JPH05317750A - Air purifier - Google Patents

Abstract

PURPOSE:To prevent leakage of voltage or discharge, and improve collection performance by covering completely the surface of an electrode with insulating material. CONSTITUTION:In an air purifier, wherein air is passed by means of a blower means through between electrodes 10 to which high voltage is applied so that particles in the air are attracted toward the electrodes 10 and collected, and the surface of the electrodes 10 is covered completely with insulating material 12. As a result, even when high voltage is applied to the electrodes, leakage or discharge is prevented from occurring between the electrodes 10, resulting in improved collection performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cleaning device in which the surface of an electrode is covered with an insulating material to prevent voltage leakage and discharge.

[0002]

2. Description of the Related Art Conventional air purifiers for purifying air by collecting dust in the air use a filter medium, an electric dust collecting cell, or a combination thereof. There is. In an air purifier using a filter material, a filter material made of an insulating material is sandwiched between wires or mesh made of a conductive material, a voltage is applied to one wire or mesh, and the other wire or mesh is reversely applied. There is a type in which a dust collecting effect is enhanced by charging a filter medium by a dielectric effect by applying a voltage or grounding.

Further, in an air cleaning device using an electrostatic precipitator cell, a voltage is applied to a wire or needle electrode made of a conductive material and a plate-shaped metal electrode to generate corona discharge between them. There is a device in which particles in the air are charged by means of the above, and the charged particles are adsorbed to the plate-shaped metal electrodes to be collected, and a filter material made of an insulating material is sandwiched between the plate-shaped metal electrodes. Accordingly, a device in which the dielectric effect between the metal electrodes is increased to increase the collection efficiency of charged particles has been put into practical use.

[0004]

In the former filter medium sandwiched between wire rods and nets to give a potential difference to the wire rods and nets, the particle trapping performance of the filter medium is mainly due to the dielectric properties of the filter medium. Rate and strength of the electric field, occupancy in the electric field, fiber diameter of the fibers forming the filter medium, etc., the higher the dielectric constant,
Also, the stronger the electric field, the more the charge due to polarization of the dielectric increases,
The higher the ratio of the space in which the electric field exists to the dielectric, the stronger the electric field in the remaining space, and the more the polarization effect of the particles increases.

Further, the finer the fiber, the larger the surface area of the filter material, so that the electric charge generated by the polarization increases and the particle collecting performance increases. For this reason, a filter medium with a high permittivity and a small fiber diameter and a high density is usually placed in a strong electric field. In this case, however, the fiber diameter and density of the filter medium also increase the pressure loss of the filter medium, so it is too thin and high in density. The material cannot be used. Therefore, it has been attempted to increase the surface area of the filter medium by bending the filter medium in a pleated shape to reduce the pressure loss.However, since the dielectric constant of the filter medium is a characteristic peculiar to the material, this method The rate cannot be changed.

On the other hand, as a method of relatively easily increasing the strength of the electric field, there is a method of increasing the applied voltage between the electrodes. However, when the electric field exceeds 600 V / mm, the air between the electrodes causes dielectric breakdown. Discharge starts and the strength of the electric field does not rise.On the contrary, as the electric current increases like spark discharge, the electric field is significantly attenuated, which reduces the particle collection performance and reduces the ozone generated by the discharge ( O ₃ ) causes problems such as deterioration of the environment. In addition, the electric field is 600 V / m
Even if it is set to about m, if the filter medium is contaminated during use, electric current will flow through the surface of the contaminated filter medium due to moisture in the air and current will flow between the electrodes, weakening the electric field and collecting particles. Will fall. In addition, even when using a charging filter that has been subjected to permanent electrification treatment on the filter medium, the dirt will cause the electric charges on the surface of the filter medium to be consumed, reducing the electric field strength and electrical attractive force inside the filter medium and reducing the particle collection performance. There is a problem that drops.

