock method belongs to the field of plastic recycling. The device is used for solving the problems of low safety factor, high energy consumption and high requirement for raw materials of the Joule heat flash evaporation technology. The device comprises a heating barrel, two receiving hoppers, a magnetic conveying mechanism, an electric shock mechanism and a supporting platform. The heating barrel, the two receiving hoppers, the magnetic conveying mechanism and the electric shock mechanism are fixedly installed on the supporting platform respectively. The discharge port of the heating barrel is connected with the feed port of one of the receiving hoppers. The discharge port of the receiving hopper corresponds to the feed end of the horizontally arranged magnetic conveying mechanism. The discharge end of the magnetic conveying mechanism corresponds to the feed port of the other receiving hopper. The discharge port of the other receiving hopper corresponds to the electric shock platform of the electric shock mechanism. The device is mainly used for recycling plastics and preparing graphene.

Description

Technical Field

[0001] This invention belongs to the field of plastic recycling, and particularly relates to an apparatus for preparing graphene from waste plastics based on a carbonization electrostatic method. Background Technology

[0002] In 2020, Professor James's research group at Rice University first developed and proposed the Joule thermal flash evaporation technology, which uses paint-based plastics as reactants to rapidly heat the plastics to 3000K within tens of milliseconds, and then cools them to room temperature within seconds.

[0003] During the discharge process, the varnished plastic is rapidly heated and graphitized, forming flash graphene. While Joule flash evaporation technology can recycle waste plastics and produce graphene, several problems remain. First, this technology requires high temperatures and oxygen isolation, resulting in a low safety factor. Second, it can only recycle varnished plastics; other types of plastics cannot be recycled. When multiple waste plastics are mixed, the raw materials need to be screened, or the different types of graphene produced later need to be screened, a cumbersome process. Third, although the reaction rate is fast, Joule flash evaporation consumes a lot of energy, and byproducts are not effectively utilized, hindering industrial-scale production. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an apparatus for preparing graphene from recycled waste plastics based on a carbonization electrostatic method. The apparatus converts plastic particles into carbon powder through a heating tank and a catalyst within the tank, and then converts the carbon powder into graphene through electrostatic discharge, thus realizing the conversion of plastic particles into graphene.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] An apparatus for preparing graphene from recycled waste plastics using a carbonization electrostatic method includes a heating tank, two receiving funnels, a magnetic conveying mechanism, an electrostatic mechanism, and a support platform. The heating tank is used to carbonize waste plastic particles; the receiving funnels are used to guide the aggregation and flow of carbon powder; the magnetic conveying mechanism is used to separate carbon powder from the catalyst; and the electrostatic mechanism is used to convert the carbon powder. The heating tank, two receiving funnels, magnetic conveying mechanism, and electrostatic mechanism are respectively fixedly mounted on the support platform. The outlet of the heating tank is connected to the inlet of one of the receiving funnels. The outlet of one of the receiving funnels corresponds to the inlet of the horizontally arranged magnetic conveying mechanism. The outlet of the magnetic conveying mechanism corresponds to the inlet of the other receiving funnel. The outlet of the other receiving funnel corresponds to the electrostatic platform of the electrostatic mechanism.

[0007] Furthermore, the support platform includes a horizontal bearing platform and a vertical support plate. The heating barrel, two receiving funnels, and magnetic conveying mechanism are fixedly installed on the vertical support plate by angle brackets. The electric shock mechanism is fixedly installed on the horizontal bearing platform, and an insulating plate is provided between the two.

[0008] Furthermore, the heating barrel includes a cylindrical cover, a barrel body, and several heating elements. The cylindrical cover is fixedly connected to the opening at the top of the barrel body via a flange. A spiral channel is formed along the center line of the barrel body on its inner wall. The inlet of the spiral channel is located at the upper end of the barrel body, and the outlet of the spiral channel is located at the lower end of the barrel body. The inlet on the cylindrical cover corresponds to the inlet at the upper end of the spiral channel. A catalyst is sputtered onto the inner wall of the spiral channel. Several heating elements are installed axially from top to bottom inside the barrel body to heat the plastic granules.

