Crucible for high-temperature purification of carbon nanotubes

Abstract

A carbon nano tube high-temperature purification crucible comprises a crucible body and a crucible cover, an opening is formed in the top of the crucible body to form an inlet and outlet through which a carbon nano tube can be conveniently put in and taken out, the crucible cover is detachably assembled in the crucible body, and the crucible cover divides the interior of the crucible body into a purification area on the lower side and a buffer area on the upper side. A plurality of first exhaust holes are uniformly distributed in the crucible cover; and the purification area is communicated with the buffer area through the first exhaust holes. The device effectively solves the problems that an existing crucible is heavy and gasified impurities cannot be thoroughly removed, and meanwhile, the crucible has longer service life and better heat-conducting property, so that the industrial cost and the energy consumption are reduced.

Description

Technical Field

[0001] This utility model relates to the field of crucible technology for high-temperature purification, and in particular to a high-temperature purification crucible for carbon nanotubes. Background Technology

[0002] Carbon nanotubes (CNTs) are tubular nanostructures composed of carbon atoms, exhibiting single-walled or multi-walled morphology. They possess extremely high strength, excellent electrical and thermal conductivity, and typically range in diameter from a few nanometers to tens of nanometers, with lengths reaching the meter level. Due to their unique physical and chemical properties, carbon nanotubes show great application potential in fields such as electronic devices, composite materials, and energy storage. However, the actual production and preparation process of carbon nanotubes often generates impurities such as amorphous carbon and metal catalysts, which severely affect the performance and applications of carbon nanotubes. Therefore, carbon nanotube purification is a crucial step in realizing their applications in electronics, energy, and other fields. Removing these impurities and improving the purity of carbon nanotubes can greatly ensure their reliability and stability in high-performance applications.

[0003] Currently, the mainstream methods for purifying carbon nanotubes include oxidation, acid washing, and high-temperature purification. Oxidation primarily removes amorphous carbon from the nanotubes, while acid washing and high-temperature purification mainly remove impurities such as metals. Acid washing has stringent environmental regulations regarding wastewater treatment and limited metal purification capabilities; therefore, high-temperature purification remains the preferred method for obtaining high-purity carbon nanotubes. In vacuum high-temperature purification, the crucible is a crucial tool, used to hold the carbon nanotubes and withstand the high temperatures. However, traditional crucibles currently fail to adequately address the issue of incomplete removal of vaporized impurities during purification. Furthermore, their bulkiness and limited thermal shock resistance and high-temperature thermal conductivity result in poor purification consistency and low purity of the carbon nanotubes. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a thin, lightweight, convenient carbon nanotube high-temperature purification crucible that facilitates the removal of vaporized impurities, has a long service life, and excellent thermal conductivity.

[0005] To achieve the above objectives, this utility model first proposes a high-temperature purification crucible for carbon nanotubes, including a crucible body and a crucible lid. The top opening of the crucible body forms an inlet and outlet for convenient insertion and removal of carbon nanotubes. The crucible lid is detachably mounted inside the crucible body. The crucible lid divides the crucible body into a lower purification zone and an upper buffer zone. Multiple first exhaust holes are evenly distributed on the crucible lid, and the first exhaust holes connect the purification zone and the buffer zone.

[0006] In this embodiment, an annular stepped groove is provided on the inner wall of the upper side of the crucible body, and the diameter of the crucible cover matches the outer diameter of the annular stepped groove. The crucible cover is installed in the crucible body through the annular stepped groove.

[0007] In this embodiment, the diameter of the first vent hole is 0.5~5.0 mm.

[0008] In this embodiment, the height of the buffer area is 30~100 mm.

[0009] In this embodiment, the crucible body is made of carbon-carbon composite material, and the crucible lid is also made of carbon-carbon composite material.

[0010] In this embodiment, the crucible body has a through hole on the side wall of the buffer area to form a second vent hole, and the bottom of the crucible body has an annular groove that matches the top opening of the crucible body. In the stacked state, the bottom of the upper crucible body is engaged in the top opening of the lower crucible body through the annular groove.

[0011] In this embodiment, the diameter of the second vent hole is 0.5~5.0 mm.

