Device for collecting carbon nanotubes and device for producing carbon nanotubes

Abstract

Provided is a device for collecting carbon nanotubes which comprises: a collection chamber having an opening communicating with a device for yielding carbon nanotubes; and a removal mechanism for removing carbon-nanotube deposits attached to wall surfaces surrounding the opening. The removal mechanism comprises a removal member to be inserted into the deposits and a driving part for moving the removal member between a removal position and a retreat position. The driving part further has a configuration for rotating the removal member on the moving direction of the removal member as a rotation axis.

Description

Carbon nanotube recovery device and carbon nanotube production device

[0001] The present invention relates to a carbon nanotube recovery device and a carbon nanotube production device.

[0002] Carbon nanotubes (hereinafter sometimes referred to as "CNTs") are a new material that has attracted attention in many fields due to their excellent properties such as electrical conductivity, thermal conductivity, and mechanical strength. Patent Document 1 discloses a CNT manufacturing device that uses a chemical vapor deposition (CVD) method to generate CNTs by thermally decomposing a carbon-containing raw material (carbon source).

[0003] Furthermore, Patent Document 2 discloses a CNT manufacturing apparatus equipped with a recovery device for recovering CNTs. In the apparatus described in Patent Document 2, CNT raw materials and a carrier gas are supplied into a reaction tube heated to a high temperature from the upper end thereof, and CNTs are produced as the raw materials pass through the interior of the reaction tube. The produced CNTs are discharged from the lower end of the reaction tube and recovered by a recovery device installed below the reaction tube.

[0004] Japanese Patent Application Publication No. 2019-064918 Japanese Patent Application Publication No. 2023-056489

[0005] Because the CNTs discharged from the reaction tube tend to adhere to solid objects, during the CNT production process, the CNTs adhere to the wall surface near the opening of the recovery chamber that leads to the bottom of the reaction tube. If subsequent CNTs newly produced in the reaction tube further adhere to the CNTs that have adhered to the wall surface, the CNTs will accumulate, and the opening of the recovery chamber may become clogged with the CNT deposits.

[0006] When the opening of the recovery chamber is clogged with CNT deposits, the internal pressure of the reaction tube increases. Even when the internal pressure of the reaction tube increases in this way, cracks usually occur in the CNT deposits due to the increased internal pressure, and the CNTs attached to the wall surface peel off together with the gas discharged from the reaction tube passing through the gaps formed at that time. In other words, even if the opening of the recovery chamber is temporarily clogged with CNT deposits, the CNT discharge state naturally returns to a normal state, so the CNT production process can be continued.

[0007] However, when a large amount of CNT is produced per unit time, or when CNTs that tend to adhere to solid objects are produced, the CNT deposits may not fall off even if the internal pressure of the reaction tube increases, and the opening of the recovery chamber may remain blocked. In such cases, if the internal pressure of the reaction tube increases excessively, the device must be shut down, and the CNT production volume decreases.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a carbon nanotube recovery device and a carbon nanotube production device that prevent clogging of the opening of the recovery chamber that leads to the reaction tube that produces carbon nanotubes.

