A carbon nanotube preparation device

Abstract

This invention discloses a carbon nanotube preparation apparatus, belonging to the field of carbon nanotube preparation technology. It is used for the preheating and gasification of a catalyst and its delivery to a reactor. The apparatus includes a preheating cylinder containing a crucible for holding a solid catalyst and a heating assembly for heating the crucible. An inlet pipe and an outlet pipe are fixedly connected to the preheating cylinder. The inlet pipe introduces an inert carrier gas into the preheating cylinder, and the outlet pipe delivers the mixture of the gasified catalyst and the carrier gas to the reactor. The preparation apparatus provided in this invention continuously heats the crucible using the heating assembly, enabling the catalyst inside the crucible to vaporize. Simultaneously, the flowing carrier gas delivers the vaporized catalyst to the reactor, providing a continuous and stable gaseous catalyst source, thereby ensuring the continuity of the carbon nanotube synthesis process and improving the quality of the carbon nanotube product.

Description

Technical Field

[0001] This invention relates to the field of carbon nanotube preparation technology, and specifically discloses a carbon nanotube preparation apparatus. Background Technology

[0002] Carbon nanotubes, also known as buckytubes, are one-dimensional quantum materials with a unique structure. The main methods for preparing carbon nanotubes include arc discharge, laser evaporation, and chemical vapor deposition (CVD). CVD is one of the most widely used methods, offering advantages such as control over the nanotube structure and diameter, high product purity, and suitability for large-scale production. This method generates carbon nanotubes by decomposing carbon-containing gases (such as methane) under the action of a catalyst. Floating catalyst chemical vapor deposition (FCCVD) is a special variant of chemical vapor deposition (CVD). In this process, the catalyst is introduced into the reaction chamber in a gaseous or vaporized form. Unlike traditional CVD methods that use solid or liquid catalysts, FCCVD relies on a floating catalyst suspended in the gas phase during deposition. This technique is particularly suitable for synthesizing high-quality nanomaterials such as carbon nanotubes (CNTs) or graphene, and allows for precise control over their structure and properties.

[0003] For example, patent CN218200074U, published on January 3, 2023, discloses a quantitative conveying device for carbon nanotube catalysts, including: a quantitative mechanism and a conveying mechanism. The quantitative mechanism includes a hopper, which has interconnected inner chambers. The bottom opening of the inner chambers is movably connected to a hopper door via an opening and closing component. Weighing components are symmetrically arranged on both sides of the outer wall of the hopper. The weighing components include a support rod with an open top groove. A pressure sensor is slidably connected in the groove. A connecting rod is detachably connected above the pressure sensor. The connecting rod is slidably connected in the groove, and the top of the connecting rod extends out of the groove and is fixedly connected to a support plate. The support plate is fixedly connected to the outer wall of the hopper. The conveying mechanism includes a conveying cylinder located below and connected to the hopper. The bottom end of the support rod is fixedly connected to the conveying cylinder. A push plate is slidably connected in the conveying cylinder. This device can improve the quantitative accuracy of the catalyst raw materials, reduce errors, reduce dust diffusion, and improve production efficiency.

[0004] For example, patent CN119527896B, published on May 6, 2025, discloses a raw material conveying device for carbon nanotube material preparation, belonging to the field of carbon nanotube preparation technology. It mainly includes a conveying device with at least two sets of support legs; a preheating box fixedly installed on the support legs; a support plate fixedly installed on one side of the preheating box; an inlet on one side of the preheating box; an outlet on the other side of the preheating box; and a heating wire fixedly installed at the top inside the preheating box. This raw material conveying device for carbon nanotube material preparation, by setting up a preheating box and a preheating tube assembly inside the preheating box, can heat the catalyst when conveying it from the raw material storage area to the fluidized bed equipment. Furthermore, the main body of the preheating tube assembly is coiled, thereby increasing the catalyst conveying time and allowing the catalyst to remain in the preheating box for a longer period, thus achieving the effect of preheating the catalyst.

[0005] When catalysts are added to the reactor using existing catalyst delivery devices, it is not possible to ensure that the catalysts are in a gasified state, which fails to meet the preparation requirements of floating catalyst chemical vapor deposition and easily leads to an increase in by-products and a decrease in yield and quality. Summary of the Invention

[0006] The purpose of this invention is to provide a carbon nanotube preparation apparatus.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A carbon nanotube preparation apparatus for preheating and gasifying a catalyst and conveying it to a reactor includes a preheating cylinder, a crucible for holding a solid catalyst and a heating assembly for heating the crucible inside the preheating cylinder, an inlet pipe and an outlet pipe fixed to the preheating cylinder, the inlet pipe for introducing inert carrier gas into the preheating cylinder, and the outlet pipe for conveying the mixture of the gasified catalyst and the carrier gas to the reactor.

[0009] The above-mentioned preparation apparatus includes a preheating cylinder comprising a vertically placed cylinder body, both ends of which are fixedly connected to end caps, and an air inlet pipe and an air outlet pipe are both fixedly connected to the end caps located at the top of the cylinder body.

