JP2002346376A - Plasma reactor and air cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance processing efficiency by lessening the useless gap between each of a plurality of streamer discharge regions (S), in a plasma reactor which performs gas treatment by the streamer discharge to produce low temperature plasma. SOLUTION: Among a first electrode (21) and a second electrode which are disposed to face each other, its end of the electrodes (21a) is arranged in a plurality of lines to the first electrode (21). The gap between each of a plurality of the discharged region (S) formed for each of the end of electrode (21a) is lessened by arranging the end of electrodes (21a) in each of the neighboring array (L1, L2, L3, etc.), so that they are shifted from the rectangular line of (C1, C2) to each of the array (L1, L2, L3, etc.).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma reactor for generating a low-temperature plasma by streamer discharge to perform gas treatment such as air purification, and an air purification apparatus using the plasma reactor. In the discharge space efficiently.

[0002]

2. Description of the Related Art Conventionally, a plasma reactor using low-temperature plasma has been detoxified or deodorized by decomposing harmful components and odor components contained in, for example, air and exhaust gas by the action of active species generated by electric discharge. It is used for air purification equipment and gas treatment equipment. For example, Japanese Patent Application Laid-Open No. 8-1552
No. 49 discloses a gas processing apparatus in which a plurality of needle electrodes as discharge electrodes are arranged at right angles to a plane electrode as a counter electrode, and are arranged vertically and horizontally. In this gas processing apparatus, streamer discharge is generated in a space between a discharge electrode and a counter electrode to generate low-temperature plasma, and a gas to be processed is introduced into the discharge space to perform gas processing.

When a streamer discharge occurs in this configuration, a discharge occurs in a columnar region connected to each needle electrode in a discharge space between each needle electrode and the plane electrode. The discharge region may be a conical region that spreads in a flare from each needle electrode toward the surface electrode, depending on the shape of the needle electrode and the setting of the applied voltage.

[0004]

In the apparatus described in the above publication, a plurality of needle electrodes are arranged vertically and horizontally and arranged in a lattice. However, if the needle electrodes are arranged in this way, the lattice shape is a set of squares. However, since the discharge region has a circular cross section, a gap is formed between the discharge regions. Then, since low-temperature plasma is hardly generated in the gap, a useless space exists in the discharge space between the two electrodes. The larger the gap, the lower the processing efficiency.

[0005] The present invention has been made in view of such problems, and an object of the present invention is to provide a plasma reactor for performing low-temperature plasma by streamer discharge to perform gas processing and the like, and to provide a plurality of plasma reactors. The purpose is to reduce the useless gap between the discharge regions to increase the processing efficiency.

[0006]

According to the present invention, there is provided a needle electrode (21a).
By devising an arrangement such as a plurality of discharge areas formed continuously with each needle electrode (21a) etc. in the discharge space (D)
The gap between (S) can be reduced.

More specifically, a first solution taken by the present invention is to discharge a first electrode (21) and a second electrode (22), which are arranged to face each other, and discharge both electrodes (21, 22). Power supply means (24) connected to apply a voltage;
(21) has a plurality of electrode ends (21a) opposed to the second electrode (22), and both electrodes (21, 22) are arranged in the flow space of the fluid to be treated, and both electrodes (21, 22) It is premised on a plasma reactor (20) for treating a fluid to be treated by a streamer discharge generated between them.

In the plasma reactor (20), the electrode ends (21a) are arranged in a plurality of rows, and each row (L1,
L2, L3 ...) electrode ends (21a) are adjacent rows (L1, L2, L3 ...
・) Is located at a position deviated (displaced) from the orthogonal direction (on the orthogonal lines (C1, C2)) of each row (L1, L2, L3 ...) with respect to the electrode end (21a) of It is characterized by.

In the first solution, the first electrode
When a discharge voltage is applied to the (21) and the second electrode (22) from the power supply means (24), a streamer discharge occurs between the two electrodes (21, 22). The streamer discharge consists of a first electrode (21) and a second electrode (2
The continuous micro arc between 2) forms a plasma column with light emission, and this streamer discharge causes various active species (ozone, hydroxy radical, excited oxygen molecule, excited nitrogen molecule, excited water molecule, etc.). Is generated. The electrodes (21, 2) where low-temperature plasma is generated in this way
2) Since the fluid to be processed flows in the space between them, the fluid to be processed is processed under the action of these active species.

Particularly, in the first solution, the electrode ends (21a) are arranged in a plurality of rows, and each of the adjacent rows (L
1, L2, L3 ...) are arranged such that the electrode ends (21a) are shifted from the lines (C1, C2) orthogonal to the respective rows (L1, L2, L3 ...). (L1, L2, L3 ...) electrode end (21a) to the line (C1, C2)
Compared to the case of arranging on top, the adjacent rows (L1, L2, L3
・ ・) Electrode ends (21a) can be brought closer to each other. For this reason, it is possible to cause streamer discharge in a state where the gap between the plurality of discharge regions (S) is reduced.

[0011] The second solution taken by the present invention is:
In the plasma reactor (20) according to the first solution, the electrode end (21a) of the first electrode (21) is connected to each row (L1, L2, L3 ...).
Are arranged at substantially constant intervals within each row (L1, L2, L3 ...)
The pitch dimension (P1) between the electrode ends (21a) in
Pitch dimension between electrode ends (21a) in rows (L1, L2, L3 ...)
(P2) substantially coincides with (P2).

