JPH0636876B2 - Ion-style air purifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an ionic wind type air cleaner which is effectively used as an air cleaner for automobiles, households and the like.

[Conventional technology]

It is conventionally known that when a high voltage is applied between the discharge electrode and a counter electrode arranged so as to face the discharge electrode, corona discharge is generated from the discharge electrode toward the counter electrode, and ionic wind is generated.

That is, the air near the discharge electrodes is ionized by the corona discharge, and the ions move toward the counter electrode due to electrostatic force. In the process of this movement, many neutral molecules are repelled, and the flow of molecules, that is, the wind, is induced. This ion wind can obtain a wind speed of several meters per second, and it is possible to obtain a sufficient air volume depending on the usage. Further, during the corona discharge, dust in the air is also ionized and has a function of collecting this dust on the dust collecting electrode.

Therefore, if this ionic wind can be used, the air blower and the dust collector can be integrated, the use of a blower having a fan and a motor can be eliminated, and the air purifier can be made smaller and lighter. Further, since there is no movable part and the duct can be freely set, when used in an air purifier, the degree of freedom in designing the shape is increased, and a thin object can be easily designed.

Particularly in the case of an air purifier attached to the ceiling of an automobile or the like, a thin thickness is indispensable for the reason that a rear view must be secured.

[Problems to be solved by the invention]

However, the inventors of the present invention have conducted a detailed study and found that in order to reduce the ion wind generation portion, the discharge electrode (metal wire of several tens of μm or the like) and the wall of a duct or the like made of an insulator or the like are formed. It became clear that it was not possible to take a sufficient interval. In such an ion wind generation part, among the ions generated in the vicinity of the discharge electrode, ions having the same polarity as this discharge electrode are pulled to the counter electrode,
On the other hand, ions having the opposite polarity to the ions are absorbed by the discharge electrode and give an electric charge. However, the present inventor has found that when the distance between the discharge electrode and the wall is short, as described above, the ions that should give charges to the discharge electrode move toward the wall (capacitively ground potential). discovered. At this time, since the ions have the same polarity as that of the counter electrode, the ions move in the direction opposite to the counter electrode, that is, in the direction opposite to the ion wind flow.
Therefore, in the vicinity of this wall, the flow of ions will flow not only in the direction of the counter electrode but also in the opposite direction, which will impede the flow of ion wind, resulting in a decrease in the amount of ion wind. However, it became clear that in the worst case, a backflow phenomenon may occur.

[Means for solving problems]

In order to solve the above problems, the present invention is arranged at a predetermined distance on the air inlet side of the discharge electrode so that an intermediate potential between the discharge electrode and the electric field forming electrode is applied. The present invention acts on an ionic wind type air purifier provided with the configured ion repulsion electrode.

[Action]

According to the above means, the ion repulsion electrode repels the ions, which try to move in the opposite direction from the discharge electrode toward the wall, by the electrostatic power and pushes them back in the opposite direction, resulting in the turbulence of the ionic wind near the wall. Can be prevented.

〔Example〕

 FIG. 1 shows the basic configuration of the first embodiment of the present invention.

In FIG. 1, 1 is platinum having a diameter of 10 μm, or
It is a discharge electrode composed of a wire such as tungsten,
A plurality of both ends of the duct 5 are stretched at regular intervals via a spring (not shown) and made of an insulating material such as acryl or ABS resin so that there is no slack. 2 is
It is a counter electrode composed of a metal plate such as aluminum or stainless steel with a thickness of about 0.5 to 1 mm, and is composed of resin or the like at both ends (not shown) so that it is parallel to the air flow and at regular intervals. It is housed in the holder and is connected to the duct 5
It is installed inside. Reference numeral 3 is a dust collecting electrode formed of a metal plate similar to the counter electrode 2, and is housed in the holder in the same manner as the counter electrode so as to be at an intermediate position of the counter electrode. At this time, the air upstream end 3a of the dust collecting electrode 3 is installed downstream from the air upstream end 2a of the counter electrode. Further, the discharge electrode 1 is arranged on the air upstream side of the counter electrode 2 so as to come to the intermediate position of each counter electrode plate 2. The counter electrode 2 and the dust collecting electrode 3 form the electric field forming electrode of the present invention. Four
Is made of a metal such as stainless steel or aluminum, is embedded in the wall surface of the duct 5 made of an insulating material such as the resin, and is arranged such that the inner surface of the duct and the inner surface of the duct are flush with each other. It is a frame-shaped ion repulsion electrode fixed to the duct 5 with an adhesive or the like.

