Arc plasma generator and preparation equipment of single-walled carbon nanotube
By adopting the design of surrounding cooling parts in the arc plasma generator, the emitter maintains a stable arc at high temperature, solving the problem of discontinuous catalyst gasification in single-wall nanocarbon tube production, and achieving continuous single-wall carbon nanotubes and efficient production.
Patent Information
- Application Number
- CN202411263019.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2024-12-10
AI Technical Summary
In the existing equipment for preparing single-wall carbon tubes with arc discharge method, it is difficult to maintain a stable arc between the tungsten needle and the catalyst, resulting in discontinuous catalyst vaporization, affecting the continuous production of single-wall carbon nanotubes.
An arc plasma generator is designed, using a cooling section surrounding the emitter, including solid and liquid cooling medium channels, and a high-temperature heat-resistant medium and graphite sealing ring to ensure that the emitter always maintains a stable arc under a high temperature environment.
Continuous preparation of single-wall carbon nanotubes is realized, and the catalyst is vaporized through stable arcing to form nano-level droplets. The feed gas is dehydrogenated at high temperatures. The product adheres to the catalyst droplets to form single-wall carbon nanotubes. , improves the continuity and efficiency of production.
Smart Images
Figure CN119110474A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of single-walled carbon nanotube production and manufacturing, and in particular to an arc plasma generator for producing single-walled carbon nanotubes and single-walled carbon nanotube preparation equipment. Background Art
[0002] The preparation of single-walled carbon nanotubes using arc discharge is one of the commonly used preparation methods for single-walled carbon nanotubes. Its working principle is: a carbon-containing gas is introduced into a vacuum container, a transition metal is used as a catalyst to form a receiving electrode, a tungsten needle is used as an anode, and the argon gas is broken down and ionized by the high voltage between the cathode and anode to form a stable arc. During the arc discharge process, the metal catalyst in the receiving electrode is vaporized and forms nano-scale droplets in the reaction container. The carbon-containing gas attaches to the metal droplets under the high temperature environment in the reaction container and dehydrogenates, thereby producing single-walled carbon nanotubes.
[0003] In the production equipment for preparing single-walled carbon nanotubes by arc discharge method, a reliable and stable arc needs to be generated between the tungsten needle of the arc plasma generator and the catalyst to continuously gasify the catalyst to achieve continuous production of single-walled carbon nanotubes. The temperature in the reactor can reach up to 3000°C. Therefore, designing an arc plasma generator with a reasonable structure to adapt to the ultra-high temperature in the reactor has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention
[0004] To this end, the present invention proposes an arc plasma generator capable of realizing continuous production of single-walled carbon nanotubes and a single-walled carbon nanotube preparation device.
[0005] In view of the above technical problems, the present invention provides the following technical solutions:
[0006] An arc plasma generator comprises a generator body; an emitter installed inside the generator body, the emitter comprising a conductive tube extending along a first direction and an emission nozzle located at the end of the conductive tube; the conductive tube is electrically connected to the arc generator, and a gas channel is provided in the conductive tube and the emission nozzle for supplying a protective gas; and a cooling portion arranged around the emitter for cooling the emitter.
[0007] In some embodiments of the present invention, the cooling part includes a solid cooling medium channel surrounding the outside of the emitter, and a liquid cooling medium channel surrounding the outside of the solid cooling medium channel, the solid cooling medium channel is connected to the emitter, and the liquid cooling medium channel is isolated from the emitter by the solid cooling medium channel.
[0008] In some embodiments of the present invention, a liquid cooling medium inlet and a liquid cooling medium outlet are provided on the end face of the generator body on the side away from the emission nozzle, the liquid cooling medium channel is divided by a partition into a first channel connected to the liquid cooling medium inlet and a second channel connected to the liquid cooling medium outlet, and a connecting hole is provided on the side of the partition close to the emission nozzle.
[0009] In some embodiments of the present invention, the solid cooling medium channel is filled with a high temperature resistant heat conductive medium.
[0010] In some embodiments of the present invention, a side of the conductive tube body close to the emission nozzle is sealed and connected to the generator body via a sealing portion therebetween.
[0011] In some embodiments of the present invention, the sealing portion includes a sealing groove provided on the inner wall of the generator body and a graphite sealing ring provided in the sealing groove.
