JPH04108510A - Air cleaning filter - Google Patents

Abstract

PURPOSE:To lower pressure loss with respect to turblent flow by using a three- dimensional knit article consisting of polygonal reticulated cells having air permeable partition walls as a core and filling the cells with a granulated adsorbent and bonding reticulated air permeable sheets to both surfaces of the knit article. CONSTITUTION:A three-dimensional article 1 consisting of polygonal reticulated cells 7 having air permeable partition walls 5 is used as a core and the cells 7 are filled with an adsorbent 6 such as granulated activated carbon and reticulated air permeable sheets 8 are bonded to both surfaces of the three-dimensional knit article 1. As a result, in realizing an air cleaner of low noise and large air quantity, a flexible air cleaning filter reduced in pressure loss with respect to laminar flow and turblent flow in practical use can be obtained.

Description

[Detailed Description of the Invention] Industrial Application Fields Demands for dust collection and deodorization in general households are becoming stronger year by year. It is increasing in proportion to the improvement in the degree of airtightness of buildings and the spread of air conditioning equipment.

The present invention is based on such a request (and relates to an air purifying filter used in an air purifier).

BACKGROUND OF THE INVENTION The conventional method for this type of filter has been to fill a flat or zigzag filter case with granular adsorbent. This method has drawbacks such as the filling rate changes due to transportation, vibration, etc., the generation of fine powder and dirt, and the flow path of the processing fluid changes, making it no longer able to achieve its initial purification performance. .

Furthermore, in order to compensate for these drawbacks, various filter processing methods have been proposed in recent years. That is, as shown in FIG. 8, granules of adsorbent 32 are directly sprinkled on a thermoplastic resin nonwoven fabric 31 and bonded under heat to form a filter, or as shown in FIG. The adsorbent 32 is bonded to a nonwoven fabric, a three-dimensional mesh elastic sheet 33, or the like by selecting a type of adhesive. Of these, the former has drawbacks such as a weak bonding force between the adsorbent 32 and the non-woven fabric 31, and the components attached to the adsorbent deteriorate due to heat during heating. Also, the air pressure drop was high. In the latter case, since adhesives are used, solvents and solutes can have a considerable effect on the adsorption capacity of the adsorbent, resulting in decreased adsorption capacity, uneven distribution of the adsorbent, and the need to reduce the amount of adsorbent used. If the amount is increased, there are drawbacks such as an increase in pressure loss.

Therefore, the present inventors have previously proposed an air purifying filter that solves the above-mentioned drawbacks.

The configuration will be described below with reference to FIGS. 10 to 12. The honeycomb-shaped base material 34 is made of a thin aluminum plate or kraft paper hardened with a phenolic resin or the like. Air purification filters are
Putting the adsorbent 36 into the cells 35 of the honeycomb-shaped base material 34,
A nonwoven fabric 38 is bonded to both sides with a spider web-like adhesive sheet 9.

Problems to be Solved by the Invention However, in this air purifying filter, fine particles are usually included as the adsorbent 36 inside the filter, so the fiber basis weight of the nonwoven fabric 38 must be increased.
The disadvantage was that the pressure drop was high. In addition, the pressure drop is relatively low for laminar air flow, but there is a problem that the pressure drop is high due to lateral flow and turbulent flow that occur in actual use as they collide with the honeycomb walls. Furthermore, since such a honeycomb-shaped base material is hard, there is also the problem that the filter has poor flexibility and is limited in shape.

The present invention solves the above-mentioned problems, and the first purpose is to realize a low-noise, large-airflow air purifier that has low pressure drop and flexible air purification for laminar flow and turbulent flow in actual use. In addition to the first objective, the second objective is to provide an air purifying filter that further reduces pressure loss and has high shape retention.

Means for Solving the Problems In order to achieve the above-mentioned first object, the present invention uses a three-dimensional knitted fabric consisting of polygonal mesh cells having air-permeable partition walls as a core, and granulated activated carbon or the like in the cells. Add the adsorbent,
and a mesh-like breathable sheet is pasted on both sides of the three-dimensional knitted material, and in order to achieve the second object, the three-dimensional knitted material is made of a three-dimensional knitted material consisting of polygonal mesh cells having breathable partition walls as a core, At least one diagonal side of the front and back polygons is connected with a connecting thread, an adsorbent such as granulated activated carbon is placed in the three-dimensional knitted fabric, and a mesh-like breathable sheet is placed on both sides of the three-dimensional knitted fabric. It is made by pasting them together.

Effect of the present invention With the above structure, the granulated adsorbent has a relatively uniform particle size and does not contain fine particles, so even if the breathable sheet covering both sides is in the form of a mesh, the adsorbent will not leak. Therefore, the pressure loss of the air purifying filter can be extremely reduced. Furthermore, since the core is made of three-dimensional knitted fabric and the partition walls of polygonal mesh cells are breathable, the pressure drop of the air purifying filter can be lowered, especially against turbulence that occurs during actual use, and the filter is flexible. It can be done.

