JP2012067419A - Exhaust gas treatment apparatus for carbonization furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas treatment apparatus for a carbonization furnace capable of surely discharging particulate matter such as a silicon compound and tars into a combustion chamber and facilitating maintenance.SOLUTION: An exhaust gas treatment apparatus includes an exhaust gas flow rate regulating valve 20 for regulating the projection amount to a combustion chamber 101 arranged on an upper side of a carbonization furnace 2 to regulate the flow rate of exhaust gas. The exhaust gas flow rate regulating valve 20 includes an operation rod 210 horizontally extending in a second exhaust gas passage 14b from a back-face center constituted of a tapered surface on an opposite side of an opening 101a, crossing a first exhaust gas passage 14a and projecting a distal end operation part 211 on a back face side to the outside of the exhaust gas treatment apparatus.

Description

  The present invention relates to a carbon fiber production apparatus, and an exhaust gas containing a decomposition product generated when carbon fiber is produced by carbonizing a flame-resistant fiber subjected to flame resistance treatment in an inert atmosphere at a high temperature. The present invention relates to an exhaust gas treatment apparatus for a carbonization furnace that combusts and processes.

  Carbon fibers are excellent in specific strength, specific elastic modulus, heat resistance, chemical resistance and the like, and are frequently used as reinforcing materials for various plastic molded products. For example, polyacrylonitrile-based fibers are generally used as precursor fibers, and the carbon fibers are manufactured as follows. First, in the flameproofing step, the precursor fiber is pre-oxidized in air at a temperature of 200 to 300 ° C. to obtain a flameproof fiber. Next, in the carbonization step, the flame resistant fiber is carbonized at a temperature of 300 to 2000 ° C. in an inert atmosphere to obtain a carbon fiber.

  In the flameproofing step, a hot air circulation type flameproofing furnace that circulates hot air of an oxidizing gas is usually used. In this hot air circulation type flameproofing furnace, a large number of precursor fiber bundles, which are precursor fibers, are aligned and run in a heat treatment chamber provided in the flameproofing furnace, and precursors arranged in parallel in a sheet form are run. The body fiber bundle is wound around a large number of rolls provided on one and the other outside the heat treatment chamber, and is run in multiple stages up and down. These precursor fiber bundles that run continuously are heated by blowing hot air of 200 ° C. or more from the vertical direction, and subjected to an oxidation reaction until a desired flame resistance density is achieved, thereby performing a flame resistance treatment.

  The precursor fiber bundle is preliminarily coated with a silicon-based oil agent because the single fibers constituting the precursor fiber bundle are easily stuck together in the flameproofing process. Here, if the flameproofing treatment of the precursor fiber bundle is continued for a long time, the volatile silicon derived from the silicon-based oil agent in the hot air (oxidizing gas) circulating in the flameproofing furnace becomes a high concentration, and the volatile silicon Becomes particulate matter such as a silicon compound and accumulates in the flameproofing furnace. In the flameproofing step, various compounds such as cyanide, ammonia, carbon monoxide and tar (hereinafter abbreviated as “furnace gas”) are produced in the flameproofing furnace by an oxidation reaction of the precursor fiber bundle. appear.

  By the way, high temperature exhaust gas is exhausted from the carbonization furnace where carbonization is performed in order to reduce the gas in the furnace. This exhaust gas also contains the various compounds described above. The exhaust gas is cooled to a predetermined temperature using a heat exchanger, and after particulate matter such as a silicon compound is removed by a filter, the exhaust gas is discharged out of the system. The practical heat resistance limit of the filter is usually about 200 ° C., and if the high-temperature exhaust gas from the carbonization furnace is directly fed into the filter, the function of the filter may be impaired. Further, since the exhaust gas contains sulfur oxides derived from the precursor fiber additive, if the exhaust gas is cooled too much, the exhaust gas may condense in the exhaust passage and the exhaust passage may corrode. There is. Therefore, the exhaust gas delivered from the heat exchanger is adjusted to be in a temperature range of 160 to 180 ° C. by heat exchange.

