JP2010240571A - Filter unit and gas cleaning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter unit capable of increasing the pressure resistance of a filter, suppressing the enlargement of an apparatus and prolonging the service life of the filter, and a gas cleaning system using the same. <P>SOLUTION: The filter unit 2 removes a foreign matter D contained in a raw gas DS by a filter module 10, and is provided with a filter case 12 storing the filter module 10. The filter case 12 has an introducing port 14 for introducing the raw gas DS to the filter module 10 formed at the lower part and a lead-out port 16 for leading out a cleaned gas CG which has passed through the filter module 10 formed at the upper part. The filter module 10 has many hollow fiber membranes 20 extending in the vertical direction inside a cartridge 22, the upper end part 20a of the hollow fiber membrane 20 is a fixed end fixed to the cartridge 22 and the lower end part 20b is a free end. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a filter unit that removes dust in a gas and a gas purification system using the same in a passage through which a gas flows, such as a gas pipe.

  For example, in a gas flow passage such as a gas pipe, in order to remove dust such as iron rust generated from aged pipes and earth and sand mixed during piping work, the opening through which the gas flows is about 1 mm. Generally, it is common to provide a metal strainer, collect dust in the gas pipe, and remove dust from the gas.

  However, in the purification system using the metal strainer as described above, only relatively large foreign matters can be removed. For example, in the case of gas piping, relatively fine dust adheres to the gear inside the gas meter. There is a problem of causing clogging. On the other hand, if a resin pleated filter is used to collect fine dust while maintaining the gas flow rate, the pressure loss increases and the filter frequently clogs. In order to prevent damage, it is necessary to constantly monitor the minute differential pressure on the primary and secondary sides of the filter with a micro differential pressure gauge, and the filter area must be larger than the gas flow rate passing through the filter. . As a result, the system becomes complicated and large, and the initial cost for introducing the system increases. Further, since the filter is large and has a short life, it must be frequently replaced, and the maintenance cost is high.

  The present invention has been made in view of the above problems, and provides a filter unit capable of increasing the pressure resistance of a filter, suppressing an increase in the size of the apparatus, and extending the life of the filter, and a gas purification system using the same. It is an object.

  In order to achieve the above object, a filter unit according to the present invention is a filter unit that removes foreign matter contained in a gas by a filter module, and includes a filter case that houses the filter module, and the filter case includes: An inlet for introducing the gas into the filter module is formed in the lower part, and an outlet for extracting the gas that has passed through the filter module is formed in the upper part. The filter module has a number of hollow fibers extending vertically in the cartridge. It has a membrane, the upper end of the hollow fiber membrane is a fixed end fixed to the cartridge, and the lower end is a free end.

  According to this configuration, since the hollow fiber membrane is used as the filter module, the pressure resistance of the filter module is improved. By increasing the differential pressure between the primary side and the secondary side of the filter, the flow rate is increased. The filtration area can be small, and as a result, the filter unit can be miniaturized. In addition, since the lower end of the hollow fiber membrane is a free end, the removed foreign matter falls down when the free end swings due to the flow of gas, so that the filter module can be prevented from being clogged. As a result, the life of the filter module is prolonged.

  In this invention, it is preferable to have the impeller which turns the gas introduce | transduced from the said inlet in the lower part in the said filter case. According to this configuration, gas is swirled by the impeller to promote the swinging of the hollow fiber membrane, so that foreign matters are more likely to fall and the life of the filter module can be extended.

  The impeller is preferably provided in a stopper that is disposed below the filter module and prevents the filter module from dropping. According to this configuration, since another member for the impeller is not necessary, the number of parts is not increased.

  Furthermore, it is preferable that the filter module is in electrical contact with a filter case made of a conductive material. According to this configuration, the static electricity generated by the friction of the hollow fiber membrane is released to the filter case serving as the ground through the filter case, so that foreign matters attached to the hollow fiber membrane can be more easily dropped.

  In the present invention, the pore diameter of the hollow fiber membrane is preferably 2 μm or more. If it is 2 μm or less, the pressure loss increases and the filtration area increases, but if it is 2 μm or more, the filtration area can be suppressed and the filter unit can be downsized.

