Micro-negative-pressure single-walled carbon nanotube collecting device and method

Abstract

The invention relates to a micro-negative-pressure single-walled carbon nanotube collecting device and method.The micro-negative-pressure single-walled carbon nanotube collecting device comprises a lower shell, a furnace body is arranged in the lower shell, a gas supply mechanism used for injecting nitrogen into the furnace body is arranged on one side of the lower shell, and a heating mechanism used for preventing deposition of single-walled carbon nanotubes is arranged below the gas supply mechanism; a heat preservation mechanism used for maintaining temperature uniformity in the furnace body is arranged above the lower shell. The pump body is firstly started, then the control valve in a closed state is opened, the synthesized single-walled carbon nanotubes can be conveniently conveyed into the cyclone collector, the inner diameter of the air inlet pipe is half of the inner diameter of the discharging pipe, so that the interior of the furnace body is in a micro-negative pressure state, local turbulence or dead angles are avoided through directional airflow control, and the production efficiency of the single-walled carbon nanotubes is improved. The method is characterized in that by-products are rapidly extracted from a reaction zone, deposition on the surfaces of the products is reduced, and meanwhile, micro-negative pressure uniformly sucks air flow, so that a carbon source and a catalyst are in full contact, and directional and uniform growth of the single-walled carbon nanotubes is promoted.

Description

Technical Field

[0001] This invention relates to the field of single-walled carbon nanotube synthesis technology, specifically to a micro-negative pressure single-walled carbon nanotube collection device and method. Background Technology

[0002] Single-walled carbon nanotubes (SUVs) are one-dimensional nanomaterials formed by rolling up a single layer of graphene. They possess unique electronic structures, excellent mechanical properties, and broad application potential. Currently, commonly used industrial methods for synthesizing SUVs mainly include traditional floating catalysis, plasma catalytic cracking, and vacuum arc pyrolysis.

[0003] Traditional floating catalytic cracking uses transition metals as catalysts to synthesize carbon nanotubes through the cracking of carbon-containing gases under atmospheric or low-pressure conditions. This method is simple and low-cost, but the products often contain a significant amount of amorphous carbon and metallic impurities, and furnace blockage is a common problem during collection. Plasma catalytic cracking uses high-temperature plasma to excite the decomposition of carbon source gases, producing high-purity carbon nanotubes. However, it has high equipment costs and energy consumption, and the reaction system is typically designed for atmospheric or positive pressure, making it easy for byproducts to adhere to the product surface, affecting purity and consistency. Vacuum arc cracking is usually carried out under inert gas protection, effectively controlling the reaction atmosphere. However, due to high equipment sealing requirements, byproducts easily deposit on the inner wall of the reaction chamber under atmospheric or positive pressure operation, and there is a risk of gas leakage during collection, posing a safety hazard. The above methods mostly use atmospheric or positive pressure for collection. While negative pressure collection is beneficial for product extraction, it is prone to introducing air due to valve leaks, inadequate furnace sealing, etc., leading to catalyst oxidation and deactivation, product structural defects, and even safety accidents.

[0004] Therefore, there is an urgent need for a single-walled carbon nanotube collection device and method that can both utilize negative pressure to promote product export and reduce impurity adhesion, and ensure system sealing and safety to prevent air intrusion. Summary of the Invention

[0005] The technical problem solved by this solution is: How to solve the problem that since the synthesis of single-walled carbon nanotubes needs to be carried out at high temperatures, if the furnace is under positive or normal pressure, byproducts such as amorphous carbon and graphite particles may diffuse with the airflow and adhere to the surface of carbon nanotubes, leading to a decrease in product purity; How to solve the problem that heat from the outer wall of the furnace can easily be transferred to the outside, making it difficult to effectively maintain the uniformity of the temperature inside the furnace, and that outside air may seep in through the gaps in the furnace body, leading to catalyst oxidation and deactivation or defects in the carbon nanotube structure.

