Filter assembly and air filter provided with the same

Abstract

The present application provides a filter assembly capable of preferably maintaining a pleat spacing while suppressing a rise in pressure loss and an air filter provided with the filter assembly. The filter assembly is provided with: a filter medium having folds alternately repeated on an upstream side and a downstream side of an air flow by a pleating process, at least one pair of upstream side ventilation surfaces opposite each other with the downstream side folds interposed and for the air flow to flow in, and at least one pair of downstream side ventilation surfaces opposite each other with the upstream side folds interposed and for the air flow to flow out; and a plurality of spacing maintaining members formed on each of the upstream side ventilation surfaces and the downstream side ventilation surfaces in order to maintain a spacing between each pair of the upstream side ventilation surfaces and a spacing between each pair of the downstream side ventilation surfaces, the plurality of spacing maintaining members formed on the upstream side ventilation surfaces being intermittently formed in a direction orthogonal to the folds, and at least one spacing maintaining member formed on one of the upstream side ventilation surfaces of the pair of the upstream side ventilation surfaces and at least one spacing maintaining member formed on the other of the upstream side ventilation surfaces of the pair of the upstream side ventilation surfaces contacting at two or more places.

Description

Technical Field

[0001] The present invention relates to a filter assembly having pleated filter media and an air filter having the filter assembly. Background Technology

[0002] Previously, a filter assembly was known in which spacer members were formed on a pleated filter media to uniformly maintain the pleat spacing. For example, Patent Document 1 discloses a filter assembly in which the spacing is maintained by bringing opposing spacer members into contact with each other.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-062610 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] While the spacer retainers serve to maintain the pleat spacing of the filter assembly, they increase pressure loss because they cover the ventilation surface of the filter media. Furthermore, if the positional and dimensional accuracy required during the formation and pleating process to ensure contact between the spacer retainers is not achieved, the spacer retainers will not contact each other, resulting in a risk of uneven pleat spacing.

[0008] The present invention was made in view of the following circumstances, and its object is to provide a filter assembly capable of better maintaining the pleat spacing while suppressing the increase of pressure loss, and an air filter having the filter assembly.

[0009] Solution for solving the problem

[0010] The present invention provides a filter assembly comprising: a filter material for capturing fine particles in a gas, the filter material having alternating pleats on an upstream and downstream side of an airflow by pleating; at least one pair of upstream ventilation surfaces opposite each other across the downstream pleats and allowing the airflow to flow in; and at least one pair of downstream ventilation surfaces opposite each other across the upstream pleats and allowing the airflow to flow out; and a plurality of spacer members formed on each of the upstream and downstream ventilation surfaces to maintain the spacer between each pair of upstream ventilation surfaces and the spacer between each pair of downstream ventilation surfaces, the plurality of spacer members formed on the upstream ventilation surfaces being intermittently formed in a direction orthogonal to the pleats; at least one spacer member formed on one of the upstream ventilation surfaces being in contact with at least one spacer member formed on the other of the pair of upstream ventilation surfaces at two or more locations.

[0011] The effects of the invention

[0012] In the filter assembly of the present invention and the air filter having the filter assembly, the pleat spacing can be better maintained while suppressing the increase in pressure loss. Attached Figure Description

[0013] Figure 1 This is a perspective view of an air filter showing one embodiment of the air filter of the present invention.

[0014] Figure 2 This is a diagram showing a portion of the folded filter assembly as viewed from the direction extending along the creases of the folds.

[0015] Figure 3 yes Figure 2 A magnified view of a portion of the image.

[0016] Figure 4 This is a partially enlarged view of the filter assembly as a first modified example.

[0017] Figure 5 This is a partially enlarged view of the filter assembly as a second variation.

[0018] Figure 6 This is a diagram showing a portion of the filter assembly as a third variation, which is a folded filter assembly, viewed from the direction extending from the crease of the fold.

