Adsorption filter

Abstract

An adsorption filter (40) is provided with a band-shaped body that carries an adsorbent capable of adsorbing a specific substance and that is wound around a specific central axis. The band-shaped body is wound so as to overlap in two or more layers in the radial direction (RD) orthogonal to the central axis (CA). Furthermore, the band-shaped body is wound so as to be arranged side by side at least twice around an axial direction parallel to the central axis (CA). The band-shaped body overlapping in the radial direction (RD) defines a plurality of gaps G arranged side by side in the circumferential direction centered on the central axis (CA). A plurality of the gaps G are arranged side by side in the axial direction, and the plurality of gaps G arranged in the axial direction are connected to each other in the axial direction. When viewed facing the axial direction, the positions of the gaps G arranged side by side in the axial direction are shifted in the circumferential direction.

Description

Adsorption filter

[0001] The present disclosure relates to adsorption filters.

[0002] The adsorption filter disclosed in Patent Document 1 includes a first band and a second band. Each band carries an adsorbent. The first band is flat. The second band is wavy, with periodic concaves and convexes along the length of the second band. The first and second bands are overlapped. The first and second bands are wound so that the width direction of each band coincides with the direction of the central axis. This results in the overall outer shape of the first and second bands being cylindrical. The adsorption filter also has a gap between the first and second bands. The gap extends from the first end face to the second end face of the adsorption filter in the direction of the central axis. Therefore, air passes through this gap from the first end face to the second end face of the adsorption filter. At this time, the air comes into contact with the adsorbent carried by each strip, and specific adsorbate substances contained in the air are adsorbed by the adsorbent.

[0003] Japanese Patent Application Publication No. 8-141413

[0004] In the adsorption filter disclosed in Patent Document 1, the gaps are linear from the first end face to the second end face of the adsorption filter. Therefore, air flows quickly in a straight line from the first end face to the second end face of the adsorption filter. When the air flows quickly like this, the time that the air is in contact with the surface of the strip is shortened, and the adsorbed substance cannot be efficiently adsorbed by the adsorption filter.

[0005] In order to solve the above problems, the present disclosure provides an adsorption filter comprising a strip-shaped body that carries an adsorbent capable of adsorbing a specific substance and is wound around a specific central axis, the strip-shaped body being wound so as to overlap in two or more layers in a radial direction perpendicular to the central axis, and so as to be lined up in two or more laps in an axial direction parallel to the central axis, the strip-shaped body overlapping in the radial direction defines a plurality of gaps that are lined up in a circumferential direction centered on the central axis, the plurality of gaps are lined up in the axial direction, and the plurality of gaps lined up in the axial direction are connected to each other in the axial direction, and when viewed in the axial direction, the positions of the gaps lined up in the axial direction are shifted in the circumferential direction, and the area of ​​the region where two adjacent gaps in the axial direction overlap is smaller than the area of ​​each of the two gaps.

[0006] The adsorbate can be easily adsorbed onto the adsorbent.

[0007] Fig. 1 is a perspective view of the device. Fig. 2 is a front view of the first frame. Fig. 3 is a front view of the adsorption filter. Fig. 4 is an enlarged view of a portion of the strip. Fig. 5 is an enlarged view of a portion of the adsorption filter.

[0008] <One embodiment of the adsorption filter> An embodiment of the adsorption filter will be described below. Note that the drawings may show components enlarged to facilitate understanding. The dimensional ratios of the components may differ from those in the actual drawings or from those in other drawings.

[0009] (Overall Configuration of the Device) As shown in Figure 1, the device 10 includes a first frame 20, a second frame 30, and an adsorption filter 40. The device 10 has a generally cylindrical outer shape extending along a central axis CA. That is, the first frame 20, the second frame 30, and the adsorption filter 40 all have generally cylindrical outer shapes with roughly the same diameter. Note that, hereinafter, a specific direction parallel to the central axis CA is referred to as the positive direction PD. Of the directions parallel to the central axis CA, the direction opposite to the positive direction PD is referred to as the negative direction ND.

