JP2006263706A - Gas filtration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To certainly scrape off a carbon fiber captured by a filtration cloth. <P>SOLUTION: The gas filtration apparatus has a filtration chamber 20 formed with a carbon fiber discharge port 10 discharged with the carbon fiber and introduced with a gas containing the carbon fiber; a cylindrical filtration cloth 22 suspended in the filtration chamber 20 and capturing the carbon fiber in the gas to perform cleanliness of the gas; and a clean gas passage 30 continuously contacted with the filtration chamber 20 through the cylindrical filtration cloth 22 and leading out the cleaned gas. Further, the carbon fiber captured on a filtration surface of the cylindrical filtration cloth 22 is scraped off by a movement member 40 moved along the filtration surface of the cylindrical filtration cloth 22. The movement member 40 can be constituted as a basket-like member formed by a ring-like member, a rod-like member made to a spiral shape and a plurality of rod-like materials. Also, a brush can be preferably installed on the movement member 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas filtration device, and more particularly to a new technique for maintaining and improving dust collection efficiency by scraping off carbon fibers collected by a filter cloth.

  Carbon fiber is a well-known fibrous carbon, but in recent years, fine carbon fiber has attracted attention. There are several types of fine carbon fibers depending on the fiber diameter, and they are called vapor grown carbon fibers, carbon nanofibers, carbon nanotubes, and the like. Among them, carbon nanotubes have the finest fiber diameter of 100 nm or less, and their unique properties are expected to be widely applied to support catalysts such as nanoelectronic materials, composite materials, fuel cells, and gas absorption. Yes.

  The fine carbon fiber described above may use an inert gas such as hydrogen gas, nitrogen gas, or argon gas in the production process. When these gases and by-product hydrogen and hydrocarbon gas are used as a recycle gas, The process of removing the fine carbon fibers entrained in the case of treating as an exhaust gas is an indispensable process for improving the yield of the fine carbon fibers produced and purifying the gas.

  Conventionally, a gas filtration device is known as a device for removing dust contained in a gas and performing cleaning, and this gas filtration device has a particle size of a dust to be removed, a use environment, and the like. Various types are employed (see, for example, Patent Documents 1 and 2 below). General removal of dust and the like is performed by collecting dust and the like with a filter cloth installed in the apparatus, and removing the collected dust and the like.

  In addition, as a method for removing dust collected by the filter cloth, there are, for example, a so-called shaking type, backwashing type, and pulse jet type.

  The shaking type is a method in which dust is removed by shaking the filter cloth vigorously, and is the method that allows the strongest removal. However, in the shaking type, internal filtration is generally used, and when the adhering dust is entangled with strong tackiness and has a very small bulk specific gravity, it is difficult to remove from the filter cloth inner surface.

  In addition, the backwashing method is a method in which the filter cloth is deformed by creating a gas flow opposite to that during filtration, and dust attached to the surface of the filter cloth is peeled off and removed. Dust is required, and many auxiliary devices such as switching of filtration systems and backwash fan equipment are required for backwashing.

  Note that the pulse jet method is a method in which high-pressure air or the like is jetted and the filter cloth is swelled at a high speed so as to peel off adhering dust, so that relatively strong wiping off is possible. In general, a pulse is applied in the filtered state to perform the removal, but if the bulk density of the target dust is small and re-scattering occurs, the gas flow must be stopped to perform the removal.

JP-A-6-114222 (FIGS. 1 and 3) Japanese Patent Laid-Open No. 9-248413 (FIG. 1)

  However, in the production apparatus for fine carbon fiber, the fine carbon fiber to be produced contains 2 to 10% VM (tar content), the fibers are entangled with each other with a very strong adhesion force, and any of the conventional light weight specific gravity It was difficult to pay off even using the method.

  In addition, when a special gas is used in a system that circulates the filtered gas, it is mainly composed of hydrogen gas in an apparatus for producing fine carbon fibers, etc. According to the pulse jet method, the pulse jet requires hydrogen gas. However, it is difficult to wipe off with the mass of hydrogen in addition to the difficulty in equipment.

