JP2014221956A - Heat treatment apparatus, and method for producing flame-resistant fiber by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment apparatus which is concerned with quality improvement and has an inexpensive equipment cost, and to provide a method for producing a flame-resistant fiber by using the heat treatment apparatus.SOLUTION: The heat treatment apparatus has the following structures (1)-(6) and is constituted so that a heat-treating gas is blown against both surfaces of a fiber bundle in parallel. The structure (1) includes a heat treatment chamber 2 and two series of circulation flow passages 7, 7' arranged on the inside and outside of the heat treatment chamber. The structure (2) includes a plurality of blowing nozzles 3, 3' and two suction parts 4, 4' all of which are communicated with the two series of circulation flow passages. The structure (3) is that the blowing nozzles communicated respectively with the first series of circulation flow passage are disposed on the upside and downside of a traveling yarn 8 in the vicinity of an inlet/outlet portion at one edge of the heat treatment chamber. The structure (4) is that the blowing nozzles communicated respectively with the second series of circulation flow passage are disposed on the upside and downside of the yarn in the vicinity of an inlet/outlet portion at the other edge of the heat treatment chamber. The structure (5) is that two suction parts are formed by opening the wall of a central part thereof so as to be opposed directly to the lateral or vertical direction of the yarn. The structure (6) is that the circulation flow passage includes heating means 5 or 5' and hot air sending means 6 or 6' and is disposed on the outside of the heat treatment chamber.

Description

  The present invention relates to a heat treatment apparatus suitable for use in the production of flame-resistant fibers and a method for producing flame-resistant fibers using the heat treatment apparatus.

As a method for producing a carbon fiber, a method of carbonizing a precursor fiber bundle of carbon fibers after performing a flame resistance treatment is widely known.
As the flameproofing treatment during the production of the carbon fiber, for example, a method of heat-treating the precursor fiber with hot air in a heat treatment chamber in an oxidizing atmosphere is employed.

In the flameproofing treatment, an oxidation reaction accompanied by heat generation of the precursor fiber bundle (hereinafter referred to as yarn) occurs, so that the single fibers are likely to be fused by hot air in the heat treatment apparatus or a large amount of heat generation accompanying the oxidation reaction. Therefore, in general, a method of removing the heat accumulation of the yarn by increasing the circulating air volume and the air speed in the heat treatment apparatus is employed.
Further, in order to increase productivity, it is necessary to process a large amount of yarn with a long apparatus while maintaining high heat transfer performance.
Therefore, in the flameproof heat treatment apparatus disclosed in Japanese Patent Application Laid-Open No. 2008-144293 (Patent Document 1), a gas introduction unit that blows an oxidizing atmosphere gas substantially orthogonal to the traveling direction of the polyacrylonitrile fiber bundle, A gas discharge portion for discharging the oxidizing atmosphere gas provided opposite to the gas introduction portion, and an opening capable of containing a circle having a diameter of 10 mm in consideration of blockage of the hot air nozzle in the gas introduction portion. A perforated plate is provided. Further, according to Japanese Patent Laid-Open No. 2002-161441 (Patent Document 2), the hot air introducing section and the hot air deriving section are alternately arranged in the horizontal direction along the running direction of the plurality of yarns running in the heat treatment chamber in the horizontal direction. An installed flameproof heat treatment apparatus is disclosed.

  Furthermore, in the heat treatment furnace disclosed in Japanese Patent Application Laid-Open No. 62-228865 (Patent Document 3), there are provided a blowout port for blowing hot air in a direction parallel to the yarn transfer direction and an intake port for discharging hot air in the heat treatment chamber. It is provided above and below the yarn passage. Further, in US Pat. No. 4,515,561 (Patent Document 4), a blow nozzle that blows hot air in the center of the heat treatment chamber is provided, and hot air is blown toward both ends of the heat treatment chamber in a direction parallel to the running direction of the yarn. A flameproof furnace that sucks and circulates hot air from a suction nozzle is disclosed.

JP 2008-144293 A Japanese Patent Laid-Open No. 2002-161441 JP-A-62-2228865 US4515561

  However, Patent Document 1 relates to a heat treatment apparatus that supplies hot air perpendicularly to a yarn having a blowing air velocity in a range of 0.3 m / s to 1.5 m / s, and at the same time controls the air velocity uniformly. When the air volume is increased, the yarn is easily cut and entanglement between adjacent fibers occurs frequently.

