JP2007050342A - Filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter with reduced structural pressure loss caused by air resistance when using the filter. <P>SOLUTION: This filter includes a filter medium formed in a crest and valley type. The crest part of the filter medium on the upstream side of the filter has two slopes and a ridge part, and in the inside of the crest part in a section orthogonal to the longitudinal direction of the ridge part, a circle inscribed with the two slopes and ridge part has a diameter R1 of 0.5-20% of the crest height H, and 50% or less of a space W of adjacent valleys. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a filter used for air purification and liquid purification, and more particularly to a filter using a filter medium obtained by folding a sheet-like material such as a nonwoven fabric or filter paper.

  Filters using filter media formed in a mountain-and-valley shape are widely used for air conditioning in buildings, and household equipment such as air purifiers, vacuum cleaners, and air conditioners.

  The purpose of forming the filter medium in a valley shape is to increase the effective filtration area of the filter medium within a predetermined filter size, but the filter medium contacts between adjacent mountains and valleys, and fluids such as air stagnate. In order to prevent this, for example, as a filter with a retainer, as shown in Patent Document 1 and Patent Document 2, a retainer is formed by applying an adhesive continuously or intermittently to the surface of a filter medium and curing it. However, there is a method for securing a space between mountains and valleys.

  Moreover, as shown in Patent Document 3, Patent Document 4 and Patent Document 5, as a filter with a position control member for a mountain valley, the position of the mountain valley is regulated by a member formed of metal, nonwoven fabric, etc. There is also a method of securing the space, but all of these methods are only focused on securing the interval between the valleys, and in the filter medium disclosed there, when used as a filter, as shown in FIG. In addition, the filter medium is deformed by the resistance of air, and a portion 17 where air does not flow is generated at the upstream peak portion, which causes a structural pressure loss.

  In addition, in any of the above-described techniques, it is necessary to arrange a certain substance having an appropriate strength on the surface of the filter medium as a retainer or a position regulating member. There were also inconveniences such as an increase in the weight of the.

As a cause of the structural pressure loss in the filter medium, the present inventors have found that the filter medium is deformed due to the resistance of air and a portion where air does not flow is generated at the upstream peak, and this phenomenon occurs. As a result of intensive studies to improve the above, the present invention has been achieved.
JP-A-2-284626 Japanese Patent No. 3003685 JP 62-225222 A Japanese Patent Laid-Open No. 5-184841 Japanese Utility Model Publication No. 63-46913

  An object of the present invention is to provide a filter that solves the problems in the conventional filter described above and reduces the structural pressure loss caused by air resistance when the filter is used.

    In order to achieve the above object, the filter of the present invention has the following configuration. That is, a filter including a filter medium formed in a mountain-valley shape, wherein the peak portion of the filter medium located on the upstream side of the filter has two slope portions and a ridge portion, and a cross section perpendicular to the longitudinal direction of the ridge portion. When a circle inscribed in the two slope portions and the ridge portion is drawn on the inner side of the top of the mountain, the diameter (R1) of the circle is not less than 0.5% and not more than 20% of the peak height (H). , 50% or less of the interval (W) between adjacent valleys.

  Here, it is preferable that a groove is formed between each of the two slope portions and the ridge portion, and the valley top portion of the filter medium located on the downstream side of the filter has two slope portions and a valley bottom portion. When a circle inscribed in the two slope portions and the valley bottom portion is drawn inside the valley top portion in the cross section perpendicular to the longitudinal direction of the ridge portion, the diameter (R2) of the circle is the height of the mountain height (H). It is also preferable that it is 0.5% or less, and it is also preferable that the space | interval (W) of an adjacent trough exists in the range of 5-30% of the said peak height (H).

Further, the sheet-like material constituting the filter medium used in the present invention has a bending resistance of 250 mg or more in the measurement based on JIS-L-1079: Gurley method, and 0.07 g / cm ³ or more and 0.2 g. It is also preferred to have an apparent density of less than / cm ³ . Furthermore, it is also preferable that the filter medium formed in the shape of a valley does not have a support for maintaining the interval between the peaks and valleys.

  The filter described above includes a frame body around the filter, and the filter body is configured by integrating the frame body and the filter.

