JP4494511B2 - Horizontal heat treatment apparatus for yarn and method for producing carbon fiber - Google Patents

Description

  The present invention relates to a horizontal heat treatment apparatus for heat treating yarns and a carbon fiber production method using the same heat treatment furnace, and in particular, a horizontal type which ensures the sealing performance of the heat treatment furnace and has excellent heat treatment temperature stability in the furnace. The present invention relates to a heat treatment apparatus and a carbon fiber manufacturing method.

  In general, when a yarn is manufactured, various heat treatments are performed for the purpose of improving its physical properties or drying. In particular, in the production of carbon fibers having excellent mechanical properties, heat treatment at a high temperature is required. For example, in the production of carbon fibers using synthetic fibers as starting materials, the yarns of the fibers are in an oxidizing atmosphere. Flameproofing treatment or infusibilization treatment under heat treatment at 150 to 400 ° C., carbonization treatment for heating the yarn obtained by the above treatment to 900 to 2000 ° C. under an inert atmosphere, and further necessary Accordingly, heat treatment such as graphitization treatment is performed in which the yarn obtained by the treatment is heat-treated in an inert atmosphere of 2000 to 3000 ° C.

  Such heat treatment of the yarn is performed in a heat treatment apparatus that satisfies the respective treatment conditions. In order to stabilize the quality of the yarn obtained by the heat treatment, the treatment chamber of the heat treatment apparatus has a predetermined temperature. In addition, it is essential to keep the room temperature constant during the heat treatment of the yarn. For this reason, for example, in a heat treatment apparatus that continuously treats the yarn, a circulation path is provided inside and outside the heat treatment apparatus, the treatment gas is circulated and used while being heated by a heater, and heat is discharged from the heat treatment apparatus. By reducing the amount as much as possible, the controllability of the heat treatment temperature is improved and the temperature is kept constant.

  Here, the heat treatment apparatus requires an inlet portion and an outlet portion of the yarn for continuously introducing and leading out the yarn. Generally, the inlet portion and the outlet portion are provided with a sheet-like yarn. In many cases, it is opened in a slit shape so as to enable introduction and extraction. Since the opening size of the slit is naturally set larger than the overall sheet cross-sectional shape of the introduced yarn so that the introduction and withdrawal of the yarn can be carried out without difficulty, it is between the slit and the yarn. When a gap is formed and the inlet and outlet portions do not have sealing means, the heat treatment gas leaks out of the apparatus or the outside air flows into the apparatus.

  For example, in the above flameproofing treatment, acrylonitrile-based synthetic fibers are heated and oxidized to generate harmful components such as cyanide, ammonia, and carbon monoxide, so that the heat treatment gas leaks out of the furnace as described above. Doing so will adversely affect the working environment around the heat treatment furnace. In addition, when outside air flows into a high-temperature furnace, the temperature distribution in the furnace is not uniform, and as a result, the quality of the flameproofing product is degraded.

  For this reason, in order to solve the above-mentioned problem, for example, Japanese Patent Publication No. 3-4832 (Patent Document 1), Japanese Patent Publication No. 3-4833 (Patent Document 2), or Japanese Patent Publication No. 3-4834 (Patent Document 1). A horizontal flameproofing furnace has been proposed in which seal chambers are installed at the inlet and outlet of the acrylonitrile-based synthetic fiber as disclosed in Document 3) and the heat treatment gas flows in parallel to the running direction of the yarn. Yes.

  FIG. 4 is a vertical sectional view of a horizontal heat treatment furnace disclosed in these patent documents, and FIG. 5 is a top view thereof. This horizontal heat treatment furnace 1 has a heat treatment chamber 2, and the heat treatment chamber 2 has blow outlets 3 a to 3 d arranged in multiple stages in the upper and lower sides for supplying a heat treatment gas to the front surface thereof, and a rear surface of the heat treatment chamber 2. Intake ports 4a to 4d arranged in multiple stages above and below for exhausting the heat treatment gas out of the heat treatment chamber, and the front side of each of the outlets 3a to 3d and the rear surface of each of the intake ports 4a to 4d The fiber inlet portions 7d to 7h and the outlet portions 7e to 7i are alternately arranged on the side, and seal chambers 5a and 5b are provided to seal the inlet / outlet portions 7d to 7i, respectively.

  The front and rear surfaces of the seal chambers 5a and 5b are provided with slits 7a to 7f, which are multistage fiber inlets and outlets, alternately in the height direction, and the fibers are arranged outside the seal chambers 5a and 5b. Guided by the rollers 8a and 8b. The fiber introduced from the uppermost slit 7a provided in the inlet-side seal chamber 5a is led out from the uppermost slit 7j of the opposite outlet-side seal chamber 5b, guided by the roller 8b, and turned 180 °. The heat treatment chamber 2 is again introduced from the slit 7k one step below the slit 7j. This zigzag running is repeated, and the fibers are sufficiently heated and oxidized in the heat treatment chamber 2 and finally sent out from the lowermost slit 7l.