In the second solution, the distance between the adjacent electrode ends (21a) is set such that the distance between the adjacent rows (L1, L2, L3,...) Within each row (L1, L2, L3,. It will be the same in between. For this reason, the intervals between all the electrode ends (21a) are made uniform.Thus, by narrowing the pitch dimensions (P1, P2), the gap between the discharge regions (S) is made to be in a uniformly small state, and the streamer discharge is performed. Can be generated.

[0013] A third solution taken by the present invention is:
The plasma reactor according to the first or second solution (2)
0), the electrode end (21a) of the first electrode (21) is the discharge region (S) generated at the adjacent electrode end (21a).
(22) are arranged so as to substantially contact each other. In addition, "the discharge region (S) is the second electrode
(22) Substantially touching each other on the
It does not mean only the state where (S) is completely in contact, but also includes the state where the discharge areas (S) slightly overlap each other or there is a slight gap between the discharge areas (S). . For example, the overlap or gap of the discharge area (S)
If it is about 20% of the diameter of (S), it can be considered that it is included in a substantially contacting range. Further, the position where the discharge region (S) substantially contacts in the above configuration is not limited to only on the surface of the second electrode, but a slight deviation from this surface is allowed.

In the third solution, the discharge regions (S) are substantially in contact with each other.
A plurality of discharge areas generated between the electrode (21) and the second electrode (22)
Streamer discharge can be generated with the gap between (S) reduced.

Further, a fourth solution taken by the present invention is:
On the same premise as the plasma reactor (20) according to the first solution, the electrode end (21a) of the first electrode (21) is formed in the discharge region (S) generated for the adjacent electrode end (21a). It is characterized in that they are arranged so as to substantially contact each other on the second electrode.

In the fourth solution, the first electrode
A line perpendicular to each row (L1, L2, L3 ...)
(C1, C2) Shifting from above is not limited.
It is not limited that the intervals of (21a) are all constant, but since the respective discharge regions (S) are substantially in contact with each other, a plurality of discharge regions (S) are provided in the same manner as in the third solving means.
With the gap between (S) being further reduced, streamer discharge can be efficiently generated spatially.

Further, a fifth solution taken by the present invention is:
In the plasma reactor (20) according to any one of the first to fourth solutions, the second electrode (22) includes an opening (22a) through which the fluid to be processed passes along the discharge direction. It is characterized by having.

In the fifth solution, the fluid to be processed flows between the first electrode (21) and the second electrode (22).
It passes through the opening (22a) of the second electrode (22) along the discharge direction. Therefore, when the plasma generation region is flared toward the second electrode (22) by specifying the shape of the electrode and the type of applied voltage, the fluid to be processed is located at the most widened portion of the plasma generation region. It passes through the opening (22a) of the second electrode (22) which becomes a (highly active space).

The sixth solution taken by the present invention is:
The plasma reactor (20) according to any one of the first to fifth solving means includes a processing member (23) for processing a fluid to be processed, and the processing member (23) is provided with a first electrode. (twenty one)
And the second electrode (22) or on the downstream side thereof.

In the sixth solution, the processing member
By arranging (23) as described above, the fluid to be processed also passes through the processing member (23) when passing between the first electrode (21) and the second electrode (22). . Therefore, the processing of the fluid to be processed is performed reliably.

[0021] A seventh solution taken by the present invention is:
In the plasma reactor (20) according to the sixth solution, the processing member (23) is provided between the first electrode (21) and the second electrode (22) and near the second electrode (22). It is characterized by being arranged.

In the seventh solution, when the low-temperature plasma is formed in a flared shape from the first electrode (21) toward the second electrode (22), the plasma generation region becomes the widest in the high-temperature region. A processing member (23) is arranged in the active space.
Therefore, when the fluid to be processed passes through this region,
It passes through the processing member (23) under the action of the plasma.

An eighth solution taken by the present invention is:
The plasma reactor (2) according to the sixth or seventh solution means.
0), the processing member (23) is provided with an opening (23b) through which the fluid to be processed passes along the discharge direction.

In the eighth solution, when the fluid to be processed flows between the first electrode (21) and the second electrode (22), it discharges the opening (23b) of the processing member (23). Pass along the direction. Therefore, the plasma generation region is the second electrode (2
2) When it spreads like a flare toward the side,
The fluid to be processed surely passes through the processing member (23) in the widest part (highly active space) of the plasma.

Further, a ninth solution taken by the present invention is as follows.
In the plasma reactor (20) according to the sixth, seventh, or eighth solution, the processing member (23) has a catalyst substance that promotes processing of the fluid to be processed.

In the ninth solving means, the processing member
Since the catalyst substance is contained in (23), the fluid to be treated is also subjected to the action of the catalyst in addition to the action of the plasma. Specifically, the first electrode (21) and the second electrode (21)
When the fluid to be processed passes between the electrodes (22), low-temperature plasma is generated. Various active species are generated by the low-temperature plasma. These active species include radicals such as hydroxy radicals, excited oxygen molecules, excited nitrogen molecules, and excited water molecules, in addition to ozone. Then, these various active species efficiently react with harmful components and odor components in a highly active state by the action of the catalyst to decompose and remove these substances.

According to a tenth aspect of the present invention, in the plasma reactor (20) according to the sixth, seventh, eighth or ninth aspect, the processing member (23) is provided with It is characterized in that it contains an adsorbent for adsorbing components to be treated contained in the treatment fluid.

