JP7168387B2 - plasma reactor - Google Patents

Description

The present disclosure relates to a plasma reactor that generates plasma by energization.

BACKGROUND ART Conventionally, for example, a plasma reactor is known as a device for purifying exhaust gas of an internal combustion engine (engine).
For example, by providing electrodes on the dielectric and applying a voltage between the electrodes to generate low-temperature plasma (non-equilibrium plasma), PM (Particulate Matter) in the exhaust gas flowing between the electrodes is oxidized. are known.

In addition, ozone is generated by a plasma reactor, and this ozone is used to sterilize mold bacteria and suppress spoilage of agricultural products in storage warehouses where agricultural products are stored, indoors such as vinyl houses, and in containers for transporting agricultural products. technology is known.

As a technology of the plasma reactor described above, for example, a device using dielectric barrier discharge has been proposed (see Patent Document 1).
This device consists of a plate-shaped dielectric substrate (panel) provided with a plurality of through holes (discharge holes) through which gas flows, and a pair of electrodes (electrodes) in the substrate so as to sandwich each through hole. That is, a drive electrode for applying a drive voltage is arranged.

Japanese Patent No. 5664792

However, in the prior art described in Patent Document 1, since a pair of + and - electrodes are present on the same substrate, dielectric breakdown may occur if insulation is not sufficient due to, for example, a defect in substrate fabrication. There was a risk of damage to the device due to

As a countermeasure, for example, it is conceivable to sufficiently increase the distance between both electrodes, but in that case, problems such as a decrease in the amount of plasma generated and an increase in the size of the panel arise.

The present disclosure has been made in view of the above problems, and an object thereof is to provide a plasma reactor in which dielectric breakdown is unlikely to occur and plasma can be suitably generated.

(1) A first aspect of the present disclosure is provided with a plurality of electrode panels each having an electrode section in which electrodes are arranged on a dielectric, and the plurality of electrode panels are arranged in parallel at intervals, and the plurality of electrode panels The present invention relates to a plasma reactor that generates plasma by dielectric barrier discharge between them.

In this plasma reactor, the plurality of electrode panels have channels that can supply gas from the first electrode panel side to the second electrode panel side. Furthermore, as gas flow paths, the first electrode panel is provided with a first flow path penetrating the first electrode panel, and the second electrode panel is provided with a second flow path penetrating the second electrode panel. It has

Moreover, when viewed from the arrangement direction in which the first electrode panel and the second electrode panel are arranged, the first electrode panel has its own electrode portion arranged with the first flow path interposed therebetween, In addition, the second electrode panel has its own electrode portion in a region facing the first flow path.

Thus, in the present first aspect, the electrode sections are arranged on the first electrode panel and the second electrode panel which are arranged with a space therebetween. Therefore, when a voltage is applied between the electrodes (specifically, the electrodes) to generate plasma, a conventional single electrode panel with a pair of electrodes is required. The occurrence of dielectric breakdown can be suitably suppressed.

That is, in the first aspect, the different electrode panels arranged in parallel are provided with either + or - electrodes (that is, different electrodes), and a voltage is applied between the electrodes, so that Since the potentials of the electrodes of the individual electrode panels are the same, there is an effect that dielectric breakdown is less likely to occur in each electrode panel itself. Note that when an AC voltage is applied between a pair of electrodes, +/− of each electrode alternately change.

In addition, even if each electrode panel has dimensional variations due to manufacturing defects during mass production, each electrode is formed on a different electrode panel, which also prevents dielectric breakdown. For example, even if the dimensions of the gas flow path are smaller than designed, each electrode is formed on a different electrode panel, so there is an advantage that dielectric breakdown is less likely to occur as in the conventional case.

Furthermore, in the first aspect, since it is not necessary to arrange both the +/− electrodes on one electrode panel, the wiring configuration on one electrode panel can be simplified.
Moreover, the first aspect has the advantage that even if the insulation distance between the electrode panels arranged in parallel (therefore, the insulation distance between the electrodes) is insufficient, it is sufficient to simply adjust the distance between the electrode panels.

In addition, in the first aspect, by arranging a plurality of electrode panels, for example, the PM flowing through the gas flow path can easily pass through the plasma, resulting in a high PM purification capability.
A plasma reactor can also generate ozone from air, for example. In this case, in order to increase the amount of ozone generated and the purification performance by ozone, it is necessary to increase the planar shape of the electrode panel in the conventional technology, but in the present first aspect, the number of electrode panels may be increased. , it is possible to make the device compact.

(2) In the second aspect of the present disclosure, through holes may be employed as the first channel of the first electrode panel and/or the second channel of the second electrode panel.
In other words, a through-hole penetrating through each electrode panel can be employed as the gas flow path of each electrode panel. For example, when the electrode panel is plate-shaped, a through-hole can be employed that penetrates the electrode panel in the thickness direction.

In the case of such a configuration, since the perimeter of the through hole is a frame-like configuration that surrounds the perimeter of the through hole, there is an advantage that the strength of the electrode panel is high and distortion and breakage are less likely to occur.
(3) In the third aspect of the present disclosure, when viewed from the arrangement direction (that is, the direction in which each electrode panel is arranged), the first flow path of the first electrode panel and/or the second The corners around the two flow paths may be R-chamfered.

In this way, when the corners facing the gas flow path of the surrounding members constituting the gas flow path are R-chamfered (thus, when the cross section of the gas flow path is rounded), , the surrounding members (the electrode panel) are less likely to be damaged.

(4) In the fourth aspect of the present disclosure, the plurality of electrode panels may have terminals exposed to the outside, and the terminals may be electrically connected to the electrodes.
Thus, when the electrode panel is provided with terminals, power can be supplied to the electrodes from these terminals. Also, the configuration for supplying power to the electrodes can be simplified.

