JPH04341313A - Filter of three dimensional fabric in the form of flat plate - Google Patents

Abstract

PURPOSE:To improve filtration durability by changing the insertion density of wefts in the thickness direction of a three dimensional fabric structure in the title filter comprising warps, wefts, and vertical threads so that the size of openings produced at the intersections of fiber bundles in the fabric structure is different between one side and the other side in the thickness direction. CONSTITUTION:The title filter 1 is composed of warp layers comprising warps Z arranged in parallel to the longitudinal direction of a fabric, wefts arranged in the lateral direction of a fabric rectangularly crossing with the warps, and vertical threads being continuous on each line arranged along the thickness direction of the fabric rectangularly crossing with the warps Z between the respective lines of the warp layers. The insertion density of wafts changes in the thickness direction of the three dimensional fabric structure so that the size of voids produced at the intersections of fiber bundles in the fabric structure F is different between one side and the other side in the thickness direction. As the result of this structure, a reinforcing material for the maintenance of the form becomes unnecessary, and the filtration area is substantially increased to improve the durability of filtration effects.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat three-dimensional fabric filter for collecting impurities in a fluid.

0002

2. Description of the Related Art Filtration using a filter is generally used as a method of collecting impurities present in a fluid. Commonly used filters have multiple layers of flat woven fabric to ensure their filtration function. However, filters using flat cloth have the following drawbacks. ■The compressed state of each layer changes due to the pressure of the fluid, creating gaps between each layer and causing them to float, or conversely, the upper layer sinks into the lower layer, resulting in an excessively dense state, which deteriorates filtration performance as processing time progresses. Change. ■Plane cloth itself lacks shape retention, so reinforcing material is required to maintain shape, which reduces the effective filtration area. ■If a flat cloth laminated filter is placed parallel to the fluid flow in order to increase the filtration area without changing the cross-sectional area much in a limited-sized flow path, when the flow direction changes In order to prevent disturbances in the set positions of the laminated fabrics due to pressure fluctuations on the filter surface caused by turbulent flow, a reinforcing material (
perforated plate) is required, which reduces the effective filtration area.

[0003]Furthermore, the aerosol collection action by a fiber filter includes an inertial action, a diffusion action, and an electrostatic action. In other words, the inertial effect is the effect of the aerosol adhering to the fiber due to the negative pressure caused by the vortex generated when the aerosol collides with the fiber, the diffusion effect is the effect of the aerosol colliding with the fiber, the flow velocity decreases, and it is deposited on the surface of the fiber, and the static electricity. The action is that the aerosol is adsorbed to the fibers due to the static electricity charged on the fibers. Among these, electrostatic action occurs in the case of fibers made of special materials, and aerosols are generally collected by inertial action and diffusion action. Since conventional filters made of woven or non-woven fabrics have a two-dimensional planar structure, it is difficult to simultaneously satisfy the above-mentioned inertial action and diffusion action, and it has been necessary to combine multiple filters to satisfy both actions. . To solve this problem, Japanese Patent Application Laid-Open No. 2-233115 proposes a fiber filter made of a three-dimensionally structured woven fabric made of three-component yarns, weft, warp, and perpendicular yarns, which are perpendicular to each other.

0004

[Problems to be Solved by the Invention] Since the three-dimensional structured fabric itself has a shape-retaining function, a fiber filter made of the three-dimensional structured fabric does not deform much when fluid passes through it, and requires reinforcement to maintain its shape. Since no material is required, the actual filtration area becomes larger, and the problems of the flat cloth laminated filter described above are solved. Since the three-dimensional structure fabric filter proposed in JP-A-2-233115 has a constant fiber pitch (filling density), there is no particular problem when the size of impurities contained in the fluid is constant. There is a problem when there is a wide range in the size of impurities. That is, since the pitch (packing density) of the fibers is set according to the minimum impurity to be collected, larger impurities are collected while covering the surface of the filter, reducing the sustainability of the filtration effect.

[0005] The present invention has been made in view of the above-mentioned problems, and its purpose is to eliminate the need for reinforcing materials to maintain the shape, increase the substantial filtration area, and improve the sustainability of the filtration effect. An object of the present invention is to provide a flat three-dimensional fabric filter.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the filter of the present invention is composed of a flat three-dimensional fabric in which fiber bundles are arranged in multiple directions in at least three axes of X, Y, and Z. The size of the voids generated at the intersection points of fiber bundles in the original fabric was made smaller on one side in the thickness direction of the three-dimensional fabric than on the other side.

