JP2009172519A - Filter apparatus, waterproof case with filter apparatus installed, and removing method of hematite caught by porous film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter apparatus which can maintain functions of the filter apparatus such as an aeration performance for a long period by removing hematite adhering to the filter apparatus by a simple method. <P>SOLUTION: The filter apparatus 10 includes a porous film 14 having functions catching hematite 20 and a magnet 16 giving magnetic force to hematite 20 caught by the porous film 14. Further, the filter apparatus 10 includes an auxiliary magnet 18, and a frame 19 fixing the porous film 14, the magnet 16, and the auxiliary magnet 18. In order to assure the circulation property of air, circulating holes 22 are provided on the magnet 16 and the auxiliary magnet 18, and openings 23 on the frame 19. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a filter device, a waterproof case in which the filter device is installed, and a method for removing hematite trapped by the porous membrane, and can remove hematite adhering to the porous membrane of the filter device by a particularly simple method. It relates to a possible filter device.

  Filter devices having a function of removing a specific component contained in a liquid or gas are used in various fields such as various vehicles, various electronic devices, and industrial processes. Hematite is often present in the environment in which these filter devices are used. Hematite is a major component contained in red soil, a reddish brown clay. Since red soil exists everywhere in the world, the hematite contained in it is also everywhere.

  The filter device includes a porous membrane having a plurality of pores, and when hematite adheres to the porous membrane, the pores are blocked and liquid or gas cannot pass, or the properties of the porous membrane change. For example, the function of the filter device may be impaired. As an example in which the function of the filter device is impaired due to the adhesion of hematite, there is a ventilation filter attached to a waterproof case storing a pressure sensor of an electronic device that measures the pressure. Since this ventilation filter is used in a waterproof case, a ventilation filter having a porous film made of a resin having high water repellency and excellent durability and antifouling property, for example, polytetrafluoroethylene (PTFE) is used. in use.

  PTFE, which is a constituent material of the porous membrane, is an excellent material as described above, but it has been confirmed that the ventilation performance of the ventilation filter deteriorates due to long-term use. The main factor for the deterioration of the air permeability is the deterioration of the water repellency of the porous membrane, and this deterioration of the water repellency is due to the adhesion of hematite.

  As a method for removing hematite adhering to the porous membrane of the filter device, high-pressure water washing or ultrasonic washing can be considered, but in any case, it is necessary to remove the waterproof case from the electronic device etc. Removal is not easy. In the case where a problem of poor air permeability occurs in the ventilation filter, the ventilation filter is replaced. Normally, the entire block including the atmospheric pressure sensor is replaced.

  As described above, according to the prior art, there is no effective means for removing hematite adhering to the porous membrane of the ventilation filter, and the ventilation filter is currently replaced and discarded together with the block including it. .

  An object of the present invention is to provide a filter device capable of removing the hematite adhering to the porous membrane of the filter device by a simple method and maintaining the function of the filter device such as aeration performance over a long period of time. It is.

  The filter device according to the present invention includes a porous membrane having a plurality of pores, and the porous membrane is a filter device having a function of capturing hematite contained in a gas or liquid passed through the membrane. A magnet for applying a magnetic force to the hematite captured by the porous membrane is provided in the vicinity of the introduction surface into which the gas or liquid is introduced.

  Moreover, it is preferable that a magnet has a flow hole through which gas or liquid passes.

  In addition, it is preferable to provide a frame that fixes the porous membrane and the magnet and holds the magnet at a position close to the introduction surface of the porous membrane, and the frame has an opening through which gas or liquid passes.

  Furthermore, it is preferable to provide an auxiliary magnet or a magnetic body at a position close to the lead-out surface from which the gas or liquid of the porous film is led out.

  The waterproof case according to the present invention has a plurality of through holes, and in the waterproof case in which a filter device that does not allow water to pass is installed in the through hole, at least one of the filter devices is the filter device according to the present invention. It is characterized by being.

  The method for removing hematite captured by the porous membrane according to the present invention includes a porous membrane having a plurality of pores, and the porous membrane has a function of capturing hematite contained in a gas or liquid passed through the membrane. Is a method for removing hematite trapped by a porous membrane in a filter device having a magnetic property, wherein hematite is denatured into magnetite, which is a magnetic substance, by applying a magnetic force to hematite under conditions where water acts on hematite. The magnetite is removed by being separated from the porous film by magnetic force.