(5) In the fifth aspect of the present disclosure, an alternating voltage may be applied between the electrodes of the first electrode panel and the electrodes of the second electrode panel.
Thus, by applying an AC voltage between the electrodes of the first electrode panel and the electrodes of the second electrode panel, plasma can be generated between the electrodes (more specifically, between the electrodes). can.

(6) In the sixth aspect of the present disclosure, multiple pairs of first electrode panels and second electrode panels may be provided.
With this configuration, for example, a large amount of plasma can be generated, so that PM and the like can be effectively removed from the exhaust gas, for example.

(7) In a seventh aspect of the present disclosure, the electrode section may include a cantilevered electrode section having one end fixed and the other end free.
In such a case, there is an effect that the electrode panel is less likely to be damaged when the temperature changes.

(8) In an eighth aspect of the present disclosure, the first electrode panel is provided with a cantilevered first electrode section, and the second electrode panel is provided with a cantilevered second electrode section, When viewed from the arrangement direction, the first electrode portion and the second electrode portion are arranged parallel to each other, and are arranged so that their free end sides face the fixed side of the other electrode portion, and , the free end portions of the first electrode portion and the second electrode portion may overlap each other in the parallel extending direction.

In the eighth aspect, when viewed from the arrangement direction, the first electrode portion and the second electrode portion are arranged in parallel, and the free end sides (that is, tip sides) of each other are fixed to the other electrode portion. arranged to face the side. Moreover, the first electrode portion and the second electrode portion have their free end side portions (that is, tip portions) overlapping each other in the parallel extending direction (that is, the direction from the fixed side to the tip side). .

In the case of such a configuration, the flow of gas becomes complicated, so when PM is contained in the exhaust gas, for example, PM is likely to be exposed to plasma. Therefore, there is an advantage that PM and the like can be effectively removed.

Here, "both free ends face the fixed side of the other electrode portion" does not necessarily mean that the tip sides of the two electrode portions extend so as to face each other (that is, on the same axis). In this case, the two electrode portions may be partially or completely misaligned in the direction perpendicular to the direction in which the two electrode portions extend (that is, the parallel direction). For example, when viewed from the wiring direction, the two electrode portions may not overlap each other.

Further, "the free end portions of the first electrode portion and the second electrode portion overlap each other in the parallel extending direction" means "when viewed from the wiring direction, the two electrode portions It does not mean "overlapping", but "that the positions in the parallel direction in which the two electrode portions extend overlap". For example, when both electrode portions extend in the X-axis direction, it indicates that both electrode portions have the same X-coordinate portion.

(9) In the ninth aspect of the present disclosure, the plurality of electrode panels may be fixed by a fixing member on one end side or both end sides in one direction along the surface of the plurality of electrode panels.
Here, the fixing method of the electrode panel is exemplified. When fixing one end side of the electrode panel, the structure for fixing can be simplified. Also, the electrode panel is less likely to be damaged when the temperature changes. On the other hand, fixing both ends of the electrode panel (that is, opposite ends) has the advantage that the electrode panel can be firmly fixed.

(10) In the tenth aspect of the present disclosure, the gas flow paths of the plurality of electrode panels may have a rectangular shape when viewed from the arrangement direction.
Here, the shape of the gas flow path is exemplified. Note that the strip shape indicates an elongated shape such as a rectangle having long sides longer than short sides of a rectangle. For example, the longest dimension in a predetermined direction (the long side in the case of a rectangle) can be, for example, 10 times or more longer than the direction perpendicular to the predetermined direction (the short side in the case of a rectangle).

(11) In the eleventh aspect of the present disclosure, the gas flow paths of the plurality of electrode panels may have a rectangular shape when viewed from the arrangement direction.
Here, the shape of the gas flow path is exemplified.

(12) In the twelfth aspect of the present disclosure, gas flow paths of the plurality of electrode panels may have curved outer peripheries when viewed from the arrangement direction.
Here, the shape of the gas flow path is exemplified. A curved shape such as a circular shape or an elliptical shape can be adopted as the shape of the gas flow path.

(13) In the thirteenth aspect of the present disclosure, the dielectric may be made of a ceramic-based material.
Here, dielectric materials are exemplified. As ceramics, for example, Al ₂ O ₃ , AlN, Y ₂ O ₃ , Si ₃ N ₄ , ZrO ₂ or the like can be used. Other known dielectric materials can be used as the dielectric material. For example, glass, plastic, or the like can be used. In addition to the main component, for example, MgO, CaO, SiO ₂ and the like may be included.

In addition, the main component indicates the largest component amount (for example, volume %, weight %, etc.) (the same applies hereinafter).
(14) In the fourteenth aspect of the present disclosure, the electrode may be made of a material containing tungsten as a main component as the conductive material.

Here, the materials for the electrodes are exemplified. As the conductive material, Cu, Al, Pt, Mo, _RuO2 , etc. can be used in addition to tungsten (W). In addition, a mixture of W and Mo may be included in addition to the main component.

(15) In the fifteenth aspect of the present disclosure, the electrode section may have a shape extending in the longitudinal direction, and may have a circular shape when the electrode section is cut perpendicular to the longitudinal direction.
Here, the shape (that is, cross-sectional shape) of the electrode portion is exemplified. When the cross-sectional shape of the electrode portion is circular, for example, when PM is contained in exhaust gas, PM tends to adhere to the surface of the electrode portion. Therefore, the PM adhering to the surface of the electrode portion can be favorably burned (that is, oxidized) by the generated plasma.

(16) In the sixteenth aspect of the present disclosure, the electrode section has a shape extending in the longitudinal direction, the shape of the electrode section cut perpendicular to the longitudinal direction is a rhombus, and the opposing vertices of the rhombus are gas It may be arranged along the flow path.