[0009] The following are examples of aspects of the present invention that solve the above problems: (1) A carbon nanotube recovery device that recovers carbon nanotubes generated by a carbon nanotube generation device, comprising: a recovery chamber having an opening that communicates with the carbon nanotube generation device; and a removal mechanism that removes deposits of carbon nanotubes adhering to wall surfaces around the opening, the removal mechanism having: a removal member that is inserted into the deposits; and a drive unit that moves the removal member between a removal position and a retracted position, the drive unit further having a configuration that rotates the removal member around a rotation axis that is the movement direction of the removal member. (2) The carbon nanotube recovery device according to (1), in which a tip of the removal member is not positioned on the rotation axis. (3) A carbon nanotube recovery device for recovering carbon nanotubes generated by a carbon nanotube generation device, comprising: a recovery chamber having an opening communicating with the carbon nanotube generation device; and a removal mechanism for removing deposits of carbon nanotubes adhering to wall surfaces around the opening, the removal mechanism having: a removal member inserted into the deposits; and a drive unit for moving the removal member between a removal position and a retracted position, the drive unit further having a configuration for moving the removal member in a direction different from the movement direction of the removal member between the removal position and the retracted position. (4) The carbon nanotube recovery device according to any of (1) to (3), wherein the removal member extends parallel to the movement direction. (5) The carbon nanotube recovery device according to any one of (1) to (4), wherein the recovery chamber has a first wall portion having the opening and a second wall portion adjacent to the first wall portion, the retracted position is disposed on the second wall portion side, and a separating member is provided inside the second wall portion to come into contact with the carbon nanotubes adhering to the removing member and separate the carbon nanotubes from the removing member. (6) The carbon nanotube recovery device according to (5), wherein the separating member has a through hole through which the removing member can pass.(7) A carbon nanotube production apparatus comprising: the carbon nanotube production apparatus for producing the carbon nanotubes; and the carbon nanotube recovery apparatus according to any one of (1) to (6). (8) The carbon nanotube production apparatus according to (7), further comprising: a control unit for controlling operation of the removal mechanism, wherein the carbon nanotube production apparatus comprises: a reaction tube to which a raw material gas for the carbon nanotubes is supplied; and a pressure measurement unit for measuring an internal pressure of the reaction tube, wherein the control unit is configured to execute control to move the removal member from the retracted position to the removal position when the internal pressure of the reaction tube measured by the pressure measurement unit exceeds a predetermined pressure value. (9) The carbon nanotube production apparatus according to (7), further comprising: a control unit for controlling operation of the removal mechanism, wherein the control unit is configured to execute control to move the removal member from the retracted position to the removal position when a predetermined time has elapsed since the removal mechanism has completely retracted from the removal position to the retracted position.

[0010] According to the present invention, it is possible to provide a carbon nanotube recovery device and a carbon nanotube production device that prevent clogging of the opening of the recovery chamber that communicates with the reaction tube for producing carbon nanotubes.

[0011] 1 is an explanatory diagram showing a schematic configuration of a CNT manufacturing apparatus according to an embodiment of the present invention; FIG. 2 is an explanatory diagram of the CNT recovery device in FIG. 1 as viewed from below; FIG. 3 is an explanatory diagram of the CNT recovery device in FIG. 1 as viewed from the negative side in the X direction; FIG. 4 is an explanatory diagram of the removal head of the CNT removal mechanism as viewed from the direction of the rotation axis; FIG. 5 is a diagram for explaining a plate that separates CNTs adhering to the removal head; FIG. 6 is a diagram for explaining the operation of the CNT removal mechanism; FIG. 7 is a diagram showing an example of the control flow of the removal mechanism; and FIG. 8 is a diagram showing another example of the control flow of the removal mechanism.

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0013] <Carbon Nanotube Production Apparatus> Figure 1 is an explanatory diagram showing a schematic configuration of a CNT production apparatus 1 for producing carbon nanotubes (hereinafter, sometimes referred to as "CNT") according to this embodiment. In this specification, CNT refers to a tubular carbon allotrope (typically a cylindrical structure with a graphite structure), and includes so-called single-walled CNT, multi-walled CNT, or carbon nanohorns with horn-shaped tube tips. The CNT production apparatus 1 is particularly suitable for use in producing single-walled CNT.

[0014] The CNT manufacturing apparatus 1 has a generation device 10 that generates CNTs and a collection device 20 that collects the CNTs. Note that the "X direction" in the drawing is the depth direction of the collection device 20, the "Y direction" is the width direction of the collection device 20, and the "Z direction" is the vertical direction. These X direction, Y direction, and Z direction are perpendicular to each other.

[0015] (Carbon Nanotube Generator) The CNT generator 10 is an apparatus for generating CNTs using a chemical vapor deposition (CVD) method, in which raw materials such as catalytic metals or catalytic metal compounds are thermally decomposed to generate CNTs. When CNT raw materials are supplied to the generator 10, a carrier gas (e.g., hydrogen gas) is also supplied along with the raw materials. In this specification, the raw materials supplied together with the carrier gas are referred to as raw material gas.

[0016] The generating device 10 includes a reaction tube 11 to which a raw material gas for CNTs is supplied, and a heater 12 arranged around the reaction tube 11 .