[0009] Furthermore, the catalyst is an iron-cobalt bimetallic catalyst supported on Al2O3.

[0010] Furthermore, the number of heating elements installed from top to bottom gradually increases to achieve gradient heating of the raw materials.

[0011] Furthermore, the magnetic transmission mechanism includes a conveyor belt with magnets, a drive gear, a tensioning wheel, and a drive motor; the drive gear and tensioning wheel are horizontally rotatably mounted on a vertical support plate, the conveyor belt is fitted onto the drive gear and tensioning wheel, and the output end of the drive motor is connected to the drive gear to realize the rotation of the drive gear.

[0012] Furthermore, the electric shock mechanism includes two sets of clamping components, a conductive film, and two electrodes; the two sets of clamping components are arranged opposite to each other, clamping and tensioning both ends of the conductive film; the two electrodes are respectively arranged on the outside of the two sets of clamping components and are respectively fixedly connected to the ends of the conductive film.

[0013] Furthermore, each clamping assembly includes a C-clamp, two graphite conductive electrode plates, a ceramic bolt, and a ceramic nut. The two graphite conductive electrode plates are arranged opposite each other in the C-clamp and clamp the end of the conductive film. The ceramic bolt is inserted into the C-clamp and is located at the upper end of the two graphite conductive electrode plates. The ceramic nut is screwed onto the ceramic bolt and abuts against the graphite conductive electrode plate to achieve clamping of the conductive film.

[0014] The beneficial effects of this invention compared to the prior art are:

[0015] 1. This application converts plastic particles into carbon powder through a heating barrel and a catalyst inside the heating barrel, and then converts the carbon powder into graphene through electric shock. Although it adds a step of converting plastic particles into carbon powder compared with the Joule heat flash evaporation technology, there are no high requirements for the heating temperature of the plastic particles and the conversion environment in this process. That is, it can be achieved without oxygen isolation conditions, which reduces energy consumption and improves the graphene yield accordingly.

[0016] 2. This application removes the catalyst from the toner powder converted from plastic particles by designing a magnetic transmission mechanism, thereby achieving toner powder filtration, ensuring the purity of the toner powder, and further ensuring the purity of the graphene converted from the toner powder.

[0017] 3. This application does not have requirements on the type of plastic. Compared with the Joule heat flash evaporation technology, which can only achieve the conversion of paint-based plastics, it has a wider range of applications, reduces the screening and filtration of plastic types in the early stage or the screening of graphene in the later stage of conversion, and reduces the number of process steps. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are provided to further illustrate the invention.

[0019] Figure 1 This is an isometric view of the present invention.

[0020] Figure 2 This is the front view of the present invention.

[0021] Figure 3 This is a side view of the present invention.

[0022] Figure 4 This is an isometric view of the heating tank.

[0023] Figure 5 This is a cross-sectional view of the heating tank.

[0024] Explanation of reference numerals in the attached drawings: 1-Heating tank; 1-1-Cylindrical cover; 1-2-Tank body; 1-2-1-Spiral channel; 2-Receiving funnel; 3-Magnetic transmission mechanism; 3-1-Conveyor belt; 3-2-Drive gear; 3-3-Tensioning wheel; 4-Electrical shock mechanism; 4-1-Conductive film; 4-2-Electrode; 4-3-C-clamp; 4-4-Graphite conductive electrode plate; 4-5-Ceramic bolt; 4-6-Ceramic nut; 5-Supporting platform; 5-1-Horizontal bearing platform; 5-2-Vertical support plate; 5-3-Insulating plate. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0026] See Figures 1 to 3 This application provides an apparatus for preparing graphene from recycled waste plastics based on a carbonization electrostatic method. The apparatus includes a heating tank 1, two receiving funnels 2, a magnetic conveying mechanism 3, an electrostatic mechanism 4, and a support platform 5. The heating tank 1 is used to carbonize waste plastic particles; the receiving funnels 2 are used to guide the aggregation and flow of carbon powder; the magnetic conveying mechanism 3 is used to separate carbon powder from the catalyst, achieving carbon powder filtration; and the electrostatic mechanism 4 is used to convert the carbon powder. The heating tank 1, two receiving funnels 2, magnetic conveying mechanism 3, and electrostatic mechanism 4 are respectively fixedly installed on the support platform 5. The outlet of the heating tank 1 is connected to the inlet of one of the receiving funnels 2. The outlet of one of the receiving funnels 2 corresponds to the inlet of the horizontally arranged magnetic conveying mechanism 3, the outlet of the magnetic conveying mechanism 3 corresponds to the inlet of the other receiving funnel 2, and the outlet of the other receiving funnel 2 corresponds to the electrostatic platform of the electrostatic mechanism 4.