Here, the shape (that is, cross-sectional shape) of the electrode portion is exemplified. When the cross-sectional shape of the electrode portion is a rhombus in the direction described above, for example, when PM is contained in the exhaust gas, the PM tends to adhere to the surface of the electrode portion. Therefore, the PM adhering to the surface of the electrode portion can be favorably burned (that is, oxidized) by the generated plasma.

(17) In the seventeenth aspect of the present disclosure, when viewed from the arrangement direction, the plurality of electrode portions are provided with a shape extending in the longitudinal direction, and the plurality of electrode portions are arranged at intervals in the lateral direction. and if there are multiple spaces, at least two spaces may have different dimensions.

Here, the shapes of electrode portions and gaps provided in the electrode panel are illustrated.

FIG. 2 is an explanatory view showing the internal configuration and the like of the PM removing device of the first embodiment, partly cut away; FIG. 2A is a front view showing the first and second electrode panels of the first embodiment viewed from the upstream side, and FIG. 2B is a rear view showing the first and second electrode panels viewed from the downstream side. It is a diagram. 4 is a cross-sectional view showing an enlarged part of the AA cross section of the first and second electrode panels, etc. of the first embodiment; FIG. It is explanatory drawing which shows operation|movement of PM removal apparatus of 1st Embodiment. 5A is a front view showing part of the first and second electrode panels of Modification 1 as seen from the upstream side, and FIG. 5B is a part of the first and second electrode panels seen from the downstream side. FIG. 10 is a rear view showing a folded state; FIG. 6A is a front view showing part of the first and second electrode panels of Modification 2 as seen from the upstream side, and FIG. 6B is a part of the first and second electrode panels seen from the downstream side. FIG. 10 is a rear view showing a folded state; FIG. 11 is a front view showing a state of part of the first and second electrode panels of Modification 3 as viewed from the upstream side; 8A is a cross-sectional view showing a part of the AA cross section along the YZ plane of the electrode panel of Modification 4, and FIG. 8B is a cross-sectional view showing a part of the AA cross section of the electrode panel of Modification 5. . 9A is a front view showing part of the first and second electrode panels of the second embodiment viewed from the upstream side, and FIG. 9B is a part of the first and second electrode panels viewed from the downstream side. It is a back view which shows the state seen. FIG. 10A is a front view showing part of the first and second electrode panels of the third embodiment viewed from the upstream side, and FIG. 10B is a part of the first and second electrode panels viewed from the downstream side. It is a back view which shows the state seen. FIG. 11A is a front view showing part of the first and second electrode panels of the fourth embodiment viewed from the upstream side, and FIG. 11B is a part of the first and second electrode panels in the Y-axis direction. is an explanatory view showing a state seen from above. FIG. 12A is a front view showing the state of the first electrode panel of the example of the fourth embodiment as seen from the upstream side, and FIG. 12B is an explanatory diagram showing the arrangement of the first electrodes of the first electrode panel. . It is explanatory drawing which shows the ozone generator of 5th Embodiment.

Next, embodiments of the plasma reactor of the present disclosure will be described.
[1. embodiment]
[1-1. PM removal device]
First, a PM removal apparatus equipped with a plasma reactor of this embodiment will be described.

As shown in FIG. 1, the PM removal device 1 in this embodiment is a device for removing PM contained in the exhaust gas (G) of an automobile engine (not shown), and is attached to an exhaust pipe 3. . This PM removal apparatus 1 includes a flow tube 5 , a plasma reactor 7 and an AC power supply 9 . Note that FIG. 1 shows the shape viewed from the X-axis direction in an X, Y, Z orthogonal coordinate system.

The flow pipe 5 is made of stainless steel, for example, and has a tubular shape (cylindrical shape) having an exhaust gas inlet 11 and an exhaust gas outlet 13 at one end and the other end, respectively. The exhaust gas inlet 11 is connected to an engine-side portion 3a of the exhaust pipe 3, and the exhaust gas outlet 13 is connected to a portion 3b of the exhaust pipe 3 opposite to the engine side.

Exhaust gas from the engine flows through the engine-side portion 3a of the exhaust pipe 3, flows into the circulation pipe 5 from the exhaust gas inlet 11, passes through the circulation pipe 5, and exits the exhaust gas outlet 13 on the engine side of the exhaust pipe 3. flows out to the portion 3b on the opposite side. That is, the exhaust gas flows from the left side (that is, upstream side) to the right side (that is, downstream side) in FIG. 1, as indicated by the arrows in FIG.

The plasma reactor 7 is a plasma generator that uses an AC voltage from an AC power supply 9 to generate plasma by dielectric barrier discharge.
The plasma reactor 7 is arranged in the flow pipe 5, and includes a plurality of electrode panels DP (specifically, first to sixth electrode panels 21, 22, 23, 24, 25, and 26), and each electrode panel DP and a pair of fixing members 27 and 29 for fixing.

Each electrode panel DP has a flat plate shape, and is arranged at a predetermined interval ( For example, they are arranged in parallel with an interval of 0.5 mm (that is, they are arranged in parallel).

Each electrode panel DP has a rectangular shape when viewed from the Z-axis direction (see FIG. 2), and is arranged so that the rectangular plane extends along a direction perpendicular to the Z-axis direction (that is, the XY plane). Although a rectangle having short sides and long sides is exemplified here, a square may be used.

Above and below each electrode panel DP (that is, above and below in FIG. 1), a first fixing member 27 and a second fixing member 29 each having a flat plate shape are arranged along the XZ plane. there is A groove 31 extending in the X-axis direction is provided on one surface of each of the fixing members 27 and 29 (that is, the surface on the side of the electrode panel DP). Each electrode panel DP is positioned and fixed by fitting the upper and lower portions of each electrode panel DP into the upper and lower grooves 31 .