Further, Patent Document 2 relates to a heat treatment apparatus that alternately blows hot air from both sides of the yarn in the lateral direction. When the air volume increases, the single fibers in the yarn rub against each other and fluff is generated, resulting in a reduction in quality. There is a possibility of inviting.

Patent Document 3 relates to a heat treatment furnace that blows hot air in a direction parallel to the yarn transfer direction, and can suppress the yarn from shaking due to the hot air and increase the air volume.
However, every time the yarn is folded and passes through the heat treatment chamber, it is alternately exposed to forward wind and countercurrent with different firing conditions, and the longer the apparatus is, the more likely the deterioration of the firing efficiency becomes more prominent.

  Further, Patent Document 4 relates to a flameproofing furnace that blows hot air from a blowing nozzle installed at the center toward both ends in a direction parallel to the yarn transfer direction, but passes between the blowing nozzles in the center of the furnace. When it does, it becomes a wind speed fall area | region of a hot air, and possibility that a thread | yarn will cut | disconnect increases. In addition, by installing the blowing nozzle in the center, there is a risk of scratching from the suspension of the yarn when passing between the nozzles, and there is a possibility that the length of the device becomes longer.

  The object of the present invention is to increase the processing speed and air volume to obtain high productivity from its high heat transfer performance, and to supply heat treatment gas in parallel to both sides of the yarn to provide flame resistance by parallel flow heat treatment In the apparatus, by making the inside of the furnace a simple structure, it is possible to improve the quality by preventing fraying and suppressing the generation of fluff, and further reducing the equipment cost. It is in providing the manufacturing method of the flame-resistant fiber used.

In the heat treatment chamber of the present invention, a heat treatment apparatus for continuously heat-treating a yarn by spraying heat treatment gas in parallel from both sides to each yarn that reciprocates a plurality of times in the horizontal direction in the interior includes the following aspects: To do.
[1]
(1) A heat treatment chamber having the yarn entry / exit at both ends and two circulation channels for circulating the heat treatment gas inside and outside the heat treatment chamber are provided.
(2) The heat treatment chamber is provided with a plurality of blowing nozzles respectively connected to the two circulation channels and two suction portions respectively connected to the two circulation channels.
(3) Among the two circulation passages, the plurality of blowout nozzles communicating with the circulation passage of the first system are provided on the upper and lower sides of the traveling yarn in the vicinity of the entrance / exit at one end of the heat treatment chamber. Be placed.
(4) The plurality of blowout nozzles communicating with the second system circulation channel out of the two systems circulation channels are arranged in the vicinity of the entrance and exit of the other end of the heat treatment chamber. Placed in.
(5) The two suction portions open to the wall in the center of the heat treatment chamber so as to face the lateral direction or the vertical direction of the running yarn.
(6) The circulation channel includes gas heating means and hot air blowing means, and is disposed outside the heat treatment chamber.

[2] In the heat treatment apparatus, the distance between the center point of each suction portion and the midpoint of the line segment passing through the center point and extending in the direction in which the yarn travels is determined by the yarn in the heat treatment chamber. It is preferable that it is located within the range of 0.1 times the length in the traveling direction.

[3] In the heat treatment apparatus, the two suction portions have the same rectangular shape and are arranged so as to face the transverse direction of the running yarn, and the height of each suction portion is equal to the height of the heat treatment chamber. When the frontage area is A and the cross-sectional area of the surface orthogonal to the yarn traveling in the heat treatment chamber is B, it is preferable that A and B satisfy the following relational expression.
0.5 × B ≦ A ≦ 1.0 × B

[4] In the heat treatment apparatus, a perforated plate is preferably installed in the suction part.

[5] In the heat treatment apparatus, in the vicinity of the suction portion, there are a plurality of openings through which the yarn passes in two passages on one end side and the other end side of the heat treatment chamber. It is preferable to install a control plate that becomes higher toward the center so as to suppress wind speed spots of the heat treatment gas.

[6] The heat treatment apparatus is preferably used for heat-treating the carbon fiber precursor fiber bundle to produce flame-resistant fibers.