FIG. 3 schematically shows an example of a carbon fiber production apparatus previously proposed by the present inventors and disclosed in Japanese Patent Laid-Open No. 2009-174077 (Patent Document 1). The carbon fiber production apparatus includes a flameproofing furnace 1 for performing flameproofing treatment of the precursor fiber bundle F by circulating hot air, and a carbonization furnace 2 for carbonizing the flameproofing fiber flameproofed in the flameproofing furnace 1. And the heat exchanger 3 for exchanging heat between the exhaust gas sent from the carbonization furnace 2 and the outside air, and the heated outside air sent from the heat exchanger 3 (heated outside air) to the flameproofing furnace 1 A heated outside air supply passage 4 for supplying air is provided. Further, from the air volume detecting means 5 for detecting the air volume of the heated outside air flowing through the heated outside air supply path 4, the air volume adjusting valve 6 for adjusting the air volume of the heated outside air flowing through the heated outside air supply path 4, and the air volume detecting means 5 And a control means 7 for controlling the air volume adjusting valve 6 based on the above information.

  The flameproofing furnace 1 further includes a heated outside air inlet 8 for supplying heated outside air into the furnace 1 and a hot air outlet for discharging part of the hot air in the flameproofing furnace 1 out of the system. 9 are provided. By discharging hot air containing volatile silicon from the hot air discharge port 9, the concentration of volatile silicon in the hot air flow path is reduced, and flaking of the precursor fiber bundle F and adhesion of foreign matters are reduced. Note that the specific configuration of the flameproofing furnace 1 is described in detail in the above-mentioned Patent Document 1, and is not directly related to the carbonization furnace exhaust gas treatment apparatus of the present invention.

  On the other hand, the exhaust gas discharged from the carbonization furnace 2 is finally discharged from the system via the carbonization furnace exhaust gas treatment device 10, the heat exchanger 3, the temperature detection means 11, the filter 12, and the first blower 13. To be discharged. In the carbonization furnace exhaust gas processing apparatus 10, the exhaust gas from the carbonization furnace 2 is combusted, and cyanide, ammonia, carbon monoxide, tar content, etc. contained in the exhaust gas are decomposed. Specifically, fuel and air are supplied to the combustion chamber 10a of the carbonization furnace exhaust gas treatment device 10, and the fuel is combusted in the combustion chamber. At the same time, the exhaust gas is combusted by introducing the exhaust gas into the combustion chamber 10a. The heat exchanger 3 includes a case and a heat exchange path that penetrates the case, and is between the outside air that flows through the heat exchange path 3a and the exhaust gas that is fed into the heat exchanger 3 from the exhaust gas passage 14. In order to perform heat exchange.

  The filter 12 is installed to remove particulate matters such as silicon compounds. The filter 12 is appropriately selected in consideration of the trapped particle diameter, pressure loss, heat resistant temperature, durability, and the like, but a heat resistant bag filter containing a fluororesin, glass fiber, polyimide, polyphenylene sulfide or the like is preferably used. The temperature detection means 11 is provided for detecting the temperature of the exhaust gas fed into the filter 12. Examples of the temperature detecting means 11 include thermometers such as thermocouples and resistance temperature detectors. The temperature detection means 11 and the second blower 15 are connected via a control means 7 such as an inverter, and the second blower 15 is controlled by a temperature detection signal detected by the temperature detection means 11.

  FIG. 4 shows a schematic configuration of the exhaust gas treatment apparatus 10 for a carbonization furnace previously proposed by the present inventors and published as Japanese Patent Laid-Open No. 2001-324119 (Patent Document 2) as in the above Patent Document 1. This is shown schematically.

  According to the exhaust gas treatment apparatus 10 for a carbonization furnace exemplified here, the exhaust gas generated when the flame resistant fiber that has been subjected to the flame resistance treatment in the previous treatment process is carbonized in the carbonization furnace 2 is carbonized. It is introduced into the combustion chamber 10a through a vertical exhaust gas passage 14a that rises vertically from the furnace 2 and a horizontal exhaust gas passage 14b that extends horizontally from the vertical exhaust gas passage 14a and opens to the combustion chamber 10a. The combustion chamber 10 a is supplied with a mixed gas of air and fuel automatically adjusted to an optimum flow rate ratio by an automatic mixing valve via a fuel pipe 19. The mixed gas supplied through the fuel pipe 19 is burned by a burner (not shown) to ignite the exhaust gas introduced into the combustion chamber 10a and heat the combustion chamber 10a.