  According to the filter device according to the present invention, a magnet for applying a magnetic force to the hematite captured by the porous membrane is provided at a position close to the introduction surface where the gas or liquid of the porous membrane is introduced. Hematite can be denatured into magnetite, which is a magnetic substance, and the magnetite can be removed from the porous film by magnetic force. Therefore, hematite is not accumulated in the porous membrane of the filter device, and it is possible to maintain the function of the filter device such as ventilation performance over a long period of time.

  Moreover, since the magnet has a flow hole through which gas or liquid passes, it is possible to ensure the flow of gas or liquid with respect to the introduction surface of the porous membrane.

  Further, since the porous membrane and the magnet are fixed and the frame is provided to hold the magnet at a position close to the introduction surface of the porous membrane, it is possible to configure a filter device in which components such as the porous membrane function integrally. it can. Since the frame is provided with an opening through which gas or liquid passes, the flowability of the gas or liquid with respect to the introduction surface of the porous membrane is good.

  Furthermore, since an auxiliary magnet or a magnetic material is provided at a position close to the lead-out surface from which the gas or liquid of the porous film is led out, it can supplement the function of the magnet and efficiently apply a magnetic force to the hematite. it can.

  In the waterproof case according to the present invention, since at least one of the filter devices is the above-described filter device according to the present invention, it is possible to maintain the ventilation performance to the inside of the waterproof case over a long period of time.

  The method for removing hematite trapped in the porous membrane according to the present invention is to modify hematite to magnetite, which is a magnetic substance, by applying a magnetic force to hematite under conditions where water acts on hematite. Is removed from the porous membrane by the magnetic force, so that hematite is not accumulated in the porous membrane of the filter device, and it is possible to maintain the function of the filter device such as aeration performance over a long period of time. .

  Embodiments according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram of a pressure sensor block mounted on an electronic device or the like, and is a view illustrating a waterproof case storing a pressure sensor and a state where a filter device is installed in a through hole of the waterproof case. FIG. 2 is a cross-sectional view of a main part of the filter device installed in the through hole of the waterproof case.

  As shown in FIGS. 1 and 2, the filter device 10 is installed in the through hole 13 of the waterproof case 12 that houses the atmospheric pressure sensor 11. The filter device 10 functions as a ventilation filter that captures water and dust and allows only air to pass through. Hereinafter, the filter device 10 will be described as a ventilation filter that does not allow water or dust to pass through. However, the filter device 10 is not limited to this, and is used in an environment where hematite contained in a gas or liquid is captured by a porous film. For example, a filter device that extracts a specific component from various liquids can be used.

  The atmospheric pressure sensor 11 is stored in a waterproof case 12 and mounted in an electronic device. The atmospheric pressure detected by the atmospheric pressure sensor 11 is used for various data corrections.

  The atmospheric pressure sensor 11 is stored in the waterproof case 12 as described above because it may cause a malfunction when exposed to water or dust. However, in order to measure the atmospheric pressure, it is necessary to circulate air into the waterproof case 12, so the waterproof case 12 is provided with a through hole 13. The through-hole 13 is provided with a filter device 10 that allows only air to pass through.

  The filter device 10 includes a porous membrane 14 as shown in FIG. A magnet 16 is provided on a surface of the porous membrane 14 facing the outer side of the waterproof case 12, that is, a position close to the introduction surface 15 into which air is introduced. Further, an auxiliary magnet 18 is provided on the surface of the porous membrane 14 facing the inside of the waterproof case 12, that is, at a position close to the lead-out surface 17 through which the air that has passed through the porous membrane 14 is led out.

  The filter device 10 further includes a frame 19 that fixes the porous membrane 14, the magnet 16, and the auxiliary magnet 18. A grommet 25 is fitted into the frame 19 and is installed in the through hole 13 of the waterproof case 12. .

  The porous membrane 14 has a plurality of pores, and basically has a function of capturing a specific component having a size larger than the pore diameter. One of the specific components is hematite 20 contained in the air passed through the porous membrane 14. Therefore, the pore diameter is required to be smaller than the size of hematite 20. The hematite 20 is a main component of red soil, and since red soil exists throughout the world, the hematite 20 also exists in the same manner. Since the red soil is deposited on the road surface or scattered in the atmosphere, the red soil enters the electronic device by measurement in the field and is captured by the porous film 14.