  On the other hand, the heat treatment gas used for the heat treatment of the fibers is heated to 200 to 300 ° C. by the heater 9 installed in the hot air circulation path outside the heat treatment chamber, and then the outlets 3 a to 3 d by the circulation fan 10. The air is blown out in a direction parallel to the traveling direction of the fibers and supplied to the heat treatment chamber 2. The heat treatment gas used for the fiber heat treatment is sucked from the intake ports 4a to 4d and returned to the heater 9 for circulation.

  Here, in the heat treatment furnace 1 disclosed in Patent Document 2, partition plates 9a to 9d are installed in the respective seal chambers 5a and 5b so as to divide the fiber passages into upper and lower portions, and the seal chamber 5a. , 5b are divided into a plurality of small chambers, and seal chambers 5a-1 and 5b are provided with seal gas exhaust ports 5a-1 to 5a-3 and 5b-1 to 5b-3. Sealed exhaust fans 12a and 12b are installed downstream of the exhaust ports 5a-1 to 5a-3 and 5b-1 to 5b-3, and the gas in the seal chambers 5a and 5b is provided by the sealed exhaust fans 12a and 12b. Is exhausted outside the furnace.

  At this time, the pressure in each of the small chambers is adjusted by an exhaust mechanism such as a valve provided at the outlet of each of the exhaust ports 5a-1 to 5b-3, and the gas outside the furnace passes through the slits 7a to 7l. It is controlled so that it does not flow in or the gas in each chamber does not blow out around the outside of the furnace.

  By controlling the internal pressure of each small chamber, in the heat treatment furnace 1, it is possible to effectively suppress the gas in the furnace from leaking out of the furnace or flowing outside air into the furnace. The working environment around the heat treatment chamber 2 is not contaminated by harmful components, and at the same time, the uniformity of the temperature distribution in the heat treatment chamber 2 is ensured.

Japanese Patent Publication No. 3-4832 Japanese Patent Publication No. 3-4833 Japanese Patent Publication No. 3-4834

  In the heat treatment furnace of the prior art described above, by exhausting the gas in the seal chamber from the exhaust port for the seal gas, the outside air is prevented from flowing into the heat treatment chamber to ensure the uniformity of the temperature in the heat treatment chamber, In addition, it is possible to prevent the gas in the furnace from leaking out of the furnace, but in order to reliably prevent the inflow of the outside air and the leakage of the gas in the furnace, the set value of the pressure in the seal chamber is heat treated. It is necessary to exhaust the gas in the seal chamber sufficiently lower than the pressure in the chamber.

  Then, a considerable amount of high-temperature gas is exhausted from the heat treatment chamber to the outside of the furnace through the seal chamber at the same time as the exhaust, but in order to ensure a certain flameproofing treatment amount of the fiber, It is necessary to newly heat a gas corresponding to the amount of gas exhausted in the furnace and supply it to the heat treatment chamber. For this reason, in the said heat processing furnace, it leads to the big loss of a calorie | heat amount.

  On the other hand, on the downstream side of the exhaust port for the seal gas, in order to treat harmful components such as cyanide, ammonia, and carbon monoxide contained in the treated gas flowing into the seal chamber from the heat treatment chamber, Normally, a gas processing facility is installed. However, if the amount of exhaust gas increases, the processing capacity of the gas processing facility is inevitably increased, and the size is increased.

  However, if the pressure of the seal chamber is increased as much as possible and the pressure difference with the pressure of the heat treatment chamber is reduced in an attempt to reduce the exhaust amount of the gas, for example, the seal chamber temporarily changes due to fluctuations in the pressure of the heat treatment chamber. The pressure of the air tends to be higher, and the outside air flows into the heat treatment chamber through the seal chamber. Since the temperature of the outside air is considerably lower than the temperature of the heat treatment chamber, not only the uniformity of the temperature of the heat treatment chamber is hindered by the inflow of the outside air, but also the temperature of the indoor gas needs to be raised. In addition to reducing quality, processing efficiency is significantly reduced.

  The present invention has been made to solve such a problem, and its specific purpose is to reliably prevent the entry of outside air into the heat treatment chamber and to reduce the amount of gas exhausted from the heat treatment chamber via the seal chamber. It is an object of the present invention to provide a horizontal heat treatment apparatus and a carbon fiber manufacturing method capable of improving the uniformity and controllability of the temperature of the heat treatment chamber and reducing the load on each component device.