[0010] The first frame 20 includes the end of the device 10 on the negative direction ND side. The first frame 20 is generally cylindrical. The central axis of the first frame 20 coincides with the central axis CA of the device 10. The first frame 20 has a plurality of through holes that penetrate from the end on the negative direction ND side to the end on the positive direction PD side. Specifically, the first frame 20 includes a cylindrical body C and three partition walls W. Each partition wall W extends from the inner surface of the body C toward the central axis CA. The partition walls W are arranged circumferentially around the central axis CA at a predetermined interval. The ends of the partition walls W on the central axis CA side are connected to each other. As a result, the first frame 20 has a plurality of through holes, namely, a first flow passage 21, a second flow passage 22, and a third flow passage 23. As shown in FIG. 2 , when viewed in a direction along the central axis CA of the first frame 20, each flow passage is generally fan-shaped. The first flow passage 21 is the through hole with the largest spatial volume. The central angle of the fan shape of the first flow passage 21 is greater than 180 degrees. The second flow passage 22 is a through hole adjacent to the first flow passage 21 in the counterclockwise direction when viewed in the negative direction ND. The third flow passage 23 is a through hole adjacent to the second flow passage 22 in the counterclockwise direction and adjacent to the first flow passage 21 in the clockwise direction when viewed in the negative direction ND. In other words, the third flow passage 23 is located between the first flow passage 21 and the second flow passage 22. The central angle of the fan shape of the third flow passage 23 is approximately the same as the central angle of the fan shape of the second flow passage 22.

[0011] As shown in FIG. 1 , the second frame 30 includes the end of the device 10 on the positive direction PD side. Although not shown, the shape of the second frame 30 is similar to that of the first frame 20. That is, the second frame 30 is substantially cylindrical. The central axis of the second frame 30 coincides with the central axis CA of the device 10. The second frame 30 has a plurality of through-holes that penetrate from the end on the negative direction ND side to the end on the positive direction PD side. Specifically, the second frame 30 has a fourth flow path, a fifth flow path, and a sixth flow path as the plurality of through-holes.

[0012] The size and shape of the opening of the fourth flow passage on the negative direction ND side are the same as the size and shape of the opening of the first flow passage 21 on the positive direction PD side. The opening of the fourth flow passage faces the opening of the first flow passage 21 via the adsorption filter 40. That is, the first flow passage 21 and the fourth flow passage are aligned in a direction parallel to the central axis CA with the adsorption filter 40 interposed therebetween.

[0013] The size and shape of the opening on the negative direction ND side of the fifth flow passage are the same as the size and shape of the opening on the positive direction PD side of the second flow passage 22. The opening of the fifth flow passage faces the opening of the second flow passage 22 via the adsorption filter 40. That is, the second flow passage 22 and the fifth flow passage are aligned in a direction parallel to the central axis CA with the adsorption filter 40 interposed therebetween.

[0014] The size and shape of the opening on the negative direction ND side of the sixth flow passage are the same as the size and shape of the opening on the positive direction PD side of the third flow passage 23. The opening of the sixth flow passage faces the opening of the third flow passage 23 via the adsorption filter 40. That is, the third flow passage 23 and the sixth flow passage are aligned in a direction parallel to the central axis CA with the adsorption filter 40 interposed therebetween.

[0015] The adsorption filter 40 is a carrier that carries an adsorbent capable of adsorbing a specific substance. In this embodiment, the specific substance is a vaporized organic solvent. The adsorbent is, for example, a catalyst capable of adsorbing the organic solvent. As shown in FIG. 1 , the adsorption filter 40 has an overall substantially cylindrical outer shape. The adsorption filter 40 is located between the first frame 20 and the second frame 30. The central axis of the adsorption filter 40 coincides with the central axis CA of the device 10. A first end surface 41 of the adsorption filter 40 faces the first frame 20. A second end surface 42 of the adsorption filter 40 faces the second frame 30.

