DE2231731A1 - METHOD AND DEVICE FOR PRODUCING CARBON FIBERS - Google Patents

Description

Patent attorney

Dr. J. Steffens ²⁸

8032 Lochham / Ii / Ichn., Mozarttfr. M Quira-2

Tel. (0811) 872551

Quimco GmbH, Hegibachstrasse 74, GH-8O32 Zurich, Switzerland

Method and device for the production of

Carbon fiber ..

The invention relates to the production of carbon fibers, in particular an apparatus and a method for partial oxidation and subsequent carbonization an endless ribbon or bundle of fibers, the molecular chains of which contain predominantly carbon atoms.

Processes are known in which a considerable number of carbon-containing precursors, in particular highly oriented synthetic polymers, for example polyacrylonitrile, can be used for the production of carbon fibers. These methods in particular consist of two stages, namely (a) the oxidation under controlled conditions, generally with air, at a relatively low temperature (for example 22O ⁰ C), an exothermic reaction occurs whose chemical composition has not been fully elucidated, and ( b) carbonization at high temperature (usually

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at 150 O or even above) in an inert atmosphere, whereby an endothermic reaction takes place through which the intermediate product formed in step (a) is converted to graphite.

Such prior art methods can be relatively easily performed on a laboratory scale or perform semi-industrial scale, with suitable modifications of conventional textile processing devices and methods are used for the pre-charring stages and wherein charring even then is carried out discontinuously. However, it has proven extremely difficult to transfer these devices or mode of operation to a large-scale process, in particular to a fully continuous process for the production of • endless carbon fibers. These difficulties are major can be attributed to process step (a) mentioned at the beginning, since it is a uniform and precisely regulated one Action by an oxidizing gas on a very large surface of the preliminary product, which is in the form of strands, knitted fabrics, fleeces, etc., is necessary. There is also the risk that by a mutual surface covering of the fibers by closely neighboring fibers, a non-uniform one Reaction takes place. Furthermore, the poisonous gases inside the device can be seen in continuous passage of a sliver or slivers of fiber does not hold back and it does not prevent a serious one The temperature control is impaired as a result of the exothermic course of the reaction. Difficulties also result from the fact that in step (b) the high-temperature reactor, through which a large amount of fiber is freely and continuously

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must be shielded against the ingress of oxygen must and differences in optimal speeds exist in the individual procedural stages, so that storage devices that effect compensation must be provided within the course of the procedure.

According to the British Patent Specification 1,168,619 there is provided indeed already drive and tension devices (e.g., drum or roller sets) within the Oxydationsofens in which the above-mentioned step (a) of the process is carried out, but DER · art arranged drive and tensioning devices occupy an inappropriately high proportion of the volume of the furnace and thus make this type of device unsuitable for the industrial scale in terms of its dimensions and the costs involved. The mercury sealing devices described in this British patent specification 1,168,619 against the entry of reactive gases, in particular oxygen, into the carbonization furnace are also very disadvantageous because they are extremely expensive and pose a high toxic risk. For these reasons, they are completely unsuitable for the industrial scale.

According to the invention an apparatus for the continuous production of carbon fibers from fibrous Intermediate products, the molecular chains of which are predominantly carbon Atoms contain, made available, which is characterized in that (1) the drive and voltage devices for the fibers arranged entirely outside the oxidation and carbonization ovens are, and (2) the sealing devices are such as those in the simultaneously filed German Patent application (according to the British

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_ 4 see patent application 30 254/71) are described.

