JP7075190B2 - Air filter and filter pack - Google Patents

Description

The present invention relates to an air filter and a filter pack.

The air filter includes a filter medium that collects fine particles such as dust floating in the air. A filter medium made of a sheet-like fiber material such as a non-woven fabric is generally pleated and held in a frame in a folded state so as to form a zigzag shape.
In such an air filter, various measures have been taken to keep the pleated spacing constant in order to secure a gas flow path and suppress an increase in pressure loss. For example, the pleats spacing is kept constant by using a spacing member (spacer) provided linearly in a direction orthogonal to the folds of the pleats (Patent Documents 1 and 2). In this technique, the space-holding material is provided at positions facing each other in the two planar parts (extending parts) that form the valley-folded part of the filter medium, and the pleated space is maintained when the filter material is folded. The spacing members come into contact with each other so as to be.

International Publication No. 2010/137085 Japanese Patent No. 5214893

When the wind passes through the air filter of Patent Document 1, the valley-folded portion of the filter medium may be deformed so as to face each other in parallel due to the wind pressure. It was clarified that when the filter medium is deformed in this way, it is difficult for the wind to flow and the pressure loss increases. As the pressure drop increases, more power is required to form the airflow that passes through the air filter.

On the other hand, Patent Document 2 describes an air filter in which the tip of a portion extending to one side of the space holding material extending to both sides of the crease on the downstream side is arranged in the vicinity of the crease on the upstream side. Patent Document 2 describes that the cross-sectional shape of the pleats of the filter medium can be held in a V shape by using such a form of the spacing holding material.
However, in the air filter of Patent Document 2, the tip end portion of the space holding material extending from the crease on the downstream side to the vicinity of the crease on the upstream side is provided in the extending portion on one side, and the extending portion on the other side. Not in contact with. Generally, the pleated filter medium is assembled to a frame body, and when it is used as an air filter, a force is applied in a direction in which the pleated spacing is narrowed so that the pleating spacing is kept uniform. Therefore, when the above force is applied, the mountain-folded portion is deformed so that the gap between the tip portion of the spacing holding material and the extending portion on the other side is closed, and the pleated spacing is not sufficient. May be uniform. If the pleating interval becomes non-uniform, a portion where it is difficult for the airflow to flow locally is generated, and the pressure loss increases.
An object of the present invention is to provide an air filter and a filter pack capable of reducing pressure loss while maintaining the pleated spacing of the filter medium.

One aspect of the present invention is an air filter.
A filter pack having a filter medium that collects fine particles in a gas and is pleated so that mountain folds and valley folds are alternately repeated, and an interval holding material that maintains the pleating interval of the filter medium.
A frame surrounding the filter pack is provided so that the folds of the filter medium are arranged on the upstream side and the downstream side in the air flow direction.
The filter medium is subjected to a force in a direction in which the pleated spacing is narrowed.
The spacing member is formed on the surface of the filter medium along a direction orthogonal to the crease, and is formed on a first extending portion of the filter medium extending to one side with the crease as a boundary. Has a protruding portion and a second protruding portion formed on the second extending portion of the filter medium extending to the other side.
The length of the first protruding portion along the direction orthogonal to the crease is shorter than the length of the second protruding portion.
In the valley-folded portion of the filter medium, the tip of the second protruding portion extending toward the valley-folded crease abuts on the first extending portion of the filter medium, and the second protruding portion is formed. The portion is in contact with the first protruding portion at a position in the middle of the extending direction of the second protruding portion.
The tip portion is located within a length of 80% or less of the distance between two adjacent folds across the second extending portion from the mountain-folded crease.
The first protruding portion is located on the side of the mountain-folded fold and is mountain-folded from the midpoint of the line segment connecting the two adjacent folds with the first extending portion in between. It is characterized in that it is located on the side of the valley fold between the fold and the midpoint .

The position where the second protruding portion and the first protruding portion abut is preferably closer to the mountain-folded crease than to the valley-folded crease.

