JPH0327125A - Fire-resisting device - Google Patents

Abstract

PURPOSE:To obtain fire-resistant fiber having excellent physical properties by feeding precursor fiber bundle to feeding side of burning furnace for heating treatment in treating gas atmosphere in specific state. CONSTITUTION:Precursor fiber bundle 3 is fed from inlet 27 and inert gas Q is blown from a gas-feeding nozzle 23 to replace to air in the fiber bundle. Then, the precursor fiber bundle 3 is reached at a treating room 7 through a sealing means 10; thus treating gas P is blown from the gas-feeding nozzle 23 and inert gas Q in the fiber bundle is replaced with the treating gas, then the fiber bundle is reached at a treating room 8 through a sealing means 11, thus the treating gas P and a slight inert gas Q are exhausted from an exhausting nozzle 24. By the above method, concentration of treating gas P component in a burning furnace 4 is kept constant.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a method for continuously feeding precursor fiber bundles, which are raw material fibers for flame-resistant fibers, to a firing furnace. The present invention relates to a flame-retardant device equipped with a gas replacement device for replacing gas with a processing gas, and particularly relates to a flame-retardant device suitable for the case where the firing furnace is flame-retardant in a processing gas atmosphere containing a toxic component such as a sulfur-containing gas. .

[Prior art] Flame-resistant fibers that exhibit excellent flame resistance and heat resistance for building materials, firefighting clothing, welding spark protection, etc. are usually polyacrylonitrile fibers, recycled cellulose fibers, and phenolic fibers. Fiber bundles (hereinafter referred to as 4 precursor fiber bundles) made of organic polymers such as fibers and pitch-based fibers are arranged in parallel and fed into a firing furnace equipped with a large number of rollers. It is manufactured by firing in air or an oxidizing gas atmosphere at a temperature of 200 to 300°C.

Carbon fibers are produced by further firing this flame-resistant fiber at a temperature of 800 to 2000°C in an inert gas atmosphere such as nitrogen or argon.
By performing graphitization at a temperature of 000° C. or higher, graphite fibers with even higher Young's modulus can be produced.

In recent years, such flame-resistant fibers have attracted attention as fibers to replace asbestos, but flame-resistant fibers have a non-uniform oxidation structure in which the degree of oxidation on the surface of the fiber is much greater than on the inside of the fiber. Therefore, the mechanical strength, especially the tensile strength, is low.
In addition, the toughness is low, and furthermore, it is difficult to spin or weave, and even if spinning or weaving is possible, the resulting product has poor abrasion resistance and heat resistance. There were many problems, such as its strength decreasing over time and loss of practical performance.

Therefore, in Japanese Patent Publication No. Sho 47-36461, the present applicant has developed acrylonitrile polymer fibers with 20% heat resistance in a sulfur dioxide atmosphere as a flame-resistant fiber that solves these problems.
We proposed a sulfur-containing flame-resistant fiber that becomes flame-resistant under temperature conditions of 0 to 500°C, and as an apparatus for industrially producing such a sulfur-containing flame-resistant fiber, we described the following in JP-A-62-276013. We proposed a flameproofing furnace (firing furnace) consisting of the following configurations.

That is, this flameproofing furnace includes a roller group for transporting the precursor fiber bundle, a chamber for forming a heated oxidizing gas atmosphere containing a toxic gas component surrounding the precursor fiber bundle,
A circulation system for exhausting the heated oxidizing gas to the outside of the chamber and supplying a part of the heated oxidizing gas to the chamber again via a heating device, and a supply hole for inert gas, and a part of the roller group or It is composed of a chamber for forming an inert gas atmosphere surrounding the entire fiber bundle, and the precursor fiber bundle is made flame resistant in an atmosphere containing toxic gas components, and part or all of this toxic gas component is removed from the precursor fiber bundle. This equipment continuously produces flame-resistant fibers by chemically bonding them into bundles.

[Problems to be Solved by the Invention] However, since the above-mentioned flameproofing furnace does not take into account the air in the precursor fiber bundle that is continuously fed,
During the flame-resistant treatment, the processing gas reacts with the oxygen in the air in the fiber bundle, causing yarn breakage and fluff due to heat generation. There was a problem in that only products with low levels of physical properties such as alkali resistance could be manufactured.

