JPH07213944A - Air purification filter - Google Patents

Abstract

PURPOSE:To prevent leaked electric current and spark discharge from being generated even when the electric insulation resistance of a filter medium is decreased due to adsorbed water on the filter medium in an electrostatic air purification filter. CONSTITUTION:A high electric voltage side electrically-conductive part 2 and an earth side electrically-conductive part 3 are arranged at a specified gap on a filter medium 1 consisting of an air-permeable electrical insulating material 1 and the high electric voltage side electrically-conductive part 2 is provided with an electric insulating coating to form an air purification filter 10. Leaked electric current and spark discharge are thereby prevented from being generated even when the electric insulation resistance of the filter medium 1 decreases.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purification filter for collecting dust in the air to purify the air.

[0002]

2. Description of the Related Art As an air purifying filter for purifying air by collecting dust in the air, there is a charge-type filter disclosed in JP-A-63-36852. In this charge filter, conductive parts are arranged at asymmetrical positions on the front and back of the filter medium, the conductive part arranged on the inflow side of the air flow is the ground side, and the conductive part arranged on the outflow side of the air flow is the high voltage side. An electric field is formed between the high-voltage side conductive portion and the ground-side conductive portion to charge the dust and the filter medium, thereby collecting the dust in the air by the electrostatic action.

[0003]

On the other hand, in the above charge type filter, neither the high voltage side conductive portion nor the ground side conductive portion is electrically insulated, so that the charge type filter is used in a high humidity atmosphere or a wet atmosphere. If so, water is adsorbed on the filter medium and the electrical insulation resistance between both conductive parts is reduced, so that power consumption increases due to leakage current, and spark discharge occurs between both conductive parts, and in some cases trapped by the filter medium. There is a problem that the collected flammable dust is ignited and ignited.

The present invention has been made in view of the above problems, and by electrically insulating at least the high-voltage side conductive portion, moisture is adsorbed on the filter medium to lower the electric insulation resistance between the conductive portions. However, it is an object of the present invention to obtain an air purification filter that does not generate a leak current and a spark discharge between both conductive parts.

[0005]

In order to achieve the above-mentioned object, the present invention provides a filter medium made of an electrically insulating material having air permeability, and a high-voltage side conductive portion arranged in the filter medium with a predetermined gap. And a ground side conductive portion, and at least the high voltage side conductive portion of the both conductive portions is electrically insulated and coated with a non-water-absorbing electrical insulating material.

Further, it is effective to heat-weld the electrically insulating coating to the filter medium. Further, it is effective to use the same material as the filter medium for the electric insulation coating portion.

[0007]

According to the above means, since the high voltage side conductive portion and the ground side conductive portion are arranged in the filter medium with a predetermined gap therebetween, when the high voltage is applied to the high voltage side conductive portion, the filter medium is A strong electrostatic charge is generated in the dust, and dust in the air is attracted to the filter medium by the electrostatic force and is collected in the pores of the filter medium. In this case, even if moisture is adsorbed on the filter medium and the electrical insulation resistance of the filter medium is reduced,
Since the high-voltage side conductive portion is coated with a non-water-absorbing electric insulating coating, the generation of leak current and spark discharge between the conductive portions is suppressed by this electric insulating coating.

Further, the electrically conductive portion is firmly fixed to the filter medium by heat-welding the electrically insulating coating to the filter medium.
Furthermore, the heat-welding property is improved by using the same material as the filter medium for the electrically insulating coating.

[0009]

Embodiments of the air purifying filter of the present invention will be described below with reference to the drawings. FIG. 1 shows an air purification filter 10
FIG. 1 shows an embodiment of the present invention, in which 1 is a plate-shaped filter medium made of an electrically insulating material having a high dielectric constant such as polypropylene or polyester, which has air permeability necessary for practical use. The high voltage side conductive portion 2 in which one side of the filter medium 1 is provided with an electric insulation coating described later.
The ground-side conductive portion 3 is arranged on the opposite surface of the filter medium 1, and both conductive portions 2 and 3 are arranged so as to be displaced from the facing position. In addition, 2a is an end of the high voltage side conductive part 2 and 3a is an end of the ground side conductive part 3 for electrically connecting to a terminal described later.