[0019] Figure 7 This is a diagram showing a portion of the filter assembly as a fourth variation, which is a folded filter assembly, viewed from the direction extending from the crease of the fold. Detailed Implementation

[0020] Embodiments of the filter assembly and air filter of the present invention will be described with reference to the accompanying drawings.

[0021] Figure 1 This is a perspective view of an air filter 1, representing one embodiment of the air filter of the present invention.

[0022] Figure 2 This is a diagram showing a portion of the folded filter assembly 3 as viewed from above, extending along the creases 12 and 13.

[0023] Figure 3 yes Figure 2 A magnified view of a portion of the image.

[0024] The air filter 1 includes a filter assembly 3 and a frame 5. The frame 5 surrounds the filter assembly 3 such that creases 12 and 13 of the filter media 11 are positioned upstream and downstream of the airflow direction (X direction) of the filter media 11. Furthermore, in this embodiment, for convenience, the crease located upstream (-X direction) is referred to as crease 12, and the crease located downstream (+X direction) is referred to as crease 13. The filter assembly 3 includes filter media 11 and a plurality of spacer members 20.

[0025] Filter media 11 is a component for capturing fine particles in a gas. Filter media 11 is used, for example, to remove particles with a diameter of 2.5 μm or less and a concentration of 0.3 mg / m³. 3 The following dust. Filter material 11, for example, has a collection efficiency of over 80% obtained using the counting method, a pressure loss of 79–493 Pa, and a dust retention capacity (dust holding capacity) of 200–800 g / m³. 2 The filter media. In the counting method, the measurement is performed by ventilating air containing any one of the following particles with a particle size of 0.3 μm: atmospheric dust, polyalphaolefin (PAO), or silica. The dust holding capacity is the amount of dust captured by the filter until a predetermined final pressure loss is reached. Alternatively, the filter media 11 can also be, for example, filter media for HEPA (High Efficiency Particulate Air) filters, ULPA (Ultra Low Penetration Air) filters, or filter media for degassing filters.

[0026] The filter media 11 may be a fibrous body composed of glass fibers, organic fibers, or a mixture of these fibers, such as nonwoven fabric or felt. Filter media 11 made of glass fibers may be manufactured, for example, using wet or dry papermaking processes. Filter media 11 made of organic fibers may be manufactured, for example, using spunbond, meltblown, thermal bonding, or chemical bonding methods. Alternatively, the filter media 11 may also be a filter media formed by laminating multiple layers of nonwoven fabric with different collection efficiencies.

[0027] The filter media 11 is pleated into a roughly V-shape by alternating and repeating mountain-shaped and valley-shaped pleats. The pleating process is performed using a reciprocating or rotary pleating machine or the like. The filter media 11 is pleated so that it has mutually parallel pleats 12, 13 on the upstream and downstream sides of the airflow. In addition, the filter media 11 has a pair of ventilation surfaces 14 (ventilation surfaces 14a, 14b) that are continuous via the pleats 12, 13 and opposite each other in the roughly Y direction.

[0028] Specifically, the ventilation surface 14 has at least one pair of upstream ventilation surfaces 15a, 15b and a pair of downstream ventilation surfaces 16a, 16b. The pair of upstream ventilation surfaces 15a, 15b are opposite each other across the downstream fold 13 and are ventilation surfaces 14 for airflow inflow. The pair of downstream ventilation surfaces 16a, 16b are opposite each other across the upstream fold 12 and are ventilation surfaces 14 for airflow outflow. Hereinafter, without distinguishing between the upstream ventilation surfaces 15a, 15b and the downstream ventilation surfaces 16a, 16b, they will simply be referred to as ventilation surface 14.

[0029] The spacer retaining member 20 is a plurality of members that retain the spacer (pleat spacer) between a pair of ventilation surfaces 14 of the filter material 11. The spacer retaining member 20 is intermittently formed on the ventilation surfaces 14 in a direction orthogonal to the direction along the pleats 12, 13 (approximately the X direction). Figure 2 For example, three spaced retaining members 20 are intermittently formed on the ventilation surface 14a.