[0016] The first frame 20 is attached to the adsorption filter 40 so that the opening edges of the through holes on the positive direction PD side face the first end face 41 of the adsorption filter 40 at a distance. The second frame 30 is attached to the adsorption filter 40 so that the opening edges of the through holes on the negative direction ND side face the second end face 42 of the adsorption filter 40 at a distance. A sealant (not shown) is interposed between the outer edge of the first end face 41 of the adsorption filter 40 and the outer edge of the end face of the first frame 20 on the positive direction PD side. Similarly, a sealant (not shown) is interposed between the outer edge of the second end face 42 of the adsorption filter 40 and the outer edge of the end face of the second frame 30 on the negative direction ND side. This prevents gas flowing through the first frame 20, the adsorption filter 40, and the second frame 30 from leaking out of the device 10.

[0017] Although not shown, the adsorption filter 40 is connected to a drive source such as an electric motor via a power transmission mechanism such as a gear mechanism and rollers. Based on the power from the drive source, the adsorption filter 40 can rotate relative to the first frame 20 and the second frame 30 about the central axis CA at a speed of 5 revolutions per minute or more and 15 revolutions per minute or less. The direction of rotation is clockwise when viewed facing the forward direction PD.

[0018] As shown in FIG. 3 , the adsorption filter 40 has a so-called honeycomb structure. That is, the adsorption filter 40 has multiple gaps G therein. The multiple gaps G are connected from the first end face 41 to the second end face 42. Therefore, air passing through each flow passage of the first frame 20 and the second frame 30 can pass between the first end face 41 and the second end face 42 of the adsorption filter 40. Note that in FIG. 3 , the honeycomb structure of the first end face 41 is partially omitted. Furthermore, the honeycomb structure referred to here includes a structure in which multiple three-dimensional structures of one or more types are arranged side by side. A more detailed configuration of the adsorption filter 40 will be described later.

[0019] (Connection with Drying Oven) The device 10 is used while connected to a drying oven. The drying oven is a device for drying a coating material, for example, after applying the coating material to electronic components. At this time, the gas discharged from the drying chamber R of the drying oven contains vaporized organic solvents, etc.

[0020] Specifically, as shown in FIG. 1 , the drying oven has a first duct D1 to a sixth duct D6. The first duct D1 is connected to the negative (ND) side of the first flow passage 21 in the first frame 20. The second duct D2 is connected to the negative (ND) side of the second flow passage 22 in the first frame 20. The third duct D3 is connected to the negative (ND) side of the third flow passage 23 in the first frame 20. The fourth duct D4 is connected to the positive (PD) side of the fourth flow passage in the second frame 30. The fifth duct D5 is connected to the positive (PD) side of the fifth flow passage in the second frame 30. The sixth duct D6 is connected to the positive (PD) side of the sixth flow passage in the second frame 30.

[0021] Note that FIG. 1 shows a schematic diagram of the connection relationship between each frame and each duct. In reality, the first duct D1 is connected to the opening on the negative direction ND side of the first flow passage 21 via a cover, an adapter, a sealant, or the like. Therefore, there is no gap between the first duct D1 and the opening on the negative direction ND side of the first flow passage 21. In other words, when gas flows from the first duct D1 to the first flow passage 21, gas leakage from between the two is prevented. This also applies to the connection relationship between the other ducts and flow passages. Any known configuration can be appropriately used for these connection configurations.

[0022] The drying furnace includes a first fan B1, a second fan B2, and a heater HE. The first fan B1 blows gas containing an organic solvent exhausted from the drying chamber R into a first duct D1. The gas blown into the first duct D1 flows through the first duct D1 toward the forward direction PD side. Accordingly, the gas passes through the adsorption filter 40 from the reverse direction ND side of the first duct D1 via the first flow passage 21. The organic solvent components contained in the gas are adsorbed by the adsorbent as they pass through the adsorption filter 40. The gas from which the organic solvent components have been removed is then exhausted to the fourth duct D4 via the fourth flow passage of the second frame 30.