Therefore, as a result of intensive study on a device to solve these technical problems, the present inventor found that in order to obtain flame-resistant fibers with excellent physical properties, the following steps should be taken in the yarn feeding section of the precursor fiber bundle of the flame-proofing furnace: (i) The inside of the precursor fiber bundle is deoxidized, (ii
) The inside of the precursor fiber bundle is replaced with the processing gas, (iii) Air does not flow into the flameproofing furnace, (
iv) When using toxic gases, we discovered that it is important that the process gas containing the gas components does not leak out of the furnace, and as a result of further studies on flame-retardant equipment that satisfies these conditions, we have developed the present invention. It has come to this.

An object of the present invention is to solve the above-mentioned problems, and to easily replace the air in the precursor fiber bundle with a processing gas in advance when feeding the precursor fiber bundle to the firing furnace. The purpose of the present invention is to provide a flame-retardant device equipped with a gas replacement device with a high sealing effect that prevents air from flowing into the furnace from the furnace, thereby making it possible to continuously produce flame-resistant fibers of excellent quality. be.

[Means for Solving the Problems] A device for replacing gas in a precursor fiber bundle of the present invention that achieves the above object has the following configuration. That is, a firing furnace is provided for heat-treating continuously fed precursor fiber bundles in a processing gas atmosphere, and a firing furnace is provided on the yarn feeding side of the firing furnace to pre-inject the air in the precursor fiber bundles into the processing gas atmosphere. A flame-retardant device comprising: a gas replacement device for replacing gas with gas, the replacement device including a first processing chamber having an inert gas supply hole along the yarn feeding direction of the precursor fiber bundle; , a second treatment room I'I4 having an air supply hole for the treatment gas, and a third treatment room PI! having an exhaust hole for the treatment gas. The chambers are arranged in this order, and the first, second, and third processing chambers are connected to the phase q through a sealing means that surrounds the precursor fiber bundle. 3. Also, in the above-mentioned apparatus for replacing gas in the precursor fiber bundle,
The first, second, and third processing chambers are arranged in the order of the first processing chamber, the third processing chamber, and the second processing chamber along the yarn feeding direction of the precursor fiber bundle. This is a flame-retardant device characterized by the following:

Furthermore, in the above-mentioned device for replacing gas within the precursor fiber bundle,
The flameproofing device is characterized in that one of the two processing gas supply holes in the second processing chamber is used as a processing gas exhaust hole.

The precursor fiber bundle in this invention is polyacryloni 1
- Fiber bundles made of organic polymers such as rill fibers, regenerated cellulose fibers, phenolic fibers, and pitch fibers.

Further, the firing furnace may be either a known firing furnace or a flame-resistant furnace, and specifically, the flame-resistant furnace described as a conventional technique can be used.

In addition, this flameproofing furnace includes a yarn feeding section and a take-up section for the fibers to be treated, that is, a section 1-1 for the inflow and outflow of the fibers to be treated in the chamber.
Although there is no specific description of the 1 part seal, in the present invention, it is assumed that the following known sealing means is provided in the 11 parts.

The sealing means is a known sealing means such as a labyrinth, a slit, or a roller, and by surrounding the thread path of the precursor fiber bundle, the sealing means is used to seal the precursor fiber bundle in a contact or non-contact state. A means of sealing gas, processing gas, air, etc.

The inert gas refers to a known inert gas such as N2 or Ar gas.

The processing gas is, for example, air, 02, 03, No2, S0.
2.NOCI. ．． The present invention refers to known gases such as HCISCI2 and Cl2S2, and the present invention is suitable for cases where a processing gas containing toxic components is used. ,302,NOC
Processing gas containing components harmful to the human body, such as I, HCI, CI2, Cl282, etc.

[Example 1] Hereinafter, the content of the present invention will be described with reference to examples 1
, I will explain it in detail.

FIG. 1 is a schematic longitudinal sectional view of a flameproofing device 2a in which a firing furnace 4 and a gas replacement device 1 are connected.
The flame-retardant device 2a burns precursor fiber bundles 3, which are arranged in the width direction (direction perpendicular to 5 with respect to the paper surface of the figure) and which are supplied in the direction of the white arrow, in a processing gas 1). A firing furnace 4 for processing, and a gas replacement device 1 for replacing the air contained in the fiber bundle with a processing gas P before feeding the precursor fiber bundle 3 to the firing furnace 4. What does it consist of? Note that a sealing means 12.15 is provided at the entrance and exit of the firing furnace 4, and as shown in FIG.
When taking the fired fiber bundle 3 out of the furnace, the above-mentioned treatment PI contained in the fired precursor fiber bundle 3 should be prevented, such as preventing the fibers from entering the firing furnace. Preferably, a sealing device 5 is provided in order to further enhance the removal of gas F).