In the tenth solution, the component to be treated contained in the fluid to be treated is adsorbed on the adsorbent. Then, the component to be treated adsorbed by the adsorbent is decomposed by plasma. In particular, processing components (2
In the case where the catalyst is provided in 3) and the adsorbent is also included, the adsorbed components are decomposed by the catalyst, so that the decomposition performance is improved.

[0029] An eleventh solution according to the present invention relates to an air purifier using a plasma reactor (20) according to any one of the first to tenth solutions. This air purification device (1) is connected to the plasma reactor (2).
0) is accommodated in the casing (10), and air to be treated is introduced into the casing (10) to pass through the discharge region (S) between the electrodes (21, 22), thereby forming the casing. It is characterized in that it is configured to treat odor components or harmful components in the processing air.

In the eleventh solution, the air to be treated is purified by decomposing odorous or harmful components in the air to be treated by low-temperature plasma generated by streamer discharge. In the case of using the processing member (23) containing a catalyst and an adsorbent, a decomposition action by the catalyst and an adsorption action by the adsorbent are also performed.

[0031]

According to the first solution, the electrode ends (21a) are arranged in a plurality of rows, and each row (L1, L2, L3.
・ ・) Electrode end (21a) with a line perpendicular to each row (L1, L2, L3 ...)
(C1, C2) The electrode end (2
1a) Streamer discharge can be generated with a small gap between them, so that the discharge space (D) between the electrodes (21, 22)
The processing efficiency can be increased by reducing unnecessary gaps in the inside. Further, since the inactivated space between the adjacent discharge regions (S) can be reduced, the device can be downsized.

Further, according to the second solution, the pitch dimension (P1, P2) between the adjacent electrode ends (21a) is reduced, so that a uniform gap is formed between the discharge regions (S). Streamer discharge can be generated with less
More efficient processing becomes possible.

According to the third and fourth solutions, the discharge regions (S) are substantially in contact with each other, so that a streamer discharge is generated in a state where the useless gap is extremely small. Therefore, the processing efficiency can be further improved.

According to the fifth solution, the fluid to be treated flows through the opening (22a) of the second electrode (22) while flowing between the first electrode (21) and the second electrode (22). Since the fluid passes through, the treatment of the fluid to be treated can be ensured. In particular, when the streamer discharge is generated in a region which spreads in a flared manner from the first electrode (21) toward the second electrode (22), the fluid to be treated has a high activity in which the discharge plasma generation region is the widest. Since the gas passes through a small space, the processing efficiency is improved in each stage.

According to the sixth solution, the first solution
Since the fluid to be processed reliably passes through the processing member (23) disposed between the electrode (21) and the second electrode (22) or on the downstream side thereof,
Due to the synergistic effect of the plasma and the processing member (23), the processing of the fluid to be processed is performed more reliably. Therefore, processing performance can be improved.

According to the seventh aspect of the present invention, when plasma is generated in a flared region, the processing member is placed in a highly active space where the plasma generation region is the largest.
Since (23) is located, a synergistic effect between the plasma and the processing member (23) can be further enhanced, and the processing performance can be further enhanced.

Further, according to the eighth solution, when the plasma generation region is flared toward the side of the second electrode (22), the fluid to be processed has the largest spread of the plasma. Since it passes through the portion (highly active space) reliably, the processing efficiency is improved in each step.

Further, according to the ninth solution, the processing member (23) is made to contain a catalytic substance for promoting the processing of the fluid to be treated, so that the fluid to be treated is affected by the plasma and the action of the catalyst. Therefore, the processing performance of the reactor (20) can be improved. Specifically, when a catalytic substance is used, various active species (ozone, hydroxy radicals, excited oxygen molecules, excited nitrogen molecules, excited water molecules, etc.) generated by streamer discharge can be effectively used, so that the processing performance is sufficiently high. To be increased. Further, as described in the first means for solving the above problems, the size of the apparatus can be reduced, so that the amount of catalyst used can be minimized, so that an increase in cost can be suppressed.

The catalyst materials include Pt (platinum), Pd (palladium), Ni (nickel), Ir
(Iridium), Rh (rhodium), Co (cobalt), Os (osmium), Ru (ruthenium), Fe
(Iron), Re (rhenium), Tc (technetium), M
n (manganese), Au (gold), Ag (silver), Cu
(Copper), W (tungsten), Mo (molybdenum), C
At least one of r (chromium) can be used. Among them, some substances such as Fe and Mn may be contained in the processing member (23) in the form of an oxide (eg, Fe ₂ O ₃ , MnO ₂ ).

These catalytic substances are used to decompose components to be treated contained in the fluid to be treated, and to generate various active species (ozone, hydroxyl radicals, excited oxygen molecules, excited nitrogen molecules, excited water molecules) generated by streamer discharge. Etc.) to further excite and enhance the activity, thereby promoting the chemical reaction.

When a manganese-based catalyst is used, a manganese-based catalyst (Mn or Mn oxide (MnO ₂ , Mn ₂ O _3, etc.)) is added to the catalyst component of the processing member (23) in an amount of 10 to 60%.
wt%, preferably 30 to 40 wt%.

As described above, Mn, MnO ₂ , or Mn ₂
When the content of the manganese-based catalyst such as O ₃ is specified, the processing performance of the plasma catalyst reactor (20) can be improved.
Conversely, Mn, MnO ₂ , or Mn in the catalyst component
_If the content such as ₂ O ₃ is too small, the ability to decompose harmful substances will be insufficient, and if the content is too large, the specific surface area of the catalyst will be conversely reduced and the performance will be reduced. can get.

