JP6738175B2 - Plasma reactor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a plasma reactor, and more particularly to a plasma reactor suitable for an apparatus for purifying exhaust gas of an internal combustion engine (engine).

By passing the exhaust gas of an engine or the exhaust gas of an incinerator through a plasma field, CO (carbon monoxide), HC (hydrocarbon), NOx (nitrogen oxide) and PM (Particulate Matter: particulates) contained in the exhaust gas A plasma reactor for treating harmful substances such as substances is disclosed.

For example, by stacking a plurality of electrode panels on which discharge electrodes are formed and applying a voltage between adjacent electrode panels to generate low-temperature plasma (non-equilibrium plasma) due to dielectric barrier discharge, the electrodes flow between the electrode panels. Various plasma reactors that oxidize and remove PM in exhaust gas have been proposed (see, for example, Patent Documents 1 to 3). The plasma reactors described in Patent Documents 1 to 3 are equipped with an electric conduction portion for electrically connecting the discharge electrode and the power supply terminal. For example, the electrical conducting portion described in Patent Document 1 is composed of a lead line member, an electrode portion, and the like, and the lead line member and the electrode portion are connected via a spherical metal net or a spring member such as a spring. Further, the electrical conduction portion described in Patent Document 2 is a leaf spring that presses the connection portion extending from the discharge electrode. Further, Patent Document 3 discloses a technique in which an electric conduction portion is arranged with respect to a ridge formed on an end portion of an electrode panel.

Japanese Patent No. 3832654 (Fig. 1 etc.) Japanese Patent No. 4292629 (Fig. 1 etc.) Japanese Patent No. 4448095 (FIGS. 1 and 2)

By the way, in the prior art described in Patent Document 1, the above lead line members, which are electrical conducting portions, are arranged at both ends of the electrode panel. However, in order to secure sufficient reliability, it is necessary to increase the installation space of the lead line member to some extent, and thus it is difficult to downsize the plasma reactor. Further, also in the conventional techniques described in Patent Documents 2 and 3, since the electrical conducting portions are arranged at both ends of the electrode panel, it is necessary to secure a space for installing the electrical conducting portions at each end portion. Therefore, also in Patent Documents 2 and 3, it is difficult to downsize the plasma reactor.

The present invention has been made in view of the above problems, and an object thereof is to provide a plasma reactor that can be downsized while maintaining reliability.

As means (means 1) for solving the above-mentioned problems, it has a structure in which a plurality of electrode panels having discharge electrodes are laminated, and gas is caused to flow in a gas flow path formed between adjacent electrode panels to generate a voltage. A plasma reactor comprising a plasma panel laminate for generating plasma by applying a plurality of gas flow paths, each of which is directed in the same direction and is orthogonal to the laminating direction of the electrode panel. Is defined as the width direction of the gas flow path, the electrode panel has a thick portion including a ridge extending along the gas flow path, which is located at least apart in the width direction of the gas flow path. A plurality of electrical conducting portions having different electrical systems are provided in the thick portion arranged at the first end and the second end and arranged at the first end, and the electrical conducting portion is It is electrically connected to the discharge electrode, and the thick portion arranged at the first end portion is formed wider than the thick portion arranged at the second end portion. There is a plasma reactor.

Therefore, in the invention described in the above means 1, since all the electric conducting portions are provided in the thick portion arranged at the first end portion of the electrode panel, the second end portion in which the electric conducting portion is not provided is provided. It is possible to form the thick-walled portion arranged in the narrower than the thick-walled portion arranged in the first end portion. As a result, the size of the plasma reactor can be reduced in the width direction of the gas flow path flowing between the adjacent electrode panels. Further, the plasma reactor is miniaturized by forming the thick portion arranged at the second end portion to be narrow rather than narrowing the gas flow passage. As a result, even if the plasma reactor is downsized, the cross-sectional area of the gas flow passage is reliably ensured, so that the resistance in the gas flow passage is reduced and the pressure loss in the gas flow passage is suppressed. Therefore, the size of the plasma reactor can be reduced while maintaining the reliability of the plasma reactor.