[0017] A raw material supply port (not shown) for supplying a raw material gas for CNTs is formed at the upper end of the reaction tube 11. CNTs are produced while the raw material gas supplied from the raw material supply port passes through the heated reaction tube 11, and the produced CNTs are discharged from the lower end of the reaction tube 11.

[0018] The reaction tube 11 is a straight tube, but the shape of the reaction tube 11 is not particularly limited. The cross-sectional shape of the reaction tube 11 perpendicular to the tube axis may be a rounded shape such as a circle, an ellipse, or an egg shape, or a polygonal shape. The material of the reaction tube 11 is selected taking into consideration heat resistance to the heating temperature during CNT production, thermal shock resistance, weather resistance to the atmospheric gas at that temperature, corrosion resistance, and the like. Examples of materials that can be used include alumina (Al2O3), mullite, silicon carbide (SiC), quartz glass, Kanthal (iron-chromium-aluminum alloy), Inconel, and carbon.

[0019] The length of the reaction tube 11 is, for example, 0.5 to 4.0 m, preferably 1.0 to 3.0 m, and more preferably 2.0 to 2.5 m. The inner diameter of the reaction tube 11 is, for example, 10 to 300 mm, preferably 50 to 200 mm, and more preferably 80 to 120 mm.

[0020] The shape and heating method of the heater 12 are not particularly limited as long as they can heat the reaction tube 11 to a temperature suitable for CNT growth. For example, a tungsten heater capable of heating the reaction tube 11 to 500°C to 2000°C, or a carbon heater or silicon carbide heater (SiC heater) capable of heating to 600°C to 1600°C can be used as the heater 12.

[0021] The CNT production apparatus 10 is provided with a pressure gauge 13 as a pressure measurement unit that measures the internal pressure of the reaction tube 11. During the CNT production process, the internal pressure of the reaction tube 11 is monitored by the pressure gauge 13. Information on the pressure measured by the pressure gauge 13 is output to a control unit 50, which will be described later.

[0022] (Carbon nanotube recovery device) Next, a schematic configuration of the CNT recovery device 20 will be described with reference to Figures 2 and 3 in addition to Figure 1. Figure 2 is an explanatory diagram of the recovery device 20 in Figure 1 as seen from below. Figure 3 is an explanatory diagram of the recovery device 20 in Figure 1 as seen from the negative side in the X direction.

[0023] The recovery device 20 is disposed below the production device 10. The recovery device 20 has a recovery chamber 21 that recovers CNTs, and the recovery chamber 21 is formed, for example, in a rectangular parallelepiped shape. An opening 22 that leads to the lower end of the reaction tube 11 of the production device 10 is formed in a ceiling wall portion 21a that serves as a first wall portion of the recovery chamber 21. The CNTs discharged from the lower end of the reaction tube 11 pass through the opening 22 and enter the recovery chamber 21.

[0024] Within the recovery chamber 21, rollers 23 are provided as take-up members for winding up the CNTs that have passed through the opening 22. The rollers 23 are arranged to extend to the negative side in the X direction from a side wall portion 21b, which serves as a second wall portion adjacent to the ceiling wall portion 21a. The rollers 23 are installed so as to be rotatable around the X direction as a rotation axis by a drive mechanism (not shown) installed outside the recovery chamber 21. Furthermore, a total of four rollers 23 are installed at intervals in both the Y and Z directions.

[0025] The above-mentioned multiple rollers 23 each rotate during the CNT production process and wind up the CNTs discharged from the reaction tube 11. The CNTs wound up on any of the rotating rollers 23 become a donut-shaped wound body, and this wound body is recovered from the recovery chamber 21.

[0026] (CNT Removal Mechanism) Next, a description will be given of the CNT removal mechanism 30. The removal mechanism 30 has a function of removing CNT deposits when CNTs adhere to and accumulate on the wall surface around the opening 22.

[0027] The removal mechanism 30 has a removal head 31 as a removal member that is inserted into the CNT deposit, and a drive unit 32 for moving the removal head 31 forward, backward, and rotating it.