Further, the processing member (23) has manganese oxide (hereinafter referred to as Mn oxide) as a catalyst substance,
Oxide of at least one of iron, cerium, europium, lanthanum, and copper (hereinafter referred to as specific oxide)
And a composite oxide or a composite oxide may be contained.

Among them, the Mn oxide contained in the catalyst decomposes ozone generated by discharge into oxygen and active oxygen. This active oxygen oxidizes harmful components and odor components of the fluid to be treated and decomposes them into harmless components and odorless components. In addition to active oxygen obtained by the decomposition of ozone, radicals such as hydroxy radicals generated by low-temperature plasma, and various active species such as excited oxygen molecules (active oxygen), excited nitrogen molecules, and excited water molecules are catalyzed. It is adsorbed on the surface of the specific oxide contained in (23) or the interface between the Mn oxide and the specific oxide in a radical or excited state. Therefore, many active species having high activity exist as active groups on the surface of the catalyst, and harmful components and odor components in the fluid to be treated are rapidly decomposed.

In this case, the composition ratio of manganese oxide in the catalyst material is preferably set to 20% to 50%. Then,
Since the specific oxide occupies the remainder of the Mn oxide in the catalyst material, its composition ratio is 80% to 50%.

As described above, when the composition ratio of Mn oxide in the catalyst material is set to 20% to 50%, the Mn oxide and the specific oxide are dispersed and refined, and the specific surface area of the catalyst increases. As a result, the interface between the Mn oxide and the specific oxide increases, so that the catalyst adsorbs more active species and the activity is further improved.

Further, the processing member (23) may contain a plurality of kinds of manganese oxides having different oxidation numbers, such as MnO ₂ and Mn ₂ O _3, as a catalyst substance. Then, as compared with the case where the Mn oxide is only one kind, it becomes possible to adsorb more kinds of active species and to perform the reaction during the treatment reaction of the fluid to be treated.

According to the tenth solution, since the components to be treated contained in the fluid to be treated are adsorbed by the adsorbent to perform the decomposition by the plasma, the decomposition performance can be improved. In particular, when the treatment member (23) is provided with a catalyst and also contains an adsorbent, the adsorbed component is treated with the catalyst, so that the treatment performance can be further improved. In addition, if the treatment is performed after the components to be treated are adsorbed, a sufficient treatment can be performed even as an intermittent discharge without performing a continuous discharge, and energy saving can be achieved.

As the adsorbent, for example, at least one of porous ceramics, activated carbon, activated carbon fiber, zeolite (aluminosilicate), mordenite, ferrierite, and silicalite (silica gel) can be used.

According to the eleventh solution, the odor component or the harmful component in the air to be treated can be reliably decomposed by the low-temperature plasma generated by the streamer discharge, so that the air to be treated can be purified efficiently. . Also, processing members
In the case of using a catalyst or an adsorbent in (23), the decomposition action by the catalyst and the adsorption action by the adsorbent are also performed.
Processing performance can be further improved.

[0051]

Embodiment 1 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

This embodiment relates to an air purification device (1) for purifying air by treating odorous or harmful components in the air to be treated by oxidative decomposition or the like. FIG.
1 shows a schematic configuration of the air purification device (1).

As shown in the figure, the air purifying device (1) has a configuration in which each functional component is housed in a casing (10). As the functional components, a dust collecting filter (11) and a centrifugal fan (1) are provided.
2) and the plasma reactor (20) are housed in a casing (10). In FIG. 1, reference numeral (13) denotes an ozone decomposition catalyst for decomposing ozone generated by discharge in the plasma reactor (20).

An air inlet (15) for sucking air into the casing (10) is formed on one side (the right side in the figure) of the casing (10), and a purified air is blown out on the upper surface. Air outlet (16) is formed. Air inlet
(15) is provided with a suction grill (15a) and an air outlet (16)
Is provided with an outlet grill (16a). The dust suction filter (11) is arranged in the air suction port (15) inside the suction grille (15a) so as to collect dust contained in the suction air.

The air outlet (16) is formed on the upper surface of the casing (10) at the edge opposite to the air inlet (15) (the left edge in FIG. 1). And this air outlet
Corresponding to (16), the centrifugal fan (12) is
Is provided within. The centrifugal fan (12) is connected to a fan power supply (12a). In the above configuration,
The inside of the casing (10) has an air inlet (15) and an air outlet
The space between (16) is the circulation space of the air to be treated. When the centrifugal fan (12) is started, air to be processed is sucked into the casing (10) through the suction grill (15a) of the air suction port (15) and the dust filter (11). The air to be treated is
After treatment in the reactor (20) detailed below, the air outlet (1
It is blown out of the casing (10) from the blowout grill (16a) of 6).

FIG. 2 is a sectional view showing a schematic configuration of the plasma reactor (20), and FIG. 3 is a perspective view. This plasma reactor (2
0) is a discharge electrode (first electrode) (21) and a counter electrode (second electrode) (22) which are arranged opposite to each other as discharge means for generating low-temperature plasma, and these electrodes (21, twenty two)
A processing member (23) arranged in close proximity to the counter electrode (22)
And The electrodes (21, 22) are arranged in the flow space of the fluid to be treated, and the processing member (23) is arranged in the discharge space (D) between the electrodes (21, 22). , 22), the fluid to be treated is treated by the streamer discharge.