[0012] With the above structure, this utility model has the following advantages:

[0013] 1. The crucible lid of this invention has uniformly spaced vent holes, allowing gaseous impurities generated during the high-temperature purification of carbon nanotubes to be discharged more smoothly through these vent holes. Furthermore, after the crucible lid is installed inside the crucible body, a gap forms a buffer zone between the upper side of the lid and the inlet / outlet of the crucible body. During the vacuum high-temperature purification of carbon nanotubes, this buffer zone serves two purposes: firstly, it acts as a buffer area when large amounts of impurity gas are discharged, reducing leakage and overflow of carbon nanotubes caused by airflow disturbances during vacuuming and impurity gas discharge; secondly, it also serves as a buffer area for some leaked carbon nanotubes, preventing them from directly leaking and spraying into the equipment, thus avoiding short circuits or other circuit damage.

[0014] 2. The crucible body of this utility model can be stacked for use, thereby improving the space utilization of the equipment. Furthermore, the bottom of the crucible body is provided with an annular groove, which makes the stacked crucible body have good overall stability and prevents it from tipping over.

[0015] 3. Both the crucible body and the crucible lid of this utility model are made of carbon-carbon composite material. The crucible body has a bulk density ≥1.3g / cm³. 3 Compared to the existing requirement of ≥1.7g / cm³, 3The graphite crucibles used in this device allow for a thinner and lighter crucible body and lid, with a thickness of 5-8mm. This makes the crucibles easier to handle and transport. Furthermore, the carbon-carbon composite crucibles have higher strength and better thermal shock resistance, enabling them to withstand repeated high-temperature and cooling conditions for a greater number of uses. This effectively extends the crucible's lifespan and reduces solid waste generated by discarded crucibles.

[0016] 4. The crucible body and crucible lid made of carbon-carbon composite material are used in the vacuum high-temperature purification of carbon nanotubes. On the one hand, due to its better thermal conductivity, the thermal conductivity of the crucible is relatively high during the heating and cooling process. The carbon nanotubes in the center and edge areas can be heated and cooled quickly and uniformly, which helps to shorten the process cycle of vacuum high-temperature purification of carbon nanotubes. On the other hand, the carbon-carbon composite material has low density and high porosity, providing more exhaust paths.

[0017] In summary, this device effectively solves the problems of bulky crucibles and incomplete removal of vaporized impurities in existing systems, while also having a longer service life and better thermal conductivity, thereby reducing industrial costs and energy consumption. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the present invention.

[0019] Figure 2 This is a diagram showing the stacked usage state of this utility model.

[0020] In the attached diagram: 1. Crucible body; 2. Purification zone; 3. Crucible lid; 4. First vent; 5. Second vent; 6. Buffer zone; 7. Annular slot. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0023] like Figure 1As shown, a high-temperature purification crucible for carbon nanotubes includes a crucible body 1 and a crucible lid 3. The top opening of the crucible body 1 forms an inlet and outlet for convenient insertion and removal of carbon nanotubes. The crucible lid 3 is detachably mounted on an annular stepped groove on the crucible body 1. Specifically, an annular stepped groove is provided on the inner wall of the upper side of the crucible body 1. The crucible lid 3 is disc-shaped, and the diameter of the crucible lid 3 matches the outer diameter of the annular stepped groove. The crucible lid 3 is installed inside the crucible body 1 through the annular stepped groove, thereby realizing the detachable assembly of the crucible lid 3 and the crucible body 1.

[0024] Furthermore, the crucible lid is evenly provided with multiple through holes to form a first exhaust hole 4; the diameter of the first exhaust hole 4 is 0.5~5.0 mm, preferably 1.5~3 mm. The space between the crucible lid 3 and the bottom of the crucible body 1 forms a closed purification zone 2. A gap is provided between the inlet and outlet of the crucible lid 3 and the crucible body 1 to form a buffer zone 6, the height of which is 30~100 mm. During vacuum high-temperature purification, the carbon nanotubes to be purified are filled into the purification zone 2, and then the crucible lid 3 is covered. During the vacuum high-temperature purification of carbon nanotubes, the impurity gas in the vacuum high-temperature purification process is discharged through the first exhaust hole 4. The first exhaust hole 4 can also reduce the leakage of carbon nanotubes filled inside the crucible body 1. The buffer zone serves as a buffer area when a large amount of impurity gas is discharged, reducing the leakage and overflow of carbon nanotubes caused by airflow disturbance during the vacuuming process and the discharge of impurity gas. On the other hand, the buffer zone can also serve as a buffer area for some of the leaked carbon nanotubes, preventing the carbon nanotubes from directly leaking and spraying into the equipment, thereby causing short circuits or other circuit damage problems.