Although not shown, both fixing members 27 and 29 are fixed to the flow pipe 5 , thereby fixing the plasma reactor 7 to the flow pipe 5 . Here, for convenience of explanation, a structure in which six electrode panels DP are arranged in parallel is illustrated, but the structure is not limited to this, and for example, more electrode panels DP may be arranged.

[1-2. electrode panel]
Next, the electrode panel DP, which is a main part of the plasma reactor 7, will be described.
The six electrode panels 21-26 are configured to generate plasma between a pair of adjacent electrode panels DP. That is, the six electrode panels 21-26 are composed of three pairs of electrode panels DP.

Specifically, the configurations of the first electrode panel 21, the third electrode panel 23 and the fifth electrode panel 25 are the same, and the configurations of the second electrode panel 22, the fourth electrode panel 24 and the sixth electrode panel 26 are the same. and the configuration are the same.

The first electrode panel 21, the third electrode panel 23, and the fifth electrode panel 25 are electrically connected to one output terminal 9a of the AC power source 9 so that the same voltage is applied from the AC power source 9. properly connected. On the other hand, the second electrode panel 22, the fourth electrode panel 24, and the sixth electrode panel 26 are electrically connected to the other output terminal 9b of the AC power source 29 so that the same voltage is applied from the AC power source 9. properly connected.

Thereby, between the first electrode panel 21 and the second electrode panel 22, between the second electrode panel 22 and the third electrode panel 23, and between the third electrode panel 23 and the fourth electrode Plasma is similarly generated between the panel 24, between the fourth electrode panel 24 and the fifth electrode panel 25, and between the fifth electrode panel 25 and the sixth electrode panel 26. be able to.

That is, in the first embodiment, a plurality of pairs (here, three pairs) of electrode panels DP having the same configuration as the first electrode panel 21 and the second electrode panel 22 are provided. As described above, plasma can be similarly generated between a pair of adjacent electrode panels DP among the six electrode panels DP.

Therefore, the first electrode panel 21 and the second electrode panel 22 will be described below as an example.
As shown in FIG. 1, the first electrode panel 21 has a first substrate 33 with a first electrode 35 embedded therein, and the second electrode panel 22 has a second substrate 37 with a second electrode 35 embedded therein. An electrode 39 is embedded.

Specifically, as shown in FIG. 2, for example, the first electrode panel 21 (that is, the panel shown in white in FIG. 2) has a rectangular shape when viewed from the Z-axis direction, and a rectangular shape when viewed from the same direction. A linear first electrode 35 is embedded in a first substrate 33 .

The first substrate 33 is made of a dielectric material, for example, a ceramic whose main component is alumina (for example, 92 volume percent of alumina), and the first electrode 35 is made of a material whose main component is tungsten (for example, 95 volume percent of tungsten). Become.

The first substrate 33 includes a pair of left and right vertical frame portions 41 extending in the Y-axis direction, and a plurality of horizontal frame portions 43 extending in the X-axis direction so as to connect the left and right vertical frame portions 41 . .
The first electrode 35 includes a vertical electrode 35a extending in the Y-axis direction along one vertical frame portion 41 (on the left side in FIG. 2A), and a vertical electrode 35a branched from the vertical electrode 35a and extending in the X-axis direction on the right side in FIG. 2A. and an extending horizontal electrode 35b. A plurality of horizontal electrodes 35b are arranged in parallel at regular intervals along the Y-axis direction. With this configuration, the first electrode 35 has a configuration of a so-called comb-teeth electrode.

In the first electrode panel 21, the horizontal frame portion 43, which is a dielectric, and the horizontal electrode 35b embedded in the horizontal frame portion 43 constitute an electrode portion 45 for generating plasma. Accordingly, the arrangement and shape of the electrode portion 45 are the same as those of the horizontal frame portion 43 .

A square notch 47 is provided on the surface of the corner (upper left corner in FIG. 2A) of the first electrode panel 21 (front surface in FIG. 2A: upstream side). , a portion (that is, a first exposed terminal) 49 where the first electrode 35 is exposed is provided.

Further, the first electrode panel 21 is provided with a through hole (that is, the first flow path 51) that penetrates the first electrode panel 21 in the thickness direction as a flow path R for the exhaust gas. That is, the first flow path 51 is a space surrounded by a pair of left and right vertical frame portions 41 and a pair of upper and lower adjacent horizontal frame portions 43 (thus, the electrode portions 45).

The shape of the first flow path 51 when viewed from the Z-axis direction is a rectangle (specifically, a rectangular shape) among quadrangles.
On the other hand, as shown in FIG. 2B, the second electrode panel 22 (that is, the panel shown in gray in the figure) has the same configuration as the first electrode panel 21, and has a rectangular shape when viewed from the Z-axis direction. A linear second electrode 39 is embedded in a second substrate 37 .

That is, the second electrode panel 22 has a configuration in which the first electrode panel 21 is rotated by 180 degrees on the XY plane (that is, turned upside down). The exposed portion (that is, the second exposed terminal) 53 of the second electrode 39 is on the upstream side (back side of the paper).

Similarly to the first electrode 35, the second electrode 39 includes a vertical electrode 39a and a horizontal electrode 39b. 39b constitute an electrode portion 57 of the second electrode 39. As shown in FIG.

Further, the second electrode panel 22 is also provided with a through-hole (that is, the second flow path 59) that penetrates the second electrode panel 22 in the thickness direction as a flow path R for the exhaust gas. The shape of this second flow path 59 is similar to that of the first flow path 51 .