Means and effects for solving the problems

The object is achieved by the inventions described in claims 1 and 2 of the present application.
The invention according to claim 1 has an inlet portion and an outlet portion of the running yarn, and constitutes a heat treatment chamber inside and a part of a circulation path for circulating the heat treatment gas inside and outside the heat treatment chamber. At least one of a first seal chamber disposed adjacent to the yarn inlet portion and the outlet portion of the heat treatment chamber, and a second seal chamber disposed outside the first seal chamber. A horizontal heat treatment apparatus comprising two chambers for continuously heat treating the yarn in the heat treatment chamber, wherein each of the first and second seal chambers is provided continuously in the yarn running direction, and is used for sealing gas. The heat treatment chamber has an exhaust port for blowing the heat treatment gas from the fan chamber into the heat treatment chamber, and an air intake port for discharging the heat treatment gas to the fan chamber, The fan chamber is circulated through a circulation exhaust fan A circulating process gas exhaust port for exhausting a certain amount of body has a heater, a circulation fan, it is circulated to the heat treatment gas wherein the blowing mouth discharged from the air inlet, the circulating process gas An exhaust outlet is arranged on the upstream side of the heater, and is a horizontal heat treatment apparatus for yarn.

  Appropriate sealing means is applied to each of the sealing chambers, and two or more sealing chambers are connected to each of the yarn inlet and outlet portions of the heat treatment chamber. Even if one seal chamber serves as a buffer, and the pressure of the heat treatment chamber is higher than the pressure of the outside air and the processing gas from the heat treatment chamber leaks into the first seal chamber, Since the gas flows out to the outside through one or more seal chambers that are connected to each other, the amount of gas flowing out of the apparatus is significantly larger than that in the case of providing a single seal chamber as in the prior art. Can be reduced.

  On the other hand, even if the pressure of the heat treatment chamber is lower than the pressure of the outside air and the outside air flows into the heat treatment chamber, it must pass through one or more seal chambers before reaching the adjacent first seal chamber. The amount of outside air flowing into the heat treatment chamber via the first seal chamber adjacent to the heat treatment chamber is also greatly reduced.

  Therefore, the leakage of the high temperature gas from the heat treatment chamber and the inflow of the low temperature outside air into the heat treatment chamber can be suppressed as much as possible, so that the heating of the gas can be performed efficiently and at the same time the temperature of the heat treatment chamber can be reduced. Controllability and uniformity are improved, stable yarn heat treatment can be realized, and a good environment around the heat treatment apparatus can be maintained.

In this invention, it exists in the circulation path of the said heat processing gas, and has the exhaust port for circulation processing gas in the upstream of the said heating part.
In the heat treatment of the yarn, various heat treatment gases are generated depending on the yarn components, the temperature in the heat treatment chamber, or the heat treatment gas. For example, when the yarn is heat-treated, various components adhering to the yarn cause a chemical reaction to generate various types of gases.
In the production of carbon fiber, heat treatment of the yarn is performed in a high temperature atmosphere, particularly using heated air, etc., so that an oxidizing gas with the yarn components is generated.

  Thus, various kinds of gases increase in the heat treatment chamber over time, the purity of the heat treatment gas cannot be maintained constant, and uniform treatment of the yarn cannot be expected as it is. Therefore, when the amount of other gases mixed in the heat treatment chamber exceeds a predetermined value, a certain amount of new heat treatment gas is supplied to the heat treatment chamber via the circulation path and corresponds to the supply amount. It is necessary to exhaust the circulation processing gas to the outside of the apparatus.

  In the present invention, an exhaust port for circulating process gas is provided in the circulation path, and the exhaust port is opened as necessary, and a part of the circulating process gas is exhausted from the exhaust port. The exhaust port is provided on the upstream side of the heating unit disposed in the circulation path, and a relatively low-temperature circulation process gas is exhausted outside the apparatus, so that the heat efficiency of the heat treatment chamber is greatly affected. There is nothing. In addition, since harmful components may be generated by the heat treatment of the yarn as described above, a gas treatment facility is installed on the downstream side of the exhaust port for the circulation treatment gas.

In the present invention, at least the first seal chamber and the second seal chamber are each provided with a seal gas exhaust port.
If the seal gas is exhausted through the exhaust port for each seal chamber while adjusting the exhaust amount, the pressure in each seal chamber can be set independently. Accordingly, it is possible to set the pressure of each seal chamber corresponding to various seal requirements, so that the outside air flows into the heat treatment chamber through the seal chamber, or the process gas in the heat treatment chamber is supplied to the apparatus. Leakage outside can be reliably prevented, loss of heat can be reduced, and a good working environment can be maintained.

  For example, in order to ensure the uniformity of the temperature of the heat treatment chamber, when preventing the outside air from flowing into the heat treatment chamber through the seal chamber, the pressure of the seal chamber arranged on the outside air side is set higher than the pressure of the outside air. Set. Alternatively, in order to prevent the outside air from flowing into the heat treatment chamber even if it flows into the seal chamber arranged on the outside air side, the amount of gas discharged from the exhaust port of the seal chamber adjacent to the heat treatment chamber can be adjusted. The pressure in the seal chamber is set lower than the pressure in the heat treatment chamber.

  The exhaust from the exhaust port of each seal chamber is, for example, an air volume control device such as a damper or a valve and an exhaust fan installed on the downstream side of each exhaust port, and a predetermined amount of gas is supplied by these devices. This is done by positively exhausting the air from each exhaust port to the outside of the seal chamber.

