JP4740098B2 - Carbon fiber production equipment - Google Patents

Description

  The present invention relates to a carbon fiber production apparatus.

Conventionally, after obtaining a flame-resistant strand by bundling organic precursor fibers such as polyacrylonitrile and rayon in a oxidizing atmosphere to obtain a flame-resistant strand, for example, an inert atmosphere such as nitrogen or argon An apparatus for producing carbon fiber is known which produces carbon fiber by carbonization treatment with the above. In this carbon fiber manufacturing apparatus, for example, when passing the above-mentioned yarns sequentially from a low-temperature furnace to a high-temperature furnace, the low-temperature furnace allows the yarns to pass through a yarn band arranged in parallel in a horizontal row, and enters the high-temperature furnace. At the stage of transition, the yarn band is divided into a plurality of yarn blocks, and the yarn path is changed for each yarn block. Within the yarn block, the yarns are parallel to each other in the horizontal row and between the yarn blocks. Then, after rearranging in the overlapping direction with a predetermined interval, the high temperature furnace is passed (for example, see Patent Document 1). Further, a plurality of flameproofing furnaces are arranged in the vertical direction, and a width-shifting means for vertically stretching the flameproofing strands sent from the plurality of flameproofing furnaces is provided between the flameproofing furnace and the carbonization furnace. An arrangement is disclosed (for example, see Patent Document 2).
JP-A-7-70828 JP 2003-313730 A

  However, in Patent Document 1, it is not necessary to make the inlet of the flameproofing strands of the carbonization furnace flat by rearranging the yarn blocks so that the heat efficiency of the carbonization furnace is increased. However, since the trajectory of the yarn block is changed in the horizontal direction, there is a problem that an excessive force acts on the yarn and fluff is generated to reduce the quality.

  Further, in Patent Document 2, since a plurality of flameproofing furnaces are arranged in the vertical direction (height direction), the production amount of flameproofing strands and carbon fibers can be increased, and the flameproofing furnaces at each stage are carried out. The flame-resistant strand that has been made is superior in that it can prevent the occurrence of scraping and not improve the thermal efficiency of the carbonization furnace because it does not narrow the horizontal direction (width direction). Since the flameproofing furnace is used, there is a problem in that the quality of the flameproofing strand varies depending on each flameproofing furnace, and the performance of the carbon fiber also varies. Further, when trying to make the quality of the flame resistant strands uniform, for example, it is necessary to adjust the processing temperature and the furnace length, resulting in a problem of excessive equipment or a decrease in productivity.

  Therefore, the present invention provides a carbon fiber manufacturing apparatus that can manufacture carbon fibers having high quality and uniform performance while improving productivity.

  In order to solve the above-mentioned problems, the present invention provides a carbon fiber manufacturing apparatus in which a flameproofing furnace is disposed upstream and a preliminary carbonization furnace and a carbonization furnace are sequentially disposed on the downstream side. Are arranged in the vertical direction, each provided with a first drive device that sends out the flame-resistant strands respectively carried out from the plurality of flame-proofing furnaces between the plurality of flame-proofing furnaces and the preliminary carbonization furnace, A first width-shifting means is disposed between the first drive unit and the preliminary carbonization furnace to vertically shift the flameproof strand, and the first carbonization furnace is disposed between the preliminary carbonization furnace and the carbonization furnace. A second driving device that feeds a pre-carbonized strand that has been moved up and down by one width-feeding means and processed in the pre-carbonizing furnace, and the pre-carbonization is provided between the second driving device and the carbonizing furnace; A second leveling means for leveling the strands in the vertical direction; And setting, characterized in that a third drive device for feeding the carbonized strand by the second transversely shifting means on the downstream side was a lateral move in the vertical direction is processed by the carbonization furnace of the carbonization furnace.

  By comprising in this way, even if it increases the number of flameproofing furnaces, only the dimension of an up-down direction (height direction) increases, and the installation area of a flameproofing furnace does not change. In addition, the first drive device allows the above-mentioned precursor strand to be formed by the flameproofing furnace while arbitrarily setting the raw material of the flameproofing strand passing through the flameproofing furnace, for example, the tension acting on the organic precursor strand, the passing speed, Can be flameproofed. In addition, the flameproofing strands sent out by the first driving device from the flameproofing furnaces that overlap in the vertical direction are sent to the preliminary carbonization furnace in a state of being vertically widened by the first widthing means. Can do.