  As long as the porous membrane 14 has the above-mentioned pore diameter, those made of various materials and structures, for example, a polymer porous membrane and a ceramic porous membrane can be used. Polymer porous membranes and ceramic porous membranes include membranes produced by various production methods (phase separation method, extraction method, chemical treatment method, foaming method, fiberizing method, sintering method, etc.) and various resins. (Acrylic resin, olefin resin, silicone resin, fluororesin, polyimide resin, cellulose resin, etc.) and a film composed of various ceramics (titanium oxide, silica, etc.) can be used. However, as shown in FIG. 1, when used in a pressure sensor block, it is preferable to use a porous film 14 having excellent water repellency and durability. Specifically, the porous film 14 is a porous polymer film made of a fluororesin such as polytetrafluoroethylene (PTFE) that is particularly excellent in water repellency and durability. Further, the porous membrane 14 is preferably supported by being affixed to a nonwoven fabric or the like in order to increase the mechanical strength. A support 21 such as a nonwoven fabric is provided on the lead-out surface 17 side of the porous membrane 14 as shown in FIG.

  The magnet 16 is a member having a function of applying a magnetic force to the hematite 20 captured by the porous film 14. The magnet 16 generates a bipolar magnetic field, and may be a permanent magnet or an electromagnet. When using an electromagnet, it is necessary to supply an electric current from the outside. When a permanent magnet is used, it is not necessary to consider the supply of current, so that there is an advantage that the structure of the filter device 10 becomes simple and there is no problem such as disconnection of the electric wire. On the other hand, when an electromagnet is used, there is an advantage that the magnetic force applied to the hematite 20 can be easily changed by controlling the amount of current supplied. Below, although the magnet 16 is demonstrated in detail as a permanent magnet, it is not limited to this.

  As shown in FIG. 2, the magnet 16 has a thin plate shape, and is fixed to the frame 19 and held at a position close to the introduction surface 15 of the porous film 14. By using the frame 19 that can change the position of the magnet 16 with respect to the introduction surface 15, the distance between the magnet 16 and the introduction surface 15 can be easily adjusted. Accordingly, when it is desired to increase the magnetic force applied to the hematite 20 captured by the porous film 14, the fixing position of the frame 19 can be adjusted so that the distance between the magnet 16 and the porous film 14 is shortened. .

  The magnet 16 is provided so as to cover the introduction surface 15. The magnet 16 can be provided so as to cover a part of the introduction surface 15, but it is provided so as to cover the entire surface in order to uniformly apply a magnetic force to the hematite 20 captured by the porous film 14. Is preferred.

  In order to ensure air circulation with respect to the introduction surface 15, the magnet 16 is provided with a circulation hole 22 through which air passes. The size and number of the flow holes 22 can be set in consideration of the strength of the magnetic force applied to the hematite 20. That is, when the size of the circulation hole 22 is increased and the number thereof is increased, the magnetic force applied to the hematite 20 is weakened, but the air circulation is promoted. On the other hand, if the size of the circulation holes 22 is reduced and the number thereof is reduced, the magnetic force applied to the hematite 20 is increased, but the air circulation property is lowered. As will be described later, by providing an opening 23 in the frame 19, even when the magnet 16 is provided so as to cover the entire introduction surface 15, air circulation is ensured without providing the circulation hole 22. You can also

  One of the thin plate-shaped surfaces is an S pole and the other is an N pole, and the magnet 16 is provided with the S pole surface 16s facing the introduction surface 15 as shown in FIG. An auxiliary magnet 18 to be described later is also provided such that one of the thin plate-shaped surfaces is the S pole and the other is the N pole, and the N pole surface 18 n faces the lead-out surface 17. The N pole surface 16n of the magnet 16 can be provided in the direction of the introduction surface 15, or the S pole side and the N pole side can be alternately arranged by using a plurality of magnets 16.

  Various shapes and compositions of the magnet 16 can be used, but the shape of the magnet 16 is preferably a thin plate from the viewpoint of downsizing the filter device 10 or the like.

  By applying a magnetic force to the hematite 20 by the magnet 16, the hematite 20 is denatured into a magnetite 24. The hematite 20 is a non-magnetic material, while the magnetite 24 is a magnetic material. Accordingly, the magnetite 24 is pulled away from the porous film 14 by the magnetic force of the magnet 16 and is attracted to the magnet 16. The magnet 16 is a member that exhibits the effects as described above, and is an extremely important component in the filter device 10. The detailed operation of the filter device 10 including the magnet 16 will be described later.