  In order to establish the conditions in the fine carbon fiber production part, it is necessary to keep the pressure fluctuation very small, and in the conventional method, it is difficult to apply due to the switching of the filtration chamber that occurs at the time of dropping and the pressure fluctuation caused by the pulse jet. there were.

  The present invention has been made in view of the above problems, and by providing a moving member that moves along the filtration surface of the filter cloth, the fine carbon fibers that adhere to the filter cloth with high adhesion can be reliably scraped. It is an object of the present invention to provide a gas filtration device that can be dropped and that can minimize pressure fluctuations caused by gas or air injection during filtration.

  The gas filtration device according to the present invention includes a filtration chamber in which an open end from which carbon fibers are discharged is formed and a gas containing carbon fibers is introduced, suspended in the filtration chamber, and traps carbon fibers in the gas. A gas filter device comprising: a cylindrical filter cloth that performs cleaning; and a clean gas passage that is connected to the filtration chamber via the cylindrical filter cloth and allows the flow of the purified gas, A moving member that moves along the filtration surface of the tubular filter cloth is provided, and the moving member scrapes off carbon fibers collected on the filtration surface of the tubular filter cloth.

  In the gas filtration device according to the present invention, the moving member is formed in a ring shape, and the ring-shaped ring circumferential surface is installed so as to be movable in the axial direction along the filtration surface of the tubular filter cloth. be able to.

  Further, in another gas filtration device according to the present invention, the moving member is formed to include a spiral rod-like member extending spirally in the axial direction of the cylindrical filter cloth, and the rod-like member is It can be installed so as to be rotatable and movable along the filtration surface of the cylindrical filter cloth.

  Furthermore, in another gas filtration device according to the present invention, the moving member is formed as a bowl-shaped member including a plurality of bars extending in the axial direction of the cylindrical filter cloth, and the bowl-shaped member is It can be installed so as to be rotatable and movable along the filtration surface of the cylindrical filter cloth.

  Further, in another gas filtration device according to the present invention, a spiral brush that extends spirally in the axial direction of the cylindrical filter cloth may be installed on the bowl-shaped member. .

  Furthermore, in the gas filtration device according to the present invention described above, it is preferable that a brush is further installed on the moving member.

  Furthermore, in the gas filtration device according to the present invention, it is preferable that an introduction duct for introducing the gas containing the carbon fiber is installed in the vicinity of the connection portion with the clean gas passage in the filtration chamber.

  In the above gas filtration apparatus, it is preferable that the cylindrical filter cloth is made of austenitic stainless steel fibers.

  The summary of the invention does not enumerate all necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to scrape off the fine carbon fiber adhering to a filter cloth with high adhesive force reliably, it becomes possible to provide the gas filtration apparatus which makes the pressure fluctuation which arises at the time of filtration as small as possible.

  In addition, when the filter cloth is formed of austenitic stainless steel fibers, it is possible to obtain a gas filtration device having excellent heat resistance and corrosion resistance of the filter cloth.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. In addition, in each embodiment described below, the case where the gas filtration apparatus which concerns on this invention is used in the manufacturing plant of a fine carbon fiber is illustrated and demonstrated. Gases that require a filtration step in a fine carbon fiber production plant include hydrogen gas, nitrogen gas, argon gas, and hydrocarbon gas by-produced in the production process, but this embodiment assumes hydrogen gas. The dust contained in such gas contains fine carbon fibers that contain tar and are entangled with each other and have extremely high adhesion. However, the following embodiments do not limit the invention according to each claim, and all combinations of features described in each embodiment are essential to the solution means of the invention. Not exclusively.

[First Embodiment]
FIG. 1 is a schematic diagram for explaining the overall configuration of the gas filtration device according to the first embodiment. Moreover, FIG. 2 is a figure which shows the detail of the code | symbol ((alpha)) part in FIG. 1, and is a figure for demonstrating the principal part of the moving member which the gas filtration apparatus which concerns on 1st Embodiment has.