The ion repulsion electrode 4 is installed at a constant interval on the air upstream side of the discharge electrode 1.

A high voltage power source 6 has a negative electrode side connected to the dust collecting electrode 3 and a positive electrode side connected to the discharge electrode 1. On the other hand, a potential having a positive polarity and lower than the potential of the discharge electrode 1 is applied to the ion repulsion electrode 4. The counter electrode 2 is grounded.

The ion repulsion electrode 4, the discharge electrode 1, the counter electrode 2, and the dust collection electrode 3 configured as described above are sequentially arranged in the resin case 5 from the air intake port 5a toward the air outlet port 5b. FIG. 2 shows an automobile air purifier using the configuration of the first embodiment.

This air purifier has a flat resin case 5 as shown in the figure.
An ion wind generating part A consisting of a discharge electrode 1 and an ion repelling electrode 4, a dust collecting part B consisting of a counter electrode 2 and a dust collecting electrode 3 are arranged in the same manner as in the above embodiment, and the end of the case 5 is placed. Part 5
The structure is such that the high voltage power source 6 integrated with the case is housed in c, and is configured to be attached to the ceiling of the automobile. The air intake port 5a and the air outlet port 5b are
Each is provided with a grill, 7 and 8 so that foreign matter and fingers cannot enter. The counter electrode 2 and the dust collecting electrode 3
Is detachably attached.

The electrode 4 for ion repulsion in the ion wind generator A is
Is the same as the distance between the discharge electrode 1 and the counter electrode 2, or
A distance greater than that is maintained between the discharge electrode 1. Further, the voltage applied to the electrode 4 for ion repulsion is
An intermediate voltage between the discharge electrode 1 and the counter electrode 2 is applied.

Next, the operation of the first embodiment will be described. In FIGS. 1 and 2, a power source 6 is provided between the discharge electrode 1 and the counter electrode 2.
When a high voltage (several Kv to several tens of Kv) is applied at, a non-uniform electric field is formed between the two electrodes due to the difference in electrode shape (φ60μ and t0.5 mm), and the shape of the discharge electrode 1 of 60μ is sharp. The electric field concentrates on the surroundings and corona discharge occurs.
Due to this corona discharge, both positive and negative polar ions are generated, but most of the negative ions having the opposite polarity to the discharge electrode 1 are absorbed by the discharge electrode 1, and only the positive ions having the same polarity are generated in the counter electrode 2. Will be attracted to. The positive ions collide with a large number of neutral gas molecules in the process of being attracted to the counter electrode 2 and give kinetic energy to these neutral gas molecules to drive them, whereby the positive ions and the neutral gas molecules are driven. Both generate wind towards the counter electrode 2.

Further, since dust in the air is charged by the ions generated by the corona discharge, as shown in FIGS. 1 and 2, the dust collecting electrode 3 is installed at the intermediate position of the counter electrode 2, By applying a negative potential to this, an electric field is formed between it and the counter electrode 2 which is grounded. At this time,
The dust is positively charged by the positive ions in the ion wind generator. Therefore, although some of the dust adheres to the counter electrode 2, most of the dust is mostly collected on the dust collecting electrode 3 by the electric field formed by the counter electrode 2 and the dust collecting electrode 3.

Therefore, the dirty air in the vehicle compartment is sucked in through the inlet grill 7 as shown by the arrow D in FIG. 8
It is blown out into the passenger compartment through.

Generally, in order to efficiently generate ionic wind, the distance between the discharge electrode 1 and the counter electrode 2 should be as large as possible,
It is necessary to cause generated ions to collide with as many neutral gas molecules as possible while reaching the counter electrode by giving a high potential difference. Therefore, in the thin ion wind generator, the distance between the discharge electrode 1 and the counter electrode 2 is shorter than the distance between the discharge electrode 1 and the wall. In the case of this embodiment, assuming that the counter electrode 2 is grounded and the wall (capacitance is the same as grounded) has the same potential, the ions generated by the corona discharge near the discharge electrode 1 are: In order to move to a place with a large potential difference as close as possible, negative ions move in that direction because there is a place with a high positive potential (discharge electrode 1) in the immediate vicinity. Not only the counter electrode 2, but also the positive ions generated especially around the discharge electrode 1 near the wall move toward the wall, disturb the flow near the wall, and further change the potential of the wall. , Tries to affect the corona discharge at the discharge electrode near the wall, but the ion repulsion electrode 4
Are of the same polarity as the positive ions, the ions that try to face the wall are repelled, and most of them move toward the counter electrode 2, and the generation of ionic wind is not hindered, and the ionic wind generation efficiency is improved. Is improved.