[0010] The above-mentioned preparation apparatus includes an inductor coil as the heating component. The middle part of the inductor coil is spiral-shaped and fitted outside the crucible. Both ends of the inductor coil protrude from the side of the cylinder. The crucible is made of graphite.

[0011] The aforementioned preparation apparatus further includes a feeding chamber installed on a preheating cylinder. The feeding chamber has an upper opening and a lower opening, with the lower opening located directly above the crucible. The feeding chamber is equipped with a sealing assembly that closes the upper opening and / or the lower opening. The side wall of the feeding chamber is also equipped with a vacuum suction port.

[0012] The above-mentioned preparation device includes a sealing assembly comprising a first sealing block and a second sealing block, which are fixedly connected by a connecting rod. The feeding bin is cylindrical, and the first and second sealing blocks are driven to move along the axial direction of the feeding bin.

[0013] In the above-mentioned preparation device, a feeding groove is provided on the first sealing block, and a discharge hole is provided in the middle of the first sealing block. A guide pipe is fixedly connected to the lower surface of the first sealing block at the position corresponding to the discharge hole. A blocking component is also provided on the first sealing block, and the blocking component is driven to block the discharge hole.

[0014] In the above-mentioned preparation device, a first sleeve is fixedly connected to the upper inner wall of the feeding chamber, and a second sleeve is fixedly connected to the upper surface of the first sealing block. When the upper opening of the feeding chamber is in the open state, the lower end of the first sleeve extends into the inner side of the second sleeve.

[0015] In the above-mentioned preparation device, the upper opening of the feeding chamber is a flared mouth, the cross-section of the second sealing block is an inverted frustum, and the second sealing block is adapted to the inner wall of the upper opening of the feeding chamber. A sealing gasket is provided on the side wall of the second sealing block.

[0016] The above-mentioned preparation device includes a baffle that is slidably mounted on a first sealing block. The baffle slides radially along the discharge hole. A threaded rod is rotatably mounted inside the first sealing block at a position corresponding to the baffle. The threaded rod and the baffle are threadedly connected. A rotating shaft is rotatably mounted inside the connecting rod. The lower end of the rotating shaft is connected to the threaded rod in a transmission manner.

[0017] In the above-mentioned preparation device, a locking element is provided on the first sealing block. The locking element has a locking state that can lock the baffle in the sealing position. When the inside of the feeding chamber is at normal pressure, the locking element is in the locked state. When the inside of the feeding chamber is evacuated, the locking element releases the lock on the baffle.

[0018] In the above technical solution, the preparation apparatus provided in the embodiments of the present invention continuously heats the crucible through a heating component so that the catalyst inside the crucible can be heated and vaporized. At the same time, the flowing carrier gas can transport the vaporized catalyst to the reactor and provide a continuous and stable gaseous catalyst source, thereby ensuring the continuity of the carbon nanotube synthesis process and improving the quality of the carbon nanotube product. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a schematic diagram of the structure provided for an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal structure of the preheating cylinder provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the internal structure of the replenishment bin provided in an embodiment of the present invention;

[0023] Figure 4 A cross-sectional view of the feeding bin and the first sealing block in a mating state provided in an embodiment of the present invention;

[0024] Figure 5 A cross-sectional view of the replenishment bin provided in an embodiment of the present invention;

[0025] Figure 6 A partial cross-sectional view of the first sealing block provided in an embodiment of the present invention;

[0026] Figure 7 Provided for embodiments of the present invention Figure 6 Enlarged view of point A in the middle;

[0027] Figure 8 Provided for embodiments of the present invention Figure 6 Enlarged diagram of point B in the middle.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Preheating cylinder; 11. Cylinder body; 111. Flange pipe; 12. First end cap; 121. Inlet pipe; 122. Outlet pipe; 13. Second end cap; 14. Fixing rod; 15. Fixing plate; 151. Electric push rod; 2. Crucible; 3. Inductor coil; 4. Feeding bin; 41. Top opening; 42. Bottom opening; 43. Vacuum suction port; 44. First sleeve; 5. Sealing assembly; 51. First sealing block; 511. Feeding trough; 512. Discharge port 513. Hole; 514. Guide tube; 515. Second sleeve; 516. Guide groove; 517. Air hole; 52. Second sealing block; 53. Connecting rod; 6. Blocking component; 61. Baffle; 62. Threaded rod; 63. Rotating shaft; 631. First shaft; 632. Second shaft; 633. First end face tooth; 634. Second end face tooth; 635. Second spring; 64. Drive motor; 7. Locking component; 71. Stop block; 72. Airbag; 73. First spring. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," and "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] like Figures 1 to 8 As shown in the figure, an embodiment of the present invention provides a carbon nanotube preparation apparatus for preheating and gasifying a catalyst and conveying it to a reactor. The apparatus includes a preheating cylinder 1, a crucible 2 for holding a solid catalyst and a heating assembly for heating the crucible 2 are provided inside the preheating cylinder 1, and an inlet pipe 121 and an outlet pipe 122 are fixedly connected to the preheating cylinder 1. The inlet pipe 121 is used to introduce an inert carrier gas into the preheating cylinder 1, and the outlet pipe 122 is used to convey the mixture of the gasified catalyst and the carrier gas to the reactor.