  The gas purification system according to the present invention is a gas purification system using the above-described filter unit of the present invention, and includes backwashing means for backwashing the filter module with the gas introduced into the filter unit. According to this configuration, the foreign matter adhering to the filter module is removed by the backwashing means, so that the life of the filter module can be extended.

  According to the filter unit of the present invention, the hollow fiber membrane is used as the filter module for removing foreign substances contained in the gas, so that the pressure resistance of the filter module is improved. As a result, the filter unit can be reduced in size. Further, since the lower end portion of the hollow fiber membrane is a free end, the removed foreign matter falls down, so that the filter module can be prevented from being clogged, and as a result, the life of the filter module is prolonged. In addition, according to the gas purification system of the present invention, foreign matters attached to the filter module are removed by backwashing the filter module, so that the life of the filter module can be extended.

1 is a system diagram of a gas purification system according to a first embodiment of the present invention. It is the partially broken side view of the filter module of a gas purification system same as the above. It is a top view of the stopper of a gas purification system same as the above. It is a perspective view of the hollow fiber membrane of a filter module same as the above. It is a schematic system diagram of the gas purification system which concerns on 2nd Embodiment of this invention. It is a schematic system diagram of the gas purification system which concerns on 3rd Embodiment of this invention. It is a systematic diagram at the time of backflow washing | cleaning of a gas purification system same as the above. It is a perspective view of the hollow fiber membrane of the filter module of a system same as the above. It is a schematic systematic diagram of the gas purification system which concerns on 4th Embodiment of this invention. It is a systematic diagram when backwashing the 1st filter unit of a system same as the above. It is a systematic diagram when backwashing the 2nd filter unit of a system same as the above.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing a gas purification system according to the first embodiment of the present invention. The gas purification system 1 includes a filter unit 2 that removes foreign matter D (FIG. 4) contained in the gas, and an introduction passage that introduces gas containing the foreign matter D into the filter unit 2 (hereinafter referred to as “original gas DG”). 4, a lead-out passage 6 for leading the gas from which the foreign matter D has been removed by the filter unit 2 (hereinafter referred to as “purified gas CG”), and a dust box 8 positioned below the filter unit 2. The introduction passage 4 and the lead-out passage 6 are made of pipes. First to third on-off valves (in the vicinity of the filter unit 2 in the lead-in passage 4, near the filter unit 2 in the lead-out passage 6, and just before the dust box 8, respectively) ON-OFF valves) V1, V2, and V3 are provided.

  A T-shaped connection pipe 5 having three connection ports 51 to 53 is provided between the introduction passage 4 and the filter unit 2, more specifically, between the first on-off valve V 1 and the filter unit 2. The filter unit 2 is connected to one 51 (upper side in FIG. 1) of the first and second connection ports 51, 52 facing each other of the connecting pipe 5, and the dust box 8 is connected to the other 52 (lower side in FIG. 1). Are connected via a third valve V3. The first on-off valve V <b> 1 is connected to a third connection port 53 that opens in a direction orthogonal to a line connecting the centers of the first and second connection ports 51 and 52.

  The filter unit 2 includes three filter modules 10 that remove foreign matter D and a single cylindrical filter case 12 that houses the three filter modules 10. The filter case 12 is made of a conductive material, for example, steel, and an introduction port 14 for introducing the raw gas DG into the filter module 10 is formed in the lower part thereof, and the purified gas CG passing through the filter module 10 is led out to the upper peripheral wall. A lead-out port 16 is formed. An inlet passage 15 having a passage area smaller than that of the case main body portion in which the filter module 10 is housed in the filter case 12 is formed on the downstream side of the introduction port 14. The introduction passage 4 and the lead-out passage 6 are connected to the introduction port 14 and the lead-out port 16, respectively. An opening 18 is formed at the upper part of the filter unit 2 so that the filter module 10 can be replaced. The opening 18 is closed by a lid 19 that is detachably attached to the filter unit 2.