[0023] The second fan B2 blows air that does not contain organic solvents into the second duct D2. The gas supplied to the second duct D2 flows through the second duct D2 toward the forward direction PD. Therefore, the air passes from the negative direction ND side of the second duct D2 through the second flow passage 22, the adsorption filter 40, the fifth flow passage, and the fifth duct D5, in that order. Note that the air absorbs heat from the adsorption filter 40 as it passes through the gap G of the adsorption filter 40. Therefore, the temperature of the air flowing through the fifth flow passage and the fifth duct D5 rises to approximately 60°C.

[0024] The heater HE is supplied with air circulating through the fifth duct D5. The heater HE heats the supplied gas, turning it into hot air at approximately 200°C. This hot air is then supplied from the heater HE to the sixth duct D6. The hot air then passes through the sixth duct D6, the sixth flow passage of the second frame 30, and the interior of the adsorption filter 40. At this time, the portion of the adsorption filter 40 facing the sixth flow passage of the second frame 30 is exposed to the hot air flowing through the sixth flow passage. The adsorption filter 40 is also rotating relative to the second frame 30. Therefore, the portion of the adsorption filter 40 facing the sixth flow passage of the second frame 30 is in a state in which the organic solvent contained in the gas from the first duct D1 is adsorbed. Therefore, the hot air desorbs the organic solvent adsorbed in the adsorbent from the adsorbent. The hot air containing the desorbed organic solvent is supplied to a predetermined recovery device via the third flow passage 23 and the third duct D3. In this way, the device 10 can concentrate and recover the organic solvent from the gas exhausted from the drying chamber R.

[0025] (Regarding the adsorbent) In the following, the direction parallel to the central axis CA of the adsorption filter 40 is referred to as the axial direction AD. The central axis of the adsorption filter 40 coincides with the central axis CA of the device 10. Therefore, in the following, the central axis of the adsorption filter 40 and the central axis CA of the device 10 will not be distinguished from each other. Furthermore, the direction perpendicular to the central axis CA of the adsorption filter 40 is referred to as the radial direction RD. Within the radial direction RD, the direction toward the central axis CA is referred to as the inward direction RD1, and the direction opposite to the inward direction RD1 is referred to as the outward direction RD2. Furthermore, the direction along the circumference centered on the central axis CA is referred to as the circumferential direction CD. Note that in Figures 4 and 5, a portion of the adsorption filter 40 is shown enlarged, and therefore the circumferential direction CD is shown as an approximation to a straight line.

[0026] As shown in Figure 3, the adsorption filter 40 includes a core material 43. The core material 43 is substantially cylindrical. The central axis of the core material 43 coincides with the central axis CA of the adsorption filter 40. The dimension of the core material 43 in the axial direction AD is substantially the same as the dimension 40T of the adsorption filter 40 in the axial direction AD. The diameter of the core material 43 is sufficiently small compared to the diameter of the adsorption filter 40. Note that the core material 43 is exaggerated in size in Figure 3.

[0027] In this embodiment, as shown in Figure 4, the adsorption filter 40 has a first band 44A and a second band 44B. Each band supports an adsorbent on its surface. Each band is made of a metal, such as iron.

[0028] The first band 44A has a shape in which concave and convex portions are repeated in the circumferential direction CD. In other words, the first band 44A has a shape in which convex portions in the inward direction RD1 and convex portions in the outward direction RD2 are alternately repeated in the circumferential direction CD. In this embodiment, when viewed in the axial direction AD, the first band 44A has a triangular wave shape. Specifically, a reference line RL is assumed to pass through the center of the height dimension H of the first band 44A in the radial direction RD and extend in the circumferential direction CD. In this case, the first band 44A has alternating vertices P located on the outward direction RD2 side and vertices P located on the inward direction RD1 side with respect to the reference line RL. When viewed in a plan view along the axial direction AD, the shape of the first band 44A between the vertex P on the outward direction RD2 side and the vertex P on the inward direction RD1 side is linear. Furthermore, the shortest distance from the reference line RL to the vertex P located on the outward direction RD2 side of the reference line RL is approximately the same as the shortest distance from the reference line RL to the vertex P located on the inward direction RD1 side of the reference line RL.