Used to carry out the method according to the invention an elongated oxidation furnace and an elongated carbonization furnace and a device for leading through an endless belt or endless belts consisting of lines with a predominant The content of carbon atoms in the molecule is made through the oxidation furnace and the carbonization furnace. The flat fiber ribbons, which can be about 2 mm thick, are produced, for example, by one next to each other in a horizontal plane endless lengths of fibers from yarn packs through one in the textile industry usual slip-on gate leads. An example of this are 24 commercially available textile yarns, each 520 000 single threads contained and leading to an end bandwidth 1.8 m can be processed, which enables easy control and handling. The belt is continuously driven from the slip-on creel by a controlled speed Multiple roller device through and inserted into the oxidation furnace. A corresponding set of regulated with Speed driven rollers are provided at the outlet from the oxidation furnace so that A set tension or relaxation will be applied to the sliver as it exits the oven can. The furnace is provided at each end with a sealing device of the type described, which has a slot or a narrow rectangular opening through which, on the one hand, a sliver into the Oven can get, which, however, on the other hand, essentially seals the inlet and outlet ends of the oven. A blower and a pipe system or equivalent devices are provided for a stream of a

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oxidizing. To introduce gas in the Oxyd at ions furnace and circulating the gas through the sliver as it passes through the oven.

The casing enclosing the chamber of the oxidation furnace (hereinafter referred to as the ^{oxidation chamber "11} ") may consist of one or more parts; in the latter, the various parts are all assembled to form a chamber of any desired length by choosing the correct number of Along the path through the oxidation furnace intended for the fiber band, rods for guiding the band can be provided.

Most expediently, the ribbon-shaped fiber mat consists of oriented fibers.

According to one embodiment of the invention, the Oxidation chamber in one of the fiber support devices containing upper space and a lower space containing gas heating devices. It Means are provided to allow the oxidizing gas to pass through the oxidizing chamber enters an inlet point at or near the end of the furnace, then flows along the lower part of the oxidation chamber where it is heated by gas heating means and then flows into the upper part of the oxidation chamber and returns along this, where it flows through the fibers. Most of the gas is most conveniently recycled. Fresh oxidizing gas is introduced through the inlet point to keep an oxidizing atmosphere in the

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Chamber is maintained.

The deflection devices are therefore provided to to direct the gas several times with each complete cycle through the sliver, so that all the fibers in the Sliver are oxidized substantially uniformly.

According to a modified embodiment of the invention runs a plurality of parallel channels in the longitudinal direction through the oxidation chamber, wherein a separate fiber bundle can be passed through each channel. Each of these channels points at the bottom Holes through which the oxidizing gas is passed.

One or more fans are preferably used to generate the gas flow. The gas can through a heat ■ exchanger or an electrical heater. Near "the slit-shaped openings are sealing devices connected in series according to the German patent application filed at the same time (according to the British

Patent application 30 254/71) described type, provided which, on the one hand, the passage of the sliver or the slivers and any knots or reinforcements they may contain, on the other hand, however, prevent the passage of gas. In the spaces between the sealing devices a higher gas pressure than atmospheric pressure can be maintained to support their operation.

The knots or reinforcements produced in the sliver are arranged in the longitudinal direction at a distance from each other, so that the sealing devices connected in series are not simultaneously due to the passage the knot will be pushed open.

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The carbonization furnace used according to the invention for the production of the carbon fibers has a longitudinal Iiehe Oven Chamber (hereinafter referred to as "Garbonization Chamber" with a small cross-section and an opening at each end. With this construction, the for the necessary high-temperature heating elements necessary flat zones surrounding the carbonization chamber are created. Means are provided for creating a temperature gradient along the chamber. Further Rollers are provided that move the endless slivers through the carbonization sliver in the direction of the rising Pass temperature through. .

There is also a device to ask about the sliver when it passes through the carbonization chamber and means for maintaining a non-oxidizing atmosphere within this chamber intended.

In addition, a device for the gas supply into the carbonization chamber and a device are preferred available for the gas discharge from the carbonization chamber. In addition, the openings are on the Ends of the carbonization chamber preferably with in Series-connected sealing devices, which allow the passage of the sliver, but prevent a substantial loss of gas from the carbonization chamber takes place.

The device for pulling the slivers through the device most expediently comprises drive rollers, the speed of which is regulated and which is located outside the deo oxidation and boning oven. The drive rollers are driven at such speeds that the sliver

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desired Spannimg can be imposed.