[0027] See Figure 2 The support platform 5 includes a horizontal bearing platform 5-1 and a vertical support plate 5-2. The heating barrel 1, two receiving funnels 2 and the magnetic transmission mechanism 3 are fixedly installed on the vertical support plate 5-2 by angle brackets. The electric shock mechanism 4 is fixedly installed on the horizontal bearing platform 5-1, and an insulating plate 5-3 is provided between the two.

[0028] See Figure 4 and Figure 5 The heating tank 1 includes a cylindrical cover 1-1, a tank body 1-2, and several heating elements. The cylindrical cover 1-1 is fixedly connected to the opening at the top of the tank body 1-2 via a flange. A spiral channel 1-2-1 is formed along the center line of the inner wall of the tank body 1-2. The inlet of the spiral channel 1-2-1 is located at the upper end of the tank body 1-2, and the outlet of the spiral channel 1-2-1 is located at the lower end of the tank body 1-2. A catalyst is sputtered on the inner wall of the spiral channel 1-2-1. Through contact between the catalyst and the plastic particles, and under heating, the plastic particles undergo a catalytic reaction to generate carbon powder. Several heating elements are installed axially from top to bottom inside the tank body 1-2 to heat the plastic particles.

[0029] Furthermore, the cylindrical cover 1-1 has a hemispherical shell structure, and a feed inlet is opened on the cylindrical cover 1-1, which corresponds to the feed inlet at the top of the spiral channel 1-2-1, ensuring that the plastic particles can accurately enter the spiral channel 1-2-1.

[0030] Furthermore, the catalyst is an iron-cobalt bimetallic catalyst supported on Al2O3.

[0031] Furthermore, the number of heating elements installed from top to bottom gradually increases to achieve gradient heating of the raw materials. The heating temperature of the heating elements only needs to be 700K to 800K, which reduces energy consumption and increases yield.

[0032] In this application, the transport channel for plastic particles is designed as a spiral structure. On the one hand, this reduces the volume of the heating barrel 1, increases the length of the plastic particle transport channel and the transport time, and ensures that the plastic particles can fully contact the catalyst and achieve carbonization to form carbon powder under sufficient heating temperature and heating time. On the other hand, the heating element is located inside the barrel 1-2, which means that the heating element is completely within the area enclosed by the spiral channel 1-2-1, ensuring the uniformity of heating of the plastic particles. At the same time, due to the gradient heating of the heating element, the carbonization rate of the plastic particles is further guaranteed.

[0033] See Figure 2 The magnetic transmission mechanism 3 includes a conveyor belt 3-1 with magnets, a drive gear 3-2, a tensioning wheel 3-3, and a drive motor. The drive gear 3-2 and the tensioning wheel 3-3 are horizontally rotatably mounted on a vertical support plate 5-2. The conveyor belt 3-1 is fitted onto the drive gear 3-2 and the tensioning wheel 3-3. The output end of the drive motor is connected to the drive gear 3-2 to realize the rotation of the drive gear 3-2.