[0012] In some embodiments of the present invention, a side of the conductive tube away from the emission nozzle is connected to the generator body via a threaded fastening portion.
[0013] In some embodiments of the present invention, the end of the emission nozzle is in the shape of an inverted truncated cone, and the emission nozzle is provided with spray holes evenly distributed around the axis on the side of the truncated cone-shaped end.
[0014] The present invention also provides a single-wall carbon nanotube preparation device, including a main reactor and an arc plasma generator and a catalyst assembly installed on the main reactor and arranged at intervals, wherein the arc plasma generator adopts the arc plasma generator.
[0015] In some embodiments of the present invention, the arc plasma generator is located on the upper side of the main reactor, and the extension direction of the emitter has an angle other than 0° with the horizontal direction, and the catalyst assembly is located on the lower side of the main reactor, and the catalyst assembly includes a solid metal catalyst, and the upper surface of the solid metal catalyst extends in the horizontal direction.
[0016] The technical solution of the present invention has the following technical effects compared with the prior art:
[0017] The present invention provides an arc plasma generator that generates a stable arc between the emitter of the arc plasma generator and the surface of a solid metal catalyst during the preparation of single-walled carbon nanotubes, so that the solid metal catalyst is vaporized and enters the catalyst vaporization chamber to form nanometer-level droplets; the feed gas enters the catalyst vaporization chamber and is cracked and dehydrogenated in a high-temperature environment, and the reaction product adheres to the catalyst droplets to complete growth and finally forms single-walled carbon nanotubes and is discharged. Among them, since the emitter is surrounded by a cooling part, the cooling effect of the cooling part can keep the emitter in a controllable temperature field at all times, so that a relatively stable arc can always be generated between the emitter and the catalyst surface, thereby achieving continuous preparation of single-walled carbon nanotubes. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, which will help to understand the objects and advantages of the present invention, wherein:
[0019] Figure 1 It is a structural schematic diagram of a specific implementation mode of the arc plasma generator of the present invention;
[0020] Figure 2 It is a partial enlarged view of a specific embodiment of the arc plasma generator of the present invention;
[0021] Figure 3 for Figure 1 Sectional view of AA in the middle;
[0022] Figure 4 It is a structural schematic diagram of a specific embodiment of the single-walled carbon nanotube preparation device of the present invention. DETAILED DESCRIPTION
[0023] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0024] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0026] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0027] like Figure 1 , Figure 2 The figure shows a specific embodiment of an arc plasma generator 20 for producing single-walled carbon nanotubes provided by the present invention. The arc plasma generator 20 comprises a generator body 21, an emitter 22 installed inside the generator body 21, and a cooling part 23 surrounding the emitter 22 and used for cooling the emitter 22.
[0028] The emitter 22 includes a conductive tube body 221 extending along a first direction and an emitter nozzle 222 located at the end of the conductive tube body 221; the emitter nozzle 222 is made of metal tungsten, and the conductive tube body 221 is made of metal copper. The emitter nozzle 222 is plugged into the end of the conductive tube body 221, and the conductive tube body 221 is electrically connected to an arc generator (not shown in the figure); a gas channel 22a is provided in the conductive tube body 221 and the emitter nozzle 222 for supplying a protective gas. Specifically, the protective gas is argon, which is broken down and ionized by the high voltage between the cathode and anode to form a stable arc.
[0029] When the arc plasma generator 20 is used to prepare single-walled carbon nanotubes, the arc generator is controlled to be turned on so that a stable arc is generated between the emitter 22 of the arc plasma generator 20 and the surface of the solid metal catalyst 32. Figure 4 As shown, the solid metal catalyst 32 is gasified and enters the catalyst gasification chamber 10a to form nano-scale droplets; the feed gas (such as carbon-containing organic matter such as methane) enters the catalyst gasification chamber 10a and is cracked and dehydrogenated in a high-temperature environment, and the reaction product is attached to the catalyst 32 droplets to complete growth and finally form single-walled carbon nanotubes and are discharged. Among them, since the emitter 22 is surrounded by the cooling part 23, the cooling effect of the cooling part 23 can make the emitter 22 always in a controllable temperature field, so that a relatively stable arc can always be generated between the emitter 22 and the surface of the catalyst 32, thereby realizing the continuous preparation of single-walled carbon nanotubes.
