JP4510690B2 - Gas adsorption filter - Google Patents

Description

  The present invention relates to a gas adsorption filter.

  Various types of gas adsorption filters, such as activated carbon filters, have been developed in the past, but it is usually said that the center part and the edge of the wall are most likely to break through. When the cross section is not a circle but a quadrangle, the corners have little contact with the adsorbent, and there is a concern that the performance will be significantly reduced.

  For this reason, some filters have a circular cross section with no corners for higher efficiency, and the wall flow problem tends to be considered as a square defect.

As a filter that suppresses local breakthrough from the wall flow, the present applicant has developed and proposed an absorption can for gas masks in which a non-breathable member is arranged on the entire circumference of the ventilation surface upstream of the adsorption layer (patent) Reference 1). Since this absorption can is for gas masks, it is mobile and has a circular cross section.
Japanese Patent Application No. 2004-54488

  As a fixed filter that is mounted on a local exhaust device such as an air purifier, a flat rectangular filter (including combinations thereof) is desirable in view of the effective installation area, ease of processing and fixing, and the like. .

An object of the present invention is to provide a flat quadrangular gas adsorption filter filled with a granular porous adsorbent, which does not increase the adsorbent capacity and does not substantially change the ventilation resistance. An object of the present invention is to provide a gas adsorption filter that suppresses wall flow, increases the contact efficiency between a gas that passes through the inside of the filter and an adsorbent, and has a high detoxification capability.

The present invention, first, in a filter having a flat quadrangular shape, both surfaces are made of a gas permeable member and filled with a granular porous adsorbent inside, is provided upstream and downstream of the adsorption layer. arrange flat non-permeable member in a square shape of the corners of one of the vent surfaces, gas adsorption, characterized in that arranged walls all around the non-air-permeable member over the other vent surface It is a filter for.

A second aspect of the present invention is the above filter, wherein the flat non-breathable member disposed at the corner of the square ventilation surface of the ventilation surface is made of a triangular plastic piece or metal piece .

  Thirdly, the present invention is the above-described filter installed in a pull hood of a push-pull type ventilation device.

  Fourthly, the present invention is the above filter, wherein the granular porous adsorbent is activated carbon.

The gas adsorption filter of the present invention can effectively suppress wall flow, has high contact efficiency between the gas passing through the filter and the adsorbent, does not increase the adsorbent capacity , and has a ventilation resistance. Since it exhibits a high detoxification effect with almost no change in the filter, it is an inexpensive and long-life filter that can be effectively used for cleaning contaminated air.

  The gas adsorption filter of the present invention is of a type having a flat and quadrangular shape, both sides of a breathable member including a nonwoven fabric and the like, and having an adsorption layer filled with a granular porous adsorbent such as granular activated carbon inside. Basically, any filter can be used as long as it is a fixed filter for cleaning air or other gases.

In the present invention, a non-ventilating member is arranged on the square of the vent surface which is an opening of these filters. The function of the non-breathable member is the same as the function of the non-breathable member in Patent Document 1, and it is sufficient that the air flow is substantially limited as compared with the vent surface on which the non-breathable member is not disposed. It does not need to be non-breathable. Usually, it means that the ventilation is limited to 50 to 100%, preferably 80 to 100%, compared to the ventilation surface where it is not arranged. Non-breathable members include metal pieces such as plastic pieces and aluminum tape. The shape of the non-breathable member arranged in the square is preferably triangular. Usually, it is preferable to place a right-angled triangular non-breathable member having a length of about 0.5 to 5%, particularly about 1 to 3% of each side in a square.

The arrangement of the non-breathable member in the square is preferably on the downstream side of the adsorption layer, but may be arranged on both sides or on the upstream side.
On the other side (for example, the upstream side) , a non-breathable member is disposed over the entire wall portion of the ventilation surface . The size is preferably such that it does not substantially affect the airflow resistance, usually 5 to 30% of the opening area, particularly about 10 to 25%.

  As an adsorbent to be filled, a conventionally known appropriate adsorbent can be used as long as it is a granular porous adsorbent having a gas adsorbing ability. As for the size and shape, those having an appropriate size and shape included in the granular concept such as powder, sphere, granule, and fragmented shape can be used. Particular preference is given to granular activated carbon. Other examples include porous inorganic adsorbents such as silica gel, molecular sieve, zeolite, activated alumina, activated clay.

Next, the present invention will be described with reference to the drawings.
FIG. 1 shows an example of the filter main body of the present invention. The upper diagram shows the ventilation upstream side, and the lower diagram shows the ventilation downstream side.