[0028] The removal head 31 is a member extending in a direction parallel to the axial direction of the roller 23 (X direction). The tip of the removal head 31 is preferably sharpened so as to easily penetrate the CNT deposits. The installation position of the removal head 31 in the vertical direction (Z direction) is higher than the roller 23 and lower than the opening 22. The specific installation position of the removal head 31 between the roller 23 and the opening 22 may be changed appropriately depending on, for example, the inner diameter of the reaction tube 11. When the amount of CNT discharged per unit time is high, the amount of CNT deposited on the wall surface around the opening 22 also increases. Therefore, even if the removal head 31 is installed at a position distant from the opening 22, the removal head 31 can be brought into contact with the CNT deposits and can remove the CNT deposits. On the other hand, when the amount of CNT emitted per hour is low, CNTs accumulate in an area relatively close to the opening 22, causing the opening 22 to become blocked, so the CNT deposits can be removed by placing the removal head 31 as close to the opening 22 as possible.

[0029] The overall length of the removal head 31 is preferably longer than the diameter of the opening 22. This allows the removal range of CNT deposits adhering to the wall surface around the opening 22 to be expanded, and the effect of preventing the opening 22 from being blocked can be improved.

[0030] The material of the removal head 31 is preferably a material that does not deform when the removal head 31 is used to entangle the CNT deposits and that does not deteriorate due to the heat of the gas discharged from the reaction tube 11, and materials such as molybdenum, tungsten, and steel are selected, for example.

[0031] From the viewpoint of facilitating the removal of CNTs adhering to the surface of the removal head 31 from the removal head 31 after entanglement of the CNT deposits, it is preferable to reduce the surface roughness of the removal head 31. Alternatively, the surface of the removal head 31 may be coated with Teflon (registered trademark).

[0032] The removal head 31 is not limited to being formed from a single needle-shaped member extending linearly, but may be formed from multiple members, such as a bifurcated or trifurcated member.

[0033] The drive unit 32 includes a rotating rod 33 as a rod to which the removal head 31 is attached, a rotary motor 34 as a rotary drive source for rotating the rotating rod 33, and a cylinder 35 as a mechanism for linearly moving the rotating rod 33 in one direction.

[0034] The rotating rod 33 is a member formed, for example, in a columnar or cylindrical shape and extending in the X direction. The removal head 31 is attached to the end of the rotating rod 33 on the collection chamber 21 side, and a rotation motor 34 is connected to the opposite end. The rotating rod 33 rotates around a rotation axis A as a rotation center when driven by the rotation motor 34.

[0035] The removal head 31 extends in a direction parallel to the rotation axis A of the rotating rod 33, but is disposed offset from the rotation axis A. Therefore, the tip 31 a of the removal head 31 is not positioned coaxially with the rotation axis A of the rotating rod 33, and as shown in Figure 4, when the removal head 31 is viewed from the tip 31 a side, the tip 31 a of the removal head 31 is at a position different from the rotation axis A.

[0036] 1, the cylinder 35 is installed outside the side wall portion 21b of the recovery chamber 21 and below the rotating rod 33 so as to be extendable and scalable in the X direction. An end of a cylinder tube 35a of the cylinder 35 is fixed to the side wall portion 21b. The rotating rod 33 and the cylinder rod 35b are arranged parallel to each other, and the end of the rotating rod 33 on the rotation motor 34 side and the end of the cylinder rod 35b are connected by a connecting plate 36 serving as a connecting member.

[0037] According to the configuration of the drive unit 32 described above, the rotating rod 33 moves in the X direction as the cylinder 35 extends and retracts, and the rotating rod 33 rotates around the rotation axis A as driven by the rotation motor 34. Similarly, the removal head 31 attached to the rotating rod 33 also moves in the X direction as the cylinder 35 extends and retracts, and rotates around the rotation axis A.

[0038] The removal head 31 is movable in the X direction, and thus can move between a "removal position" where it removes CNT deposits adhering to the wall surfaces around the opening 22, and a "retraction position" where it does not interfere with the recovery of CNTs passing through the opening 22. The specific positions of the removal position and the retraction position are set appropriately depending on the configuration of the recovery device 20, but the removal position and the retraction position in this embodiment are as follows.