  According to the heat treatment apparatus of the present invention and the flameproof fiber manufacturing method using the heat treatment apparatus, when heat-treating the sheet-like fiber bundle, the blow nozzles are arranged at both ends, and the heating chamber has a simple structure. Since the heat treatment gas can be stably sprayed in parallel on both sides of the sheet-like fiber bundle that reciprocates a plurality of times, the quality of the sheet-like fiber bundle can be suppressed and the equipment cost can be reduced.

It is a sectional side view which shows typically the structure of the heat processing apparatus which is a typical Example of this invention. It is a top view which shows typically the structure of the heat processing apparatus, abbreviate | omitting the thread | yarn which drive | works a heat processing chamber. It is a top view which shows typically the heat processing chamber structure of the heat processing apparatus which installed the two suction parts adjacently which is a comparative example of this invention. It is a figure which shows typically the state which installed the control board in two places of the one end side and other end side of the heat processing chamber near a suction part as a preferable aspect of this invention. It is a top view which shows typically the measurement position of a present Example.

Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side sectional view schematically showing the structure of a heat treatment apparatus as a typical embodiment of the present invention. In the heat treatment apparatus 1 of the present embodiment, in the heat treatment chamber 2, heat treatment gas is blown in parallel from the blowing nozzle 3 onto both sides of the yarn 8 that reciprocates in the horizontal direction in the inside of the heat treatment chamber 2. It is a heat treatment apparatus that performs heat treatment continuously.

  FIG. 2 is a plan view schematically showing the structure of the heat treatment apparatus, omitting the yarn 8 running in the heat treatment chamber. As shown in the figure, on both sides of the heat treatment chamber 2, two circulation channels 7 and 7 ′ for circulating the heat treatment gas are provided, and a plurality of blowing nozzles 3 disposed at both ends of the heat treatment chamber 2, The heat treatment gas blown from 3 ′ flows in parallel across the yarn 8 that reciprocates a plurality of times, moves toward the center of the heat treatment chamber 2, and then opens to face the center of the heat treatment chamber 2. The air is guided to the circulation passages 7 and 7 'from the suction portions 4 and 4', heated to a desired temperature by the gas heating means 5 and 5 ', and the wind speed is controlled by the hot air blowing means 6 and 6', and then again. A plurality of blowing nozzles 3, 3 ′ are blown into the heat treatment chamber 2.

Next, based on FIG.1 and FIG.2, the heat processing apparatus of this invention is further demonstrated.
(Heat treatment equipment 1)
The heat treatment apparatus 1 includes a heat treatment chamber 2 having an entry / exit portion 10 for the yarn 8 at both ends, and two circulation channels 7 and 7 ′ for circulating a heat treatment gas inside and outside the heat treatment chamber 2. The heat treatment gas blown from both sides from each of the plurality of blowing nozzles 3 and 3 ′ disposed at both ends of the nozzle 2 flows in parallel along each yarn 8, and travels toward the center of the heat treatment chamber 2. Each yarn 8 is heated while moving. The heat treatment gas that has reached the central portion of the heat treatment chamber 2 is discharged out of the heat treatment chamber 2 through the suction portions 4 and 4 'that are open to face each other, and is guided to the circulation channels 7 and 7'. Then, the gas is heated to a desired temperature by the gas heating means 5 and 5 ′, and the air speed is controlled by the hot air blowing means 6 and 6 ′, and then blown again into the heat treatment chamber 2 from the plurality of blowing nozzles 3 and 3 ′. .
As described above, the heat treatment apparatus 1 includes the heat treatment chamber 2 and the two circulation channels 7 and 7 ′, and a heat treatment gas having a predetermined temperature and wind speed flows in the heat treatment chamber 2. ing.

(Running of the yarn 8 in the heat treatment chamber 2)
The yarn bundle 8 travels in the heat treatment chamber 2 by reciprocating a plurality of times in the horizontal direction. The yarn 8 forming this path is folded back by a predetermined set of guide rolls 9 disposed outside the heat treatment chamber 2, and enters the heat treatment chamber 2 through the entrances 10 and 10 ′ at both ends of the heat treatment chamber 2. Repeat sending and receiving multiple times. The number of turns of the yarn 8 is not particularly limited, and is appropriately designed depending on the scale of the heat treatment apparatus.

(Gas heating means 5 and hot air blowing means 6)
The gas heating means 5 used for this invention is not specifically limited, For example, well-known gas heating means, such as an electric heater, can be used. Also, the hot air blowing means 6 is not particularly limited as long as it has a desired function. For example, a known fan such as an axial fan may be used.