On the other hand, in the latter air cleaning apparatus using the electrostatic precipitator cell, the distance between the electrodes is determined by the strength of the dielectric breakdown of air. Therefore, the particle charging electrode is set to a distance at which corona discharge occurs with respect to the other reverse potential electrodes, and the dust collecting plate electrodes are set to a distance at which discharge does not occur to the reverse potential electrodes arranged in parallel with each other. Also, there is a device in which a plate or filter material made of an insulating material is inserted on the side of the dust collecting electrode to improve the efficiency of collecting particles on the insulating material by dielectric polarization.
The distance between the electrodes is determined by the spatial distance between the electrodes.
Therefore, even if a plate with a large area is inserted and the electrodes are separated from each other, since this is a dust collection part, dirt accumulates as the dust collects, and the high voltage applied to the electrode propagates through the dirt and is closest to the reverse potential electrode. Discharge starts from the place.

Particularly in an air cleaning device using an electrostatic precipitator cell, excessive discharge generates a large amount of ozone,
It is necessary to minimize the amount of discharge other than particle charging. Therefore, in the conventional air purifier, it is necessary to frequently clean the filter medium, so maintenance is troublesome, and if the cleaning is neglected, excessive discharge to spark discharge may cause a fire. was there. The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide an air cleaning device that prevents voltage leakage and discharge by coating the surface of an electrode with an insulating material. ..

[0009]

In order to achieve the above object, the present invention draws air particles between electrodes to which a high voltage is applied by air blowing means so that particles in the air are attracted to the electrode side and trapped. In an air purifier that is designed to collect
The surface of the electrode is coated with an insulating material.

[0010]

With the above structure, even if a high voltage is applied between the electrodes, voltage leakage or discharge does not occur, and particles in the air can be efficiently collected by the strong electric field.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. FIG. 1 is a cross-sectional view of the air cleaning apparatus. In this figure, a housing 2 is a filter medium provided on the side of an intake port 3 opened at one end of the housing 1, and is provided on the upper surface of the housing 1. By opening the lid 4 of the filter material outlet 1a, it can be easily attached and detached. Reference numeral 5 denotes a blower fan installed in the casing 1, which is rotated by an electric motor 7 attached to the casing 1 via a bracket 6. The blower fan 5 causes the casing to pass through the filter medium 2. The air sucked into the body 1 is exhausted from an exhaust port 8 opened on the other end side of the housing 1.

On both sides of the filter medium 2, electrodes 10 made of a wire or mesh formed of a conductive material are provided, and the filter medium 2 is sandwiched between these electrodes 10 and the electrodes 10 are connected to each other. A high voltage is applied to the high voltage power supply device 11 installed in the housing 1.

On the other hand, the surface of the electrode 10 is covered with an insulating substance 12 such as plastic having a high dielectric constant and a high dielectric breakdown strength as shown in FIG. As a method of covering the electrode 10, a net-like electrode 10 made of a conductive substance is used.
After forming the electrode 10, a method of coating the surface of the electrode 10 with the insulating substance 12 to a thickness of about 1 mm, or forming a net with a wire coated with the insulating substance 12 in advance can be adopted. The end portion of the net body is formed by bending the wire rod as shown in FIG. 3 without cutting the wire rod so as not to be exposed.

Next, the operation of the air cleaning apparatus of the first embodiment having the above-mentioned structure will be described. A high voltage is applied to the electrodes 10 provided on both sides of the filter medium 2 by the high voltage power supply device 11 as shown in FIG. Is being applied. As a result, the filter medium 2 is charged by the dielectric effect. In addition, since the surface of each electrode 10 is covered with the insulating substance 12, dielectric breakdown does not occur between the electrodes 10 even when a high voltage is applied.

Incidentally, an electrode not covered with an insulating material has a dielectric breakdown strength of 600 V / mm, whereas an electrode covered with a polyethylene resin has a capacity of 18,000-2.
8,000 V / mm, 10,000 to 30,000 V / mm for electrodes coated with soft polyvinyl chloride, 12,000 to 16,000 for electrodes coated with phenolic resin
If the distance between the electrodes is the same, such as when a dielectric breakdown strength of V / mm is obtained, it becomes possible to apply a voltage as high as 20 to 50 times to the electrode not covered with the insulating material.