  As shown in FIG. 2, each filter module 10 is one in which a number of hollow fiber membranes 20 extending in the vertical direction are accommodated in a hollow cylindrical cartridge 22 whose axis is directed in the vertical direction. In this embodiment, the cartridge 22 is made of resin, but is not limited to this. The cartridge 22 is opened at the lower end portion to form an opening 22a toward the introduction port 14 (FIG. 1) of the filter unit 2, and gas can be introduced into the inside through the opening 22a. In addition, a plurality of gas introduction holes 22c are formed in the peripheral wall 22b, and gas is also introduced into the inside from here. A shoulder portion 22d is formed on the upper portion of the cartridge 22, and a mouth portion 22e having a diameter smaller than that of the peripheral wall 22b is continuously provided concentrically with the peripheral wall 22b. A sealing member 23 such as an O-ring is provided on the outer periphery of the mouth portion 22e. As shown in FIG. 1, the upper portion of the filter case 12, specifically, with the mouth portion 22e opening upward, The filter module 10 is supported by the filter case 12 by fitting the opening 22e to the module mounting member 21 provided slightly below the outlet 16.

  The filter case 12 has a stopper 28 that is disposed below the filter module 10 and prevents the filter module 10 from dropping. The stopper 28 is made of a conductive material, for example, steel. As shown in FIG. 3, the stopper 28 includes three impellers 30 which are fixed blades for turning the raw gas DG from the inlet 14 around the vertical axis. Is formed. More specifically, three impellers 30 are formed directly below each of the three filter modules 10 shown in FIG. The impeller 30 is made of a plate material. The blade surfaces 30a and 30b of the impeller 30 have a plate surface parallel to the flow direction F of the raw gas DG, and the plate surface of the impeller 30 is orthogonal to the flow direction F of the raw gas DG. In this way, a strip-shaped plate material is twisted by 180 °.

  As shown in FIG. 2, a ground piece 22 f made of a conductive material such as a flexible metal plate or metal is attached to the peripheral wall 22 b of the filter module 10 by a screw body 22 g, and this ground piece 22 f is attached to the stopper 28. In contact (FIG. 1), the filter module 10 is indirectly brought into electrical contact with the filter case 12. The ground piece 22f may be in direct contact with the filter case 12. The number of impellers 30 is not limited to three. For example, one impeller 30 may be provided in the hollow portion of the filter module 10. The impeller 30 only needs to have a shape that causes turbulent flow in the fluid passing through the impeller 30, and is not limited to the shape of FIG. In the present embodiment, the impeller 30 is provided in the stopper 28, but may be provided in the inlet passage 15 (FIG. 1) of the filter module 10. In that case, the number of impellers 30 can be reduced as compared with the present embodiment.

  The hollow fiber membrane 20 forms a fixed end in which the upper end portion 20 a is fixed to the cartridge 22, and the lower end portion 20 b forms a free end that is not fixed to the cartridge 22. Specifically, at the upper end portion 20a of the hollow fiber membrane 20, a large number of hollow fiber membranes 20 are bundled, and the hollow fiber membranes 20 and 20 are fixed by a fixing member 24 made of an adhesive resin such as an epoxy resin. The fixing member 24 is fitted to the inner periphery of the cartridge 22 near the shoulder 22d. The upper end portion 20a passes through the fixing member 24 and opens upward. In the lower end portion 20b, as shown in FIG. 4, the open end of the hollow portion 20c of each hollow fiber membrane 20 is closed by a sealing member 26 made of a resin such as an epoxy resin. The lower ends 20b, 20b and the lower end 20b and the cartridge 22 are not fixed to each other.

  In this embodiment, the hollow fiber membrane 20 is made of polysulfone (PS) coated polyvinyl alcohol (PVA), but is not limited to this, and the hollow fiber membrane 20 is made of a hollow fiber having an outer diameter d1 of 1.2 mm. Although the pore diameter d2 of the membrane is 2.5 μm, neither the outer diameter d1 of the hollow fiber nor the pore diameter d2 of the membrane is limited to this. The pore diameter d2 of the membrane is preferably 1 to 10 μm, and more preferably 2 to 7 μm.