  Further, the flame resistant strand can be preliminarily carbonized by the preliminary carbonization furnace while arbitrarily setting the tension, the passing speed, etc. acting on the preliminary carbonized strand by the second driving device. Furthermore, since each flameproofing strand can be width-reduced again in the vertical direction by the second widthing means and sent to the carbonization furnace, the inlet of the preliminary carbonized strand of the carbonization furnace can be reduced. . In addition, since the pre-carbonized strand is not widened in the horizontal direction, no excessive force acts on the pre-carbonized strand. Furthermore, the carbonized strand (carbon fiber) can be obtained by carbonizing the preliminary carbonized strand by a carbonization furnace while arbitrarily setting the tension acting on the preliminary carbonized strand by the third driving device.

According to the present invention, it is possible to increase the number of installed flameproofing furnaces without increasing the installation area of the flameproofing furnace, so that the flameproofing is an intermediate product of carbon fiber while preventing the equipment from becoming excessive. It is possible to easily increase the production amount of the activated strand and improve the productivity of the carbon fiber.
In addition, since the tension, passage speed, etc. acting on the raw material of the flame resistant strand that passes through each flame resistant furnace can be arbitrarily set, the tension, passage speed, etc. of the raw material are appropriately adjusted for each flame resistant furnace, and the flame resistant strand Quality can be improved and the quality can be made uniform.
Similarly, by arbitrarily setting the tension, the passing speed, etc. by the second and third driving devices, the quality of the preliminary carbonized strand, the preliminary carbonized strand processed by the carbonizing furnace, and the carbonized strand are improved. , Quality can be made uniform. Also, different types of carbon fibers can be manufactured by controlling different tensions, passage speeds, etc. for each flameproofing strand sent from each flameproofing furnace, and production can be rationalized.

Furthermore, since the inlet of the flameproofing strand of the preliminary carbonization furnace can be made smaller by shifting the flameproofing strand in the vertical direction by the first widthening means, the preliminary carbonization furnace is made compact and the thermal efficiency is improved. Can be improved. Moreover, since an excessive force in the horizontal direction does not act on the flame resistant strand, it is possible to prevent the occurrence of scuffing on the flame resistant strand. Similarly, since the pre-carbonized strands can be moved up and down by the second width-shifting means, the carbonization furnace can be made compact, the thermal efficiency of the carbonization furnace can be improved, and the occurrence of cracks on the pre-carbonized strands can be generated. Can be prevented.
Therefore, it is possible to produce a carbon fiber having high quality and uniform performance while improving the productivity of the carbon fiber.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing the overall configuration of the carbon fiber manufacturing apparatus according to the present embodiment. As shown in FIG. 1, the carbon fiber manufacturing apparatus includes a plurality of flameproofing furnaces 1 and 2 on the upstream side (the left side in the figure). The flameproofing furnaces 1 and 2 are formed in a box shape having a rectangular section by an outer wall and a heat insulating material, and are provided with a heating device for heating the inside of the furnace, a supply device for oxidizing gas, a gas exhaust device and the like (not shown). Here, the high temperature part of the flameproofing furnaces 1 and 2 is formed of a high heat resistant material such as a carbon material, and the other part is formed of a structural material such as iron or stainless steel.

  The flameproofing furnaces 1 and 2 are arranged in a vertically stacked state (vertical direction in the figure). In order to feed precursor strands 3 and 4 bundled with carbon fiber raw materials, for example, precursor fibers such as polyacrylonitrile and rayon into the furnace, the outer wall on the upstream side of the flameproofing furnaces 1 and 2 has a first Inlet 1a, 2a is provided. The first inlets 1a and 2a are opened in the form of slits having a width in the direction perpendicular to the paper surface at the upper part of the outer wall on the upstream side of the flameproofing furnaces 1 and 2. On the outer wall on the downstream side (right side in the figure) of the flameproofing furnaces 1 and 2, first outlets 1 b and 2 b are provided to face the first inlets 1 a and 2 a. The first outlets 1b and 2b are provided in the same slit shape as the first inlets 1a and 2a so that the precursor strands 3 and 4 sent from the first inlets 1a and 2a can be sent out of the furnace. It has been.

  Similar to the first inlets 1a and 2a, the second inlets 1c and 2c are provided below the first outlets 1b and 2b so that the precursor strands 3 and 4 can be fed into the furnace. . On the downstream side outside the flameproofing furnaces 1 and 2, the first rollers 5 a and 6 a correspond to the first delivery port 1 b and the second delivery port 1 c so that the precursor strands 3 and 4 can be folded back in the reverse direction. In addition, the rotary shaft is provided so as to be rotatable with the rotation axis substantially perpendicular to the paper surface. A first path for heat-treating the precursor strands 3 and 4 by these first inlets 1a and 2a, first outlets 1b and 2b, and first rollers 5a and 6a is formed in a substantially horizontal direction (left and right direction in the figure). ing.

