JPS61212346A - Air purifier - Google Patents

Abstract

PURPOSE:To prevent the abnormal electric discharge due to a dust layer accumulated on a dust collection plate in an air purifier performing the corona discharge by making the dust collection electrode a water retention electrode and making the surface of this electrode wet. CONSTITUTION:The dust collection electrodes 1 consist of the electrodes which are made of a sintered material of Al body and have the water retention characteristics and the counter electrodes 2 are manufactured of a simple substance of Al plate. The ionizing wires 3 made of W or the like are erected nearly on the extension lines of each counter electrodes 2. When the corona discharge is caused between the ionizing wires 3 and the dust collection electrodes 1, the dust is collected on the dust collection electrodes 1. In this case, even when the amount of dust to be collected is increased and it is made to a layer-shape, the dust layer is made wet by the water retention characteristics of the dust collection electrodes 1 and is not made to the insulation. Therefore the electrostatic charge is not caused in this dust layer and the generation of the abnormal electric charge can be prevented.

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to an air purifier that uses corona discharge, and particularly to an air purifier that prevents abnormal discharge due to a layer of dust accumulated on a dust collecting electrode plate. It is related.

(Prior Art) A conventional air cleaner that uses corona discharge will be described by taking as an example an air cleaner that also uses the corona discharge as a blowing means. This air purifier has a unit frame installed inside a casing equipped with an air inlet and an air outlet, and a plurality of dust collection electrode plates made of aluminum plates placed in the unit frame with a required gap to form an air flow path. are arranged side by side, and an ionization line is installed at a position extending from the approximate center of each gap and at a required distance from a line connecting the tip edges of each dust collecting electrode plate.

Then, when a required high voltage is applied between the ionizing wire and the collecting electrode plate, with the ionizing wire being depolar and the collecting electrode plate being unipolar, a positive corona discharge will occur between the ionizing wire and the collecting electrode plate. When the frequently encountered cations are attracted to the dust collection electrode plate side and move, the kinetic energy is given to the air and the viscosity of the air generates an air flow from the ionization line side to the gap side. do. With the generation of this air flow, dust in the air is charged with positive ions, which are collected on the dust collection electrode plate and have an air purifying effect. In this way, the dust collecting electrode plate functions not only as a discharge counter electrode but also as a dust collecting plate.

(Problem to be solved by the invention) By the way, when the dust accumulated on the dust collecting electrode plate forms a layer and dries, this becomes a resistor layer, and its resistance value becomes 1010Ωα.
If it exceeds a certain level, it becomes insulating.

For this reason, the surface of the dust layer is charged with electric charge, and a strong electric field is applied to this dust layer, and the average electric field strength becomes 103 V/α or more. The breakdown voltage of the dust layer is around 3 x 10'V/I:11, so there is local resistance in the dust layer.

If there is a small point, dielectric breakdown occurs at that point, charge flows to the electrode plate in an avalanche phenomenon, and abnormal discharge occurs. When an abnormal discharge occurs, in the case of a + corona discharge from an ionizing line, a corona opposite to this is generated, and in the case of a corona discharge from an ionizing line, a + corona is generated. This phenomenon is called back corona, and when it occurs, the amount of ozone generated increases significantly, and the safety of equipment is compromised by damaging electrodes and power supplies. In the case of an air cleaner that also uses corona discharge as an air generating means, as described as a conventional example, the required discharge voltage is high and a high electric field is applied, so the amount of ozone generated is particularly large. For this reason, in such air cleaners, in order to prevent abnormal discharge, measures have been taken to round off the corner portions of the end faces of the dust collection electrodes where abnormal discharge is particularly likely to occur. However, there have been various problems such as increased processing costs and increased equipment costs.

The purpose of the present invention was to solve the problems of conventional air purifiers, and to prevent abnormal discharge caused by the dust layer deposited on the collecting ay electrode, and to prevent corona discharge from occurring by blowing means. As for the air purifier that I used, it's a collection! I
It is an object of the present invention to provide an air cleaner in which rounding of the end face corners of electrodes can be omitted.

(Means for Solving the Problems) In order to achieve the above object, the air purifier according to the present invention includes a dust collecting electrode on one end edge side in which an air flow path is formed.
In an air purifier provided with an ionizing electrode serving as a counter electrode for corona discharge, the dust collecting electrode is a water-retaining electrode and the surface of the electrode is moist.