[0033] Specifically, this device is used for the preheating and gasification of the catalyst during the preparation of carbon nanotubes, and for conveying the gasified catalyst to the reactor. Its main structure is a preheating cylinder 1, such as... Figures 1 to 3As shown, the preheating cylinder 1 is a vertically placed cylinder, closed at both ends, giving it a cylindrical cavity (hereinafter referred to as the main cavity for ease of description). A crucible 2 is placed within the main cavity, used to hold a solid catalyst such as ferrocene. Furthermore, a heating assembly is also installed in the main cavity to heat the crucible 2, causing the catalyst inside to vaporize. Using a heating assembly to heat the crucible 2 is existing technology and can be directly applied without further explanation. An inlet pipe 121 and an outlet pipe 122 are also fixedly connected to the preheating cylinder 1. The end of the inlet pipe 121 furthest from the preheating cylinder 1 is connected to a carrier gas tank (not shown in the figure), which is filled with an inert gas such as high-purity argon. The end of the outlet pipe 122 furthest from the preheating cylinder 1 is connected to the reactor, facilitating the discharging of the gas. The catalyst and carrier gas mixture is transported to the reactor to ensure the normal progress of the reaction. Obviously, to ensure that the preheating cylinder 1 can be in a vacuum environment during production to avoid air affecting the reaction, the preparation device also includes a vacuum pump, which is connected to the main cavity to facilitate evacuation of the main cavity. An infrared temperature sensor is also installed in the preheating cylinder 1 to detect the temperature inside the preheating cylinder 1. Obviously, to facilitate the control of the opening and closing of the heating component, the introduction of the carrier gas, and the operation of the vacuum pump based on the measurement results of the infrared temperature sensor, the preparation device also includes a PLC controller. The infrared temperature sensor, the heating component, and the vacuum pump are all connected to the controller. Using the controller to control the opening and closing of the heating component and the vacuum pump is existing technology and can be directly applied without further explanation.

[0034] During the production process, the main cavity of the preheating cylinder 1 is first evacuated, and the heating component is started to preheat the crucible 2 to remove the air and trace amounts of water molecules from the main cavity. Then, carrier gas is introduced into the preheating cylinder 1 until the gas pressure inside the preheating cylinder 1 is at atmospheric pressure. Then, the solid catalyst is placed in the crucible 2, and the heating component continues to heat the crucible 2. The catalyst is heated and vaporized, and the mixture of the vaporized catalyst and the carrier gas is transported to the reactor through the gas outlet pipe 122.

[0035] The preparation apparatus provided in this embodiment of the invention continuously heats the crucible 2 through a heating component, enabling the catalyst inside the crucible 2 to be heated and vaporized. Simultaneously, the flowing carrier gas transports the vaporized catalyst to the reactor, providing a continuous and stable gaseous catalyst source, thereby ensuring the continuity of the carbon nanotube synthesis process and improving the quality of the carbon nanotube product.

[0036] Furthermore, the preheating cylinder 1 includes a vertically placed cylinder 11, with end caps fixed to both ends of the cylinder 11, and the air inlet pipe 121 and the air outlet pipe 122 are both fixed to the end caps located on the upper part of the cylinder 11.

[0037] Specifically, such as Figures 1 to 3As shown, the preheating cylinder 1 includes a cylinder body 11 and two sets of parallel end caps. The two end caps are used to seal the upper and lower openings of the cylinder body 11, respectively. For ease of description, the end cap 12 seals the upper opening of the cylinder body 11, while the end cap 13 seals the lower opening. Both the first end cap 12 and the second end cap 13 are made of stainless steel, while the cylinder body 11 is made of quartz. The diameters of both the first end cap 12 and the second end cap 13 are larger than the outer diameter of the cylinder body 11. The edges of the first end cap 12 and the second end cap 13 are connected as a single unit by a fixing rod 14 and a nut. A heat insulation pad, which can be made of ceramic, is provided in the middle of the second end cap 13 to reduce the heat absorbed by the second end cap 13. Furthermore, an air inlet pipe 121 and an air outlet pipe 122 are both fixed to the first end cap 12. The air inlet pipe 121 is fixed to... Figure 1 On the left side of the first end cap 12 in the view, the vent pipe 122 is fixed to... Figure 1 On the right side of the first end cap 12 in the view, it is set up in such a way that, since the outlet pipe 122 is connected to the top of the main cavity, during the catalyst gasification process, the trace amounts of liquid catalyst droplets or solid particles that are not completely gasified will sink down and fall back into the high-temperature crucible 2 under the action of gravity due to their high density and continue to be heated and gasified; while the inlet pipe 121 is connected to the top of the main cavity, which can prevent the low-temperature carrier gas from directly impacting the high-temperature crucible 2 at the bottom of the main cavity and the hot steam that has just been gasified, but instead it will flow from top to bottom and gradually preheat.

[0038] Furthermore, the heating component includes an inductor coil 3, the middle of which is spiral-shaped and fitted onto the outside of the crucible 2, and both ends of the inductor coil 3 protrude from the side of the cylinder 11. The crucible 2 is made of graphite.