In the exhaust gas treatment apparatus 10 for a carbonization furnace shown in FIG. 4, an exhaust gas flow rate adjusting valve 20 is provided inside the horizontal exhaust gas passage 14b. This exhaust gas flow rate adjusting valve 20 is for adjusting the flow rate of the exhaust gas introduced from the opening of the horizontal exhaust gas passage 14b into the combustion chamber 10a to an appropriate amount. Conventionally, a butterfly valve, a gate valve, or the like is generally used as an adjustment valve corresponding to the exhaust gas flow rate adjustment valve 20. However, in the example of the exhaust gas flow rate adjusting valve 20 shown in FIG. 4, as shown in the figure, one side in the height direction is connected at right angles to the upper base and the lower base in the side view, and the other side is the above-described opening. It exhibits a trapezoidal shape that is connected by an inclined straight line on the opposite side, and approximates the cross-sectional shape of the horizontal exhaust gas passage 14b in the front view, and the exhaust gas flow rate between the exhaust gas flow rate adjustment valve 20 and the horizontal exhaust gas passage 14b. The regulating valve 20 is a horizontal exhaust gas passage 1
A desired clearance is provided so that the inside of 4b can be slid.

Further, in the illustrated example, a base end of an operating rod 21 extending horizontally across the combustion chamber 10a from the front surface of the exhaust gas flow rate adjusting valve 20 on the combustion chamber 10a side is fixed. The distal end operating portion 21a of the operating rod 21 is extended outside the room, and the distal end operating portion 21a is pushed / pulled from the outside to advance / retreat the exhaust gas flow rate adjusting valve 20 in the horizontal exhaust gas passage 14b. The amount of exhaust gas discharged from the exhaust gas flow rate adjusting valve 20 to the combustion chamber 10a is adjusted, and the opening area of the opening of the horizontal exhaust gas passage 14b is adjusted to adjust the exhaust gas emission amount. The exhaust gas flow rate adjusting valve 20 removes particulate matter such as silicon compounds adhering to the vicinity of the entrance of the opening by pushing and pulling the operation rod 21, and scrapes various compounds such as the tar into the combustion chamber 10a. Drop it.
The horizontal exhaust gas passage 14b may have a rectangular, circular, elliptical, or other various cross-sectional shapes. The rectangular or circular cross-section is easy to manufacture and carbonize the horizontal exhaust gas passage 14b. This is preferable because the smoothness of the flow of the exhaust gas from the furnace is obtained.

JP 2009-174077 A JP 2001-324119 A

  In the exhaust gas treatment apparatus 10 for a carbonization furnace disclosed in Patent Document 2, the exhaust gas flow rate adjusting valve 20 has a special shape as described above, so that it is easily attached to the opening of the horizontal exhaust gas passage 14b. Particulate matter such as silicon compounds derived from the oil agent and various compounds such as tars that are generated in the carbonization furnace and accumulated on the inner wall surface of the horizontal exhaust gas passage 14b are efficiently removed into the combustion chamber. Therefore, in particular, the tar content and the like are surely pushed out to the combustion chamber at the front surface of the exhaust gas flow rate adjusting valve 20 without being dropped through the vertical exhaust gas passage 14a onto the flameproof fiber running in the carbonization furnace. It can be discharged to the outside after being burned reliably. As a result, particulate matter such as silicon compounds and tars are less likely to adhere to the carbon fibers passing through the carbonization furnace, resulting in reduced yarn breakage and fluffing, stabilization of the process, and improved yield. .

