JP4395050B2 - Exhaust gas treatment equipment - Google Patents

Description

  The present invention relates to an exhaust gas treatment apparatus, and more particularly to an exhaust gas treatment apparatus that is coupled to, for example, a vapor growth carbon fiber production apparatus and treats exhaust gas discharged from the vapor growth carbon fiber production apparatus.

  As an apparatus for producing fine vapor-grown carbon fiber, “equipped with a nozzle of a raw material supply means arranged at one end of a furnace core tube so that a carbon source gas and a catalytic metal source gas can be supplied into the furnace core tube. Reaction means, discharge means provided with a discharge pipe disposed in the furnace core tube so that the opening faces the tip opening of the nozzle, and an opening of the discharge pipe from the other end of the furnace core tube And a fine vapor growth carbon fiber production apparatus characterized by comprising a guide gas supply means for supplying a guide gas to be supplied to the exhaust pipe and then into the discharge pipe. A method for producing fine vapor-grown carbon fibers to be used has been proposed (see, for example, Patent Document 1).

  Further, “a vertical reaction means having a reaction region for generating a carbon fiber material by thermally decomposing a catalytic metal source and a carbon source gas supplied from the upper part of the vertical furnace core tube, and a carbon fiber generated in the reaction region” A discharge means having a discharge pipe that takes in the material from the opening and discharges it out of the vertical reaction means, and flows from the lower part of the vertical furnace core pipe to the opening of the discharge pipe, together with the carbon fiber material in the discharge pipe And a carbon fiber material manufacturing method using the carbon fiber material manufacturing apparatus (for example, a carbon fiber material manufacturing device characterized by comprising a guide gas supply means for supplying a guide gas distributed to , See Patent Document 2. Hereinafter, in this specification, the fine vapor growth carbon fiber production apparatus is referred to as a vapor growth carbon fiber production apparatus, and the fine vapor growth carbon fiber is simply referred to as carbon nanofiber. Or it may be referred to as CNT for short.).

  Although not described in the above document, the vapor-grown carbon fiber production apparatus is provided with a CNT separation unit, and the carbon nanotubes generated in the vapor-grown carbon fiber production apparatus by this CNT separation part. Carbon nanofibers are separated from the product gas containing the fibers. The exhaust gas after the carbon nanofibers are separated by the CNT separation unit is led out to the combustion furnace through the exhaust gas outlet pipe. The derived exhaust gas is incinerated in a combustion furnace.

  The exhaust gas contains carbon nanofibers that are actually not separated and separated even though the carbon nanofibers are separated at the CNT separation part, and further, unreacted carbon source gas and by-produced hydrocarbon gas, etc. And a tar-like product formed by a part of the combustible gas. The carbon nanofibers that are not completely removed from the product gas and remain in the exhaust gas are intertwined with each other in a complex manner, and the tar-like materials adhere to each other, so that the overall appearance is cotton-like. In addition, some carbon nanofibers may be formed into a long fibrous material in which a plurality of carbon nanofibers are bonded with tar or the like.

  Furthermore, small cotton-like materials made of carbon nanofibers may be joined together to form a larger cotton-like material. Conventionally, such a cotton-like material has adhered to the inner wall of the exhaust gas outlet pipe, thereby narrowing the effective flow diameter of the exhaust gas outlet pipe, and in some cases even clogged the exhaust gas outlet pipe. Thus, when the effective flow diameter of the exhaust gas outlet pipe is narrowed by the cotton-like material, or the exhaust gas outlet pipe is closed, the pressure in the piping system leading from the vapor growth carbon fiber production apparatus to the combustion furnace decreases, There was a risk of backfire that the fire of the combustion furnace ignites the combustible gas in the piping system.

  As described above, the vapor-grown carbon fiber production apparatus is connected to the incinerator and the exhaust gas outlet pipe, so when backfire occurs, the backfire is transmitted to the combustible gas in the exhaust pipe, There was a risk of explosion by reaching a vapor-grown carbon fiber production apparatus.