[0039] The removal position is a position where the tip of the removal head 31 is located closer to the side wall 21c than the opening 22, and is exemplified by the position of the removal head 31 shown by the two-dot chain line in Figures 1 and 2. The side wall 21c is a wall that faces the side wall 21b.

[0040] The retracted position is a position where the tip of the removal head 31 is located outside the inner surface of the side wall portion 21b.

[0041] An adapter 37 is provided on the side wall 21b of the recovery chamber 21 as a cylindrical member that accommodates a portion of the rotating rod 33 and the removal head 31. The adapter 37 extends in the X direction, and one end of the adapter 37 is fixed to the side wall 21b. The space inside the adapter 37 is connected to the inside of the recovery chamber 21, and the atmosphere inside the adapter 37 is the same as the atmosphere inside the recovery chamber 21. A sealant 38 is provided on the other end of the adapter 37 to block the outflow of atmosphere from the inside of the adapter 37 to the outside and the inflow of atmosphere from the outside of the adapter 37 to the inside.

[0042] Furthermore, a passage opening 39 through which the removal head 31 and the rotating rod 33 pass is formed in the side wall portion 21b of the recovery chamber 21. A plate 40 is provided on the inner surface of the side wall portion 21b around this passage opening 39 as a separating member that separates the CNTs adhering to the removal head 31 from the removal head 31.

[0043] 5, the plate 40 is formed in a disk shape and is attached to the inner surface of the side wall portion 21b by fastening means such as bolts. A through-hole 41 is formed in the center of the plate 40, through which the removal head 31 and the rotating rod 33 pass when the removal head 31 advances or retreats.

[0044] The through-hole 41 is an opening that is slightly larger than the peripheral shapes of the removal head 31 and the rotating rod 33, and has the same peripheral shape as the peripheral shapes of the removal head 31 and the rotating rod 33. In the present embodiment, the outer shape of the rotating rod 33 is circular, and the initial position of the removal head 31 before rotation is the apex position on the rotation trajectory. Therefore, the shape of the through-hole 41 when viewed from the direction of the rotation axis A is a combination of a circular opening and an opening that extends upward in a substantially linear manner from the apex of the circular opening.

[0045] When the removal head 31 retracts from within the collection chamber 21, this plate 40 comes into contact with the CNTs adhering to the removal head 31. Then, by further retracting the removal head 31 in this state, only the CNTs in contact with the plate 40 remain in the collection chamber 21. Thereafter, the removal head 31 retracts until the tip 31 a of the removal head 31 is positioned outside the collection chamber 21 relative to the plate 40, and the CNTs are separated from the removal head 31.

[0046] The plate 40 is preferably detachably attached to the side wall portion 21b so that it can be replaced with another plate having a different shape of the through-hole 41. This allows a plate having a through-hole 41 that is suitable for the shape of the removal head 31 to be selected and used as appropriate, improving the versatility of the recovery device 20.

[0047] The material of the plate 40 may be, for example, molybdenum, tungsten, steel, etc. In order to make it easier for the CNTs removed from the removal head 31 to fall off the plate 40, the surface of the plate 40 may be coated with Teflon (registered trademark).

[0048] The separating member for separating the CNTs adhering to the removal head 31 is provided as needed, and is not limited to the plate 40 described in this embodiment. The separating member may be any member that can come into contact with the CNTs adhering to the removal head 31 when the removal head 31 is retracted, and separate the CNTs from the removal head 31. Furthermore, the separating member is not limited to being fixed to the inner surface of the side wall portion 21b.

[0049] 6, with the removal mechanism 30 described above, when CNTs adhere to the wall surface around the opening 22 during the CNT production process, forming a substantially hemispherical deposit, the removal head 31 can be advanced from the retracted position to the removal position. This allows the removal head 31 to be inserted into the CNT deposit.

[0050] Furthermore, with the removal mechanism 30, while the removal head 31 is inserted into the CNT deposit, the rotation rod 33 can be rotated to rotate the removal head 31 around the rotation axis A. This allows the removal head 31 to entangle the CNT deposit, and remove the CNTs adhering to the wall surface around the opening 22.