[0025] Furthermore, the crucible body 1 is made of carbon-carbon composite material, and the crucible lid 3 is also made of carbon-carbon composite material. The carbon-carbon composite crucible body 1 and lid 3 are less prone to cracking under repeated high-temperature thermal shock conditions. Their high-temperature resistance and wear resistance help extend the crucible's service life and reduce maintenance and material costs. Moreover, the carbon-carbon composite material has a very low carbon ash content, resulting in fewer volatile impurities and contaminants compared to graphite. Due to the excellent thermal conductivity of the carbon-carbon composite crucible body 1 and lid 3, heat can be transferred quickly and uniformly during high-temperature purification, helping to ensure temperature stability and consistency in experiments and processes. Under vacuum and high-temperature conditions, impurity gases generated in the carbon nanotubes are smoothly discharged through the first exhaust hole 4 on the lid 3, achieving the purpose of purifying the carbon nanotube powder.

[0026] like Figure 2As shown, this device can also be used in a stacked manner. The crucible body 1 has multiple second exhaust holes 5 on the side wall of the buffer area, which are connected to the buffer area. The diameter of the second exhaust holes 5 is 0.5~5.0 mm, preferably 1.5~3 mm. The bottom of the crucible body 1 is provided with an annular groove 7, which matches the size of the outer wall of the top inlet and outlet of the crucible body 1. When adjacent crucible bodies 1 are stacked, the bottom of the upper crucible body 1 is locked into the top opening of the lower crucible body 1, thereby ensuring the stability of adjacent crucible bodies 1 when stacked.

[0027] In use, the crucible body 1 filled with carbon nanotubes is covered with the crucible lid 3 and then stacked. During the vacuum high-temperature purification process, the impurity gas discharged from the first exhaust port 4 of the lower crucible body 1 first enters the buffer area and then is discharged from the crucible body 1 through the second exhaust port 5.

[0028] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A high-temperature purification crucible for carbon nanotubes, characterized in that: The crucible includes a crucible body (1) and a crucible lid (3). The top opening of the crucible body (1) forms an inlet and outlet for easy insertion and removal of carbon nanotubes. The crucible lid (3) is detachably installed inside the crucible body (1). The crucible lid (3) divides the crucible body (1) into a purification zone (2) on the lower side and a buffer zone (6) on the upper side. The crucible lid (3) is provided with a plurality of first exhaust holes (4), which connect the purification zone (2) and the buffer zone (6).

2. The high-temperature purification crucible for carbon nanotubes according to claim 1, characterized in that: An annular stepped groove is provided on the inner wall of the upper side of the crucible body (1). The diameter of the crucible cover (3) matches the outer diameter of the annular stepped groove. The crucible cover (3) is installed inside the crucible body (1) through the annular stepped groove.

3. The high-temperature purification crucible for carbon nanotubes according to claim 1, characterized in that: The diameter of the first vent (4) is 0.5~5.0 mm.

4. The high-temperature purification crucible for carbon nanotubes according to claim 1, characterized in that: The height of the buffer area (6) is 30 ~ 100 mm.

5. The high-temperature purification crucible for carbon nanotubes according to claim 1, characterized in that: The crucible body (1) is made of carbon-carbon composite material, and the crucible lid (3) is made of carbon-carbon composite material.

6. The high-temperature purification crucible for carbon nanotubes according to any one of claims 1 to 5, characterized in that: The crucible body (1) has a through hole on the side wall of the buffer area (6) to form a second vent hole (5). The bottom of the crucible body (1) is provided with an annular groove (7) that matches the top opening of the crucible body. When stacked, the bottom of the upper crucible body (1) is fitted into the top opening of the lower crucible body (1) through the annular groove (7).

7. The high-temperature purification crucible for carbon nanotubes according to claim 6, characterized in that: The diameter of the second vent (5) is 0.5~5.0 mm.

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