[0030] Specifically, in an optional implementation manner, Figure 2 As shown, the cooling part 23 includes a solid cooling medium channel 23a surrounding the outside of the emitter 22, and a liquid cooling medium channel 23b surrounding the outside of the solid cooling medium channel 23a. The solid cooling medium channel 23a is connected to the emitter 22, and the liquid cooling medium channel 23b is isolated from the emitter 22 by the solid cooling medium channel 23a. More specifically, the solid cooling medium channel 23a is filled with a high-temperature resistant solid heat-conducting medium such as heat-conducting graphite to achieve heat exchange with the emitter 22. The cooling part 23 achieves cooling of the emitter 22 through the solid cooling medium channel 23a and the liquid cooling medium channel 23b, and the cooling effect is good. At the same time, isolating the liquid cooling medium channel 23b from the emitter 22 by the solid cooling medium channel 23a can avoid the safety hazard caused by the liquid in the liquid cooling medium channel contacting with the emitter 22 and being ionized.
[0031] Among them, Figure 3 As shown, the generator body 21 is formed in the form of a double-layer annular jacket, wherein the inner annular jacket 211 is open on both sides, and one end portion is provided with a connecting sleeve portion 2111 for cooperating with the conductive tube body 221, and other areas of the inner annular jacket 211 are spaced apart from the conductive tube body 221 to form the solid cooling medium channel 23a.
[0032] The outer annular sleeve 212 of the generator body 21 is in the form of an open side and a closed side, and a liquid cooling medium channel 23b is formed between the inner annular sleeve 211 and the outer annular sleeve 212, wherein the liquid cooling medium channel 23b is divided into at least two channels by a partition 213, and the two channels are connected by a connecting hole, wherein the connecting hole is provided on the side of the partition 213 close to the emission nozzle 222.
[0033] Specifically, in an optional embodiment, the end surface of the generator body 21 away from the emission nozzle 222 is provided with a liquid cooling medium inlet and a liquid cooling medium outlet. Figure 3 As shown, the liquid cooling medium channel 23b is divided into a first channel 23b1 and a second channel 23b2 by a partition 213, the first channel 23b1 is connected to the liquid cooling medium inlet, and the second channel 23b2 is connected to the liquid cooling medium outlet.
[0034] Specifically, in an optional implementation manner, Figure 2As shown, the side of the conductive tube 221 close to the emission nozzle 222 is sealed and connected to the generator body 21 through a sealing portion 24 therebetween. That is, the conductive tube 221 is sealed and connected to the connecting sleeve 2111 in the generator body 21 to prevent the solid cooling medium channel 23a from contacting the outside and causing cold to leak out. The sealing portion 24 includes a sealing groove arranged on the inner wall of the generator body 21 and a graphite sealing ring arranged in the sealing groove.
[0035] Specifically, in an optional implementation, the side of the conductive tube 221 away from the emission nozzle 222 is connected to the generator body 21 via a threaded fastening portion 25 .
[0036] The end of the emission nozzle 222 is in an inverted truncated cone shape, and the emission nozzle 222 is provided with spray holes 222a evenly distributed around its axis on the side of its truncated cone-shaped end. The argon gas is sprayed along the gas channel in the conductive tube body 221 and the emission nozzle 222 and through the spray holes 222a to between the emission nozzle 222 and the surface of the catalyst 32.
[0037] The present invention also provides a specific embodiment of a single-walled carbon nanotube preparation device, such as Figure 4 As shown, the preparation equipment includes a main reactor 10, the main reactor 10 includes a catalyst gasification chamber 10a, and the main reactor 10 is provided with the arc plasma generator 20 and the catalyst assembly 30. The generator body 21 of the arc plasma generator 20 is fixedly mounted on the main reactor 10, and the emitter 22 has a side of the nozzle 222a extending into the catalyst gasification chamber 10a; the catalyst assembly 30 includes a catalyst receiving portion 31 for accommodating a solid catalyst 32, and the catalyst receiving portion 31 extends into the inner side of the catalyst gasification chamber 10a. The catalyst assembly 30 also includes a receiving stage 33 connected to the catalyst receiving portion 31, and the receiving stage 33 passes through the catalyst receiving portion 31 and is connected to the solid catalyst 32.