This processing member (23) is composed of a honeycomb-shaped substrate (23a) having a number of small holes (openings) (23b) penetrating along the direction of air flow, and has a catalyst material on its surface. Is carried. Specifically, the processing member (23) is composed of Pt, Pd, Ni, Ir, Rh, Co,
Os, Ru, Fe, Re, Tc, Mn, Au, Ag, C
It contains at least one of u, W, Mo, and Cr. These catalytic substances promote a chemical reaction when treating the air to be treated.

The processing member (23) also carries an adsorbent together with a catalytic substance on the surface of the substrate (23a). The adsorbent adsorbs components to be treated such as odorous substances and harmful substances contained in the air to be treated, and for example, activated carbon or zeolite is used. As the adsorbent, porous ceramics, activated carbon fiber, mordenite, ferrierite, silicalite, or the like may be used, and at least one of them may be used.

The discharge electrode (21) is composed of an electrode plate (21b) and a plurality of needle electrodes (electrode ends) (21a) fixed substantially perpendicular to the electrode plate (21b). . Electrode plate
(21b) is made of mesh material, punched metal, etc., and has many openings (21
c) Also, an electrode plate having a large number of openings (22a) through which air passes in a direction perpendicular to the plane, such as a mesh material or a punched metal, is used for the counter electrode (22). The discharge electrode (21) is arranged such that the electrode plate (21b) is substantially parallel to the counter electrode (22), and the needle electrode (21a) is substantially perpendicular to the counter electrode (22).

In this example, since the flow direction of the fluid to be treated and the discharge direction are matched, the discharge electrode (2
Both 1) and the counter electrode (22) are made of mesh material or punched metal, and both electrodes have openings (21c, 22a), but the flow direction and discharge direction of the fluid to be treated are different. Depending on the device configuration, such as when
(21c, 22a) may not be necessary.

The needle electrodes (21a) are arranged in a plurality of rows as shown in FIG. 4, and each of the adjacent rows (L1, L2, L3,...)
.) Are not arranged along the orthogonal direction of each row (L1, L2, L3...), For example, the needle electrodes (21a) of the second row (L2) in FIG.
a) is arranged at a position on a line (C2) which is shifted from a line (C1) orthogonal to the upper and lower rows (L1, L3). In the illustrated configuration, the needle electrodes (21a) are alternately positioned for each row.

The arrangement of the needle electrodes (21a) will be described in more detail. The needle electrodes (21a) are arranged at substantially constant intervals in each row (L1, L2, L3...), And Column (L1, L
2, L3 ...), the pitch dimension (P1) between the needle electrodes (21a),
The pitch dimension (P2) between the needle electrodes (21a) in two adjacent rows (L1, L2, L3...) Substantially matches. For this reason,
All the needle electrodes (21a) are arranged at regular intervals. The needle electrodes (21a) are arranged such that the discharge regions (S) generated for each of the needle electrodes (21a) substantially contact each other on the surface of the second electrode (22).

A high-voltage pulse power supply (power supply means) (24) is connected to both electrodes (21, 22). When a discharge voltage is applied to both electrodes (21, 22), the discharge electrodes (21, 22) are connected. ) And the counter electrode (22) to generate a streamer discharge.
Due to this streamer discharge, low-temperature plasma is generated in the discharge space (D). By low temperature plasma, as active species,
Radicals such as fast electrons, ions, ozone, and hydroxyl radicals, and other excited molecules (excited oxygen molecules, excited nitrogen molecules, excited water molecules, and the like) are generated.

In the present embodiment, a discharge is generated in a flare-like wide area (S) for each needle electrode (21c) using a pulse high voltage. Specifically, the pulse rise time is as short as about 100 ns or less, and the pulse width is 1 μm.
By applying a steep pulse high voltage of about s or less between both electrodes, a relatively wide range spread in a flare state is converted into plasma. When the pulse waveform is specified in this way, the reason that the streamer discharge is generated in a wide area is that a short voltage application time makes it possible to instantaneously apply a high voltage that would cause a spark in a normal discharge. Increasing the voltage makes it easier for discharge to occur in all places, the steep rise of the voltage causes less suppression of discharge due to the space charge effect, and the shorter rise time makes it easier for uniform discharge to occur. be able to.

In this embodiment, the pulse high-voltage power supply (24) is used as a power supply, but the power supply is not limited to this, and a DC or AC high-voltage power supply may be used. The streamer discharge does not necessarily have to be generated in a wide flare-like area. However, when the tip shape of the needle electrode is specified (for example, when the tip angle of the needle electrode (21a) is set to 60 °), a direct current is not generated. It is possible to obtain a wide discharge region (S) as in the case of using a steep pulse high voltage even if the high-voltage power supply is used.

-Operating operation- Next, the operating operation of the air purification device (1) will be described.

When the operation of the air purification device (1) is started and the centrifugal fan (12) is started, first, air to be processed is sucked from the air suction port (15), and dust contained in the air is collected. The dust is collected by the dust filter (11). During operation of the device (1), the discharge electrode (21) and the counter electrode (2) of the plasma reactor (20) were
Streamer discharge occurs between 2) and the dust collection filter (1
The air from which dust has been removed in 1) passes through the discharge space (D) between the electrodes (21, 22).

In the present embodiment, each adjacent row (L1, L2, L3.
・ ・) The needle electrode (21a) is a line perpendicular to each row (L1, L2, L3 ...)
(C1, C2) and not on the line (C1, C2) but on the surface of the counter electrode (22) so that the discharge regions (S) are substantially in contact with each other. ing. For this reason, both electrodes
In the discharge space (D) between (21,22), streamer discharge occurs in a state where the gap between the discharge regions (S) is small.