In order to increase the surface area of the air purifying filter 10, FIG. 2 is bent in a corrugated shape as is well known, and the bent portion is bent so as to avoid the positions where both conductive portions 2 and 3 are arranged. . FIG. 3 shows a folded air purification filter 10
2 shows an air purification filter unit 20 in which a bent air purification filter 10 is fitted into a frame 4 made of resin, and an end portion 2a (see FIG. 2) is electrically connected to the high voltage side terminal 5. The end portion 3a (see FIG. 2) is electrically connected to the ground side terminal 6.

FIG. 4 shows an example of the cross-sectional shape of the high-voltage side conductive portion 2 provided with an electric insulation coating. The conductive wire 2a is made of copper or aluminum and has a circular, elliptical, or quadrangular cross-section. An electric insulating coating 2b, which is preferably made of the same material as the filter medium 1 such as polypropylene or polyester and has no water absorption property, is provided. Where conductor 2
Although the dimension of a can be set arbitrarily, it may be set to such an extent that the ventilation resistance of the filter medium 1 does not hinder the practical use due to the relationship of the arrangement gap between the conductive portions 2 and 3 arranged in the filter medium 1. Also,
The thickness of the electric insulation coating 2b can be set arbitrarily, but it is sufficient if it is thick enough to withstand the maximum voltage applied practically under the condition of being exposed to water.

FIG. 5 shows the high voltage side conductive portion 2 for the filter medium 1.
And an arrangement example of the ground side conductive part 3 are shown. One in which the high voltage side conductive part 2 is arranged on one side of the filter medium 1 and the ground side conductive part 3 is arranged on the opposite side of the filter medium 1 It is divided into one in which the high-voltage side conductive portion 2 and the ground-side conductive portion 3 are arranged only on one side with a required gap. FIG. 6 shows the heat welding of the electric insulation coating 2b applied to the conducting wire 2a to the filter medium 1. As shown in FIG. 6 (A), the elastic receiving portion is provided with the electric insulation coating 2b. The conductive portion 2 is placed, the filter medium 1 is placed on the conductive portion 2, and the conductive portion 2 is pressed from above the filter medium 1 by the heating and pressing portion, so that the filter medium 1 is electrically conductive as shown in FIG. 6B. The electric insulation coating 2b of the part 2 is heat-welded.

The heat-welding is performed spotwise with a predetermined gap, and the conductive portion 2 is firmly fixed to the filter medium 1 through the electric insulating coating 2b. In this case, it is particularly important that the electric insulation coating 2b is heat-welded so as not to be broken. FIG. 7 shows the air purification filter unit 20 incorporated in an air conditioner. Inside the air conditioning case 21, an inside air / outside air switching damper 24 for switching to the inside air introduction port 22 side or the outside air introduction port 23 side, and the inside air Alternatively, a blower 25 that introduces outside air and blows it downstream, and an evaporator 2 that cools the air
6 and a heater core 27 for heating air, and a temperature control damper 28 for varying the ratio of cold air and warm air are sequentially arranged.

Here, the air purification filter unit 20
As shown in the figure, it is desirable to arrange it on the upstream side of the evaporator 26 where it is easy to obtain a large air passage area. Furthermore, it is possible to prevent foreign substances from adhering to the evaporator 26 and the heater core 27, which may cause a strange odor. For this reason, it is desirable to install it on the upstream side of the evaporator 26.

Next, the operation of the above embodiment will be described. In FIG. 3, the air purification filter unit 2
When the ground-side terminal 6 of 0 is grounded and a high voltage is applied to the high-voltage side terminal 5, an electric field is formed between the high-voltage side conductive portion 2 and the ground-side conductive portion 3, so that the filter medium 1 is strong. An electrostatic charge is generated, dust in the air is attracted to the filter medium 1 by the electrostatic force of the filter medium 1, and the dust is collected in the pores of the filter medium 1.