The device for generating a temperature gradient in the Oarbonisierungskamiüer preferably consists of along this chamber spaced heating elements,

A preferred embodiment of a carbonizing furnace v / eist a rectangular cross-section elongated in the horizontal direction. The establishment to carry the "fibers comprises a plurality of horizontal guide rods, which are preferably made of graphite and perpendicular to the longitudinal axis of the carbonization furnace ens are arranged.

The sealing devices at each end of the carbonization furnace represent series-connected pneumatic devices as they are in the concurrently filed German patent application ...... (corresponding to British patent application 30 254/71) are described, the space between the series-connected closures with an inert gas, e.g. nitrogen, "at a pressure higher than atmospheric pressure and a higher pressure than in the carbonization oven. In a preferred embodiment of the garbonizing oven is the upper part removable.

The invention relates to an oxidation furnace and a garboning furnace of the aforementioned type in combination with a collecting device for collecting the carbon fibers emerging from the carbonization furnace.

Between the oxidation furnace and the carbonization furnace there is a storage device that holds it during

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■ - 9 -

limited times enables the oxidized sliver in order to enable compensation for different processing speeds in the two ovens, without having to cut the sliver and put it back together again.

The storage device can consist of a carriage mounted under the oxidation furnace b:; w. Carts exist that in one direction to store the fibers and in the opposite direction to release the stored ones Fibers can be moved.

All elements of the device are designed to be tied at roughly knotted knots in the slivers of fiber can adapt and are suitable for continuous uninterrupted operation.

The oxidation furnace and the carbonization furnace can with facilities (e.g. washing towers) for cleaning the gas drawn off from the two ovens or be equipped or combined with devices for burning the gas.

In the drawing:

1 shows a schematic representation of an embodiment of the device according to the invention;

Fig. 2 is a fragmentary longitudinal section of an embodiment of an oxidizing furnace having a Represents part of the device according to the invention;

Figure 3 is a fragmentary schematic cross-section through the furnace shown in Figure 2;

Figure 4 is a schematic end view of the embodiment of Figure 3;

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- ίο -

Pig. Fig. 5 is a fragmentary longitudinal section of a guide shape by the carbonization furnace according to the invention;

6 shows a graph of the temperature gradient in the carbonation chamber of in Fig. 5 ovenc shown;

7 is a graph of the temperature gradient en in the cooling section of the carbonization furnace;

Figure 8 is a side view of the embodiment shown in Figure 5; and

FIG. 9 is a plan view of the embodiment shown in FIG. 8.

Fig. 1 shows an oxidation furnace which has an elongate oxidation chamber 40 with a rectangular cross-section. The oxidation chamber 40 is shown schematically in longitudinal section in FIG. The other half of the furnace is essentially a mirror image of the half shown. The oxidation chamber is divided by a partition wall 43 into an upper chamber space 41 and a lower chamber space 42. The partition 43 is interrupted at the midpoint of its length in order to leave out a gap or gap 44 through which gas can flow from the lower chamber space 42 into the upper chamber space 41.

Two sealing devices 100 (see Fig. 1) are located before the inlet to the oxidation chamber 40. An between the sealing devices and the oxidation chamber slot-like passage piece 45 (see Fig. 2) has such a sufficient length that the sealing

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devices arranged at a certain distance in front of the furnace thereby preventing the heat in the oven from damaging the sealing device 100. A continuous fiber band 46 (Pig. 2) or several such bands can pass through the upper chamber space 41 of the furnace are running.

A tube 47 (Mg. 4) at the end of the oxidizing furnace provides an inlet for an oxidizing gas into the lower one Chamber space 42, so that the oxidizing gas along this Room can flow until it reaches the middle of the furnace «There the oxidizing gas flows through the In the partition 43 located gap 44 in the upper chamber space 41 of the furnace. The oxidizing gas is through electric heating elements (heating bands) 48 (Pig * 2) heated, which are arranged in the lower chamber space 42 of the furnace and extend across the width of the oven.