Here, the “thickened portion arranged at the first end portion” means that the thickened portion is arranged such that the outer surface of the thickened portion matches the tip surface (side surface) of the first end portion of the electrode panel. Not only that, but also including arranging the thick portion so that the outer surface of the thick portion is located closer to the inner side (closer to the second end portion) than the tip surface of the first end portion. Similarly, the “thickened portion arranged at the second end” means that the thickened portion is arranged such that the outer surface of the thickened portion matches the tip surface (side surface) of the second end of the electrode panel. Not only that, but it also includes disposing the thick portion so that the outer surface of the thick portion is located inside (closer to the first end) than the tip surface of the second end portion.

The plasma panel laminate forming the plasma reactor has a structure in which a plurality of electrode panels having discharge electrodes are laminated. Examples of materials for forming the discharge electrode include tungsten (W), molybdenum (Mo), ruthenium oxide (RuO ₂ ), silver (Ag), copper (Cu), platinum (Pt), and the like.

The electrode panel has a pair of main surfaces located on opposite sides in the thickness direction, and the electrical conducting portion is a through-hole conductor that penetrates the thick portion arranged at the first end portion in the thickness direction. And a pad respectively formed on the pair of main surfaces and electrically connected to both ends of the through-hole conductor. With this configuration, when a plurality of electrode panels are stacked, the discharge electrode and the power source can be electrically connected via the electrically conductive portion.

Further, the thick portion arranged at the first end portion has an inner side surface facing the adjacent thick portion and an outer side surface located on the opposite side of the inner side surface in the width direction of the thick portion. It is preferable that the conducting portion is arranged closer to the outer side surface of the thick portion. With this configuration, by disposing the electrical conducting portion closer to the outer side surface of the thick portion, the insulating distance between the electrical conducting portion and the discharge electrode can be increased, so that the electrical conducting portion-discharge electrode It is possible to prevent the occurrence of discharge. Therefore, the reliability of the plasma reactor can be improved.

Further, the electrode panel is an elongated panel in which the length of the side extending along the passage direction of the gas flowing between the adjacent electrode panels is longer than the length of the side extending along the direction orthogonal to the passage direction. It is preferable that the plurality of electrical conducting portions are arranged at intervals along the passage direction. With this configuration, the insulation distance between the adjacent electrically conductive portions can be increased, so that the occurrence of discharge between the adjacent electrically conductive portions can be prevented. Therefore, the reliability of the plasma reactor is further improved.

The schematic sectional drawing which shows the plasma reactor in this embodiment. The top view which shows a plasma reactor. The perspective view which shows a plasma reactor. FIG. 3 is a perspective view showing a state where the plasma panel laminate is housed in a case. The perspective view which shows a plasma panel laminated body, a clamp, and a power supply terminal. The top view which shows a plasma panel laminated body, a clamp, and a power supply terminal. The schematic sectional drawing which shows a plasma panel laminated body and a clamp. The perspective view which shows an electrode panel. The perspective view which shows the electrode panel in other embodiment. FIG. 10 is a schematic cross-sectional view showing a plasma panel laminate and a clamp in another embodiment. The principal part perspective view which shows the electrode panel in other embodiment. In another embodiment, a perspective view showing a plasma panel layered product, a clamp, and a power supply terminal. The perspective view which shows the electrode panel in other embodiment. In other embodiment, a principal part sectional view showing a plasma panel layered product, a clamp, and a relay terminal.

Hereinafter, an embodiment in which the plasma reactor 1 of the present invention is embodied will be described in detail with reference to the drawings.

