KR102343662B1 - Multilayer filter - Google Patents

Abstract

An embodiment according to the present invention, as a porous substrate including a plurality of pores, a plurality of porous layers arranged in one direction; and a perforated layer disposed between at least two adjacent porous layers and having a perforation penetrating between one surface and the other surface.

Description

Multilayer filter {MULTILAYER FILTER}

The present invention relates to a multilayer filter, and more particularly, to a multilayer filter for filtering and removing particulate matter contained in a flowing gas such as air.

Recently, as the harmfulness of fine dust to the human body is widely known, interest in indoor air quality as well as outdoor air is rapidly increasing.

Most air purifiers for indoor air purification use particle filters and activated carbon together to reduce dust, harmful gases, or volatile organic compounds (VOCs).

In general, particle filters can be classified into a medium filter that filters particles of PM 2.5 level and a high efficiency particulate air filter (HEPA filter) that filters particles of PM 1 or less.

HEPA filters are mainly manufactured by extracting high-molecular components such as polyurethane and polypropylene or borosilicate glass into thin fibers and laminating them at high density. For this reason, since the HEPA filter has a very high back pressure (pressure difference between the front end and the rear end of the filter), it is difficult to secure an appropriate air volume.

In the air purification industry, there is no effective solution other than a method of increasing the area of the filter in order to lower the back pressure of the filter.

The four representative mechanisms that an air purifying filter filters particles are: Inertial Impaction of particles on the filter member, Interception when particles flowing along the stream come into contact with the filter member, and streamline due to concentration diffusion. There are two types of particles, which are separated from the filter member, by contact with the filter member and are collected (Diffusion) and collected by electrostatic attraction between the particles and the filter member (Electrostatic attraction).

In case of very small particles, they are filtered by diffusion, large particles are filtered by interception, and particles with large inertia compared to drag force can be filtered by inertial impaction. However, in the case of particles of a certain size, the efficiency of the three mechanisms of diffusion, interception, and inertial impaction is lowered, so that the overall filtration efficiency is greatly reduced. For example, particles of 0.3 μm level may correspond to this.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multilayer filter capable of improving filtration efficiency while reducing back pressure by increasing the increase/decrease in flow rate.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

An embodiment according to the present invention, as a porous substrate including a plurality of pores, a plurality of porous layers arranged in one direction; and a perforated layer disposed between at least two adjacent porous layers and having a perforation penetrating between one surface and the other surface.

In this embodiment, the number of pores included per unit inch (1 inch) in the porous layer is preferably 10 ppi to 200 ppi (pore per inch).

In this embodiment, it is preferable that the number of pores included per unit inch in each of the plurality of porous layers increases or decreases according to the order in which they are arranged along the one direction.

In this embodiment, it is preferable that the flowing gas moves along the one direction, and the number of pores included in each of the plurality of porous layers per unit inch increases along the one direction.

In this embodiment, it is preferable that a plurality of the perforated layers are provided and arranged along the one direction.

In this embodiment, it is preferable that at least some of the perforations formed in the perforated layer are randomly arranged so that the phases between the perforated layers adjacent to each other do not coincide.

In this embodiment, the porous layer may be a porous substrate including a plurality of pores.

In this embodiment, it is preferable that the number of pores included per unit inch in each of the plurality of perforated layers of the porous substrate increases or decreases according to the order in which they are arranged along the one direction.

In this embodiment, the plurality of porous layers and the porous layer may have a plate shape.

In this embodiment, the plurality of porous layers and the porous layer may have a cylindrical shape.

According to the multilayer filter according to the embodiment of the present invention, there is an advantage that the back pressure can be greatly reduced compared to the filter of the prior art, while the filtration efficiency can be maintained high.

Effects of the present invention are not limited to the above-described effects, and effects not mentioned will be clearly understood by those skilled in the art from the present specification and accompanying drawings.

1 is a schematic perspective view of a multilayer filter according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the multilayer filter shown in FIG. 1 .
3 is an exploded perspective view of a multilayer filter according to another exemplary embodiment of the present invention.
4 is a schematic perspective view of a multilayer filter according to another embodiment of the present invention.
FIG. 5 is an exploded perspective view of the multilayer filter shown in FIG. 4 .