[0038] A stable electric arc is generated between the arc plasma generator 20 and the catalyst assembly 30, so that the metal catalyst 32 in the catalyst assembly 30 is vaporized and enters the catalyst gasification chamber 10a of the main reactor 10 to form nanometer-scale droplets; the feed gas (such as methane and other carbon-containing organic matter) enters the catalyst gasification chamber 10a along the feed port 13 of the main reactor 10 and is cracked and dehydrogenated in a high-temperature environment, and the reaction product is attached to the catalyst 32 droplets and enters the carbon nanotube generation chamber along the catalyst gasification chamber 10a to complete the growth and finally form single-walled carbon nanotubes and are discharged along the discharge port, thereby realizing the continuous preparation of single-walled carbon nanotubes.
[0039] The arc plasma generator 20 is located on the upper side of the main reactor 10, and the extending direction of the emitter 22 has an angle with the horizontal direction that is not 0°, and the catalyst assembly 30 is located on the lower side of the main reactor 10 and the upper surface of the metal catalyst 32 extends in the horizontal direction. When the arc heats the solid catalyst 32 at high temperature, the high-temperature catalyst 32 liquid will sputter to the surroundings, and the emitter nozzle 222 and the surface of the solid catalyst 32 form a certain angle so that the argon gas blown from the emitter nozzle 222 can quickly blow away the sputtered droplets, thereby preventing the emitter nozzle 222 from being ablated.
[0040] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.
Claims
1. An arc plasma generator, characterized in that: include: Generator body; An emitter installed inside the generator body, the emitter comprising a conductive tube extending along a first direction and an emitter nozzle located at an end of the conductive tube; the conductive tube is electrically connected to the arc generator, and a gas channel is provided in the conductive tube and the emitter nozzle for supplying a protective gas; and a cooling portion arranged around the emitter, for cooling the emitter.
2. An arc plasma generator according to claim 1, characterized in that: The cooling part includes a solid cooling medium channel surrounding the outside of the emitter, and a liquid cooling medium channel surrounding the outside of the solid cooling medium channel, the solid cooling medium channel is connected to the emitter, and the liquid cooling medium channel is isolated from the emitter by the solid cooling medium channel.
3. An arc plasma generator according to claim 2, characterized in that: A liquid cooling medium inlet and a liquid cooling medium outlet are provided on the end surface of the generator body on the side away from the emission nozzle. The liquid cooling medium channel is divided into a first channel connected to the liquid cooling medium inlet and a second channel connected to the liquid cooling medium outlet by a partition. A connecting hole is provided on the side of the partition close to the emission nozzle.
4. The arc plasma generator according to claim 2, characterized in that: The solid cooling medium channel is filled with a high temperature resistant heat conducting medium.
5. The arc plasma generator according to claim 1 The device is characterized in that The side of the conductive tube body close to the emission nozzle is sealed and connected to the generator body via a sealing portion therebetween.
6. The arc plasma generator according to claim 5, characterized in that: The sealing part comprises a sealing groove arranged on the inner wall of the generator body and a graphite sealing ring arranged in the sealing groove.
7. The arc plasma generator according to claim 1, characterized in that: The side of the conductive tube body away from the emission nozzle is connected to the generator body through a threaded fastening portion.
8. The arc plasma generator according to claim 1, characterized in that: The end of the emission nozzle is in the shape of an inverted truncated cone, and the emission nozzle is provided with spray holes evenly distributed around the axis on the side of the truncated cone end.
9. A single-walled carbon nanotube preparation device, characterized in that: include: A main reactor and an arc plasma generator and a catalyst assembly installed on the main reactor and arranged at intervals, wherein the arc plasma generator is the arc plasma generator described in any one of claims 1-8.
10. The single-walled carbon nanotube preparation device according to claim 9, characterized in that: The arc plasma generator is located on the upper side of the main reactor, and the extension direction of the emitter has an angle with the horizontal direction that is not 0°. The catalyst assembly is located on the lower side of the main reactor, and the catalyst assembly includes a solid metal catalyst, and the upper surface of the solid metal catalyst extends in the horizontal direction.