[0006] The objective of this invention can be achieved through the following technical solution: a micro-negative pressure single-walled carbon nanotube collection device, comprising a lower shell, a furnace body being disposed inside the lower shell, and support legs being fixedly installed at the four corners of the bottom of the lower shell; a gas supply mechanism for injecting nitrogen into the furnace body is disposed on one side of the lower shell; a heating mechanism for preventing the deposition of single-walled carbon nanotubes is disposed below the gas supply mechanism; and a heat preservation mechanism for maintaining the temperature uniformity inside the furnace body is disposed above the lower shell. The heating mechanism includes a first support plate, which is fixedly connected to the middle of two support legs, and a pump body is fixedly installed on the top of the first support plate. The output end of the pump body is connected to an air blowing pipe.

[0007] A further technical improvement of the present invention is that: a cyclone collector is provided below the first support plate, the cyclone collector is existing technology, the input end of the pump body is connected to an air extraction pipe, the input end of the air extraction pipe passes through the first support plate and is connected to the output end of the cyclone collector.

[0008] A further technical improvement of the present invention is that: an L-shaped heat-insulating pipe is fixedly inserted into the bottom of the lower shell, and a feeding pipe is provided inside the L-shaped heat-insulating pipe. The input end of the feeding pipe is connected to the feeding port at the bottom of the furnace body, and the output end of the feeding pipe is connected to the input end of the cyclone collector.

[0009] A further technical improvement of the present invention is as follows: one end of the L-shaped heat-insulating tube is in contact with the outer wall of the cyclone collector, and an exhaust hole is opened on the side wall of the L-shaped heat-insulating tube away from the cyclone collector. The output end of the blowing pipe passes through the first support plate and is connected to the end of the L-shaped heat-insulating tube near the cyclone collector. In the process of synthesizing single-walled carbon nanotubes, the pump body is turned on first, and then the control valve in the closed state is opened to facilitate the transport of the synthesized single-walled carbon nanotubes into the cyclone collector. Since the inner diameter of the air inlet pipe is half the inner diameter of the feed pipe, the furnace body is in a state of slight negative pressure. Through directional airflow control, local turbulence or dead zones are avoided, and by-products are quickly extracted from the reaction zone, reducing the deposition on the product surface. At the same time, the slight negative pressure, through uniform airflow, allows the carbon source and catalyst to fully contact each other, promoting the directional and uniform growth of single-walled carbon nanotubes.

[0010] A further technical improvement of the present invention is that: the gas supply mechanism includes a second support plate fixedly connected to the side wall of the lower shell, and a gas storage tank is provided on the top of the second support plate. The gas storage tank is filled with sufficient nitrogen gas, and the output end of the gas storage tank is connected to an air inlet pipe.

[0011] A further technical improvement of the present invention is that: the output end of the air inlet pipe is fixedly inserted through the lower shell and communicates with the top of the furnace body; a control valve is fixedly installed at the end of the air inlet pipe near the gas storage tank; and the inner diameter of the air inlet pipe is half the inner diameter of the feed pipe.

[0012] A further technical improvement of the present invention is that: the heat preservation mechanism includes an upper shell, the port of the upper shell corresponds in size to the port of the lower shell, and a sealing ring is provided at the port of the upper shell, and a first heat preservation layer is fixedly embedded in the inner wall of the upper shell.

[0013] A further technical improvement of the present invention is as follows: A driving cylinder is longitudinally arranged above the upper shell, the extended end of the driving cylinder is fixedly connected to the top of the upper shell, and the mounting end of the driving cylinder is fixedly connected to the external mounting structure; by controlling the extended end of the driving cylinder to extend to its maximum length, the upper shell is lowered to close with the lower shell, and with the cooperation of the sealing ring, the sealing of the upper shell and the lower shell is ensured. The upper shell and the lower shell with the sealing ring prevent the air containing oxygen and moisture from the outside from seeping in through the gaps in the furnace body, which would cause the catalyst to oxidize and deactivate or the single-wall carbon nanotube structure to become defective. The surface of the furnace body is insulated by the first insulation layer and the second insulation layer, which can effectively reduce the heat transfer to the outside, reduce energy consumption and maintain the temperature uniformity inside the furnace.