  The hollow fiber membrane 20 is an external pressure type filtration membrane. That is, the raw gas DG introduced into the cartridge from the inlet 14 (FIG. 1) of the filter case 12 through the opening 22a at the lower end of the cartridge 22 and the gas introduction hole 22c passes through the outer wall 20d of the hollow fiber membrane 20. Then, it enters the hollow portion 20c. At that time, the foreign matter D larger than the hole diameter d2 of the membrane cannot pass through the outer wall 20d and adheres to the outer wall surface. Since the lower end portion 20b of the hollow fiber membrane 20 is closed, the purified gas CG that has entered the hollow portion 20c flows toward the upper end portion 20a and is introduced into the filter case 12 via the mouth portion 22e of the cartridge 22. Derived from the outlet 16 (FIG. 1). The foreign matter D adhering to the outer wall 20d of the hollow fiber membrane 20 falls and accumulates on the upper side of the third on-off valve V3 (FIG. 1) in front of the dust box 8, and opens the third on-off valve V3 at an appropriate timing. As a result, the accumulated foreign matter D is collected in the dust box 8.

  In order to remove the foreign matter D remaining on the hollow fiber membrane 20 without falling naturally, the first and second on-off valves V1 and V2 in FIG. 1 are closed, the lid 19 of the filter unit 2 is removed, and the filter By removing the filter module 10 from the case 12 and applying a physical impact by tapping the filter module 10 or the like, the foreign matter D is removed from the hollow fiber membrane 20. Thereafter, the filter module 10 can be returned to the filter case 12, the lid 19 is attached, and the first and second on-off valves V 1, V 2 can be opened for reuse. By repeatedly using the hollow fiber membrane 20 in this manner, the life of the filter module 10 can be extended.

  In the above configuration, since the hollow fiber membrane 20 is used as the filter module 10, the pressure resistance of the filter module 10 is improved. By doing so, the filtration area is small, and as a result, the filter unit 2 can be miniaturized. Further, since the lower end portion 20b of the hollow fiber membrane 20 is a free end, the free end is swung by the flow of the raw gas DG so that the removed foreign matter D falls down. Clogging can be prevented, and as a result, the life of the filter module 10 is prolonged.

  Furthermore, since the impeller 30 for turning the gas DS introduced from the introduction port 14 is provided in the lower part of the filter case 12, the hollow fiber membrane 20 is swung by turning the raw gas DS by the impeller 30, whereby the foreign matter D Can be more easily removed, clogging of the filter module 10 can be suppressed, and the life can be extended. By providing the impeller 30 on the stopper 28, the impeller 30 can be easily formed on the filter case 12. Further, since the filter case 12 and the stopper 28 are made of a conductive material and the filter module 10 is in contact with the stopper 28 via the ground piece 22f, the static electricity generated by the friction of the hollow fiber membrane 20 can be grounded. Since it can escape to the case 12, the foreign matter D is more easily removed from the hollow fiber membrane 20.

  If the pore diameter of the hollow fiber membrane 20 is less than 1 μm, pressure loss increases and the filtration area increases, but the pore diameter is 2 μm or more, specifically 2.5 μm, so the filtration area is suppressed, The filter unit 2 can be reduced in size.

  FIG. 5 is a system diagram showing a gas purification system according to the second embodiment. The second embodiment is used in a case where gas supply cannot be stopped, such as city gas, and the two filter units described above are arranged in parallel and the introduction passage 4 is branched into two. The branch introduction passages 40A and 40B are connected to the first and second filter units 2A and 2B, respectively, and the first on-off valves V1A and V1B are provided in the branch introduction passages 40A and 40B, respectively. Also, second on-off valves V2A and V2B are provided in the branch lead-out passages 60A and 60B from the first and second filter units 2A and 2B, respectively. The branch lead-out passages 60 </ b> A and 60 </ b> B are combined to form a lead-out passage 6.

  According to the second embodiment, since the first on-off valves V1A and V1B and the second on-off valves V2A and V2B are switched, it is possible to select which one of the first and second filter units 2A and 2B to use. The foreign matter D attached to the filter module 10 can be removed by removing the filter module 10 from the unused filter unit and applying an impact as described above. Thereby, the life of the filter module 10 can be extended, and the filter module 10 can be cleaned or replaced without stopping the supply of gas.