Specifically, when the needle electrodes (21a) are arranged in a grid pattern in the vertical and horizontal directions as in the prior art, a relatively large gap exists between the discharge regions (S) as shown in FIG. However, in this embodiment, since the plurality of discharge regions (S) are substantially in contact with each other on the surface of the counter electrode (22), there is almost no useless gap as shown in FIG. Further, even when the discharge regions (S) are configured to be slightly separated without contacting each other,
The gap between (S) is smaller than in FIG.

As described above, the streamer discharge is generated in a state where the gap between the discharge regions (S) is small, so that low-temperature plasma is efficiently generated spatially. Various kinds of active species generated by this discharge are further highly excited by contacting the catalyst of the processing member (23) to increase the activity, and to reduce harmful substances and odorous substances contained in the air to be processed. It reacts efficiently to decompose and remove these substances.
Therefore, harmful substances and odorous substances in the air are quickly decomposed by a synergistic effect of the plasma and the catalyst.

Further, since the treatment member (23) also contains an adsorbent, harmful substances and odorous substances in the air to be treated are adsorbed by the adsorbent, and the active species of the low-temperature plasma are surely absorbed by these components. Acts to accelerate the decomposition process. In other words, by including the catalyst and the adsorbent in one processing member (23), more stable processing is performed.

According to the first embodiment, the needle electrodes (21a) are arranged in a plurality of rows, and the needle electrodes (L1, L2, L3...)
(21a) is displaced from the line (C1, C2) orthogonal to each column (L1, L2, L3 ...), so that a streamer discharge occurs with a small gap between the discharge regions (S). This makes it possible to reduce the number of inactive regions and increase the processing efficiency.

Further, since the pitch dimension (P1, P2) between the needle electrodes (21a) is set so as to reduce the gap between the discharge regions (S), there is one wasteful gap in the discharge space (D). It will be less. Therefore, the discharge space can be more uniformly used, and the processing can be stabilized.

Further, since the gaps between the discharge regions (S) are reduced by making the respective discharge regions (S) substantially in contact with each other, wasteful space in the discharge space is reduced, and Efficiency can be further increased.

As is apparent from a comparison between FIG. 4 and FIG. 5, in this embodiment, the pitch size of the needle electrode (21a) is
Since (P1, P2) can be reduced uniformly, the apparatus can be made compact.

According to the first embodiment, low-temperature plasma is generated in a wide flare-like area in the discharge space (D) between the discharge electrode (21) and the counter electrode (22). The opposing electrode (2
The opening (22a) is provided in 2) so that the fluid to be processed can pass through, so that the processing of the fluid to be processed can be ensured. Further, since the processing member (23) is arranged in the discharge space (D) so that the air to be processed also passes through the processing member (23) when passing through this space (D), the plasma is generated by the air. In addition to acting on the components to be treated and the components to be treated which are trapped by the adsorbent, they also act on the catalyst, and the treatment of the fluid to be treated is reliably performed by the synergistic effect of the plasma and the catalyst. In particular, since the processing member (23) is arranged near the counter electrode where the plasma spreads most in the discharge space (D), this effect can be ensured. From the above,
The processing performance of the device (1) can be sufficiently improved.

-Example of using other catalyst-(Example 1) When using a manganese-based catalyst as the catalyst,
Mn, MnO ₂ , or Mn ₂ O ₃ is contained in the catalyst component in an amount of 30.
It is good to make it contain -40 wt%. Although this content specifies a suitable range, in the catalyst component, Mn, MnO
₂ or Mn ₂ O ₃ may be contained at 10 to 60 wt%.

A manganese-based catalyst such as Mn, MnO ₂ , or Mn ₂ O ₃ contained in the catalyst decomposes ozone contained in the low-temperature plasma into oxygen and active oxygen. Reacts with substances and odorous substances. In addition, when the above-mentioned other catalyst substances are included, these catalyst substances further excite active species such as active oxygen and various kinds of low-temperature plasma to further increase the activity, so that harmful substances and odor substances in the air are increased. Will be rapidly decomposed by the synergistic effect of the plasma and the catalyst.

[0079] Figure 6, the vertical axis toluene decomposition efficiency according reactor (20), as shown the graph plotting the content of MnO ₂ on the horizontal axis, the MnO ₂ in a catalyst containing 10 to 60 wt% if any can be obtained relatively high decomposition efficiency, especially if a catalyst of MnO ₂ containing 30～40Wt%, it is possible to obtain a very high decomposition efficiency.

(Example 2) A manganese oxide (hereinafter referred to as a Mn oxide) was used as a catalyst material in the treatment member (23).
Oxide of at least one of iron, cerium, europium, lanthanum, and copper (hereinafter referred to as specific oxide)
And a composite oxide or a composite oxide may be contained. The treatment member (23) has a composition ratio of Mn oxide in the catalyst substance of 20% to 50% and a composition ratio of the specific oxide of 80%.
% To 50%. Further, the catalyst material may contain a plurality of types of manganese oxides having different oxidation numbers, such as MnO ₂ and Mn ₂ O ₃ .