  ADVANTAGE OF THE INVENTION According to this invention, it can be set as the filter and filter unit which can reduce the pressure loss which arises by the air resistance at the time of filter use. In addition, according to the present invention, the above-described effects can be effectively exhibited without increasing the filter weight.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  The filter of the present invention includes a filter medium formed in a mountain-valley shape, and the peak portion has two slopes and a ridge portion. FIG. 1 is a schematic cross-sectional view of a filter medium according to an embodiment of the present invention in a cross section perpendicular to the longitudinal direction of the ridge. FIG. 2 is an enlarged schematic cross-sectional view showing a peak portion located on the upstream side of the filter in FIG. A fluid such as air is supplied in the direction of the arrow A in the figure and filtered. FIG. 4 is a schematic cross-sectional view in a state where a fluid is supplied in the direction of arrow A to the filter medium shown in FIG. FIG. 3 is a schematic perspective view showing an example of a filter unit in which the frame 18 is arranged around the filter and the frame and the filter are integrated. In this example, the filter includes a filter medium 1 formed in a mountain-and-valley shape and another filter medium 19 made of a nonwoven fabric or the like.

  In FIGS. 1 and 2, when the peak portion of the filter medium 1 formed in the shape of a valley is drawn inside the circle 5 inscribed in the one side slope, the ridge, and the other one side slope, It has a space where the diameter (R1) is 0.5% or more and 20% or less of the peak height (H) and 50% or less of the interval (W) between adjacent valleys.

  Since the filter medium in the present invention has a space on the inner side of the upstream peak, even if the air flowing in the direction of the arrow A is deformed in the filter medium due to the resistance of the air when the filter is used, FIG. As shown in FIG. 5, a space through which air flows is secured in the filter medium 1, and the air is filtered with little pressure loss.

  Here, when the diameter (R1) of the above-mentioned circle is 50% or less of the interval (W) between adjacent valleys, but less than 0.5% with respect to the peak height (H), A sufficient space cannot be secured inside, and when the filter medium is deformed by the resistance of air, the one-side slope and the other one-side slope come into contact with each other. The part 17 which does not distribute | circulate arises, and it becomes easy to produce a structural pressure loss.

  Moreover, even if the diameter (R1) of the above-mentioned circle is 50% or less of the interval (W) between the adjacent valleys, the ridge portion becomes larger when it exceeds 20% with respect to the mountain height (H). The air resistance per unit area received at this portion increases, and the pressure loss tends to increase.

  In addition, even when the diameter (R1) of the circle is 0.5% or more and 20% or less with respect to the peak height (H), if it exceeds 50% of the valley interval (W), a predetermined filter dimension is used. There is a tendency that the resistance to air of the entire filter increases and the filtration efficiency decreases due to the relationship with the interval (W) between adjacent valleys suitable for increasing the effective filtration area of the filter medium.

  Here, the interval (W) between adjacent valleys refers to the distance between adjacent valleys. The relationship between the mountain height (H) and the distance between adjacent valleys will be described in detail later. For example, in the case of a mountain valley shape with a mountain height (H) of 30 mm, the most suitable interval (W) between adjacent valleys is Although it is about 3.5 mm, if the circle diameter (R1) exceeds 50% of the valley spacing, it will exceed 1.75 mm, and the distance between adjacent mountains will be shortened, making it difficult for air to pass. The flow of air in the valleys becomes worse, and the pressure loss tends to increase.

  In addition, the space as described above may be provided on both the upstream mountain peak and the downstream valley peak, but if the relationship between the peak height and the distance between adjacent valleys is suitably set, the filter Even when the filter medium is deformed by the resistance of air during use, the air flow passage at the downstream valley top is not blocked, so it does not have to be inside the downstream valley, and a predetermined filter Selection can be made while considering increasing the effective filtration area of the filter medium within the dimensions. From such a viewpoint, the top of the valley of the filter medium located on the downstream side of the filter has substantially no valley bottom, or two slopes inside the valley top in the cross section orthogonal to the longitudinal direction of the ridge. When a circle inscribed in the part and the valley bottom is drawn, the diameter (R2) of the circle is preferably 0.5% or less of the peak height (H).