[0051] The CNT recovery device 20 according to this embodiment has been described above. In this recovery device 20, the removal mechanism 30 is provided, which makes it possible to remove CNT deposits that have adhered to the wall surfaces around the openings 22 during the CNT production process. In other words, the occurrence of blockage of the openings 22 by CNT deposits can be suppressed without stopping the CNT production process, thereby improving CNT productivity.

[0052] At least one of the forward, rotation, and backward movements of the removal head 31 may be initiated based on the judgment and operation of an on-site worker, but may also be initiated automatically by an instruction from, for example, the control unit 50 (Figure 1) provided in the CNT manufacturing apparatus 1.

[0053] The control unit 50 is, for example, a computer equipped with a CPU, memory, etc., and has a program storage unit (not shown). The program storage unit stores various programs including, for example, commands for controlling the operation of the removal mechanism 30. For example, the program storage unit stores programs for executing the control described in the following control examples. Note that these programs may be recorded on a computer-readable storage medium and installed into the control unit 50 from the storage medium.

[0054] (Control Example 1) Fig. 7 is a diagram showing an example of a control flow of the removal mechanism 30. In this control example, the internal pressure of the reaction tube 11 during the CNT production process is monitored, and the operation of the removal mechanism 30 is controlled based on the internal pressure. Note that the time measured by the timer in the following description is the time counted within the control unit 50.

[0055] During the CNT production process, as the amount of CNTs deposited on the wall surface around the opening 22 increases, the flow path of the gas discharged from the reaction tube 11 narrows, causing the internal pressure of the reaction tube 11 to rise. If the rising internal pressure of the reaction tube 11 exceeds a predetermined pressure value, the control unit 50 determines that the rise in internal pressure of the reaction tube 11 is abnormal. The "predetermined pressure value" is set appropriately depending on the configuration of the production apparatus 1, the properties of the CNTs to be produced, etc.

[0056] Thereafter, based on a control signal from the control unit 50, the cylinder 35 contracts, and the removal head 31 advances from the retracted position to the removal position. The advancing removal head 31 stops after reaching the removal position. At this stage, the removal head 31 has been inserted into the CNT deposits adhering to the wall surface around the opening 22.

[0057] Next, based on a control signal from the control unit 50, the rotary motor 34 is driven and the removal head 31 starts to rotate. As a result, the CNT deposits are entangled by the removal head 31, and the flow path for the gas discharged from the reaction tube 11 expands. As a result, the internal pressure of the reaction tube 11 decreases.

[0058] The rotation of the removal head 31 may be stopped when the internal pressure of the reaction tube 11 falls to a predetermined pressure value or less. However, at this stage, although the opening 22 is no longer blocked, some CNT deposits may remain on the wall surface around the opening 22. For this reason, it is preferable to continue rotating the removal head 31 in order to further reduce the amount of CNT deposits.

[0059] Therefore, in the control example shown in FIG. 7, after the abnormality in the internal pressure of the reaction tube 11 is resolved, the rotation continuation timer is activated to start measuring time, and the rotation of the removal head 31 is continued until the time of the rotation continuation timer reaches a predetermined time.

[0060] Thereafter, when the time on the rotation continuation timer has elapsed a predetermined time, the removal head 31 starts to stop rotating based on a control signal from the control unit 50. The rotation stopping operation is an operation of rotating the removal head 31 to a position where it can pass through the through-hole 41 of the plate 40 shown in FIG. 5. The "predetermined time" referred to here is set appropriately depending on the configuration of the manufacturing apparatus 1, the properties of the CNTs to be produced, etc.

[0061] After the removal head 31 has rotated to the rotation stop position, the cylinder 35 extends based on a control signal from the control unit 50. This causes the removal head 31 to start retracting, and after the removal head 31 has retracted from the removal position to the retracted position, the extension operation of the cylinder 35 stops, and the retraction of the removal head 31 stops.

[0062] According to this control example, the removal mechanism 30 can be activated only when the opening 22 is clogged with CNT deposits.

[0063] (Control Example 2) Figure 8 is a diagram showing another example of the control flow of the removal mechanism 30. In this control example, the timing of the next operation of the removal mechanism 30 is controlled based on the time elapsed since the previous operation of the removal mechanism 30. Note that the time measured by the timer in the following description is the time counted within the control unit 50.