In addition, the cross-sectional shape along the YZ plane of each of the electrode portions 45 and 57 is rectangular (for example, square). That is, as shown in FIG. 3, the upper and lower sides of the rectangle are parallel to the Z-axis direction, and the left and right sides are parallel to the Y-axis direction.

Particularly in the first embodiment, as shown in FIG. 2A, when viewed from the Z-axis direction, the first electrode panel 21 has its own electrode portion 45 arranged with the first flow path 51 interposed therebetween. In addition, the second electrode panel 22 has its own electrode portion in the area facing the first flow path 51 (that is, the area where the first flow path 51 is projected to the downstream side). 57 exist.

Moreover, since the vertical dimension of the first channel 51 is longer than the vertical dimension of the electrode portion 57 of the second electrode panel 22, when viewed from the Z-axis direction, the second electrode panel 22 A slight strip-shaped gap 60 is provided above and below the electrode portion 45 of .

Therefore, in the first embodiment, as shown in FIG. 3, the exhaust gas supplied from the upstream side on the left side of FIG. The gas passes through the second flow path 59 of the electrode panel 22, and similarly thereafter passes through the gas flow paths R of the third to sixth electrode panels 23 to 26 downstream.

One output terminal 9 a of the AC power source 9 is electrically connected to the first exposed terminal 49 of the first electrode 35 , and the second exposed terminal 53 of the second electrode 39 is connected to the AC power source 9 . The other output terminal 9b is electrically connected.

As will be described later, an AC voltage is applied between the electrodes 35 and 39 of the pair of adjacent electrode panels DP. occurs. For example, as shown in FIG. 3, between the lower right corner of the electrode portion 45 at the upper end of the first electrode panel 21 and the upper left corner of the electrode portion 57 at the upper end of the second electrode panel 22, or , between the upper right corner of the second electrode portion 45 from the top of the first electrode panel 21 and the lower left corner of the electrode portion 57 at the upper end of the second electrode panel 22. Plasma is generated in a region or the like connecting between 45 and 57 with the shortest distance.

[1-3. Electrode panel manufacturing method]
Next, a method for manufacturing the electrode panel will be briefly described by taking the first electrode panel 21 as an example. The method for manufacturing other electrode panels DP is the same.

First, as a material for the first substrate 33, which is a dielectric material, a ceramic green sheet containing ceramic such as alumina as a main component is produced, as is well known, though not shown.
Next, in order to form the first electrode 35, as is well known, screen printing or the like is used to print a conductive paste such as a tungsten paste on the surface of the ceramic green sheet. A pattern of electrodes 35 is formed.

Next, another ceramic green sheet is laminated on the ceramic green sheet printed with the conductive paste to form a green sheet laminate. A notch for exposing the first exposed terminal 49 is formed in another ceramic green sheet.

Next, the first electrode panel 21 is produced by firing the green sheet laminate. The first exposed terminal 49 of the first electrode 35 is plated with Ni or the like.
[1-4. Operation of PM removal device]
Next, the operation of the PM removing device 1 will be briefly described with reference to FIG.

As shown in FIG. 4, when the PM removing device 1 is in an operating state, an AC voltage is applied from the AC power supply 9 to each electrode panel DP. That is, voltages with opposite +/- are applied to adjacent electrode panels DP. For example, an AC voltage with a frequency of 20 kHz and a maximum voltage of 5 kV is applied.

In this state, when the exhaust gas is supplied from the upstream side and PM is contained in the exhaust gas, the PM flows downstream along the flow of the exhaust gas.
Specifically, the exhaust gas passes along the gas flow path R from the first flow path 51 of the first electrode panel 21 through the second flow path 59 of the second electrode panel 22, and so on. After the third electrode panel 23 , the gas flows downstream through the gas flow path R.

At this time, an AC voltage is applied to the electrodes 35 and 39 (therefore, the electrode portions 45 and 57) of each electrode panel DP. , 57, and burned by plasma generated between the electrode portions 45 and 57 of each electrode panel DP to become gases such as CO ₂ and CO, for example. That is, PM is removed by oxidation of PM.

[1-5. effect]
Next, the effects of the first embodiment will be described.
(1) In the first embodiment, the electrode sections are arranged on the respective electrode panels DP arranged at intervals. Therefore, when a voltage is applied between the electrode portions 45 and 57 (specifically, the electrodes 35 and 39) to generate plasma, it is necessary to provide a pair of electrodes on one conventional electrode panel. The occurrence of dielectric breakdown can be suitably suppressed.

In addition, even if the electrode panels DP have dimensional variations due to manufacturing defects during mass production, the electrodes 35 and 39 are formed on different electrode panels DP, and therefore dielectric breakdown can be suppressed.

Furthermore, since it is not necessary to arrange both the +/− electrodes 35 and 39 on one electrode panel DP, the wiring configuration for one electrode panel can be simplified.
Moreover, even if the insulation distance between the electrode panels DP arranged in parallel (therefore, the insulation distance between the electrodes) is insufficient, there is the advantage that the distance between the electrode panels DP can be simply adjusted.

In addition, by arranging a plurality of electrode panels DP, the PM flowing through the gas flow path can easily pass through the plasma, resulting in a high PM purification capability.
(2) In the first embodiment, the first flow path 51 of the first electrode panel 21 and the second flow path 59 of the second electrode panel are through holes. Therefore, since the electrode panel DP has a frame-like structure around the through hole, the electrode panel DP has a large strength, and there is an advantage that the electrode panel DP is less likely to be distorted or damaged.

(3) In the first embodiment, since each electrode panel DP is provided with the exposed terminals 49 and 53, power can be supplied from the exposed terminals 49 and 53 to the electrodes 35 and 39. FIG. Moreover, the configuration for supplying power to the electrodes 35 and 39 can be simplified.