  The gas filtration device according to the first embodiment has two chambers, a filtration chamber 20 and a clean gas passage 30, as main components. The filtration chamber 20 is a room having a carbon fiber outlet 10 below, and the carbon fiber outlet 10 can be connected to a carbon fiber recovery device or a carbon fiber recovery container (not shown). The carbon fiber scraped off is discharged and collected through the carbon fiber discharge port 10.

  The filtration chamber 20 is a chamber into which a gas containing carbon fiber is introduced. In the vicinity of the upper portion of the filtration chamber 20, an introduction duct 21 for introducing a gas containing carbon fiber is installed. A plurality of cylindrical filter cloths 22 are suspended in the filtration chamber 20, and the cylindrical filter cloth 22 collects carbon fibers in the gas introduced through the introduction duct 21, thereby purifying the gas. Will be performed. Although it is desirable to suspend a plurality of the tubular filter cloths 22 in order to improve the recovery efficiency of fine carbon fibers, even if a single filter cloth 22 is singular, the number of suspensions illustrated in FIG. 1 can be sufficiently exerted. It is not limited to.

  In addition, in order to maintain the outline shape of the cylindrical filter cloth 22, a holding member (not shown) having a cylindrical shape made of a punching metal having an aperture ratio of about 70% is provided. The tubular filter cloth 22 and the holding member are band-tightened with a predetermined interval to prevent the displacement of the tubular filter cloth 22 and the holding member due to the moving member 40.

  The clean gas passage 30 is a room connected to the upper part of the filtration chamber 20 via the cylindrical filter cloth 22, and the purified gas after the carbon fibers are collected by the cylindrical filter cloth 22 passes through the clean gas passage 30. It is space. The clean gas passage 30 is provided with a lead-out duct 31 for leading the purified gas, and the gas led through the lead-out duct 31 is reused as recovered hydrogen gas.

  The gas filtration device according to the first embodiment having the above main configuration is further provided with a moving member 40 that moves along the outer peripheral surface of the cylindrical filter cloth 22. As shown in more detail in FIG. 2, the moving member 40 is a member formed in a ring shape, and the inner surface side of the ring can move up and down in the axial direction along the outer peripheral surface of the cylindrical filter cloth 22. It is installed like that. The moving member 40 can be moved up and down by, for example, a cylinder mechanism installed above the clean gas passage 30. The mechanism illustrated in FIG. 1 is of a type in which a plurality of cylinders 42 respectively corresponding to the plurality of cylindrical filter cloths 22 are installed, and the drive shaft 41 of the cylinder 42 and the moving member 40 are connected. By driving the cylinder 42, the drive shaft 41 moves up and down, and the moving member 40 moves up and down with this movement. When the moving member 40 moves up and down along the outer peripheral surface of the tubular filter cloth 22, the carbon fibers collected on the surface of the tubular filter cloth 22 are scraped off.

  The configuration of the gas filtration device according to the first embodiment has been described above. Subsequently, the operation of the gas filtration device according to the first embodiment will be described. First, the gas containing carbon fiber is introduced into the filtration chamber 20 through the introduction duct 21 from the direction indicated by the arrow A. When the gas introduced into the filtration chamber 20 passes through the tubular filter cloth 22 suspended in the filtration chamber 20, the carbon fibers contained therein are separated and cleaned in the clean gas passage 30. Break into. The purified gas is led out in the direction of the arrow indicated by the symbol B through the lead-out duct 31, and is reused as recovered hydrogen gas.

  On the other hand, the carbon fibers attached to the surface of the cylindrical filter cloth 22 continue to adhere and accumulate on the cylindrical filter cloth 22 in accordance with the amount of gas passing, and gradually form a dust layer. If this dust layer accumulates more than a predetermined amount, the filtration performance of the cylindrical filter cloth 22 will be significantly reduced. Therefore, by driving the cylinder 42, the ring-shaped moving member 40 is moved up and down along the outer peripheral surface of the tubular filter cloth 22. By moving up and down in this way, the moving member 40 can scrape off the dust layer collected and deposited on the surface of the cylindrical filter cloth 22 on the inner surface side of the ring. By the scraping operation performed by the moving member 40, the filtration performance of the cylindrical filter cloth 22 is restored, and the operation of the gas filtration device can be continued well.

