JP2001218828A - Air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cleaner including a plasma generator improving electric discharge efficiency, improving the danger of ignition, and having the excellent easiness for maintenance. SOLUTION: This plasma generator 19 is provided with an insulator 22 covering nearly the whole of a serrated plasma generating electrode 20 formed with lugs 20a alternately on the right and left, and at least the tips of the lugs 20a are exposed without being covered with the insulator 22. Two counter electrodes 21a, 21b and the lugs 20a of the plasma generating electrode 20 face each other at the fixed space distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifier for purifying indoor air, and more particularly, to an air purifier provided with a plasma generator and performing deodorization by plasma.

[0002]

2. Description of the Related Art In recent years, air purifying filters have been improved in performance, and it has become possible to collect dust even invisible fine dust floating in the room. Activated carbon is commonly used. In recent years, however, deodorizing systems using photocatalysts and high-voltage discharge have been increasing in order to achieve higher performance.In particular, the main equipment that realizes functions such as dust collection, deodorization, and generation of negative ions has been 2. Description of the Related Art A high-voltage discharge method using a uniform electric field has been widely used. In particular, a type using plasma is mainly marketed mainly for deodorization.

[0003] In plasma deodorization, when a high-voltage pulse discharge is applied to an electrode having an uneven electric field, extremely reactive molecules or atoms called free radicals are formed between the electrodes.
This is a deodorization method that uses its unstable properties to oxidize and decompose odors.

FIG. 5 is a side sectional view of a conventional air cleaner, and FIG.
Is a perspective view of a conventional plasma generator, FIG. 7 is an electric circuit block diagram of a plasma generator related to a conventional air cleaner,
FIG. 8 is an explanatory diagram showing a corona discharge current by a conventional plasma generator. In the figure, reference numeral 1 denotes a main body of an air purifier, the outer shell of which forms a vortex chamber 2a inside the main body 1, has a rear case 2 having an air outlet 2b on an upper surface, and a suction port 3a on a front surface, The front cover 3 is detachably attached to the rear case 2. Further, a partition frame 4 is provided inside the main body 1 so as to oppose the front cover 3 so as to partition an almost middle portion of the inside of the main body 1, and dust, mold, ticks and the like in the air are provided on the front side of the partition frame 4. A dust collection filter 5 for trapping air is detachably mounted, and a motor 7 for rotating a fan 6 for guiding air to the air passage 2a side of the main body 1 is mounted substantially at the center of the rear surface of the partition frame 4. The fan 6 is fixed to a rotating shaft of the motor 7 by a fixing nut 8.

[0005] 9 is a plasma generator, a plurality of projections 10
a formed on the plasma generating electrode plate 10 and the two opposing electrode plates 11a and 11b.
a is formed so as to be opposed to the two opposing electrode plates 11a and 11b at a fixed spatial distance so as to be alternately left and right, and is attached by fitting the electrode fixing portion 12. These two electrodes 10, 11 are arranged in the air passage 2a of the main body 1 in parallel with the suction air flow, and
It is connected to the high voltage generator 13 via 3a. Further, an activated carbon filter 14 for adsorbing by-products generated by the plasma is provided behind the plasma generator 9. In the upper part of the partition frame 4,
A control board 15 for controlling the operation of the air purifier is provided. Then, as shown in FIG. 7, the commercial power supply (AC 100 V) is directly supplied to the high-voltage
After being converted to DC by the rectifier circuit unit 17,
The voltage is raised to a desired high voltage by the high voltage transformer section 18 and applied to the plasma discharge electrode plate 10. The applied voltage causes a streamer-corona discharge between the opposing electrode plates 11a and 11b to decompose oxygen molecules in the air, in particular, to generate radicals. The generated radicals oxidize and decompose the malodorous components, and the remaining odorous components are removed by passing through the activated carbon 14 and released by the fan 6 from the outlet 2b.

Elements for efficiently generating radicals by plasma include two factors, that is, a spatial distance, a discharge voltage, and a high voltage generation voltage waveform. The clearance must be a certain distance away from the safety aspect, and at that distance,
It is necessary to apply as high a voltage as possible to perform a discharge phenomenon called streamer corona discharge among corona discharges. However, if the DC voltage is increased for home use, it is not preferable to increase the DC voltage for safety, and there is a problem with the space inside the main body, so that the voltage cannot be widened. If the voltage is excessively increased within a specific space distance, spark discharge will occur.