[0029] In the circumferential direction CD, the distance LP between the apexes P of the shape convex in the outward direction RD2 is 2 mm or more and 5 mm or less. In the circumferential direction CD, the distance between the apexes P of the shape convex in the inward direction RD1 is substantially the same as the distance LP. The height dimension H of the first band-shaped body 44A in the radial direction RD is 1 mm or more and 3 mm or less. The dimension of the first band-shaped body 44A in the axial direction AD is 5 mm or more and 50 mm or less.

[0030] The second band 44B is generally flat. The second band 44B is connected to the first band 44A at its vertex P on the outward direction RD2 side by various adhesive materials. Therefore, a gap G is formed between the first band 44A and the second band 44B. The dimension 44T in the axial direction AD of the second band 44B is the same as the dimension 44T in the axial direction AD of the first band 44A.

[0031] As shown in Figure 3, each strip is wound around a core material 43 around a specific central axis. That is, each strip is wound so that two or more layers overlap in the radial direction RD. Specifically, each strip overlaps several hundred to several thousand layers in the radial direction RD. The maximum dimension MD of the adsorption filter 40 in the radial direction RD is 2000 mm or less. The first strip 44A and the second strip 44B overlapping in the radial direction RD define multiple gaps G aligned in the circumferential direction CD. The shape of each strip, the size of the gaps G, the winding method, and the like are determined by a simulation process described below.

[0032] As shown in FIG. 1 , each strip is wound around two or more times in the axial direction AD. Specifically, each strip is wound around several to several tens of times in the axial direction AD. The axial dimension 40T of the adsorption filter 40 is 120 mm or more and 400 mm or less. Therefore, as shown in FIG. 5 , multiple gaps G in each strip are aligned in the axial direction AD. In FIG. 5 , the axial direction AD is perpendicular to the paper surface. The multiple gaps G aligned in the axial direction AD are connected to each other in the axial direction AD. When viewed in the axial direction AD, the positions of the gaps G aligned in the axial direction AD are offset in the circumferential direction CD. Specifically, in two portions of the first strip 44A adjacent to each other in the axial direction AD, the vertices P of the convex shapes extending outward in the outward direction RD2 are offset in the circumferential direction CD. Because the position of the gap G is shifted in this manner, when viewed in a plane facing the axial direction AD, the area of ​​the region where two adjacent gaps G in the axial direction AD overlap is smaller than the area of ​​each of the two gaps G.

[0033] (Method of Manufacturing the Adsorption Filter) Next, a description will be given of a method of manufacturing the adsorption filter 40. The method of manufacturing the adsorption filter 40 includes a simulation step, a preparation step, and a molding step.

[0034] In the simulation process, the opening area and other parameters of the gap G defined by the band-shaped body are determined by simulation using the finite element method. Specifically, the gap G is modeled to have a triangular shape in a plan view along the central axis CA. This simulation revealed that reducing the opening area of ​​the gap G increases the Reynolds number of the gas passing through the gap G. Specifically, the air flow begins to become turbulent when the Reynolds number exceeds approximately 2300. This becomes particularly noticeable at a Reynolds number of approximately 4000 or higher, resulting in so-called turbulent flow. Therefore, by shifting the position of the gap G or adjusting the amount of adsorbent carried by the adsorption filter 40, the area of ​​the overlapping region between two adjacent gaps G in the axial direction AD can be reduced, thereby increasing the Reynolds number. In other words, by disturbing the flow of air flowing through the gap G, the contact time between the air and the adsorbent can be extended.