(Blowout nozzle 3, 3 ')
The plurality of blowing nozzles 3, 3 ′ of the present invention act to blow heat treatment gas in parallel from both sides to each yarn 8 from both ends of the heat treatment chamber 2 toward the center.
Specifically, the plurality of blowout nozzles 3 communicating with the circulation passage 7 of the first system are disposed on the upper side and the lower side of each of the traveling yarns 8 in the vicinity of the inlet / outlet portion 10 at one end of the heat treatment chamber 2. In addition, the plurality of blowout nozzles 3 ′ communicating with the circulation passage 7 ′ of the second system are arranged on the upper and lower sides of the traveling yarns 8 in the vicinity of the inlet / outlet portion 10 ′ at the other end of the heat treatment chamber 2. And arranged.

  In this way, in the present invention, the heat treatment gas is stabilized in parallel on the upper side and the lower side of each of the running yarns 8 from the blow nozzles 3 and 3 ′ toward both ends of the heat treatment chamber 2 toward the center. And can be sprayed.

  It is preferable that the speeds of the heat treatment gases blown from the blow nozzles 3 and 3 ′ arranged above and below the yarn 8 are the same. Further, it is preferable to minimize the variation in the flow velocity in the width direction and height direction of the hot air blown from the blow nozzles 3 and 3 ′, and the wind speed spot is preferably within ± 20% of the average wind speed. More preferably, it is within ± 10%.

(Suction part 4, 4 ')
In the present invention, two suction portions 4, 4 ′ communicating with the two circulation channels 7, 7 ′ are provided in the central wall of the heat treatment chamber 2 in the lateral direction or the vertical direction of the running yarn 8. An opening is provided so as to face directly. By disposing the suction portions 4 and 4 ′ in such a directly facing position, the traveling yarn 8 can be fired by giving the same wind speed and temperature history symmetrically in the lateral direction.

FIG. 3 is a plan view schematically showing the structure of the heat treatment chamber 2 of the heat treatment apparatus 1 in which two suction portions 4 and 4 ′ are installed adjacent to each other, which is a comparative example of the present invention. In the heat treatment apparatus 1 of this comparative example, the heat treatment gas flowing in the heat treatment chamber 2 in parallel with the yarn 8 from both ends of the heat treatment chamber 2 toward the center portion is in the center portion of the heat treatment chamber 2. The two suction portions 4, 4 ′ adjacent to the running direction of the strip 8 are guided to the circulation flow paths 7, 7 ′.
For this reason, the wind speed increases around the wall where the suction portions 4 and 4 'are opened, and the wind speed decreases as the wall approaches the wall. As a result, there is a possibility that firing spots are generated in the lateral direction of the yarn 8, smoke is generated in the yarn 8 in a region where the wind speed is lowered, or cutting is generated.

  Further, even when the suction portions 4 and 4 ′ are provided on the inner wall facing the central portion of the heat treatment chamber 2, the heat treatment gas is blown out when the suction portions 4 and 4 ′ are arranged so as not to face each other. The wind speed and direction of the heat treatment gas are disturbed in the central portion of the heat treatment chamber 2 such as flowing into the suction portions 4 and 4 ′ on the side close to the nozzles 3 and 3 ′. As a result, the yarn 8 may be smoked or cut.

  The distance between the center point of each of the suction portions 4 and 4 ′ and the midpoint of the line segment in the heat treatment chamber 2 extending in the direction in which the yarn 8 travels through the center point is determined by the yarn in the heat treatment chamber 2. 8 is preferably located within a range of 0.1 times the length in the traveling direction. When the suction portions 4, 4 ′ are arranged close to the position of one of the blowout nozzles 3, 3 ′, when the yarn 8 travels from the guide roll 9 to the downstream guide roll 9, the wind and direction However, the processing length becomes different, which leads to deterioration of the firing efficiency. It is more preferable that the distance between the center point of each of the suction portions 4 and 4 ′ and the midpoint of the line segment in the heat treatment chamber 2 passing through the center point and extending in the direction in which the yarn 8 travels is 0. preferable.