The oxidizing gas is released by fans 49 (Pig * 2) along the upper chamber space 41 of the furnace to the ends of the oven is sucked back and leaves the oven at each End via lines 50. The fans 49 generate a sub-atmospheric pressure and thus reduce it there is a substantial risk that the gas will escape from the ends of the Oven through the sealing devices.

The fans cause a return of the oxidizing gas through the pipes 47. All during Liquid or solid substances resulting from the process are caught in the cold traps 51 (Pig. 4). The polluted air is withdrawn through tubes 52 (Pig. 4). The polluted air and the impurities are transferred to an incinerator.

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Fresh air can via additional tubes 52 a (Fig. 2) as well - as a result of penetration through the sealing device are fed.

The oxidation furnace is made of prefabricated screwed together Sections built so that you can adjust the length of the oven to your choice. The roof of the furnace can be detachable in parts in order to allow the sliver or slivers to be drawn in initially to enable «The oxidation oven is heat insulated.

The oxidation furnace is also available with a variety of Guide rods 53 made of polished corrosion-resistant Steel, which are mounted on V-shaped brackets 54 to support the sliver, which is alternately guided under and over the bars 53. On each side of each guide rod 53 are two deflection devices 55 assembled from polished corrosion-resistant steel, the construction of which is passing by of knots in the sliver or slivers allowed, but the passage of oxidizing gas along the oxidation chamber - except through the fibers - prevented. Alternating management staff 53 are attached to the roof of the furnace or to the partition wall, as are alternating pairs of deflectors 55 ·

The deflectors 55 extend over the full width of the oxidation furnace. The stream of the oxidizing Gas runs essentially in the schematic by the arrows in Flg. 2 displayed V / eise. So that becomes oxidizing gas causes it to pass several times at slow speed through the sliver or slivers to flow through the furnace as it passes.

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This system is designed in such a way that, on the one hand, the flow rate of the oxidizing gas through the sliver or slivers is sufficient to increase the heat generated by the exothermic reaction and on the other hand enough oxidizing gas to oxidize the innermost fibers of the tape stands. The system therefore prevents the oxidizing gas from flowing through the fibers at high speed, which creates high pressure drops and requires the use of an extremely high fan output will be. At the same time, the system ensures a high flow rate of the oxidizing Gas in the longitudinal direction, which is used to produce uniform temperatures across the length of the furnace as well is necessary for easy temperature control.

The gas flow velocity along the oxidation furnace can be in the range from 7.5 to 12.5 m / sec, while the speed through the belt or belts can be 0.15 to 0.6 m / sec. The gas velocity through the belt or belts is less than the corresponding speed along the Oven, since the flow through the belt or belts with each passage over substantially the entire Surface of the tape lying between two guide rods takes place.

The smooth design of the guide rods 53 and the deflection devices 55 contributes to breaking the individual threads in the sliver or slivers during the passage through the oxidation furnace impede".

The oxidation furnace is attached to its center and mounted on support devices that have an exterior

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elongation and contraction in the longitudinal direction. equip. With this mounting system, the use Avoided expansion links in the furnace housing and enables the formation of a smooth inner oven profile.

One embodiment of a carbonization furnace is shown in FIG Pig. 5 shown. A housing encloses an elongated rectangular garbonization chamber 56 which is shown in FIG an upper chamber space 57 "and a lower chamber space 58 is divided. Each end of the garbonization chamber 56 has an elongated slot-like opening so that the slivers 59 can pass through the upper chamber space 57. Connected in series double sealing devices 60 and 61, hereinafter are attached to each end of the carbonization furnace. Between Sealing devices at the outlet end and the rectangular part of the furnace is a cone-shaped one Cooling section 69.