The firing furnace 1 is a furnace that heats the fiber bundle 3 to 200 to 300°C, and a heating means (not shown) for the fiber bundle 3 is installed inside or outside the furnace. The firing furnace may be a known firing furnace in which a large number of rollers (not shown) are provided in the furnace, and the fiber bundle 3 is wound in parallel around these rollers.

In order to prevent the leakage of the process gas P from inside the firing furnace 4 and the intrusion of air into the furnace, the gas replacement device 1 performs a first process in which the inert gas Q is shifted up and down through the air supply hole 21. chamber 6, a second processing chamber 7 having an air supply hole 21' for the processing gas P below -L, the mixing of the inert gas Q remaining in the fiber bundle 3 into the firing furnace 4, and the processing gas P A third processing chamber 8 having exhaust holes 22 above and below to prevent the leakage of the gas out of the furnace is arranged in this order on the yarn feeding side of the firing furnace 4, and these Sill means 10 and 11 are connected between the processing chambers 6, 7 and 8, respectively.

The first and second processing chambers 6 and 7 of the gas replacement device 1 have the same configuration, and each of the processing chambers 6 and 7 has the following structure.
An inlet 119 and an outlet 20 formed by separating rod-shaped yarn guides 19 on the left and right sides with a small gap ε that allows the precursor fiber bundle 3 to pass through, and inert gas It consists of an air supply hole 21 for Q, an air supply hole 21' for processing gas P, and an air supply nozzle 23 in which a plate with the rod-shaped thread guide fixed at its tip is arranged in a substantially "V" shape. Inert gas Q and processing gas P are introduced into the first and second processing chambers from the air supply hole 21'.
By supplying air, respectively, the inert gas Q or the processing gas P is injected from the air supply nozzle 23 over the entire width of the precursor fiber bundle 3 in a direction perpendicular to the fiber bundle. The third processing chamber 8 also has the same configuration as the first and second processing chambers 6 and 7, except that the third processing chamber 8
The point is that exhaust holes 22 for a mixed gas of processing gas P and inert gas Q are provided above and below.

In addition, in each processing chamber, the inert gas Q and the processing gas P are not necessarily simultaneously supplied and exhausted from above and below with the precursor fiber bundle 3 as a boundary, but may be supplied and exhausted from only one side.

Each of the sealing means 9 to 12 and 15 to 17 has a configuration in which the precursor fiber bundle 3 is surrounded by a labyrinth 25 in the form of a partition plate in a non-contact manner. Along the yarn feeding direction of the body fiber bundle 3,
Furthermore, they are fixed vertically with a gap ε' that is large enough for the precursor fiber bundle 3 to pass through. Note that the sealing means 9 of the gas replacement device 1 and the sealing means 17 of the sealing device 5
The above-mentioned thread guides 19 and 20 are fixed to the tip of the labyrinth 25 as an inlet 27 and an outlet 28 of the precursor fiber bundle 3, respectively. thread guide 19,
20 is preferably made of ceramic or metal, which has a small coefficient of friction; those made of metal are plated with a satin finish, and those made of ceramic are fired twice, for example, to enlarge the crystal grains on the surface. Preferably, the friction is reduced by coarsening the material. Although the labyrinth 25 depends on the thickness of the fiber bundle, the narrower the gap ε', the greater the sealing effect, and the labyrinth 25 is preferably 20 mm or less, and 10 m
It is more preferable to set it to m or less.

Further, it is preferable that the distal end of the labyrinth 25 is fixed to the housing 26 in a positional relationship such that the labyrinth 25 substantially faces each other as shown in the figure. Further, the gap ε between the air supply nozzle 23 and the exhaust nozzle 24 described above is preferably set to 20 mm or less in order to prevent gas flow as much as possible, and is preferably 5 mm or less.
The following is more preferable.
7. It is preferable that a sealing means 9 is provided on the yarn feeding side of the first processing chamber 6 as shown in the figure. The seal device 5 is provided to strengthen the seal, and the seal device 5 is provided to strengthen the seal.
5, and has processing gas P exhaust holes 22 above and below for exhausting processing gas P that has partially leaked from inside the firing furnace 4; A fifth processing chamber 14 having upper and lower air supply holes 21 for inert gas Q to prevent air from leaking to the atmosphere side and from entering the furnace is provided in this order on the yarn take-off side of the firing furnace 4. is,
A seal is installed on the yarn take-off side of the fourth and fifth processing chambers 13 and 14 and the fifth processing chamber 4 to prevent the flow of the processing gas P and inert gas Q. Means 16, 17 are connected.