[0039] Specifically, the heating component uses medium-frequency induction heating, which includes an inductor coil 3. The inductor coil 3 is a copper tube, and its middle part is spiral-shaped and fitted onto the outside of the crucible 2. The inductor coil 3 does not contact the outer wall of the crucible 2, and both ends of the inductor coil 3 protrude from the side of the cylinder 11. Figure 2 As shown, the inductor coil 3 extends from the right side of the cylinder 11. A flange tube 111 is fixed to the cylinder 11 at the position corresponding to the inductor coil 3. Both ends of the inductor coil 3 extend outward from the flange tube 111. The heating assembly also includes a medium-frequency power supply and a water cooling system, which are existing technologies and can be directly applied without further description. In this embodiment, the crucible 2 is heated by medium-frequency induction heating, which has the advantages of high heating efficiency, fast speed and high precision, and is conducive to temperature control during catalyst gasification. Graphite is an excellent non-metallic conductor, and its resistivity is very suitable for electromagnetic induction heating. In addition, graphite itself has good high temperature resistance and thermal stability. The graphite crucible 2 is very suitable for heating and gasifying solid catalysts.

[0040] In another embodiment of the present invention, a feeding bin 4 is also included, which is installed on the preheating cylinder 1. The feeding bin 4 has an upper opening 41 and a lower opening 42. The lower opening 42 is located directly above the crucible 2. A sealing assembly 5 is provided on the feeding bin 4 to close the upper opening 41 and / or the lower opening 42. A vacuum suction port 43 is also provided on the side wall of the feeding bin 4.

[0041] Specifically, since the preparation of carbon nanotubes is usually continuous, and in the above embodiments, it is not convenient to periodically replenish the solid catalyst to the preheating cylinder 1 under the premise of completely isolating it from the outside air; in this embodiment, the preparation device also includes a feeding chamber 4 installed on the preheating cylinder 1. The feeding chamber 4 is cylindrical and vertically fixed to the middle of the first end cap 12. The feeding chamber 4 has an upper opening 41 and a lower opening 42, wherein the lower opening 42 is directly opposite to and above the crucible 2 in the main cavity; in addition, a sealing assembly 5 is provided on the feeding chamber 4. The sealing assembly 5 is used to seal one of the upper opening 41 and the lower opening 42 or to seal both of them simultaneously. In this embodiment, the sealing assembly 5 includes electrically controlled sealing valves provided at both the upper opening 41 and the lower opening 42, and a vacuum suction port 43 is provided on the side wall of the feeding chamber 4. The vacuum suction port 43 is connected to a vacuum pump through a pipe.

[0042] When it is necessary to replenish solid catalyst into crucible 2, adjust the sealing component 5 to seal the lower opening 42 while keeping the upper opening 41 open. Add solid catalyst into the feed chamber 4 through the upper opening 41. Then, adjust the sealing component 5 to seal both the upper opening 41 and the lower opening 42 simultaneously, and evacuate the feed chamber 4 using a vacuum pump. Finally, adjust the state of the sealing component 5 to first seal the upper opening 41 to prevent outside air from entering the feed chamber 4, and then open the lower opening 42 to allow the catalyst to fall into crucible 2. Obviously, to prevent the catalyst from being blown away, the flow of carrier gas must be interrupted so that the gas flow in the main chamber stops.

[0043] Furthermore, the sealing assembly 5 includes a first sealing block 51 and a second sealing block 52, which are fixedly connected by a connecting rod 53. The feeding bin 4 is cylindrical, and the first sealing block 51 and the second sealing block 52 are driven to move along the axial direction of the feeding bin 4.

[0044] Specifically, the sealing assembly 5 includes a first sealing block 51 and a second sealing block 52, which are connected as a whole by a connecting rod 53. Figure 2 and Figure 3In the middle, two sets of connecting rods 53 are provided, and are symmetrically arranged about the central axis of the first sealing block 51 and the second sealing block 52. The inner cavity of the feeding bin 4 is cylindrical. The first sealing block 51 is located directly below the second sealing block 52. A linear drive mechanism, such as an electric push rod 151, is also provided above the feeding bin 4. Figure 1 and Figure 3 As shown, a fixing plate 15 is arranged parallel above the first end cap 12. The fixing rod 14 extends upward and is fixedly connected to the fixing plate 15, thus supporting the fixing plate 15. The electric push rod 151 is fixedly connected to the lower surface of the fixing plate 15, and its output end is fixedly connected to the second sealing block 52. The electric push rod 151 drives the second sealing block 52 to move axially along the feeding bin 4. It should be noted that in this embodiment, both the first sealing block 51 and the second sealing block 52 are disc-shaped, and the diameters of both the first sealing block 51 and the second sealing block 52 are equal to the inner diameter of the feeding bin 4. Both the first sealing block 51 and the second sealing block 52 are dynamically sealed to the inner wall of the feeding bin 4.

[0045] In this embodiment, the first sealing block 51 and the second sealing block 52 have a first position, a second position, and a third position during their axial movement along the feed bin 4:

[0046] When in the first position, the first sealing block 51 is higher than the lower opening 42 of the feeding bin 4, and the lower opening 42 is in a closed state. The second sealing block 52 is above the upper opening 41 of the feeding bin 4, and the upper opening 41 is in an open state.