As shown in FIGS. 1 to 4, the plasma reactor 1 of the present embodiment is a device for removing PM contained in the exhaust gas of an automobile engine (not shown), and is attached to the exhaust pipe 2. .. The plasma reactor 1 includes a power supply 3, a case 10, and a plasma panel laminate 20.

The case 10 is formed in a rectangular tube shape using, for example, stainless steel. The first cone portion 11 is connected to the first end portion (the left end portion in FIG. 1) of the case 10, and the second cone portion 12 is connected to the second end portion (the right end portion in FIG. 1) of the case 10. There is. Further, the first cone portion 11 is connected to the upstream side portion 4 (engine side portion) of the exhaust pipe 2, and the second cone portion 12 is connected to the downstream side portion 5 of the exhaust pipe 2 (on the side opposite to the engine side). Part). Exhaust gas from the engine flows into the case 10 from the upstream side portion 4 of the exhaust pipe 2 via the first cone portion 11, passes through the case 10, and then passes through the second cone portion 12 to the exhaust pipe. 2 flows into the downstream portion 5.

As shown in FIG. 4, the plasma panel laminate 20 is housed in the case 10, and the mat 8 is interposed between the case 10 and the plasma panel laminate 20. The mat 8 has a function of fixing the plasma panel laminate 20 to the case 10. Here, as the material forming the mat 8, for example, an insulating material such as ceramic fiber, metal fiber, or foam metal can be used.

As shown in FIGS. 1 and 4 to 7, the plasma panel laminate 20 has a substantially rectangular parallelepiped shape having a pair of gas passage surfaces 21, 22 and four gas non-passage surfaces 23, 24, 25, 26. Is done. Both gas passage surfaces 21 and 22 are located on opposite sides of the plasma panel laminate 20. On the other hand, the gas non-passage surfaces 23 to 26 are located between the pair of gas passage surfaces 21 and 22.

Further, the plasma panel laminate 20 has a structure in which a plurality of electrode panels 30 and a pair of outer layer panels 50 located on the outer layer side of each electrode panel 30 are laminated. The panels 30 and 50 are arranged in parallel with the passage direction of the exhaust gas in the case 10 (the direction from the first cone portion 11 to the second cone portion 12) and have a gap (in the present embodiment, 0.5 mm). Gap). More specifically, the plasma panel laminate 20 has a gas flow path 27 through which exhaust gas passes between the adjacent electrode panels 30.

As shown in FIG. 1, the first wiring 6 and the second wiring 7 are electrically connected to each electrode panel 30 alternately along the thickness direction of the plasma panel laminate 20. The first wiring 6 is electrically connected to the first terminal of the power supply 3, and the second wiring 7 is electrically connected to the second terminal of the power supply 3.

As shown in FIGS. 1, 7, and 8, the electrode panel 30 of this embodiment has a pair of main surfaces (first main surface 31 and second main surface 32) located on opposite sides in the thickness direction. And has a substantially rectangular plate shape of 100 mm in length×120 mm in width×1 mm in thickness. In addition, in the electrode panel 30, the length of the side 33 (see FIG. 6) extending along the passage direction (lateral direction) of the exhaust gas flowing between the adjacent electrode panels 30 is in the direction (vertical direction) orthogonal to the passage direction. It is an elongated panel that is longer than the length of the side 34 (see FIG. 6) extending along the panel.

Further, the electrode panel 30 has a structure in which a discharge electrode 36 (thickness 10 μm) is built in a rectangular plate-shaped dielectric 35. In this embodiment, the dielectric 35 is made of ceramic such as alumina (Al ₂ O ₃ ) and the discharge electrode 36 is made of tungsten (W). The coefficient of thermal expansion of the dielectric 35 is about 2 to 8 ppm/°C, and in the present embodiment in which the dielectric 35 is made of alumina, it is about 8 ppm/°C. The coefficient of thermal expansion of the dielectric 35 is the average value of the measured values between room temperature and 400°C.