Second inlets 1d and 2d formed on the downstream side of the flameproofing furnaces 1 and 2 below the first inlets 1a and 2a on the outer wall on the upstream side of the flameproofing furnaces 1 and 2 1c and 2c are provided facing. The third inlets 1e and 2e are provided below the second outlets 1d and 2d in the same manner as the first inlets 1a and 2a. The second rollers 5b and 6b are provided on the upstream side outside the flameproofing furnaces 1 and 2 corresponding to the second delivery ports 1d and 2d and the third delivery ports 1e and 2e in the same manner as the first rollers 5a and 6a. It has been. A second path similar to the first path is formed below the first path by the second inlets 1c and 2c, the second outlets 1d and 2d, and the second rollers 5b and 6b. As described above, the flameproofing furnaces 1 and 2 are formed with a plurality of paths in the vertical direction by the plurality of inlets 1a, 2a,..., The outlets 1b, 2b, and the rollers 5a, 5b,.
On the outside of the inlets 1a, 2a,... And the outlets 1b, 2b,... Of each path, seal equipment (not shown) such as an air curtain, for example, penetrates the outside air into the furnace and goes from the inside of the furnace to the outside. It is provided so that leakage of gas can be prevented.

  The conveying rollers 7a and 8a convey the flame resistant strands 9 and 10 processed in the flame resistant furnaces 1 and 2 to the downstream side of the outlets 1j and 2j of the final pass of the flame resistant furnaces 1 and 2, respectively. In order to achieve this, each of the outlets 1j, 2j is provided so as to be rotatable with the rotation axis substantially perpendicular to the paper surface. On the downstream side of the transport roller 7a, a transport roller 7b is provided in a similar manner so as to be separated in a substantially horizontal direction. Further, on the downstream side of the transport roller 8a, a transport roller 8b is similarly provided so as to be spaced upward. Here, the conveying roller 7b corresponds to the lowermost stage of the first driving device 21 described later, and the conveying roller 8b is provided to correspond to the uppermost stage of the driving roller of the first driving device 22 described later.

  On the downstream side of the conveying rollers 7b and 8b, the first driving devices 21 and 22 composed of a plurality of driving rollers are respectively arranged vertically corresponding to the flameproofing strands 9 and 10 carried out from the flameproofing furnaces 1 and 2, respectively. Is provided. As shown in FIG. 1, the first driving devices 21 and 22 are provided with two driving rollers spaced apart in a substantially horizontal direction, and the pair of driving rollers is separated from each other in three stages in the vertical direction. There are a total of six rollers. The rotation shafts of the drive rollers of the first drive devices 21 and 22 are substantially perpendicular to the paper surface, and are connected to a drive device (not shown) including, for example, a motor, a gear, a controller, and the like, and can be freely controlled in rotation.

  A first width adjusting means 60 is provided on the downstream side of the first driving devices 21 and 22. In the first width adjusting means 60, first width adjusting rollers 7c, 8c are arranged apart from each other in the vertical direction, and second width adjusting rollers 7d, 8d are provided close to the vertical direction on the downstream side thereof. . The first width adjusting rollers 7c and 8c respectively correspond to the uppermost driving roller of the first driving device 21 arranged on the upper side of the drawing and the lowermost driving roller of the first driving device 22 arranged on the lower side of the drawing. It is provided at the position. Each of the width adjusting rollers 7c, 8c, 7d, 8d is rotatably provided with a rotation axis substantially perpendicular to the paper surface. Here, the second width adjusting rollers 7d and 8d are provided corresponding to the position and dimensions of the flameproof strand inlet 40a of the preliminary carbonization furnace 40 described later.