[0030] At least one spacer retaining member 20 formed on one of a pair of ventilation surfaces 14 contacts at more than two locations with at least one spacer retaining member 20 formed on the other of the pair of ventilation surfaces 14. Specifically, the spacer retaining member 20a formed on the ventilation surface 14b contacts at two contact points 23, 23 with a plurality of adjacent spacer retaining members 20b, 20c formed on the ventilation surface 14a.

[0031] A spacer retaining member 20 formed on one of a pair of ventilation surfaces 14 has an opposing surface 25 facing the spacer retaining member 20 formed on the other of the pair of ventilation surfaces 14. The opposing surface 25 is, for example, a flat top surface of the spacer retaining member 20. Figure 3As shown, the lengths d1 and d2 of the opposing surface 25a of the spacer retaining member 20a formed on the ventilation surface 14b, which contact the opposing surfaces 25b and 25c of the spacer retaining members 20b and 20c formed on the ventilation surface 14a, along the generally X direction, are preferably more than 1% and less than 10% of the length D of the opposing surface 25a along the generally X direction. If it is less than 1%, the contact portion 23 is small, and there is a risk of reduced spacer retention effect. If it is greater than 10%, the size of the spacer retaining member 20 becomes larger, resulting in a larger area covering the ventilation surface 14 and an increase in pressure loss when using the filter.

[0032] Furthermore, the spacing retaining member 20 has different heights (approximately Y-direction length) depending on the fold spacing. Specifically, in Figure 2 In the process, since the fold interval between a pair of ventilation surfaces 14a and 14b increases from crease 12 toward crease 13, the height of the interval retaining member 20 on the crease 12 side is smaller, and the height of the interval retaining member 20 on the crease 13 side is larger.

[0033] The spacer retaining member 20 is made of, for example, a thermoplastic resin called a hot melt adhesive. Examples of such thermoplastic resins include polyamide-based, polyurethane-based, or olefin-based thermoplastic resins. The spacer retaining member 20 is formed, for example, by directly applying a softened hot melt adhesive to the filter media 11 in a generally X direction using a spray gun filled with the hot melt adhesive. Alternatively, in addition to direct application, the spacer retaining member 20 may also be formed, for example, by bonding a cured hot melt adhesive to the filter media 11. Furthermore, the spacer retaining member 20 may also be made of other materials such as ceramic.

[0034] For such an air filter 1 and filter assembly 3, the spacer retaining member 20 of one of the pair of ventilation surfaces 14 contacts the spacer retaining member 20 of the other of the pair of ventilation surfaces 14 at two points. Therefore, compared to the case where they only contact at one point, the filter assembly 3 is more likely to maintain the pleated spacing. That is, when the spacer retaining member 20 contacts only at one point, for example, it is possible that the positions of the spacer retaining members 20 respectively disposed on the pair of ventilation surfaces 14 may deviate from the manufacturing error and not contact each other. In this case, the pleated spacing is not maintained, and there is a risk of reduced filter efficiency.

[0035] In contrast, in the air filter 1 and filter assembly 3 of this embodiment, since the spacer retaining members 20 are in contact at two points, the opposing spacer retaining members 20 can reliably contact each other and are supported at both points. Furthermore, since friction occurs at the contact points 23, the spacer retaining members 20 are less likely to shift off from each other. Therefore, such a filter assembly 3 and air filter 1 can better maintain the pleat spacing while suppressing the increase in pressure loss.

[0036] Several embodiments of the present invention have been described, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are also included in the scope of the technical solutions described in the claims and their equivalents.