  In the present invention, the first seal chamber is disposed adjacent to the heat treatment chamber, and the seal gas is disposed between the first seal chamber and the heating unit disposed in the circulation path of the heat treatment gas. It is preferable to provide an exhaust introduction path for introducing the exhaust from the exhaust port to the heat treatment chamber.

  In the heat treatment of the yarn, in order to prevent the processing gas in the heat treatment chamber from leaking to the outside and to prevent the outside air from flowing into the heat treatment chamber, the amount of gas discharged from the exhaust port of each seal chamber is set as described above. Although it is possible with proper adjustment, exhaust from the sealing chamber itself is a waste of heat. For example, if the pressure in the first seal chamber is set to be lower than the pressure in the heat treatment chamber, the amount of gas discharged from the heat treatment apparatus to the outside through the seal chamber naturally increases. When the amount of the processing gas consumed by this heat treatment is exceeded, it becomes difficult to perform stable heat treatment of the yarn, and the amount of heat flowing out of the heat treatment apparatus increases.

  Therefore, in the present invention, an exhaust introduction path is provided between the seal gas exhaust port of the first seal chamber adjacent to the heat treatment chamber and the heating unit in the circulation path, and the exhaust from the exhaust port enters the circulation path. If the yarn is recycled and used for heat treatment of the yarn, it is possible not only to suppress the escape of heat in the heat treatment chamber, but also to enable efficient use of heat energy, as well as uniformity and controllability of the temperature in the heat treatment chamber. Can also be improved.

  If the pressure in the first seal chamber is set lower than the pressure in the second seal chamber, outside air flows into the first seal chamber via the second seal chamber. Then, since the exhaust from the exhaust port of the first seal chamber contains a considerable amount of air, for example, when heat treating the yarn in an oxidizing atmosphere, the exhaust introduction path is necessary for the heat treatment. It can also function as a simple air supply path.

  In the present invention, it is preferable that an inlet portion and an outlet portion of the traveling yarn are provided in multiple stages alternately on the front and rear surfaces of the heat treatment chamber, and the yarn led out from the outlet portion at the front stage of the heat treatment chamber is The traveling direction is changed and introduced into the inlet of the next stage of the heat treatment chamber. For this reason, it is possible to secure a sufficient time for heat treatment of the yarn, and the heat treatment chamber can be saved in space without becoming extremely long in the running direction of the yarn, and the change in the running direction of the yarn can be achieved. Usually, a guide member such as a roller is arranged in the vicinity of each entrance / exit part of the yarn.

  In the present invention, a partition plate for partitioning the passage of the traveling yarn is provided in either the first seal chamber or the second seal chamber, and a seal gas exhaust port is provided for each partition. Preferably it is.

  In order to reliably prevent the flow of outside air into the heat treatment chambers through the respective seal chambers when the yarn inlet and outlet portions are provided in multiple stages on the front and rear surfaces of the heat treatment chamber, of course, In addition, it is necessary to set the pressure in each seal chamber so that the gas in the heat treatment chamber flows out from all the inlet and outlet portions of the yarn into the seal chamber.

  Therefore, as described above, each passage of the running yarn in the seal chamber is partitioned by a partition plate, and a seal gas exhaust port is provided for each partition, and an air volume is provided downstream of each exhaust port. It is preferable to install a control device.

  The air volume control device is operated to adjust the exhaust amount of each section, and the pressure in each section corresponding to each inlet and outlet of the yarn in the heat treatment chamber is equalized. As a result, since both the processing gas and the outside air in the heat treatment chamber can reduce the amount of inflow into each compartment, the amount of gas exhausted from the seal chamber is greatly reduced, and a heat treatment apparatus such as a seal exhaust fan It is possible to prevent the capacity of each component device from becoming larger than necessary.

The invention according to claim 2 uses the horizontal heat treatment furnace according to claim 1 as a flameproofing furnace , and the precursor, which is a raw material of carbon fiber, is oxidized at a temperature of 200 to 300 ° C. in the heat treatment chamber of the flameproofing furnace. It is in the manufacturing method of carbon fiber characterized by performing flameproofing treatment in an atmosphere .

  The carbon fiber is produced, for example, by subjecting a precursor such as acrylonitrile-based synthetic fiber or pitch-based synthetic fiber to a heat treatment such as a flameproofing treatment and a carbonization treatment, and among these, the flameproofing treatment is performed at 200 to 300 ° C. The acrylonitrile synthetic fiber is heat-treated in an oxidizing atmosphere.

  This flameproofing treatment is performed in a predetermined heat treatment furnace, and the furnace and the heat treatment gas can be supplied continuously so that the acrylonitrile-based synthetic fiber can be continuously processed. It is a facility. At this time, naturally, it is indispensable to stabilize the quality of the flameproof fiber produced by the treatment, so that the temperature of the heat treatment furnace is kept constant and the temperature does not become uneven in the furnace. It is necessary to consider as follows.