When a catalyst comprising manganese, iron and cerium is used as the catalyst, the catalyst can be prepared as follows. That is, first, an aqueous solution of manganese nitrate hexahydrate is prepared as a manganese compound, cerium nitrate hexahydrate as a cerium compound is added thereto, and iron nitrate nonahydrate is further added as an iron compound to obtain a solution A. . On the other hand, a solution B in which an alkali compound is dissolved in water is prepared as a precipitation reagent. Then, a coprecipitate is generated by pouring the liquid A while stirring the liquid B. After aging for 1 hour, the coprecipitate was washed and dried, and calcined in air at a temperature of 500 ° C for 5 hours to obtain a catalyst composed of manganese, iron and cerium. Can be used for the honeycomb-shaped processing member (23).

In the configuration using this catalyst, when the air to be treated passes through the discharge space (D), active species are generated by the action of the streamer discharge, and the harmful substances activated on the catalyst of the processing member (23). Reacts efficiently with odorous substances and
These substances are decomposed and removed. Therefore, harmful substances and odorous substances in the air are quickly decomposed by a synergistic effect of the plasma and the catalyst.

Specifically, the Mn oxide contained in the catalyst decomposes ozone generated by discharge into oxygen and active oxygen. This active oxygen oxidizes harmful components and odor components of the fluid to be treated and decomposes them into harmless components and odorless components. Also,
Including active oxygen obtained by the decomposition of ozone, radicals such as hydroxyl radicals, and various active species such as excited oxygen molecules (active oxygen), excited nitrogen molecules, and excited water molecules,
The surface of the specific oxide contained in the catalyst means (23), M
The active species is adsorbed on the interface between the n-oxide and the specific oxide. Therefore, many active species having high activity exist as active groups on the surface of the catalyst, and harmful components and odor components in the air to be treated are rapidly decomposed.

Thus, the manganese oxide and the specific oxides iron, cerium, europium, lanthanum,
When a catalyst containing a mixture or a composite oxide with at least one oxide of copper and copper is used, various active species generated by the low-temperature plasma are effectively used in the treatment for air purification, and The chemical reaction at the time of treating the processing air can be drastically promoted. Therefore, since the processing capacity of the plasma catalytic reactor (20) can be increased, the capacity of the air purification device (1) can also be increased.

When the composition ratio of Mn oxide in the catalyst material is set to 20% to 50%, the Mn oxide and other specific oxides are dispersed and refined, and the specific surface area of the catalyst increases. The interface between the Mn oxide and the specific oxide increases, and the catalyst adsorbs more active species. Further, by preparing the catalyst containing the Mn oxide and the specific oxide by the coprecipitation method, the Mn oxide and the specific oxide have an effect of refining and increasing the specific surface area of the catalyst. The interface of the specific oxide increases, and many active species can be adsorbed.
The activity is further improved.

By preparing the catalyst by the coprecipitation method, manganese oxides having different oxidation numbers, such as Mn ₂ O _3, are included in the catalyst in addition to MnO _2. Active species can be used,
Activity is further improved. Further, by preparing the catalyst by the coprecipitation method, a large amount of the composite oxide of the Mn oxide and the specific oxide is generated particularly at the interface between the Mn oxide and the specific oxide, so that the Mn oxide (MnO ₂ , A composite oxide (MnCeFe ₂ O ₄ ) having an oxidation number different from that of Mn ₂ O ₃ ) or a specific oxide (Fe ₂ O ₃ , CeO ₂ ) can be obtained, and more kinds of active species can be used. Can be.

When cerium is used as a substance other than manganese, the amount of oxygen that can be used for the reaction on the catalyst increases because CeO ₂ , an oxide thereof, has an oxygen storage capacity. For this reason, the activity during the reaction can be increased as compared with the case where Ce is not used. In addition, europium,
Even if lanthanum or copper is added, more types of active species can be used, so the activity becomes even higher,
The reaction can be accelerated.

[0088]

Other Embodiments of the Invention The present invention may have the following configuration in the first embodiment.

For example, in the above embodiment, the first electrode (21) is provided with the needle electrode as the electrode end (21a). However, as shown in FIG. 7, the first electrode (21) is provided as the electrode end (21a). Electrode plate (2
In 1b), a conductive spherical projection may be provided instead of the needle electrode. Also in this case, the spherical projections are arranged in a plurality of rows as described in the first embodiment, and the spherical projections of each row (L1, L2, L3...) Are arranged in each row (L1, L2, L3.・ ・) Line perpendicular to (C1, C2)
It is arranged to be shifted from above. Even with such a configuration, the spherical projection (21a) of the first electrode (21) and the second electrode (22)
When a streamer discharge occurs between the discharge area (S)
Since a useless gap therebetween is reduced, efficient processing can be performed. In FIG. 7, the openings of the electrodes (21, 22) are shown.
(21c, 22a) and the small holes (23b) of the processing member (23) are omitted.

The electrode end (21a) of the first electrode (21) is not limited to a needle electrode or a spherical projection, but may have another shape.

In the first embodiment, the processing member (23) having the catalyst substance and the adsorbent is disposed between the discharge electrode (21) and the counter electrode (22) near the counter electrode (22). However, the processing member (23) has a counter electrode (23) as shown by an imaginary line in FIG.
May be arranged in the vicinity of the downstream side. The processing member (23)
The processing member (23) may be arranged slightly away from the counter electrode (22), provided that the position is within the range where the plasma acts.
The effect of can be obtained.

Further, instead of the honeycomb-shaped treatment member (23), a member filled with a catalyst particle or an adsorbent particle in a gas-permeable container or the like may be used. Even in this case, the same effect as described above can be obtained.