  A preliminary carbonization furnace 40 having a rectangular cross section and a cylindrical shape is provided on the downstream side of the first width adjusting means 60. Like the flameproofing furnaces 1 and 2, the preliminary carbonization furnace 40 is formed in a box shape having a rectangular cross section by an outer wall and a heat insulating material, and is a heating device for heating the inside of the furnace, a supply device for inert gas, a gas exhaust device, etc. Etc. (not shown). The preliminary carbonization furnace 40 is formed of the same material as the flameproofing furnaces 1 and 2. In addition, a flameproof strand inlet 40 a that receives the flameproof strands 9 and 10 flameproofed by the flameproofing furnaces 1 and 2 is provided at a substantially central portion of the outer wall on the upstream side of the preliminary carbonization furnace 40. . In addition, a pre-carbonized strand outlet 40b is provided on the outer wall on the downstream side of the preliminary carbonization furnace 40 so as to face the flameproof strand inlet 40a. Like the flameproofing furnaces 1 and 2, outside of the flameproofing strand inlet 40 a and the preliminary carbonized strand outlet 40 b of the preliminary carbonization furnace 40, the outside air enters the furnace and enters the outside from the furnace. Sealing equipment (not shown) for preventing gas leakage is provided.

On the downstream side of the preliminary carbonization furnace 40, transport rollers 11a and 12a are arranged close to each other in the vertical direction corresponding to the preliminary carbonization strand delivery port 40b.
The transport rollers 11a and 12a are rotatably provided so that their rotation axes are substantially perpendicular to the paper surface so that the pre-carbonized strands 31 and 32 processed by the pre-carbonization furnace 40 can be transported. A similar transport roller 11b is disposed on the downstream side of the transport roller 11a so as to be spaced apart from the upper side, and is provided corresponding to the uppermost stage of the second drive device 23 described later. Second drive units 23 and 24 are provided on the downstream side of the transport rollers 11a, 11b, and 12a of the pre-carbonized strands 31 and 32, respectively.

Similarly to the first drive devices 21 and 22, the second drive devices 23 and 24 are provided with a pair of drive rollers that are spaced apart in the horizontal direction and are spaced apart from each other in three stages in the vertical direction. On the downstream side of the second driving devices 23 and 24, a second width adjusting means 70 including a plurality of width adjusting rollers 11c, 12b, and 12c is provided.
The second width adjusting means 70 is provided with a first width adjusting roller 12 b corresponding to the lowermost driving roller of the second driving device 24. Also, a pair of second width adjusting rollers 11c and 12c are provided close to each other on the upper side on the downstream side of the first width adjusting roller 12b. The second width adjusting rollers 11c and 12c are provided corresponding to a preliminary carbonized strand feed port 50a of the carbonization furnace 50 described later. A cylindrical carbonization furnace 50 having a rectangular cross section is provided on the downstream side of the second width adjusting rollers 11c and 12c.

  Similarly to the preliminary carbonization furnace 40, the carbonization furnace 50 is formed into a box shape having a rectangular cross section by an outer wall and a heat insulating material, etc., and a heating device for heating the inside of the furnace, a supply device for inert gas, a gas exhaust device, etc. (Not shown). The carbonization furnace 50 is formed of the same material as that of the preliminary carbonization furnace 40. Further, a pre-carbonized strand inlet 50 a that receives the pre-carbonized strands 31 and 32 processed by the pre-carbonized furnace 40 is provided at a substantially central portion of the outer wall on the upstream side of the carbonizing furnace 50. Further, a carbonized strand outlet 50b is provided on the outer wall on the downstream side of the carbonization furnace 50 so as to face the preliminary carbonized strand inlet 50a. As with the preliminary carbonization furnace 40, outside air is introduced into the outside of the preliminary carbonization strand inlet 50 a and the carbonized strand outlet 50 b of the carbonization furnace 50 and gas from the inside of the furnace to the outside is introduced. Sealing equipment (not shown) for preventing leakage is provided.

  On the downstream side of the carbonization furnace 50, carbonized strand transport rollers 13a, 13b, and 14a are provided in the same manner as the preliminary carbonized strand transport rollers 11a, 11b, and 12a on the downstream side of the preliminary carbonization furnace 40. Yes. Moreover, the 3rd drive devices 25 and 26 are provided similarly to the 2nd drive devices 23 and 24 in the downstream of the rollers 13a, 13b, and 14a for carbonized strand conveyance. On the downstream side of the third driving devices 25 and 26, the carbon fiber shipping rollers 13c and 14b correspond to the lowermost driving rollers of the third driving devices 25 and 26, and are separated from each other in a substantially horizontal direction. Is provided so as to be rotatable perpendicular to the paper surface.

  As described above, in the carbon fiber manufacturing apparatus according to the present embodiment, the flameproofing furnaces 1 and 2 are arranged on the upstream side, and the first between the flameproofing furnaces 1 and 2 and the preliminary carbonization furnace 40. Drive devices 21 and 22 are provided, and a first shifting means 60 is disposed between the first drive devices 21 and 22 and the preliminary carbonization furnace 40, and a first shift means 60 is provided between the preliminary carbonization furnace 40 and the carbonization furnace 50. 2 driving devices 23, 24 are provided, a second width adjusting means 70 is disposed between the second driving devices 23, 24 and the carbonization furnace 50, and the third driving device 25 is disposed downstream of the carbonization furnace 50. , 26 are provided.