  Also, if the exhaust gas outlet pipe is closed or if the valve is closed in the exhaust gas outlet pipe, the pressure in the reaction pipe in the vapor growth carbon fiber production apparatus rises, and the pressure of the hydrogen gas supplied into the reaction pipe increases. Then, hydrogen gas is ejected from the reaction tube. Then, there is a serious danger that the ejected hydrogen gas is ignited and a fire or explosion of the entire apparatus occurs.

  When carbon nanofibers are produced in a reaction tube in a vapor growth carbon fiber production apparatus, the gas flow in the reaction tube is rectified, the temperature is made uniform, and the productivity and quality of the carbon nanofibers are improved. It is required to improve. Therefore, the occurrence of large pressure fluctuations in the reaction tube is a particularly serious problem affecting the productivity and quality of carbon nanofibers.

JP 2001-115342 A JP 2001-73231 A

  Therefore, the present invention is an exhaust gas treatment apparatus that can safely and stably treat exhaust gas without causing pressure fluctuations in a reaction tube in a vapor growth carbon fiber production apparatus in order to solve the conventional problems. The issue is to provide

As means for solving the above problems,
Claim 1 is a water storage tank for storing water and a carbon nanofiber-containing exhaust gas generated by a fluidized vapor phase method soaked in water so as to be introduced into the water in the water storage tank. has a notch formed by notched toward the axis direction from its tip, Ri Na fluctuation range of the pressure of the exhaust gas is able to form maintained substantially constant, the reaction in the vapor-grown carbon fiber production unit An exhaust gas treatment apparatus comprising an exhaust gas introduction pipe connected to a carbon nanofiber collection device that separates carbon nanofibers from a carbon nanofiber-containing gas discharged from a pipe,
Claim 2 is the exhaust gas treatment apparatus according to claim 1, wherein the fluctuation range of the pressure is at most ₂₀ mmH ₂ O,
A third aspect of the present invention is the exhaust gas treatment apparatus according to the first or second aspect, wherein the exhaust gas introduction pipe is provided with a plurality of through holes in an outer peripheral surface of a tip end immersed in the water storage tank.

  According to the present invention, since the tip of the exhaust gas introduction pipe is immersed in water in a water storage tank provided in the middle of the exhaust gas introduction pipe, the pressure fluctuation in the reaction tube in the vapor growth carbon fiber production apparatus The width can be reduced and the carbon nanofibers can be stably produced.

  In addition, since the tip of the exhaust gas introduction pipe is immersed, the exhaust gas treated by this exhaust gas treatment apparatus and burned in the incinerator and the exhaust gas sent from the reaction pipe in the vapor growth carbon fiber production apparatus are Divided by water in the water storage tank. Therefore, even if a backfire from the combustion furnace happens, the backfire is stopped by the water storage tank, and the backfire is prevented from reaching the vapor growth carbon fiber production apparatus.

In addition, when a large number of through holes are provided in the outer peripheral surface of the tip portion of the exhaust gas introduction pipe immersed in the water storage tank, compared to a case where a large number of through holes are not provided in the outer peripheral surface of the tip portion of the exhaust gas introduction pipe Since fine bubble-like exhaust gas is discharged into the water in the water storage tank, the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe is 20 mmH ₂ O at most. When the fluctuation range of the pressure of the exhaust gas in the exhaust gas introduction pipe is small as described above, the fluctuation range of the pressure in the reaction tube in the vapor growth carbon fiber production apparatus is also reduced, and the carbon nanofibers are manufactured more stably. be able to.

