A single-walled carbon nanotube CVD production device with recyclable reaction gas

Abstract

This invention provides a single-walled carbon nanotube CVD production apparatus with recyclable reaction gas. It includes a sample feeding mechanism, a reactor, a connecting pipe, a collector, a fan, an exhaust pipe, and a chimney connected in sequence, as well as a circulation pipeline connecting the sample feeding mechanism and the exhaust pipe. Control valves are installed on both the exhaust pipe and the circulation pipeline. The sample feeding mechanism includes an inlet pipe, a feed pipe, a preheater, and an atomizer. The inlet pipe is connected to the reactor, the preheater is located on the inlet pipe, the feed pipe is connected to the inlet pipe between the preheater and the reactor, and the atomizer is located inside the reactor and connected to the inlet pipe. This invention achieves the recycling of reaction gas through a gas circulation pipeline; furthermore, the use of two feed chamber doors ensures continuous production, significantly improves production efficiency and convenience, and greatly reduces production costs.

Description

Technical Field

[0001] This invention belongs to the field of single-walled carbon nanotube preparation technology, and particularly relates to a single-walled carbon nanotube CVD production device with recyclable reaction gas. Background Technology

[0002] Carbon nanotubes (CNTs) have become one of the most popular research topics in materials science due to their unique structure and the resulting excellent properties. Their outstanding mechanical, electrical, and thermal properties make them a promising candidate for applications in energy storage and conversion, display technology, electronic devices, optoelectronics, biomedicine, and high-performance composite materials.

[0003] However, achieving widespread application of carbon nanotubes in high-end fields remains a core challenge, particularly in their controllable synthesis. Single-walled carbon nanotubes (SWNTs) can be considered as one-dimensional tubular structures formed by rolling up a single layer of graphene along a specific direction, and their properties are highly dependent on their diameter and chirality. Currently, the main methods for preparing carbon nanotubes include chemical vapor deposition (CVD), arc deposition, and laser ablation. Among these, CVD is considered to have the greatest industrialization potential due to its low cost, ease of operation, and suitability for large-scale production. In recent years, fluidized bed-based CVD technology has achieved annual production of thousands of tons of single-walled carbon nanotubes. Compared to other methods, CVD offers greater freedom in catalyst design, growth parameter optimization, and substrate selection, enabling more precise control over the growth process of carbon nanotubes. Therefore, CVD is currently the most effective method for achieving controllable synthesis of carbon nanotube structures and a key technology for promoting their industrial application.

[0004] However, existing CVD methods face two main problems in practical applications. On the one hand, how to improve the process and catalyst to increase the yield and quality of single-walled carbon nanotubes; on the other hand, how to further reduce the cost of producing single-walled carbon nanotubes while achieving high-yield and high-quality production, so as to promote the industrialization of single-walled carbon nanotubes. Utility Model Content

[0005] This invention provides a single-walled carbon nanotube CVD production device with recyclable reaction gas, which can effectively solve the above problems.

[0006] This utility model is implemented as follows:

[0007] A single-walled carbon nanotube CVD production apparatus with recyclable reaction gas includes a sample feeding mechanism, a reactor, a connecting pipe, a collector, a blower, an exhaust pipe, and a chimney connected in sequence, as well as a circulation pipeline connecting the sample feeding mechanism and the exhaust pipe. Control valves are respectively installed on the exhaust pipe and the circulation pipeline. The sample feeding mechanism includes an inlet pipe, a feed pipe, a preheater, and an atomizer. The inlet pipe is connected to the reactor, the preheater is located on the inlet pipe, the feed pipe is connected to the inlet pipe between the preheater and the reactor, and the atomizer is located inside the reactor and connected to the inlet pipe.

[0008] The reactor includes a reaction tube, a heater, an insulation layer, and a shell arranged from the inside out. The reaction tube is a circular graphite tube, and the insulation layer is a multi-layer ceramic fiber layer. A reflective layer is provided inside or between the insulation layers.

[0009] The connecting pipe is equipped with cooling water and air-cooling nozzles on its outer periphery. The air-cooling nozzles blow gas into the connecting pipe from the upstream side to the downstream side at a 45° angle. A viewing window is provided at the end of the connecting pipe.

[0010] The reactor is vertically arranged, and the gas inlet pipe is connected to the lower end of the reaction tube.

[0011] The collector is equipped with a switching valve, a differential pressure gauge, a filter bag, and a material collection hopper door. The switching valve is located between the collector and the reactor. The differential pressure gauge is located outside the collector and connected to both ends of the collector. The filter bag is located inside the collector. The material collection hopper door is located on the side of the collector.

[0012] The collectors are connected in parallel, and each is equipped with a switching valve to switch the collection.

[0013] One end of the circulation pipeline is connected to the air inlet pipe at the upstream end of the preheater.

[0014] One end of the circulation pipeline is connected to the air inlet pipe between the preheater and the feed pipe, and a second preheater is provided on the circulation pipeline.