(4) In the first embodiment, a plurality of pairs of structures similar to the first electrode panel 21 and the second electrode panel 22 are provided. Therefore, PM and the like can be effectively removed from the exhaust gas.

(5) In the first embodiment, the upper and lower ends of the electrode panel DP are fixed by fixing members 27 and 29, respectively. With this configuration, the electrode panel DP can be easily fixed.
[1-6. Modification]
Next, a modified example of the first embodiment will be described. In addition, the same numbers are used to describe the same configurations as in the first embodiment.

(1) In Modification 1, as shown in FIG. 5, both the first exposed terminal 49 of the first electrode panel 21 and the second exposed terminal 53 of the second electrode panel 22 are connected It may be arranged on the same side of the DP (for example, on the top of the figure).

That is, as shown in FIG. 5A, the first exposed terminal 49 is arranged on the surface of the first electrode panel 21 on the upstream side, and as shown in FIG. 5B, the second exposed terminal 53 is arranged as the second electrode. It may also be located on the downstream surface of panel 22 . Both of the exposed terminals 49 and 53 can be arranged on the surface of the electrode panel DP on the upstream side or the surface on the downstream side (the same applies to other embodiments and the like).

(2) In Modification 2, as shown in FIG. 6A, the first exposed terminal 49 of the first electrode panel 21 is placed between the upper and lower ends of the vertical electrodes 35a instead of the upper and lower ends of the vertical electrodes 35a. may be placed.

Similarly, as shown in FIG. 6B, the second exposed terminals 53 of the second electrode panel 22 may be positioned between the top and bottom ends of the vertical electrodes 39a instead of the top or bottom ends of the vertical electrodes 39a. .
(3) In Modified Example 3, as shown in FIG. 7, the corners 52 of the rectangular first channel 51 of the first electrode panel 21, i.e., the portions corresponding to the vertices of the rectangle, have a smoothly curved R shape. It's becoming

This has the advantage of improving the strength of the first electrode panel 21 . The configuration of other electrode panels DP is the same.
(4) In Modified Example 4, as shown in FIG. 8A, the cross-sectional shape of the electrode portions 45 and 57 of the electrode panel DP along the YZ plane is a shape having a curved outer circumference (for example, circular).

Therefore, since PM easily adheres to the surfaces of the electrode portions 45 and 57, there is an advantage that the PM cleaning performance is high.
(5) Similarly, in Modified Example 5, as shown in FIG. 8B, the cross-sectional shape along the YZ plane of the electrode portions 45 and 57 of the electrode panel DP is a rectangular (for example, square) oblique shape, for example, For example, a square is rotated by 45 degrees (for example, becomes a diamond shape), and its vertices face the upstream side and the downstream side.

Therefore, since PM easily adheres to the surfaces of the electrode portions 45 and 57, there is an advantage that the PM cleaning performance is high.
(6) In modification 6, although not shown, one of the pair of fixing members 27 and 29 may be used to position and fix the electrode panel DP.

(7) In Modified Example 8, although not shown, a polygonal shape other than a quadrangle can be adopted as the shape (shape viewed from the Z-axis direction) of the gas channel R such as the first channel 51 . Also, a smoothly curved shape such as a circle or an oval can be adopted. Furthermore, polygons and curved shapes may be combined.

(8) Although not shown, the shapes of the gas flow paths R of the plurality of first flow paths 51 and the like (shapes viewed from the Z-axis direction) may all be the same. may be different. For example, in the same or different electrode panels DP, some or all of the dimensions in the vertical direction (that is, the Y-axis direction) of the plurality of gas flow paths R may be different.

[2. Second Embodiment]
Next, the second embodiment will be described, but descriptions of the same contents as in the first embodiment will be omitted or simplified.

As shown in FIG. 9, in the second embodiment, in each electrode panel DP (for example, the first electrode panel 61 and the second electrode panel 63), the first electrode portion 65 and the second electrode portion 67 are , is cantilevered with one end fixed and the other end free.

Specifically, as shown in FIG. 9A, for example, the first electrode panel 61 has a vertical frame portion 69 extending in the Y-axis direction on the left side of the figure. A plurality of cantilevered horizontal frame portions 71 (thus, the first electrode portions 65) extend from the vertical frame portion 69 toward the right side of the figure. That is, since there is no vertical frame portion on the right side of the figure, the distal end of the horizontal frame portion 71 (therefore, the first electrode portion 65) protrudes into the air.

Since the first electrodes 73 are arranged in the same manner as in the first embodiment (that is, in the form of comb teeth), the first electrode portion 65 in which the horizontal electrodes 73b are arranged on the horizontal frame portion 71 is also cantilevered. It has become. Therefore, the first electrode panel 61 has a comb shape when viewed from the Z-axis direction.

The second electrode panel 63 also has the same configuration as the first electrode panel 61, although the arrangement (that is, top and bottom) is different from that of the first electrode panel 61, as in the first embodiment.
The second embodiment has the same effect as the first embodiment. In addition, there is an advantage that the electrode panel DP is less likely to be damaged even if the electrode portions 65, 67, etc. expand or contract when there is a change in temperature.

[3. Third Embodiment]
Next, the third embodiment will be described, but descriptions of the same contents as those of the second embodiment will be omitted or simplified.

As shown in FIG. 10, in the third embodiment, in each electrode panel DP (for example, the first electrode panel 81 and the second electrode panel 83), the first electrode portion 85 and the second electrode portion 87 are , is cantilevered with one end fixed and the other end free.