Here, as shown in FIG. 7, when the air purifying filter unit 20 is used in an air conditioner in a flooded environment, moisture is adsorbed on the filter medium 1 to electrically insulate the conductive parts 2 and 3 from each other. Even if the resistance decreases, the high-voltage side conductive portion 2 is provided with the non-water-absorbing electric insulating coating 2b (see FIG. 4),
Since the occurrence of leak current and spark discharge between both conductive parts 2 and 3 is suppressed, a rapid increase in power consumption and ignition due to ignition of collected dust are prevented.

Further, the electric insulation coating 2 of the high voltage side conductive portion 2
Since b is heat-welded to the filter medium 1, the high-voltage side conductive portion 2 is firmly fixed to the filter medium 1, and thus vibration resistance is improved. Further, by making the material of the electric insulating coating 2b the same as the material of the filter medium 1, the heat welding of the electric insulating coating 2b to the filter medium 1 is facilitated and the quality of heat welding is improved. next,
In the present embodiment, the high-voltage side conductive portion 2 is electrically insulation-coated and heat-welded to the filter medium 1. However, the ground-side conductive portion 3 is also electrically-insulated as in the high-voltage side conductive portion 2 and heat-welded to the filter medium 1. You may.

When the ground-side conductive portion 3 is electrically insulated and is not heat-welded to the filter medium 1, the ground-side conductive portion 3 is adhesively fixed to the filter medium 1 with an adhesive in view of vibration resistance. desirable.

[0019]

Since the present invention is configured as described above, in the air purifying filter of claim 1 which has the following effects, the filter medium has a moisture content adsorbed thereon, so that the electrical insulation resistance of the filter medium is increased. Even if the voltage drops, the high-voltage side conductive portion is electrically insulated, so that the generation of leak current and spark discharge can be suppressed, so that a rapid increase in power consumption and ignition due to ignition of collected dust can be prevented.

In the air purifying filter of claim 2,
Since the conductive part is firmly fixed to the filter medium by heat welding through the electrically insulating coating part, the vibration resistance is improved. In the air purifying filter of the third aspect, since the same material as the filter medium is used for the electrically insulating coating, heat welding is facilitated and heat welding quality is improved.

[Brief description of drawings]

FIG. 1A is a plan view showing an embodiment of an air purification filter, and FIG. 1B is a side view.

2 (A) is a plan view of the air purification filter of FIG. 1 after bending, and FIG. 2 (B) is a side view.

3A is a plan view of a unit incorporating the air purification filter of FIG. 2, and FIG. 3B is a side view.

4 (A), (B), (C) and (D) are cross-sectional views showing various shapes of a high voltage side conductive portion.

5 (A) and 5 (B) are plan views showing various arrangements of conductive parts of the air purification filter.

FIG. 6A is a cross-sectional view of a high-voltage side conductive portion and a filter medium before heat welding, and FIG. 6B is a cross-sectional view after heat welding.

FIG. 7 is a schematic cross-sectional view in which an air purification filter unit is incorporated in an air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filter medium 2 High-voltage side conductive part 2b Electric insulation coating 3 Ground side conductive part 10 Air purification filter

Claims (3)

[Claims] 1. A filter medium comprising an electrically insulating material having air permeability, and a high voltage side conductive portion and a ground side conductive portion which are arranged in the filter medium with a predetermined gap therebetween. An air purifying filter, wherein at least the high-voltage side conductive portion is electrically insulating coated with a non-water-absorbing electrical insulating material. 2. The air purification filter according to claim 1, wherein the electrically insulating coating is heat-welded to the filter medium. 3. The air purification filter according to claim 1, wherein the electrically insulating coating portion is made of the same material as the filter medium.