  As shown in FIG. 2, the filter device 10 is provided with an auxiliary magnet 18 that supplements the function of the magnet 16. The auxiliary magnet 18 is a thin plate-shaped permanent magnet. As the auxiliary magnet 18, as with the magnet 16, an electromagnet can be used. The auxiliary magnet 18 is a member having a function of applying a magnetic force to the hematite 20 captured by the porous film 14, similarly to the magnet 16, but the magnetic force is set to be weaker than the magnetic force by the magnet 16. Has been. The auxiliary magnet 18 is provided for the purpose of increasing the magnetic force applied to the hematite 20 by reducing the magnetic force deviating from the direction of the porous film 14 by directing the magnetic force of the magnet 16 toward the porous film 14. ing. Therefore, a magnetic body can be provided instead of the auxiliary magnet 18.

  The magnetic material means a ferromagnetic material that is magnetized by an external magnetic field, and includes a hard magnetic material and a soft magnetic material. The hard magnetic material is a magnetic material that maintains the magnetization even when the external magnetic field is removed, and the soft magnetic material is a magnetic material that returns to its original state when the external magnetic field is removed. Regardless of which magnetic material is used, the magnetic force of the magnet 16 is directed toward the porous film 14 so that the magnetic force of the magnet 16 is efficiently applied to the hematite 20 as described above. Thus, the magnetic force deviating from the direction of the porous film 14 can be reduced, and the magnetic force applied to the hematite 20 can be increased.

  As shown in FIG. 2, the auxiliary magnet 18 is fixed to the frame 19 together with the porous membrane 14 and the magnet 16 and is held at a position close to the lead-out surface 17 of the porous membrane 14. Since the support 21 is provided in front of the porous membrane 14, the auxiliary magnet 18 cannot be as close to the porous membrane 14 as the magnet 16. The distance between the auxiliary magnet 18 and the lead-out surface 17 can be easily adjusted by using the frame 19 that can change the position of the auxiliary magnet 18 with respect to the lead-out surface 17. The magnetic force of the magnet 16 and the auxiliary magnet 18 can be adjusted not only by the magnitude of the magnetic force of the magnet but also by the position fixed to the frame 19.

  The auxiliary magnet 18 is provided so as to cover the lead-out surface 17 of the porous film 14. In order to ensure the flowability of the air led out from the lead-out surface 17, the auxiliary magnet 18 is provided with a flow hole 22 through which air similar to the magnet 16 passes.

  As described above, the auxiliary magnet 18 is also provided with one of the thin plate-shaped surfaces being the S pole and the other being the N pole, with the N pole surface 18 n facing the lead-out surface 17. As a combination of the magnetic poles of the magnet 16 and the auxiliary magnet 18 facing the direction of the porous film 14, the magnet 16 shown in FIG. 2 is a combination in which the S pole surface and the auxiliary magnet 18 are the N pole surface, and the magnet 16 is N A combination in which the pole surface / auxiliary magnet 18 is an S pole surface is preferable, and a combination in which the magnet 16 is an S pole surface / auxiliary magnet 18 is an N pole surface is particularly preferable. In this case, a magnetic force can be applied to the hematite 20 captured by the porous film 14 more efficiently. A magnetic material may be used in place of the auxiliary magnet 18. In this case, the magnetic pole of the magnet 16 facing the direction of the porous film 14 may be either the S pole face or the N pole face, but is preferably the S pole face.

  The frame 19 has a function of fixing the porous membrane 14, the magnet 16, and the auxiliary magnet 18 as described above. The frame 19 holds the magnet 16 at a position close to the introduction surface 15 of the porous film 14, and the auxiliary magnet 18 at a position close to the lead-out surface 17 of the porous film 14. A grommet 25 is fitted into the frame 19, and the filter device 10 is installed in the through hole 13 of the waterproof case 12 through the grommet 25.

  The frame 19 has a ring shape and includes an opening 23 between the porous membrane 14 and the magnet 16. The opening 23 is provided to promote air circulation with respect to the introduction surface 15. The frame 19 includes an opening 23 between the porous film 14 and the auxiliary magnet 18 in order to promote the flow of air passing through the porous film 14 even inside the waterproof case 12. .

  As described above, the waterproof case 12 is a case for storing the atmospheric pressure sensor 11 and ensuring an internal waterproof environment and a dust-free environment. The waterproof case 12 is provided with at least one through hole 13 for introducing air.

  The through holes 13 of the waterproof case 12 can be provided at two locations as shown in FIG. A filter device 10 is installed in one of the through holes 13, and a filter composed only of the porous film 14 is installed in the other through hole 13. Since the filter device 10 is installed in the waterproof case 12 shown in FIG. 3, the ventilation performance into the waterproof case 12 can be maintained over a long period of time.