  Here, the method for forming the space at the upstream peak portion or the downstream valley peak portion of the filter medium is not particularly limited, but it is formed by bending the sheet-like material 1a constituting the filter medium with a groove. Is preferred. In this method of forming a space by grooving, in order to accurately process the size of the space inside the upstream mountain peak or downstream valley peak, and accurately process the interval between the peaks and valleys, FIG. It is efficient to use an apparatus as shown in FIG. Here, a method for producing a mountain-shaped filter medium having a space at the top of a mountain or valley will be described in detail using the apparatus shown in FIG.

  The sheet-like material 1a, which is the raw material of the filter medium, is set on the feed roll 10, and the recoil of the sheet-like material 1a passes between both rolls in contact with the transport rollers 6a and 6b, and the groove of the grooving section It passes between the both rolls in a state of passing between the attachment plates 9a and 9b and the receiving grooves 8a and 8b and in contact with the conveying rollers 7a and 7b.

  The sheet-like material 1a passed between the transport rollers 6a and 6b and the transport rollers 7a and 7b is sequentially transported in the direction of the arrow B as the respective transport rollers 6a and 6b and 7a and 7b rotate. At this time, the conveyance amount of the sheet-like material 1a can be controlled by arbitrarily rotating or stopping each of the conveyance rollers 6a, 6b, 7a, and 7b, thereby performing grooving processing on the sheet-like material 1a. Determine the location.

  FIG. 6 is a schematic cross-sectional view showing an example of the pair of grooved plates 9 and the receiving grooves 8 in the grooved portion 11. Moreover, FIG. 7, FIG. 8 and FIG. 9 are schematic sectional views showing other similar examples.

  In the grooving portion 11 in FIG. 5, the grooved plate 9a or 9b is lowered, so that the sheet 1a is sandwiched between the grooved plate 9 and the receiving groove 8 as shown in FIGS. 12, the surface of the sheet-like material 1a is grooved.

  Here, in order to obtain a desired diameter (R) of the circle, as shown in FIGS. 6 and 8, the groove plate thickness 13 and the receiving groove angle 14 are appropriately set or installed. The attachment plate can be shaped as shown in FIGS.

  With such an apparatus, the distance between adjacent peaks and valleys can be controlled by appropriately controlling the position where the sheet-like material 1a is grooved.

  As a folding method for forming the grooved sheet-like material into a mountain-valley shape, for example, a method using a reciprocating type or rotary type folding machine can be used.

  As a method of forming a space at the upstream peak or downstream valley peak of the filter medium, in addition to the method of forming a space by bending the sheet-like material as shown above, as shown in FIG. It is also possible to use a rod-like support 15 made of metal, glass, plastic, etc., and attach this support 15 to a frame member to form a space. In this case, the amount of deformation of the filter medium due to air resistance can be further reduced by supporting the peak portion of the filter medium formed in a mountain-valley shape. In addition to this, a molding method such as a method of pressing with pressing dies 16a and 16b formed in a mountain-and-valley shape as shown in FIG. 11 can be used.

  In the present invention, the interval (W) between the adjacent valleys and the height (H) of the peaks are arbitrary and are not particularly limited, but the interval (W) between the adjacent valleys is It may be 5 to 30% of the height (H), preferably 10 to 20%. Here, the interval between adjacent valleys refers to the distance between adjacent valleys. If the interval between the valleys described above is too small compared to the height of the peaks, the resistance to air will increase and the filtration efficiency will tend to decrease. Conversely, if it is too large, the filter media will fall within the specified filter dimensions. It becomes difficult to provide an effective filtration area.

  Moreover, the filter effective area of the filter medium within a filter dimension can also be increased by making the filter medium formed in the shape of a mountain valley into a filter arranged in a W shape.