If a notch is formed at the tip of the exhaust gas introduction pipe, the notch is cut from the tip in the axial direction, the exhaust gas also enters the water in the water storage tank as bubbles from this notch. Go. When the amount of minute carbon nanofibers adhering to the edge of the notch when the exhaust gas bubbles circulate from the notch reaches a certain value, the lump of carbon nanofibers that have adhered to the exfoliation will peel off from the notch To do. In other words, since the fluctuation range of the pressure of the exhaust gas in the exhaust gas introduction pipe is 20 mmH ₂ O at most , the carbon nanofiber film adhering to the notch is peeled off as compared with the case where the entire notch is closed. The fluctuation range of the pressure in the reaction tube in the phase-grown carbon fiber production apparatus can be suppressed to be small, and as a result, the carbon nanofiber can be produced stably.

  Hereinafter, an exhaust gas treatment apparatus according to the present invention will be described with reference to FIG. The exhaust gas treatment device shown in FIG. 1 is an example, and the exhaust gas treatment device according to the present invention is not limited to the device shown in FIG.

  An exhaust gas treatment apparatus 1 shown in FIG. 1 includes a water storage tank 2, a gas outlet pipe 3, an exhaust gas inlet pipe 4, a water inlet path 5, and a water outlet path 6.

  The water storage tank 2 is formed to store water so as to maintain a predetermined water level.

  The material of the water storage tank 2 may be any material having hermeticity, pressure resistance and corrosion resistance. For example, metal such as stainless steel, aluminum, aluminum alloy and titanium alloy or polyethylene, polyvinyl chloride, poly Polymers such as vinylidene chloride, polystyrene, and acrylic resin can be exemplified, and among these, stainless steel or polyvinyl chloride is preferable. The shape and size of the water storage tank 2 are not particularly limited as long as the object of the present invention is achieved.

  As shown in FIG. 1, the water storage tank 2 is provided with a water introduction path 5, and the water lead-out path 6 has a predetermined water level in the water storage tank 2. To be fitted. The water introduction path 5 supplies water to the water storage tank 2 continuously, intermittently, or at a desired time. The water lead-out path 6 drains excess water in the water storage tank 2. In addition, this water storage tank 2 may be comprised so that the amount of water stored can be replaced | exchanged for fresh water after progress for a fixed time.

  In addition, tap water is usually used as the water, but depending on the case, it may be purified water obtained by purifying general waste water or seawater.

  The gas outlet pipe 3 has one end opening connected to a position higher than the water surface in the water storage tank 2 and the other end connected to a combustion furnace. The gas containing the combustible gas obtained by separating the object b is led out to the combustion furnace.

  The position where the one-end opening of the gas outlet pipe 3 is attached to the water storage tank 2 is not particularly limited as long as the position is higher than the water level of the water stored in the water storage tank 2. For example, the water storage tank Any position of the ceiling part or side wall part of the tank 2 may be sufficient.

  The other end opening of the gas outlet tube 3 is connected to a combustion furnace, and a combustible gas flows therethrough. Therefore, the material for forming the gas outlet tube 3 has heat resistance and corrosion resistance. The material is preferable, and examples thereof include stainless steel, copper alloy, aluminum alloy, magnesium alloy, and low melting point alloy. A suitable material is stainless steel. As the shape of the gas outlet pipe 3, a cylindrical shape is usually preferable.

  One end of the exhaust gas introduction pipe 4 is connected to a carbon nanofiber collecting device that separates the carbon nanofibers from the carbon nanofiber-containing gas discharged from the reaction tube in the vapor growth carbon fiber production apparatus. Further, the exhaust gas introduction pipe 4 is arranged so that its tip end is immersed in the water stored in the water storage tank 2, and the exhaust gas discharged from the carbon nanofiber collecting device is disposed in the water storage tank 2. It is formed to guide underwater. As shown in FIGS. 2 and 3, slits 7 and through-holes 8 that are notches are formed on the peripheral side surface of the tip opening of the exhaust gas introduction pipe 4.