  Reference numeral 1 denotes a filter frame. The upper part of the cross-sectional view is the upstream side of the filter, and the lower part is the downstream side of the filter. The filter body 1 has a square shape or a rectangular shape. In the filter main body 1, a breathable member 3b formed by arranging a punching plate, a mesh, and a breathable sheet from the outside is attached to the bottom surface portion on the downstream side, and after inserting a granular porous adsorbent 4 such as activated carbon, the ventilation is performed. It has a structure in which a breathable member 3 a formed by disposing a conductive sheet, a mesh, and a punching plate is placed and filled while being pressed by the presser 5 and the lid 2. The air-permeable members 3a and 3b have the same configuration, and the punching plate is preferably made of metal that does not change the filter shape, and the opening ratio is preferably about 50%. A mesh is made of polyethylene or other plastics for the purpose of maintaining a space between the punching plate and the breathable sheet and improving the efficiency of the ventilation channel. A nonwoven fabric is usually used as the breathable sheet.

  The presser 5 is located between the lid 2 and the punching plate, and when the lid 2 is fixed to the filter body 1, the presser 5 pushes the punching plate so that an appropriate filling pressure can be stably obtained. ing. Moreover, since the presser 5 and the cover part 2 cover the wall part of a filter opening part, it has the effect which prevents a wall flow, and this plays the role of the air-impermeable member of an upstream.

  The non-breathable member 6 on the downstream side is disposed on the breathable member 3b. The non-breathable member 6 has a right triangle shape and is arranged on the square of the filter opening surface, but the mounting portion may be any part of the punching plate, mesh, or breathable sheet of the breathable member 3b.

The gas adsorption filter of the present invention can be used as an alternative to a conventionally used filter for an air purifier, but the effect is more prominent when installed in a pull hood of a push-pull type ventilation device.
As an example of installing a push-pull type ventilator, there is an example of installing for each anatomical table in a human anatomy training room.

  Currently, exposure to formaldehyde is a problem in human anatomy practice in the medical and dental education processes. Formaldehyde has an effect on human genes, and it has been pointed out that it is highly carcinogenic and allergic. Until now, various formaldehyde countermeasures have been taken in the fields of building material paints, cigarettes, and copying machines, but nothing is aimed at preventing the inhalation of formaldehyde gas in human anatomy practice in the medical and dental education processes.

  The present applicant has found that a push-pull type ventilator incorporating the filter of the present invention is particularly effective for cleaning the air containing formaldehyde gas.

Next, this invention is demonstrated based on an Example.
The conditions for measuring the ventilation resistance used in the examples are as follows.
Air flow rate 1.3m ³ / min
Measuring instrument Differential pressure type DP gauge

In the gas adsorption filter of the present invention, the resistance of the air-impermeable member 6 was changed as follows without changing the filter shape and configuration, and the ventilation resistance was measured and compared. Granular activated carbon was used as the adsorbent.
1. No non-venting member 2. Place a right triangle with a length of 1.5% on one side in a square. 3. Place a right triangle with 2% length on one side in a square. 4. Place a right triangle with a length of 2.5% on one side in a square. Arranged on the entire circumference with a width of 10 mm from the wall Table 1 shows the ventilation resistance and the rate of increase.

The conditions of the detoxification test used in the examples are as follows.
Test gas Formaldehyde Test gas concentration 30.00ppm
Breakthrough standard concentration 0.25ppm
Test flow rate 1.3m ³ / min

  In the gas adsorption filter of the present invention, a filter with the non-breathable member 6 and a filter without the air-permeable member 6 were manufactured without changing the filter shape and configuration, and a detoxification test was performed for comparison. The size of the non-venting member is No. 1 in Table 1. 2. The results are shown in Table 2.

Explanatory drawing which shows an example of the filter for gas adsorption | suction of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter main body 2 Lid part 3a Upstream side air permeable member 3b Downstream side air permeable member 4 Activated carbon 5 Presser | presser and upstream air permeable member 6 Downstream air permeable member

Claims (4)

In a filter having a flat quadrangular shape, both sides are made of a breathable member, and has an adsorption layer filled with a granular porous adsorbent inside, either the upstream or downstream side of the adsorption layer has a ventilation surface. Further, a triangular flat non-breathable member is arranged at the corner of the quadrangle, and the non-breathable member is not present on the other ventilation surface, and the other ventilation surface is provided over the entire circumference of the wall portion. A gas adsorption filter comprising a non-breathable member. 2. The filter according to claim 1, wherein the triangular flat non-breathable member disposed at the corner of the square ventilation surface of the ventilation surface is made of a plastic piece or a metal piece.   The filter according to claim 1 or 2, wherein the filter is installed in a pull hood of a push-pull type ventilation device.   The filter according to any one of claims 1 to 3, wherein the granular porous adsorbent is activated carbon.

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