[0035] Next, a preparation process is performed. In the preparation process, a core material 43 and a strip are prepared. The core material 43 is cylindrical. The strip here has the same configuration as described above. Next, a molding process is performed. In the molding process, the strip is wound around the central axis CA of the core material 43 so that the strip defines multiple gaps G aligned in the circumferential direction CD. In addition, in the molding process, the strip is wound so that the multiple gaps G are aligned in the axial direction AD and are connected to each other in the axial direction AD. At this time, when viewed in the axial direction AD, the positions of the gaps G aligned in the axial direction AD are shifted in the circumferential direction CD. In this way, one layer of the strip is formed by winding the strip a predetermined number of times in the axial direction AD. As a result, one layer of the strip is formed into a cylindrical shape. Then, the molding process is repeated so that the layers of the strip overlap in the radial direction RD.

[0036] More specifically, each strip is pulled out in a strip-like state from a predetermined case or the like. At this time, the second strip 44B is connected to the apex P of the first strip 44A on the outward direction RD2 side by an adhesive. Then, after fixing the ends of each strip to the core material 43, the core material 43 is rotated about the central axis CA, thereby winding each strip around the core material 43. At this time, each strip is moved relative to the core material 43 in one direction along the axial direction AD, thereby winding each strip in a spiral on the outer circumferential surface of the core material 43. Furthermore, each strip is wound so that no gaps are formed between adjacent strips in the axial direction AD. Then, by winding the strips around the core material 43 by the dimension in the axial direction AD, a single cylindrical layer of strips consisting of the first strip 44A and the second strip 44B is formed. Next, the strips are wound spirally over the first layer while moving them in the opposite direction to the first layer, forming a second layer. That is, the strips forming the first layer and the strips forming the second layer are continuous. This forming process is repeated as many times as necessary to manufacture the adsorption filter 40.

[0037] (Effects of the Present Embodiment) (1) In the above embodiment, a configuration in which each strip is wound two or more times in the radial direction RD is modeled based on the above-described simulation. As a result, adjacent strips in the circumferential direction CD define gaps G. Furthermore, because the strips are also wound spirally, the gaps G are connected in the axial direction AD. Furthermore, when viewed in the axial direction AD, the positions of the gaps G aligned in the axial direction AD are shifted in the circumferential direction CD. This increases the Reynolds number of the gas flowing through the gaps G. In other words, turbulence in the gas flow makes it difficult for the gas to travel straight from the first end face 41 side to the second end face 42 side of the adsorption filter 40. As a result, the gas is in contact with the surface of each strip for a longer period of time, making it easier for the adsorbent to adsorb the adsorbed substances contained in the air.

[0038] (2) In the above embodiment, the first band 44A has a triangular wave shape. With this shape, the gaps G can be defined by the shape of the band itself, without having to wind the band in a complex manner. By shifting the triangular wave shape of the band in the circumferential direction CD, the positions of the gaps G aligned in the axial direction AD can be easily shifted in the circumferential direction CD.

[0039] (3) In the above embodiment, in two portions of the second band-shaped body 44B adjacent to each other in the axial direction AD, the vertices P of the shapes convex in the outward direction RD2 are offset in the circumferential direction CD. This reliably achieves a state in which the positions of the gaps G aligned in the axial direction AD are offset when viewed in the axial direction AD.

[0040] (4) In the above embodiment, the distance LP between the vertices P of the second band 44B in the circumferential direction CD that is convex in the outward direction RD2 is 2 mm or more and 5 mm or less. If the distance LP between the vertices P is within this range, the flow of gas is not easily obstructed, and the gas is kept in contact with the surface of the band for a sufficient period of time.