[0007] In order to perform efficient discharge in which radicals are easily generated within a specific space distance, a method of applying a voltage having a pulse waveform is optimal. By making the voltage pulse-like, the rise time from 0 V to a high voltage becomes steep. As a result, the movement of ions between the discharge electrodes is reduced, and only the electrons that collide with molecules to create radicals are efficiently accelerated. Becomes possible. In addition, by using a high pulse voltage, a wide plasma space can be obtained even with the same voltage as a direct current, so that the region where radicals are present is wide and the effect of oxidative decomposition of offensive odor is great.

[0008] As for the shape of the plasma generating electrode plate 10, a wire using wire is seen. However, when a high voltage is applied, the wire becomes hot, and if used for a long time, there is a risk of disconnection. , Can not function. On the other hand, in order to generate corona discharge, the high-voltage generating electrode plate 10 is formed into a needle-like shape, and the plate thickness is reduced to discharge toward the opposing electrode plates 11a and 11b. There is a need.

[0009] The plasma generating electrode plate 10 is
A non-uniform electric field can be formed even in the direction perpendicular to a and 11b. However, in a home air cleaner, a space is required, and the plane is also perpendicular to the air path.
It affects the pressure loss.

[0010]

The air purifier provided with the conventional plasma generator has been configured as described above.
Streamer corona discharge was performed as a plasma generator, and deodorizing performance was obtained. However, since the surface of the plasma generating electrode plate 10 is parallel to the opposing electrode plates 11a and 11b even in the flat plate portion 10b other than the tip of the protrusion 10a, the discharge is slightly generated in the flat plate portion 10b as shown in FIG. Electric current is generated, and the tip 10
The power to a decreases, which is a factor that lowers the discharge efficiency.

Further, since the plasma generating electrode plate 10 is made of the same material except for the protrusions 10a, the plate thickness is small even if spark discharge is generated due to adhesion of dust or maintenance is performed. There were problems such as easy deformation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems.
It is an object of the present invention to provide an air purifier equipped with a plasma generator excellent in the risk of ignition and easy in maintenance.

[0013]

SUMMARY OF THE INVENTION An air purifier according to the present invention has a plurality of opposed electrode plates arranged in parallel along a suction air flow, and a plurality of projections formed between the opposed electrode plates. An air purifier provided with a plasma generating device comprising the above-mentioned plasma generating electrode plate, wherein the plasma generating electrode plate is covered with an insulator except for the tip of the projection.

Further, the insulator is formed of a hard material such as ceramic.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 is a side sectional view of an air purifier showing a first embodiment of the present invention, FIG. 2 is a perspective view of a plasma generator in the first embodiment of the present invention, and FIG. 3 is an enlarged perspective view of a main part of FIG. FIG. 4 is a side view showing a corona discharge current according to the first embodiment of the present invention. The same parts as those of the conventional example described with reference to FIGS.

In FIG. 1 to FIG. 4, reference numeral 19 denotes a plasma generator, which is provided between two counter electrode plates 21a and 21b which are arranged in parallel along a suction air flow, and is provided between the counter electrode plates. The plasma generation electrode plate 20 is formed with the projections 20a alternately formed on the left and right sides. Numeral 22 denotes an insulator made of a hard material such as ceramic which covers almost the entire surface of the plasma generating electrode plate 20 except for the tip of the projection 20a. Accordingly, the flat plate portion 20b is entirely covered with the insulator 22, and only the tip end of the projection 20a is exposed from the insulator 22, and the two opposing electrode plates 21 are exposed.
a and 21b with a certain space distance therebetween.

A commercial power supply (AC 100 V) is connected to the control board 16.
Is supplied directly to the high-voltage generator 13 through a path dedicated to the plasma generator, is converted into a direct current by the rectifier circuit 17, is then boosted to a desired high voltage by the high-voltage transformer 18, and is supplied to the plasma electrode plate 20. Applied. The applied voltage generates a streamer corona discharge between the counter electrode plates 21a and 21b, and decomposes oxygen molecules in the air, in particular, to generate radicals. The generated radicals oxidize and decompose the malodorous components, and the air from which the remaining malodorous components have passed through the activated carbon filter 14 is removed by the fan 6 into the blowout port
It is released from b.