  In addition, air is used as the heat treatment gas for the flameproofing treatment, and a considerable amount of oxygen is consumed when the fibers are heat treated. For this reason, in order to ensure a constant heat treatment amount of the fiber, new heated air is supplied to the heat treatment chamber to replenish the consumed oxygen, and an amount of furnace air corresponding to the supply amount of the heated air is supplied. It is essential to exhaust the gas outside the furnace.

Furthermore, since harmful components such as carbon monoxide, cyanide, and ammonia are generated in the heat treatment, it is necessary to consider that these harmful components do not leak into the surrounding work environment.
For this reason, in order to realize the flameproofing treatment of acrylonitrile-based synthetic fiber that satisfies such requirements, it is extremely effective to employ the horizontal heat treatment furnace as a flameproofing furnace.

In the present invention, a heat treatment gas equal to or less than the amount of gas introduced from the exhaust introduction path is exhausted from the exhaust port for the circulation process gas.
The exhaust from the first seal chamber contains a gas in the heat treatment chamber, and when the pressure in the first seal chamber is set lower than the pressure in the second seal chamber, the first The seal chamber also contains outside air through the second seal chamber. For this reason, by setting the pressure appropriately, new air necessary for stably performing the flameproofing treatment is introduced from the second seal chamber during the exhaust from the first seal chamber. The air is supplied to the circulation path through the exhaust introduction path.

  At the same time, an amount of gas equal to the amount of new air supplied to the circulation path is exhausted from the exhaust port for circulating process gas, which is the exhaust port of the heat treatment chamber. Therefore, as in the present invention, if the exhaust amount of the gas from the exhaust port is adjusted to be equal to or less than the amount of gas introduced from the exhaust introduction path, the introduction amount and the exhaust amount of the introduced gas are reduced. The difference is inevitably occupied by the gas flowing out from the heat treatment chamber to the first seal chamber, and the gas continuously circulates through the heat treatment chamber, the first seal chamber, and the circulation path. For this reason, if the exhaust amount from the exhaust port for the circulating process gas is adjusted as described above, the outflow of gas from the heat treatment chamber to the first seal chamber can be prevented.

At this time, in the present invention, it is preferable to control the exhaust amount so that the pressure in the first seal chamber is 0.2 to 5 (Pa) lower than the pressure in the heat treatment chamber.
That is, when the pressure difference between the pressure in the first seal chamber and the pressure in the heat treatment chamber is smaller than 0.2 Pa, the pressure in the first seal chamber temporarily increases when the pressure in the heat treatment chamber fluctuates. Therefore, the outside air easily flows into the heat treatment chamber through the first seal chamber, and not only the temperature distribution in the heat treatment chamber is not constant, but also changes in the components of the heat treatment gas, making stable treatment difficult. Become. On the other hand, if the pressure difference is larger than 5 Pa, the amount of gas flowing from the heat treatment chamber to the first seal chamber becomes excessive, and stable heat treatment cannot be performed. The load of the increase will not like.

In the present invention, the exhaust amount is controlled so that the pressure in the second seal chamber is 0.2 to 5 (Pa) higher than the pressure in the first seal chamber.
As described above, in the heat treatment furnace, in order to improve the sealing performance of the heat treatment chamber, two seal chambers are provided on each of the front and rear surfaces of the heat treatment chamber, and the second seal chamber is adjacent to the first seal chamber. It is arranged. Also in the second seal chamber, the gas in the seal chamber is continuously exhausted by the seal exhaust fan and the air flow control device installed downstream of the exhaust port through the seal gas exhaust port.

  The pressure in the second seal chamber prevents leakage of gas in the heat treatment chamber to the outside of the furnace and supplies air necessary for stable heat treatment of the fibers to the circulation path through the first seal chamber. Therefore, it is set lower than the pressure of the outside air and higher than the pressure of the first seal chamber. If the pressure in the second seal chamber at this time is set to be 0.2 to 5 (Pa) higher than the pressure in the first seal chamber, air may flow more than necessary from the second seal chamber to the first seal chamber. In addition, the amount of exhaust from the first seal chamber can be reduced as much as possible, and the pressure in the second seal chamber is always higher than the pressure in the first seal chamber even when the pressure in each seal chamber fluctuates temporarily. Highly maintained, the gas in the heat treatment chamber does not flow out to the second seal chamber through the first seal chamber. Therefore, most of the gas in the second seal chamber is occupied by air, and the exhaust does not contain harmful components, so that it is not necessary to process the gas with gas processing equipment.

1 is a side view of a horizontal heat treatment furnace that is a typical embodiment of the present invention. It is a front sectional view of the horizontal heat treatment furnace. It is a side view of the horizontal type heat treatment furnace which is another Example of this invention. It is a side view of the conventional horizontal heat treatment furnace. It is a top view of the horizontal heat treatment furnace.