[0041] (5) In the above embodiment, the maximum dimension MD of the adsorption filter 40 in the radial direction RD is 2000 mm or less. The dimension 40T of the adsorption filter 40 in the axial direction AD is 120 mm or more and 400 mm or less. The dimension 44T of the strip in the axial direction AD is 5 mm or more and 50 mm or less. When the maximum dimension MD of the adsorption filter 40 is 2000 mm or less, if the dimension 40T of the adsorption filter 40 in the axial direction AD is smaller than 120 mm, it is difficult to ensure sufficient contact between the adsorbent and the air passing through the adsorption filter 40. Furthermore, if the dimension 40T of the adsorption filter 40 in the axial direction AD is 400 mm or less, sufficient contact between the adsorbent and the air is ensured. If the dimension 40T of the strip in the axial direction AD is smaller than 5 mm, the gap G is likely to become small. In other words, there is a risk of impeding the flow of gas. If the width of the strip is greater than 50 mm, gas tends to travel in a straight line, which shortens the time the gas is in contact with the surface of the strip.

[0042] (6) In the above embodiment, the adsorption filter 40 is formed layer by layer. If the strip were wound randomly, the size of the gaps G would likely vary depending on the location on the adsorption filter 40. In this case, gas would likely flow through areas where the gaps G are large or where the gaps G are connected linearly. Conversely, gas would not likely flow through areas where the gaps G are small or where the gaps G are blocked in the axial direction AD. This makes it difficult to efficiently collect adsorbed substances.

[0043] By forming the adsorption filter 40 layer by layer, the gap G is likely to be partitioned into approximately uniform sizes in the circumferential direction CD, the radial direction RD, and the axial direction AD. This makes it difficult for the gas flow path in the adsorption filter 40 to become uneven, making it easier to efficiently collect the adsorbed substances.

[0044] <Modifications> The above embodiment and the following modifications can be implemented in combination with each other within the scope of technical compatibility.

[0045] The shape of the device 10 is not limited to the example of the above embodiment. The shapes of the first frame 20, the second frame 30, and the adsorption filter 40 can also be changed appropriately to match the shape of the device 10.

[0046] The type of adsorbent contained in the adsorption filter 40 is not limited to that described in the above embodiment. That is, the adsorbed substance is not limited to organic solvents. For example, the type of adsorbent may be changed so that the adsorption filter 40 can be used as a deodorizing filter.

[0047] The adsorption filter 40 may have only one type of band. For example, the adsorption filter 40 may have only the first band 44A or only the second band 44B. Even in such cases, it is sufficient that the gap G can be defined by winding the band. Furthermore, the adsorption filter 40 may have three or more types of bands with different shapes.

[0048] The unevenness of the first band-shaped body 44A does not have to be triangular wave-shaped. For example, the portion of the first band-shaped body 44A that is convex in the outward direction RD2 relative to the reference line RL and the portion that is convex in the inward direction RD1 relative to the reference line RL may be rectangular. In other words, the first band-shaped body 44A may have a rectangular wave-like shape.

[0049] In two portions of the first band-shaped body 44A adjacent to each other in the axial direction AD, the vertices P of the shape convex in the outward direction RD2 do not have to be offset in the circumferential direction CD. Even if the positions of the vertices P coincide with the axial direction AD, for example, if the spacing between the vertices P of the first band-shaped body 44A is partially different, the positions of the gaps G aligned in the axial direction AD can be offset in the circumferential direction CD.

[0050] Furthermore, the distance LP between the vertices P of the surfaces that are convex in the outward direction RD2 does not have to be constant and may vary from place to place. In this case, the vertices P of the first bands 44A that are adjacent in the axial direction AD may be constant in some places. However, if there are some places where the vertices P of the adjacent first bands 44A are offset in the circumferential direction CD, the gap G will be offset in the circumferential direction CD.

[0051] The dimensions of the adsorption filter 40 and the strip are not limited to those of the above embodiment and may be changed as appropriate depending on the application and type of the adsorption filter 40. When winding the strip, a single continuous strip may be wound over multiple layers, or, for example, a different strip may be wound for each layer.

[0052] The manufacturing method of the adsorption filter 40 is not limited to the example of the above embodiment. By randomly winding the strip around the core material 43, gaps G are likely to be formed, and the positions of the gaps G aligned in the axial direction AD are likely to be shifted in the circumferential direction CD. In other words, the time that the gas is in contact with the surface of the strip increases.