  Moreover, as a suitable point that the gas filtration device according to the first embodiment has, the introduction duct 21 for introducing the gas containing carbon fiber is near the upper portion of the filtration chamber 20 (with the clean gas passage 30). It is mentioned that it is installed in the vicinity of the connecting part). In the conventional gas filtration apparatus, the gas introduction duct 21 before cleaning is installed below the apparatus or in the vicinity of the carbon fiber discharge port 11 (see, for example, Patent Documents 1 and 2 above). However, when the gas introduction path before the cleaning and the dust discharge path are set close to each other as in the prior art, there is a problem in that it is impossible to efficiently collect the dust because the conductors cross each other. Therefore, in the gas filtration device according to the first embodiment, the introduction duct 21 that is the gas introduction path before cleaning and the carbon fiber discharge port 11 that is the dust discharge path are separated so that the respective conductors do not cross each other. By installing it in a new location, it was possible to recover carbon fiber more efficiently than in the prior art.

  Further, in order to realize better scraping off of the dust layer, for example, as shown in FIG. 3, it is possible to install a brush 43 on the ring inner surface side of the ring-shaped moving member 40. In addition to scraping off the dust layer only by the ring member, by adding the effect of scraping by the brush 43, the filtration performance of the cylindrical filter cloth 22 can be recovered more efficiently.

[Second Embodiment]
In the above-described first embodiment, the carbon fiber collected by the tubular filter cloth 22 is scraped by moving the moving member 40 formed in a ring shape up and down along the outer peripheral surface of the tubular filter cloth 22. A gas filtration device configured to drop is described. In the second embodiment, when the moving member installed along the axial direction of the cylindrical filter cloth 22 is rotated and moved, the carbon fibers collected by the cylindrical filter cloth 22 are scraped off. The gas filtration device will be described. In the following description, members that are the same as or similar to the members described in the first embodiment described above are assigned the same reference numerals, and descriptions thereof are omitted.

  FIG. 4 is a schematic diagram for explaining the overall configuration of the gas filtration device according to the second embodiment. FIG. 5 is a diagram illustrating details of the reference numeral (β) in FIG. 4, and is a diagram for explaining a main part of the moving member included in the gas filtration device according to the second embodiment.

  In the gas filtration device according to the second embodiment, the moving member 50 for scraping off the dust layer collected and deposited on the surface of the tubular filter cloth 22 is spirally formed in the axial direction of the tubular filter cloth 22. It was formed as a member having a spiral rod-like member 51 extending. The moving member 50 includes a spiral bar 51 and two end members 52 connected to both ends of the bar 51.

  For example, as shown in FIG. 4, the driving mechanism of the moving member 50 is formed with a gear on the outer peripheral surface of the end-supporting member 52 located at the upper end of the rod-shaped member 51, and a gear shaft 53 that meshes with the gear. Further, it can be realized by installing a motor 54 that is drivably connected to the gear shaft 53. Then, by performing rotation control of the motor 54, the moving member 50 can be rotated and moved. The spiral rod-shaped member 51 of the moving member 50 rotates along the outer peripheral surface of the cylindrical filter cloth 22 and has a time difference from the spiral action when viewed in the axial direction of the cylindrical filter cloth 22. Therefore, the dust layer can be effectively scraped off.

[Third Embodiment]
3rd Embodiment demonstrated below shows the modification of the moving member 50 which concerns on 2nd Embodiment. FIG. 6 is a diagram illustrating one form of the moving member 60 according to the third embodiment.

  In the second embodiment described above, the moving member 50 including the spiral bar 51 and the two end members 52 connected to both ends of the bar 51 has been described. On the other hand, the moving member 60 according to the third embodiment is connected to a plurality (three in FIG. 6) of rods 61 extending in the axial direction of the cylindrical filter cloth 22 and both ends of the plurality of rods 61. It is a member characterized in that it is formed as a bowl-shaped member by two end holding members 62. In the moving member 60 according to the third embodiment formed as a bowl-shaped member, a plurality of bar members 61 constituting the moving member 60 are rotatably installed along the outer peripheral surface of the tubular filter cloth 22. Yes. A plurality of bars 61 installed in this way play a role of scraping off the dust layer collected and deposited on the surface of the cylindrical filter cloth 22.