[0047] When in the second position, the first sealing block 51 closes the lower opening 42, and similarly, the second sealing block 52 closes the upper opening 41. At this time, the first sealing block 51, the second sealing block 52, and the feeding bin 4 together form a cylindrical sealed cavity.

[0048] When in the third position, the first sealing block 51 is lower than the lower opening 42 of the feeding chamber 4. At this time, the lower opening 42 is open, while the second sealing block 52 closes the upper opening 41. The solid catalyst in the feeding chamber 4 falls into the crucible 2 through the lower opening 42.

[0049] In this embodiment, the first sealing block 51 and the second sealing block 52 are both dynamically sealed to the feeding bin 4. The first sealing block 51 and the second sealing block 52 are driven synchronously by a single set of drive mechanisms, which can ensure that the upper opening 41 or the lower opening 42 of the feeding bin 4 is in a closed state, or both the upper opening 41 and the lower opening 42 are in a closed state, thereby preventing outside air from entering the main cavity.

[0050] In another embodiment of the present invention, a feeding groove 511 is provided on the first sealing block 51, and a discharge hole 512 is provided in the middle of the first sealing block 51. A guide pipe 513 is fixedly connected to the lower surface of the first sealing block 51 at the position corresponding to the discharge hole 512. A blocking member 6 is also provided on the first sealing block 51, and the blocking member 6 is driven to block the discharge hole 512.

[0051] Specifically, in the above embodiment, by adjusting the height of the first sealing block 51 so that it is lower than the lower opening 42 of the feeding chamber 4, the solid catalyst in the feeding chamber 4 can be added to the crucible 2. This results in the catalyst falling downwards from all sides of the first sealing block 51, and since there is a certain distance between the lower opening 42 of the feeding chamber 4 and the crucible 2, the catalyst cannot fall entirely into the crucible 2. In this embodiment, a feeding groove 511 is provided on the first sealing block 51, and a discharge hole 512 is provided in the middle of the first sealing block 51. A guide pipe 513 is also fixed to the lower surface of the first sealing block 51, and the lower end of the guide pipe 513 penetrates the first end cap 12. Figure 4 and Figure 6 As shown, the feeding trough 511 is funnel-shaped, and the bottom of the feeding trough 511 is connected to the upper end of the discharge hole 512, while the lower end of the discharge hole 512 is connected to the upper end of the guide pipe 513, and the lower end of the guide pipe 513 extends towards the location of the crucible 2; in addition, the first sealing block 51 is provided with a blocking member 6 for blocking the discharge hole 512. Optionally, the blocking member 6 is an existing electric control valve.

[0052] Unlike the above embodiments, in this embodiment, the first sealing block 51 always keeps the lower opening 42 of the feeding chamber 4 closed. The catalyst in the feeding chamber 4 is not added to the crucible 2 through the lower opening 42 of the feeding chamber 4, but is guided by the feeding trough 511 to the discharge hole 512 and added to the crucible 2 through the guide pipe 513. In this embodiment, when the first sealing block 51 moves down synchronously with the second sealing block 52, it is only used to drive the guide pipe 513 to move down synchronously and extend into the crucible 2 to ensure... To ensure that all the catalyst falls into the crucible 2, after the catalyst is added, the shielding part 6 must first block the discharge hole 512, and then drive the second sealing block 52 to move upward along the feeding chamber 4. On the one hand, this will reopen the upper opening 41 of the feeding chamber 4 to prepare for the next catalyst replenishment. On the other hand, the first sealing block 51 can drive the guide pipe 513 to move upward to avoid the guide pipe 513 affecting the gasification of the catalyst in the crucible 2, and also keep the guide pipe 513 away from the high temperature area on the crucible 2.

[0053] Furthermore, a first sleeve 44 is fixedly connected to the upper inner wall of the feeding bin 4, and a second sleeve 514 is fixedly connected to the upper surface of the first sealing block 51. When the upper opening 41 of the feeding bin 4 is in the open state, the lower end of the first sleeve 44 extends into the inner side of the second sleeve 514.

[0054] Specifically, in the above embodiments, the solid catalyst added to the feed hopper 4 is prone to getting stuck between the first sealing block 51 and the inner wall of the feed hopper 4, damaging the dynamic seal of both the first sealing block 51 and the feed hopper 4, and causing obstruction when the first sealing block 51 moves axially along the feed hopper 4; in this embodiment, a first sleeve 44 is fixedly connected to the upper inner wall of the feed hopper 4, and the outer diameter of the upper part of the first sleeve 44 is equal to the inner diameter of the feed hopper 4, so as to facilitate its fixed connection to the inner wall of the feed hopper 4. A second sleeve 514 is fixedly connected to the first sealing block 51, such as... Figure 4 As shown, the second sleeve 514 is fixed to the upper surface of the first sealing block 51, and the outer diameter of the second sleeve 514 is equal to the diameter of the first sealing block 51. The outer diameter of the lower part of the first sleeve 44 is less than or equal to the inner diameter of the second sleeve 514. When the upper opening 41 of the feeding chamber 4 is open, the lower end of the first sleeve 44 extends into the inside of the second sleeve 514. The height of the catalyst replenished each time is lower than the upper opening 41 of the second sleeve 514. This is to prevent catalyst particles from reaching the contact point between the first sealing block 51 and the feeding chamber 4, thereby preventing damage to the dynamic seal between the two.

