JP4472398B2 - Air filter - Google Patents

Description

  The present invention relates to an air filter having heat resistance, which is used for circulating air cleaning such as a dryer and exhaust gas treatment for an incinerator, and can be used even in a high temperature range. Or it is related with the air filter used also for air cleaners, such as a semiconductor of a room temperature or a comparatively low temperature range, foodstuffs, and a hospital.

Conventionally, as this type of air filter, for example, as disclosed in Patent Document 1, a glass cotton cushion material layer is provided between a filter pack and a filter frame, and the front and rear end portions of the cushion material layer are further provided. In addition, a double seal layer made of an adhesive such as a silicone resin is known.
The adhesive layer is made of silicone resin because heat resistance is required. This silicone resin adhesive generates siloxane gas when the filter is used. The siloxane gas has a property of changing hydrophilicity to water repellency, and there is a possibility of adversely affecting substances on the downstream side of the filter by forming particles.
Therefore, as a structure not using an adhesive such as a silicone resin, as shown in FIG. 5, an ultrafine glass fiber is provided between a filter pack c and a filter frame g, each of which is a filter paper a and a separator b folded in a zigzag shape. It has been proposed to provide a sheet-like sealing material f and to insert cotton-like sealing materials d and e made of ultrafine glass fiber into the upper and lower ends of the filter paper a folded in a zigzag shape. In this structure, since the cotton-like sealing material made of ultra-fine glass fiber has a low density, the problem that the sealing property is likely to vary is improved by pressing and holding the sealing material between the filter frame g and the filter pack c. In addition, the sealing property can be secured without using an adhesive such as silicone resin at the front and rear ends.
However, there is a problem that the work of inserting the cotton-like sealing materials d and e made of ultrafine glass fibers is a manual operation, the workability is poor, the production efficiency of the air filter is lowered, and the cost of the air filter is increased.

Therefore, Patent Document 2 proposes to use an inorganic adhesive such as ceramic cement in place of the silicone resin of Patent Document 1 for the purpose of improving work efficiency without using a silicone resin. Has been.
However, the inorganic adhesive of Patent Document 2 has a problem that it is very expensive, and further improvement has been desired.
Japanese Utility Model Publication No. 61-51924 (Claim 1) Japanese Utility Model Publication No. 63-6023 (Claim 1)

  Therefore, the present invention provides an air filter that can be used in a high temperature range without using a silicone resin and a heat-resistant inorganic sealant, and that can improve the working efficiency for manufacturing the air filter. The purpose is to do.

The air filter of the present invention was made in order to solve the above-mentioned problem.As described in claim 1, a filter pack in which a corrugated separator is inserted in a folding space of a filter paper folded in a zigzag shape, The filter paper is accommodated in a filter frame via a sheet-shaped sealing material having a density of 20 to 120 kg / m ^{3 made} of ultrafine glass fibers having an average fiber diameter of 1 μm or less and arranged on the zigzag end portion side of the filter paper. The length of the filter paper is longer than the length of the separator in the direction between the end portions .
The air filter according to claim 2 is the air filter according to claim 1, wherein a rigid plate is inserted instead of at least one separator located in an intermediate region of the filter pack. The upper and lower end portions are brought into contact with the filter frame via the ultra-fine glass fiber sheet-shaped sealing material, and the ridgelines of the adjacent separators are arranged so as to cross each other via the filter paper. Features.
According to a third aspect of the present invention, in the air filter according to the second aspect, an ultra-fine glass fiber sealing material is embedded in a zigzag-shaped end portion of the filter paper folding space through which the rigid plate is inserted. It is characterized by doing so.
An air filter according to a fourth aspect of the present invention is the air filter according to any one of the first to third aspects, wherein the filter frame is separated from a U-shaped frame plate having ribs erected on the upstream and downstream sides. The tip of the rib is bent toward the inside of the air filter.