  In the present invention, the type of the sheet-like material constituting the filter medium is not particularly limited, and examples thereof include a short fiber nonwoven fabric and a long fiber nonwoven fabric. Examples of the fibers constituting the nonwoven fabric include organic fibers such as glass fibers, polyethylene fibers, polypropylene fibers and polyester fibers, natural fibers such as pulp and hemp, activated carbon fibers obtained by carbonizing and activating cellulose, acrylic or lignin fibers, Inorganic fibers such as metal fibers and glass fibers can be used. In addition, as a sheet-like material, an electret-treated polypropylene fiber nonwoven fabric, a polytotetrafluoroethylene porous film in which a breathable support made of an organic fiber nonwoven fabric such as polyethylene or polyester is laminated on at least one surface, a radiation graft polymerization reaction It is also possible to use ion-exchange nonwoven fabrics manufactured using

In particular, non-woven fabrics made of glass fibers and polypropylene fibers treated with electrets are preferably used in the present invention, which are preferably used as filter media for air conditioners in buildings and filters for household appliances such as air cleaners, vacuum cleaners and air conditioners. .
In addition, if the bending resistance of the sheet-like material is 250 mg or more in the measurement based on JIS-L-1079: Gurley method, the above-described pleated shape is maintained and structural pressure loss is generated as much as possible. This is preferable because it can be suppressed. Furthermore, when the apparent density of the sheet-like material is 0.07 g / cm ³ or more and less than 0.2 g / cm ³ , the above-described mountain-valley shape is maintained, and the occurrence of structural pressure loss is suppressed as much as possible. This can be achieved more and more, and since there is an appropriate space inside the sheet, such a sheet-like object is likely to form a mountain-valley shape.

The apparent density of the sheet-like material can be obtained by dividing the weight (W) of the sheet-like material by the volume (V) of the sheet-like material as shown in the following formula, and the thickness of the sheet-like material is 3 cm square. It can be obtained by applying a load of 0.25 g / cm ² to the sample and applying a load to the sheet and measuring it with a dial gauge.

ρ = W / V
ρ: Apparent density (g / cm ³ )
W: Weight of sheet-like material (g / m ² )
V: Volume of sheet-like material (cm ³ )
V = T × 10000
T: Sheet thickness (mm)
In the present invention, it is not necessary to lay a retainer or a valley / valve position regulating member, but unless it deviates from the purpose of the present invention, the filter medium produced by the bending resistance and the apparent density of the sheet-like material and the air resistance when the filter is used. It does not preclude the use of an appropriate retainer or peak / valley position restricting member in accordance with the degree of deformation.

  The filter of the present invention may be composed only of the above-described filter medium, but as shown in FIG. 3, the filter may be configured in combination with another filter medium 19 made of a nonwoven fabric or the like. Each of the filter medium 1 and the separate filter medium 19 formed in a mountain-like shape may be configured as a single layer, or may be a filter having a multilayer structure in which a plurality of filter media are stacked. These filter media may be the same type or different types. For example, when different types of filter media are stacked, a coarse filter medium can be arranged on the inflow side of a fluid such as air, and a fine filter medium can be arranged on the outflow side. Further, if the filter medium is, for example, a filter in which an antibacterial filter medium and a deodorant filter medium are stacked, a plurality of functions can be imparted.

  In addition, the filter media 1 and other filter media 19 formed in a mountain-and-valley shape are individually or combined with properties such as antibacterial properties, antiviral properties, fungicidal properties, aromatic properties, deodorizing properties, and antiallergenic properties. It may be given. When antibacterial properties are imparted to, for example, a filter medium formed in a mountain-and-valley shape, various fungi can be prevented from growing on the filter medium, and the life of the filter medium can be extended. When applied to another filter medium, the other filter medium is arranged on the upstream side to prevent the air containing fungi from being supplied to the downstream filter medium, or the other filter medium is arranged on the downstream side. It is possible to prevent fungi from mixing into the filtered air. In addition, even when deodorizing property or fragrance is imparted, clean air can be supplied, and the usable time can be extended. As a means for imparting the above-mentioned functions, a method of applying a drug having such a function to a filter medium, a method of kneading such a drug in advance in the filter medium, or a filter medium manufactured with a material having the above-described function And how to do it. These functions can be given by appropriately selecting the above-described means.

  As shown in FIG. 3, the filter as described above is usually configured as a filter unit by arranging a frame 18 around it and integrating the frame 18 and the filter. The integration increases the strength of the filter and makes it easy to handle. Also, the above-described functions such as antibacterial properties can be imparted to the frame body alone or in combination.