  Preferred embodiments of a horizontal heat treatment furnace of the present invention will be described below in detail with reference to the accompanying drawings. In the present embodiment, the case where the acrylonitrile-based synthetic fiber is flameproofed in a horizontal heat treatment furnace will be described, but the horizontal type of the present invention can be selected by appropriately selecting the type of heat treatment gas or the heat treatment temperature. The heat treatment furnace can also be used as a heat treatment furnace for other fibers.

  FIG. 1 shows a side view of a horizontal heat treatment furnace as a typical embodiment of the present invention, and FIG. 2 shows a front sectional view of the horizontal heat treatment furnace. In these drawings, substantially the same devices as those in the prior art shown in FIGS. 4 and 5 are denoted by the same reference numerals.

  The horizontal heat treatment furnace 1 has a heat treatment chamber 2, and the heat treatment chamber 2 has a heat treatment gas blow-out port 3 at an upper portion thereof and an intake port 4 for exhausting the gas in the heat treatment chamber to the outside thereof. In addition, slit-like fiber inlet portions 7g to 7i and outlet portions 7j to 7l are provided on the front and rear surfaces of the heat treatment chamber 2. Furthermore, first seal chambers 5a and 5b for sealing the fiber inlet portions 7g to 7i and the outlet portions 7j to 7l are disposed adjacent to the heat treatment chamber 2 on the front and rear surfaces of the heat treatment chamber 2, Second seal chambers 6a and 6b are connected to the outside of the first seal chambers 5a and 5b, respectively.

The first and second seal chambers 5a, 5b and 6a, 6b are provided with slits 7d-7f, 7m-7o, 7a-7c, 7p-7r in the height direction on the front and rear surfaces thereof. The fiber is introduced and led out from the slits 7a to 7r.
Specifically, the fiber is first introduced from the uppermost slit 7a on the front side by rollers 8a and 8b arranged outside the second seal chambers 6a and 6b, respectively, and finally the lowermost step on the rear side. Although the fiber is led out from the slit 7q to the outside of the furnace, the details of the fiber introduction and lead-out method by the rollers 8a and 8b are the same as those in the prior art described above, and the description thereof is omitted here. The slits 7a to 7r have a structure that can be adjusted in the vertical direction so that the opening dimensions thereof can be changed according to the thickness of the fiber.

Air is used as the heat treatment gas used for the heat treatment of the fibers, and is heated to 200 to 300 ° C. by a heater 9 provided in a circulation path connecting between the heat treatment chamber and the outside. Is supplied to the heat treatment chamber 2 from the outlet 3.
And the said heat processing gas is used for the heat processing of a fiber, and the gas in the heat processing chamber which generate | occur | produces by this processing is discharged | emitted from the inlet 4 to a circulation path.

  The seal chambers 5a, 5b and 6a, 6b are provided with seal gas exhaust ports 5a-1 to 5b-2 and 6a-1 to 6b-2, respectively, and seal gas exhaust ports 5a-1 to 5b. -2 and 6a-1 to 6b-2, the seal exhaust fans 12 and 13a and 13b installed outside the furnace exhaust the gas in the seal chambers 5a to 6b by a preset amount, The pressure in the seal chambers 5a and 5b is controlled to be lower than the pressure in the heat treatment chamber 2, and the pressure in the second seal chambers 6a and 6b is controlled to be lower than the pressure in the outside air. By doing so, both the outflow of gas from the heat treatment chamber 2 to the first seal chambers 5a and 5b and the inflow of outside air to the second seal chamber are secured, and the inflow of the outside air into the heat treatment chamber and the heat treatment chamber are ensured. The leakage of gas to the outside of the furnace is reliably prevented.

  Here, the first and second seal chambers 5a, 5b and 6a, 6b are divided into a plurality of fiber passages by partition plates 14a, 14b and 15a, 15b, and the exhaust port 5a-1. ˜6b-2 is provided for each section. And since the air volume control devices 16a to 16d and 17a to 17d such as known dampers or valves are installed at the outlets of the exhaust ports 5a-1 to 6b-2, fine adjustment of the exhaust amount is made for each section. Even when there is a pressure distribution in the height direction of the heat treatment chamber 2, the pressure can be set for each section. Accordingly, the pressure difference between each compartment and the heat treatment chamber 2 is appropriately controlled, and as a result, the exhaust amount from each compartment can be reduced as much as possible, and the exhaust amount from the seal chambers 5a to 6b can be reduced. Significant reduction is achieved.

  The exhausts from the exhaust ports 5a-1 to 5b-2 provided in the first seal chambers 5a and 5b are once joined and then exhausted by the first seal exhaust fan 12. If the exhaust gas is simply discharged to the outside of the furnace, the amount of heat escaped from the heat treatment chamber 2 is increased, resulting in a significant energy loss and a decrease in the controllability of the heat treatment temperature of the fibers. Therefore, in the present embodiment, the exhaust from the first seal chambers 5a and 5b is introduced into the fan chamber 11 through the exhaust introduction path 18 so that the exhaust is circulated and used for heat treatment of the fibers. Yes.