Thus, according to the air filter of the present invention, since no silicone resin sealant is used, there is no problem of generation of siloxane gas. Furthermore, it can be used without problems even in a high temperature range.
Further, since no inorganic adhesive is used, the time for applying the adhesive or the like is not required, and the manufacturing time of the air filter can be shortened. In addition, an inexpensive air filter can be provided without using an expensive inorganic adhesive.
Moreover, since the sealing material made of ultra-fine glass fibers is formed in a sheet shape, the sealing workability is excellent. Further, the density of the sheet is higher than the sealing material made of glass raw cotton, and a uniform sealing property can be secured over the entire surface of the sheet. Furthermore, the sheet-like sealing material made of ultrafine glass fibers can prevent the filter frame from expanding and contracting due to the ambient temperature and causing the filter pack to be deformed, so that a bypass leak between the filter pack and the filter frame can be prevented. It can prevent well.
Moreover, since the glass fiber which comprises a sheet | seat is ultra-fine, the specific surface area which touches a filter pack becomes large, and a sealing performance improves.
In addition, if the sheet-like sealing material made of ultra-fine glass fiber is brought into contact with the filter frame, the shock received by the air filter itself during transportation is absorbed, and the filter pack is protected from the shock. The state can be maintained. Furthermore, even if the separator is stretched in the vertical direction due to high heat during use, the elongation is absorbed, so that the filter pack can be similarly prevented from being damaged.
Furthermore, if a rigid plate is used instead of the separator located at the center of the filter frame and the ridgelines of adjacent separators are arranged to cross each other, the filter paper is crossed from both sides of the separator ridgelines. It is possible to stably hold and fix the portion, and the filter pack can be maintained in a good state for a long time. Furthermore, the sealing performance of the upper and lower end portions of the rigid plate can be improved by packing ultrafine glass fibers in the upper and lower end portions of the rigid plate.
Also, in the filter pack, by making the height of the filter paper higher than the height of the separator, the ultrafine glass fiber sealing material will bite into the upper and lower ends of the filter pack, and the ultrafine glass fiber sealing material and Integration with the filter pack can be achieved, and bypass leakage between the filter pack and the filter frame can be more effectively prevented.
Further, by bending the ribs of the filter frame inward, the sheet-like sealing material of ultra-fine glass fiber is difficult to see from the outside, and the appearance can be improved.

Next, the air filter of the present invention will be described with reference to the drawings.
FIG. 1: shows the front view (a) of the air filter of this invention, and its AA sectional drawing (b).
What is shown by 1 in the figure shows a filter frame, and the filter frame 1 is composed of four frame plates in which ribs 1a are erected on the upstream and downstream sides. In addition, the front-end | tip part of the rib 1a is bent toward the inner side of the filter. Reference numeral 2 denotes a filter pack accommodated in the filter frame 1 in an airtight manner. The filter pack 2 is composed of corrugated separators 2b, 2b,..., Which are formed by zigzag-folding inorganic fiber filter paper 2a in which inorganic fibers are bonded to each other with an organic binder, and are inserted into the filter paper folding space.
And in this invention, in order to seal between the filter pack 2 and the filter frame 1 of the outer periphery, the seal layer 4 is provided at least on the zigzag end portion side of the filter pack 2 and stored in the filter frame 1. Like to do. The sealing layer 4 is formed by forming ultrafine glass fibers having an average fiber diameter of 1 μm or less into a sheet shape having a density of 20 to 120 kg / m ³ .

As the inorganic fiber filter paper 2a, for example, a filter medium for HEPA or ULPA such as glass fiber paper by a papermaking method in which ultrafine glass fibers are bonded with an organic binder can be used.
Although it does not restrict | limit especially as the separator 2b, It is preferable to use aluminum and stainless steel metal foil.
As the sheet-like sealing material 4 made of ultra-fine glass fiber, one composed of inorganic fibers having a thickness of 1 to 4 mm, a weight per unit area of 80 to 120 g / m ² , and a density of 20 to 120 kg / m ³ can be used. In addition, it is possible to use an ultra-fine glass fiber having an average fiber diameter of 1 μm or less formed into a spun / collected sheet without using a binder. If the density of the sheet-like sealing material 4 made of ultra-fine glass fiber exceeds 120 kg / m ³ , the absorbability of the metal used for the filter frame 1, the separator 2 b, etc. becomes worse, and the unit of the filter pack 2 There is a problem that the load per area is increased and the filter pack 2 is deformed. If the density is less than 20 kg / m ³ , there is a problem that leakage occurs due to a small force for holding the filter pack 2. On the other hand, if the average fiber diameter exceeds 1 μm, the sealability becomes insufficient without being well adapted to the unevenness of the zigzag end of the filter pack 2.
The filter frame 1 is not particularly limited, but it is preferable to use aluminum, stainless steel, or a steel plate.