[0037] For example, in the example of filter assembly 3, an example is illustrated where a spacer retaining member 20 formed on one of a pair of ventilation surfaces 14 contacts each of a plurality of adjacent spacer retaining members 20 formed on the other of the pair of ventilation surfaces 14 at one location. However, a spacer retaining member 20 formed on one of the pair of ventilation surfaces 14 may also contact a spacer retaining member 20 formed on the other of the pair of ventilation surfaces 14 at multiple locations. For example, as... Figure 4 As shown in the first variation, a spacer retaining member 20d formed on another ventilation surface 14d of a pair of ventilation surfaces has two protruding shapes 26 protruding in the height direction. The spacer retaining member 20e formed on one of the ventilation surfaces 14e of a pair of ventilation surfaces contacts the two protruding shapes 26 at two points. In addition, there may be more than two contact points 23.

[0038] In addition, such as Figure 5 As shown in the second variation, the spacer retaining member 20f formed on one ventilation surface 14f can be configured as a point-like (approximately hemispherical) shape with a shorter length in the generally X direction, among the spacer retaining members 20 formed on a pair of ventilation surfaces 14f, 14g. In this case, the spacer retaining member 20g formed on the other ventilation surface 14g contacts two or more adjacent opposing spacer retaining members 20f at more than two points. Figure 4 , Figure 5As with the filter assembly, as long as the spacer retaining members 20e, 20g of one ventilation surface 14e, 14g formed in a pair of ventilation surfaces 14 are supported at two places by at least one spacer retaining member 20d, 20f formed in the other ventilation surface 14d, 14f, even if the spacer retaining members 20d, 20f formed in the other ventilation surface 14d, 14f are supported in one place, it can be included in the protection scope of the filter assembly of the present invention.

[0039] Furthermore, an example is described in which the spacer retaining member 20 is intermittently formed in the generally X direction on both the upstream ventilation surfaces 15a and 15b and the downstream ventilation surfaces 16a and 16b in the filter assembly 3. However, on the downstream ventilation surfaces 16a and 16b, the spacer retaining member 20 may be formed continuously in the generally X direction.

[0040] Here, Figure 6 This is a view showing a portion of the filter assembly 103, which is a third variation and is folded, viewed from the direction extending along the crease of the fold. Furthermore, in Figure 6 and Figure 7 In the accompanying drawings, the same reference numerals are used for structures and parts corresponding to filter assembly 3, and repeated descriptions are omitted.

[0041] The filter assembly 103 differs from the filter assembly 3 in that the spacer retaining members 120b formed on the downstream ventilation surfaces 116a, 116b are formed continuously rather than intermittently in the generally X direction. That is, adjacent spacer retaining members 120b are formed in close contact in the generally X direction without forming gaps.

[0042] For example, when continuous ventilation is performed on the filter assembly 103, there is a risk that the internal structure may change even if there is no change in the appearance of the filter assembly 103. For example, there is a risk that the pair of upstream ventilation surfaces 115a, 115b of the filter assembly 103 may expand towards the outflow side due to the inflowing airflow, thereby increasing the fold spacing between the pair of upstream ventilation surfaces 115a, 115b.

[0043] Therefore, the filter assembly 103 is formed with spacer members 120a and 120b in a manner that increases the strength of the filter media 11 while maintaining the advantage of suppressing pressure loss rise, as is the case with the filter assembly 3. Specifically, the spacer members 120a formed on the upstream ventilation surfaces 115a and 115b are formed intermittently in the generally X direction, while the spacer members 120b formed on the downstream ventilation surfaces 116a and 116b are formed continuously in the generally X direction. The spacer members 120b contact each other from the upstream side toward the downstream side at the raised portion 121 relative to the downstream ventilation surfaces 116a and 116b, with the opposing surface 125 of the opposite spacer member 120b.

[0044] Therefore, while ensuring the ventilation area, the expansion of the pair of upstream ventilation surfaces 115a, 115b towards the outflow side can be suppressed by the spacer retaining member 120b, thus maintaining the pleat spacing at the start of use. In addition, for the filter assembly 103, due to the increased strength, the stability of its shape during continuous ventilation is also improved, resulting in the suppression of the increase in pressure loss.