  3 is provided with a filter device composed only of the porous membrane 14, this filter device is used as a main filter, and the filter device 10 is used as a sub-filter. Can do. When the filter device 10 is used for the purpose of supplementing the function of the main filter in this way, the magnet 16 is installed at a distance very close to the porous membrane 14 (in this case, the opening 23 of the frame 19 is reduced). Or the like, or by reducing the number of flow holes 22, it is possible to further improve the removal performance of the hematite 20. According to this waterproof case 12, until the main filter is deteriorated due to the adhesion of the hematite 20, the best condition with good air permeability is maintained, and after the deterioration, the minimum ventilation performance for functioning the atmospheric pressure sensor 11 is ensured. It becomes possible to do.

  The effect | action of the filter apparatus 10 of the said structure is further demonstrated in detail below, adding FIG. FIG. 4 is a diagram showing how hematite 20 captured by the porous film 14 in FIG. 2 is removed.

  As described above, the filter device 10 is installed in the through hole 13 of the waterproof case 12, and only air is introduced into the waterproof case 12. As shown by arrows in FIG. 4, the air flow is introduced into the waterproof case 12 from the introduction surface 15 of the porous membrane 14 through the flow hole 22 of the magnet 16 and the opening 23 of the frame 19. Further, air passes through the porous membrane 14 and the support 21 from the introduction surface 15, and is diffused into the waterproof case 12 through the flow hole 22 of the auxiliary magnet 18 and the opening 23 of the frame 19. Since air circulation is ensured, the atmospheric pressure sensor 11 can detect atmospheric pressure.

  The air passing through the porous membrane 14 contains hematite 20 and water (not shown). The hematite 20 cannot pass through the porous film 14 and is captured by the porous film 14. Specifically, it adheres to the introduction surface 15. Water cannot pass through the porous membrane 14, and this water acts on the hematite 20 attached to the introduction surface 15 of the porous membrane 14.

  Since PTFE, which is a constituent material of the porous membrane 14, is excellent in water repellency, it repels water and the introduction surface 15 is difficult to get wet. However, when hematite 20 adheres, the water repellency of PTFE constituting the porous membrane 14 is lowered, and the introduction surface 15 becomes wet. When the introduction surface 15 gets wet with water, the ventilation performance of the filter device 10 is lowered. Therefore, it is necessary to remove hematite 20 which is a cause of a decrease in water repellency.

  The magnet 16 is fixed with the S pole surface 16s facing the introduction surface 15 side, and the auxiliary magnet 18 is fixed with the N pole surface 18n facing the lead-out surface 17 side. The distance between the magnet 16 and the auxiliary magnet 18 is close, and the lines of magnetic force α can be drawn from the magnet 16 toward the auxiliary magnet 18 as shown in FIG. Naturally, there are magnetic field lines other than α. The hematite 20 attached to the porous film 14 is applied with a magnetic force from the magnet 16. The auxiliary magnet 18 allows the magnetic force of the magnet 16 to be directed in the direction of the porous film 14, thereby reducing the magnetic force deviating from the direction of the porous film 14 and increasing the magnetic force applied to the hematite 20. A magnetic force can be applied to the hematite 20 well.

When a magnetic force is applied to the hematite 20 under conditions where water acts on the hematite 20, the hematite 20 is denatured into a magnetite 24. The detailed mechanism by which this hematite 20 is denatured into magnetite 24 has not yet been clarified, but it is considered that the following reactions are involved.
Fe ₂ O ₃ + 6H ⁺ + 2e ⁻ → 2Fe ²⁺ + 3H ₂ O (1)
Fe ²⁺ + 8FeOOH + 2e ⁻ → 3Fe ₃ O ₄ + 4H ₂ O (2)
Here, Fe ₂ O ₃ is hematite 20 and Fe ₃ O ₄ is magnetite 24. The presence of the divalent iron ion Fe ²⁺ is important for this modification reaction, and the reaction of the divalent iron ion Fe ^{2+ to} the trivalent iron ion Fe ³⁺ is suppressed by the magnetic force, and the reaction of the formula (2) is promoted. It is considered to be done.

  Conditions for promoting the modification reaction of the hematite 20 include that water necessary for the reaction acts on the hematite 20 and that the magnetic force applied to the hematite 20 is strong. Further, although it depends on the strength of the magnetic force, the amount of acting water, the temperature and the like, the time required for the modification of the hematite 20 usually requires several days or weeks. Therefore, in order to prevent the hematite 20 from accumulating in the porous film 14, it is preferable to apply a magnetic force from the magnet 16 for a long time.