The space-holding material has the first protrusion on the second side surface opposite to the first side surface of the filter medium in which the first protrusion and the second protrusion are arranged. Further having a third protruding portion and a fourth protruding portion formed so as to be orthogonal to the crease at the same position as the position in the direction in which the crease extends where the protruding portion and the second protruding portion are located. death,
The third protruding portion is formed at a position where the first extending portion is sandwiched between the third protruding portion and the tip portion of the second protruding portion, and the fourth protruding portion is the second. It is preferable that it is formed at a position where the second extending portion is sandwiched between the protruding portion and the protruding portion.

The space-holding material has the first protrusion on the second side surface opposite to the first side surface of the filter medium in which the first protrusion and the second protrusion are arranged. Further having a third protruding portion and a fourth protruding portion formed so as to be orthogonal to the crease at the same position as the position in the direction in which the crease extends where the protruding portion and the second protruding portion are located. death,
The length of the third protruding portion along the direction orthogonal to the crease is preferably shorter than the length of the fourth protruding portion.

Another aspect of the present invention is a filter pack, which is a filter pack.
A filter medium that collects fine particles in the gas and is pleated so that mountain folds and valley folds are repeated alternately.
It has an interval holding material that holds the pleated interval of the filter medium, and has.
The spacing member is formed on the surface of the filter medium along a direction orthogonal to the crease, and is formed on a first extending portion of the filter medium extending to one side with the crease as a boundary. Has a protruding portion and a second protruding portion formed on the second extending portion of the filter medium extending to the other side.
The length of the first protruding portion along the direction orthogonal to the crease is shorter than the length of the second protruding portion.
In the valley-folded portion of the filter media with the filter media folded, the tip of the second protruding portion extending toward the valley-folded crease abuts on the first extending portion. The second protruding portion is in contact with the first protruding portion at a position in the middle of the extending direction of the second protruding portion.
The tip portion is located within a length of 80% or less of the distance between two adjacent folds across the second extending portion from the mountain-folded crease.
The first protruding portion is located on the side of the mountain-folded fold and is mountain-folded from the midpoint of the line segment connecting the two adjacent folds with the first extending portion in between. It is characterized in that it is located on the side of the valley fold between the fold and the midpoint .

According to the present invention, the pressure loss can be reduced while maintaining the pleated spacing of the filter medium.

It is an external perspective view which shows the air filter by an example of this embodiment. (A) is a diagram showing a cross section of a conventional filter pack, and (b) is a diagram showing a cross section of the filter pack of the present embodiment. It is a figure which shows the cross section of the filter pack by a modification. It is a figure which shows the cross section of the filter pack by a modification. It is a figure which shows the cross section which expanded the filter pack shown in FIG. 2 (b).

Hereinafter, the air filter and the filter pack of the present embodiment will be described.

FIG. 1 is an external perspective view showing an air filter 1 according to an example of the present embodiment.
The air filter 1 includes a filter pack 3 and a frame body 5.

FIG. 2B is a diagram showing a cross section of the filter pack 3.
The filter pack 3 has a filter medium 11 and an interval holding material 13.

The filter medium 11 collects fine particles in the gas and is pleated so that mountain folds and valley folds are alternately repeated. The filter medium 11 is used, for example, for removing dust having a particle size of 2.5 μm or less and a concentration of 0.3 mg / m ³ or less, having a collection efficiency of 80% or more by a counting method, a pressure loss of 79 to 493 Pa, and dust retention. In the counting method using a particle having a capacity (dust retention amount) of 200 to 800 g / m ³ , any of atmospheric dust, polyalphaolefin (PAO), and silica particles having a diameter of 0.3 μm is used. The dust holding capacity is the amount of dust collected by the filter before reaching a predetermined final pressure loss. Further, the filter medium 11 may be, for example, a filter medium for a HEPA filter, a filter medium for a ULPA filter, or a filter medium for a gas removal filter.
The filter medium 11 is, for example, a fiber body made of glass fiber, organic fiber, or a mixed fiber of these fibers, and is, for example, a non-woven fabric or felt. The filter medium 11 made of glass fiber is produced, for example, by making paper by a wet method or a dry method. The filter medium 11 made of organic fibers is produced by, for example, a spunbond method, a melt blow method, a thermal bond method, a chemical bond method, or the like. Further, the filter medium 11 may be, for example, a laminate of a plurality of non-woven fabrics having different collection efficiencies.