In addition, the processing chambers constituting the sealing device 5 are replaced with the above-mentioned supply and exhaust nozzles 23 and 24 in the configuration of the first processing chamber 6 and the third processing chamber 8 of the double gas replacement device 1. The net-like filters 36 are provided in the first and third processing chambers 6 and 8, which are respectively referred to as the fifth and fourth processing chambers 14 and 13. It has the same configuration as the processing chambers 6 and 8.

The third processing chamber 8 of the gas replacement device 1 and the fourth processing chamber 13 of the sealing device 5 are connected to exhaust means (not shown) such as a vacuum pump or a Roots blower. Furthermore, if the displacement device 1 and the sealing device 5 described in FIG. 1 or described later in FIGS. 2 to 6 are structured so that they can be divided into upper and lower halves with the precursor fiber bundle 3 as the boundary, It is convenient because it is not only easy to thread the thread, but also easy to deal with when trouble occurs.In addition, the gas exchanger 1 and the seal neck 5 described above are both connected to the precursor fiber bundle 3. Although this is shown as a symmetrical configuration under L, of course,
It may also be asymmetrical.

Sealing stages 12, 1- provided in the firing furnace 4
5 and 17, in addition to the known sealing means, necessary ones can be selected from the first, third, fourth, and fifth processing chambers and used in combination as necessary.

The following is a description of the flameproofing device 2a in FIG.
Other embodiments of the gas replacement device 1 include the first and second embodiments in the figure.
, the third processing chambers may be connected in the following order along the yarn feeding direction of the fiber bundle 3.

FIG. 2 shows an embodiment of the present invention in which the processing chambers 6-8 shown in FIG. 1 are connected in the order of first processing chamber 6→third processing chamber 8-+second processing chamber 7. It is a schematic longitudinal cross-sectional view of the flameproofing device 2b. The only difference between this figure and the flameproofing device 2a in Figure 1 is that the second treatment chamber 7 and the third treatment chamber 8 have been replaced as described in -L (7). In other respects, it is the same as the one shown in Figure 1.

FIG. 3 shows that the second processing chamber 7 having the processing gas supply hole 21- shown in FIG. [7] This is a schematic vertical cross-sectional view of a flame-retardant device 2c of the present invention to which a gas replacement device is connected. The difference between this figure and the flame-retardant device 2a of FIG. 1 is that the second processing chamber 7 The lower processing gas P supply hole 21-' is changed to the processing gas P exhaust hole 39 in 1,
This point is the second processing chamber 38, and the other points are L.
1 is similar to that in FIG.

Next, FIGS. 4 to 6 are views showing embodiments of the sealing means other than the labyrinth type described in 7 above, and FIG. 5 and 6, which are schematic cross-sectional views of the cellular sealing means in which cells 29 shaped like 1 and 29 are arranged along the running direction of the precursor fiber bundle 3, FIG. 5 is a schematic perspective view of a slit type sealing means, and FIG. 6 is a schematic vertical sectional view of an n-type sealing means.

The sealing means shown in FIG. 4 seals the honeycomb-shaped cells 29 made of the partition material 30 along the running direction of the fiber bundle 3 of the housing 26 so that the open ends of the cells are in contact with the fiber bundle (7) so that there is no gap. 31 is a yarn guide for avoiding troubles such as yarn breakage and fuzz generation caused by the fiber bundle 3 coming into contact with the open end of the cell 29. In the running direction and direct flight direction of 3,
Further, it is bonded to the housing 26 with a heat-resistant adhesive at a position slightly higher than the open end of the cell 29. In this embodiment, the shape of the cell 29 is a hexagonal shape as shown in FIG. 4, a so-called honeycomb shape made of commercially available stainless steel, aluminum, vinyl chloride, etc.;
It can be made into a lattice shape, polygonal shape, etc. By fixing the open ends of the cells 29 in a positional relationship such that the open ends substantially face each other like the labyrinth 25 described above, the sealing effect can be further enhanced.
The slit-type sealing means shown in the figure has slits 1 and 33 set on the joining surface of the housing 32, which is divided into two parts, so that the entire width of the precursor fiber bundle 3 is slightly larger than the thickness of the entire fiber east. The inner surfaces of the slits 1 and 33 are coated with ceramics or matte plating having a small coefficient of friction.