Example 1
FIG. 5 shows a non-woven fabric having a basis weight of 100 g / m ² (a laminate of an electret polypropylene meltblown non-woven fabric and a short fiber non-woven fabric, JIS-L-1079: flexural softness 320 mg based on Gurley method, apparent density 0.16 g / cm ³ ). Using the grooving machine with the structure shown, grooving with a height (H) of 58 mm, a width of 591 mm, and an interval between two parallel grooves to form a space inside the upstream peak. After that, it was folded into a mountain-valley shape to obtain a HEPA filter (filter medium use area 10 m ² , size 610 mm × 610 mm × 65 mm, rated air flow 56 m ³ / min). The peak part and valley part of the obtained filter medium each have two slope parts and a ridge part, the diameter (R1) of the circle inside the upstream peak part is 0.5 mm, and the downstream valley peak inside The diameter (R2) of the circle was 0.1 mm, and the interval (W) between adjacent valleys was 5 mm.

This filter was measured for pressure loss and collection efficiency (counting method using 0.3 micron DOP particles) in a wind pressure test (JIS B-9908) up to a final pressure loss value of 294 Pa (30 mmAq). The results are summarized in Table 1.
(Example 2)
FIG. 5 shows a nonwoven fabric having a basis weight of 100 g / m ² (a laminate of an electret polypropylene meltblown nonwoven fabric and a short fiber nonwoven fabric, JIS-L-1079: bending resistance of 240 mg based on the Gurley method, apparent density 0.06 g / cm ³ ). Using a grooving machine having the structure shown, grooving with a height (H) of 58 mm, a width of 591 mm, and an interval between two parallel grooves to form a space inside the upstream peak, 1.0 mm After that, it was folded into a mountain-valley shape to obtain a HEPA filter (filter medium use area 10 m ² , size 610 mm × 610 mm × 65 mm, rated air flow 56 m ³ / min). The peak and valley of the obtained filter medium each have two slopes and a ridge, and the diameter (R1) of the circle inside the upstream peak is 1.0 mm, and the downstream valley peak is inside. The diameter (R2) of the circle was 0.1 mm, and the interval between adjacent valleys was 5 mm (W).

This filter was measured for pressure loss and collection efficiency (counting method using 0.3 micron DOP particles) in a wind pressure test (JIS B-9908) up to a final pressure loss value of 294 Pa (30 mmAq). The results are summarized in Table 1.
(Comparative Example 1)
FIG. 5 shows a non-woven fabric having a basis weight of 100 g / m ² (a laminate of an electret polypropylene meltblown non-woven fabric and a short fiber non-woven fabric, JIS-L-1079: a bending resistance of 320 mg based on the Gurley method, an apparent density of 0.16 g / cm ³ ). Using the grooving machine having the structure shown, grooving with a height (H) of a mountain of 58 mm, a width of 591 mm, and an interval between two parallel grooves for forming a space inside the peak of the upstream side is 0.2 mm. After that, it was folded into a mountain-valley shape to obtain a HEPA filter (filter medium use area 10 m ² , size 610 mm × 610 mm × 65 mm, rated air flow 56 m ³ / min). The peak and valley of the obtained filter medium each have two slopes and a ridge, and the diameter (R1) of the circle inside the upstream peak is 0.2 mm, and the downstream valley peak is inside. The diameter (R2) of the circle was 0.1 mm, and the interval (W) between adjacent valleys was 5 mm.

  This filter was measured for pressure loss and collection efficiency (counting method using 0.3 micron DOP particles) in a wind pressure test (JIS B-9908) up to a final pressure loss value of 294 Pa (30 mmAq). The results are summarized in Table 1.