As shown in FIGS. 7 and 8, the electrode panel 30 has a first thick portion 92 at the first end 91 and a second thick portion 102 at the second end 101. The first thick portion 92 (first end portion 91) and the second thick portion 102 (second end portion 101) are arranged apart from each other in the width direction of the gas flow path 27, specifically, the gas flow. They are arranged on opposite sides of the path 27. In addition, the first thick portion 92 is configured to include a first ridge 93 extending along the gas passage 27, and the second thick portion 102 is also formed as a second protrusion extending along the gas passage 27. The ridge 103 is included. The ridges 93 and 103 of this embodiment project toward the second main surface 32 side and are integrated with the electrode panel 30. The area between the two protrusions 93, 103 is a recess 37 that opens at the second main surface 32. The recess 37 extends in the lateral direction of the electrode panel 30 and opens at both end surfaces of the electrode panel 30. Further, in the present embodiment, since the depth of the recess 37 is 0.5 mm, the thickness of the electrode panel 30 in the formation region of the recess 37 is 0.5 mm. Then, in the plasma panel laminate 20 of the present embodiment, the above-described gas flow path 27 is formed between the inner side surface of the recess 37 and the first main surface 31 of the electrode panel 30 adjacent to the lower layer side. It should be noted that the lowermost electrode panel 30 constituting the plasma panel laminate 20 does not have the recess 37 because the electrode panel 30 does not exist on the lower layer side.

As shown in FIG. 8, the first thick portion 92 arranged at the first end portion 91 has an inner side surface 94 facing an adjacent thick portion (here, the second thick portion 102) and a first thick portion 92. The thick portion 92 has an outer surface 95 located on the opposite side of the inner surface 94 in the width direction. The first thick portion 92 has a length of 120 mm×width of 15 mm×thickness of 1 mm, and the first protrusion 93 forming a part of the first thick portion 92 has a length of 120 mm×width of 15 mm. × The thickness is 0.5 mm. On the other hand, the second thick portion 102 arranged at the second end portion 101 also has an inner surface 104 facing the adjacent thick portion (here, the first thick portion 92) and a width of the second thick portion 102. And an outer side surface 105 located opposite to the inner side surface 104 in the direction. The second thick portion 102 has a length of 120 mm×width of 10 mm×thickness of 1 mm, and the second ridge 103 forming a part of the second thick portion 102 has a length of 120 mm×width of 10 mm×thickness. It is 0.5 mm. That is, the first thick portion 92 is formed wider than the second thick portion 102.

As shown in FIGS. 7 and 8, the first thick portion 92 is provided with a pair of electrical conducting portions 40 having different electrical systems. That is, the thick portion (first thick portion 92) provided with the electrical conducting portion 40 is formed wider than the thick portion (second thick portion 102) not provided with the electrical conducting portion 40. There is. The electric conducting portions 40 are arranged apart from each other along the passage direction of the exhaust gas flowing between the adjacent electrode panels 30, and are arranged near the outer surface 95 of the first thick portion 92. In addition, each electrical conduction portion 40 penetrates the first thick portion 92 in the thickness direction and is electrically connected to the discharge electrode 36. More specifically, each electrical conduction portion 40 includes a through hole conductor 41, a first pad 42 and a second pad 43. The through-hole conductor 41 penetrates the first thick portion 92 in the thickness direction. Then, in the predetermined electrode panel 30, the through-hole conductor 41 provided in the one electrical conduction portion 40 penetrates the extension portion 38 extending from the discharge electrode 36 to the outer peripheral side. Further, the first pad 42 is formed on the first main surface 31, and is electrically connected to the end portion of the through-hole conductor 41 on the first main surface 31 side. On the other hand, the second pad 43 is formed on the second main surface 32, and is electrically connected to the end portion of the through-hole conductor 41 on the second main surface 32 side. The first pad 42 and the second pad 43 each have a rectangular shape, and the surface thereof is plated with Ni or the like.