[0014] A collection method for a micro-negative pressure single-walled carbon nanotube collection device, the collection method specifically includes the following steps: Step 1: Before synthesizing single-walled carbon nanotubes, the extended end of the drive cylinder is extended to its maximum length, causing the upper shell to descend and close with the lower shell. With the help of a sealing ring, the airtightness of the upper and lower shells is ensured. The sealing ring between the upper and lower shells prevents air containing oxygen and moisture from seeping in through the gaps in the furnace body, which could lead to catalyst oxidation and deactivation or defects in the single-walled carbon nanotube structure. The surface of the furnace body is insulated by the first and second insulation layers, which can effectively reduce heat transfer to the outside, reduce energy consumption, and maintain the uniformity of temperature inside the furnace. Step 2: During the synthesis of single-walled carbon nanotubes, first turn on the pump, then open the control valve which was in the closed state to facilitate the delivery of the synthesized single-walled carbon nanotubes into the cyclone collector. Since the inner diameter of the air inlet pipe is half the inner diameter of the feed pipe, the furnace is in a state of slight negative pressure. Through directional airflow control, local turbulence or dead zones are avoided, and by-products are quickly extracted from the reaction zone, reducing the deposition on the product surface. At the same time, the slight negative pressure, through uniform airflow, ensures that the carbon source and catalyst are in full contact, promoting the directional and uniform growth of single-walled carbon nanotubes. Step 3: During the collection of single-walled carbon nanotubes, the single-walled carbon nanotubes are transported to the cyclone collector through the feeding pipe. Then, the high-temperature airflow is drawn out by the pump and injected into the L-shaped heat-insulating pipe through the air blowing pipe, and then discharged from the exhaust hole. In this process, the high-temperature airflow provides insulation to the outer wall of the feeding pipe, preventing the temperature inside the feeding pipe from dropping. This prevents the single-walled carbon nanotubes from condensing and depositing on the inner wall of the feeding pipe due to temperature drop, which could lead to blockage. At the same time, heat-insulating the feeding pipe can also reduce the probability of amorphous carbon, graphite fragments and other byproducts adhering to the feeding pipe, thereby reducing the difficulty of subsequent cleaning.

[0015] The main innovative points of this invention include: Micro-negative pressure collection technology: By controlling the frequency and airflow of the exhaust fan, a micro-negative pressure environment of 1000Pa to 8000Pa is maintained inside the furnace. This not only facilitates the smooth escape of single-walled carbon nanotubes from the furnace, preventing blockage, but also significantly reduces the content of amorphous carbon and metallic impurities in the product, thereby improving product purity. Too low a negative pressure results in low product formation efficiency, while too high a pressure can easily cause airflow turbulence and pipe blockage. Double-layer shell sealing structure: The double-layer shell structure with upper and lower shells and sealing rings effectively isolates the outside air, prevents oxygen and moisture from seeping into the furnace, avoids catalyst oxidation and product structure defects, and improves the safety and operational stability of the system, solving the safety hazards of easy leakage in traditional negative pressure collection devices. Integrated design of heat preservation and airflow circulation: By combining L-shaped heat preservation pipe with cyclone collector, the high-temperature airflow drawn out by the pump body is used to heat the outer wall of the feed pipe, preventing the condensation and deposition of single-wall carbon nanotubes during transportation, while reducing the adhesion of by-products in the pipe, thus achieving a dual improvement in heat energy recycling and collection efficiency.

[0016] Compared with the prior art, the beneficial effects of the present invention are: In the process of synthesizing single-walled carbon nanotubes, the pump is turned on first, and then the control valve, which was in a closed state, is opened to facilitate the transport of the synthesized single-walled carbon nanotubes into the cyclone collector. Since the inner diameter of the air inlet pipe is half the inner diameter of the feed pipe, the furnace is in a state of slight negative pressure. Through directional airflow control, local turbulence or dead zones are avoided, and by-products are quickly extracted from the reaction zone, reducing the deposition on the product surface. At the same time, the slight negative pressure, through uniform airflow, ensures that the carbon source and catalyst are in full contact, promoting the directional and uniform growth of single-walled carbon nanotubes.