Since the filter medium 11 is pleated, it has a plurality of mountain-folded creases 10a and valley-folded creases 10b that are parallel to each other. The filter medium 11 has a first extending portion 11a extending to one side with the crease 10b as a boundary, and a second extending portion 11b extending to the other side. The first extending portion 11a and the second extending portion 11b are alternately arranged in the direction in which the pleats are lined up. Pleating is performed using a reciprocating or rotary folding machine.

The spacing member 13 is a member that holds the pleated spacing of the filter media 11. The interval holding material 13 is made of, for example, a thermoplastic resin called a hot melt resin. Examples of the hot melt resin include polyamide-based, urethane-based, olefin-based, and polyolefin-based thermoplastic resins.

The spacing member 13 is formed on the surface of the filter medium 11 along a direction (Y direction) orthogonal to the crease 10a of the filter medium 11. The spacing member 13 has a first protruding portion 14 and a second protruding portion 15. The first protruding portion 14 is formed on the first extending portion 11a. The second protruding portion 15 is formed on the second extending portion 11b. The protruding portions 14 and 15 each project in a direction away from the surface of the filter medium 11.

The length L1 of the first protruding portion 14 along the direction orthogonal to the crease 10a is shorter than the length L2 of the second protruding portion 15. Then, in the state where the filter medium 11 is folded, in the portion of the valley-folded filter medium 11, the tip portion 15a of the second protruding portion 15 extending toward the valley-folded crease 10b is the first extending portion. The second protruding portion 15 is in contact with 11a, and the second protruding portion 15 is in contact with the first protruding portion 14 at a position 15b in the middle of the extending direction of the second protruding portion 15.
In this way, the two protruding portions 14 and 15 are in contact with each other, so that the pleated spacing of the filter medium 11 is maintained. Then, on the crease 10b side (valley side), the tip portion 15a of the second protruding portion 15 is in contact with both the extending portions 11a and 11b forming the valley-folded portion (valley-folded portion) of the filter medium 11. Moreover, since the protruding portions 14 and 15 are in contact with each other on the crease 10a side (mountain side), the distance between the extending portions 11a and 11b is wider on the mountain side than on the valley side. By having such a shape, the extending portions 11a and 11b forming the valley fold portion are difficult to face in parallel due to the air flow passing through the filter medium 11, and maintain a V-shape open from the valley side to the mountain side. It's easy to do. According to the filter medium 11 that maintained the V-shape, it was found that the air flow was easy to flow and the increase in pressure loss was suppressed. In particular, since the tip portion 15a of the second protruding portion 15 is in contact with both the extending portions 11a and 11b, even if a force is applied in a direction in which the pleating interval is narrowed, the two extending portions facing each other The spacing is maintained and the pleated spacing is kept constant. Therefore, it is difficult to generate a portion where the air flow is difficult to flow, and the decrease in pressure loss is suppressed.