  The size, shape, and material of the exhaust gas introduction pipe 4 are not particularly limited as long as the inner surface is smooth. For example, the size of the exhaust gas introduction pipe 4 is usually 5 to 20 cm in inner diameter. For example, as the shape of the exhaust gas introduction pipe 4, a cylindrical pipe can be usually mentioned. For example, as the material of the exhaust gas introduction pipe 4, usually, metals such as stainless steel, copper alloy, aluminum alloy, magnesium alloy and low melting point alloy, polymers such as polyethylene, polyvinyl chloride, polyvinylidene chloride, polystyrene and acrylic resin Or ceramics, and stainless steel is preferred.

  Examples of the shape of the through-hole 8 include a circle, an ellipse, a semicircle, a semi-elliptical, a fan, a triangle, and a quadrangle.

The size of the through hole 8 is not particularly limited as long as the fluctuation range of the pressure of the exhaust gas can be set to ₂₀ mmH ₂ O at most. For example, if the shape of the through hole 8 is circular, The diameter is preferably 20 to 30 mm, and if it is a quadrangle, a square having a side of 2.5 to 25 mm is preferable. If the diameter of the through hole 8 is smaller than the lower limit value, there is a risk of clogging due to minute carbon nanofibers contained in the exhaust gas. If the diameter of the through hole 8 is larger than the upper limit value, the exhaust gas is introduced. There is a tendency that the fluctuation range of the pressure of the exhaust gas flowing through the pipe 4 increases.

The through hole 8 is appropriately determined according to the inner diameter of the exhaust gas introduction pipe 4, the diameter of the through hole 8, and the like so that the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 becomes small. In the case where the inner diameter of the exhaust gas introduction pipe 4 is in the inner diameter range and the diameter of the through-hole 8 is in the range, the exhaust gas introduction pipe 4 is formed to be 0.1 to 15 pieces / cm ^2. preferable. If the number of the through holes 8 is less than the lower limit value, the amount of exhaust gas discharged from the tip opening of the exhaust gas introduction pipe 4 increases, and the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 increases. there is a possibility.

  Thus, by forming the through-hole 8, the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 when introducing the exhaust gas into water can be reduced. When the through-hole 8 is not provided on the outer peripheral surface of the distal end portion of the exhaust gas introduction pipe 4, the exhaust gas is discharged as large bubbles a from the front end opening of the exhaust gas introduction pipe 4. Then, every time exhaust gas is discharged from the tip opening of the exhaust gas introduction pipe 4, the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 becomes large. Compared to the conventional exhaust gas outlet pipe having a peripheral side surface that does not have a through hole in this way, the exhaust gas introduction pipe 4 provided with the through hole 8 on the peripheral side surface of the tip portion does not increase the fluctuation range of the pressure in the exhaust gas. It ’s a big breakthrough.

As described above, the through hole 8 is provided such that the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 is maintained at 1 to ₂₀ mmH ₂ O. Accordingly, since the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 does not increase due to the formation of the through-hole 8, the fluctuation range of the pressure in the reaction tube in the vapor growth carbon fiber manufacturing apparatus for forming the carbon nanofibers. Can also be kept stable. Therefore, the vapor growth carbon fiber can be produced at a stable pressure in the reaction tube.

  As the shape of the slit 7 formed on the peripheral side surface of the exhaust gas introduction pipe 4, as shown in FIG. 2, an inverted V-shape as a shape projected on a plane can be exemplified.

  The inverted V-shape is triangular when a slit 7 cut out in the axial direction from the tip of the exhaust gas introduction pipe 4 immersed in the water storage tank is projected onto a plane. It is a shape that makes. The base of this triangle is formed by the leading edge of the exhaust gas introduction pipe 4. The apex of the triangle is on the outer peripheral surface of the tip of the exhaust gas introduction pipe 4.

  As shown in FIG. 2, the apex angle in the triangular slit 7 is preferably 1 to 20 degrees, and the axial length from the front edge of the exhaust gas introduction pipe 4 to the apex is 5 to 20 cm. Is preferred.