[0055] Furthermore, the upper opening 41 of the replenishment bin 4 is a flared mouth, the cross section of the second sealing block 52 is an inverted frustum shape, and the second sealing block 52 is adapted to the inner wall of the upper opening 41 of the replenishment bin 4, and a sealing gasket is provided on the side wall of the second sealing block 52.

[0056] Specifically, to avoid affecting the seal between the second sealing block 52 and the replenishment bin 4, in this embodiment, the upper opening 41 of the replenishment bin 4 is a flared opening, such as... Figure 3 and Figure 4 As shown, the cross-section of the second sealing block 52 is an inverted frustum shape, and the second sealing block 52 is adapted to the inner wall of the upper opening 41 of the feeding bin 4. A sealing gasket is fitted on the second sealing block 52. When the second sealing block 52 is driven to move down and contact the inner wall of the upper opening 41 of the feeding bin 4, the upper opening 41 of the feeding bin 4 is closed. With this configuration, on the one hand, the upper opening 41, which is shaped like a flared mouth, facilitates the addition of catalyst. On the other hand, the seal between the second sealing block 52 and the feeding bin 4 is changed from a dynamic seal to a static seal. That is, the seal can be achieved by pressing the second sealing block 52 against the inner wall of the upper opening 41 of the feeding bin 4, which improves the stability of the seal.

[0057] In another embodiment of the present invention, the shielding member 6 includes a baffle 61 slidably mounted on the first sealing block 51. The baffle 61 slides radially along the discharge hole 512. A threaded rod 62 is rotatably mounted in the first sealing block 51 at a position corresponding to the baffle 61. The threaded rod 62 and the baffle 61 are threadedly connected. A rotating shaft 63 is rotatably mounted in each connecting rod 53. The lower end of the rotating shaft 63 is connected to the threaded rod 62 in a transmission connection.

[0058] Specifically, in the above embodiment, the shielding component 6 uses an existing electrically controlled valve. However, since the feed pipe 513 is always located within the main cavity, during production, some heat will reach the first sealing block 51 through the feed pipe 513, which will have a certain impact on the electrically controlled valve located within the first sealing block 51. In this embodiment, the shielding component 6 includes a baffle 61 slidably connected to the first sealing block 51. The first sealing block 51 has a guide groove 515 that restricts the baffle 61 to slide only radially along the discharge hole 512. Threaded rods 62 are rotatably installed within the first sealing block 51 at positions corresponding to the baffle 61. One end is threaded to the baffle 61, and because the baffle 61 is guided and limited by the guide groove 515, when the threaded rod 62 is driven to rotate, the baffle 61 can be driven to slide radially along the discharge hole 512; the shielding member 6 also includes a drive motor 64 disposed on the second sealing block 52, and a rotating shaft 63 disposed in the connecting rod 53. The upper end of the rotating shaft 63 is fixedly connected to the output shaft of the drive motor 64, and the lower end of the rotating shaft 63 is drivenly connected to the end of the threaded rod 62 away from the baffle 71, so that the position of the drive motor 64 is away from the first sealing block 51 and is not affected by the temperature on the first sealing block 51; preferably, such as Figure 4 and Figure 6 As shown, two sets of baffles 61 are provided, and the two baffles 61 are symmetrically arranged in the first sealing block 51 in order to reduce their stroke, so that the discharge hole 512 can be adjusted to the fully open state at a faster speed. Obviously, in order to adapt to the synchronous drive of the two baffles 61, two sets of drive motor 64, threaded rod 62, rotating shaft 63 and connecting rod 53 are also provided.

[0059] In another embodiment of the present invention, a locking member 7 is provided on the first sealing block 51. The locking member 7 has a locking state that can lock the baffle 61 in the blocking position. When the inside of the replenishment bin 4 is at normal pressure, the locking member 7 is in the locking state. When the inside of the replenishment bin 4 is evacuated, the locking member 7 releases the locking of the baffle 61.

