An apparatus for preparing single-walled carbon nanotubes by a floating catalyst method

Abstract

The present invention belongs to the technical field of single-walled carbon nanotube preparation, and particularly relates to a device for preparing single-walled carbon nanotubes by a floating catalyst method, comprising: a reaction mechanism including a reaction furnace tube and a first heating mechanism for heating the reaction furnace tube; a first raw material conveying mechanism including a sublimation tank for storing a catalyst and a second heating mechanism for heating the sublimation tank, the sublimation tank being communicated with the reaction furnace tube through a first conveying path, wherein the catalyst in the sublimation tank is sublimated and forms a gas state by heating the sublimation tank through the second heating mechanism; a second raw material conveying mechanism including an injection pump for storing a liquid carbon source and a gas cylinder for storing a gas, the injection pump and the gas cylinder being communicated with the reaction furnace tube through a second conveying path; and a collection mechanism including a collection assembly communicated with the reaction furnace tube. The device of the present invention can improve the yield of single-walled carbon nanotubes and the stability of the preparation process.

Description

Technical Field

[0001] The present invention belongs to the technical field of single-walled carbon nanotube preparation, and particularly relates to a device for preparing single-walled carbon nanotubes by a floating catalyst method. Background Art

[0002] Single-walled carbon nanotubes are a kind of carbon material with a seamless tubular structure at the nanoscale, having excellent properties such as high strength, light weight, stable performance, softness and flexibility, good thermal conductivity, and large specific surface area. They are the most representative and have the most excellent performance among nanomaterials. There are many methods for preparing single-walled carbon nanotubes, but it is difficult to achieve low-cost mass production, especially the mass production of high-quality single-walled carbon nanotubes is even more difficult to achieve. In the existing processes, the fluidized bed method is difficult to obtain single-walled carbon nanotubes and is commonly used for preparing multi-walled carbon tubes; arc discharge and laser evaporation methods have high energy, the reaction process is difficult to control, and impurity separation is difficult.

[0003] Therefore, it is necessary to design a device for preparing single-walled carbon nanotubes by a floating catalyst method to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a device for preparing single-walled carbon nanotubes by a floating catalyst method to solve the above problems and achieve the purpose of improving the yield of single-walled carbon nanotubes and the stability of the preparation process.

[0005] To achieve the above purpose, the present invention provides the following solution: A device for preparing single-walled carbon nanotubes by a floating catalyst method, comprising:

[0006] A reaction mechanism, including a reaction furnace tube and a first heating mechanism for heating the reaction furnace tube;

[0007] A first raw material conveying mechanism, including a sublimation tank for storing a catalyst and a second heating mechanism for heating the sublimation tank. The sublimation tank is communicated with the reaction furnace tube through a first conveying path. Among them, by heating the sublimation tank through the second heating mechanism, the catalyst in the sublimation tank sublimes and forms a gas state;

[0008] A second raw material conveying mechanism, including an injection pump for storing a liquid carbon source and a gas cylinder for storing a gas. The injection pump and the gas cylinder are communicated with the reaction furnace tube through a second conveying path;

[0009] A collection mechanism, including a collection component communicated with the reaction furnace tube.

[0010] Preferably, the sublimation tank includes a tank body. The top end of the tank body is fixedly communicated with a catalyst source outlet through a sealing flange. The catalyst source outlet is fixedly communicated with the end of the first conveying path. The second heating mechanism includes a heating jacket, and the heating jacket is fixedly sleeved on the outer side wall of the tank body.

[0011] Preferably, a rectifying part is arranged inside the reaction furnace tube. The end of the first conveying passage is located below the rectifying part, and the end of the second conveying passage is located above the rectifying part. The first heating mechanism includes a heating component, and the heating component is fixedly sleeved on the middle part of the outer side wall of the reaction furnace tube.

[0012] Preferably, the rectifying part includes a rectifying device. The rectifying device is fixedly connected to the top of the inner side wall of the reaction furnace tube. The rectifying device includes a columnar main body adapted to the inner diameter of the reaction furnace tube. A plurality of through holes are axially formed through the columnar main body, and the plurality of through holes are equidistantly distributed along the circumferential direction of the columnar main body. The end of the first conveying passage passes through one of the through holes and is located below the through hole, and the end of the second conveying passage is located above the columnar main body.