Next, the operation of this embodiment will be described.
As shown in FIG. 1, precursor strands 3 and 4 in which precursor fibers are bundled with a width in a direction perpendicular to the paper surface are passed from first inlets 1 a and 2 a of each flameproofing furnace 1 and 2 into each furnace. Send in. The insides of the flameproofing furnaces 1 and 2 are heated by a heating device (not shown) and maintained at a temperature at which the precursor fibers can be flameproofed. Further, the oxidizing gas supply device (not shown) supplies the oxidizing gas into the furnace, and the sealing equipment (not shown) prevents intrusion of outside air into the furnace and leakage of the gas from the inside of the furnace to the outside. . The precursor strands 3 and 4 sent into the furnace are heated in an oxidizing atmosphere and sent out of the furnace from the first delivery ports 1b and 2b. The precursor strands 3 and 4 which are heated through the first pass and are sent out of the furnace are wound by the first rollers 5a and 6a and turned back in the opposite direction from the second feeding ports 1c and 2c. It is again sent into the flameproofing furnaces 1 and 2.

The precursor strands 3 and 4 sent into the furnace are heated again and sent out of the furnace through the second delivery ports 1d and 2d. The precursor strands 3 and 4 that have passed through the second pass are repeatedly passed through the same pass a plurality of times, repeatedly entering and exiting the flame-proofing furnaces 1 and 2, and gradually becoming flame-resistant while meandering in the furnace. . At this time, a gas containing a harmful substance generated by heating is discharged out of the furnace by an exhaust device (not shown) and is rendered harmless. The precursor strands 3 and 4 that have undergone the flameproofing treatment are each carried out of the furnace as flameproofing strands 9 and 10 from the outlets 1j and 2j in the final pass.
At this time, two flameproofing furnaces 1 and 2 are stacked in the vertical direction. Therefore, compared with the case where only one is installed, the production amount of the flameproof strands 9 and 10 which are intermediate products of carbon fibers can be easily increased. Therefore, the productivity of carbon fibers can be easily improved.

Moreover, even if the number of flameproofing furnaces 1 and 2 is increased, the vertical area (height direction) of the flameproofing furnaces 1 and 2 only increases, and the installation area of the flameproofing furnaces 1 and 2 does not change. . Therefore, since the number of installed flameproofing furnaces 1 and 2 can be increased without increasing the installation area of the flameproofing furnaces 1 and 2, it is possible to prevent the facility from becoming excessive.
Further, since the flameproof strands 9 and 10 carried out from the flameproofing furnaces 1 and 2 can be stacked in the vertical direction, the spare carbons are arranged as in the case where the flameproof strands 9 and 10 are arranged in the direction perpendicular to the paper surface. It is not necessary to unnecessarily increase the width in the direction perpendicular to the paper surface of the inlet 40a of the flameproofing strands 9 and 10 of the conversion furnace 40. Therefore, the inlet 40a of the flameproof strands 9 and 10 can be made small, and the thermal efficiency of the preliminary carbonization furnace 40 can be improved. Further, the width of the preliminary carbonization furnace 40 in the direction perpendicular to the paper surface can be reduced, the preliminary carbonization furnace 40 can be made compact to improve the thermal efficiency, and the installation space can be reduced.

  Further, when the precursor strands 3 and 4 pass through the flameproofing furnaces 1 and 2, tension is applied to the precursor strands 3 and 4 by the first driving devices 21 and 22. That is, the flameproofing strands 9 and 10 carried out of the flameproofing furnaces 1 and 2 from the outlets 1j and 2j of the flameproofing furnaces 1 and 2 after the flameproofing process are finished are first transported by the transport rollers 7a, 7b, 8a and 8b. It is led to the lowermost and uppermost stages of the driving rollers of the driving devices 21 and 22. Of the pair of drive rollers arranged in a plurality of stages in the substantially horizontal direction, the flameproof strands 9 and 10 are stretched over one side in the vertical direction of the first-stage upstream drive roller, and the downstream drive roller From the other side, the flameproof strands 9 and 10 are wound around the downstream drive roller and folded back. And among the pair of driving rollers of the next stage arranged in the up-and-down direction, it is wound around the upstream driving roller and folded back.