Specifically, as shown in FIG. 10A, for example, the first electrode panel 81 has a pair of vertical frame portions 91 and 93 extending in the Y-axis direction and upper end portions of the vertical frame portions 91 and 93 on the left and right sides of the figure. An upper end frame portion 94 extending in the X-axis direction is provided for connection.

Further, below the upper end frame portion 94, cantilevered horizontal frame portions 95 and 97 (thus, the left electrode portion 99 and the left electrode portion 99 and the left electrode portion 99 and A plurality of right electrode portions 101) extend.

In other words, the pair of left and right electrode portions (that is, the left electrode portion 99 and the right electrode portion 101) protrude at the same position in the vertical direction so that the tip sides face each other. That is, the pair of left and right electrode portions 99 and 101 are arranged on the same line in the X-axis direction, and there is a gap 103 at the tip of the left and right electrode portions 99 and 101 .

The first electrode 105 is embedded along both vertical frame portions 91 and 93 and the upper end frame portion 94 . Horizontal electrodes 111 and 113 branch from the vertical electrodes 107 and 109 in the vertical frame portions 91 and 93 and extend along the left and right electrode portions 99 and 101, respectively.

The second electrode panel 83 is arranged by turning the first electrode panel 81 upside down, as shown in FIG. 10B.
The third embodiment has the same effect as the second embodiment.

[4. Fourth Embodiment]
Next, the fourth embodiment will be described, but descriptions of the same contents as in the third embodiment will be omitted or simplified.

The fourth embodiment is basically the same as the third embodiment, but the lengths of the opposing left and right electrode portions are different.
As shown in FIG. 11A, in the fourth embodiment, the first electrode panel 121 includes a cantilevered first electrode portion 123 extending in the X-axis direction. The first electrode portion 123 is composed of a cantilevered left electrode portion 125 on the left side of the figure and a cantilevered right electrode portion 127 on the right side of the figure. shorter. As in the third embodiment, the left and right electrode portions 125 and 127 extend so that their tip sides face each other, and there is a first gap 129 on the tip side.

Similarly, the second electrode panel 131 includes a cantilevered second electrode portion 133 extending in the X-axis direction. The second electrode portion 133 is composed of a cantilevered left electrode portion 135 on the left side of the figure and a cantilevered right electrode portion 137 on the right side of the figure. is longer than As in the third embodiment, the left and right electrode portions 135 and 137 extend so that their tip sides face each other, and there is a second gap 139 on the tip side.

The second electrode panel 131 is arranged by turning the first electrode panel 121 upside down.
In the fourth embodiment, as described above, the left electrode portion 125 of the first electrode panel 121 is shorter than the right electrode portion 127, while the left electrode portion 135 of the second electrode panel 131 is shorter than the right electrode portion. Since it is longer than the portion 137, the positions of the first gap 129 and the second gap 139 are shifted in the X-axis direction, as shown in FIG. 11B.

That is, the first electrode portion 123 (for example, the right electrode portion 127) and the second electrode portion 133 (for example, the left electrode portion 135) are arranged parallel to each other, and the free end sides thereof It is arranged so as to face the fixed side of 135 . Here, when viewed from the Z-axis direction, the adjacent right electrode portion 127 and left electrode portion 135 do not overlap.

Moreover, the free end portions of the first electrode portion (for example, the right electrode portion 127) and the second electrode portion (for example, the left electrode portion 135) are overlapped in the parallel extending direction (X-axis direction). there is That is, although the X coordinates of the tips of the right electrode portion 127 and the left electrode portion 135 that are adjacent to each other in the X-axis direction are different, the tip portions (that is, portions near the tips) of the right electrode portion 127 and the left electrode portion 135 are different. have parts with the same X coordinate.

The fourth embodiment has the same effect as the third embodiment. Further, in the fourth embodiment, since the positions of the first gap 129 and the second gap 139 are shifted in the X-axis direction, PM flowing through the gas flow path R may be exposed to plasma. Since it becomes high, there is an advantage that the purification ability of PM is high.

(Example)
A more detailed example of the fourth embodiment will now be described.
As shown in FIG. 12A, in this embodiment, the first electrode panel 141 includes a frame portion 144 having a rectangular outer periphery and forming a first substrate 143 . The frame portion 144 includes a pair of left and right vertical frame portions 145 and 147 extending in the Y-axis direction, and an upper horizontal frame portion 149 and a lower horizontal frame portion 151 extending in the X-axis direction.

From the left and right vertical frame portions 145 and 147, a left electrode portion 153 and a right electrode portion 155 having different lengths (that is, different lengths on the left side and the right side) are arranged to face each other as in FIG. 11A. In addition, it protrudes toward the center in the left-right direction. Therefore, the position of the gap 157 between the left electrode portion 153 and the right electrode portion 155 is shifted slightly rightward from the center. The left electrode portions 153 have the same length, and the right electrode portions 155 also have the same length.

A plurality of left electrode portions 153 and right electrode portions 155 are arranged. ) are the same. Also, the width between the first electrode portions 159 is the same. The width between the first electrode portions 159 is the same as the width of the first electrode portions 159, but may be different.

The first electrodes 161 embedded in the first electrode panel 141 are arranged as shown in FIG. 12B. In addition, in FIG. 1, the position of the first electrode 161 is indicated by a solid line for easy understanding.

Also, although not shown, the second electrode panel is arranged by turning the first electrode panel 141 upside down.
Here, the widths (dimensions in the Y-axis direction) of the upper horizontal frame portion 149 and the lower horizontal frame portion 151 are set to be different. That is, the width of the lower horizontal frame portion 151 is set longer than the width of the upper horizontal frame portion 149 by, for example, the width of one first electrode portion 159 . Therefore, when the second electrode panel is arranged on the downstream side of the first electrode panel 141 , the second electrodes of the second electrode panel are placed between the first electrode portions 159 of the first electrode panel 141 . An electrode part is located.