[0013] Preferably, the outlet end of the injection pump is fixedly communicated with one end of a liquid carbon source passage, and the other end of the liquid carbon source passage is fixedly communicated with the end of the second conveying passage.

[0014] Preferably, the outlet end of the gas cylinder for carrier gas is fixedly communicated with one end of a carrier gas passage, and the other end of the carrier gas passage is fixedly communicated with the middle part of the second conveying passage.

[0015] Preferably, the collection assembly includes a collection water tank. The top end of the collection water tank is hermetically connected to the bottom of the outer side wall of the reaction furnace tube through a rubber ring. The bottom end of the reaction furnace tube extends below the liquid level in the collection water tank. The top of the side wall of the collection water tank is fixedly communicated with an exhaust gas discharge pipe. The height of the exhaust gas discharge pipe is higher than the liquid level height in the collection water tank, and a filter screen is arranged between the exhaust gas discharge pipe and the side wall of the collection water tank.

[0016] Preferably, a catalytic source gas flow controller is arranged on the first conveying passage.

[0017] Preferably, a carrier gas flow controller is arranged on the carrier gas passage.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] In the present invention, the catalytic source is injected in a gaseous state through a sublimation tank, which can be free from the limitation of the solubility of the catalytic source in the carbon source, greatly increase the concentration of catalytic particles, provide more carbon nanotube growth points, and avoid the phenomenon of local precipitation of the catalytic source affected by the heat absorption of the carbon source in the reaction furnace tube, greatly improving the yield of carbon nanotube preparation and the stability of the preparation process. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings:

[0021] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0022] Figure 2 It is a scanning electron microscope photograph of the surface morphology of the carbon nanotube fiber produced by the device of the present invention.

[0023] Among them, 1. reaction furnace tube; 11. heating component; 12. rectifying device; 13. injection flange; 2. first conveying passage; 21. catalytic source gas flow controller; 3. second conveying passage; 31. liquid carbon source passage; 311. injection pump; 32. carrier gas passage; 321. carrier gas flow controller; 322. carrier gas cylinder; 33. quartz injection tube; 4. sublimation tank; 41. tank body; 42. heating jacket; 43. sealing flange; 44. catalytic source outlet; 5. collection component; 51. collection water tank; 52. rubber ring; 53. filter screen; 54. tail gas discharge pipe. Specific embodiments

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0026] Refer to Figure 1 - Figure 2 , the present invention provides a device for preparing single-walled carbon nanotubes by the floating catalyst method, including:

[0027] A reaction mechanism, including a reaction furnace tube 1 and a first heating mechanism for heating the reaction furnace tube 1;

[0028] A first raw material conveying mechanism, including a sublimation tank 4 for storing a catalyst and a second heating mechanism for heating the sublimation tank 4. The sublimation tank 4 is connected to the reaction furnace tube 1 through a first conveying passage 2. Among them, the sublimation tank 4 is heated by the second heating mechanism to sublime the catalyst in the sublimation tank 4 and form a gas state;

[0029] The second raw material conveying mechanism includes an injection pump 311 for storing a liquid carbon source and a gas cylinder 322 for storing a gas. The injection pump 311 and the gas cylinder 322 are connected to the reaction furnace tube 1 through a second conveying path 3;

[0030] The collection mechanism includes a collection assembly 5 connected to the reaction furnace tube 1.

[0031] The reaction furnace tube 1 is used to provide a growth environment for carbon nanotubes. The reaction furnace tube 1 includes a first section, an intermediate section, and a second section connected in sequence; the first conveying path 2 and the second conveying path 3 are hermetically connected to the first section; the first heating mechanism is used to control the process temperature of the intermediate section of the reaction furnace tube 1.

[0032] In a further optimized solution, the sublimation tank 4 includes a tank body 41. The top end of the tank body 41 is fixedly connected through a sealing flange 43 to a catalytic source outlet 44. The catalytic source outlet 44 is fixedly connected to the end of the first conveying path 2. The second heating mechanism includes a heating jacket 42, and the heating jacket 42 is fixedly sleeved on the outer side wall of the tank body 41.

[0033] The tank body 41 is used to store the catalytic source, and the heating jacket 42 is used to control the temperature inside the tank body 41.