On the other hand, in the conventional filter pack 23, as shown in FIG. 2A, the pleats of the filter medium 31 are brought into contact with each other by the spacing members 33 provided in the extending portions 31a and 31b forming the valley folding portions. The interval is maintained. FIG. 2A is a diagram showing a cross section of the conventional filter pack 23. Then, in the example shown in FIG. 2A, the lengths of the spacing members 33 extending on both sides of the creases 30a and 30b are equal, and the airflow passing through the filter medium 31 causes the spacing members 33 to move in the direction of the airflow (X). The extending portions 31a and 31b tend to form a U-shape when they come into contact with each other over a wide range (direction). Therefore, it was found that the air flow is difficult to flow through the filter medium 31 and the pressure loss increases. Here, in the example shown in FIG. 2A, if a part of the space holding material 33 on the valley side is omitted and the length of the space holding material 33 is shortened, the extending portion in which the space holding material 33 is omitted is omitted. Since the portions 31a and 31b are not supported by the spacing member, they tend to bend so as to bulge downstream due to the passage of the air flow. Therefore, it is difficult for the air flow to flow, and the pressure loss tends to increase.
In the examples shown in FIGS. 2 (a) and 2 (b), the air flow flows from above to below.

Further, in the present embodiment, as described above, the first protruding portion 14 is shorter than the second protruding portion 15, and the area where the spacing member 13 contacts the filter medium 11 is reduced. That is, the area of the filter medium 11 that the air flow does not pass through and does not contribute to the collection of fine particles is reduced. Therefore, according to the present embodiment, the effect of reducing the pressure loss can be obtained.

Further, in the present embodiment, as described above, since the V-shape of the filter medium 11 is easily maintained, it is easy to make the pleated spacing larger than the total of the protruding heights of the protruding portions 14 and 15. Therefore, in the present embodiment, it is easy to widen the pleated interval, the number of pleats in the air filter 1 can be reduced, and the amount of the filter medium used in the air filter 1 can be reduced.
On the other hand, in the conventional filter pack 23, as described above, since the filter medium 31 tends to form a U-shape, the pleated spacing is about the same as the total protruding height of the spacing members 33 in contact with each other. Therefore, it is difficult to increase the pleating interval, and it is difficult to reduce the amount of the filter medium used for the air filter.
Generally, when the filter pack is assembled to the frame body 5, a force is applied in a direction in which the pleating spacing is narrowed so that the pleating spacing is kept uniform. Even when this force is received, in the conventional filter pack 23, the spacing members 33 come into contact with each other in a wide range in the direction of the air flow, and the filter medium 31 tends to form a U-shape. On the other hand, in the present embodiment, the filter medium 11 is folded and the pleated spacing is increased because the first protruding portion 14 does not exist and only the second protruding portion 15 exists on the valley side. Even if a force is applied in the narrowing direction, the protruding portions 14 and 15 come into point contact with each other at the portion 15b in the middle of the second protruding portion 15, and the pleated spacing tends to widen.

In the example shown in FIG. 2B, the projecting portions 14 and 15 extend linearly along a direction orthogonal to the crease 10a.
The length L1 of the first protruding portion 14 is, for example, 10 to 40% of the length between the adjacent folds 10a and 10b (hereinafter, also referred to as the fold width). The first protruding portion 14 may be a protrusion that does not extend linearly but protrudes in a dot shape.
The length L2 of the second protruding portion 15 is, for example, 50 to 80% of the folded width of the filter medium 11. Further, the tip portion 15a of the second protruding portion 15 is preferably located within a range of 90% or less, preferably 80% or less of the folding width of the filter medium 11 from the crease 10a. As described above, since the tip position of the tip portion 15a is separated from the crease 10b, the area of the filter medium 11 through which the air flow does not pass can be reduced. The filter pack 3 of the present embodiment has a V-shape having an edge in which only one crease is present at the top of the pleats (the valley-folded portion and the mountain-folded portion). Compared to a filter pack having a cross-sectional shape with two creases on the top, it is easier to increase the angle formed by the two extending portions 11a and 11b facing each other, and the effect of widening the pleated spacing described above is increased. Further, in the filter pack 3 having a V-shape in which only one crease is present at the top of the pleats, the tip portion 15a is arranged at a position away from the crease 15b, but the extending portions 11a and 11b. You can touch both of them.
The ratio L1 / L2 of L1 and L2 is preferably 0.1 to 0.5. As a result, the distance between the position where the second protruding portion 15 contacts the extending portion 11a and the position where the protruding portions 14 and 15 contact each other can be increased, and it is easy to stably maintain the V-shape of the filter medium 11. Become.