  FIG. 6 is a system diagram showing a gas purification system according to the third embodiment. Similarly to the second embodiment, the third embodiment is also used in a case where the supply of gas cannot be stopped. In the third embodiment, the filter module is a raw gas DS introduced into the filter unit 2. 10 is backwashed. That is, the upstream side of the first on-off valve V1 in the introduction passage 4 and the upstream side of the second on-off valve V2 in the lead-out passage 6 are connected by the backwash introduction passage 35, and the backwash introduction passage A first switching valve 31 and a second switching valve 32 are provided in the vicinity of the connecting portion of the introduction passage 4 and the outlet passage 6 in 35. Further, the downstream side of the first on-off valve V1 in the introduction passage 4 and the downstream side of the second on-off valve V2 in the lead-out passage 6 are connected by a backwashing lead-out passage 36, and the backwash introduction passage A third switching valve 33 and a fourth switching valve 34 are provided in the vicinity of the connection portion of the introduction passage 4 and the outlet passage 6 in 36. Further, a backwash filter 38 is provided between the third switching valve 33 and the fourth switching valve 34 in the backwash introduction passage 34.

  Next, the operation of this system will be described. During normal gas purification, the first and second on-off valves V1 and V2 are opened, and the third on-off valve V3 and the first to fourth switching valves 31 to 34 are closed. Is flowing in the direction indicated by arrow A1. When performing backflow cleaning, as shown in FIG. 7, the first to third valves V1 to V3 are closed and the first to fourth switching valves 31 to 34 are opened. As a result, the gas flows in the direction indicated by the arrow A2, that is, in the direction opposite to that during gas purification in the filter module 10.

  As described in FIG. 3 of the first embodiment, the foreign matter D removed from the introduced gas DG during gas purification adheres to the outer wall 20d of the hollow fiber membrane 20. At the time of backwashing, as indicated by an arrow A3 in FIG. 8, the gas flows in the opposite direction to that at the time of gas purification, that is, from the hollow portion 20c of the hollow fiber membrane 20 toward the outer wall 20d. The foreign matter D adhering to is removed, and is discharged from the lower part of the filter module 10 on the gas flow A2 of FIG. The discharged foreign matter D is captured by the backwash filter 38 and led out to the lead-out passage 6 as a clean purified gas CG. When the backwashing is completed, each valve is returned to the normal gas purification state, and the gas purification is continued. As the backwash filter 38, various filters such as a hollow fiber membrane filter, a pleated membrane filter, and a flat membrane filter can be used.

  According to the third embodiment, similarly to the second embodiment, the filter module 10 can be cleaned without stopping the supply of gas. By repeatedly using the filter module 10, the filter module 10 Life can be extended. Further, since cleaning is performed by backwashing, only one filter unit 2 is required, and it is not necessary to remove the cover 19 of the filter unit 2 and take out the filter module 10 during cleaning. Therefore, the filter module 10 can be easily cleaned. It can be carried out.

  FIG. 9 is a system diagram showing a gas purification system according to the fourth embodiment. Similarly to the second and third embodiments, the fourth embodiment is used for a case where the supply of gas cannot be stopped. In the fourth embodiment, the first and second filter units 2A and 2B are selectively used as in the second embodiment of FIG. 5, and the first embodiment is similar to the third embodiment of FIGS. The filter module 10 is backwashed with the raw gas DS introduced into the second filter units 2A and 2B. That is, the first switching valve 41 is provided upstream of the branch introduction passages 40A and 40B in the introduction passage 4 of FIG. 6, and the upstream side of the first switching valve 41 in the introduction passage 4 and the branch derivation passage 60A. , 60B are connected to the upstream side of the second on-off valves V2A, V2B by backwash introduction passages 44A, 44B, respectively, and the second switching valve 42, the second 3 switching valves 43 are provided. In the present embodiment, the backwash introduction passages 44A and 44B have a common portion connected to the introduction passage 4 and two branch portions branched from the common portion and connected to the branch outlet passages 60A and 60B. is doing.

  Next, the operation of this system will be described. When purifying gas using the first filter unit 2A, the first and second on-off valves V1A and V2A and the first switching valve 41 for the first filter unit 2A are opened, and the second filter unit 2B is opened. The first to third on-off valves V1B to 3B and the second and third switching valves 42 and 43 are closed. In this state, the gas flows in the direction indicated by the arrow A1a and is purified by the first filter unit 2A. When purifying gas using the second filter unit 2B, the first and second on-off valves V1B and V2B and the first switching valve 41 for the second filter unit 2B are opened, and the first filter unit 2A is opened. The first to third on-off valves V1A to 3A and the second and third switching valves 42 and 43 are closed. In this state, the gas flows in the direction indicated by the arrow A1b and is purified by the second filter unit 2B.