Further, in the above-described embodiment, one catalyst member (23) performs the function of the catalyst and the function of the adsorbent. However, the first processing member that functions as a catalyst and the second processing member that functions as an adsorbent are used. The two processing members may be separately arranged,
Only one of them may be used.

Further, the plasma reactor of the present invention is not limited to the air purification device (1), but also a nitrogen oxide purification device for treating nitrogen oxides in the gas to be treated, and a nitrogen oxide in the flue gas. Along with other devices that process the fluid to be treated, such as a flue gas purifying device that processes unburned fuel and hydrocarbons, a dioxin decomposing device that processes dioxin in flue gas, or a fluorocarbon gas decomposing device that decomposes fluorocarbon gas The present invention can be applied, and further, can be applied to an air conditioner, a garbage disposal machine, and the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an air purification device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a schematic configuration of a plasma reactor used in the air purification device of FIG.

FIG. 3 is a perspective view showing a schematic configuration of a plasma reactor used in the air purification device of FIG.

FIG. 4 is a diagram showing an arrangement of needle electrodes and a discharge region.

FIG. 5 is a diagram showing a conventional electrode arrangement and a discharge region.

FIG. 6 is a graph showing the toluene decomposition efficiency of a manganese-based catalyst.

FIG. 7 is a perspective view showing an example in which a spherical protrusion is used as an electrode end.

[Explanation of symbols]

 (1) Air purification device (10) Casing (11) Dust collection filter (12) Centrifugal fan (15) Air inlet (16) Air outlet (20) Plasma reactor (21) Discharge electrode (first electrode) ( 21a) Needle electrode (electrode end) (22) Counter electrode (second electrode) (22a) Opening (23) Processing member (23b) Small hole (opening) (24) High voltage power supply (power supply means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kanji Mogi 1304 Kanaokacho, Sakai City, Osaka Prefecture Daikin Industries, Ltd. Sakai Seisakusho Kanaoka Factory F-term (reference) 4C080 AA09 BB02 CC01 QQ11 4G075 AA03 AA37 AA42 BA05 BB04 BD12 CA15 CA47 CA54 CA80 DA02 EB01 EB41 EC21 EE01 EE31 FB02

Claims (11)

[Claims] 1. First electrodes (21) arranged opposite to each other
And a power supply means (24) connected to apply a discharge voltage to both electrodes (21, 22), and the first electrode (21) is connected to the second electrode (22). A plurality of electrode ends (21a) facing each other, the two electrodes (21, 22) are arranged in the flow space of the fluid to be treated, and the fluid to be treated is discharged by the streamer discharge generated between the electrodes (21, 22). A plasma reactor for processing, wherein the electrode ends (21a) are arranged in a plurality of rows, and
(L1, L2, L3 ...) of the electrode end (21a)
3) are arranged at positions deviated from the orthogonal direction of each row (L1, L2, L3...) With respect to the electrode end (21a) of the plasma reactor. 2. An electrode end (21a) of a first electrode (21) is connected to each row (L1,
L2, L3 ...) are arranged at substantially constant intervals, and the pitch between the electrode ends (21a) in each row (L1, L2, L3 ...)
(P1) and two adjacent rows (L1, L2, L3 ...) of the electrode ends (2
2. The plasma reactor according to claim 1, wherein the pitch dimension (P2) between 1a) is substantially the same. 3. The electrode end (21a) of the first electrode (21) is arranged such that discharge regions (S) generated on adjacent electrode ends (21a) substantially contact each other on the second electrode (22). The plasma reactor according to claim 1, wherein the plasma reactor is arranged. 4. First electrodes (21) arranged opposite to each other
And a power supply means (24) connected to apply a discharge voltage to both electrodes (21, 22), and the first electrode (21) is connected to the second electrode (22). A plurality of electrode ends (21a) facing each other, the two electrodes (21, 22) are arranged in the flow space of the fluid to be treated, and the fluid to be treated is discharged by the streamer discharge generated between the electrodes (21, 22). A plasma reactor to be processed, wherein an electrode end (21a) of the first electrode (21) is connected to an adjacent electrode end (21a).
The plasma reactor characterized in that the discharge regions (S) generated for the second electrode (22) are arranged substantially in contact with each other on the second electrode (22). 5. The plasma according to claim 1, wherein the second electrode has an opening through which the fluid to be processed passes along the discharge direction. Reactor. 6. A processing member (2) for processing a fluid to be processed.
3), wherein the processing member (23) is disposed between the first electrode (21) and the second electrode (22) or on the downstream side thereof. 2. The plasma reactor according to 1. 7. The processing member (23) is arranged between the first electrode (21) and the second electrode (22) and near the second electrode (22). 7. The plasma reactor according to 6. 8. The plasma reactor according to claim 6, wherein the processing member has an opening through which the fluid to be processed passes along the discharge direction. 9. The plasma reactor according to claim 6, wherein the processing member (23) has a catalyst substance that promotes processing of the fluid to be processed. 10. The plasma reactor according to claim 6, wherein the processing member includes an adsorbent for adsorbing a component to be treated contained in the fluid to be treated. 11. A plasma reactor (20) according to any one of claims 1 to 10, and a casing (1) in which said plasma reactor (20) is housed.
0), air to be treated is introduced into the casing (10), and the electrodes (21,
22) An air purification device configured to treat odor components or harmful components in the air to be processed by passing through a discharge region (S) between the air purification devices.