[0007]

[Operation] In the flat filter of the present invention, the filter is arranged parallel to the flow of fluid, and the voids formed at the intersections of fiber bundles in the three-dimensional fabric constituting the filter are arranged from the large side to the small side. Used with fluid passing through it. Since the three-dimensional fabric constituting the filter itself has a shape-retaining function, it is less deformed when fluid passes through it, and there is no need for reinforcing materials to maintain the shape, resulting in a substantial filtration area. Since the fluid passes through the voids created at the intersections of fiber bundles from the large side to the small side, even if the size of impurities in the fluid varies, large impurities will be present in the large voids, and small impurities will be The filtering effect is maintained over a long period of time because it is captured and accumulated in the voids surrounded by the three-dimensional intersecting fibers in the small voids.

[0008]

【Example】

(Embodiment 1) A first embodiment embodying the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a partially cutaway perspective view of the three-dimensional textile structure F, and the three-dimensional textile structure F constituting the flat filter 1 is oriented in the longitudinal direction (Z direction) of the textile.
A warp layer consisting of a plurality of warp threads z arranged in parallel along the warp threads, weft threads x arranged in the width direction (X direction) of the fabric in a state perpendicular to the warp threads z, and between each row of the warp thread layers. and a plurality of vertical threads y that are continuous in each row and arranged in the thickness direction (Y direction) of the fabric in a state perpendicular to the warp threads z on both outer sides of the row. The insertion density of the weft x changes in the thickness direction of the three-dimensional woven structure F, and the fiber content of the three-dimensional woven structure F is smaller on one side in the thickness direction than on the other side. That is, the size of the voids generated at the intersections of fiber bundles in the three-dimensional woven structure F is larger on the upper side of FIG. 1 and smaller on the lower side in FIG. This three-dimensional woven structure F is manufactured by a known method (for example, JP-A-2-191743).

The fiber materials of the warp z, weft , amorphous fibers made of titanium, carbon, and oxygen with extremely high heat resistance; In applications where properties are not required, synthetic fiber filaments (polyester fibers, polyethylene fibers, polystyrene fibers, polypropylene fibers, etc.) are also used.

[0010] In the three-dimensional woven structure F, the threads intertwine and
By crimping, the thread forms a polygonal shape so as to fill the given space, but if the number of fibers that make up the thread is small, the space cannot be evenly filled and voids are created randomly, causing capture. There is a risk that the collection effect will vary. Therefore, it is desirable that the number of fibers constituting one yarn bundle is an aggregate of at least 70 or more thin fibers. Further, it is preferable that the diameter of each single fiber is thin and flexible, with a diameter of 100 μm or less, preferably 20 μm or less, for a greater space-filling effect.

[0011] Furthermore, the volume ratio occupied by the fibers in the total volume of the three-dimensional woven structure F is 35% or more, preferably 40% or more. In order to press the fiber bundles (threads) of each component of the filter together and sufficiently fill the voids that occur at the intersections of the fiber bundles, the outer shape of the fiber bundles should be polygonal to fill the voids around the fiber bundles. It is necessary to deform the fiber into a shape, and for that purpose, the content must be set to the above content so that the fibers are closely adhered to each other. In addition, the higher the fiber packing density, the more fine particles can be removed, but the fluid passage resistance increases, so it is important to determine the balance between the two. must also be selected appropriately.