  This means that even if it is required to set the pressure of the first seal chambers 5a and 5b to be considerably lower than the pressure of the heat treatment chamber 2 in order to enhance the sealability of the heat treatment chamber 2, the high temperature Since the gas in the heat treatment chamber circulates through the first seal chambers 5a and 5b, the controllability of the heat treatment temperature can be achieved even if the gas leakage from the heat treatment chamber 2 to the first seal chambers 5a and 5b increases. Less to reduce.

  Here, the pressure in the first seal chambers 5a and 5b is set lower than the pressure in the second seal chambers 6a and 6b, and the heat treatment chamber is provided through the exhaust ports of the first seal chambers 5a and 5b. Since the gas introduced into 2 contains a considerable amount of air through the second seal chambers 6a and 6b, the exhaust introduction path 18 performs a stable flameproofing treatment in the heat treatment chamber 2. It also functions as a supply path for supplying necessary new air.

  On the other hand, the fan chamber 11 is provided with an exhaust port 19 for circulating processing gas, and a certain amount of the circulating processing gas is forcibly exhausted by the circulating exhaust fan 20 installed outside the furnace from the exhaust port 19. Is done. At this time, the amount of exhaust from the exhaust port 19 (hereinafter referred to as “in-furnace exhaust”) is controlled to the same amount as the outside air flowing into the first seal chambers 5a and 5b from the second seal chambers 6a and 6b.

  The exhaust in the furnace is finally exhausted outside the furnace, but since the exhaust contains harmful components such as cyanide, ammonia and carbon monoxide, it must be released into the atmosphere as it is. I can't. For this reason, the exhaust gas is sent to a gas processing facility (not shown) and burned with kerosene to treat the harmful components.

  Here, in order to surely flow out the gas from the heat treatment chamber 2 to the first seal chambers 5a and 5b, the pressure in the first seal chambers 5a and 5b is taken into consideration in consideration of the pressure variation in the heat treatment chamber 2. Is preferably set lower by 0.2 Pa or more than the pressure in the heat treatment chamber 2. However, if the pressure in the seal chambers 5a and 5b is excessively reduced, the amount of the circulation introduction gas increases and the load on the first seal exhaust fan 12 increases, so the difference in pressure is set to 5 Pa or less. It is preferable to do.

On the other hand, with respect to the second seal chambers 6a and 6b, the exhausts from the second seal gas exhaust ports 6a-1 to 6b-2 are merged for each of the compartments, and the second seal exhaust fans 13a and 13b. The air is exhausted by the outside.
At this time, the pressure in the second seal chambers 6a and 6b is set to be 0.2 to 5 Pa higher than the pressure in the first seal chambers 5a and 5b, and the gas is exhausted from the second seal chambers 6a and 6b (hereinafter referred to as “the second seal chambers 6a and 6b”). , Referred to as seal exhaust). That is, if the pressure in the second seal chambers 6a and 6b is set 0.2 Pa or more higher than the pressure in the first seal chambers 5a and 5b, the pressure in the first and second seal chambers 5a to 6b may change. Even if there is nothing, there is no loss of gas from the first seal chambers 5a and 5b in the second seal chambers 6a and 6b, and outside air is surely discharged from the first seal chambers 5a and 5b. The fresh air necessary for the stable heat treatment of the fibers is supplied to the heat treatment chamber 2 through the exhaust introduction path 18. Further, most of the gas in the second seal chambers 6a and 6b is air, and can be directly discharged to the atmosphere without going through the gas processing facility.

  However, if the pressure in the second seal chambers 6a and 6b is excessively increased, the amount of gas flowing out from the second seal chambers 6a and 6b to the first seal chambers 5a and 5b becomes excessive, and the amount of introduced gas for circulation is increased. As the amount increases, the load on the first seal exhaust fan 12 increases, and the amount of air entrained in the circulation exhaust increases. Therefore, the heating energy and the amount of exhaust in the furnace increase, and the load on the gas processing equipment increases. It becomes excessive. For this reason, the pressure difference is preferably 5 Pa or less.

  In the present embodiment, the flow direction of the heat treatment gas in the heat treatment chamber 2 is a direction perpendicular to the fiber traveling direction, but the heat treatment gas blow-out port 3 and the intake port 4 are installed. It is also possible to change the position so that the flow direction of the heat treatment gas is parallel to the fiber running direction.

  Further, although the fiber passage is shown for the heat treatment furnace 1 having three passes, from the viewpoint of the heat treatment efficiency of the fiber, the number of passes can be several passes to several tens passes, and the plurality of fibers can be different passes. You may make it introduce from. As described above, the partition plates 14a to 15d for partitioning the path may be installed only in the heat treatment chamber 2 or in each of the seal chambers 5a to 6b and the heat treatment chamber 2 in addition to being installed only in the seal chambers 5a to 6b. Is possible.