The sealing means of the eyelet type shown in FIG.
4 is connected to the upper part' through the fiber bundle 3 within the housing 35. This mouth ring 34 rotates by active drive or contact resistance with the fiber bundle 3, and in order to prevent damage to the fiber bundle 3 and improve the sealing effect, a material with a smooth surface and high flexibility is selected. It is preferable to do so. Specific materials include, for example, baking a silicone sponge made of a single foam of silicone onto a metal shaft.
Furthermore, it is preferable that the outer layer is coated with silicone rubber having low hardness, and then machined to give a smooth cylindrical surface. Further, the housing 35 has a structure that can be divided into upper and lower halves, and by making one of the housings fixed and the other housing movable, the gap between the rolls can be adjusted as desired.

In addition, in the gas replacement device 1 of the present invention, in particular, as the processing gas P, sulfur dioxide, nitrosyl chloride, hydrochloric acid, chlorine,
When using an oxidizing toxic gas containing sulfa chloride or the like, steel materials generate sulfide scale due to so-called hot gas corrosion.

Therefore, among the gas replacement device 1 and the sealing device 5 described above, the materials of the members that come into contact with the processing gas P may be, for example, inorganic materials such as glass or ceramics, materials with linings or coatings applied to the surfaces of these materials, or metals. As for the material, it is preferable to use a corrosion-resistant material made of a Cr-containing alloy such as SUS304 or SUS316.

[Function] Next, the function of the flameproofing device of the present invention will be explained with reference to FIG.

First, the first processing chamber 6 and the sealing device 5 of the gas replacement device 1
An inert gas Q is supplied from the air supply hole 21 to the fifth processing chamber 14 of the firing furnace 4 and the second processing chamber 7 of the gas replacement device 1 by an air supply means (not shown). 37, 21'
The gas pressure is several tens of mmH20 to several 1 relative to atmospheric pressure.
0 0mmH2 0 High processing gas P is supplied. Next, the exhaust means (not shown) is operated, and the third
In the processing chamber 8, the processing gas P flowing in from the seal stage 11
1 and sealing means 10 and 11, while in the fourth processing chamber 13 of the sealing device 5, the processing gas P flowing in from the sealing means 15 is removed.
1 and the inert gas Q flowing in from the sealing means 16.

For the flameproofing device 2a prepared in this way, the population is 2
When the precursor fiber bundle 3 is fed from the gas exchange device 1
In the first processing chamber 6, an inert gas Q is blown from the air supply nozzle 23 over the entire width of the precursor fiber bundle 3 in a direction perpendicular to the fiber bundle, and the air inside the fiber bundle is blown by the inert gas Q.
will be replaced with At this time, a part of the inert gas Q leaks out of the furnace through the sealing means 9, so that air is prevented from entering the furnace from the inlet 27, and the processing gas P leaking from the sealing means 10 is prevented. Leakage outside the furnace is prevented.

Next, when the precursor fiber bundle 3 reaches the second processing chamber 7, the processing gas P is blown from the air supply nozzle 23 over the entire width of the fiber bundle 3 in a direction perpendicular to the fiber bundle. The inert gas Q in the fiber bundle supplied in the first processing chamber 6 is replaced with the processing gas P, and is completely deoxidized. Next, when the fiber bundle 3 reaches the third processing chamber 8, the processing gas P flowing in through the sealing means 11, a small amount of processing gas P flowing in from the firing furnace 4 via the sealing means 12, and the sealing means 10, 1
Since the small amount of inert gas Q that has flowed in through the firing furnace 4 is exhausted at the same time, the processing gas P from the firing furnace 4 can leak out of the furnace.
In addition, the inert gas Q is completely prevented from entering the furnace, and the concentration of the processing gas P component in the firing furnace is maintained constant. Therefore, only the fiber bundle in which the air in the fiber bundle 3 has been completely replaced with the processing gas P is fed to the firing furnace 4.