  However, the operating rod 21 of the exhaust gas flow rate adjustment valve 20 disclosed in Patent Document 2 crosses the combustion chamber 10a from the front surface of the exhaust gas flow rate adjustment valve 20 on the combustion chamber 10a side as described above and shown in FIG. The horizontal exhaust gas 14b is advanced and retracted by extending horizontally and projecting to the outside, and pushing and pulling the tip operating portion 21a of the operating rod 21 from the outside. Therefore, the operation rod 21 is always exposed to a high temperature during the operation of the combustion chamber 10a. Even if a material having excellent heat resistance is used, it is difficult to avoid thermal deformation, and the horizontal exhaust gas passage It becomes difficult to smoothly move back and forth between the opening 14b and the opening along the horizontal exhaust gas passage 14b, and as a result, the horizontal exhaust gas passage due to particulate matter such as silicon compounds accumulated in the opening and the horizontal exhaust gas passage 14b, tar content, etc. It is difficult to adjust the opening formed between the exhaust gas flow rate adjustment valve 20 to a desired area.

  The present invention has been made to solve these problems. Specifically, as described above, the advancing and retreating operation of the exhaust gas flow rate adjusting valve that performs the horizontal operation is smoothed and accumulated in the vicinity of the opening and in the horizontal exhaust gas passage. Provided is an exhaust gas treatment apparatus 10 for a carbonization furnace that can surely discharge particulate matter such as silicon compounds and tar content into the combustion chamber, and at the same time, ensures the durability of the operation rod of the exhaust gas flow rate adjusting valve. The purpose is to do.

This object is a treatment apparatus for exhaust gas discharged from a carbonization furnace that carbonizes flameproof fibers in a high-temperature inert atmosphere, which is a basic configuration of the present invention, and is disposed above the carbonization furnace. A combustion chamber, a first exhaust gas passage rising from a carbonization furnace to a side of the combustion chamber, a second exhaust gas passage extending across the first exhaust gas passage and extending to the opening of the combustion chamber, and the second exhaust gas passage An exhaust gas flow rate that adjusts the flow rate of the exhaust gas by adjusting the amount of protrusion into the combustion chamber by advancing and retreating between the second exhaust gas passage and the combustion chamber across the opening in the passage. The exhaust gas flow rate adjusting valve extends from the back side opposite to the opening across the first exhaust gas passage to the outside of the device, and has a rod-like operating rod having an operating part at the back side end thereof. The exhaust gas treatment device for carbonization furnace , It is effectively achieved.
The first exhaust gas passage that rises to the side of the combustion chamber is preferably raised vertically, but is not necessarily vertical. For example, the first exhaust gas passage may be inclined or bent halfway. Further, the second exhaust gas passage connecting the first exhaust gas passage and the combustion chamber is not necessarily horizontal, and may be disposed, for example, slightly inclined. However, it is necessary to be linear in order to operate the exhaust gas flow rate adjustment valve.

  Further, when the second exhaust gas passage is inclined and arranged, it is preferable that the second exhaust gas passage is inclined downward toward the opening of the combustion chamber. More preferably, the exhaust gas flow rate adjusting valve is formed in a tapered surface inclined downward toward the backward side of the back side of the exhaust gas flow rate adjusting valve.

  Since the present invention has the above-described configuration, the operating rod of the exhaust gas flow rate adjusting valve is accommodated in the second exhaust gas passage and is not directly affected by the high temperature of the combustion chamber, so the durability of the operating rod is greatly increased. Extend to. In addition, the advancing and retreating operation of the exhaust gas flow rate adjustment valve that advances and retreats toward the combustion chamber is also smoothed, and particulate matter such as silicon compounds accumulated in the vicinity of the opening of the combustion chamber and the second exhaust gas passage, tar content, etc. As a result, the yarn is surely delivered into the combustion chamber and subjected to combustion treatment. As a result, yarn breakage and fluffing are reduced, the process is stabilized, high-quality carbon fibers are stably obtained, and the yield is improved.

It is explanatory drawing which shows typically the example of a specific structure of the exhaust gas processing apparatus 10 for carbonization furnaces which is typical embodiment of this invention. It is explanatory drawing which shows typically the suitable modification of the arrangement | positioning aspect of a 2nd exhaust gas passage. It is a block diagram which shows an example of the manufacturing method of the conventional carbon fiber manufacturing apparatus and the same fiber. It is explanatory drawing which shows typically the example of a specific structure of the conventional waste gas processing apparatus for carbonization furnaces.