[0034] As the plastic granules are slowly transported within the spiral channel 1-2-1, they rub against the inner wall of the channel, causing the catalyst to break off and fall off. When the conveyor belt 3-1 is driven by the drive gear 3-2, it transports the mixture of carbon powder and catalyst from the feed end to the discharge end. At the discharge end, the present application uses a magnet on the conveyor belt 3-1 to adsorb the catalyst debris, while the carbon powder falls into the receiving funnel 2 due to gravity, thereby achieving the separation of carbon powder and catalyst, filtering the carbon powder, and ensuring the purity of the carbon powder.

[0035] See Figure 2 The electric shock mechanism 4 includes two sets of clamping components, a conductive film 4-1, and two electrodes 4-2. The two sets of clamping components are arranged opposite to each other and clamp and tension both ends of the conductive film 4-1. The two electrodes 4-2 are respectively arranged on the outside of the two sets of clamping components and are respectively fixedly connected to the ends of the conductive film 4-1.

[0036] Furthermore, each clamping assembly includes a C-clamp 4-3, two graphite conductive electrode plates 4-4, a ceramic bolt 4-5, and a ceramic nut 4-6. The two graphite conductive electrode plates 4-4 are arranged vertically opposite each other inside the C-clamp 4-3, clamping the end of the conductive film 4-1. The ceramic bolt 4-5 is inserted into the C-clamp 4-3 and is located at the upper end of the two graphite conductive electrode plates 4-4. The ceramic nut 4-6 is screwed onto the ceramic bolt 4-5 and abuts against the graphite conductive electrode plate 4-4, thereby clamping the conductive film 4-1.

[0037] The conductive film 4-1 serves as an electric shock platform. By applying current of 220V to 380V to the electrode 4-2, the conductive film 4-1 conducts the voltage to the carbon powder, thereby converting the carbon powder into graphene. The entire electric shock component is encased in a ceramic shell to enhance its insulation performance and safety.

[0038] The following further explains the working process of the present invention to further demonstrate its working principle and advantages:

[0039] Waste plastic granules enter the spiral channel 1-2-1 inside the barrel 1-2 through the feed port on the cylindrical cover 1-1. The waste plastic granules react with the catalyst on the inner wall of the spiral channel 1-2-1 under the heating of the heating element, causing the waste plastic granules to be fully carbonized to form carbon powder. Then, the carbon powder flows through the receiving funnel 2 to the conveyor belt 3-1. Through the conveying and magnetic attraction of the conveyor belt 3-1, the carbon powder and the catalyst are separated. The filtered carbon powder flows through the receiving funnel 2 to the conductive film 4-1. By applying voltage to the electrodes 4-2 on both sides of the conductive film 4-1, the carbon powder is further reacted to become graphene. The whole process realizes the conversion of waste plastic granules into graphene.

[0040] This application first converts plastic particles into carbon powder using a heating tank and a catalyst within the tank, and then converts the carbon powder into graphene using electric shock. Although this adds a step of converting plastic particles into carbon powder compared to Joule flash evaporation technology, it does not place high demands on the heating temperature of the plastic particles or the conversion environment, meaning it can be achieved without oxygen isolation, thus reducing energy consumption and correspondingly increasing the graphene yield. Furthermore, this application does not have requirements on the type of plastic, making it more adaptable than Joule flash evaporation technology, which can only convert paint-based plastics. This reduces the need for initial screening and filtration of plastic types or post-conversion screening of graphene, thus reducing the number of process steps.