[5. Fifth Embodiment]
Next, the fifth embodiment will be described, but descriptions of the same contents as in the first embodiment will be omitted or simplified.

The fifth embodiment uses the plasma reactor of the first embodiment or the like as an ozone generator.
As shown in FIG. 13, an ozone generator 161 of the fifth embodiment includes a plasma reactor 163 having the same configuration as that of the first embodiment, and a fan 165 that supplies air to the plasma reactor (that is, blows air). ing.

This ozone generator 161 generates ozone by reacting air (that is, oxygen) sent by a fan with plasma.
That is, the AC power supply 167 applies an AC voltage to the electrode panels DP arranged in parallel, whereby the plasma generated between the electrode panels DP can efficiently generate ozone.

[6. Other embodiments]
The present disclosure is by no means limited to the above-described embodiments, and it goes without saying that various aspects can be implemented without departing from the scope of the present disclosure.

(1) For example, the shapes of the electrode panel, the electrodes, the electrode portions, etc. are not limited to the above-described embodiments.
(2) Further, the application of the plasma reactor is not limited to the PM removing device or the ozone generating device.

(3) It should be noted that the function of one component in each of the above embodiments may be assigned to a plurality of components, or the function of a plurality of components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Also, at least a part of the configuration of each of the above embodiments may be added, replaced, or the like with respect to the configuration of another embodiment. It should be noted that all aspects included in the technical idea specified by the wording in the claims are embodiments of the present disclosure.

7, 163... Plasma reactor 21, 66, 81, 121, 141... First electrode panel 22, 63, 83, 131... Second electrode panel 27... First fixing member 29... Second fixing member 35, 73... 1st electrode 39... 2nd electrode 45, 65, 85, 125, 159... 1st electrode part 49... 1st exposed terminal 51... 1st flow path 53... 2nd exposed terminal 57, 67, 87, 133... Second electrode part 59... Second flow path DP... Electrode panel

Claims (17)

A plurality of electrode panels each having an electrode portion in which electrodes are arranged on a dielectric are provided, and the plurality of electrode panels are arranged in parallel at predetermined intervals in a gas flow direction. A plasma reactor for generating plasma by dielectric barrier discharge in
The plurality of electrode panels have flow paths capable of supplying the gas from the first electrode panel side to the second electrode panel side,
As the flow path of the gas, the first electrode panel is provided with a first flow path penetrating the first electrode panel, and the second electrode panel is provided with a second flow path penetrating the second electrode panel. with a flow path of
the gas is configured to pass through the second flow path after passing through the first flow path;
When viewed from the arrangement direction in which the first electrode panel and the second electrode panel are arranged,
The first electrode panel has its own electrode part disposed across the first flow channel, and the second electrode panel has a region facing the first flow channel. has its own electrode portion,
plasma reactor. the first channel of the first electrode panel and/or the second channel of the second electrode panel are through holes;
A plasma reactor according to claim 1. When viewed from the arrangement direction,
corners around the first channel of the first electrode panel and/or the second channel of the second electrode panel are R-chamfered;
3. The plasma reactor according to claim 1 or 2. The plurality of electrode panels have terminals exposed to the outside, and the terminals are electrically connected to the electrodes.
The plasma reactor according to any one of claims 1-3. applying an alternating voltage between the electrodes of the first electrode panel and the electrodes of the second electrode panel;
The plasma reactor according to any one of claims 1-4. A plurality of pairs of the first electrode panel and the second electrode panel,
The plasma reactor according to any one of claims 1-5. As the electrode part, a cantilevered electrode part with one end fixed and the other end free end is provided,
The plasma reactor according to any one of claims 1-6. The first electrode panel is provided with the cantilevered first electrode portion, and the second electrode panel is provided with the cantilevered second electrode portion,
When viewed from the arrangement direction,
The first electrode portion and the second electrode portion are arranged parallel to each other, and are arranged so that their free ends face the fixed side of the other electrode portion,
Further, free end portions of the first electrode portion and the second electrode portion are overlapped in positions in the parallel extending direction.
A plasma reactor according to claim 7. The plurality of electrode panels are fixed by a fixing member on one end side or both end sides in one direction along the surface of the plurality of electrode panels.
The plasma reactor according to any one of claims 1-8. When viewed from the arrangement direction,
The shape of the gas flow path of the plurality of electrode panels is a strip shape,
The plasma reactor according to any one of claims 1-9. When viewed from the arrangement direction,
The shape of the gas flow path of the plurality of electrode panels is a square,
The plasma reactor according to any one of claims 1-10. When viewed from the arrangement direction,
wherein the gas flow paths of the plurality of electrode panels have curved perimeters;
The plasma reactor according to any one of claims 1-9. The dielectric is made of a material containing ceramic as a main component,
The plasma reactor according to any one of claims 1-12. The electrode is made of a material containing tungsten as a main component as a conductive material,
The plasma reactor according to any one of claims 1-13. The electrode part has a shape extending in the longitudinal direction, and the shape when the electrode part is cut perpendicular to the longitudinal direction is circular.
The plasma reactor according to any one of claims 1-14. The electrode section has a shape extending in the longitudinal direction, and the shape of the electrode section cut perpendicular to the longitudinal direction is a rhombus, and the opposing vertices of the rhombus are arranged along the flow path of the gas. ing,
The plasma reactor according to any one of claims 1-14. When viewed from the arrangement direction,
A plurality of the electrode portions having a shape extending in the longitudinal direction are provided, and the plurality of electrode portions are arranged at intervals in the lateral direction,
if there are multiple intervals, at least two intervals have different dimensions;
The plasma reactor according to any one of claims 1-16.

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