In the air filter, instead of at least one separator 2b positioned in the intermediate region B of the filter pack 2, a rigid plate 5 is inserted as shown in FIG. While making it contact | abut to the filter frame 1 through the sheet-like sealing material layer 4 of a very fine glass fiber, the ridgelines 11 and 12 of each adjacent separator 2b, 2b are inorganic, as FIG. 3 shows. It is preferable to arrange them so as to cross each other through the fiber filter paper 2a.
Furthermore, it is preferable to embed a superfine glass fiber sealing material 4 ′ in the zigzag end of the folding space of the filter paper 2 a inserted with the rigid plate 5.
Thereby, the filter pack can be maintained in a good and stable state over a long period of time. Accordingly, since the shape is stable even when used at a high temperature, there is no gap between the filter pack 2 and the sheet-like sealing material layer 4, so that the sealing performance can be improved. The superfine glass fiber sealing material 4 ′ may be in the form of a sheet, cotton, or felt, but is preferably a sheet from the viewpoint of workability.
As the rigid plate 5, a steel plate such as stainless steel or aluminum, a hard synthetic resin plate, wood, plywood or the like can be used. Among these, a stainless steel plate having heat resistance and corrosion resistance that can be used particularly at high temperatures is preferable.

Furthermore, as shown in FIG. 4, it is preferable that the height w1 of the filter of the filter paper 2a in the filter pack 2 is higher than the height w2 of the separator 2b.
Thereby, the sheet-like sealing material 4 bites into the upper and lower ends of the filter pack 2, and the sheet-like sealing material 4 and the filter pack 2 can be integrated, and the filter pack and the filter frame can be integrated with each other. This is because the sealing performance can be improved. Note that w2 is preferably shorter than w1 by several millimeters.

Next, specific examples of the present invention will be described under comparison with conventional examples and comparative examples.
In the air filter of Example 1, the sealing layer 4 in the air filter shown in the figure was configured as shown in Table 1 below. The air filters of Conventional Examples 1 to 3 and Comparative Examples 1 and 2 were configured as shown in Table 1 below instead of the seal layer 4 of the air filter of Example 1. Further, in any of Example 1, Conventional Examples 1 to 3 and Comparative Examples 1 and 2, the filter size after assembly is 610 mm × 610 mm × 290 mm, and the filter paper 2a and the separator 2b are made of the same material. The conditions were aligned.
The air filter of Example 1, the conventional examples 1 to 3 and the comparative examples 1 and 2 having the above-described configuration is manufactured, and the amount of sealing agent used in these air filters, the gas generating property, and the assembly workability of the air filter are evaluated. The results are shown in Table 2.
In addition, about the air filter of Example 1, the crossing separator was used as the separator 2b and the SUS304 stainless steel plate was used as the rigid board 5 as FIG. 2 shows.

As the evaluation of the amount of the adhesive used, the case where no adhesive was used was indicated by ◯, and the case where the adhesive was used was indicated by ×.
Moreover, as evaluation of gas generation amount, the thing which did not generate | occur | produce siloxane gas from one air filter was set as (circle), and the thing which generate | occur | produced was set as x.
As for the assembly workability of the air filter, the time required for assembling one air filter of Example 1 was set to 100, and 100 to 150 was evaluated as ◯ and over 150 was evaluated as X according to relative evaluation.
In addition, the sealing performance of the air filter is that which achieves 99.97% filtration efficiency (particle size 0.3 μm), and that which does not achieve 99.97% filtration efficiency (particle size 0.3 μm). X. In the heating test, the ambient temperature of each air filter is raised to 30 to 250 ° C. in 1 hour, maintained at 250 ° C. for 7 hours, and lowered to 250 to 30 ° C. in 4 hours (12 hours). Was repeated 20 cycles.
As a comprehensive evaluation, when all of the evaluation items are evaluations of ◯ or more, the evaluation is ○, and when any one evaluation item has an evaluation of ×, the evaluation is ×.