  Hereinafter, typical embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of an exhaust gas treatment apparatus 100 for a carbonization furnace according to the present invention. Since the detailed configuration not directly related to the characteristic part of the present invention of the exhaust gas treatment apparatus 100 for carbonization furnace is disclosed in the above-mentioned Patent Document 2, the description thereof is omitted here.

According to FIG. 1, the exhaust gas generated when the flame-resistant fiber that has been flame-resistant in the flame-proofing process is carbonized in the carbonization furnace 2 is vertically exhausted that is arranged upright from the carbonization furnace 2. The gas is introduced into the combustion chamber 101 through a horizontal exhaust gas passage 14 b that communicates with the passage 14 a and the vertical exhaust gas passage 14 a and extends horizontally in the combustion chamber 101. The vertical exhaust gas passage 14a corresponds to the first exhaust gas passage in the present invention. However, the first exhaust gas passage does not have to rise vertically, for example, it starts up while being inclined, bent, or curved. You can also.

  Here, the amount of exhaust gas generated in the carbonization furnace 2 and introduced into the combustion chamber 101 from the vertical exhaust gas passage 14a and the horizontal exhaust gas passage 14b is determined according to the temperature in the combustion chamber 101. The supply amount of the mixed gas mixture into the combustion chamber 101 needs to be adjusted appropriately. Air and fuel are mixed through an automatic mixing valve (not shown), and based on temperature information in the combustion chamber 101, the supply flow rate of the mixed gas is automatically controlled by a control mechanism (not shown), and fuel piping 19 is supplied to the combustion chamber 101.

  The combustion chamber 101 is a cylindrical furnace formed of a refractory material such as brick, and is introduced into the combustion chamber 101 through the exhaust gas horizontal exhaust gas passage 14b, as disclosed in Patent Document 2 above. There are provided an opening 101a, an air intake port (not shown) of an air supply pipe 10b for taking in air for burning exhaust gas, and an exhaust port (not shown) for exhausting the burned exhaust gas. The flow rate of the exhaust gas introduced from the opening is adjusted by the exhaust gas flow rate adjustment valve 20 inserted in the opening 101a, and the flow rate of the air taken in from the air intake port is provided in an air supply pipe connected to the air intake port. It is adjusted by the air flow rate adjusting valve 10c.

  The exhaust gas flow rate adjustment valve 20 has the same configuration as the exhaust gas flow rate adjustment valve 20 disclosed in Patent Document 2, and the shape of the exhaust gas flow rate adjustment valve 20 is such that one side in the height direction is an upper bottom and a lower bottom, respectively, in side view. Are connected to each other at right angles, and the other side is connected to each other by an inclined straight line on the opposite side of the opening. In front view, the exhaust gas flow rate adjusting valve is approximated to the cross-sectional shape of the horizontal exhaust gas passage 14b. A desired clearance is provided between 20 and the horizontal exhaust gas passage 14b so that the exhaust gas flow rate adjustment valve 20 can slide inside the horizontal exhaust gas passage 14b.

  Here, in the present invention, the operating rod 210 extends horizontally across the vertical exhaust gas passage 14a from the center of the tapered surface which is the back surface of the exhaust gas flow rate adjusting valve 20 on the vertical exhaust gas passage 14a side. The operation portion 211 on the end side is greatly different from the operation rod 21 disclosed in Patent Document 2 in that it extends outside the room. As in Patent Document 2, the operation unit 211 of the operation rod 210 is pushed and pulled outside the room to move the exhaust gas flow rate adjustment valve 20 forward and backward in the horizontal exhaust gas passage 14b. The amount of protrusion of the exhaust gas into the combustion chamber 101 is adjusted, the opening area of the horizontal exhaust gas passage 14b at the opening is adjusted, and the amount of exhaust gas introduced into the combustion chamber 101 is adjusted. By pushing and pulling the operation rod 210, the exhaust gas flow rate adjustment valve 20 removes particulate matters such as silicon compounds adhering to the periphery of the opening 101a and scrapes various compounds such as the tar into the combustion chamber 101. It is the same as the exhaust gas flow rate adjusting valve 20 disclosed in Patent Document 2 in terms of dropping.