  This is repeated, and the flameproof strands 9 and 10 are wound around each drive roller while being folded in a plurality of times so as to meander between a pair of drive rollers arranged in a plurality of stages in the vertical direction. To do. By rotating each drive roller in this state, power is applied to the flame resistant strands 9 and 10 by the frictional force between each drive roller and the flame resistant strands 9 and 10, and the flame resistant strands 9 and 10 are downstream. Sent out. Thereby, tension is applied to the precursor strands 3 and 4 passing through the flameproofing furnaces 1 and 2. At this time, the rotational speed, rotational torque, and the like of each driving roller of the first driving devices 21 and 22 can be arbitrarily set by a driving device (not shown).

Therefore, by controlling the rotation of each drive roller of the first drive units 21 and 22, the tension acting on the precursor strands 3 and 4 passing through the flameproofing furnaces 1 and 4 and the passing speed are arbitrarily set. The precursor strands 3 and 4 can be heat-treated by the flameproofing furnaces 1 and 2.
Therefore, even when the conditions are different for each of the plurality of flameproofing furnaces 1 and 2, the passage speed, tension, and the like of the precursor strands 3 and 4 are appropriately adjusted for each flameproofing furnace 1 and 2, Quality can be improved and quality can be made uniform. On the other hand, different varieties of carbon fibers with different heating conditions can be produced by varying the passing speed, tension, and the like for each of the precursor strands 3 and 4 passing through the flameproofing furnaces 1 and 2. As a result, it is possible to easily cope with multi-product production and rationalize production.

  In addition, the first driving devices 21 and 22 are configured such that each pair of driving rollers is arranged in a plurality of stages, so that the installation space of the first driving devices 21 and 22 is not increased more than necessary. The contact area between the drive roller and the flameproof strands 9 and 10 can be increased. Therefore, the tension can be efficiently applied without applying an excessive force to the flameproof strands 9 and 10. Therefore, generation | occurrence | production of the crack of the flameproofing strands 9 and 10 can be prevented, preventing the facility from becoming excessive, and the quality of carbon fiber can be improved.

Furthermore, the flameproofing strands 9 and 10 sent to the downstream side by the first driving devices 21 and 22 are respectively wound around the first width adjusting rollers 7c and 8c of the first width adjusting means 60, and the second width adjusting roller 7d. 8d, the vertical intervals are made closer to each other, and are brought close to each other and fed into the preliminary carbonization furnace 40.
Thereby, compared with the case where each flameproofing strands 9 and 10 are not brought near, the height of the feed port 40a of the flameproofing strands 9 and 10 of the preliminary carbonization furnace 40 can be reduced. Further, since the vertical spacing between the flameproof strands 9 and 10 is reduced, the vertical dimension of the preliminary carbonization furnace 40 can be reduced, and the preliminary carbonization furnace 40 can be made compact. Therefore, the thermal efficiency of the preliminary carbonization furnace 40 can be improved, and the installation space can be reduced.
Moreover, since the horizontal force of the flame resistant strands 9 and 10 does not act on the flame resistant strands 9 and 10 by increasing the vertical width of the flame resistant strands 9 and 10, it prevents the flame resistant strands 9 and 10 from being cracked. In addition, the quality of the carbon fiber can be improved.

Similarly to the flameproofing furnaces 1 and 2, the preliminary carbonization furnace 40 is maintained at a temperature required for carbonization of the flameproofing strands 9 and 10 by a heating device (not shown), and by an inert gas supply device (not shown). The supplied inert gas fills the furnace, and sealing equipment (not shown) prevents the intrusion of outside air into the furnace and the leakage of gas from the inside of the furnace to the outside. The flameproof strands 9 and 10 fed into the preliminary carbonization furnace 40 are heated in an inert gas atmosphere, and carbonization proceeds. As the carbonization proceeds, the flame-resistant strands 9 and 10 that have been preliminarily carbonized are sent out of the furnace as the pre-carbonized strands 31 and 32 from the outlet 40b.
At this time, the second drive devices 23 and 24 configured in the same manner as the first drive devices 21 and 22 can arbitrarily set the tension, the passing speed, etc. acting on the flameproof strands 9 and 10 passing through the preliminary carbonization furnace 40. While setting, the flameproofing strands 9 and 10 can be carbonized by the preliminary carbonization furnace 40. Therefore, by installing the second driving devices 23 and 24, it is possible to obtain the same effect as that obtained when the first driving devices 21 and 22 described above are installed.