[0015] The diameter of the air inlet port of the circulation pipeline is larger than the diameter of the air outlet port.

[0016] A pressure relief pipeline is provided between the circulation pipeline and the chimney, and a pressure relief valve is provided on the pressure relief pipeline.

[0017] The beneficial effects of this utility model are:

[0018] This invention achieves the recycling of reaction gases through a gas circulation pipeline; in addition, the use of two material receiving chamber doors ensures the continuity of production, significantly improves production efficiency and convenience, and greatly reduces production costs.

[0019] Using circular graphite tubes as reaction tubes ensures that the generated heat can be rapidly transferred to the inside of the reactor, thus achieving efficient heating. The graphite tubes enable the large-volume reactor to maintain a stable temperature, which is beneficial for the catalyst to function more efficiently, thereby producing high-quality single-walled carbon nanotubes. This also increases the yield of single-walled carbon nanotubes, enabling mass production.

[0020] By adopting a bottom-feed method, the gas and reaction solution are introduced from the bottom of the reactor, which improves the airflow stability of the gas and extends the growth time of single-walled carbon nanotubes, thereby achieving high-purity growth of single-walled carbon nanotubes and effectively increasing the yield of high-quality single-walled carbon nanotubes. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of a single-walled carbon nanotube CVD production device with recyclable reaction gas according to this utility model;

[0023] Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle;

[0024] Figure 3 This is a SEM image of single-walled carbon nanotubes produced by a single-walled carbon nanotube CVD production device with recyclable reaction gas according to this utility model.

[0025] Figure 4 This is the Raman spectrum of single-walled carbon nanotubes produced by a CVD production device for single-walled carbon nanotubes with recyclable reaction gas according to this utility model.

[0026] Figure label:

[0027] Sample injection mechanism 1; air inlet pipe 11; feed pipe 12; preheater 13; atomizer 14; reactor 2; reaction tube 21; heater 22; insulation layer 23; shell 24; connecting pipe 3; cooling water 31; air-cooled nozzle 32; viewing window 33; collector 4; switching valve 41; differential pressure gauge 42; filter bag 43; material receiving hopper door 44; fan 5; exhaust pipe 6; control valve 61; chimney 7; circulation pipeline 8; second preheater 81; pressure relief pipeline 82; pressure relief valve 83. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to represent selected embodiments of this utility model.

[0029] In the description of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In the description of this utility model, the terms "upper", "middle", "side", "side", "upper side", "end", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] Reference Figure 1-2 As shown, a single-walled carbon nanotube CVD production apparatus with recyclable reaction gas includes a sample feeding mechanism 1, a reactor 2, a connecting pipe 3, a collector 4, a blower 5, an exhaust pipe 6, and a chimney 7 connected in sequence, and a circulation pipeline 8 connecting the sample feeding mechanism 1 and the exhaust pipe 6. Control valves 61 are respectively installed on the exhaust pipe 6 and the circulation pipeline 8. The sample feeding mechanism 1 includes an inlet pipe 11, a feed pipe 12, a preheater 13, and an atomizer 14. The atomizer 14 converts the liquid precursor into micron or nanometer-sized droplets, improving reaction efficiency and product quality. The inlet pipe 11 is connected to the reactor 2, and materials and gases extend into the reactor 2 through the same pipe. The preheater 13 is located on the inlet pipe 11, the feed pipe 12 is connected to the inlet pipe 11 between the preheater 13 and the reactor 2, and the atomizer 14 is located inside the reactor 2 and connected to the inlet pipe 11.

[0032] Preheating maintains the stability of the reaction temperature, promotes carbon source decomposition, improves reaction efficiency, and reduces side reactions and impurities.

[0033] Furthermore, the reactor 2 includes a reaction tube 21, a heater 22, an insulation layer 23, and a shell 24 arranged from the inside out, providing a stable high-temperature growth environment for single-walled carbon nanotubes. The reaction tube 21 is a circular graphite tube, which has excellent thermal conductivity, ensuring that the generated heat can be rapidly transferred to the inside of the reactor, thereby achieving efficient heating. The graphite tube effectively overcomes the problem of temperature fluctuations in large-volume reactors, not only improving the utilization efficiency of the catalyst but also significantly increasing the yield of single-walled carbon nanotubes. The insulation layer 23 is a multi-layer ceramic fiber layer. A reflective layer is provided inside or between the insulation layers 23 to further maintain the temperature of the reaction zone and prevent heat loss.

[0034] Furthermore, the outer periphery of the connecting pipe 3 is provided with cooling water 31 and air-cooling nozzle 32. The air-cooling nozzle 32 blows gas into the connecting pipe 3 at a 45° angle from the upstream side to the downstream side. On the one hand, it can rapidly reduce the temperature of the product, and on the other hand, it can transport the product to the collection end. The end of the connecting pipe 3 is provided with a viewing window 33, through which the production status of the product in the reaction device can be observed.