In the streamer corona discharge generated by the uneven electric field, a corona discharge phenomenon toward the opposing electrode plates 21a and 21b can be confirmed while forming triangular prism lines of electric force from the tip of the projection 20a. Similar to the tip of the projection 20a, the flat electrode portion 20b also has the opposite electrode plates 21a,
Since the distance from the electrode 1b is the same and the potential is the same, a small-scale discharge current flows between the electrodes.

However, in the first embodiment, since the flat plate portion 20b of the plasma generating electrode plate 20 is covered with the insulator 22, even if the same potential is generated, the counter electrode plates 21a and 21b are not applied. No current flows. Accordingly, since the discharge is performed only at the projection 20a of the plasma generating electrode 20, the discharge current that has been lost in the conventional flat plate portion 20b also flows into the projection 20a, so that the discharge efficiency in this portion is improved and the deodorizing performance is improved. Can be done.

If the dust is generated and static electricity is generated on the plasma generating electrode plate 20 and the dust adheres to the plasma generating electrode plate 20 and is moist, the dust passes between the flat plate portion 20b and the opposing electrode plates 21a and 21b. Although a current flows and spark discharge causing ignition easily occurs, the occurrence probability can be reduced by covering almost the entire surface of the plasma generating electrode plate 20 with the insulator 22.

Further, even when performing an operation of removing dust adhering to the plasma generating electrode plate 20 by maintenance, a hard material such as ceramic is used for the insulator 22 so that the plasma generating electrode plate 20 at the time of the removing operation is removed. Deformation can be prevented.

As described above, by providing the insulator 22 that covers almost the entirety of the plasma generating electrode plate 20 except for the projections 20a, the discharge efficiency can be improved.
The probability of occurrence of spark discharge that causes ignition can also be reduced. In addition, in terms of maintenance, the concern about deformation of the electrode plate can be eliminated, and maintenance can be easily performed.

In the first embodiment, the protrusion 20
Although a configuration is shown in which the entirety of the plasma generating electrode plate 20 is covered with the insulator 22 except for a, if it is not necessary to obtain an effect other than improvement in discharge efficiency, it is necessary to cover substantially the entire flat plate portion 20b. Instead, a structure in which a part is covered with the insulator 22 may be adopted.

[0024]

As described above, the air purifier according to the present invention has a plurality of opposing electrode plates arranged in parallel along the suction air flow and a plurality of projections formed between the opposing electrode plates. In the air purifier provided with the plasma generating device composed of the plasma generating electrode plate and the plasma generating electrode plate, since the plasma generating electrode plate is covered with the insulator except for the tips of the projections, unnecessary positions for discharge are provided. No extra corona discharge current is generated, and the discharge efficiency can be improved. Further, an effect can be expected also on a reduction in the ignition factor due to the adhesion of dust and the like.

Further, by forming the insulator from a hard material such as ceramics, the plasma generating electrode plate having a small thickness is less likely to be deformed, and maintenance can be facilitated.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an air purifier showing a first embodiment of the present invention.

FIG. 2 is a perspective view of the plasma generator according to Embodiment 1 of the present invention.

FIG. 3 is an enlarged perspective view of a main part of FIG. 2;

FIG. 4 is a side view showing a corona discharge current according to the first embodiment of the present invention.

FIG. 5 is a side sectional view of a conventional air purifier.

FIG. 6 is a perspective view of a conventional plasma generator.

FIG. 7 is a block diagram of an electric circuit of a conventional plasma generator for an air purifier.

FIG. 8 is a side sectional view showing a corona discharge current of a conventional plasma generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main body, 19 plasma generator, 20 plasma generation electrode plate, 20a protrusion, 20b flat plate part, 21a, 2
1b Counter electrode plate, 22 insulator.

Continuation of front page (72) Inventor Yosuke Kushita 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation F-term (reference) 4C080 BB02 CC01 QQ20 4D054 AA11 BB06 BB09 BB12 EA01 EA27

Claims (2)

[Claims] 1. A plasma generating apparatus comprising: a plurality of opposed electrode plates arranged in parallel along a suction air flow; and a plasma generating electrode plate provided between the opposed electrode plates and having a large number of projections formed thereon. The air cleaner according to claim 1, wherein the plasma generating electrode plate is covered with an insulator except for a tip of the projection. 2. The air purifier according to claim 1, wherein said insulator is formed of a hard material such as ceramic.