  The preliminary carbonized strands 31 and 32 sent out of the furnace from the delivery port 40b of the preliminary carbonization furnace 40 are respectively guided to the uppermost stages of the drive rollers of the second drive units 23 and 24 by the transport rollers 11a, 11b, and 12a. Then, power is applied by the second driving devices 23 and 24 and the fuel is sent to the downstream side. The pre-carbonized strand 32 fed to the downstream side of the second drive units 23, 24 is wound around the first width-shifting roller 12 of the second width-shifting means 70, and further provided in the vicinity of the upper and lower sides. By being wound around the width adjusting roller 12 c, the vertical distance between the preliminary carbonized strands 31 and 32 is increased and sent to the carbonization furnace 50.

Thereby, similarly to the 1st width adjustment means 60, compared with the case where the preliminary carbonization strands 31 and 32 are not width-adjusted, the dimension of the feed port 50a of the carbonization furnace 50 in the figure up-down direction can be made small. Further, since the pre-carbonized strands 31 and 32 are not shifted in the horizontal direction, an excessive force in the horizontal direction does not act on the pre-carbonized strands 31 and 32.
Therefore, similarly to the case where the first width adjusting means 60 is installed, the carbonizing furnace 50 is made compact by installing the second width adjusting means 70, the thermal efficiency of the carbonizing furnace 50 is improved, and the reserve carbon is further increased. It is possible to improve the quality of the carbon fiber by preventing the generation of cracks on the strands 31 and 32.

  Similarly to the preliminary carbonization furnace 40, the carbonization furnace 50 is maintained at a temperature required for carbonization of the preliminary carbonized strands 31 and 32 by a heating device (not shown), and is supplied by an inert gas supply device (not shown). The inside of the furnace is filled with the inert gas, and the sealing equipment (not shown) prevents intrusion of outside air into the furnace and leakage of gas from the inside of the furnace to the outside. The pre-carbonized strands 31 and 32 sent into the carbonization furnace 50 are heated in an inert gas atmosphere, and carbonization proceeds. The pre-carbonized strands 31 and 32 that have been carbonized and are completely carbonized are sent out of the furnace 50 b as carbonized strands 33 and 34 (carbon fiber yarns), and the carbonized strand shipping roller. It is conveyed downstream by 13c, 14b.

At this time, similarly to the first driving devices 21 and 22 and the second driving devices 23 and 24, the third driving devices 25 and 26 arbitrarily set the tension, the passing speed, and the like acting on the preliminary carbonized strands 31 and 32. However, the pre-carbonized strands 31 and 32 can be carbonized by the carbonization furnace 50 to obtain the carbonized strands 33 and 34. Therefore, by installing the third driving devices 25 and 26, it is possible to obtain the same effect as when the first driving devices 21 and 22 and the second driving devices 23 and 24 are installed.
As described above, according to the present embodiment, it is possible to manufacture carbon fibers having high quality and uniform performance while improving the productivity of carbon fibers.

The present invention is not limited to the above-described embodiment, and three or more flameproofing furnaces are stacked in the vertical direction, and the flameproofing strands taken out from each flameproofing furnace are vertically widened via a driving device. Can be sent to the subsequent process. A plurality of preliminary carbonization furnaces and carbonization furnaces may be stacked in the vertical direction.
In addition, when stacking the furnaces in the vertical direction, the furnaces may be stacked slightly shifted in the horizontal direction rather than in the complete vertical direction. By arranging in this way, for example, each furnace can be arranged according to the restriction of the installation location, and the carbon fiber manufacturing apparatus can be installed in a limited space.

  Moreover, it is good also as a structure which uses the drive roller of each drive device instead of multiple. Further, when a plurality of driving rollers are arranged, the pair of driving rollers arranged on the upstream side and the downstream side may be arranged in a staggered manner by shifting in a vertical direction rather than horizontally. By arrange | positioning in this way, the contact area of each strand and each drive roller can be reduced, and the frictional force which acts on each strand can be made small.

The number of width adjusting rollers of the width adjusting means may be arbitrary as long as each strand can be adjusted in the vertical direction.
Moreover, the introduction position of each strand to the drive roller of each drive device may be from either the uppermost stage or the lowermost stage. At this time, by changing the introduction position to each drive device, the passage route of each strand between the furnaces can be changed, and the distance traveled by each strand between the furnaces can be adjusted.