[0017] In use, this invention controls the extension end of the drive cylinder to extend to its maximum length, causing the upper shell to descend and close with the lower shell. Combined with a sealing ring, this ensures the airtightness of the upper and lower shells. The sealing ring on the upper and lower shells prevents external air containing oxygen and moisture from seeping in through gaps in the furnace body, which could lead to catalyst oxidation and deactivation or defects in the single-walled carbon nanotube structure. The first and second insulation layers insulate the surface of the furnace body, effectively reducing heat transfer to the outside, lowering energy consumption, and maintaining temperature uniformity within the furnace. Attached Figure Description

[0018] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 This is a three-dimensional schematic diagram of the heating mechanism structure of the present invention; Figure 3 This is a three-dimensional schematic diagram of the internal structure of the L-shaped heat-insulating pipe of the present invention; Figure 4 This is a three-dimensional schematic diagram of the gas supply mechanism structure of the present invention; Figure 5 This is a three-dimensional schematic diagram of the thermal insulation mechanism of the present invention.

[0020] In the diagram: 1. Gas supply mechanism; 2. Heating mechanism; 3. Support leg; 4. Lower shell; 5. Second insulation layer; 6. Furnace body; 7. Insulation mechanism; 101. Gas storage tank; 102. Second support plate; 103. Air inlet pipe; 104. Control valve; 201. Pump body; 202. Air extraction pipe; 203. First support plate; 204. Cyclone collector; 205. L-shaped insulation pipe; 206. Air blowing pipe; 207. Material discharge pipe; 208. Exhaust port; 701. Drive cylinder; 702. Upper shell; 703. First insulation layer; 704. Sealing ring. Detailed Implementation

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

[0022] Please see Figures 1-5As shown, a micro-negative pressure single-walled carbon nanotube collecting device includes a lower shell 4, a furnace body 6 is arranged inside the lower shell 4, and support legs 3 are fixedly installed at the four corners of the bottom of the lower shell 4. A gas supply mechanism 1 for injecting nitrogen into the furnace body 6 is arranged on one side of the lower shell 4. A heating mechanism 2 for preventing the deposition of single-walled carbon nanotubes is arranged below the gas supply mechanism 1. A heat preservation mechanism 7 for maintaining the temperature uniformity inside the furnace body 6 is arranged above the lower shell 4.

[0023] Please see Figure 1 and Figure 2 As shown, the heating mechanism 2 includes a first support plate 203, which is fixedly connected to the middle of two support legs 3, and a pump body 201 is fixedly installed on the top of the first support plate 203. The output end of the pump body 201 is connected to an air blowing pipe 206.

[0024] Please see Figure 2 As shown, a cyclone collector 204 is provided below the first support plate 203. The cyclone collector 204 is existing technology. The input end of the pump body 201 is connected to the suction pipe 202. The input end of the suction pipe 202 passes through the first support plate 203 and is connected to the output end of the cyclone collector 204.

[0025] Please see Figure 2 and Figure 3 As shown, an L-shaped insulation pipe 205 is fixedly inserted into the bottom of the lower shell 4. A feeding pipe 207 is provided inside the L-shaped insulation pipe 205. The input end of the feeding pipe 207 is connected to the feeding port at the bottom of the furnace body 6, and the output end of the feeding pipe 207 is connected to the input end of the cyclone collector 204.

[0026] Please see Figure 2 and Figure 3 As shown, one end of the L-shaped heat-insulating tube 205 is in contact with the outer wall of the cyclone collector 204, and an exhaust hole 208 is opened on the side wall of the L-shaped heat-insulating tube 205 away from the cyclone collector 204. The output end of the blowing pipe 206 passes through the first support plate 203 and is connected to the end of the L-shaped heat-insulating tube 205 near the cyclone collector 204. In the process of synthesizing single-walled carbon nanotubes, the pump body 201 is turned on first, and then the control valve 104, which is in a closed state, is turned on to facilitate the transport of the synthesized single-walled carbon nanotubes into the cyclone collector 204. Since the inner diameter of the air inlet pipe 103 is half the inner diameter of the feed pipe 207, the furnace body 6 is in a state of slight negative pressure. Through directional airflow control, local turbulence or dead corners are avoided, and by-products are quickly extracted from the reaction zone, reducing the deposition on the product surface. At the same time, the slight negative pressure, through uniform airflow, allows the carbon source and catalyst to fully contact each other, promoting the directional and uniform growth of single-walled carbon nanotubes.