[0045] In addition, Figure 6 In the filter assembly 103, an example is shown where a plurality of spaced retaining members 120b are continuously formed in a generally X direction on the downstream ventilation surfaces 116a, 116b. However, as... Figure 7 As shown in the fourth variation of the filter assembly 203, it is also possible that a spacer retaining member 120b extends longitudinally along the approximately X-direction topography of the downstream ventilation surfaces 116a, 116b.

[0046] Explanation of reference numerals in the attached figures

[0047] 1. Air filter; 3. 103. 203. Filter assembly; 5. Frame; 11. Filter media; 12. 13. Crease; 14. Ventilation surface; 20. 120. Spacer retaining member; 23. Contact area; 25. 125. Opposite surface; 26. Protrusion shape.

Claims

1. A filter assembly, wherein, This filter assembly includes: A filter media for capturing fine particles in a gas, the filter media having alternating pleats on the upstream and downstream sides of an airflow, formed by pleating; at least one pair of upstream ventilation surfaces opposite each other across the downstream pleats and allowing the airflow to enter; and at least one pair of downstream ventilation surfaces opposite each other across the upstream pleats and allowing the airflow to exit; and Multiple spacing retaining members are formed on each of the upstream and downstream ventilation surfaces to maintain the spacing between each pair of upstream ventilation surfaces and the spacing between each pair of downstream ventilation surfaces. The plurality of spacer retaining members formed on the upstream ventilation surface are intermittently formed in a direction orthogonal to the crease, and at least one of the spacer retaining members formed on one of the pair of upstream ventilation surfaces contacts at more than two points with at least one of the spacer retaining members formed on the other of the pair of upstream ventilation surfaces.

2. The filter assembly according to claim 1, wherein, The plurality of spacer retaining members formed on the downstream ventilation surface are intermittently formed in a direction orthogonal to the crease, and at least one of the spacer retaining members formed on one of the pair of downstream ventilation surfaces contacts at more than two points with at least one of the spacer retaining members formed on the other of the pair of downstream ventilation surfaces.

3. The filter assembly according to claim 1, wherein, The plurality of spacer members formed on each of the downstream ventilation surfaces are continuously formed in a direction orthogonal to the crease.

4. The filter assembly according to any one of claims 1 to 3, wherein, At least one of the spacer retaining members of one of the pair of upstream ventilation surfaces is in contact with more than two adjacent spacer retaining members of the other of the pair of upstream ventilation surfaces.

5. The filter assembly according to any one of claims 1 to 3, wherein, The plurality of spacer members formed on each of the upstream ventilation surfaces or each of the downstream ventilation surfaces have different heights depending on the spacer set between the pair of upstream ventilation surfaces or the spacer set between the pair of downstream ventilation surfaces.

6. The filter assembly according to any one of claims 1 to 3, wherein, Each of the spacer retaining members formed in one of the pair of upstream ventilation surfaces or one of the pair of downstream ventilation surfaces has an opposing surface relative to each of the spacer retaining members formed in the other of the pair of upstream ventilation surfaces or the other of the pair of downstream ventilation surfaces. The sum of the lengths of the opposing surfaces and the lengths of the spacers formed on the other upstream ventilation surface in one of the pair of upstream ventilation surfaces or the other downstream ventilation surface in one of the pair of downstream ventilation surfaces, along a direction orthogonal to the crease, is more than 1% and less than 10% of the length of the opposing surfaces along a direction orthogonal to the crease.

7. An air filter, characterized in that, This air filter has the following features: The filter assembly according to any one of claims 1 to 6; and A frame that surrounds the filter assembly in such a way that the folds of the filter media of the filter assembly are arranged on the upstream and downstream sides of the airflow flowing through the filter media.

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