  When the triangular slit 7 having such an acute apex angle is formed, the exhaust gas is bubbled from the slit 7 at the tip of the exhaust gas introduction pipe 4 immersed in water and discharged into the water. The fine carbon nanofibers adhere to the vicinity of the apex portion of the slit 7, but the carbon nanofibers adhered by the exhaust gas pressure are peeled off from the slit 7 before the entire slit 7 is blocked by the carbon nanofibers. Become so.

  Therefore, the carbon nanofibers adhering so as to block the entire slit 7 do not peel from the slit 7 at once, so that the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 does not become so large.

  In order to better maintain the fluctuation range of the pressure of the exhaust gas flowing through the exhaust gas introduction pipe 4 within the above-described range, a gas pressure sensor is provided in the exhaust gas introduction pipe 4 and is detected by the gas pressure sensor. It is also possible to form the tip of the exhaust gas introduction pipe 4 so as to be able to move up and down with respect to the water surface in accordance with the pressure of the exhaust gas. The reason is as follows.

On the other hand, flow amount of exhaust gas that circulates the exhaust gas inlet tube 4 is usually preferable is 6~120m ³ / time, and more preferably from 12~60m ³ / time.

  When exhaust gas is discharged into the water from the exhaust gas introduction pipe 4 that immerses its tip in water stored in the water storage tank 2, as shown in FIG. 8, carbon nanofibers adhere to the slits 7 over time. To go. As the carbon nanofiber film 20 is formed by the attachment of the carbon nanofibers, the slit 7 is narrowed, whereby the bubble discharge position in the slit 7 is lowered from the top of the slit 7 to the lower end of the attachment range of the carbon nanofibers.

Then, the pressure of the exhaust gas in the exhaust gas introduction pipe 4 when the exhaust gas bubbles are discharged from the apex portion of the slit 7 is slightly larger than h ₁ mmH ₂ O, and the carbon nanofiber film 20 is formed in the slit 7. In this case, the pressure of the exhaust gas in the exhaust gas introduction pipe 4 is slightly higher than that of h ₂ mmH ₂ O. When the carbon nanofiber film 20 is peeled off from the slit 7, the pressure of the exhaust gas in the exhaust gas introduction tube 4 decreases from h ₂ mmH ₂ O to h ₁ mmH ₂ O when the exhaust gas introduction tube 4 is fixed. .

  Although this pressure drop may be a small value, the goal is to achieve carbon nanofiber production in the reaction tube under a constant pressure while avoiding pressure fluctuations in the reaction tube in the vapor growth carbon fiber production equipment as much as possible. In this case, it is preferable that the pressure drop is as close to zero as possible.

Therefore, a pressure sensor 21 is provided in the exhaust gas introduction pipe 4, and is formed by adhering to the slit 7 so that the pressure of the exhaust gas detected by the pressure sensor 21 is maintained at, for example, the h ₁ mmH ₂ O. Depending on the degree of the carbon nanofiber film 20, the exhaust pipe drive means 22 raises the tip of the exhaust gas introduction pipe 4, and the tip of the exhaust gas introduction pipe 4 is moved at the moment when the carbon nanofiber film 20 is detached from the slit 7. It is lowered so that the apex of the slit 7 is at the position h ₁ from the water surface.

  If it does so, the fluctuation range of the pressure of the exhaust gas which exists in the inside of the exhaust gas introduction pipe 4 can be eliminated. In addition, in FIG. 8, although the through-hole is not displayed on the outer peripheral surface of the exhaust gas introduction pipe 4, the through-hole shall be opened.

  As shown in FIG. 2, if the slit 7 and the through hole 8 are provided on the outer peripheral surface of the exhaust gas introduction pipe 4, the exhaust gas is discharged in the form of bubbles into the water through the through hole 8 and the slit 7. Going to be. In this case, although the reason is not clear, the minute carbon nanofibers contained in the exhaust gas are discharged into the water together with the exhaust gas preferentially from the slit 7 rather than the through-hole 8. Therefore, the clogging of the through-hole 8 is prevented by the formation of the slit 7, and the carbon nanofibers locked to the slit 7 are detached due to the pressure of the exhaust gas. Is suppressed as much as possible.