[0060] Specifically, after the catalyst is added to the feed hopper 4, it is necessary to ensure that the inner cavity of the feed hopper 4 is sealed, and the inner cavity of the feed hopper 4 is evacuated by a vacuum pump. However, in actual operation, regardless of whether the feed hopper 4 is in a vacuum state, the position of the baffle 61 can be adjusted to open the discharge hole 512. In this embodiment, a locking element 7 is provided inside the first sealing block 51. The locking element 7 can block the baffle 61 in the sealing position. This is the locked state of the locking element 7. When the feed hopper 4 is at normal pressure, the locking element 7 always remains in the locked state. When the feed hopper 4 is gradually evacuated, the locking element 7 can switch from the locked state to the unlocked state based on the pressure difference between the inner cavity of the feed hopper 4 and the outside, thereby releasing the lock on the baffle 61. Figure 6 and Figure 8 As shown, the locking component 7 includes a stop 71 slidably installed within the first sealing block 51. An air bladder 72 is disposed within the first sealing block 51. The stop 71 is fixedly connected to the air bladder 72. When the air bladder 72 inflates or deflates, the stop 71 can slide within the first sealing block 51. A first spring 73 is disposed inside the air bladder 72. When the first spring 73 is in its natural state, the stop 71 extends into the guide groove 515, and at this time, the baffle 61 is in the blocking position of the discharge hole 512. Figure 8 As shown, the stop 71 contacts the side of the baffle 61 corresponding to the threaded rod 62 to prevent the baffle 61 from moving towards the side where the threaded rod 62 is located. The airbag 72 is connected to the internal space of the feed chamber 4, so that when the vacuum pump evacuates the inner cavity of the feed chamber 4, it can also extract gas from the airbag 72, thereby forcing the airbag 72 to contract. Preferably, as shown... Figure 6 As shown, the first sealing block 51 has an air hole 516 inside. The air hole 516 extends from the lower end face of the second sleeve 514 to the side wall of the second sleeve 514 and extends to the upper end face of the second sleeve 514. In this way, while realizing the communication between the air bag 72 and the feeding chamber 4, it can also prevent the catalyst from entering the air hole 516 and causing blockage of the air hole 516. Obviously, in order to ensure that the baffle 61 is released from obstruction by the baffle 71 only when the baffle 71 is in a vacuum state in the feeding chamber 4, the baffle 71 releases its obstruction from the baffle 61 when the air bag 72 is contracted to its minimum state, and the air bag 72 only contracts to its shortest state when the air inside it is completely evacuated. Figure 8 As shown, the airbag 72 contracts along the axial direction of the first spring 73. Let the length change of the airbag 72 from an expanded state (its interior is filled with gas) to a contracted state (the shortest length of the airbag 72) be the contraction length. Then the length of the stop block 71 extending into the guide groove 515 is equal to the contraction length of the airbag 72, so as to ensure that the stop block 71 will not block the sliding of the baffle 61 only after the inner cavity of the feeding bin 4 is evacuated.

[0061] In this embodiment, by connecting the airbag 72 to the feeding chamber 4, when the vacuum pump evacuates the inner cavity of the feeding chamber 4, the gas in the airbag 72 is also drawn out, causing the airbag 72 to gradually contract. The contraction of the airbag 72 drives the stop block 71 to move. Figure 8The airbag moves vertically downwards in the view, passively releasing the lock on the baffle 61, thus ensuring that the baffle 61 can only be driven to move when the inner cavity of the replenishment chamber 4 is evacuated. When the inner cavity of the replenishment chamber 4 is under normal air pressure, the airbag 72 will automatically pump air and expand under the push of the first spring 73 to ensure that the stop block 71 can automatically lock the baffle 61. Obviously, since the airbag 72 is pumped and expanded under the push of the first spring 73, when the baffle 61 is not in the blocking position, the airbag 72 will drive the stop block 71 to move to contact the lower surface of the baffle 61. After the baffle 61 switches to the blocking position, it will move further upwards until the baffle 61 is locked.

[0062] Furthermore, the rotating shaft 63 includes a first shaft 631 and a second shaft 632 coaxially arranged. One of the first shaft 631 and the second shaft 632 is a telescopic shaft. The lower end of the first shaft 631 is fixedly connected to a first end face tooth 633, and the upper end of the second shaft 632 is fixedly connected to a second end face tooth 634. The lower end of the second shaft 632 is connected to the end of the threaded rod 62 away from the baffle 61 through a bevel gear set.

[0063] Specifically, in the above embodiments, to ensure that the drive motor 64 can stop in time when the baffle 61 switches to the blocking state, and to avoid damage to the drive motor 64 itself and the threads of both the threaded rod 62 and the baffle 61, a monitoring component such as a distance sensor or a pressure sensor needs to be installed on the baffle 61. The monitoring component feeds back the measurement results to the controller to control the drive motor 64 to stop in time. Similarly, the sensor installed inside the first sealing block 51 is susceptible to high temperature. In this embodiment, the rotating shaft 63 includes a first shaft 631 and a second shaft 632 coaxially arranged. One of the components is a telescopic shaft, the length of which can be changed. It includes an inner shaft and an outer shaft. One end of the outer shaft is fitted onto the outside of the inner shaft. A guide block protrudes from the outer wall of the inner shaft along its length, while a guide groove is formed on the inner wall of the outer shaft along its length. The guide groove cooperates with the guide block to allow the inner and outer shafts to rotate synchronously, and the inner shaft to move axially along the outer shaft. The structure of the telescopic shaft is existing technology and can be directly applied. The cooperation relationship between the guide block and the guide groove is not shown in the diagram. A second spring 635 is fitted onto the outside of the telescopic shaft, maintaining the relative position of the inner and outer shafts. Figure 7 The second shaft 632 is shown as a telescopic shaft, with the second end face tooth 634 fixed to the upper end of the outer shaft, while the lower end of the inner shaft is connected to the threaded rod 62 via a bevel gear set.