(Function) Since the collecting gIN electrode is used as a water-retaining electrode and its surface is wet, even if dust accumulates on the surface of the collecting electrode and forms a layer, it does not become insulating and back corona does not occur. is prevented. Therefore, there is no increase in the amount of ozone generated due to this back corona, and there is no damage to equipment due to abnormal discharge. Furthermore, even in air purifiers that use corona discharge as a drafting means, the corners of the tip surface of the 1!1 electrode are rounded to the extent that abnormal discharge does not occur due to retained water. It is not necessary to perform special rounding processing.

(First Embodiment) A first embodiment of the present invention will be described below based on FIGS. 1 and 2.

First, to explain the configuration, a plurality of dust collecting electrodes 1 and corresponding electrodes 2 are arranged opposite to each other alternately with appropriate gap lengths to form air flow paths within a frame such as a unit frame (not shown).

As shown in FIG. 2, the precipitator 1i1 is made of a sintered aluminum body 1b having a diameter of about 0.05 mm, and has water-retentive properties. Further, the corresponding electrode 2 is made of a single aluminum plate. Compatible electrode 2 is Shu! ! ! ! The length in the vertical direction shown in the figure is shorter than that of the electrode 1 by an appropriate length, and the tip surface 2a of each corresponding electrode 2 is formed with an appropriate length of the gap shorter than the line connecting the tip surface 1a of each dust collection electrode 1. It is located inside. Ionization lines (ionization electrodes) 3 are installed in the gaps where the tip surfaces 2a of each of the corresponding electrodes 2 enter and approximately on the extension lines of the corresponding electrodes 2, respectively. As the ionization wire 3, a thin tungsten wire or the like is used.

The manner in which voltage is applied to each electrode 1.2.3 by the power source E is shown in the collection p! Taking electrode 1 as a reference, voltages of different polarities are applied to the ionization line 3 and the corresponding electrode 2, and the voltage values are as shown in Collection I!
l! The voltage value between the dust collection electrode 1 and the counter electrode 2 is approximately 1/2 of the voltage value between the electrode 1 and the ionization line 3. The corresponding electrode 2 is I! This is intended to more efficiently capture dust in the air that has not been captured by the dust electrode 1, and is provided as an auxiliary electrode for dust collection. A forced ventilation means 4 such as a fan is disposed on the side where the ionized wire 3 is installed at a position outside the arrangement portion of each of the electrodes 1.2.3.

Next, the action will be explained.

When a required high voltage is applied between the ionization wire 3 and the dust collection electrode plate 1, with the ionization wire 3 side being unipolar and the dust collection electrode plate 1 side being depolar, the ionization wire 3 and the dust collection electrode plate 1 are During this period, a corona discharge occurs. Due to this corona discharge, the dust in the air passing through the gap serving as the air flow path is charged to negative ions by the forced ventilation means, and the dust is collected on the dust collecting electrode plate 1, thereby performing an air purifying action. At this time, even if the accumulated dust collection scratches increase with the passage of time and use and become layered, the dust layer becomes moist due to the water retention of the collecting electrode 1 and does not become insulating. Therefore, this dust layer is not charged and no abnormal discharge occurs. Therefore, the generation of back corona is prevented, and an increase in the amount of ozone generated due to this back corona is suppressed.

The corresponding electrode 2 roughly and efficiently captures the dust in the air that was not captured by the dust collecting electrode 1, but since the main action of dust collection is performed in the dust collecting electrode 1, the dust The amount of deposition is small compared to the dust collecting electrode 1.

The following table shows the actual measured values of ozone borrowing that occur in general offices over time of use. The table also shows the amount of ozone generated by the conventional example for comparison.

As shown in the same table, the amount of ozone generated increases with the passage of time in the conventional example, but there is almost no increase in the amount of ozone generated in the case of the one according to the present invention.

Note that the water retention period of the dust collection electrode 1 that can prevent abnormal discharge continues for approximately one month. The dust collecting electrode 1, etc., is properly cleaned at each use period to remove accumulated dust, but since this period is approximately one month, water retention to the dust collecting electrode 1 can be replenished at the same time as this cleaning period. .

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention. In this embodiment, the forced ventilation means is omitted and corona discharge is also utilized as the wind generating means.

In FIG. 3, members or parts that are the same as or equivalent to those in FIGS. 1 and 2 are designated by the same reference numerals and redundant explanations will be omitted.