  As a modification of the moving member 60 according to the third embodiment, it is also possible to employ a moving member 70 in which brushes 63 are installed on a plurality of bar members 61 as shown in FIG. . In particular, in the case of the moving member 60 according to the third embodiment formed as a bowl-shaped member, only the inner side surfaces of the plurality of rod members 61 will scrape off the dust layer. Like the moving member 70 shown, it is preferable to install a rotatable brush 63 on the side facing the cylindrical filter cloth 22 and to install a bar 61 so as to surround the outside of the brush 63. With such a configuration, the brush 63 revolves while the brush 63 rotates, and thus the scraping of the dust layer is promoted by the synergistic effect of the brush 63 and the bar 61, and the cylindrical filter cloth Recovery of the filtration performance in 22 can be performed more efficiently.

  Furthermore, as another modification of the moving member 60 according to the third embodiment, as shown in FIG. 8, it is also preferable to install a spiral brush 64 on the moving member 60 formed as a bowl-shaped member. It is. According to the moving member 80 using the spiral brush 64, the time difference is scraped off by the spiral action, the scraping performance is improved by the brush action, and the continuous scraping effect is obtained by the action of the hook-like member. The filtration performance of the cylindrical filter cloth 22 can be further improved.

  As mentioned above, although preferred embodiment of this invention was described, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the embodiment.

  For example, it is possible to employ a moving member having a configuration in which the moving member 70 shown in FIG. 7 and the moving member 80 shown in FIG. 8 are combined. Further, the mechanism for driving the moving members 40, 50, 60, 70, 80 according to each embodiment is not limited to the one using the illustrated cylinder or the one driven by the motor, and any driving mechanism can be adopted. It is.

  Further, in each of the above-described embodiments, a so-called external filtration type gas filtration device in which the carbon fibers collected on the outer peripheral surface of the cylindrical filter cloth 22 are scraped off by the moving member 40 has been described (FIGS. 1 and 4). reference). However, the application of the present invention is not limited to such an outer surface filtration method, and can also be applied to an inner surface filtration method. That is, a cylindrical pipe cloth is used, and a holding member that is formed of a punching metal or the like having an opening ratio of about 70% is provided on the outer peripheral surface side of the cylindrical filter cloth, and is provided at a predetermined interval. The shape of the filter cloth is held by fixing it from the inside of the cylindrical filter cloth to the inside of the holding member with a spring band, and the moving member is movably installed on the inner peripheral surface side of the cylindrical filter cloth. And an internal filtration system is realizable by setting the flow of the gas containing carbon fiber to the reverse direction to the gas filtration apparatus illustrated in FIG. 1 or FIG. About selection of such a filtration system, what is necessary is just to employ | adopt a suitable thing suitably according to the characteristic of the gas, the dust, etc. to contain.

  It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

  In the above first to third embodiments, the cylindrical filter cloth 22 is preferably polyester, polypropylene, polytetrafluoroethylene, nylon and glass fiber, and more preferably for improving heat resistance and corrosion resistance. Examples include fibers of austenitic stainless steel.

  The fibers of this austenitic stainless steel are, in mass%, C: 0.15% or less, Si: 5.00% or less, Mn: 10.00% or less, P: 0.20% or less, S: 0 .15% or less, Ni: 3.50 to 28.00%, Cr: 15.00 to 26.00%, and further containing one or more kinds of Mo, Cu, N, Se, Nb and Ti as required The austenitic stainless steel fibers thus made can be used as the material for the cylindrical filter cloth.

  In the above-described components, in terms of mass%, C: 0.08% or less, Si: 1.00% or less, Mn: 2.50% or less, P: 0.045% or less, S: 0.030% or less When the C content is reduced, such as Ni: 7.00 to 15.00% and Cr: 16.00 to 20.00%, a filter cloth with more flexibility can be obtained. Furthermore, the filter cloth which was more excellent in heat resistance can be obtained by containing Mo in the range of 2.00 to 3.00%. The balance is Fe and impurities inevitably contained. JIS standard SUS304, SUS304L, SUS316, SUS316L, etc. are suitable as austenitic stainless steel fibers that satisfy these conditions.