[0064] With this configuration, when the baffle 61 is locked, the threaded rod 62 is also locked, meaning it cannot be rotated. The second shaft 632 is connected to the threaded rod 62 via a bevel gear set, so it also cannot be rotated. Similarly, the second end face tooth 634 on the second shaft 632 cannot rotate. Even if the drive motor 64 is started, when it drives the first shaft 631 to rotate, since the first shaft 631 cannot drive the second shaft 632 to rotate, and the second shaft 632 is retractable, the first end face tooth 633 at the lower end of the first shaft 631 will forcefully push the second end face tooth 634 at the upper end of the second shaft 632 away, forcing the second shaft 632 to retract until the first end face tooth 633 disengages from the second end face tooth 634. This maintains the continued rotation of the first end face tooth 633, protecting the drive motor. The drive motor 64 is undamaged. After the baffle 61 is driven to the fully open state, the movement of the baffle 61 is restricted, which locks the threaded rod 62 and the second shaft 632. The second end face tooth 634 also cannot rotate. When the drive motor 64 continues to drive the first shaft 631 to rotate, since the second end face tooth 634 cannot rotate, and the first end face tooth 633 continues to rotate, it will push the second end face tooth 634 away from the first end face tooth 633, causing the second shaft 632 to retract. The elastic force provided by the second spring 635 will assist the second shaft 632 to return to the longest state (in this state, the first end face tooth 633 and the second end face tooth 634 are engaged). This will cause the second end face tooth 634 to drive the second shaft 632 to continuously extend and retract, thereby generating vibration to promote the downward sliding of the catalyst on the first sealing block 51 until the catalyst completely enters the feed tube 513 and falls.

[0065] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A carbon nanotube production apparatus for preheating vaporization of a catalyst and delivery to a reactor, comprising a preheating cylinder, characterized by, The preheating cylinder is provided with a crucible for containing solid catalyst and a heating assembly for heating the crucible, the preheating cylinder is fixedly connected with an inlet pipe and an outlet pipe, the inlet pipe is used for feeding inert carrier gas into the preheating cylinder, and the outlet pipe is used for conveying the mixed gas of the vaporized catalyst and the carrier gas to the reactor; the preheating cylinder is further provided with a feeding bin mounted thereon, the feeding bin has an upper opening and a lower opening, the lower opening is directly above the crucible, the feeding bin is provided with a sealing assembly for sealing the upper opening and / or the lower opening, the sidewall of the feeding bin is further provided with a vacuum suction port, the sealing assembly comprises a first sealing block and a second sealing block, the first sealing block and the second sealing block are fixedly connected by a connecting rod, the feeding bin is in a cylindrical shape, the first sealing block and the second sealing block are driven to move along the axial direction of the feeding bin, the first sealing block is provided with a discharging groove, the middle part of the first sealing block is provided with a discharging hole, the lower surface of the first sealing block is fixedly connected with a guide pipe corresponding to the position of the discharging hole, the first sealing block is further provided with a shielding piece, the shielding piece is driven to block the discharging hole, the shielding piece comprises a baffle slidably mounted on the first sealing block, the baffle slides along the radial direction of the discharging hole, a threaded rod is rotatably mounted in the first sealing block corresponding to the position of the baffle, the threaded rod is threadedly connected with the baffle, a rotating shaft is rotatably mounted in the connecting rod, the lower end of the rotating shaft is in transmission connection with the threaded rod, the first sealing block is provided with a locking piece, the locking piece has a locking state for locking the baffle at the blocking position, when the inside of the feeding bin is at normal pressure, the locking piece is in the locking state, when the inside of the feeding bin is vacuumized, the locking piece releases the locking of the baffle, the locking piece comprises a blocking piece slidably mounted in the first sealing block, the first sealing block is provided with an air bag, the blocking piece is fixedly connected with the air bag, when the air bag is inflated or deflated, the blocking piece can slide in the first sealing block, the inside of the air bag is provided with a first spring, when the first spring is in a natural state, the blocking piece extends into the guide groove, and at this time, the baffle is at the blocking position of the discharging hole, the first sealing block is provided with an air hole, the air hole penetrates through the lower end surface of the second sleeve to the sidewall of the second sleeve and extends to the upper end surface of the second sleeve.

2. The carbon nanotube production apparatus according to claim 1, wherein The preheating cylinder comprises a vertically placed cylinder body, both ends of the cylinder body are fixedly connected with end covers, the inlet pipe and the outlet pipe are fixedly connected to the end cover at the upper part of the cylinder body.

3. The carbon nanotube production apparatus according to claim 2, wherein The heating assembly comprises an inductor, the middle part of the inductor is in a spiral shape and is sleeved outside the crucible, both ends of the inductor penetrate out of the sidewall of the cylinder body, and the crucible is made of graphite.

4. The carbon nanotube production apparatus according to claim 1, wherein The upper inner wall of the feeding bin is fixedly connected with a first sleeve, the upper surface of the first sealing block is fixedly connected with a second sleeve, when the upper opening of the feeding bin is in an open state, the lower end of the first sleeve extends into the inside of the second sleeve.

5. The carbon nanotube production apparatus according to claim 1, wherein The upper opening of the feeding bin is a horn opening, the cross section of the second sealing block is in an inverted circular truncated cone shape, and the second sealing block is matched with the inner wall at the upper opening of the feeding bin, and the sidewall of the second sealing block is provided with a sealing gasket.

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