Electric heating elements 62 made of graphite yarn are shown in FIG an inert atmosphere in "the lower chamber space 58 of the carbonizing furnace in order to avoid the in Pig. 6 to generate temperature gradients shown. In this Pigur is the percentage of length on the abscissa of the rectangular part of the carbonization furnace and on the ordinate the temperature (in C) of the carbonization furnace applied.

The cooling section 69 serves to cool the fibers a temperature below 100 ° 0, the heat being given off to the atmosphere. The temperature gradient inside the cooling section 69 is in Pig. 7 shown

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represents the length (in mm) on the abscissa and the temperature (in ⁰ G) on the ordinate.

A nitrogen atmosphere is created in the carbonization furnace maintained with the gas flowing into the furnace through tubes 63 (Fig. 9) at the inlet and outlet ends and from the furnace through the tube 67 located in its center zμsamπlen with the products of Carbonization reaction, such as hydrogen cyanide, withdraws. The gases are passed through a cold trap. And then washed or burned ..

The space 65 between the series-connected sealing devices 60 and 61 is filled with nitrogen at a pressure higher than atmospheric pressure and than flushed the pressure in the carbonization furnace. The nitrogen becomes in the space between the inlet sealing devices fed in via the pipe 64 and withdrawn from this space via the pipe 66 (Pig. 9). The gas withdrawn from the pipe 66 is either scrubbed or burned in the incinerator. The space between the Outlet sealing device is only equipped with an inlet pipe 64.

The sealing devices 60 and 61 each have two abutting inflatable ribs or beads 80 and 81, which are inflated via inlets 83 (Mg. 8) will. These sealing devices are in the German patent application filed at the same time .'....... {corresponding to British patent application 30 254/71); Internally the carbonization furnace becomes a sub-atmospheric one Maintain pressure to reduce the risk of gas leakage ■ into the atmosphere.

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Graphite rods 68 extend transversely in the upper Half of the carbonization furnace to get that through this Bear half running sliver.

When operating the device, the fibers are from the Storage containers 11 (Fig. 1) with the aid of feed rollers 12 out and through with the help of drive rollers 13 the oxidation furnace 40 pulled through. Then you run through a fiber storage device 105, which follows geneaier is described, and from there over Feed rollers 13 and drive rollers 25 through the Carbonization furnace 56 to the whitening devices 26a.

The fiber storage device 105 has a roller 90 around which the exiting from the oxidation furnace Fibers running around. The roller 90 can be driven by suitable conventional drive means (not shown) under the furnace backwards and forwards from its position shown in Fig. 1 to a position longitudinally the dotted lines to store the fibers under the oxidizer.

The memory device 105 allows the relative flow rates through the oxidation and Carbonization furnace varies v / ground. While the roller 90 is moved to the left as shown in FIG. 1, the rate of passage through the Carbonization furnace lower than that by the oxidation furnace. While the roller 90, however, according to FIG. is moved to the right, the stored fibers are released and the throughput speed through the Carbonization furnace is higher than that by the Oxydati on the oven.

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The storage device 105 thus acts as an intermediate store for a sliver or slivers. The speed the pick-up and release of the pastes is adjustable.

The use of the oxidation oven and the carbon! heating furnace for making carbon fibers will now be described with reference to Mg.

A number of νυύ fiber tows that contain several slivers form, each of which is preferably made from a large number of tow yarns, in particular from polyacrylonitrile, consists, are pulled out of the storage containers 11 and via a slip-on gate 26 to the Rollers 12 out. The tow yarns are fed to the rollers in the form of a flat sliver or flat sliver fed, which consist of the tow yarns arranged side by side. Every tow can represent a bundle of several hundred thousand polyacrylonitrile filaments.

The flat sliver or slivers of fiber are with the help of the rollers 12, 13 and 25 by the The oxidation furnace and the coloring furnace moved through it, the speed of the rollers being adjustable so that the sliver or slivers may be subjected to tension or relaxation in passage through the device.

The sliver or slivers are introduced into the oxidation furnace and when passing through it Oven carried by the guide rods 53 and the deflectors 55.