As shown in Table 2, since the air filter of Example 1 of the present invention uses the ultrafine glass fiber sheet-like sealing material, it was found that the air filter can be manufactured in a shorter time than the conventional example 3. .
In addition, the air filter of Example 1 had no problems such as generation of cracks or occurrence of bypass leaks because the filter medium could not follow the metal elongation of the filter frame or the separator even in the sealing performance of the air filter. It was found that excellent collection efficiency was obtained. In particular, it has been found that the separator ridge lines cross each other and that the sealing performance is excellent by using a rigid plate.
Moreover, it turned out that the air filter of Example 1 is superior to Conventional Examples 1 and 2 in terms of the amount of adhesive used in the air filter, and is superior to Conventional Example 1 in terms of gas generation.
Further, in Comparative Examples 1 and 2, since the glass fiber constituting the sheet-shaped sealing material has a larger average fiber diameter than the Examples, the adhesion with the filter frame and the filter pack is lowered, and the sealing performance of the air filter is reduced. It is thought that it was lowered.

  Next, regarding the air filter of Conventional Example 4 and the air filter of Example 2 used at room temperature shown in Table 3 below, the amount of sealant used, the assembling workability of the filter, and the sealing performance of the assembled air filter are as follows. The results are shown in Table 4. In addition, the structure of the air filter of Example 2 did not remove the rigid plate 5 from the air filter of Example 1 and crossed the arrangement of the separator 2b, but had a normal arrangement as in the conventional example.

For the evaluation of the amount of adhesive used, the case where no adhesive was used was marked with ◯, and the amount used was marked with x.
In addition, as to the assembling workability of the filter, the time required for manufacturing one air filter of Conventional Example 4 was set as 100, and 90 to 110 were evaluated as ◯ and less than 110 as × according to relative evaluation.
As the air filter sealing performance, the air filter collection efficiency is 99.97% (particle size 0.3 μm) or more at room temperature, and less than 99.97% (particle size 0.3 μm) is x. .

  As a comprehensive evaluation, when all of the evaluation items were ◯ or more, the evaluation was ○, and when any evaluation item had an evaluation of ×, it was evaluated as ×.

  As shown in Table 4, the air filter of Example 2 uses an ultrafine glass fiber sheet-like sealing material, but it was found that the filter can be manufactured in the same time as in Conventional Example 4. Moreover, since the air filter of Example 2 was excellent in adhesiveness with a filter pack, it turned out that sealing performance is excellent. Moreover, since the air filter of Example 2 does not use a sealing agent, it turned out that cost can be reduced compared with the prior art example 4. FIG.

  Explanatory drawing of the air filter of this invention (a: front view b: same AA sectional drawing)   Explanatory drawing which shows suitable embodiment of this invention   Explanatory drawing which shows other suitable embodiment of this invention.   Explanatory drawing which shows other suitable embodiment of this invention.   Explanatory drawing of a conventional air filter (a: front view b: same AA sectional view)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter frame 1a Rib 2 Filter pack 2a Filter paper 2b Separator 4 Sheet-like sealing material made of ultra-fine glass fiber 5 Rigid plate

Claims (4)

A filter pack in which corrugated separators are inserted in the zigzag folded space of the filter paper is arranged on the zigzag end side of the filter paper, and the density is 20 to 20 μm. The filter paper is housed in a filter frame through a 120 kg / m ³ sheet-shaped sealing material, and the length of the filter paper is longer than the length of the separator in the direction between the zigzag ends of the filter paper. Air filter.   Instead of at least one separator located in the middle region of the filter pack, a rigid plate is inserted, and the upper and lower ends of the rigid plate are brought into contact with the filter frame via the ultra-fine glass fiber sheet-like sealing material. 2. The air filter according to claim 1, wherein the air filters are arranged so that the ridgelines of the adjacent separators cross each other through the filter paper.   The air filter according to claim 2, wherein a sealing material of ultra-fine glass fiber is embedded in a zigzag end portion of the folding space of the filter paper with the rigid plate interposed therebetween. Claims the filter frame, constructed from the upstream and downstream sides a U-shaped frames which ribs erected on the front end portion of the rib, characterized in that bent inwardly of the air filter Item 4. The air filter according to any one of Items 1 to 3 .

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