  Furthermore, as shown in FIG. 3, in order to improve the sealing performance of the heat treatment chamber 2, rollers 8a and 8b for introducing and leading out the fibers are arranged in the chambers of the second seal chambers 6a and 6b, and the second seal. It is also possible to reduce the number of openings for introducing and leading out fibers provided on the outside air wall surfaces of the chambers 6a and 6b.

Examples of the present invention and comparative examples will be specifically described below.
Example 1
The width and height of the slits 7a to 7r are 210 mm and 15 mm, the number of fiber passes is 3, the distance between the passes is 150 mm, and the partition plates 14a to 15b are connected to the first seal chambers 5a and 5b and the second seal. A horizontal heat treatment furnace 1 provided between all the paths of the chambers 6a and 6b and having a heat treatment gas blowing direction perpendicular to the fiber running direction was used. The temperature of the heat treatment chamber 2 is 240 ° C. at an atmospheric temperature of 20 ° C., the furnace exhaust amount is 52 Nm ³ / h, the circulation exhaust amount is 46 Nm ³ / h on one side, and the exhaust amounts from the second seal chambers 6 a and 6 b are One side is set to 27 Nm ³ / h, and the air volume control devices 16a to 17d are used to lower the pressure in the first seal chambers 5a and 5b by 0.2 to 0.4 Pa from the heat treatment chamber 2 and the pressure in the second seal chambers 6a and 6b. The amount of exhaust from each compartment was finely adjusted to be 0.2 to 0.5 Pa higher than the first seal chambers 5a and 5b.

  Under these conditions, the acrylonitrile-based synthetic fiber was flameproofed at 240 ° C. As a result, no leakage of gas in the heat treatment chamber from the second seal chambers 6a and 6b to the work environment was observed, and cyan gas was not detected in the exhaust of the second seal chambers 6a and 6b.

(Comparative Example 1)
In the first embodiment, when the furnace exhaust amount was increased to 100 Nm ³ / h, the fine air flow control devices 16a to 16d made fine adjustments in the paths of the first seal chambers 5a and 5b. There was a pass that was higher than the pressure in the heat treatment chamber 2.
When the temperature in the heat treatment chamber of the pass was measured, locations where the temperature was 200 ° C. or less were observed in the vicinity of the slits 7g to 7i and 7j to 7l.
(Comparative Example 2)
In Example 1, when the exhaust amount from the second seal chambers 6a and 6b was increased to 60 Nm ³ / h on one side, the first seal chamber 5a was adjusted despite fine adjustment by the air volume control devices 17a to 17d. , 5b, there is a path higher than the pressure in the second seal chambers 6a, 6b. At this time, cyan gas was detected in the exhaust of the second seal chambers 6a and 6b, and the exhaust treatment was necessary.

DESCRIPTION OF SYMBOLS 1 Horizontal type heat treatment furnace 2 Heat processing chamber 3a-3d Blowing port 4a-4d (gas in a furnace) Intake port 5a, 5b 1st sealing chamber 5a-1-5b-3 Exhaust for 1st sealing gas Port 6a, 6b Second seal chamber 6a-1 to 6b-3 Second seal gas exhaust port 7a-7r Slit 8a, 8b Roller 9 Heater 10 Circulating fan 11 Fan chamber 12a, 12b First seal exhaust fan 13a, 13b Second seal exhaust fan 14a, 14b First seal chamber partition plate 15a, 15b Second seal chamber partition plate 16a-16d First seal chamber air volume control device 17a-17d Second seal chamber air volume control device 18 Exhaust introduction Route 19 Circulating gas exhaust port 20 Circulating exhaust fan

Claims (2)

Having an inlet portion and an outlet portion of the running yarn, and having a heat treatment chamber therein, and a fan chamber which constitutes a part of a circulation path for circulating the heat treatment gas into and out of the heat treatment chamber, the heat treatment Comprising at least two chambers, a first seal chamber disposed adjacent to the yarn inlet and outlet portions of the chamber, and a second seal chamber disposed outside each first seal chamber, the heat treatment A horizontal heat treatment apparatus for continuously heat treating yarn in a room,
Each of the first and second seal chambers is provided continuously in the yarn running direction, and has a seal gas exhaust port.
The heat treatment chamber has a blowout port for blowing the heat treatment gas from the fan chamber into the heat treatment chamber, and an intake port for discharging the heat treatment gas to the fan chamber,
The fan chamber has a circulation processing gas exhaust port for exhausting a certain amount of the circulation processing gas through the circulation exhaust fan, a heater, and a circulation fan, and the heat processing gas is passed from the intake port to the outlet port. And circulate with
The circulation processing gas exhaust port is disposed on the upstream side of the heater.
A horizontal heat treatment apparatus for yarn. The horizontal heat treatment apparatus according to claim 1 is used as a flameproofing furnace, and the precursor which is a raw material of carbon fiber is flameproofed in an oxidizing atmosphere of 200 to 300 ° C. in a heat treatment chamber of the flameproofing furnace. A carbon fiber manufacturing method characterized by the above.

Images