Further, in the present invention, a three-dimensional knitted fabric consisting of polygonal mesh cells having breathable partition walls is used as a core, and at least one diagonal side of the upper and lower polygons is connected with a thread, and the three-dimensional knitted fabric is Since adsorbents such as activated carbon are added to the
It is possible to make a filter with high shape retention, and
By making the filter thicker, the density of the adsorbent can be made coarser, thereby further reducing the pressure drop.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5. The three-dimensional knitted fabric l serving as the filter base material is composed of cells in the form of a polygonal mesh, the front and back polygonal meshes 2 and 3 knitted with twisted yarn are connected in parallel with a connecting thread 4, and has an air-permeable partition wall 5. be. Here, the front and back polygonal nets 2 and 3
is made of twisted polyester yarn, and the connecting yarn 4 is a single nylon yarn. The cell size is generally expressed as one dimension, and this one dimension and the C dimension greatly affect the performance of the filter. In other words, the optimum dimensions are set based on the particle size of the adsorbent 6 such as activated carbon, the amount used, and the pressure drop. Generally, one dimension is 2 mm to 1.5 mm (12 m in the example)
m), and C dimension of 3 mm to 20 mm (7 mm was used in the example) is easy to use. The filter A is made by putting an adsorbent 6 into the self of such a three-dimensional knitted fabric 1, a mesh-like breathable sheet 8 on both sides, and a spider web-like adhesive sheet 9.
It is joined with As the adsorbent 6, granulated ordinary activated carbon, activated carbon impregnated with a chemical effective against odor components, zeolite, silica, alumina, etc. are used. The particle size of the adsorbent 6 is determined based on the adsorption capacity, but generally extruded cylindrical products with a diameter of 2 mm to 4 mm and a length of 2 mm to 7 mm, and spherical particles with a diameter of 2 mm to 5 mm are used. used. In the examples, granulated coal having a diameter of 2 mm and a length of 2 mm to 5 mm was used. The type of adsorbent 6 is 1
Although one species or two or more species may be selected, in the example, four species were selected: one for aldehydes, one for ammonia, one for sulfur, and one for hydrocarbons.

Next, the breathable sheet 8 is made of polyester, acrylic, PP,
A woven fabric made of thermoplastic resin such as PE, the thickness of each loose thread is approximately 0.5 mm, and the pitch between loose threads is approximately 1.5 m.
Use m. Here, acrylic fibers that had been previously subjected to conductive treatment were used as the breathable sheet 8 in order to serve as electrodes during electrostatic precipitation. Conductive is breathable sheet 8
It is sufficient that the conductivity is IKΩ/c+
I made it below i.

As the adhesive sheet 9 for joining the three-dimensional knitted fabric 1 and the breathable sheet 8, a solvent-free heat-welding resin (nylon-based,
Acrylic, polyester, etc.) are made into fibers and a nonwoven fabric with a high aperture ratio, that is, a (nest-like adhesive sheet) is used.

As a processing procedure, first, three-dimensional knitted fabric 1 and breathable sheet 8
are bonded on only one side using a spider web-like adhesive sheet 9 by hot pressing or the like, and then the adsorbent 6 is uniformly sprinkled thereon. Next, the filter A is completed by applying vibration and leveling with a spatula, placing a spider web-shaped adhesive sheet 9 on top, placing a breathable sheet 8 on top, and heating with a hot press or the like. The hot press conditions are 135 here.
°C x 4 to 5 seconds.

The air purifying filter A obtained in this way is 4'
54 mm x 302 mm x thickness approx. 7.5 m
m, the amount of adsorbent 6 is about 300 g, and is used in an actual air purifier as shown in FIGS. 10 is an air inlet, 11 is an air outlet, 12 is a control section, and 13 is a jig for setting a filter. Filter A for air purification is set using a jig 13 as shown in FIG. 14 is a pre-filter for removing large dust particles in the air; 15 is an electrostatic precipitator filter; 16 is a motor;
7 is a fan section, and 18 is an air flow path. Reference numeral 19 denotes a discharge electrode of a positive electrode for generating high voltage for electrostatic precipitate, and the conductive portion on at least one side of the filter A functions as its counterpart. 20 is the body of the air purifier.

The operation of the air purifier with the above configuration will be described. As the fan section 17 rotates, air is sucked in from the air suction ports 10 on both sides, and large dust particles are first removed by the pre-filter 14. Subsequently, fine dust and smoke are positively charged by the corona discharge of the discharge electrode 19, and are captured by the electrostatic precipitator filter 15. Thereafter, gas components such as odors are adsorbed by the adsorbent 6 of the filter A, and purified air exits from the air outlet 11.

Note that (instead of the web-like adhesive sheet 9, hot-melt resin may be directly applied to the polygonal meshes 2 and 3 on the front and back sides of the three-dimensional knitted fabric 1 by spraying, or an adsorbent 6 may be used).
The breathable sheet 8 may be joined by applying an adhesive within a range that does not affect the air permeable sheet 8.