Although one flat filter 1 can be used, in order to increase the filtration area, usually a large number of flat filters 1 are assembled in one housing 2 in multiple stages as shown in FIG. It is used as a filter device 3. The main body of the housing 2 is formed into a rectangular cylindrical shape and gradually becomes thinner toward the inlet 2a side and the outlet 2b side, and has a pair of rectangular compartments inside thereof perpendicular to the direction of fluid flow. The plates 4 and 5 are fixedly arranged so that their peripheral surfaces fit into the inner surface of the housing 2. Five through holes 6 are provided in the partition plate 4 arranged on the entrance 2a side.
are formed at predetermined intervals, and six through holes 7 are formed at equal intervals in the partition plate 5 disposed on the exit 2b side, with the phase shifted from the formation position of the through holes 6. Also, both partition plates 4,
Fitting grooves 4a and 5a into which the longitudinal end portions of the flat filter 1 are fitted are formed parallel to each other at constant intervals and at positions shifted by 1/2 pitch from each other on the mutually opposing surfaces of the filter 5. A large number (10 filters in this embodiment) of flat filters 1 are arranged so that their longitudinal ends are connected to the respective fitting grooves 4a, 5a.
When fitted, the two flat filters 1 are used as a set to form a triangular prism-shaped space in which the through hole 6 side formed in the partition plate 4 disposed on the inlet 2a side expands.
It is fixedly arranged in a zigzag manner between both partition plates 4 and 5. Each flat filter 1 is arranged such that the side of the three-dimensional textile structure F with a lower fiber packing density faces the fluid flowing in from the through holes 6. Further, both side surfaces of each flat filter 1 are tightly fixed to the inner wall of the housing 2.

Next, the operation of the filter device 3 constructed as described above will be explained. The fluid introduced into the housing 2 from the inlet 2a is guided through the through hole 6 of one partition plate 4 to a position corresponding to the filter surface of each flat filter 1, and the three-dimensional fabric constituting the flat filter 1 is guided to a position corresponding to the filter surface of each flat filter 1. Structure F
The fluid passes through the flat filter 1 from the side where the packing density of fibers is low to the side where the packing density is high, during which particulates and the like contained in the fluid are filtered out, and the purified fluid passes through the through holes 7 of the other partition plate 5. and is discharged from the outlet 2b. As the fluid to be filtered flows from the side of the three-dimensional textile structure F with a lower packing density of fibers to the side with a higher density of fibers as described above, even if there is a wide range in the size of impurities contained in the fluid to be filtered, large Impurities are trapped and accumulated in the voids surrounded by three-dimensionally intersecting fibers in areas where the fiber packing density is low, and small impurities are trapped in areas where the fiber packing density is high. Therefore, the filtration effect lasts for a long time compared to the case of using the three-dimensional woven structure F, which has a constant packing density in the thickness direction with the packing density of fibers matched to the minimum impurity to be collected. be done.

The three-dimensional woven structure F constituting the filtration section of the filter device 3 is different from the case where plane cloths are laminated, and the distance between each yarn constituting the three-dimensional woven structure F is fixed, so that the packing density of the fibers is fixed. is maintained in a stable state, resulting in stable filtration performance. In addition, since the three-dimensional woven structure F itself has a shape-retaining function, it is less deformed when fluid passes through it, eliminates the need for reinforcing materials to maintain its shape, and increases the effective filtration area. This also reliably avoids the problem of unstable filtration performance due to the gap between the reinforcing material and the fibers being misaligned due to the difference in coefficient of thermal expansion between the reinforcing material and the fibers. Moreover, since the trapped sediment is accumulated in the voids surrounded by the three-dimensionally intertwined fibers that constitute the three-dimensional textile structure F, the filtration effect is maintained for a long period of time.

When the three-dimensional textile structure F is applied to aerosol collection as described above, when the gas advances in the thickness direction of the side wall, the number of inertial impacts caused by the fibers arranged in multiple layers in the thickness direction increases. is increased, and the collection efficiency due to inertial action is improved. Furthermore, the gas flow rate is rapidly reduced by the inertial impact, and the collection efficiency due to the diffusion effect is also improved. When the surface of the three-dimensional textile structure F is arranged parallel or nearly parallel to the flow of fluid as in the filter device 3 of this embodiment, when the fluid passes through the three-dimensional textile structure F, The substantial thickness is increased and the filtration effect is improved.

[0016] In the case of a filter made of laminated flat cloth, when a certain amount of deposits accumulates due to use and the filtration effect decreases, the filter is disassembled and the deposits are washed and filtered.
Provide for reuse. In the case of a flat cloth, the surface layer on both the front and back sides can be exposed by disassembling the filter, so it is easy to wash and remove deposits. If the fiber layer is arranged and the fiber layer is thick, it is virtually impossible to remove the internal deposits by washing. If it is not possible to remove the deposits, there is no choice but to make them disposable. However, when the three-dimensional textile structure F is made of heat-resistant fibers, when the filtration effect decreases to some extent due to use, the fluid to be filtered may be bypassed, or the filtration may be temporarily interrupted and the filter device 3 may be attached. Remove it from the main body of the device,
After drying, the deposits can be burned or carbonized by heating in a heating furnace, and then the carbides can be removed by appropriate means (for example, applying vibration). The heat-resistant fibers used include ceramic fibers such as silicon carbide fibers, alumina fibers, and tyranno fibers, and metal fibers that can withstand temperatures of about 1000° C. at which ordinary materials burn in the air.