[0027] Please see Figure 1 and Figure 4 As shown, the gas supply mechanism 1 includes a second support plate 102 fixedly connected to the side wall of the lower shell 4. A gas storage tank 101 is provided on the top of the second support plate 102. The gas storage tank 101 is filled with sufficient nitrogen gas, and the output end of the gas storage tank 101 is connected to an air inlet pipe 103.

[0028] Please see Figure 1 and Figure 4 As shown, the output end of the air inlet pipe 103 is fixedly inserted through the lower shell 4 and connected to the top of the furnace body 6. A control valve 104 is fixedly installed at the end of the air inlet pipe 103 near the gas storage tank 101, and the inner diameter of the air inlet pipe 103 is half the inner diameter of the feed pipe 207.

[0029] Please see Figure 1 and Figure 5 As shown, the above-mentioned heat preservation mechanism 7 includes an upper shell 702, the port of the upper shell 702 corresponds in size to the port of the lower shell 4, and a sealing ring 704 is provided at the port of the upper shell 702. A first heat preservation layer 703 is fixedly embedded in the inner wall of the upper shell 702.

[0030] Please see Figure 1 and Figure 5 As shown, a driving cylinder 701 is longitudinally arranged above the upper shell 702. The extended end of the driving cylinder 701 is fixedly connected to the top of the upper shell 702, and the mounting end of the driving cylinder 701 is fixedly connected to the external mounting structure. By controlling the extended end of the driving cylinder 701 to extend to its maximum length, the upper shell 702 is lowered to close with the lower shell 4. With the cooperation of the sealing ring 704, the sealing of the upper shell 702 and the lower shell 4 is ensured. The upper shell 702 and the lower shell 4, together with the sealing ring 704, prevent the air containing oxygen and moisture from seeping in through the gaps in the furnace body 6, which would cause catalyst oxidation and deactivation or defects in the single-wall carbon nanotube structure. The surface of the furnace body 6 is insulated by the first insulation layer 703 and the second insulation layer 5, which can effectively reduce the heat transfer to the outside, reduce energy consumption, and maintain the temperature uniformity inside the furnace body 6.

[0031] Please see Figure 1 As shown, a second insulation layer 5 is fixedly embedded on the inner wall of the lower shell 4.

[0032] Example 1: Micro-negative pressure control experiment The pump body 201 frequency was set to 30Hz, and the control valve 104 opening was set to 50%, stabilizing the negative pressure inside the furnace body 6 at approximately 4000Pa. Under these conditions, a single-walled carbon nanotube synthesis experiment was conducted, with the reaction lasting for 2 hours. The results showed that the product collection rate increased by approximately 25% compared to atmospheric pressure collection, there was no clogging in the furnace, the amorphous carbon content in the product decreased to below 5%, and the metallic impurity content was below 1%, indicating that the micro-negative pressure environment significantly promoted product extraction and reduced impurity adhesion.

[0033] Example 2: Verification of Negative Pressure Safety and Sealing The device was operated under a negative pressure of 8000Pa. Gas leaks were detected at the junction of the upper shell 702 and lower shell 4, as well as at the connection points of the air inlet pipe 103 and the feed pipe 207, using a gas leak detector. After 12 hours of continuous operation, the oxygen content inside the furnace body 6 remained below 10ppm, indicating that the double-shell structure combined with the sealing ring 704 effectively isolates air, ensuring the safe and stable operation of the system.

[0034] Example 3: Comparison Experiment with Different Negative Pressure Values Comparative experiments were conducted with furnace negative pressures set at 1000 Pa, 4000 Pa, and 8000 Pa, respectively, each lasting one hour. The results showed: Under 1000Pa conditions, the product collection efficiency is low, and there is slight carbon buildup at the furnace outlet; Under 4000Pa conditions, the product is collected uniformly, without carbon buildup, and has the lowest impurity content; The collection efficiency is highest under 8000Pa conditions, but a small amount of deposits appear on the inner wall of the feed pipe 207.

[0035] Overall, the optimal operating range for a slight negative pressure is around 4000 Pa.