Heated oxidizing gas is several times with the help of

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Fans and deflectors 55 through the fiber ribbon or ribbons bindureb moves, whereby a controlled oxidation of the fibers is effected. The temperature of the oxidizing gas is preferably more than 200 ⁰ O.

The speed j with which the oxidizing gas is moved through the fibers is such that the heat build-up in the fibers due to the exothermic reaction is prevented, the temperature can be regulated within £ 2 ⁰ G in relation to the selected temperature and the uniform distribution of the oxidizing gas on all fibers is ensured.

Much of the oxidizing gas is returned after it has passed through the fibers. the Oxidation reaction is exothermic, and temperature control is maintained by heating elements and controlled heat dissipation through the furnace housing.

The gases evolved during the oxidation reaction are in a gas / ash system or in an incinerator in a side stream of the oxyäationsofen peeling oxidizing. Gas transferred. The removal of the oxidizing gas is regulated so that the required oxygen content in the recycled oxidizing gas is maintained. If necessary you can mix nitrogen into the air or, in the case of a "continuous" reaction, this air through Replace nitrogen to suppress the oxidation reaction To keep control.

The fibers run through the oven at a set speed so that when they leave the oven they will leak, are oxidized to the required degree.

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The oxidized 'fibers are, as mentioned, transferred to the carbonization furnace, where they as a result of Running through the temperature gradient τοη room temperature to su a temperature in the order of magnitude of 1500 ° C are carbonized. The carbonization takes place for the purpose of preventing combustion in an inert gas. The inert gas, for example nitrogen, " is fed continuously into the carbonization furnace and withdrawn from the central part of the furnace along with the gases formed during carbonization. The gases formed, which contain hydrogen cyanide and ammonia, are used as scrubbing devices or incinerators.

Those exiting from the end of the carbonization chamber Carbon fibers are cooled in an inert atmosphere in a cooling section 69 to a temperature in some cases they will not be oxidized when they enter the atmosphere. The fibers run through the carbonizing furnace at a speed set so that that different from carbon chemical elements are essentially removed.

The invention is not limited to the features of the above embodiments. For example must the temperatures and times used do not necessarily have the values mentioned. The final carbonation door opening can be 1500 to 3000 0, for example.

The device described above can also be used for the production of carbon fibers from fibers,

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which are not made of polyacrylonitrile. For example any fibers conventionally used for carbon fiber production used type are processed.

The fiber drive devices 12 and 13 as well as in particular 25 (all Fig. 1) need not necessarily have the shape shown and can be used as flat drive belts which move at the same speed as the fiber and which move with the fiber * kept in contact by weights or rollers; by this arrangement, the advancement of the sliver or the fiber ribbons are effected without the ribbons being subjected to a deflection.

Although the apparatus of the above example for processing fiber tow, such as fiber tow for the staple fiber production is applied, the invention relates to the same extent an apparatus for processing a yarn made from continuous filaments and other fiber materials. In order to process such a yarn, for example, the device can be constructed so that there are several a hundred parallel warp yarns in a horizontal plane.

All parts of the oxidation furnace which contain hydrogen cyanide or ammonia come into contact, -can be lined with polytetrafluoroethylene.

The inventive device provides a convenient means for the continuous conversion of large Amounts of commercially available fibers are available in high strength carbon fibers.