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. On the other hand, the terms used herein are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and/or "comprising" refers to the presence of one or more other components, steps, operations and/or elements mentioned. or addition is not excluded. Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1 is a schematic perspective view of a multilayer filter according to an exemplary embodiment of the present invention, FIG. 2 is an exploded perspective view of the multilayer filter shown in FIG. 1 , and FIG. 3 is an exploded perspective view of the multilayer filter according to another exemplary embodiment of the present invention to be.

The multilayer filter 1000 according to an embodiment of the present invention relates to a layered structure for filtering and removing particulate matter included in a flowing gas such as air, and includes porous layers 100a and 100b and porous layers 200a and 200b. , 200c) may be included.

The porous layers 100a and 100b may include a porous substrate including a plurality of pores. Here, the porous substrate may be formed of a porous ceramic, a polymer fiber, a glass fiber, a metal foam, a metal fiber, or the like. The material of the porous ceramic may include at least one of zirconia (ZrO2), zeolite, silicon carbide (SiC), and cordierite. The material of the polymer fiber may include at least one of polyurethane, polypropylene, and polytetrafluoroethylene (PTFE). The material of the glass fiber may include at least one of borosilicate glass and soda-lime glass. The material of the metal foam or metal fiber may include at least one of nickel, aluminum, copper, brass, stainless steel, chromium, silver, gold, or an alloy thereof.

A plurality of porous layers 100a and 100b may be arranged in one direction FW to form a plurality of porous layers. The porous layers 100a and 100b may be provided in a plate shape of various shapes without limitation in shape, such as a circle or a square. In one embodiment of the present invention, the porous layers 100a and 100b are provided with two circular plate-shaped members.

The number of pores included in the porous layers 100a and 100b per unit inch (1 inch) is preferably 10 ppi to 200 ppi (pore per inch), and when converted into unit pore size, it is 2.54 to 0.12 mm level. Considering that the pore size of a typical HEPA filter is 0.03 mm, the pore size of the porous layer in this embodiment is larger than that of the HEPA filter. Through this, the back pressure can be formed to be less when the multilayer filter according to the present embodiment is used than when a general HEPA filter is used.

The number of pores included per unit inch in each of the plurality of porous layers 100a and 100b is preferably configured to increase or decrease according to the order in which they are arranged along the one direction FW. In detail, in an environment in which the multilayer filter in this embodiment is used, the flowing gas (Air) may move in one direction (FW), and the number of pores included per unit inch in each of the plurality of porous layers (100a, 100b) is It is preferably configured to increase along one direction. Since the number of pores included per unit inch increases, that is, the size of the pores decreases, the size of the pores increases toward the porous layer 100b adjacent to the side from which the fluidized gas is discharged rather than the porous layer 100a adjacent to the side into which the fluidizing gas is introduced. It can be filtered according to the flow of the flowing gas in the order of particles to small particles.

The perforated layers 200a, 200b, and 200c are disposed between at least two porous layers 100a and 100b adjacent to each other, and a perforation h penetrating between one surface and the other surface may be formed. The porous layers 200a, 200b, and 200c, like the porous layers 100a and 100b, may be provided in a plate shape of various shapes without limitation of a shape such as a circle or a square. However, according to the embodiment, it is preferable that the porous layers 200a, 200b, and 200c have the same shape as the porous layers 100a and 100b, and in an embodiment of the present invention, the porous layers 100a, 100b have the same circular shape. It is provided as a plate-shaped member of

Here, the perforation (h) may be formed to a size of several mm but penetrates between one surface and the other surface of the perforation layer (200a, 200b, 200c). Preferably, the size of the perforation (h) may be selected in the range of 1 mm or more and 5 mm or less. As a result, the fluidized gas enters the porous layers 200a, 200b, and 200c from the porous layer 100a on the side into which the fluidized gas flows, and the pressure is lowered to abruptly increase the flow rate, and also the porous layers 200a, 200b, 200c. ) while entering the porous layer 100b on the side where the flowing gas is discharged, the pressure is increased and the flow rate is rapidly decreased. Through this, it is possible to effectively induce the inertial impaction of the particles, thereby improving the filtration efficiency of the particles, especially the particles with large inertia compared to drag. The shape of the perforation (h) may be formed in various shapes without limitation of the shape, such as a circle or a square. For example, the shape of the perforation h may be circular as in the exemplary embodiment 1000 illustrated in FIG. 2 , or may be rectangular as in the other exemplary embodiment 1000 ′ illustrated in FIG. 3 .