[0041] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. An apparatus for preparing graphene from waste plastics based on a carbonization electrostatic method, characterized in that: It includes a heating barrel (1), two receiving funnels (2), a magnetic conveying mechanism (3), an electric shock mechanism (4), and a support platform (5). The heating barrel (1) is used to carbonize waste plastic particles. The receiving funnels (2) are used to guide the aggregation and flow of carbon powder. The magnetic conveying mechanism (3) is used to separate carbon powder from the catalyst. The electric shock mechanism (4) is used to convert carbon powder. The heating barrel (1), two receiving funnels (2), magnetic conveying mechanism (3), and electric shock mechanism (4) are respectively fixedly installed on the support platform (5). The outlet of the heating barrel (1) is connected to the inlet of one of the receiving funnels (2). The outlet of one of the receiving funnels (2) corresponds to the inlet of the horizontally arranged magnetic conveying mechanism (3). The outlet of the magnetic conveying mechanism (3) corresponds to the inlet of the other receiving funnel (2). The outlet of the other receiving funnel (2) corresponds to the electric shock platform of the electric shock mechanism (4). The heating tank (1) includes a tank body (1-2), and a spiral channel (1-2-1) is opened along the center line of the inner wall of the tank body (1-2). A catalyst is sputtered on the inner wall of the spiral channel (1-2-1). The electric shock mechanism (4) includes two sets of clamping components, a conductive film (4-1) and two electrodes (4-2); the two sets of clamping components are arranged opposite to each other and clamp and tension the two ends of the conductive film (4-1); the two electrodes (4-2) are respectively arranged on the outside of the two sets of clamping components and are respectively fixedly connected to the ends of the conductive film (4-1). Each clamping assembly includes a C-clamp (4-3), two graphite conductive electrode plates (4-4), a ceramic bolt (4-5), and a ceramic nut (4-6). The two graphite conductive electrode plates (4-4) are arranged vertically opposite each other in the C-clamp (4-3) and clamp the end of the conductive film (4-1). The ceramic bolt (4-5) is inserted into the C-clamp (4-3) and is located at the upper end of the two graphite conductive electrode plates (4-4). The ceramic nut (4-6) is screwed onto the ceramic bolt (4-5) and abuts against the graphite conductive electrode plate (4-4) to clamp the conductive film (4-1).

2. The apparatus for preparing graphene from waste plastics based on the carbonization electrostatic method according to claim 1, characterized in that: The support platform (5) includes a horizontal bearing platform (5-1) and a vertical support plate (5-2). The heating barrel (1), two receiving funnels (2) and magnetic transmission mechanism (3) are fixedly installed on the vertical support plate (5-2) by angle brackets. The electric shock mechanism (4) is fixedly installed on the horizontal bearing platform (5-1), and an insulating plate (5-3) is provided between the two.

3. The apparatus for preparing graphene from waste plastics based on the carbonization electrostatic method according to claim 1, characterized in that: The heating barrel (1) also includes a cylindrical cover (1-1) and several heating elements. The cylindrical cover (1-1) is fixedly connected to the opening end of the top of the barrel body (1-2) by a flange. The feed inlet of the spiral channel (1-2-1) is located at the upper end of the barrel body (1-2), and the discharge outlet of the spiral channel (1-2-1) is located at the lower end of the barrel body (1-2). The feed inlet on the cylindrical cover (1-1) corresponds to the feed inlet at the upper end of the spiral channel (1-2-1). Several heating elements are installed axially from top to bottom inside the barrel body (1-2) to realize the heating of plastic particles.

4. The apparatus for preparing graphene from waste plastics based on the carbonization electrostatic method according to claim 3, characterized in that: The catalyst is an iron-cobalt bimetallic catalyst supported on Al2O3.

5. The apparatus for preparing graphene from waste plastics based on the carbonization electrostatic method according to claim 3, characterized in that: The number of heating elements installed from top to bottom gradually increases to achieve gradient heating of the raw materials.

6. The apparatus for preparing graphene from waste plastics based on the carbonization electrostatic method according to claim 1, characterized in that: The magnetic transmission mechanism (3) includes a conveyor belt (3-1) with magnets, a drive gear (3-2), a tensioning wheel (3-3), and a drive motor; the drive gear (3-2) and the tensioning wheel (3-3) are horizontally rotatably mounted on a vertical support plate (5-2), the conveyor belt (3-1) is fitted onto the drive gear (3-2) and the tensioning wheel (3-3), and the output end of the drive motor is connected to the drive gear (3-2) to realize the rotation of the drive gear (3-2).

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