[0053] <Supplementary Notes> The technical ideas that can be understood from the above embodiments and modified examples will be described below. [1] An adsorption filter comprising a band-shaped body carrying an adsorbent capable of adsorbing a specific substance and wound around a specific central axis, the band-shaped body being wound so as to overlap in two or more layers in a radial direction perpendicular to the central axis and so as to be lined up in two or more rounds in an axial direction parallel to the central axis, the band-shaped body overlapping in the radial direction defines a plurality of gaps lined up in a circumferential direction around the central axis, the plurality of gaps being lined up in the axial direction, and the plurality of gaps lined up in the axial direction are connected to each other in the axial direction, and when viewed in the axial direction, the positions of the gaps lined up in the axial direction are shifted in the circumferential direction, and the area of ​​a region where two axially adjacent gaps overlap is smaller than the area of ​​each of the two gaps.

[0054] [2] The adsorption filter described in [1] has a plurality of types of band-shaped bodies with different shapes, and at least one of the plurality of types of band-shaped bodies has a shape in which unevenness is repeated in the circumferential direction.

[0055] [3] When the radial direction is defined as the direction toward the central axis as the inward direction and the direction opposite to the inward direction as the outward direction, the band-shaped body has a shape in which the inwardly convex shape and the outwardly convex shape are alternately repeated in the circumferential direction, and in two parts of the band-shaped body adjacent to each other in the axial direction, the vertices of the outwardly convex shape are offset in the circumferential direction. [2] An adsorption filter.

[0056] [4] The adsorption filter according to [3], wherein the spacing between the vertices of the outwardly convex surface shape in the circumferential direction is 2 mm or more and 5 mm or less. [5] The adsorption filter according to any one of [1] to [4], wherein the maximum dimension in the radial direction is 2000 mm or less, the dimension in the axial direction is 120 mm or more and 400 mm or less, and the dimension in the axial direction of the band-shaped body is 5 mm or more and 50 mm or less.

[0057] 10...Device CA...Central axis 20...First frame 30...Second frame 40...Absorption filter 43...Core material 44A...First band-shaped body P...Vertex 44B...Second band-shaped body G...Gap AD...Axial direction CD...Circumferential direction RD...Radial direction

Claims

1. An adsorption filter comprising a strip-shaped body carrying an adsorbent capable of adsorbing a specific substance and wound around a specific central axis, wherein the strip-shaped body is wound so as to overlap in two or more layers in a radial direction perpendicular to the central axis, and is wound so as to be lined up in two or more rounds in an axial direction parallel to the central axis, the strip-shaped body overlapping in the radial direction defines a plurality of gaps lined up in a circumferential direction around the central axis, the plurality of gaps lined up in the axial direction, and the plurality of gaps lined up in the axial direction are connected to each other in the axial direction, and when viewed in the axial direction, the positions of the gaps lined up in the axial direction are shifted in the circumferential direction, and the area of ​​the region where two adjacent gaps in the axial direction overlap is smaller than the area of ​​each of the two gaps.

2. The adsorption filter according to claim 1, wherein the bands are of a plurality of types with different shapes, and at least one of the plurality of types of bands has a shape in which recesses and projections are repeated in the circumferential direction.

3. An adsorption filter as described in claim 2, wherein, when the radial direction is defined as the direction toward the central axis as the inward direction and the direction opposite to the inward direction as the outward direction, the band-shaped body has a shape in which the inwardly convex shape and the outwardly convex shape are alternately repeated in the circumferential direction, and in two parts of the band-shaped body adjacent to each other in the axial direction, the vertices of the outwardly convex shape are offset in the circumferential direction.

4. The adsorption filter according to claim 3, wherein the distance between vertices of the outwardly convex shape in the circumferential direction is 2 mm or more and 5 mm or less.

5. An adsorption filter according to any one of claims 1 to 4, wherein the maximum radial dimension is 2000 mm or less, the axial dimension is 120 mm or more and 400 mm or less, and the axial dimension of the strip is 5 mm or more and 50 mm or less.

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