  Therefore, the pressure fluctuation in the reaction tube in the vapor growth carbon fiber production apparatus can be suppressed as much as possible, and carbon nanofibers can be produced under stable reaction conditions.

  The through holes and notches are not limited to the through holes and slits of the form shown in FIG. 2, and examples thereof include through holes and notches as shown in FIGS.

  Further, the exhaust gas introduction pipe 4A shown in FIGS. 4 and 5 has a mesh 8A formed at the tip thereof and four slits 7A whose upper part is semicircular. In the exhaust gas introduction pipe 4A shown in FIGS. 4 and 5, the wire mesh formed by the mesh 8A corresponds to the through hole.

  An exhaust gas introduction pipe 4B shown in FIG. 6 shows another example of a notch. The cutout portion in the exhaust gas introduction pipe 4B shown in FIG. 6 is a slit 7B that is vertically cut inward along the axial direction from the end edge of the exhaust gas introduction pipe 4B so as to be rectangular when projected onto a plane. is there. Two slits 7B are formed at positions opposed to the tip of the exhaust gas introduction pipe 4B. The number of slits 7B formed is not limited to two, and may be three or more. In FIG. 6, illustration of the through hole is omitted.

  The notch shown in FIG. 7 is a slit 7C formed in a substantially rectangular shape with one end rounded with respect to the slit 7B shown in FIG.

  Next, the operation of the exhaust gas treatment apparatus 1 which is an example of the present invention will be described.

  Carbon nanofibers generated in a reaction tube in a vapor growth carbon fiber production apparatus (not shown) are collected by a collector provided in the vapor growth carbon fiber production apparatus. Although the carbon nanofibers are collected by the collector, the exhaust gas discharged from the collector still contains some carbon nanofibers. The exhaust gas discharged from this collector is usually divided into two systems. In one system, it is returned to the vicinity of the outlet of the product gas suction pipe provided in the lower part of the reaction pipe by the gas circulation path. In another system, the exhaust gas is introduced into the exhaust gas treatment device 1 through the exhaust gas introduction pipe 4 arranged on the upstream side where the exhaust gas flows.

  Exhaust gas is discharged into the water stored in the water storage tank 2 through the exhaust gas introduction pipe 4. In the exhaust gas introduction pipe 4, exhaust gas is discharged into the water in the form of bubbles from a large number of through holes 8 formed on the outer peripheral surface of the tip part immersed in the water storage tank 2, and at the tip part of the exhaust gas introduction pipe 4. Exhaust gas is also released into the water in the form of bubbles from the slit 7 provided. When the exhaust gas is released into the water in the form of bubbles, removal of tar and the like contained in the exhaust gas is also performed. Thus, by removing tar or the like, for example, it is possible to prevent the carbon nanofibers that have become agglomerated from adhering to the tube wall of the exhaust gas introduction tube 4.

  This exhaust gas contains carbon nanofibers not collected by the collector. Exhaust gas bubbles are discharged into the water from the through holes 8 and the slits 7, but since the edge length of one slit 7 is usually longer than the circumferential length of one through hole 8, The amount is larger than the amount of bubbles released from the through hole 8.

  Therefore, rather than the through-hole 8 being blocked by the carbon nanofiber in the exhaust gas, as shown in FIG. 8, the carbon nanofiber adheres to the edge of the slit 7 near the apex of the triangular slit 7, The amount of adhesion increases. When the amount of carbon nanofiber attached to the slit 7 reaches a certain amount, the carbon nanofiber film attached to the slit 7 is detached from the slit 7 due to the pressure of the exhaust gas in the exhaust gas introduction pipe 4.