It is preferable that the projecting portions 14 and 15 are separated from each other with the creases 10a and 10b interposed therebetween. If the projecting portions 14 and 15 are integrated members, deformation (bulging) may occur in the vicinity of the folds of the pleats so that the two extending portions 11a and 11b facing each other are separated from each other, narrowing the flow path of the air flow. be. In particular, in a V-shaped filter pack having only one crease on the top of the pleats, such deformation is likely to occur. Further, when the projecting portions 14 and 15 are integrated members, when the protruding height is high, it is easy to generate a force that causes the two extending portions facing each other to separate from each other. On the other hand, when the protruding portions 14 and 15 are separated from each other, the deformation of the portion of the filter medium 11 near the folds of the pleats can be effectively suppressed. On the other hand, the protruding portions 14 and 15 may be integrally formed so as to straddle the creases 10a and 10b.

The frame body 5 is a member that surrounds the filter pack 3 so that the creases 10a and 10b of the filter medium 11 are arranged on the upstream side and the downstream side in the air flow direction. In the example shown in FIG. 1, the crease 10a of the filter medium 11 is arranged on the upstream side (direction opposite to the X direction). The frame body 5 is, for example, a rectangular member. The frame body 5 is made by combining, for example, a frame material such as a galvanized iron plate, a stainless steel plate, or a resin. In the air filter 1, the filter pack 3 is fixed to the frame body 5 at both ends in the Z direction using a sealing agent such as urethane resin, and the filter pack 3 is fixed in the Y direction using an adhesive extending linearly in the Z direction. By fixing both ends, it is assembled so as to eliminate the gap between the filter pack 3 and the frame body 5.

In the present embodiment, the position 15b where the projecting portions 14 and 15 abut is preferably located closer to the mountain-folded crease 10a than to the valley-folded crease 10b. Since the contact positions of the projecting portions 14 and 15 are located on the mountain side, the V-shaped shape can be stably maintained. Further, since the tip of the first protruding portion 14 is located on the mountain side, the area of the filter medium 11 through which the air flow does not pass is compared with the case where the tip of the first protruding portion 14 is located on the valley side. Can be reduced, and the effect of reducing pressure loss is increased. Further, since the V-shape is stably maintained, the widened pleated spacing can be stably maintained. The first protruding portion 14 is preferably located on the mountain side, and more preferably on the valley side, in terms of increasing the effect of widening the pleating interval. Further, the tip portion 15a of the second protruding portion 15 is preferably located on the valley side. The mountain side means the crease 10a side from the midpoint of the line segment connecting the creases 10a and 10b. The valley side means the crease 10b side from the midpoint.

The first protruding portion 14 is located within a length range of, for example, 10 to 40% of the folding width of the filter medium 11 from the crease 10a, preferably within a length range of less than 10 to 30%. It is more preferably located within a length range of less than 20-30%.
Further, the second protruding portion 15 is located within a range of, for example, 10 to 80% of the folding width of the filter medium 11 from the crease 10a, and preferably has a length of less than 10 to 70%. Located within range.

In the present embodiment, as described below, it is preferable that the dimensions and the like of the cross sections of the projecting portions 14 and 15 in the direction orthogonal to the extending direction are adjusted. Examples of such dimensions include the protrusion height, the width (the maximum length in the direction orthogonal to the height direction), the ratio of the protrusion height to the width, and the cross-sectional shape.

The protruding heights of the projecting portions 14 and 15 are, for example, 20 to 40% of the pleated spacing. The protruding heights of the projecting portions 14 and 15 may be equal to or different from each other.

The projecting portions 14 and 15 can be manufactured, for example, by placing a preformed resin on the filter medium 11 and adhering the resin, or by molding the resin on the filter medium 11 using a gun or the like.