In the above case, when removing the deposits by heating, it is necessary to once remove the filter device 3 from the apparatus body to which it is attached and heat it in a heating furnace to burn or carbonize the deposits. Therefore, the filter device 3
It takes a lot of man-hours to remove and install. Also, since the filter device 3 is usually installed in a narrow space, it is difficult to remove it.
There are disadvantages such as the installation work being difficult to perform, and the work often being undesirable from a sanitary standpoint, such as when handling polluted substances such as soot. Therefore, it is preferable that the deposits can be removed without removing the filter device 3 from the device main body. In particular, when high-temperature gases or liquids are being filtered, cooling and heating associated with the removal and installation of the filter device 3 are not required, which is advantageous in terms of energy saving and efficiency improvement. Become.

In response to such demands, by weaving heat-generating filaments into the entire surface or part of the three-dimensional fabric structure F made of the heat-resistant fibers, the filter device 3 can be deposited without removing it from the device body. It becomes possible to remove objects. That is, in order to periodically burn and remove the trapped substances accumulated in the intersecting parts of the threads constituting the three-dimensional textile structure F, exothermic filaments are interwoven in advance, and when the filtration effect has decreased to a certain extent, the entrapment is removed. The supply of filtration fluid is stopped and a flow of air is supplied while the exothermic filament generates heat to burn off the deposits. When exothermic filaments are woven over the entire surface of the three-dimensional textile structure F, the entire deposit is combusted by generating heat from the exothermic filaments. In addition, when heat-generating filaments are woven into a part of the three-dimensional textile structure F, the airflow is caused to flow from the side with the heat-generating filaments,
The heat of combustion of the deposits is used to sequentially cause the fire to spread to the leeward side.

Examples of exothermic filaments include nichrome wire and Kanthal wire (molybdenum disilicide (Mo Si2) with a volume ratio of about 2
It is a cermet material mainly containing 0% glass-phase ceramic additives, and is used as a high-temperature heating element up to 1800°C. Metal wires are preferred because the amount of heat generated can be controlled depending on whether or not electricity is applied and the conditions, but there is no particular limitation. These heat-generating filaments may be used in alignment with the heat-resistant fibers to weave the three-dimensional textile structure F, but since these metal filaments have a large diameter and high rigidity, It can be used as a weft x in place of some heat-resistant fibers, or it can be used as a three-dimensional textile structure F.
It is preferable to use them by arranging them in a compressed manner on the inner or outer layer of the .

[0020] Furthermore, the three-dimensional woven structure F is made of heat-resistant fibers, and the filter device 3 is equipped with a burner nozzle capable of emitting a flame to the three-dimensional woven structure F incorporated in the filter device 3. , a burner nozzle may emit a flame to burn the deposits. (Embodiment 2) Next, a second embodiment will be explained according to FIG. The three-dimensional textile structure F in this example is a three-dimensional textile structure F.
It is composed of a large number of thin single fibers bundled together as weft yarns, and not only multifilaments that deform into polygonal (square) shapes when crimped, but also wires or monofilaments that do not deform when crimped. This is different from the three-dimensional textile structure F of the previous embodiment in that the weft yarns are used in the three-dimensional textile structure F and that the insertion density of the weft yarns is uniform throughout the three-dimensional textile structure F. That is, in the three-dimensional woven structure F of this embodiment, a weft x1 made of wire or monofilament is inserted into a location where the weft x was not inserted in the three-dimensional woven structure F of the previous embodiment.