[0036] Example 4: Verification of thermal insulation effect Without activating the pump body 201 for air blowing and heat preservation, the outlet temperature of the feed pipe 207 dropped from 600℃ to 200℃ within 10 minutes, resulting in the condensation and deposition of a large amount of carbon nanotubes. After activating the air blowing pipe 206 to introduce a high-temperature airflow into the L-shaped heat preservation pipe 205, the outer wall temperature of the feed pipe 207 stabilized above 550℃, there was no deposition or blockage during the conveying process, and the by-product adhesion rate decreased by approximately 60%.

[0037] A collection method for a micro-negative pressure single-walled carbon nanotube collection device, the collection method specifically includes the following steps: Step 1: Before synthesizing single-walled carbon nanotubes, the extended end of the drive cylinder 701 is extended to its maximum length, causing the upper shell 702 to descend and close with the lower shell 4. With the cooperation of the sealing ring 704, the sealing of the upper shell 702 and the lower shell 4 is ensured. The upper shell 702 and the lower shell 4, together with the sealing ring 704, prevent the air containing oxygen and moisture from seeping in through the gaps in the furnace body 6, which could lead to catalyst oxidation and deactivation or defects in the single-walled carbon nanotube structure. The surface of the furnace body 6 is insulated by the first insulation layer 703 and the second insulation layer 5, which can effectively reduce the heat transfer to the outside, reduce energy consumption, and maintain the temperature uniformity inside the furnace body 6. Step 2: In the process of synthesizing single-walled carbon nanotubes, first turn on the pump 201, then open the control valve 104 which is in the closed state, so that the nitrogen in the gas storage tank 101 is injected into the furnace 6. After heating, the single-walled carbon nanotubes are carried along the feed pipe 207 into the cyclone collector 204. Since the inner diameter of the air inlet pipe 103 is half the inner diameter of the feed pipe 207, the furnace 6 is in a state of slight negative pressure. Through directional airflow control, local turbulence or dead zones are avoided, and by-products are quickly extracted from the reaction zone, reducing the deposition on the product surface. At the same time, the slight negative pressure, through uniform airflow, allows the carbon source and catalyst to fully contact each other, promoting the directional and uniform growth of single-walled carbon nanotubes. Step 3: During the collection of single-walled carbon nanotubes, the single-walled carbon nanotubes are transported to the cyclone collector 204 through the feed pipe 207. Then, the high-temperature airflow is extracted by the pump body 201 and injected into the L-shaped heat-insulating pipe 205 along the air blowing pipe 206, and then discharged from the exhaust port 208. During this process, the high-temperature airflow provides heat insulation to the outer wall of the feed pipe 207, preventing the temperature inside the feed pipe 207 from dropping. This prevents the single-walled carbon nanotubes from condensing and depositing on the inner wall of the feed pipe 207 due to temperature drop, which could lead to blockage. At the same time, heat insulation of the feed pipe 207 can also reduce the probability of amorphous carbon, graphite fragments and other byproducts adhering to the feed pipe 207, thereby reducing the difficulty of subsequent cleaning.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A micro-negative pressure single-walled carbon nanotube collecting device comprising a lower shell (4), characterized in that: The inside of the lower shell (4) is provided with a furnace body (6), and the bottom four corners of the lower shell (4) are fixedly provided with supporting legs (3), one side of the lower shell (4) is provided with a gas supply mechanism (1) for injecting nitrogen into the furnace body (6), the lower side of the gas supply mechanism (1) is provided with a heating mechanism (2) for preventing single-walled carbon nanotube deposition, and the upper side of the lower shell (4) is provided with a heat preservation mechanism (7) for maintaining the uniformity of the temperature in the furnace body (6). The heating mechanism (2) comprises a first supporting plate (203), the first supporting plate (203) is fixedly connected with the middle part of two supporting legs (3), and the top of the first supporting plate (203) is fixedly provided with a pump body (201), and the output end of the pump body (201) is communicated with a blowing pipe (206).

2. The micro-negative pressure single-walled carbon nanotube collection device according to claim 1, wherein The lower side of the first supporting plate (203) is provided with a cyclone collector (204), the input end of the pump body (201) is communicated with an air suction pipe (202), and the input end of the air suction pipe (202) penetrates through the first supporting plate (203) and is communicated with the output end of the cyclone collector (204).