The above-mentioned dimensions and the like regarding the cross sections of the projecting portions 14 and 15 may be constant or may change in the extending direction.

FIG. 3 is a diagram showing a cross section of a filter pack according to a modified example.
As shown in FIGS. 1 and 3, the space-holding material 13 may further have a connecting portion 16 in contact with the projecting portions 14 and 15 separated by sandwiching the crease 10a. The connecting portion 16 is formed so as to intersect the crease 10a along a direction (Y direction) orthogonal to the crease 10a. The connecting portion 16 suppresses the extension portions 11b and 11a on both sides of the crease 10a from being separated from each other, and suppresses the mountain-folded portion of the filter medium 11 from being deformed so as to swell, and suppresses the narrowing of the air flow path. It is effective. The connecting portion 16 of the illustrated example is further formed so as to be bridged between the folds 10a, and also exerts an effect of stably maintaining the pleated spacing.
The length (thickness) of the connecting portion 16 along the direction of the air flow is preferably smaller than the protruding height of the protruding portions 14 and 15.

Specifically, in the connecting portion 16 of the example shown in FIG. 3, the protruding portions 14 and 15 are formed on the surface of the filter medium 11, and then the filter medium 11 is folded, and the inside of the groove of the jig is as described above. The hot melt resin applied to the above is produced by turning the jig upside down, placing it on the crease 10a, and adhering it. In this way, the connecting portion 16 provided after the filter medium 11 is folded can effectively suppress the deformation such that the mountain-folded portion of the filter medium 11 swells.
On the other hand, as shown in the example shown in FIG. 2A, the spacing member 33 integrally formed so as to straddle the crease is, for example, hot melted by using a gun with the filter medium 31 spread out. Since it is formed by applying a resin, when the filter medium 31 is folded, the mountain-folded portion of the filter medium 31 is easily deformed so as to swell, which is one of the causes of increasing the pressure loss. Further, the valley fold portion of the filter medium tends to form a U-shape due to the tendency of swelling deformation, and it is difficult to widen the pleating interval.
In this embodiment, the connecting portion 16 may be manufactured by applying a hot melt resin using a gun, or molding and placing the resin in advance.

As shown in FIGS. 2A, 3 and 4, the spacing member 13 is on the side opposite to the first side (upstream side) surface of the filter medium 11 in which the projecting portions 14 and 15 are arranged. A third protrusion formed on the surface on the second side (downstream side) at the same position as the position where the crease 10a where the protrusions 14 and 15 are located extends in the extending direction (Z direction) and orthogonal to the crease 10b. It is preferable to further have a portion 18 and a fourth protruding portion 19. FIG. 4 is a diagram showing a cross section of a filter pack according to a modified example. As shown in FIG. 2A, the length L3 of the third protruding portion 18 in the extending direction may be shorter than the length L4 of the fourth protruding portion 19 in the extending direction. As shown in 4, it may be long.
In this case, the third protruding portion 18 is formed at a position where the first extending portion 11a is sandwiched between the tip portion 15a of the second protruding portion 15 and the fourth protruding portion 19 is formed. , It is preferable that the second extending portion 11b is formed at a position sandwiching the second extending portion 11b with the second protruding portion 15. As described above, when the third protruding portion 18 is arranged with respect to the tip portion 15a of the second protruding portion 15, the first extending portion 11a is on the downstream side when the air flow passes through. Supported by. Therefore, it is possible to prevent the valley fold portion from being deformed so as to bulge toward the downstream side and forming a U-shape.
Further, the tip portion 15a of the second protruding portion 15 is sandwiched and restrained between the third protruding portion 18 and the fourth protruding portion 19, so that the second protruding portion 15 is restrained. Since the tip portion 15a is stably located at the center position of the V-shape, the effect of facilitating the maintenance of the V-shape is increased, and the effect of facilitating the widening of the pleated spacing is increased.