Since the three-dimensional woven structure F of the above embodiment has fewer wefts x inserted toward one side in the thickness direction (upper part in FIG. 1), the flat filter 11 warps upward in FIG. There is a possibility. However, in the three-dimensional woven structure F of this embodiment, the insertion density of the wefts x and x1 is
Since it is formed uniformly throughout, there is no such possibility. Furthermore, even if the insertion density of the weft yarns x and x1 is uniform throughout the three-dimensional textile structure F, the weft yarn x1 made of wire or monofilament, unlike multifilament yarns, will not be as crimped to the adjacent warp yarns z or vertical yarns y. The cross section remains round without deformation. Therefore, a gap is created around the weft x1, and the fiber bundle (yarn) of the three-dimensional textile structure
The gap created at the intersection of the two becomes larger, making it easier for fluid to pass through.

(Embodiment 3) Next, a third embodiment will be explained with reference to FIG. This embodiment differs from the previous embodiment in that the structure of the inlet 2a side of the housing 2 is changed in a filter device 3 in which a large number of flat filters 1 are assembled in one housing 2 in multiple stages. ing. That is, in the space between the inlet 2a in the housing 2 and the partition plate 4, there is a plate-shaped plate that guides the fluid introduced into the housing 2 from the inlet 2a toward each through hole 6 formed in the partition plate 4. A plurality of fins 8 are provided.

Since the filter device 3 is narrower on the inlet 2a side than the place where the flat filter 1 is placed, if there is nothing between the inlet 2a and the place where the three-dimensional fabric structure F is placed, the fluid will flow through the housing 2. A large amount of deposits tends to be concentrated on the flat filter 1 located in the center of the screen, and the amount of deposits tends to be the largest in the central flat filter 1. However, when the fins 8 as described above are provided, the housing 2
The fluid introduced into the filter does not concentrate on the flat filter 1 in the center, but flows uniformly to the locations corresponding to all the flat filters 1, so that all the flat filters 1 function effectively and the filtration effect is improved. Improves sustainability.

It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, as shown in FIG.
A structure may be adopted in which flat filters 1 are arranged diagonally in multiple stages to increase the filtration area, and fins 8 are provided on the inlet side. In addition, as a three-dimensional textile structure F, the number of layers of the warp z and the weft x can be changed, and the number of layers of the warp z and weft A five-axis structure having bias threads disposed obliquely across each other may also be used. In addition, when the flat filter 1 is used as a filter device 3 arranged in multiple stages, fins are used as in the third embodiment to prevent the fluid introduced into the housing 2 from the inlet 2a from concentrating in the center. 8, the three-dimensional woven structure F placed near the center of the housing 2 may have a higher fiber density or a greater thickness to increase the resistance to fluid passage, and the flow will be directed toward the surrounding flat filter. It may be possible to make it easier to move toward 1.

[0025]

Effects of the Invention As detailed above, according to the present invention, unlike the case where plane cloths are laminated, the distance between the threads constituting the flat filter is fixed, and the packing density of the fibers is maintained in a stable state. filtration performance is stabilized. In addition, since the three-dimensional fabric that constitutes the filter itself has a shape-retaining function, it is less deformed when fluid passes through it, eliminates the need for reinforcing materials to maintain the shape, and increases the substantial filtration area. Since the fluid passes through the voids created at the intersections of fiber bundles from the large side to the small side, even if the size of impurities in the fluid varies, large impurities will be present in the large voids, and small impurities will be The filtering effect is maintained over a long period of time because it is captured and accumulated in the voids surrounded by the three-dimensional intersecting fibers in the small voids.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway schematic perspective view of a flat filter of a first embodiment.

FIG. 2 is a cross-sectional view of a filter device comprising a number of flat filters.

FIG. 3 is a partially cutaway schematic perspective view of a flat filter 1 according to a second embodiment.

FIG. 4 is a sectional view of a filter device according to a third embodiment.

FIG. 5 is a partial cross-sectional view of a modified filter device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Flat filter, 2... Housing, 3... Filter device, 4, 5... Partition plate, 8... Fin, F... Three-dimensional textile structure, x, x1... Weft, y... Vertical thread, z... Warp.

Claims (1)

[Claims] Claim 1: Consisting of a flat three-dimensional fabric in which fiber bundles are arranged in multiple directions in at least the three axes of X, Y, and Z, the size of the voids that occur at the intersections of the fiber bundles in the three-dimensional fabric is A flat three-dimensional fabric filter in which one side of the original fabric in the thickness direction is smaller than the other side.