To explain the structure, in this embodiment, the ionization line 3 is installed at a position outside the gap and separated by an appropriate distance from the line connecting the tip surfaces 1a of each dust collection electrode 1.

Further, the voltage value of the voltage E used is higher than that of the first embodiment. The structure of the other electrode portions is substantially the same as that of the first embodiment.

To explain the operation, when a required high voltage is applied from the power source E with the ionization J11 side set as unipolar and the dust collection electrode 1 side set as ten polarity, one corona discharge occurs between the ionization wire 3 and the dust collection electrode 1. When a large amount of anions are attracted to the dust collection electrode 1 side by this corona discharge and move, their kinetic energy is given to the air, and the viscosity of the air causes a wind raising effect in the direction from the ionization 3 side to the gap side. occurs. Along with this wind raising action, the dust in the air is charged with negative ions, which are collected on the dust collection electrode or the like in the same manner as described above, thereby producing an air purifying action. The function of preventing abnormal discharge due to the water retention property of the dust collecting electrode 1 is almost the same as that of the first embodiment.

However, in this embodiment, the corner portion of the tip surface 1a of the dust collecting electrode 1 faces the ionization line 3, and the radiation R voltage is higher than that of the first embodiment. Abnormal discharge is likely to occur at the corners.

but#! Since the dust electrode 1 is made of a sintered material made of a thin aluminum body 1b, the corners are naturally rounded, and the rounding effect due to the surface tension of water retention is effective in preventing the occurrence of abnormal discharge. is prevented.

Note that the water-retentive electrode is not limited to the case where it is manufactured using the sintered material described above, but can also be manufactured in the following manner.

That is, it can also be made from a paper material in which lithium chloride and carbon fiber are mixed. Lithium chloride absorbs water and has water retention properties, and carbon IJItH contributes to conductivity.

Furthermore, simply applying lithium chloride to the surface of a metal plate can provide a water-retentive electrode due to its water-absorbing properties.

Furthermore, water-retaining electrodes can be made from gypsum mixed with carbon. Since gypsum contains water of crystallization, it can retain water.

Further, the mode of applying the voltage between the ionization line 1i13 and the Ti electrode 1 etc. is not limited to the above-mentioned mode of application, but the ionization line 3 side may be fertile, or an alternating current voltage may be used. . At this time, the only difference is the corona discharge and the charging polarity of the ions, and the dust collection effect and the direction of air raising by the air raising means are the same as described above.

(Effects of the Invention) As detailed above, according to the present invention, the dust collecting electrode is a water-retentive electrode and the surface of the electrode is wet, so that dust accumulates on the surface of the collecting electrode and forms a layer. Also, since it does not take on insulating properties, back corona generation is prevented. Therefore, there is no increase in the amount of ozone generated due to this back corona, and there is no damage to equipment due to abnormal discharge. It also applies to air purifiers that use corona discharge as a means of generating wind! Since the corner portion of the tip face of the lN pole is rounded to such an extent that abnormal discharge does not occur due to retained water, this effect provides the effect that it is not necessary to perform special rounding on this corner portion. In addition, water-retentive electrodes,
According to the embodiment made of a sintered material of a small-diameter metal body, in addition to the above-mentioned common effects, the following effects can be obtained. In other words, since the end face corners of the dust collecting electrode are rounded by the small diameter metal body, there is no need for secondary processing for rounding.
The occurrence of abnormal discharge is further prevented, thereby preventing an increase in the amount of ozone and damage to equipment.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing a first embodiment of the air cleaner according to the present invention, FIG. 2 is a partially enlarged plan view of a dust collection electrode in the first embodiment, and FIG. FIG. 2 is a schematic plan view showing a second embodiment. 1... Dust collecting electrode, 1b... Thin diameter metal body, 2...
Corresponding electrode, 3...Ionization wire (ionization electrode), 4...Forced ventilation means, E...Power source. Japan Electric Co., Ltd.

Claims (1)

[Claims] 1. An air purifier in which an ionizing electrode serving as a counter electrode for corona discharge is disposed on one end edge of a dust collecting electrode in which an air flow path is formed, wherein the dust collecting electrode is used as a water retaining electrode. An air purifier characterized by having a moist electrode surface. 2. The air cleaner according to claim 1, wherein the water-retaining electrode is made of a sintered material of a small diameter metal body. 3. The water-retaining electrode is made of a paper material containing lithium chloride and carbon fiber.
Air purifier as described in section.