As described above, when the spacing member 13 further has the projecting portions 18, 19, the length L3 of the third projecting portion 18 along the direction orthogonal to the creases 10a and 10b is the second. It is preferable that the length of the protruding portion 19 of 4 is shorter than the length L4.
FIG. 5 is a diagram showing a cross section of the filter pack 3 shown in FIG. 2 (b) in an unfolded manner. It is assumed that the projecting portions 14 and 18 having a short extending direction length are both arranged in the extending portion 11a, and the projecting portions 15 and 19 having a long extending direction length are arranged in the extending portion 11b. As shown in FIG. 5, the area where the protruding portions overlap on both sides of the filter medium 11 increases. Therefore, it is possible to suppress an increase in the area of the filter medium 11 through which the air flow does not pass. Even if the protruding portion is formed on only one side of the filter medium, the air flow cannot pass through it. Therefore, it is preferable that the protruding portion is positioned so as to overlap on both sides of the filter medium 11. The first protruding portion 14 and the third protruding portion 18 located on both sides of the first extending portion 11a are preferably separated from each other in a direction orthogonal to the creases 10a and 10b, for example. 10 to 30% of the folding width of the filter medium 11 is separated from each other.

(Examples, comparative examples)
A filter medium having a collection efficiency of 90% made of glass fiber was pleated by alternately performing mountain folds and valley folds every 120 mm using a rotary folding machine. For each mountain-folded crease of the filter medium, resin is molded in advance at multiple positions at multiple positions in the direction in which the crease extends, along the direction orthogonal to the crease, placed on the filter medium, and bonded. A protruding portion and a second protruding portion were provided. A third protruding portion and a fourth protruding portion were provided on the opposite surface of the filter medium in the same manner to prepare a filter pack as shown in FIG. 2 (b). The dimensions of the protruding part are as shown in Table 1 below. The dimensions of the cross section of the projecting portion were all constant in the extending direction.

Next, the folded filter medium was surrounded by an aluminum frame material, and the space between the folded filter medium and the filter medium was sealed with a sealing material and an adhesive to assemble the frame body, and an air filter was produced (Example).

On the other hand, a filter pack similar to that of the example was produced except that the space-retaining material having the form shown in FIG. 2 (a) was applied instead of the protruding portion by using a gun. The space-retaining material had a length of 72 mm, a width of 2.0 mm, a protruding height of 1.0 mm, and a semicircular cross-sectional shape from the mountain-folded crease to the end on the valley side. The lengths of the parts extending on both sides of the crease were equal. Next, the frame was assembled in the same manner as in the examples, and an air filter having the same outer dimensions as in the examples was produced (comparative example).
When the filter medium was folded, the magnitude of the force applied to the filter medium in the direction in which the pleated spacing was narrowed was the same in the examples and the comparative examples.

When the pressure loss when ventilated at an air volume of 56 m ³ / min using the produced air filter was measured using a differential pressure gauge, it was 104 Pa in the example and 122 Pa in the comparative example. From this result, the tip portion of the second protruding portion abuts on the first extending portion of the filter medium, and the tip portion of the second protruding portion abuts on the first extending portion at a position in the middle of the extending direction of the second protruding portion. It can be seen that the pressure loss can be reduced by providing the protruding portion.

Further, in the produced air filter, the number of pleats was 25 in Examples and 60 in Comparative Examples. The area of the filter medium was 1.788 m ² in the example and 4.290 m ² in the comparative example. From this result, the tip portion of the second protruding portion abuts on the first extending portion of the filter medium, and the tip portion of the second protruding portion abuts on the first extending portion at a position in the middle of the extending direction of the second protruding portion. As described above, it can be seen that the pleated spacing can be widened by providing the protruding portion, and as a result, the filter media area can be reduced.

Although the air filter and filter pack of the present invention have been described in detail above, the air filter and filter pack of the present invention are not limited to the above embodiments, and various improvements and changes are made without departing from the gist of the present invention. Of course, you may.