When producing fine carbon fibers, exhaust gas is discharged. Although the temperature of this exhaust gas changes with the production | generation conditions of fine carbon fiber, it will be 100 to 400 degreeC. If an austenitic stainless steel fiber is used as the material of the tubular filter cloth 22, the function of the tubular filter cloth 22 can be maintained even when the temperature of the exhaust gas is as high as 400 ° C. It also has excellent corrosion resistance.

It is the schematic for demonstrating the whole structure of the gas filtration apparatus which concerns on 1st Embodiment. It is a figure which shows the detail of the code | symbol ((alpha)) part in FIG. 1, and is a figure for demonstrating the principal part of the moving member which the gas filtration apparatus which concerns on 1st Embodiment has. It is a figure which shows the modification of the moving member which the gas filtration apparatus which concerns on 1st Embodiment has. It is the schematic for demonstrating the whole structure of the gas filtration apparatus which concerns on 2nd Embodiment. It is a figure which shows the detail of the code | symbol ((beta)) part in FIG. 4, and is a figure for demonstrating the principal part of the moving member which the gas filtration apparatus which concerns on 2nd Embodiment has. It is a figure which illustrates one form of the moving member which concerns on 3rd Embodiment. It is a figure which shows the modification of the moving member which concerns on 3rd Embodiment. It is a figure which shows another modification of the moving member which concerns on 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Carbon fiber discharge port, 20 Filtration chamber, 21 Introduction duct, 22 Cylindrical filter cloth, 30 Clean gas passage, 31 Derivation duct, 40, 50, 60, 70, 80 Moving member, 41 Drive shaft, 42 Cylinder, 43, 63 Brush, 51 Bar-shaped member, 52, 62 End member, 53 Gear shaft, 54 Motor, 61 Bar, 64 Spiral brush.

Claims (8)

A filtration chamber in which an open end from which carbon fibers are discharged is formed and a gas containing carbon fibers is introduced;
A tubular filter cloth suspended in the filtration chamber and collecting carbon fibers in the gas and purifying the gas,
A gas filtration device having a clean gas passage connected to the filtration chamber via the cylindrical filter cloth and allowing the flow of the purified gas;
A gas filtration device comprising: a moving member that moves along a filtration surface of the tubular filter cloth, wherein the moving member scrapes off carbon fibers collected on the filtration surface of the tubular filter cloth. The gas filtration device according to claim 1, wherein
The moving member is formed in a ring shape,
The gas filtration device, wherein the ring-shaped ring peripheral surface is installed so as to be movable in the axial direction along the filtration surface of the cylindrical filter cloth. The gas filtration device according to claim 1, wherein
The moving member includes a spiral rod-like member extending spirally in the axial direction of the cylindrical filter cloth,
The gas filtration device, wherein the rod-shaped member is rotatably installed along a filtration surface of the cylindrical filter cloth. The gas filtration device according to claim 1, wherein
The moving member is formed as a bowl-shaped member including a plurality of bars extending in the axial direction of the cylindrical filter cloth,
The gas filter device, wherein the flange-shaped member is rotatably installed along the filtration surface of the cylindrical filter cloth. The gas filtration device according to claim 4, wherein
The gas filter according to claim 1, wherein a spiral brush extending in a spiral shape in the axial direction of the cylindrical filter cloth is installed on the bowl-shaped member. In the gas filtration device according to any one of claims 1 to 5,
The gas filtering device, wherein the moving member is further provided with a brush. In the gas filtration device according to any one of claims 1 to 6,
A gas filtration apparatus, wherein an introduction duct for introducing a gas containing the carbon fiber is installed in the vicinity of a connection portion with the clean gas passage in the filtration chamber. In the gas filtration device according to any one of claims 1 to 7,
The tubular filter cloth is made of austenitic stainless steel fibers, and is a gas filtration device.

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