A plurality of perforated layers 200a, 200b, and 200c may be provided and arranged in one direction FW.

It is preferable that at least some of the perforations h formed in the perforated layers 200a, 200b, and 200c are randomly arranged so that the phases between the perforated layers adjacent to each other do not coincide. Through this, the particles contained in the fluidized gas flowing into the porous layers 200a, 200b, and 200c from the porous layer 100a on the side through which the fluidizing gas flows can be efficiently filtered even in the porous layers 200a, 200b, 200c. .

The porous layers 200a, 200b, and 200c may be a porous substrate including a plurality of pores, like the porous layers 100a and 100b. Through this, the particles can be more efficiently filtered even within the perforated layers 200a, 200b, and 200c.

It is preferable that the number of pores included per unit inch in each of the plurality of perforated layers 200a, 200b, and 200c of the porous substrate increases or decreases according to the order in which they are arranged along the one direction FW. In detail, in the environment in which the multilayer filter in this embodiment is used, the flowing gas (Air) may move in one direction (FW), and the plurality of perforated layers (200a, 200b, 200c) of the porous substrate are contained per unit inch. Preferably, the number of pores is configured to increase along one direction. The number of pores included per unit inch increases, that is, the size of the pores increases toward the porous layer 200c of the porous substrate adjacent to the side from which the fluidizing gas is discharged rather than the porous layer 200a of the porous substrate adjacent to the side in which the fluidizing gas is introduced. Since it is reduced, it can be filtered according to the flow of the flowing gas in the order of the largest particles to the smallest particles. Here, the number of pores included per unit inch is in the order of the flow direction of the fluidized gas, that is, the porous layer 100a adjacent to the side to which the fluidized gas is introduced, the porous layer 200a, the porous layer 200b, the porous layer 200c, and the fluidized gas is discharged. It is preferable to increase in the order of the porous layer (100b) adjacent to the side to be.

4 is a schematic perspective view of a multilayer filter according to another embodiment of the present invention, and FIG. 5 is an exploded perspective view of the multilayer filter shown in FIG. 4 .

In the multilayer filters 1000 and 1000' according to one embodiment and another embodiment of the present invention, the porous layers 100a, 100b and the porous layers 200a, 200b, 200c, 200d have been mainly described in the form of a plate, but this As in the multilayer filter 4000 according to another embodiment of the present invention, the plurality of porous layers 4100a and 4100b and the porous layers 4200a, 4200b, 4300c, and 4400d may have a cylindrical shape.

The cylinder diameter of the porous layer 4100a adjacent to the side into which the fluidized gas is introduced may be the largest, and the cylinder diameter of the porous layer 4100b adjacent to the side to which the fluidized gas is discharged may have the smallest cylinder diameter. A porous layer (4200a, 4200b, 4200c, 4200d) is disposed between the two adjacent porous layers (4100a, 4100b), a plurality of porous layers (4100a, 4100b) and a plurality of porous layers (4200a, 4200b, 4200c, 4200d) The circular cross-sections of can be concentric with each other.

Hereinafter, the back pressure and filtration efficiency of the multilayer filter according to various embodiments of the present invention and the multilayer filter according to the comparative example compared thereto will be described in comparison.

Example

1) Prepare a disk-shaped porous substrate of nickel-chromium alloy metal foam having 10 to 200 PPI of pores per unit inch.

2) A 3 mm hole is formed in some disk-shaped porous substrates.

3) Three disk-shaped porous substrates (perforated layers 1 to 3) having perforations formed between the two disk-shaped porous substrates (porous layers 1 and 2) are arranged to constitute a laminated filter. Several examples of multilayer filters distinguished from each other according to the number of pores per unit inch of each layer were prepared as shown in Table 1 below. Here, the thickness of the porous layer was 17.5 mm, the thickness of the porous layer was 5 mm, and the diameter of the multilayer filter was 47 mm.

comparative example

1) Prepare a polypropylene HEPA filter manufactured by melt blown technique.