  When the same rectangular suction portions 4 and 4 ′ are opened on the central wall of the heat treatment chamber 2 so as to face the lateral direction of the running yarn 8, the height of each suction portion 4 and 4 ′ is increased. Is equal to the height of the heat treatment chamber 2, and the opening area of each suction part 4, 4 ′ is A, and B is the cross-sectional area of the surface perpendicular to the yarn 8 that runs in the heat treatment chamber 2. , A is preferably 0.5 to 1.0 times. If it is less than 0.5 times, the suction portions 4 and 4 'are narrow, the suction wind speed is increased, the vibration of the yarn 8 is promoted, and the single fibers in the yarn are rubbed together to generate fluff. This is not preferable because it causes a decrease. On the other hand, when the ratio is larger than 1.0, the wind speed increases in the area close to the suction portions 4 and 4 ′, but the area in which the wind speed decreases in the center area in the width direction is expanded. As a result, firing spots in the width direction may occur, smoke may occur in the yarn 8 in a region where the wind speed decreases, or cutting may occur, which is not preferable. More preferably, it is 0.7 to 1.0 times.

  It is preferable to install a perforated plate in the suction portions 4 and 4 'so as to flatten the wind speed distribution in the suction section. It is preferable to install a perforated plate in the suction portions 4 and 4 ′ because pressure loss is applied and the wind speed distribution around the suction portions 4 and 4 ′ can be further flattened compared to the case where no perforated plate is installed.

FIG. 4 is an example showing an aspect in which the control plate 11 is installed in two places on the one end side and the other end side of the heat treatment chamber 2 in the vicinity of the suction portions 4 and 4 ′. However, in order to show the control plate 11 in an easy-to-understand manner, the circulation channel 7 on the near side is excluded.
The control plate 11 has a plurality of openings through which the yarn 8 can pass, and the height of the openings increases toward the center.
By installing such a control plate 11, wind speed spots in the width direction of the yarn 8 can be suppressed. That is, in the vicinity of the suction portions 4 and 4 ', the wind speed tends to decrease at the central portion in the lateral direction of the yarn 8, but by setting the shape of the opening portion of the control plate 11 as described above, the heat treatment gas is formed in the central portion. A flow can be guided, and a decrease in wind speed at the center in the lateral direction of the yarn 8 can be prevented.

  In addition, by giving the control plate 11 a thickness and by processing the upper surface of the opening to be round in the thickness direction, the control plate 11 has a function of receiving the yarn 8, so that the yarn 8 has drooped due to cutting or the like. Even at that time, it is possible to prevent the yarn 8 traveling on the lower side from being entangled. Further, by processing the upper surface round in the thickness direction, even if the yarn 8 is rubbed, it becomes difficult to fluff.

  As described above, according to the heat treatment apparatus of the present invention and the flameproof fiber manufacturing method using the heat treatment apparatus, the blow nozzles are arranged at both ends when the yarn is heat treated, and the heating chamber has a simple structure. As the heat treatment gas can be stably sprayed from both sides in parallel to the yarn that reciprocates multiple times in the heat treatment chamber, the yarn can be kept from rubbing to improve quality and keep equipment costs low. be able to.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

FIG. 5 schematically shows the measurement position. FIG. 5 is a plan view schematically showing the structure of a heat treatment apparatus which is a typical embodiment of the present invention, as in FIG.
The width of the heat treatment chamber is 2200 mm, and the length in the width direction of the yarn 8 is also 2200 mm.
In FIG. 5, the positions on the yarn 8 are represented by combining the symbols A to C and 1 to 9 defined below.

  About the code | symbol (A-C) which shows the position of the horizontal direction of the yarn 8, the code | symbol A and B is provided to the point located 100 mm away from the both ends of the horizontal direction of the yarn 8, respectively, A symbol C is assigned to a point located at the center in the horizontal direction.

  Moreover, about the code | symbol (1-9) which shows the position of the running direction of the yarn 8, the running of the yarn 8 of the two suction parts 4, 4 'arrange | positioned so as to oppose the horizontal direction of the yarn 8 is carried out. A point 5 is assigned to a point aligned on a line aligned with the center position in the direction (hereinafter referred to as “center line”), and the point located on a line 500 mm away from this center line toward the blowing nozzle on the left side of FIG. 4 and further points 3, 2 and 1 are assigned to points located on a line 1000 mm to the left of this line. Further, reference numeral 6 denotes a point located on a line 500 mm away from the center line toward the outlet nozzle side on the right side in FIG. 5, and reference numerals 7 and 8 denote points located on a line 1000 mm away from the line to the right. , 9 is given.