3. The micro-negative pressure single-walled carbon nanotube collection device according to claim 2, wherein The bottom of the lower shell (4) is provided with an L-shaped heat preservation pipe (205), the inside of the L-shaped heat preservation pipe (205) is provided with a downcomer (207), the input end of the downcomer (207) is communicated with the downcomer of the bottom of the furnace body (6), and the output end of the downcomer (207) is communicated with the input end of the cyclone collector (204).

4. The micro-negative pressure single-walled carbon nanotube collection device according to claim 3, wherein One end of the L-shaped heat preservation pipe (205) is in contact with the outer wall of the cyclone collector (204), and the side wall of the end of the L-shaped heat preservation pipe (205) away from the cyclone collector (204) is provided with an exhaust hole (208), and the output end of the blowing pipe (206) is communicated with the end of the L-shaped heat preservation pipe (205) close to the cyclone collector (204).

5. The micro-negative pressure single-walled carbon nanotube collection device of claim 1, wherein, The gas supply mechanism (1) comprises a second supporting plate (102) fixedly connected with the side wall of the lower shell (4), and the top of the second supporting plate (102) is provided with a gas storage tank (101), and the output end of the gas storage tank (101) is communicated with an air inlet pipe (103).

6. The micro-negative pressure single-walled carbon nanotube collection device according to claim 5, wherein The output end of the air inlet pipe (103) is fixedly penetrated through the lower shell (4) and communicated with the top of the furnace body (6), a control valve (104) is fixedly installed on the end of the air inlet pipe (103) close to the gas storage tank (101), and the inner diameter of the air inlet pipe (103) is half of the inner diameter of the downcomer (207).

7. The micro-negative pressure single-walled carbon nanotube collection device of claim 1, wherein, The heat preservation mechanism (7) comprises an upper shell (702), the port of the upper shell (702) corresponds in size to the port of the lower shell (4), and the port of the upper shell (702) is provided with a sealing ring (704), and the inner wall of the upper shell (702) is fixedly embedded with a first heat preservation layer (703).

8. The micro-negative pressure single-walled carbon nanotube collection device according to claim 7, wherein The upper side of the upper shell (702) is longitudinally provided with a driving cylinder (701), and the extending end of the driving cylinder (701) is fixedly connected with the top of the upper shell (702).

9. The method of claim 1-8, wherein the micro-negative pressure single-walled carbon nanotube collection device is used. The collection method specifically comprises the following steps: Step one: before synthesizing single-walled carbon nanotubes, by controlling the extension of the driving cylinder (701) to the longest, so that the upper shell (702) is lowered to the lower shell (4) is closed, and then cooperate with the sealing ring (704), to ensure the sealing of the upper shell (702) and the lower shell (4), the surface of the furnace body (6) is insulated by the first insulation layer (703) and the second insulation layer (5); Step two: in the process of synthesizing single-walled carbon nanotubes, first open the pump body (201), and then open the control valve (104) in the closed state, so as to facilitate the delivery of synthesized single-walled carbon nanotubes to the cyclone collector (204). Because the inner diameter of the inlet pipe (103) is half the size of the inner diameter of the downcomer (207), the furnace body (6) is in a micro-negative pressure state, which reduces the deposition on the surface of the product. At the same time, the micro-negative pressure can make the carbon source and the catalyst fully contact by uniformly sucking the gas flow; Step three: in the process of collecting single-walled carbon nanotubes, the single-walled carbon nanotubes are delivered to the cyclone collector (204) through the downcomer (207), and then the high-temperature gas flow is pumped out through the pump body (201), so that the high-temperature gas flow is injected into the L-shaped insulation pipe (205) along the blowing pipe (206), and then discharged from the exhaust hole (208). In this process, the high-temperature gas flow provides insulation for the outer wall of the downcomer (207), preventing the single-walled carbon nanotubes from condensing and depositing on the inner wall of the downcomer (207) due to temperature drop. At the same time, by insulating the downcomer (207), the probability of amorphous carbon and graphite fragments adhering to the downcomer (207) is also reduced.

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