1 Air filter 3 Filter pack 5 Frame body 11 Filter material 13 Spacing material 14 First protruding part 15 Second protruding part 15a Tip of second protruding part 15b Position in the middle of the second protruding part 16 Connecting part 18 Third protruding part 19 Fourth protruding part

Claims (5)

A filter pack having a filter medium that collects fine particles in a gas and is pleated so that mountain folds and valley folds are alternately repeated, and an interval holding material that maintains the pleating interval of the filter medium.
A frame surrounding the filter pack is provided so that the folds of the filter medium are arranged on the upstream side and the downstream side in the air flow direction.
The filter medium is subjected to a force in a direction in which the pleated spacing is narrowed.
The spacing member is formed on the surface of the filter medium along a direction orthogonal to the crease, and is formed on a first extending portion of the filter medium extending to one side with the crease as a boundary. Has a protruding portion and a second protruding portion formed on the second extending portion of the filter medium extending to the other side.
The length of the first protruding portion along the direction orthogonal to the crease is shorter than the length of the second protruding portion.
In the valley-folded portion of the filter medium, the tip of the second protruding portion extending toward the valley-folded crease abuts on the first extending portion of the filter medium, and the second protruding portion is formed. The portion is in contact with the first protruding portion at a position in the middle of the extending direction of the second protruding portion.
The tip portion is located within a length of 80% or less of the distance between two adjacent folds across the second extending portion from the mountain-folded crease.
The first protruding portion is located on the side of the mountain-folded fold and is mountain-folded from the midpoint of the line segment connecting the two adjacent folds with the first extending portion in between. An air filter characterized by being located on the side of a valley-folded fold between the fold and the midpoint . The air filter according to claim 1, wherein the position where the second protruding portion and the first protruding portion abut is closer to the mountain-folded crease than the valley-folded crease. The space-holding material has the first protrusion on the second side surface opposite to the first side surface of the filter medium in which the first protrusion and the second protrusion are arranged. Further having a third protruding portion and a fourth protruding portion formed so as to be orthogonal to the crease at the same position as the position in the direction in which the crease extends where the protruding portion and the second protruding portion are located. death,
The third protruding portion is formed at a position where the first extending portion is sandwiched between the third protruding portion and the tip portion of the second protruding portion, and the fourth protruding portion is the second. The air filter according to claim 1 or 2, which is formed at a position where the second extending portion is sandwiched between the protruding portion and the protruding portion. The space-holding material has the first protrusion on the second side surface opposite to the first side surface of the filter medium in which the first protrusion and the second protrusion are arranged. Further having a third protruding portion and a fourth protruding portion formed so as to be orthogonal to the crease at the same position as the position in the direction in which the crease extends where the protruding portion and the second protruding portion are located. death,
The air filter according to any one of claims 1 to 3, wherein the length of the third protruding portion along the direction orthogonal to the crease is shorter than the length of the fourth protruding portion. A filter medium that collects fine particles in the gas and is pleated so that mountain folds and valley folds are repeated alternately.
It has an interval holding material that holds the pleated interval of the filter medium, and has.
The spacing member is formed on the surface of the filter medium along a direction orthogonal to the crease, and is formed on a first extending portion of the filter medium extending to one side with the crease as a boundary. Has a protruding portion and a second protruding portion formed on the second extending portion of the filter medium extending to the other side.
The length of the first protruding portion along the direction orthogonal to the crease is shorter than the length of the second protruding portion.
In the valley-folded portion of the filter media with the filter media folded, the tip of the second protruding portion extending toward the valley-folded crease abuts on the first extending portion. The second protruding portion is in contact with the first protruding portion at a position in the middle of the extending direction of the second protruding portion.
The tip portion is located within a length of 80% or less of the distance between two adjacent folds across the second extending portion from the mountain-folded crease.
The first protruding portion is located on the side of the mountain-folded fold and is mountain-folded from the midpoint of the line segment connecting the two adjacent folds with the first extending portion in between. A filter pack characterized by being located on the side of the valley fold between the fold and the midpoint .

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