In the following examples, the cross-sectional average wind speed blown from the blow-off nozzles at both ends was made uniform at 3 m / s, and the wind speed was measured at each position.
Note that the shapes of the two suction portions 4 and 4 ′ are the same rectangle, and the height (the vertical direction in FIG. 5) is equal to the height of the heat treatment chamber.

[Example 1]
The shape and arrangement of the suction parts 4, 4 ′ were as follows.
* Make the running yarn face both sides in the horizontal direction.
* The center point of each suction part and the midpoint of the line segment in the heat treatment chamber extending in the direction in which the yarn runs through this center point are matched.
* Make the height of the suction section equal to the height of the heat treatment chamber.
* When A is the cross-sectional area of the opening of each suction part and B is the cross-sectional area of the surface perpendicular to the yarn running in the heat treatment chamber, A = B × 0.25.
The results of measuring the wind speed from A1 to A9 are as shown in Table 1, and the highest wind speed was measured at A5 at the center of the frontage.

[Example 2]
From A1 as in Example 1 except that A = B × 0.5, where A is the cross-sectional area of the opening of each suction portion and B is the cross-sectional area of the surface orthogonal to the yarn running in the heat treatment chamber. The wind speed of A9 was measured.
The results of measuring the wind speed from A1 to A9 are as shown in Table 1. The wind speed values were slightly higher than the average wind speed from A4 to A6.

[Example 3]
From A1 as in Example 1 except that A = B × 1.0, where A is the cross-sectional area of the opening of each suction portion and B is the cross-sectional area of the surface orthogonal to the yarn traveling in the heat treatment chamber. The wind speed of A9 was measured. Moreover, the wind speed measurement of B1 to B9 was also implemented.
The results of measuring the wind speed from A1 to A9 are as shown in Table 1, and the wind speed value was almost the same as the cross-sectional average wind speed value of the blowout as a whole.

[Example 4]
From A1 as in Example 1 except that A = B × 1.5, where A is the cross-sectional area of the opening of each suction portion and B is the cross-sectional area of the surface orthogonal to the yarn running in the heat treatment chamber. The wind speed of A9 was measured.
The results of measuring the wind speed from A1 to A9 are as shown in Table 1. A low wind speed value was obtained from A3 to A5, and a higher wind speed value was measured from A7.

  In Example 1, since the cross-sectional area of the suction part is narrow, the latest suction wind speed becomes high. Moreover, in Example 4, since the suction part was long in the yarn longitudinal direction and was sucked in on the blowing nozzle side, the wind speed value was low in A3 to A5. If the frontage area of the suction part is optimized, it is preferably about 0.5 to 1.0 times the heat treatment chamber yarn width direction cross-sectional area.

[Comparative Example 1]
Implemented except that the arrangement of the suction portions 4 and 4 ′ is not opposed to each other, is shifted in the direction in which the yarn 8 travels, and the ends of the circulation channels 7 and 7 ′ are alternately arranged at the positions coincident with the center line. In the same manner as in Example 3, the wind speeds A1 to A9 were measured. Moreover, the wind speed measurement of B1 to B9 was also implemented, and each A, B wind speed average value was computed.
The result of the wind speed measurement is as shown in Table 2, which is less than the average cross-sectional wind speed of 3 m / s.

[Comparative Example 2]
The same measurement as in Comparative Example 1 was performed except that the suction portions 4 and 4 ′ were arranged adjacent to each other at the center line.
The results of wind speed measurement are as shown in Table 2, and the average wind speed on the A side far from the suction portion was low.

  In Example 3, the average wind speed is 3.1 m / s, whereas in Comparative Example 1, the area of the suction portion becomes longer by being arranged alternately, and the average wind speed is increased by being sucked on the outlet nozzle side. Decreased. Moreover, if the suction part is disposed adjacent to the one side wall surface, the wind speed decreases on the other wall surface side and the wind speed spots in the width direction deteriorate. From this result, it is preferable that the suction portion is arranged in a straight line.