Then, in the firing furnace 4, the processing gas P is passed through the air supply hole 37.
is supplied, a predetermined firing process is performed to produce flame-resistant fibers 3', and the fibers 3' are taken outside via the sealing device 5. As in the case of the gas exchange device 1, the fourth processing chamber 1
3, the processing gas P is exhausted, preventing the processing gas P from leaking out of the firing furnace 4, and at the same time preventing the inert gas Q from entering the furnace from the fifth processing chamber 14. thwarted. Further, in the fifth processing chamber 14, the processing gas P in the flame-resistant fiber 3 is completely replaced with the inert gas Q, and the processing gas P is prevented from leaking out of the furnace and from outside the furnace to the firing furnace 4. air infiltration is prevented.

In this way, the precursor fiber bundle 3 in which the air in the fiber bundle 3 has been completely replaced with the processing gas P is supplied to the firing furnace 4, and the processing gas P is replaced by the gas replacement device 1 and the sealing device 5.
This prevents air from leaking out of the furnace and from entering the furnace, and also prevents air from leaking out of the furnace and preventing air from entering the furnace. The sealed seal means prevents gas flow due to the pressure loss that occurs at each labyrinth.
This will further promote the above effects.

? In addition, when the configuration of the flame-retardant neck is as described above, the flame-retardant device 2l-) of the embodiment shown in FIG.
Compared to 1-1 threshold flameproofing device ■2a, the supply location of Therefore, the effect that leakage of the process gas l) to the outside of the furnace is less likely to occur is achieved.

In addition, when the configuration of the flameproofing device is the flameproofing device 2c of the embodiment shown in FIG.
8, the processing gas 1) containing toxic components is supplied E5 and then exhausted, so that the processing gas 1] is applied to the fiber bundle 3 by 1-. Since the f4 is blown as if penetrating, the first -
Compared to the flameproofing device 2a shown in the figure, the present invention has the effect that the efficiency of replacing the inert gas and residual air in the fiber bundle with the processing gas is high.

In any of the flameproofing devices mentioned above, the supply of inert gas Q: :tt is to prevent air from entering the furnace and processing gas P from flowing out of the furnace. Supply air pressure to atmospheric JY {several 10mmH2 o to several 100m
It is preferable to set m 1N 2 0 high, and
The supply power of the processing gas 1) is preferably about the same as the processing gas P concentration in the firing furnace in order to completely replace the trapped air in the precursor fiber bundle 3 with the processing gas P'. It's better than 2, but it's definitely 1.
It is not necessary that the concentration of the purifying gas in the firing furnace be the same, and in order to increase the substitution efficiency into the fiber bundle, the concentration may be higher than that in the firing furnace. Further, the processing gas F) exhausted from the second} and fourth processing chambers 8 and 1-3 may be supplied to the second processing chamber 7 again and reused by the I/C.

Flameproofing device 2a according to the present invention configured as shown in FIG.
Then, 50=6 of N2 gas and 1;02 gas were supplied from the first and fifth processing chambers 6, 14, etc.
00l/min, 10-2oool/min, and on the other hand, from the third J and fourth processing chambers 8 and 13, exhaust air is connected to the respective processing chambers. By operating the stages, the pressure inside the firing furnace 4 is increased to 40-
Maintain the temperature at 500mmH20 and the temperature inside the furnace at 200-
After setting the temperature to 300°C, change the precursor fiber resistance East 3 from input IN27 to 0.5 and continuously feed the yarn at a yarn feeding speed of 30 m/min.
2. And people t-. The leakage state of the treated gas P from +27 and the output '-128 and the physical properties of the obtained flame-resistant fiber 3' were evaluated.

The obtained flame-resistant fiber 3' is satisfactory in both sulfur content and strength, and during the operation of the flame-resistant neck 2; Man[
There is no leakage from 127 and 028, and there is no occurrence of yarn breakage, L feathers, or leakage from the fiber bundle. 1. Rubble due to condensation of thermal decomposition products was also not observed.

In addition, the labyrinth type seal was replaced with a sealing means of a different type, that is, a honeycomb type, a slit type, or a roll type. Favorable labyrinth type seals were obtained.