[0064] In this control example, first, the removal mechanism timer operates during the CNT production process, and the removal mechanism timer measures the elapsed time since the removal mechanism 30 was last operated. Then, when the time on the removal mechanism timer reaches a predetermined time, the cylinder 35 contracts based on a control signal from the control unit 50, and the removal head 31 advances from the retracted position to the removal position. Note that the "predetermined time" referred to here is set appropriately depending on the configuration of the manufacturing apparatus 1, the properties of the CNTs to be produced, and the like.

[0065] After the advancing removal head 31 reaches the removal position and stops, the rotation motor 34 is driven based on a control signal from the control unit 50, and the removal head 31 starts to rotate. At this point, a rotation operation timer is activated, and the time elapsed since the removal head 31 started to rotate is measured.

[0066] Thereafter, when a predetermined time has elapsed on the rotation operation timer, the removal head 31 starts to stop rotating based on a control signal from the control unit 50. Note that the "predetermined time" mentioned here is set appropriately depending on the configuration of the manufacturing apparatus 1, the properties of the CNTs to be produced, and the like.

[0067] After the removal head 31 has rotated to the rotation stop position, the cylinder 35 extends based on a control signal from the control unit 50. This causes the removal head 31 to start retracting, and after the removal head 31 has retracted from the removal position to the retracted position, the extension operation of the cylinder 35 stops, and the retraction of the removal head 31 stops.

[0068] After the removal head 31 stops retracting, the removal mechanism timer is activated to start measuring time, and the removal mechanism 30 enters a standby state until the next timing for activation.

[0069] According to this control example, the removal mechanism 30 can be operated periodically at regular intervals. Therefore, even if the pressure gauge 13 that measures the internal pressure of the reaction tube 11 does not function due to a malfunction, for example, it is possible to prevent the opening 22 from being clogged with CNT deposits.

[0070] (Other Configuration Examples) In the above examples, the movement direction of the removal head 31 when moving forward and backward is the X direction, but the movement direction of the removal head 31 may be a direction different from the extension direction of the roller 23, for example, the Y direction. In other words, the movement direction of the removal head 31 is not particularly limited as long as it can move between the removal position and the retracted position.

[0071] Furthermore, for example, the removal mechanism 30 may include a mechanism for moving the removal head 31, which is located at the CNT removal position, toward the opening 22. With such a removal mechanism 30, for example, it becomes possible to move the removal head 31 closer to the opening 22 after moving the removal head 31 forward, making it easier to remove CNTs deposited on the wall surface around the opening 22. This can enhance the effect of suppressing clogging of the opening 22.

[0072] The shape of the removal head 31 is preferably linear so that the entangled CNTs can easily fall off from the removal head 31, but it may also be non-linear, for example, wavy or spiral. Furthermore, in the above example, the attachment position of the removal head 31 to the rotating rod 33 was offset from the rotation axis A, but if the removal head 31 is non-linear, for example, the attachment positions of the removal head 31 and the rotating rod 33 may be coaxial with the rotation axis A. Even in this case, if the removal head 31 is non-linear, it is possible to entangle the CNT deposits by rotating the removal head 31 around the rotation axis A.

[0073] In the above example, the CNT deposits were entangled by advancing, rotating, and retreating the removal head 31. However, instead of a rotational operation, the removal head 31 may be moved in a direction different from the direction of movement of the removal head 31 between the removal position and the retracted position (for example, two directions perpendicular to the direction of movement of the removal head 31 when advancing or retreating). Specifically, for example, after advancing the removal head 31 to the removal position, the removal head 31 may be moved repeatedly in the order of the positive Z direction, the positive Y direction, the negative Z direction, and the negative Y direction. In this case, the movement trajectory of the tip 31 a of the removal head 31 is rectangular. However, even in this case, the CNT deposits can be entangled in the same way as when the removal head 31 is rotated about the rotation axis A.