The ion repulsion electrode 4 may be on the upstream side of the discharge electrode 1, but is preferably 10 mm to several tens of mm on the upstream side. The potential of the ion repulsion electrode 4 may be lower than that of the discharge electrode 1, but if it is too low, the amount of ozone generated may increase. 3 to 6 show
It is an example of the result of having investigated the characteristic when changing the electric potential using the said ion repulsion electrode 4. In FIG. 1, the distance between the discharge electrode 1 and the tip 2a of the counter electrode 2 is set to 20 mm, and the distance to the tip 3a of the dust collecting electrode 3 is set to 30 mm, and the pitch of the discharge electrode 1 is 10 mm. Has a pitch of 10 mm, a dust collecting electrode is installed at an intermediate position of the counter electrode 2, and the ion repulsion electrode 4 is a metal band having a width of 8 mm, and the discharge electrode 1 and the discharge electrode of the ion repulsion electrode 4 are The distance to the end on the 1st side is set to 10 mm. The discharge electrode 10 has a wire diameter of 60 μ, and the opposed dust collecting electrode has a plate thickness of 0.5 mm. Further, FIGS. 3 and 4 are obtained by examining the potential distribution in the cross section of FIG. 3, and the lines in the figures represent equipotential lines. Fig. 3 shows 14K on the discharge electrode 1.
v, the counter electrode 2 is grounded, and the dust collecting electrode 3 is -2.5K.
v, the ion repulsion electrode 4 is grounded. FIG. 4 is different from FIG. 3 only in that the potential of the ion repulsion electrode 4 is set to 10 Kv. In FIGS. 3 and 4, the equipotential lines around the discharge electrode 1 are dense,
The electric field is concentrated at this place, and corona discharge is occurring. Comparing FIGS. 3 and 4, here, the electric field concentration is greater in FIG. 3 and the corona discharge becomes more active,
More ions are being generated. However, among the generated ions, the negative ions are absorbed by the discharge electrode 1, but the positive ions proceed to the periphery of the discharge electrode 1 in the direction perpendicular to the equipotential lines in the figure, and further the equipotential. The more you go, the denser the line (the steepest slope of the potential). Therefore, when the ion repulsion electrode 4 of FIG. 3 is grounded, a large amount of positive ions advance not only in the direction of the counter electrode 2 but also in the direction of the wall (or the ion repulsion electrode) especially from the discharge electrode near the wall. I know you can go by. On the other hand, in the case where a potential of 14 Kv is applied to the ion repulsion electrode 4 in FIG. 4, corona discharge is slightly reduced, but the dense equipotential line is only in the direction of the counter electrode 2, and this equipotential line is also present. The line is also perpendicular to the direction of air flow, and it can be seen that ionic wind is efficiently generated. Considering here the case where the ion repulsion electrode 4 is not provided, at first, since the wall is close to the ground, the third
Depending on the surface condition of the duct 5, which is an insulator, which shows the potential distribution as shown in the figure, it is conceivable that charges may accumulate and approach the direction shown in FIG. 4, but if the duct is used for a long time, If the inner surface of 5 becomes dirty, a leak from the bath surface may occur, and sometimes abnormal discharge may occur. Therefore, the provision of the ion repulsion electrode 4 is useful not only for preventing backflow of ions but also for stabilizing and generating corona discharge for a long time.