1-Effects of the Invention] As explained above, the flame-retardant device according to the present invention according to claim (1) has a structure in which the flame-retardant device according to the present invention according to claim (1) is provided on the yarn feeding side of the firing furnace along the yarn feeding direction of the precursor fiber bundle. 1) with an inert gas supply hole;
In the processing chamber, the processing gas supply hole is shifted by 9-i.
1! The chamber and a third processing chamber with processing gas exhaust holes (N-4) are connected in this order, and the first and second processing chambers are connected in this order.
, each of the third processing chambers and the firing furnace were connected via sealing means (1-2) surrounding the +ffii precursor fiber bundle (1-7) with a gas exchange head (1-7) connected to each other. The precursor fiber bundle is fired in a firing furnace.
When feeding the yarn, the air contained in the precursor fiber bundle is first replaced with an inert gas, and then replaced with a processing gas.The interior of the precursor fiber bundle is completely deoxidized. Yarn can be fed at 12. Even if the processing gas in the firing furnace is a sulfur-containing gas such as sulfur oxide 74, the gas replacement device described in
- and a third processing chamber having a processing gas exhaust hole are installed through sealing means, so that air entering the furnace body from the yarn feeding side of the firing furnace and toxic This has the excellent effect of completely preventing the processing gas containing components from leaking out of the furnace.

In addition, the irj4 flame oxidation installation according to the present invention as set forth in claim (2) can be performed by replacing the second and third processing chambers of the flame resistant device according to claim (1), thereby reducing the supply of processing gas I). Compared to the flame-retardant device of claim (1), the gas can be supplied to a position closer to the inside of the device, and can be exhausted at a position closer to the outside of the furnace than the supply position. This has the effect of preventing leakage.

Furthermore, in the flameproofing device according to the present invention as set forth in claim (3), in the flameproofing device of claim (1), a sixth chamber is provided in which the processing gas P is supplied and then exhausted instead of the second processing chamber. By providing the treatment chamber, the treatment gas P is blown to penetrate the fiber bundle, so the efficiency of replacing the air in the fiber bundle with the treatment gas is improved compared to the flameproofing device of claim (1). It has an excellent effect of being high.

Therefore, in the firing furnace, processing can be stably performed under desired processing conditions, and high-quality flame-resistant fibers can be stably produced.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional view of a flame resistant device according to the present invention, and FIGS. 2 and 3 are schematic longitudinal sectional views of a flame resistant device according to the present invention in a different embodiment from the flame resistant device shown in FIG. It is a front view. 4 to 6 are diagrams showing sealing means of a different embodiment from the sealing means used in the flameproofing device shown in FIGS. 1 to 3, and each is a schematic cross-sectional view of a honeycomb type sealing means. FIG. 1 is a schematic perspective view of a slit-type sealing means, and a schematic longitudinal cross-sectional view of a roll-type sealing means. Explanation of symbols in the drawings 1: Gas replacement device 2 aN 2 b) 2 C in the precursor fiber bundle: Flame resistant device 3: Precursor fiber bundle 3': Flame resistant fiber bundle 4: Firing furnace 5: Sealing device 6: First processing chamber 7: Second processing chamber 8: Third processing chamber 9-12: Sealing means 13: Fourth processing chamber 14: Fifth processing chamber 15-17: Sealing means 21, 21'2 Air supply holes 22, 39: Exhaust hole 27: Population 28: Outlet 38: 2' processing chamber P: Processing gas Q: Inert gas

Claims (3)

[Claims] (1) A firing furnace for heat-treating continuously fed precursor fiber bundles in a processing gas atmosphere; and a firing furnace provided on the yarn feeding side of the firing furnace to pre-treat the air in the precursor fiber bundles. A flame-retardant device comprising a gas replacement device for replacing gas with gas, the replacement device including a first processing chamber having an inert gas supply hole along the yarn feeding direction of the precursor fiber bundle. A second processing chamber having an air supply hole for the processing gas, and a third processing chamber having an exhaust hole for the processing gas are arranged in this order, and each of the first, second, and third processing chambers are arranged in this order. A flame-retardant device characterized in that the processing chambers are interconnected through a sealing means surrounding the precursor fiber bundle. (2) In the gas replacement device according to claim (1), the first
, the arrangement order of each of the second and third processing chambers is as follows along the yarn feeding direction of the precursor fiber bundle: the first processing chamber, the third processing chamber,
A flame-retardant device characterized in that the second processing chamber is connected in this order. (3) A flame resistant device according to claim 1, wherein the second processing chamber having the processing gas supply hole is provided with a processing gas exhaust hole.