  When performing the back flow cleaning of the first filter unit 2A, as shown in FIG. 10, the first switching valve 41, the second and third on-off valves V2A, V3A of the first filter unit 2A, The second on-off valve V3B of the second filter unit 2B, the second switching valve 42 for the first filter unit 2A, the first and second on-off valves V1B for the second filter unit 2B, V2B and the first on-off valve V1A of the first filter unit 2A are opened. As a result, the gas flows in the direction indicated by arrow A2a, that is, in the direction opposite to that during gas purification, in the filter module 10 of the first filter unit 2A. At the time of backwashing, as described with reference to FIG. 8 of the third embodiment, the foreign matter D attached to the outer wall 20d of the hollow fiber membrane 20 is removed by the gas flow in the reverse direction. The removed foreign matter D rides on the gas flow, is captured by the second filter unit 2B in FIG. 8, and is led to the lead-out passage 6 through the branch lead-out passage 60B as a clean gas. After the backwashing is completed, each valve is returned to the normal gas purification state, and the gas purification is continued.

  When performing the back flow cleaning of the second filter unit 2B, as shown in FIG. 11, the first switching valve 41, the second and third on-off valves V2B, V3B for the second filter unit 2B, The third on-off valve V3A for the first filter unit 2A is closed, the third switching valve 43 for the second filter unit 2B, and the first and second on-off valves for the first filter unit 2A V1A and V2A and the first on-off valve V1B for the second filter unit 2B are opened. Thereby, gas flows in the direction shown by arrow A2b. At the time of backwashing, the foreign matter D adhering to the filter module 10 is removed by the reverse gas flow as described above, and the removed foreign matter D gets on the gas flow and is captured by the first filter unit 2A. As a clean gas, the gas is led to the lead-out passage 6 through the branch lead-out passage 60A. After the backwashing is completed, each valve is returned to the normal gas purification state, and the gas purification is continued.

  According to the fourth embodiment, similarly to the second and third embodiments, the hollow fiber membrane 20 can be cleaned without stopping the supply of gas, and the hollow fiber membrane 20 can be used repeatedly. The life of the filter module 10 can be extended. Further, similarly to the third embodiment, it is not necessary to remove the filter module 10 by removing the lid portions 19 of the filter units 2A and 2B at the time of cleaning, so that the filter module 10 can be easily cleaned. Furthermore, by providing two filter units, even if one filter unit 2A or 2B fails, the gas purification function can be maintained using the other filter unit 2B or 2A. In addition, since the backflow cleaning is performed so that the foreign matter D removed from one filter module 10 is captured by the other filter module 10, the backwashing filter 38 as in the third embodiment is provided. Can be omitted.

  As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but various additions, modifications, or deletions can be made without departing from the spirit of the present invention. Therefore, such a thing is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Gas purification system 2 Filter unit 10 Filter module 12 Filter case 14 Inlet port 16 Outlet port 20 Hollow fiber membrane 20a Upper end part 20b Lower end part 22 Cartridge 28 Stopper 30 Impeller D Foreign object DG Original gas CG Purified gas

Claims (6)

A filter unit that removes foreign matter contained in gas by a filter module,
A filter case for storing the filter module;
The filter case is formed with an introduction port for introducing the gas into the filter module at the lower part, and an outlet port for deriving the gas that has passed through the filter module is formed at the upper part.
The filter module includes a plurality of hollow fiber membranes extending in a vertical direction in a cartridge, an upper end portion of the hollow fiber membrane being a fixed end fixed to the cartridge, and a lower end portion being a free end.   The filter unit according to claim 1, further comprising an impeller that swirls the gas introduced from the introduction port at a lower portion in the filter case.   3. The filter unit according to claim 2, wherein the impeller is provided in a stopper that is disposed below the filter module and prevents the filter module from dropping.   4. The filter unit according to claim 3, wherein the filter module is in electrical contact with a filter case made of a conductive material.   The filter unit according to any one of claims 1 to 4, wherein a hole diameter of the hollow fiber membrane is 2 µm or more. A gas purification system using the filter unit according to any one of claims 1 to 5,
A gas purification system comprising backwashing means for backwashing the filter module with gas introduced into the filter unit.

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