Next, another embodiment of the present invention will be described with reference to FIG. 6.7. The three-dimensional knitted fabric 21 serves as a filter base material, and the difference between the three-dimensional knitted fabric 1 of the previous embodiment is that the polygonal nets 2 and 3 on the front and back sides are connected in parallel with a connecting thread 4, and at least one of the polygons on the front and back sides is connected in parallel. A cell 23 is formed by connecting two diagonal sides with a connecting thread 22. In this embodiment, a single nylon yarn was used as the connecting yarn 22. Also cell 2
The first dimension of 3 is 12 mm, which is the same as in Example 1, and the C dimension is 10
mm. In the cell 23 of such a three-dimensional knitted fabric 2I, as in the previous example, there are four types of diameters of 2 mm, one for aldehyde, one for ammonia, one for sulfur, and one for hydrocarbon.
, granulated carbon having a length of 2 mm to 5 mm was put therein, and a breathable sheet 8 was bonded to both sides with a web-like adhesive sheet 9.

The air purification filter obtained in this way is 454 m long.
The size is 302 mm x 10.5 mm, and the amount of adsorbent 6 is about 300 g, which is used in an actual air purifier as shown in Fig. 4.5. Although the filter of this embodiment is thicker than that of the previous embodiment, since there is a connecting thread 22 on at least one diagonal side of the front and back polygons, the adsorbent 6 will not be displaced due to vibration or the like. In addition, it is flexible and has good shape retention.

Next, the filter of Example 1.2 and FIGS.
We compared the pressure drop of filters using crushed coal shown in the figure and conventional honeycomb cores made of kraft paper. In the filter of the comparative example, the dimensions of the kraft paper cells were as in Example 1.2.
The adsorbent 36 is 12 mm, the same as in Example 1, and the thickness is 7 mm, and the adsorbent 36 is 6 Mesh to 12 Mesh (approximately 4 mm to 2 mm) for aldehydes, ammonia, sulfur compound systems, and carbonization. 300 g of four types of crushed charcoal for hydrogen was used. Moreover, the nonwoven fabric 38 is polyester,
acrylic.

A fibrous nonwoven fabric made of thermoplastic resin such as PP and PE and having a basis weight of 30 g/d was used.

The spider web-like adhesive sheet 9 was also the same as in Examples 1 and 2, and the dimensions of the filter were 454 mm x 302 mm.

The pressure drop was evaluated when the filter alone was measured in laminar flow at a flow rate of 1 m/sec, and when it was installed in the air purifier shown in Figures 4 and 5 and operated at a flow rate of approximately 0.4 m/sec. went. The results are shown in Table 1.

(Margin below) Table 1 As is clear from the results, the filters of the examples of the present invention all have lower pressure losses than the filters of the comparative examples. Among them, Example 2, which has a thick filter, has a low pressure loss. These effects are particularly noticeable when installed in an air purifier where turbulence occurs. Furthermore, by applying antibacterial and antifungal treatment to each breathable sheet, it is possible to suppress the growth of germs, bacteria, mold, and the like.

Effects of the Invention As is clear from the above examples, according to the present invention, one part consists of a granulated adsorbent and a breathable sheet, and the second part consists of polygonal mesh cells having breathable partition walls. Since the three-dimensional knitted fabric is used as the core, it is possible to provide a flexible air purifying filter with low pressure loss against laminar turbulent flow in actual use. Furthermore, since at least one diagonal side of the polygon on the front and back sides of the core is connected with a connecting thread, it is possible to further reduce pressure loss (and provide an air purifying filter with high shape retention). Furthermore, the air purifying filter according to the present invention enables an air purifier with low noise and large air volume.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the basic structure of an air purifying filter according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of section B in FIG. 1, and FIG. 3 is a perspective view of the three-dimensional knitted material in FIG. 1. figure,
4 and 5 are perspective views and sectional views of an air purifier in which the air purifying filter of the present invention is used, and FIG. 6 is a partially enlarged sectional view of an air purifying filter that is another embodiment of the present invention. Figures 7a and 7b are a perspective view and a partial sectional view of the three-dimensional knitted fabric in Figure 6, Figures 8 and 9 are sectional views showing the configuration of a conventional filter, respectively, and Figure 10 is a conventional filter. A sectional view of the proposed filter, FIG. 11 is an enlarged sectional view at part 0 of FIG. 10, and FIG. 12 is a perspective view of the honeycomb-shaped base material in FIG. 10. 1.21...3D knitting, 4,22...Connecting thread, 5
...Breathable bulkhead, 6...Adsorbent, 8...Breathable sheet, 7.23...Cell, Name of agent: Patent attorney Haruaki Ogata and 2 others Kekisatsu Sea F No. Figure ■ Figure Figure

Claims (2)

[Claims] (1) A three-dimensional knitted fabric consisting of polygonal mesh cells with breathable partition walls is used as a core, an adsorbent such as granulated activated carbon is placed in the cells, and a mesh-like breathable sheet is placed on both sides of the three-dimensional knitted fabric. Air purification filter made by laminating together. (2) A three-dimensional knitted fabric consisting of polygonal mesh cells with breathable partition walls is used as a core, at least one diagonal side of the front and back polygons is connected with a connecting yarn, and granulation is carried out in the three-dimensional knitted fabric. An air purifying filter comprising an adsorbent such as activated carbon, and a mesh-like breathable sheet pasted on both sides of the three-dimensional knitted fabric.