  In addition, since the pre-carbonized strands 31 and 32 subjected to the pre-carbonization treatment in the pre-carbonization furnace 40 have a reduced strand volume, when passing through the subsequent driving devices, the strands at the upper and lower stages are moved by the respective strand transport rollers. It is also possible to make the driving devices common by shifting the widths. For example, the preliminary carbonization strands 31 and 32 that have been subjected to the preliminary carbonization treatment after passing through the preliminary carbonization furnace 40 are widened to share the second drive devices 23 and 24, or the carbonization after passing through the carbonization furnace 50. It is possible to make the third driving devices 25 and 26 common by bringing the strands 33 and 34 (carbon fiber yarns) closer together.

  Further, the driving device is not limited to the driving roller, and a nip roller or the like can be appropriately selected. The width adjusting means is not limited to the roller, and any structure can be used as long as it can be adjusted in the vertical direction, such as a guide rod.

  In addition, as an example of a sealing device provided in the preliminary carbonization furnace 40 and the carbonization furnace 50, a seal chamber having a slit through which the strand passes is provided in at least one of each strand feeding port and its feeding port side. By supplying or sucking gas in the chamber, it is possible to suppress outflow of inert gas to the outside of the furnace and inflow of outside air. Similarly, a seal device having an air curtain means for blowing an inert gas toward the strand is provided, or a seal chamber having a slit through which the strand passes is provided, gas is sucked in the seal chamber, and the strand of the seal chamber After passing through the inlet or the furnace, provide an air curtain for external blowing on the outlet side of the seal chamber, or provide the above-mentioned seal chamber, and sucking gas in this seal chamber and The same effect can be obtained by providing an air curtain for blowing inert gas. Furthermore, the amount of energy required for heating in the preliminary carbonization treatment and the carbonization treatment can be reduced by using the heated inert gas for the air curtain.

  Similarly, in the direction orthogonal to the running direction of the strands, a plurality of opposed throttle pieces are arranged above and below each strand to provide an expansion chamber, and the pressure loss generated for each throttle piece acts as a resistance to the gas flow. Also, a labyrinth seal device that reduces the amount of outflow and inflow gas may be used. Further, the above-described expansion chamber may have an inert gas outlet, and the labyrinth seal device may be configured to prevent outside air from flowing into the furnace and inert gas from flowing out of the furnace. In addition, a flat floor surface and an expansion chamber composed of a plurality of throttle pieces are provided above the flat floor surface, and the outside air is blown toward the flat floor surface from the inert gas outlet in the expansion chamber. It may be a labyrinth seal device having a structure that prevents inflow into the furnace and outflow of inert gas to the outside of the furnace.

The sealing device provided in the preliminary carbonization furnace 40 and the carbonization furnace 50 is not limited to the above-described sealing device, and any sealing device can be used as long as the sealing device can handle multiple stages of firing.
Furthermore, the preliminary carbonization furnace 40 may be omitted, and various modifications may be made without departing from the scope of the present invention.

The schematic sectional drawing showing the whole structure of the manufacturing apparatus of the carbon fiber in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flame resistance furnace 2 Flame resistance furnace 9 Flame resistance strand 10 Flame resistance strand 21 1st drive device 22 1st drive device 23 2nd drive device 24 2nd drive device 25 3rd drive device 26 3rd drive device 31 Preliminary carbonization Strand 32 Preliminary carbonized strand 33 Carbonized strand 34 Carbonized strand 40 Preliminary carbonization furnace 50 Carbonization furnace 60 First width adjusting means 70 Second width adjusting means

Claims (1)

An apparatus for producing carbon fiber comprising a flameproofing furnace on the upstream side, a preliminary carbonization furnace on the downstream side, and a carbonizing furnace in sequence,
A plurality of the flameproofing furnaces are arranged in the vertical direction, and a first drive device that sends out the flameproofing strands respectively transported from the plurality of flameproofing furnaces between the plurality of flameproofing furnaces and the preliminary carbonization furnace Each of which is provided, and between the first driving device and the preliminary carbonization furnace, a first width-shifting means for width-shifting the flameproof strand in the vertical direction is disposed, and the preliminary carbonization furnace and the carbonization furnace A second drive device is provided between the second drive device and the carbonization furnace, wherein the second drive device sends out the pre-carbonized strand that has been moved up and down by the first width-shifting means and processed in the preliminary carbonization furnace. A second width-shifting means for shifting the preliminary carbonized strand in the vertical direction is disposed, and the secondary carbonized strand is shifted in the vertical direction by the second width-shifting means on the downstream side of the carbonization furnace and processed in the carbonization furnace. Third drive device for feeding out carbonized strands Apparatus for manufacturing carbon fiber characterized by comprising.

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