The diameter of the circle is 0.2 mm, and it is not possible to secure a sufficient space for the air to flow inside the upstream peak formed in the shape of a valley, and the filter medium is deformed by the resistance of the air when the filter is used. In addition, since a portion where air does not flow is generated at the upstream peak, both the pressure loss and the collection efficiency are deteriorated as compared with Example 1 and Example 2, and sufficient performance as a HEPA filter cannot be obtained.
(Comparative Example 2)
FIG. 5 shows a nonwoven fabric having a basis weight of 100 g / m ² (a laminate of an electret polypropylene meltblown nonwoven fabric and a short fiber nonwoven fabric, JIS-L-1079: flexural flexibility of 320 mg based on the Gurley method. Apparent density of 0.16 g / cm ³ ). Using the grooving machine having the structure shown, grooving with a height (H) of 58 mm, a width of 591 mm, and an interval of 2.6 mm between two parallel grooves to form a space inside the upstream peak. After that, it was folded into a mountain-valley shape to obtain a HEPA filter (filter medium use area 10 m ² , size 610 mm × 610 mm × 65 mm, rated air flow 56 m ³ / min). The peak part and valley part of the obtained filter medium each have two slope parts and a ridge part, the diameter (R1) of the circle inside the upstream peak part is 2.5 mm, and the downstream valley top part is inside. The diameter (R2) of the circle was 0.1 mm, and the interval (W) between adjacent valleys was 5 mm.

  This filter was measured for pressure loss and collection efficiency (counting method using 0.3 micron DOP particles) in a wind pressure test (JIS B-9908) up to a final pressure loss value of 294 Pa (30 mmAq). The results are summarized in Table 1.

  Although the circle has a diameter of 2.5 mm and there is sufficient space for air to flow on the upstream peak of the pleat-shaped peak, there is not enough distance between adjacent peaks, so the pleat valley As a result, the pressure flow and the collection efficiency were deteriorated as compared with Example 1 and Example 2, and sufficient performance as a HEPA filter was not obtained.

  The present invention can be applied not only to filters for air purifiers but also to filters for liquid filtration.

It is a schematic sectional drawing of a filter. It is a general | schematic cross-sectional enlarged view of the mountaintop part of an upstream. It is a partially transparent schematic perspective view of a filter unit. It is a schematic sectional drawing of a filter when air is flowed. It is the schematic of a grooving processing apparatus. It is an enlarged view of a grooving process part. It is an enlarged view of a grooving process part. It is an enlarged view of a grooving process part. It is an enlarged view of a grooving process part. It is the schematic of the filter using a support body. It is the schematic of a press work apparatus. It is a schematic sectional drawing of a filter when air is flowed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter medium 1a Sheet-like object 2, 4 Contact in one side slope 3 Contact in ridge part 5 Circle 6a, 6b, 7a, 7b inscribed in two slope parts and ridge part Conveyance roller 8, 8a, 8b Receptacle 9, 9a, 9b Grooving plate 10 Feeding roll 11 Grooving processing portion 12 Contact portion 13 Plate thickness 14 Receiving groove angle 15 Supports 16a, 16b Stamping die formed in a mountain valley shape
17 A portion where air does not flow 18 Frame 19 Another filter medium

Claims (7)

  A filter including a filter medium formed in a mountain-valley shape, wherein the peak of the filter medium located on the upstream side of the filter has two slopes and a ridge, and the peak in a cross section perpendicular to the longitudinal direction of the ridge When a circle inscribed in the two slope parts and the ridge part is drawn inside the part, the diameter (R1) of the circle is not less than 0.5% and not more than 20% of the peak height (H), and adjacent to each other. A filter, which is 50% or less of the interval (W) between the valleys.   The filter according to claim 1, wherein a groove is formed between each of the two slope portions and the ridge portion.   The top of the filter media located on the downstream side of the filter has two slope portions and a valley bottom portion, and is inside the two slope portions and the valley bottom portion inside the valley top portion in a cross section perpendicular to the longitudinal direction of the ridge portion. The filter according to claim 1 or 2, wherein, when a circle that touches is drawn, a diameter (R2) of the circle is 0.5% or less of a peak height (H).   The filter according to any one of claims 1 to 3, wherein an interval (W) between adjacent valleys is in a range of 5 to 30% of the peak height (H). The sheet-like material constituting the filter medium has a bending resistance of 250 mg or more and an apparent density of 0.07 g / cm ³ or more and less than 0.2 g / cm ^{3 in the} measurement based on JIS-L-1079: Gurley method. It has a filter in any one of Claims 1-4.   The filter according to any one of claims 1 to 5, wherein the filter medium formed in a mountain-and-valley shape does not have a support for maintaining an interval between the peaks and valleys.   A filter unit in which a frame is arranged around the filter according to claim 1, and the frame and the filter are integrated.

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