[Example 5]
A perforated plate having a structure similar to that of Example 3 and having a porosity of 20% was installed on the cross section of the suction portion.
The results of wind speed measurement are as shown in Table 3, and the difference between the maximum and minimum wind speeds A1 to A9 was 0.8 m / s.
Table 3 shows the difference between the maximum and minimum wind speeds A1 to A9 in Example 3 and Example 5. As a result, it can be seen that the wind speed difference is smaller when the perforated plate is installed, and the wind speed distribution in the suction portion is smoothed.

[Example 6]
C1 to C9 wind speeds were measured with the same structure as in Example 3.
The results are as shown in Table 4, and the average wind speed was 2.5 m / s.

[Example 7]
In the structure of Example 3, a control plate was installed on the end surface of the suction part as shown in FIG.
The height of one control plate is 200 mm, and the center of the sheet-like fiber bundle width direction is the narrowest 50 mm. The control plate is installed so that the unevenness is reversed on each blowing nozzle side. Moreover, the height which a sheet-like fiber bundle passes is 50 mm.
The results of the wind speed measurement are as shown in Table 4, and the average wind speed from C1 to C9 was 3.3 m / s.

  From Example 6 and Example 7, the wind speed value at the center of the yarn width direction is set by installing a control plate in the suction portion that has an opening through which the yarn passes and the opening height increases toward the center in the width direction. Has increased. Larger notches in the control plate toward the center of the yarn width direction facilitate flow and contribute to an increase in wind speed.

1: Heat treatment apparatus 2: Heat treatment chamber 3, 3 ': Blowing nozzle 4, 4': Suction part 5, 5 ': Gas heating means 6, 6': Hot air blowing means 7, 7 ': Circulation flow path 8: Yarn 9: Guide roll 10, 10 ': Entrance / exit part (of the yarn) 11: Control plate

Claims (6)

In the heat treatment chamber, a heat treatment gas is sprayed in parallel from both sides to each yarn that reciprocates a plurality of times in the horizontal direction in the interior, and the yarn is continuously heat treated, and the yarns A heat treatment chamber having an entrance and exit, and two circulation channels for circulating the heat treatment gas inside and outside the heat treatment chamber,
The heat treatment chamber is provided with a plurality of blowing nozzles respectively communicating with the two circulation channels and two suction portions respectively communicating with the two circulation channels.
Among the plurality of blowing nozzles, the plurality of blowing nozzles communicating with the circulation passage of the first system are arranged on the upper side and the lower side of each traveling sheet-like fiber bundle in the vicinity of the inlet / outlet portion at one end of the heat treatment chamber. Arranged,
Among the plurality of blowing nozzles, the plurality of blowing nozzles communicating with the circulation flow path of the second system are the upper and lower sides of each traveling sheet-like fiber bundle in the vicinity of the inlet / outlet portion at the other end of the heat treatment chamber. The two suction portions are opened to face the lateral or vertical direction of the running yarn on the wall of the heat treatment chamber central portion,
The circulation flow path includes gas heating means and hot air blowing means, and is disposed outside the heat treatment chamber.
The heat processing apparatus characterized by the above-mentioned.   The distance between the center point of each of the suction portions and the midpoint of the line segment in the heat treatment chamber that extends through the center point in the direction in which the yarn travels is the direction in which the yarn in the heat treatment chamber travels The heat treatment apparatus according to claim 1, wherein the heat treatment apparatus is located within a range within 0.1 times the length. The two suction parts are the same rectangle, and are arranged so as to face the transverse direction of the running yarn, the height of each suction part is equal to the height of the heat treatment chamber, and the opening area of each suction part is A, The heat treatment apparatus according to claim 1 or 2, wherein A and B satisfy the following relational expression, where B is a cross-sectional area of a surface perpendicular to the yarn traveling in the heat treatment chamber.
0.5 × B ≦ A ≦ 1.0 × B   The heat processing apparatus in any one of Claims 1-3 with which the perforated panel is installed in the said suction part.   In the vicinity of the suction portion, there are a plurality of openings through which the yarn passes in two passages on one end side and the other end side of the heat treatment chamber, and the height of the openings increases toward the center portion. The heat processing apparatus in any one of Claims 1-4 which installed the control board made to suppress the wind speed spot of heat processing gas.   The manufacturing method of the flame resistant fiber which heat-processes a carbon fiber precursor fiber bundle using the heat processing apparatus in any one of Claims 1-5.

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