  Since the inside of the electronic device is humid, and the hematite 20 easily absorbs water, a sufficient amount of water is acting on the hematite 20 for the modification reaction. In addition, water can be positively supplied to the hematite 20 by providing means for supplying water to the introduction surface 15 of the porous membrane 14.

  Since the hematite 20 is a non-magnetic material, it cannot be moved by a magnetic force. However, since the magnetite 24 is a magnetic material, it is attracted to the magnet 16 and moves. Therefore, the magnetite 24 is pulled away from the porous film 14 by the magnetic force applied from the magnet 16 and removed. The magnetite 24 removed from the porous film 14 adheres to the magnet 16. In addition, since the magnetic force applied to the hematite 20 by the auxiliary magnet 18 is weaker than the magnetic force of the magnet 16, the magnetite 24 is not attracted in the direction of the auxiliary magnet 18.

  Actually, the magnetite 24 is often pulled away from the porous film 14 and removed when the porous film 14 is in a dry state. When the electronic device is in operation or in the rain, it is likely to be in a humid condition, and water tends to act on the introduction surface 15 of the porous membrane 14. As described above, when the hematite 20 adheres to the porous film 14, the water repellency of the porous film 14 decreases, so that the porous film 14 gets wet. This water is indispensable for the modification reaction of the hematite 20, but binds the magnetite 24 to the porous film 14. On the other hand, the porous film 14 is in a dry state when the electronic device is stopped or when the weather is fine. When the introduction surface 15 of the porous film 14 is dried, the force for restraining the magnetite 24 is reduced, and the magnet 16 is provided close to the porous film 14, so that it is instantaneously attracted to the magnet 16 and is porous. It will be removed from the membrane 14.

  As described above, the hematite 20 attached to the filter device 10 is removed without removing the waterproof case 12 from the electronic device by a simple method using magnetic force, and the ventilation performance of the filter device 10 is maintained over a long period of time. It becomes possible to do. The method of removing the hematite 20 using this magnetic force does not require an artificial operation. It can be said that the filter device 10 is a filter device having a self-cleaning function of the hematite 20.

It is a schematic diagram of an atmospheric pressure sensor block mounted on an electronic device or the like, and is a diagram showing a state where a filter device is installed in a waterproof case for storing the atmospheric pressure sensor and a through hole of the waterproof case. It is principal part sectional drawing of the filter apparatus installed in the through-hole of a waterproof case. It is principal part sectional drawing of the waterproof case in embodiment which concerns on this invention. In FIG. 2, it is a figure which shows a mode that the used form of a porous membrane, especially a captured hematite are removed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Filter apparatus, 11 Atmospheric pressure sensor, 12 Waterproof case, 13 Through-hole, 14 Porous membrane, 15 Introduction surface, 16 Magnet, 17 Derivation surface, 18 Auxiliary magnet, 19 Frame, 20 Hematite, 21 Support body, 22 Through-hole, 23 openings, 24 magnetite, 25 grommets.

Claims (6)

In the filter device having a porous membrane having a plurality of pores, the porous membrane has a function of capturing hematite contained in the gas or liquid passed through the membrane,
A filter device comprising a magnet that applies a magnetic force to hematite captured by a porous membrane at a position close to an introduction surface into which a gas or liquid of the porous membrane is introduced. The filter device according to claim 1,
The magnet has a flow hole through which gas or liquid passes. The filter device according to claim 1 or 2,
It includes a frame that fixes the porous membrane and the magnet and holds the magnet at a position close to the introduction surface of the porous membrane,
The frame has an opening through which gas or liquid passes. The filter device according to any one of claims 1 to 3,
A filter device comprising an auxiliary magnet or a magnetic body at a position close to a lead-out surface from which a gas or liquid of the porous membrane is led. In a waterproof case with a plurality of through holes, in which a filter device that does not allow water to pass is installed,
A waterproof case provided with a filter device, wherein at least one of the filter devices is the filter device according to any one of claims 1 to 4. A porous membrane having a plurality of pores, the porous membrane is a method for removing hematite captured by the porous membrane in a filter device having a function of capturing hematite contained in a gas or liquid passed through the membrane There,
By applying a magnetic force to the hematite under conditions where water acts on the hematite, the hematite is denatured into a magnetite that is a magnetic material, and the magnetite is separated from the porous film by the magnetic force and removed. A method for removing hematite trapped in a porous membrane.

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