  As described above, the operation rod 210 according to the present invention and the operation rod 21 disclosed in Patent Document 2 are disposed in the opposite positions, so that the operation rod 210 according to the present invention can be used together with the exhaust gas flow rate adjustment valve 20. The exhaust gas is completely accommodated in the horizontal exhaust gas passage 14b, which is a passage for introducing exhaust gas into the combustion chamber 101, so that the operation rod 210 is not exposed to the high temperature of the combustion chamber 101, and heat deterioration and Not only can the thermal deformation be reduced and the service life can be greatly increased, but also the maintenance of the inside of the horizontal exhaust gas passage 14b, the exhaust gas flow rate adjusting valve 20 and the operating rod 210 is facilitated.

  As a result, the breakage of the operating rod 210 is greatly reduced, and the exhaust gas flow rate adjustment valve 20 can be smoothly advanced and retracted, and attached to the periphery of the opening that is the exhaust gas introduction port to the combustion chamber 101 of the horizontal exhaust gas passage 14b. Particulates such as silicon compounds and tar components accumulated on the inner surface of the horizontal exhaust gas passage 14b can be reliably discharged to the combustion chamber 101, and the amount of foreign matter falling into the carbonization furnace 2 is significantly reduced. Further, the occurrence of yarn breakage and fluff generation of the carbon fiber running in the carbonization furnace 2 can be reduced, and the carbonization process can be stabilized and high-quality carbon fiber can be obtained.

  The control mechanism (not shown) includes a processing unit and an interface unit (not shown), and the processing unit is electrically connected to the automatic mixing valve, the burner, and the thermometer via the interface unit. Based on the temperature information from the thermometer, the amount of fuel and air supplied to the burner required to set the combustion temperature in the combustion chamber 101 to the set temperature is calculated. It controls the flow rate of fuel and air in the mixing valve, ignition of the burner, extinguishing and the time.

  The processing unit may be realized by dedicated hardware, and is configured by a memory and a central processing unit (CPU), and a program for realizing the function of the processing unit is loaded into the memory. The function may be realized by executing the function. The control mechanism is connected with an input device such as a display touch panel, a switch panel, and a keyboard, and a display device such as a CRT and a liquid crystal display device as peripheral devices.

  Next, an exhaust gas treatment method from the carbonization furnace 2 using the carbonization furnace exhaust gas treatment apparatus 10 will be described. First, before introducing the exhaust gas from the carbonization furnace 2, the inside of the combustion chamber 101 is heated by a burner in advance so that the temperature in the combustion chamber 101 becomes 750 ° C. or higher.

  Next, the exhaust gas flow rate adjustment valve 20 and the air flow rate adjustment valve 103 provided in the air supply pipe 102 are opened, and exhaust gas and air are introduced into the combustion chamber 101 to start combustion of the exhaust gas. The exhaust gas once ignited continues to self-combust at a combustion temperature of 750 ° C. or higher in the combustion chamber 101 as long as the exhaust gas is stably introduced from the carbonization furnace 2.

  When the processing amount of the fiber immediately after the start of operation is small or due to a process trouble, the processing amount per time of the fiber to be carbonized in the carbonization furnace 2 decreases, and the amount of exhaust gas introduced into the combustion chamber 101 decreases. When it decreases, the combustion temperature in the combustion chamber 101 decreases. This decrease in temperature is detected by the control mechanism based on temperature information transmitted from the thermometer to the control mechanism as needed. When the temperature in the combustion chamber 101 decreases and approaches 750 ° C., the control mechanism adjusts the fuel and air automatic mixing valve to increase the flow rates of the fuel and air supplied to the burner. When the burner is extinguished, the burner is ignited and the combustion chamber 101 is heated. The exhaust gas burned in the combustion chamber 101 and rendered harmless is discharged from an exhaust port (not shown) and released into the atmosphere.