[0074] However, if the removal head 31 is not rotated, a mechanism for moving the removal head 31 in three axes is required. Therefore, from the viewpoint of simplifying the device configuration and reducing its size, it is preferable to employ a mechanism for rotating the removal head 31. Note that the mechanism for moving the removal head 31 forward, backward, and backward is not limited to the mechanism using the rotating rod 33, the rotating motor 34, and the cylinder 35 exemplified in the above embodiment.

[0075] In the above example, the axial direction of the reaction tube 11 is vertical, but the axial direction may be horizontal or may be in another direction.

[0076] Although the present invention has been described above by way of example, it is understood that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and that such modifications and alterations are also within the technical scope of the present invention.

[0077] For example, the components of the above-described embodiments can be combined in any manner, and such combinations will naturally provide the functions and effects of the individual components involved in the combination, as well as other functions and effects that will be apparent to those skilled in the art from the description herein.

[0078] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0079] The present invention can be applied to a carbon nanotube recovery device.

[0080] REFERENCE SIGNS LIST 1 CNT production apparatus (carbon nanotube production apparatus) 10 CNT production apparatus (carbon nanotube production apparatus) 11 Reaction tube 12 Heater 13 Pressure gauge 20 CNT recovery apparatus (carbon nanotube recovery apparatus) 21 Recovery chamber 21a Ceiling wall 21b Side wall 21c Side wall 22 Opening 23 Roller 30 Removal mechanism 31 Removal head 31a Tip of removal head 32 Drive unit 33 Rotating rod 34 Rotating motor 35 Cylinder 36 Connecting plate 37 Adapter 38 Sealing material 39 Passage opening 40 Plate 41 Through hole 50 Control unit

Claims

1. A carbon nanotube recovery device for recovering carbon nanotubes generated in a carbon nanotube generation device, comprising: a recovery chamber having an opening leading to the carbon nanotube generation device; and a removal mechanism for removing deposits of carbon nanotubes adhering to the wall surfaces surrounding the opening, the removal mechanism having a removal member inserted into the deposits, and a drive unit for moving the removal member between a removal position and a retracted position, the drive unit further having a configuration for rotating the removal member with the movement direction of the removal member as the rotation axis.

2. The carbon nanotube recovery device according to claim 1, wherein the tip of said removal member is not positioned on said rotation axis.

3. A carbon nanotube recovery device for recovering carbon nanotubes generated in a carbon nanotube generation device, comprising: a recovery chamber having an opening leading to the carbon nanotube generation device; and a removal mechanism for removing deposits of carbon nanotubes adhering to the wall surfaces surrounding the opening, wherein the removal mechanism has a removal member inserted into the deposits and a drive unit for moving the removal member between a removal position and a retracted position, and the drive unit is further configured to move the removal member in a direction different from the movement direction of the removal member between the removal position and the retracted position.

4. The carbon nanotube recovery device according to claim 1, wherein the removal member extends parallel to the direction of movement.

5. The carbon nanotube recovery device of claim 1, wherein the recovery chamber has a first wall portion having the opening and a second wall portion adjacent to the first wall portion, the retracted position is positioned on the second wall portion side, and a separation member is provided on the inside of the second wall portion for contacting carbon nanotubes adhering to the removal member and separating the carbon nanotubes from the removal member.

6. The carbon nanotube recovery device according to claim 5, wherein the separating member is formed with a through hole through which the removing member can pass.

7. A carbon nanotube production apparatus for producing carbon nanotubes, comprising: a carbon nanotube production apparatus for producing the carbon nanotubes; and the carbon nanotube recovery apparatus according to claim 1.

8. A carbon nanotube production apparatus as described in claim 7, further comprising a control unit for controlling the operation of the removal mechanism, the carbon nanotube generation apparatus having a reaction tube to which a raw material gas for the carbon nanotubes is supplied, and a pressure measuring unit for measuring the internal pressure of the reaction tube, the control unit being configured to execute control to move the removal member from the retracted position to the removal position when the internal pressure of the reaction tube measured by the pressure measuring unit exceeds a predetermined pressure value.

9. A carbon nanotube production apparatus as described in claim 7, further comprising a control unit for controlling the operation of the removal mechanism, the control unit being configured to execute control to move the removal member from the retracted position to the removal position when a predetermined time has elapsed since the retraction operation from the removal position to the retracted position has stopped.

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