Next, the result of examining the ozone concentration when the voltage applied to the ion repulsion electrode 4 is changed will be described. A voltage of + V ₁ is applied to the discharge electrode 1, the counter electrode 2 is grounded, a voltage of −V ₃ is applied to the dust collecting electrode, and + V ₁ is applied to the ion repulsion electrode.
By applying a _second voltage, as generated ion wind velocity v is constant, which controls the V _1, V _2, to the difference between the voltage of the V ₁ and V _2, was examined ozone concentration generated But,
It is FIG. As shown in the figure, even if the wind speed v is the same, when the difference between the voltage of the ion repulsion electrode 4 and the voltage of the discharge electrode 1 is 5 Kv or less, the amount of ozone generated is constant, but the voltage difference is 0.
When it is above Kv, the ozone concentration increases. However, if the difference between V ₁ and V ₂ is as large as possible, corona discharge in the vicinity of the wall of the discharge electrode 1 becomes more vigorous, and the same wind speed can be obtained at a lower voltage (V ₁ ). From these things, the voltage applied to the ion repulsion electrode 4 is
About 4 Kv lower than the voltage applied to is appropriate.

Further, in the present embodiment, a metal plate-like material is embedded in the inner surface of the duct 5 to form the ion repulsion electrode 4, but as the ion repulsion electrode 4, a thin metal film (10 aluminum foils) is used.
(about μ) is attached to the inner surface of the duct 5 on the upstream side of the discharge electrode 1 (the side opposite to the counter electrode 2 with respect to the discharge electrode 1) with a certain distance from the discharge electrode 1 by adhesion or the like. Further, as a method of exhibiting the same effect, a conductive paint using silver or carbon may be applied to the same position. The function and effect are the same as in the first embodiment.

Next, a second embodiment of the present invention will be shown. In this embodiment, instead of burying the ion repulsion electrode 4 in the inner surface of the Dagto 5, as shown in FIG. 7, the ion repulsion electrode 4 is placed slightly (about several mm or more) away from the inner surface of the duct 5. , Thickness several mm, width several mm
The ion repulsion electrode 4 is made of a plate of aluminum, stainless steel or the like having a size of several tens of millimeters. The ion-repellent electrode 4 is not limited to a plate-shaped metal, and may be a metal rod or a pipe-shaped member that does not block the flow of air, and can be any electrically conductive member. Anything is fine. Other configurations and structures are the same as those in the first embodiment.

FIG. 7 shows a third embodiment of the present invention. Generally, in an air purifier, not only dust collection but also odor in the air may have to be removed. As the deodorizing device used at this time, activated carbon is often used,
The same can be applied to the case of ionic wind. However, as a characteristic of the ion wind, the wind pressure is small, and if activated carbon is installed in the downstream portion, the pressure loss will cause the ion wind velocity to drop extremely. Therefore, even if the duct at the downstream side of the ionic wind is widened, it is less effective than the ionic wind because the wind has a strong straight traveling property. Therefore, as in the present embodiment, it is intended to deodorize the air by installing activated carbon on the inlet side of the ionic wind duct 5. In FIG. 7, activated carbon is attached to the inner surface of a filter 9 made of aluminum or the like and formed in a honeycomb shape. On the other hand, the suction port 5a side of the duct 5 is expanded in a trumpet shape on the upstream side from the ion repulsion electrode 4, and a filter 9 is arranged at the inlet end. The total cross-sectional area of the air passage of the filter 9 is configured to be larger than the cross-sectional area of the straight portion on the downstream side of the duct 5. Therefore, by installing the activated carbon at the ion wind inlet, the air can be introduced from almost all directions, so that a large pressure loss with respect to the ion wind does not occur and a large amount of activated carbon can be installed. At this time, since activated carbon has some conductivity,
By grounding it, it can also be used as a guard electrode against high voltage. Furthermore, this filter 9 is used as a pre-filter to remove relatively large dust such as lint,
It is also possible to prevent obstruction in the ion wind generating part.

Next, in any of the above examples, a negative potential was applied to the dust collecting electrode 3, but a positive potential is applied to the dust collecting electrode 3 unless an abnormal discharge is generated between the dust collecting electrode 3 and the counter electrode 2. You may give it.
That is, it suffices if there is an electric field between the counter electrode 2 and the dust collecting electrode 3 to the extent that no abnormal discharge occurs.