  The combustion temperature of the exhaust gas in the combustion chamber 101 is 750 ° C. or higher, preferably 800 to 900 ° C. If the combustion temperature of the exhaust gas is less than 750 ° C., decomposition products in the exhaust gas, particularly hydrogen cyanide, may not be completely burned and oxidized. On the other hand, even if the exhaust gas is burned at a temperature exceeding 900 ° C., the amount of fuel consumed may increase, and the deterioration of the refractory material in the combustion chamber 101 is only accelerated, which is not preferable. At this time, it is possible to prevent the temperature in the combustion chamber 101 from rising excessively by adjusting the flow rate of the exhaust gas to the combustion chamber 101 by operating the operation rod 210 attached to the exhaust gas flow rate adjustment valve 20. Is possible.

  In such an exhaust gas treatment method from a carbonization furnace, ignition and extinguishing of a burner provided so that the inside of the combustion chamber 101 can be heated is controlled, and an advance / retreat position of the exhaust gas flow rate adjustment valve 20 is adjusted. Thus, the exhaust gas can be efficiently burned while maintaining the combustion temperature in the combustion chamber 101 at 750 ° C. or higher. This makes it possible to completely treat silicon compounds adhering to the periphery of the opening of the horizontal exhaust gas passage 14b and toxic substances such as hydrogen cyanide in the exhaust gas, so that the fibers running in the carbonization furnace 2 are greatly broken and fluffed. Therefore, stable processability is ensured, and high-quality carbon fiber is obtained.

In the above description shown in FIG. 1, the first exhaust gas passage and the second exhaust gas passage are described as the vertical exhaust gas passage 14 a rising vertically upward and the horizontal exhaust gas passage 14 b extending horizontally from the vertical exhaust gas passage 14 a to the combustion chamber 101. However, the first exhaust gas passage and the second exhaust gas passage are not necessarily vertical or horizontal as described above. For example, as shown in FIG. 2, the second exhaust gas passage is provided to be inclined toward the combustion chamber 101. You can also. In this case, particulate matter such as a silicon compound or tar adhering to the periphery of the opening 101a is difficult to move to the first exhaust gas passage side, and particulate matter or tar scraped out by the exhaust gas flow rate adjustment valve 20 is used. Can be efficiently discharged into the combustion chamber 101.

DESCRIPTION OF SYMBOLS 1 Flame proofing furnace 2 Carbonization furnace 3 Heat exchanger 3a Heat exchange path 4 Heating external air supply path 5 Air volume detection means 6 Air volume adjustment valve 7 Control means (of temperature and air volume) 8 Heating external air supply opening 9 Hot air discharge opening 10 , 100 Carbonization furnace exhaust gas treatment device 10a, 101 Combustion chamber 101a Opening 10b, 102 Air supply pipe 10c, 103 Air flow control valve 11 Temperature detection means 12 Filter 13 First blower 14 Exhaust gas passage 14a Vertical exhaust gas passage (first exhaust gas) aisle)
14b Horizontal exhaust gas passage (second exhaust gas passage)
15 Second blower 19 Fuel pipe 20 Exhaust gas flow rate adjustment valve 21, 210 Operating rod 21a Tip operating section 211 Operating section F Precursor fiber bundle

Claims (2)

An apparatus for treating exhaust gas discharged from a carbonization furnace that carbonizes flameproof fibers in a high-temperature inert atmosphere,
A first exhaust gas passage rising from a carbonization furnace to the side of the combustion chamber;
A second exhaust gas passage that intersects the first exhaust gas passage and extends to the opening of the combustion chamber;
It is arranged in the second exhaust gas passage, moves forward and backward between the second exhaust gas passage and the combustion chamber across the opening in the passage, and adjusts the amount of protrusion into the combustion chamber to adjust the flow rate of the exhaust gas. An exhaust gas flow rate adjusting valve to be adjusted,
The exhaust gas flow rate adjusting valve extends from the back surface opposite to the opening across the first exhaust gas passage to the outside of the apparatus, and has a rod-shaped operation rod having an operation portion at an end portion on the back surface side. Having
Exhaust gas treatment equipment for carbonization furnace.   An exhaust gas treatment apparatus for a carbonization furnace, wherein the back surface of the exhaust gas flow rate adjusting valve is formed on a tapered surface inclined downward toward the rear.

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