[0034] The material of the tank body 41 includes any one or a combination of two of quartz and corundum; the main material of the heating jacket 42 is a heat-conducting material, and the heat-conducting material includes metal and / or graphite, preferably copper; the heating jacket 42 can control the temperature inside the tank body 41 at 100 - 300 °C.

[0035] The sealing flange 43 and the tank body 41 are in a detachable connection manner, and the heating jacket 42 is located below the sealing flange 43.

[0036] In a further optimized solution, a rectifying part is arranged inside the reaction furnace tube 1. The end of the first conveying path 2 is located below the rectifying part, and the end of the second conveying path 3 is located above the rectifying part. The first heating mechanism includes a heating assembly 11, and the heating assembly 11 is fixedly sleeved on the middle part of the outer side wall of the reaction furnace tube 1.

[0037] The heating assembly 11 selects a heat-insulating layer and / or an active heating structure, which can ensure that the temperature inside the reaction furnace tube 1 is maintained above 150 °C.

[0038] The first conveying path 2 penetrates through the rectifying part and then extends into the reaction furnace tube 1, so that when the intermediate section reaches the process temperature, the temperature at the end of the first conveying path 2 is above 500 °C.

[0039] Furthermore, one end of a quartz injection tube 33 is fixedly connected to the end of the second conveying path 3, and the other end of the quartz injection tube 33 passes through an injection flange 13 at the top of the reaction furnace tube 1 and is located above the rectifying part.

[0040] For a further optimized solution, the rectifying section includes a rectifying device 12, which is fixedly connected to the top inner wall of the reaction furnace tube 1. The rectifying device 12 includes a columnar main body adapted to the inner diameter of the reaction furnace tube 1. A number of through holes are axially formed through the columnar main body, and the number of through holes are equally spaced along the circumferential direction of the columnar main body. The end of the first conveying passage 2 passes through one of the through holes and is located below the through hole, and the end of the second conveying passage 3 is located above the columnar main body.

[0041] For a further optimized solution, the outlet end of the injection pump 311 is fixedly communicated with one end of the liquid carbon source passage 31, and the other end of the liquid carbon source passage 31 is fixedly communicated with the end of the second conveying passage 3.

[0042] For a further optimized solution, the outlet end of the gas cylinder 322 is fixedly communicated with one end of the carrier gas passage 32, and the other end of the carrier gas passage 32 is fixedly communicated with the middle part of the second conveying passage 3.

[0043] For a further optimized solution, the collection assembly 5 includes a collection water tank 51. The top end of the collection water tank 51 is hermetically connected to the bottom outer wall of the reaction furnace tube 1 through a rubber ring 52. The bottom end of the reaction furnace tube 1 extends into the liquid level in the collection water tank 51. The top of the side wall of the collection water tank 51 is fixedly communicated with an exhaust gas discharge pipe 54. The height of the exhaust gas discharge pipe 54 is higher than the liquid level height in the collection water tank 51. A filter screen 53 is arranged between the exhaust gas discharge pipe 54 and the side wall of the collection water tank 51.

[0044] The collection water tank 51 is connected to the second section of the reaction furnace tube 1 for collecting the carbon nanotube precursor output from the second section of the reaction furnace tube 1.

[0045] For a further optimized solution, a catalytic source gas flow controller 21 is arranged on the first conveying passage 2.

[0046] The catalytic source gas flow controller 21 is used to control the flow rate of the catalytic source gas.

[0047] For a further optimized solution, a carrier gas flow controller 321 is arranged on the carrier gas passage 32.

[0048] The tail end of the carrier gas passage 32 is connected to the upper end of the quartz injection tube 33, which is used to drive the liquid carbon source to continue to flow downward. The carrier gas passage 32 is composed of the convergence of the argon and hydrogen gas passages. The argon and hydrogen gas passages are respectively provided with a carrier gas flow controller 321 for pumping the required flow rate of the process gas into the reaction furnace tube 1.

[0049] The present invention adopts the method of separately injecting the catalytic source and the carbon source. The catalytic source is directly sublimated into gas and then introduced into the reaction zone, while the liquid carbon source enters the reaction zone under the drive of the carrier gas.

[0050] In the present invention, the injection positions of the catalytic source and the carbon source are staggered, with the injection position of the carbon source being above and that of the catalytic source being below. After the carbon source fully volatilizes, expands, and absorbs heat, it then passes through the injection position of the catalytic source, bringing the sublimated gas of the catalytic source into the reaction zone for reaction together.