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Claims (11)

Claims 1. Device for the production of carbon fibers by Oxidation and carbonization of fibers whose molecular chains mainly contain carbon atoms, consisting of a) an oxidation furnace which has a first housing enclosing an elongated oxidation chamber, Sealing devices of the type described in the patent application (corresponding to British Patent application 30 254/71) described type at the inlet and outlet ends of the oxidation chamber, the on the one hand allow the passage of a sliver and on the other hand the ends of the oxidation chamber substantially seal, and e.a means for passing heated oxidizing agent therethrough Has gas through the sliver in the oxidation chamber, b) an oxygenation furnace connected downstream of the oxidation furnace, which is an elongated one Second housing enclosing carbonization chamber, sealing devices of the patent application (corresponding to British patent application 30 254/71) Type at each end of the case that the traverse a sliver .gestatten and on the other hand the inlet and outlet ends of the carbonation chamber substantially seal, a means of maintaining an inert 209883 / 1iU 9 Atmosphere in the carbonization chamber, a device for maintaining a die Carbonization causing temperature in the carbonization chamber and one between the Cooling means located at the outlet end of the second housing and the sealing device of the strip of carbon fibers obtained except for a temperature which no longer causes oxidation has, as well as c) completely outside the oxidation furnace and the Carbonization chamber arranged devices to the slivers at regulated, preselected Velocities and tensions in the longitudinal direction through the sealing devices, the Oxidation chamber and the carbonization chamber to move. 2. Device according to claim 1, characterized in that that the slip-on creel for the production of the tape or tapes from packaged V / erggarnen or is made of threads wound in packs and creates a retarding force through friction which is effected by making the ribbons via convex, concave and flat deflector rods which are arranged in a frame that is in front of the first at a regulated speed operated roller assembly is located. 3. Apparatus according to claim 1 and 2, characterized in that the oxidation furnace is located in the Extending longitudinally, dividing the oxidation chamber into an upper and a lower chamber space 209883 / itUn ^ Has partition that is divided into two longitudinal pieces a space between these pieces near the center of the longitudinal axis of the oxyda- ' tion chamber divided for the flow of a gas from the lower chamber space in the upper Kainmerraum is that the sealing device is separated from the oxidation chamber by a gap-like opening which introduces a sliver running through it into the upper chamber space and that means at each end of the oxidizing chamber for introducing oxidizing gas into the lower chamber space and a device for removing the gas from the upper chamber space are provided, wherein the gas flows through a cold trap, which the separation of impurities allowed by the returned oxidizing gas, which then through the lower Kainmerraum, through the spaces between the sections of the partition walls and through the sliver flows through and out of the upper chamber space. 4. Apparatus according to claim 1 to 3> characterized in that that Umlenkeinriclitungen in the upper chamber space the gas from the space above the sliver guide through the sliver. 5. Apparatus according to claim 1 to 4, characterized in that guide rods q.uer through the oxidation furnace get lost. 6. Apparatus according to claim 1 to 5, characterized in that that facilities for heating the carbp 209883/1049 .. nization chamber as well as support devices at longitudinal intervals are provided over the entire length of the carbonization chamber. 7. Device according to claim 1 to 6, combined with a device between the outlet end of the Oxy dationskammer and the JJinlaßende said carbonization sum guiding a sliver from one chamber to the other, wherein the wound is a sliver, the iJinrichtung a plurality of spaced-apart rollers, can be, as well as a device for moving the middle of three of the V / alzen back and forth with respect to the other two adjacent rollers and thus to increase the distance that must be traversed by the belt between the two outer rollers. 8. Apparatus according to claim 7, characterized in that the moving roller under the three V / alzen after can be moved backwards and forwards under the oxidation chamber. 9. Process for the production of carbon fibers, thereby characterized in that one is an endless sliver consisting predominantly of fibers containing carbon atoms consists, moved along a path in the closed space, an oxidizing gas through the Lets tape flow, then leads the tape through an inert atmosphere at a Venperatur where the fibers are carbonized, and the fibers cools below the oxidation temperature before exposing it to an oxidizing atmosphere. 209883 / IfU fl 10. The method according to claim 9, characterized in that that the fibers are heated to temperatures of about 1500 to about 3000 0 in the inert atmosphere and it cools Ms to about 100 ° G or below, before exposing them to an oxidizing atmosphere, 11. Ancestors according to claim 9 and 10, characterized in that that the fibers to be carbonized are polyacrylonitrile fibers are. 2 η ώ π κ rw 1 ru a