  Even if the carbon nanofiber film is detached from the slit 7 while the amount of the carbon nanofiber film 20 is small, the fluctuation range of the pressure in the exhaust gas introduction pipe 4 is small. Therefore, the small pressure fluctuation in the exhaust gas introduction pipe 4 due to the exhaust gas being discharged into the water from the exhaust gas introduction pipe 4 causes a very small pressure fluctuation in the reaction tube in the vapor growth carbon fiber production apparatus. Therefore, carbon nanofibers in the reaction tube can be produced in a stable pressure atmosphere.

  Further, the bubbles of the exhaust gas discharged into the water storage tank 2 are led out to the incinerator (not shown) from the gas outlet pipe 3 arranged on the downstream side where the exhaust gas flows. The exhaust gas is incinerated in the incinerator. Even if the pressure in the gas lead-out pipe 3 decreases and the incinerator causes a backfire, the water storage tank 2 disconnects the system including the gas circulation path and the reaction pipe in the vapor growth carbon fiber production apparatus from the incinerator. Therefore, the backfire does not reach the reaction tube in the vapor growth carbon fiber production apparatus.

  Furthermore, since the exhaust gas introduction pipe 4 is immersed in the water storage tank 2, all solid components such as carbon nanofibers contained in the exhaust gas from the exhaust gas introduction pipe 4 are removed in the water storage tank 2. It becomes. Therefore, the carbon nanofibers that have not been collected in the exhaust gas outlet pipe as in the conventional case do not accumulate, so that the exhaust gas outlet pipe 3 is not blocked.

  Although an example of the present invention has been described above, the exhaust gas treatment apparatus according to the present invention is conventionally known, for example, a vapor growth carbon fiber production apparatus described in Patent Document 1 and the like, and a carbon fiber material production described in Patent Document 2 and the like. The exhaust gas containing carbon nanofibers that are combined with the apparatus and discharged from these manufacturing apparatuses can be treated.

FIG. 1 is an explanatory view showing an example of an exhaust gas treatment apparatus according to the present invention. FIG. 2 is a side view showing an example of a discharge pipe having a through hole and a slit. FIG. 3 is a bottom view of the discharge pipe shown in FIG. FIG. 4 is a side view showing another example of a discharge pipe having a through hole and a slit. FIG. 5 is a bottom view of the discharge pipe shown in FIG. FIG. 6 is a diagram illustrating another example of a slit included in the discharge pipe. FIG. 7 is a diagram illustrating another example of a slit included in the discharge pipe. FIG. 8 is an explanatory view showing a state where the tip of the discharge pipe is immersed in the water in the water storage tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust gas processing apparatus 2 Water storage tank 3 Gas outlet pipe 4, 4A, 4B Exhaust gas outlet pipe 5 Water introduction path 6 Water outlet path 7, 7B, 7C Slit 8 Through-hole 20 Carbon nanofiber membrane 21 Pressure sensor 22 Exhaust pipe drive means a Bubble b Cotton

Claims (3)

A water storage tank for storing water and a carbon nanofiber-containing exhaust gas generated by a fluidized gas phase method are immersed in water so as to be introduced into the water in the water storage tank, and the axis line from the tip to the outer peripheral surface of the tip has a notch formed by notched toward, Ri Na is formed so as to be able to maintain a substantially constant fluctuation range of the pressure of the exhaust gas is discharged from the reaction tube in the vapor-grown carbon fiber production unit An exhaust gas treatment apparatus comprising: an exhaust gas introduction pipe connected to a carbon nanofiber collecting device for separating carbon nanofibers from a carbon nanofiber-containing gas . The exhaust gas treatment apparatus according to claim 1, wherein the fluctuation range of the pressure is at most ₂₀ mmH ₂ O.   The exhaust gas treatment apparatus according to claim 1 or 2, wherein the exhaust gas introduction pipe is formed with a plurality of through holes in an outer peripheral surface of a tip end immersed in the water storage tank.

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