[0051] The present invention is provided with a rectifying device. Above the rectifying device is the outlet of the liquid carbon source, and below it is the outlet of the catalytic source. The unstable gas flow formed by the full expansion of the liquid carbon source and the carrier gas forms a uniform downward gas flow after passing through the rectifying device, and then drives the catalytic source gas into the reaction zone together.

[0052] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, 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 thus should not be construed as a limitation to the present invention.

[0053] The embodiments described above are only for describing the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solution of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An apparatus for preparing single-walled carbon nanotubes by a floating catalyst method, characterized in that, Comprising: A reaction mechanism, including a reaction furnace tube (1) and a first heating mechanism for heating the reaction furnace tube (1); A first raw material conveying mechanism, including a sublimation tank (4) for storing a catalyst and a second heating mechanism for heating the sublimation tank (4), the sublimation tank (4) being communicated with the reaction furnace tube (1) through a first conveying path (2), wherein the catalyst in the sublimation tank (4) is sublimated and forms a gas state by heating the sublimation tank (4) through the second heating mechanism; A second raw material conveying mechanism, including an injection pump (311) for storing a liquid carbon source and a gas cylinder (322) for storing a gas, the injection pump (311) and the gas cylinder (322) being communicated with the reaction furnace tube (1) through a second conveying path (3); A collection mechanism, including a collection assembly (5) communicated with the reaction furnace tube (1); A rectifying part is arranged inside the reaction furnace tube (1), the end of the first conveying path (2) is located below the rectifying part, the end of the second conveying path (3) is located above the rectifying part, and the first heating mechanism includes a heating assembly (11), and the heating assembly (11) is fixedly sleeved on the middle part of the outer side wall of the reaction furnace tube (1); The rectifying part includes a rectifying device (12), the rectifying device (12) is fixedly connected to the top of the inner side wall of the reaction furnace tube (1), the rectifying device (12) includes a columnar main body adapted to the inner diameter of the reaction furnace tube (1), a plurality of through holes are axially formed through the columnar main body, and the plurality of through holes are equally spaced along the circumferential direction of the columnar main body. The end of the first conveying path (2) passes through one of the through holes and is located below the through hole, and the end of the second conveying path (3) is located above the columnar main body; The sublimation tank (4) includes a tank body (41), the top end of the tank body (41) is fixedly communicated with a catalyst source outlet (44) through a sealing flange (43), the catalyst source outlet (44) is fixedly communicated with the end of the first conveying path (2), and the second heating mechanism includes a heating sleeve (42), and the heating sleeve (42) is fixedly sleeved on the outer side wall of the tank body (41).

2. The apparatus for preparing single-walled carbon nanotubes by floating catalyst method according to claim 1, characterized in that, The outlet end of the injection pump (311) is fixedly communicated with one end of a liquid carbon source path (31), and the other end of the liquid carbon source path (31) is fixedly communicated with the end of the second conveying path (3).

3. The apparatus for preparing single-walled carbon nanotubes by a floating catalyst method according to claim 1, characterized in that, The outlet end of the gas cylinder (322) is fixedly communicated with one end of a carrier gas path (32), and the other end of the carrier gas path (32) is fixedly communicated with the middle part of the second conveying path (3).

4. The device for preparing single-walled carbon nanotubes by a floating catalyst method according to claim 1, characterized in that, The collection component (5) includes a collection water tank (51). The top of the collection water tank (51) is hermetically connected to the bottom of the outer wall of the reaction furnace tube (1) through a rubber ring (52). The bottom end of the reaction furnace tube (1) extends below the liquid level in the collection water tank (51). The top of the side wall of the collection water tank (51) is fixedly communicated with an exhaust gas discharge pipe (54). The height of the exhaust gas discharge pipe (54) is higher than the liquid level height in the collection water tank (51). A filter screen (53) is arranged between the exhaust gas discharge pipe (54) and the side wall of the collection water tank (51).

5. The device for preparing single-walled carbon nanotubes by a floating catalyst method according to claim 1, characterized in that, A catalytic source gas flow controller (21) is arranged on the first conveying path (2).

6. The device for preparing single-walled carbon nanotubes by floating catalyst method according to claim 3, characterized in that, A carrier gas flow controller (321) is arranged on the carrier gas path (32).

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