[0035] Furthermore, the reactor 2 is vertically arranged, and the gas inlet pipe 11 is connected to the lower end of the reaction pipe 21.

[0036] Furthermore, the collector 4 is equipped with a switching valve 41, a differential pressure gauge 42, a filter bag 43, and a material collection chamber door 44. The switching valve 41 is located between the collector 4 and the reactor. The differential pressure gauge 42 is located outside the collector 4 and is connected to both ends of the collector 4. The filter bag 43 is located inside the collector 4. The material collection chamber door 44 is located on the side of the collector 4.

[0037] When the reading on differential pressure gauge 42 is too high, it indicates that the feed bin is full.

[0038] Furthermore, two collectors 4 are connected in parallel, each equipped with a switching valve 41 to switch between collection points. The two parallel material collection bins can be switched between each other via the switching valve 41, facilitating material collection without affecting the production process and promoting continuous and efficient production.

[0039] Furthermore, one end of the circulation pipeline 8 is connected to the air inlet pipe 11 at the upstream end of the preheater 13.

[0040] Furthermore, one end of the circulation pipeline 8 is connected to the air inlet pipe 11 between the preheater 13 and the feed pipe 12, and a second preheater 81 is provided on the circulation pipeline 8.

[0041] Furthermore, the diameter of the air inlet port of the circulation pipeline 8 is larger than the diameter of the air outlet port.

[0042] Furthermore, a pressure relief pipe 82 is provided between the circulation pipe 8 and the chimney 7, and a pressure relief valve 83 is provided on the pressure relief pipe 82.

[0043] The valve outlet at the bottom of collector 4 is connected to fan 5 via a pipe. The outlet of fan 5 is divided into three pipes: one leads to circulation pipe 8 for gas recycling and continuous production of single-walled carbon nanotubes; the other leads to exhaust pipe 6, which connects to chimney 7. In case of equipment failure and maintenance, the reaction gas inside the equipment is discharged into chimney 7 for exhaust gas treatment; and the third leads to pressure relief pipe 82, which releases a portion of the gas when the pressure is too high, and delivers the gas at the required pressure to circulation pipe 8 for utilization. If the circulating gas pressure is insufficient, it can be supplemented through inlet pipe 11 to achieve the required gas volume.

[0044] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A single-walled carbon nanotube CVD production apparatus with recyclable reaction gas, characterized in that, The system includes a sample injection mechanism, a reactor, a connecting pipe, a collector, a blower, an exhaust pipe, and a chimney connected in sequence, as well as a circulation pipeline connecting the sample injection mechanism and the exhaust pipe. Control valves are respectively installed on the exhaust pipe and the circulation pipeline. The sample injection mechanism includes an air inlet pipe, a feed pipe, a preheater, and an atomizer. The air inlet pipe is connected to the reactor. The preheater is located on the air inlet pipe. The feed pipe is connected to the air inlet pipe between the preheater and the reactor. The atomizer is located inside the reactor and connected to the air inlet pipe.

2. The single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 1, characterized in that, The reactor includes a reaction tube, a heater, an insulation layer, and a shell arranged from the inside out. The reaction tube is a circular graphite tube, and the insulation layer is a multi-layer ceramic fiber layer. A reflective layer is provided inside or between the insulation layers.

3. The single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 1, characterized in that, The connecting pipe is equipped with cooling water and air-cooling nozzles on its outer periphery. The air-cooling nozzles blow gas into the connecting pipe from the upstream side to the downstream side at a 45° angle. A viewing window is provided at the end of the connecting pipe.

4. A single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 1 or 2, characterized in that, The reactor is vertically arranged, and the gas inlet pipe is connected to the lower end of the reaction tube.

5. The single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 1, characterized in that, The collector is equipped with a switching valve, a differential pressure gauge, a filter bag, and a material collection hopper door. The switching valve is located between the collector and the reactor. The differential pressure gauge is located outside the collector and connected to both ends of the collector. The filter bag is located inside the collector. The material collection hopper door is located on the side of the collector.

6. The single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 5, characterized in that, The collectors are connected in parallel, and each is equipped with a switching valve to switch the collection.

7. The single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 1, characterized in that, One end of the circulation pipeline is connected to the air inlet pipe at the upstream end of the preheater.

8. The single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 1, characterized in that, One end of the circulation pipeline is connected to the air inlet pipe between the preheater and the feed pipe, and a second preheater is provided on the circulation pipeline.

9. A single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 1, 7, or 8, characterized in that, The diameter of the air inlet port of the circulation pipeline is larger than the diameter of the air outlet port.

10. The single-walled carbon nanotube CVD production apparatus with recyclable reaction gas according to claim 9, characterized in that, A pressure relief pipeline is provided between the circulation pipeline and the chimney, and a pressure relief valve is provided on the pressure relief pipeline.

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