2) The HEPA filter assembly was finished with a polyurethane material after bending the fabric in a zigzag shape to maximize the permeation cross-sectional area. Here, the thickness of the HEPA filter fabric is about 0.5 mm, and the thickness of the HEPA filter assembly is 25.4 mm.

Experiment

1) After each of the laminated filter of Example and the HEPA filter assembly of Comparative Example was tightly arranged in a passage of 47 mm, incense was ignited to generate particles.

2) In Examples and Comparative Examples, the filtration efficiency was measured by measuring the particle concentration and pressure on the side where the flowing gas containing particles enters/discharges.

3) When the pressure on the side where the flowing gas enters is P1 and the pressure on the side where the flowing gas is discharged is P2, the back pressure can be defined as P1-P2, and the back pressure was measured with a differential pressure gauge (product name: Testo 510). .

4) Assuming that the particle concentration on the side where the flowing gas enters is M1 and the particle concentration on the side where the flowing gas is discharged is M22, the filtration efficiency can be defined as (M1-M2)/M1, and the particle concentration is Product name: TSI Aerotrack) was measured.

Experiment result

Number of pores per unit inch (1 inch) Back pressure (Pa) Filtration efficiency (%) porous layer 1 perforated layer 1 perforated layer 2 perforated layer 3 porous layer 2 Example 1 20 30 30 30 200 113 99 Example 2 20 30 30 30 100 98 99 Example 3 20 30 30 30 50 60 99 comparative example HEPA filter 310 99

In Examples 1 to 3, the filtration efficiency was maintained as high as 99% as in Comparative Examples, but it was confirmed that the back pressure was significantly reduced to 50% or less compared to Comparative Examples.

That is, according to the multilayer filter according to the embodiment of the present invention, there is an advantage that the back pressure can be greatly reduced compared to the filter of the prior art, while the filtration efficiency can be maintained high.

Although the present invention has been described with reference to the preferred embodiments thereof, various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover such modifications and variations as long as they fall within the gist of the present invention.

1000, 1000', 4000 : laminated filter
100a, 100b, 4100a, 4100b: porous layer
200a, 200b, 200c, 4200a, 4200b, 4200c, 4200d: perforated layer
h: perforation
FW: one way

Claims (10)

A porous substrate including a plurality of pores, comprising: a plurality of porous layers arranged in one direction; and
A perforated layer disposed between at least two adjacent porous layers and having a perforation penetrating between one surface and the other surface is included;
The size of the hole is,
It is selected from the range of 1 mm or more and 5 mm or less,
The flowing gas is
As the fluidized gas enters the porous layer from the porous layer on the inflow side, the pressure decreases and the flow velocity increases, and as the fluidized gas enters the porous layer on the side from which the fluidized gas is discharged from the porous layer, the pressure increases and the flow velocity decreases. which is a laminated filter. According to claim 1,
The number of pores included per unit inch (1 inch) in the porous layer is 10 ppi to 200 ppi (pore per inch), the multilayer filter. According to claim 1,
The number of pores included per unit inch in each of the plurality of porous layers increases or decreases according to the order in which they are arranged along the one direction, the multilayer filter. 4. The method of claim 3,
The flowing gas moves along the one direction,
The number of pores included per unit inch in each of the plurality of porous layers increases in one direction, the multilayer filter. According to claim 1,
A plurality of the perforated layers are provided and arranged along the one direction, the multilayer filter. 6. The method of claim 5,
At least some of the perforations formed in the perforated layer are randomly arranged so that the phases between the perforated layers adjacent to each other do not coincide. 6. The method of claim 1 or 5,
The porous layer is a porous substrate including a plurality of pores, the laminated filter. 8. The method of claim 7,
The number of pores included per unit inch in each of the plurality of perforated layers of the porous substrate increases or decreases according to the order in which they are arranged in the one direction, the multilayer filter. According to claim 1,
The plurality of porous layers and the porous layer are plate-shaped, laminated filter. According to claim 1,
The plurality of porous layers and the porous layer are cylindrical.

Images