As described above, while the filter medium 2 is charged by the high voltage, the blower fan 5 is rotated by the electric motor 7 to suck air through the intake port 3, and when the air passes through the filter medium 2, the air in the air is removed. The dust particles are collected by the charged filter medium 2 and strongly collected. The air from which the particles in the air have been removed is discharged from the exhaust port 8 to the atmosphere.

On the other hand, even if the filter medium 2 is soiled or moist air passes through the filter medium 2 during long-term use,
Since the dielectric breakdown strength between the electrodes 10 covered with the insulating substance 12 is large, voltage leakage or discharge does not occur due to dirt or humidity, and the particles attached to the filter medium 2 also have an electric charge on the surface thereof. As a result, the particles function as a filter medium, and as a result, particles that can be retained in the filter medium 2 are saturated, or stable collection performance can be obtained until the filter medium 2 is clogged.

Although the electrode 10 has a mesh shape in the first embodiment, it may have a plate shape as in the second embodiment described below. That is, the plate-shaped electrodes 20 stacked in the vertical direction with a gap therebetween are housed, and a high voltage is applied to the plate-shaped electrodes 20 by the high-voltage power supply device 21. Similar to the first embodiment, the surface of the plate electrode 20 is also covered with the insulating material 12, and a plurality of metal wires, to which a high voltage is applied by the high voltage power supply device 22 for discharging, are provided in the intake port 3 of the housing 1. Book wire electrode 2
3 is stretched.

As a result, as shown in FIG.
In the meantime, corona discharge occurs, and particles in the air passing between these wire electrodes 23 are charged. When the charged particles pass through the electric field between the plate electrodes 20, the plate electrodes 20
Collected by. Further, as shown in FIGS. 7 and 8, by interposing the filter medium 2 made of an insulating material in a wave shape between the plate-shaped electrodes 20, particles can be collected in the filter medium 2.

In the second embodiment as well, as in the first embodiment, by covering the plate electrode 20 with the insulating material 12, no dielectric breakdown occurs even when a high voltage is applied, so that leakage or discharge does not occur. Particles in the air can be strongly collected without being generated, and the plate-shaped electrode 2 can be used for a long time.
Even if 0 is contaminated with particles, there is no concern that a fire will occur due to discharge.

[0021]

As described above in detail, according to the present invention, since the surface of the electrodes is coated with the insulating material, the dielectric breakdown strength between the electrodes is significantly increased. Therefore, a high voltage is applied between the electrodes. Also, no voltage leak or discharge occurs. As a result, a strong electric field can be generated between the electrodes, so that the performance of collecting particles in the air can be significantly improved. In addition, there is no concern that ozone will be generated due to discharge between the electrodes or that a fire will occur, and the collection performance will be reduced because the collected particles will not reduce the charge even if the electrodes are contaminated. There are few things.

[Brief description of drawings]

FIG. 1 is a sectional view of an air cleaning device according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view of an electrode used in the air cleaning device according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a peripheral portion of an electrode used in the air cleaning device according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing a voltage application state of electrodes used in the air cleaning apparatus according to the first embodiment of the present invention.

FIG. 5 is a sectional view of an air cleaning device according to a second embodiment of the present invention.

FIG. 6 is a circuit diagram showing a voltage application state of electrodes used in an air cleaning apparatus according to a second embodiment of the present invention.

FIG. 7 is a perspective view of an electrode and a filter medium used in the air cleaning device according to the second embodiment of the present invention.

FIG. 8 is a circuit diagram showing a voltage application state of electrodes used in the air cleaning apparatus according to the second embodiment of the present invention.

[Explanation of symbols]

 2 Filter material 10 Electrode 12 Insulating material

Claims (3)

[Claims] 1. An air purifying apparatus, wherein air in the air is passed between the electrodes 10 to which a high voltage is applied by a blowing means to attract and collect particles in the air toward the electrode 10 side. An air purifier in which the surface of is completely covered with an insulating substance 12. 2. The air cleaning apparatus according to claim 1, wherein the filter medium 2 is interposed between the plurality of electrodes 10 covered with the insulating substance 12, and the particles are collected by the filter medium 2. 3. The electrode 10 is formed in a mesh shape or a plate shape,
The air cleaning apparatus according to claim 1, wherein the surface thereof is covered with an insulating substance 12.