Further, in the above-mentioned embodiments, the discharge current is set to a high voltage of + because the positive ions are moved to the counter electrode and the movement of the positive ions causes wind. Therefore, the polarity of the discharge electrode 1 may be negative or ground if the voltage setting of the discharge electrode and the counter electrode is such that only positive ions move toward the counter electrode. For example, when the discharge electrode 1 is grounded, the counter electrode 2
Must be applied with a negative voltage, and a voltage capable of forming an electric field necessary for dust collection can be applied to the dust collection electrode 3 unless abnormal discharge occurs. Further, at this time, the ion repulsion electrode 9
As in the first embodiment, a voltage slightly lower than that of the discharge electrode 1 (in this case, a negative voltage) may be applied to the battery.

〔The invention's effect〕

As described above, according to the present invention, by providing the ion repulsion electrode to which a voltage is applied between the discharge electrode and the electric field forming electrode, it is possible to prevent the turbulence of the ionic wind near the case wall forming the ventilation passage. Therefore, a large wind velocity can be obtained even when the distance between the discharge electrode and the inner wall of the case is small, and as a result, the ion wind blower can be thinned.

[Brief description of drawings]

FIG. 1 is a schematic view showing the basic structure of an ion wind type air purifier according to the first embodiment of the present invention, and FIG. 2 is an external view of a ceiling-mounted air purifier for automobiles, FIGS. FIG. 5 is a distribution diagram showing potential distributions formed with and without the ion repulsion electrode 4, and FIG. 5 shows the voltage of the ion repulsion electrode 4,
FIG. 6 is a characteristic diagram showing a change in ozone concentration with respect to a change in the difference with the voltage of the discharge electrode, FIG. 6 is a schematic sectional view showing a second embodiment of the present invention, and FIG. 7 is a third embodiment of the present invention. 3 is a schematic cross-sectional view of an example. FIG. 1 ... Discharge electrode, 2 ... Counter electrode, 3 ... Dust collection electrode, 4
…… Ion repulsion electrode, 5 …… Case, 5a …… Air inlet, 5b …… Air outlet, 6 …… High voltage power supply.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masaru Hattori, 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute (72) Inventor Teiichi Nabeta, 1-1, Showa-cho, Kariya city, Aichi Japan Denso Co., Ltd. (56) Reference JP-A 61-64355 (JP, A) JP-A 60-187357 (JP, A) JP-A 60-187358 (JP, A) JP-A 61-25049 ( JP, A) JP 62-140657 (JP, A) JP 60-132661 (JP, A)

Claims (7)

[Claims] 1. A discharge electrode which has an air inlet and an air outlet and which is provided in a case forming a ventilation path and induces corona discharge, and a discharge electrode which is provided in the case and faces the discharge electrode. In the ion-air type air cleaner provided with the electric field forming electrode and the high voltage power supply, the discharge electrode and the electric field forming electrode are arranged at a predetermined distance on the air inlet side of the discharge electrode. An ion wind type air purifier comprising an ion repulsion electrode configured to be applied with an intermediate potential. 2. The ionic wind type air purifier according to claim 1, wherein the discharge electrode is made of a thin metal wire, and the electric field forming electrode is made of a flat thin plate metal. 3. The electric field forming electrode is composed mainly of a counter electrode for forming an electric field between the electric field forming electrode and the discharge electrode, and a dust collecting electrode for mainly adsorbing and collecting ionized dust particles. The ion wind type air purifier according to claim 1 or 2, which is characterized. 4. The discharge electrode is connected to the positive electrode of the high voltage power source, the counter electrode is grounded, the dust collecting electrode is connected to the negative electrode of the high voltage power source, and the ion repulsion electrode is connected to the high voltage source. The ion wind type air purifier according to claim 3, wherein the ion wind type air cleaner is connected to the positive electrode of the voltage power source and an electrode having a lower potential than the discharge electrode. 5. The discharge electrode is grounded, the counter electrode is connected to a negative electrode of the high voltage power source, the dust collecting electrode is also connected to a negative electrode of the high voltage power source, and the ion repulsion electrode is
The ion wind type air purifier according to claim 4, wherein the high voltage power source is connected to the negative electrode and an electrode having a potential higher than that of the counter electrode. 6. The ion repulsion electrode is a strip-shaped conductive member, and the ion repulsion electrode according to claim 1 or 5.
An ionic wind type air purifier according to any one of paragraphs. 7. The air intake port of the case has a shape in which the cross-sectional area of the passage widens toward the upstream end of the air, and the intake port portion is provided with a deodorant. The ionic wind type air purifier according to any one of items 1 and 6.