As shown in FIGS. 1 and 7, the outer layer panel 50 of the present embodiment has a pair of main surfaces (first main surface 51 and second main surface 52) located on opposite sides in the thickness direction. It has a substantially rectangular plate shape with a length of 100 mm and a width of 120 mm. The outer layer panel 50 has a thickness of 2 mm, which is thicker than the thickness (1 mm) of the electrode panel 30. It should be noted that the outer layer panel 50 of this embodiment is not formed with a recess similar to the recess 37.

The outer layer panel 50 is composed of a rectangular plate-shaped dielectric 53. In the present embodiment, the dielectric 53 is made of ceramic such as alumina. That is, the outer layer panel 50 of the present embodiment is made thicker than the electrode panel 30 using the same material as the electrode panel 30. Therefore, the mechanical strength of the outer layer panel 50 is higher than the mechanical strength of the electrode panel 30. The thermal expansion coefficient of the dielectric 53 is about 8 ppm/°C. The coefficient of thermal expansion of the dielectric 53 is the average value of the measured values between room temperature and 400°C.

As shown in FIG. 7, a pair of electrical conducting portions 60 having different electrical systems are provided on one side portion of the outer layer panel 50. The electrical conducting portions 60 are arranged apart from each other along the passage direction of the exhaust gas flowing between the adjacent outer layer panels 50. Further, each electric conduction portion 60 includes a through hole conductor 61, a first pad 62 and a second pad 63. The through-hole conductor 61 penetrates the outer layer panel 50 in the thickness direction. The first pad 62 is formed on the first main surface 51, and is electrically connected to the end portion of the through-hole conductor 61 on the first main surface 51 side. Then, the first pad 62 formed on the outer layer panel 50 on the lower layer side comes into contact with the second pad 43 formed on the electrode panel 30 on the lowermost layer. On the other hand, the second pad 63 is formed on the second main surface 52, and is electrically connected to the end portion of the through-hole conductor 61 on the second main surface 52 side. The second pad 63 formed on the outer layer panel 50 on the upper layer side comes into contact with the first pad 42 formed on the uppermost electrode panel 30. The first pad 62 and the second pad 63 each have a rectangular shape, and the surface thereof is plated with Ni or the like.

As shown in FIGS. 5 to 7, the plasma reactor 1 includes a pair of first clamps 71 for sandwiching and fixing each panel 30, 50 (plasma panel laminate 20) from the gas non-passing surface 24 side, and each panel. A pair of second clamps 72 are provided to sandwich and fix 30, 50 from the gas non-passing surface 26 side. Each of the clamps 71 and 72 is formed by bending a metal plate (for example, a stainless plate made of a material such as SUS430). Each first clamp 71 has a function of sandwiching the panels 30 and 50 in the stacking direction and a function of electrically connecting to the discharge electrode 36. On the other hand, each second clamp 72 has only the function of sandwiching the panels 30 and 50 in the stacking direction.

In addition, each clamp 71, 72 includes a plate member 73 and a pressing plate 74. The plate member 73 extends in the stacking direction of the panels 30 and 50. The pressing plate 74 is formed integrally with the plate member 73, and is arranged at both ends of the plate member 73. Each pressing plate 74 has elasticity and is a leaf spring having a folded structure. Further, each pressing plate 74 presses the surface of the outer layer panel 50 (specifically, the first main surface 51 of the upper outer layer panel 50 or the second main surface 52 of the lower outer layer panel 50). ing. Further, each pressing plate 74 has a first pad 62 formed on the first main surface 51 of the outer layer panel 50 on the upper layer side or a second pad formed on the second main surface 52 of the outer layer panel 50 on the lower layer side. It is pressed against 63.

As shown in FIGS. 2 to 6, the plasma reactor 1 includes a pair of power supply terminals 81. The power supply terminal 81 of this embodiment has the same structure as the spark plug. More specifically, the power supply terminal 81 includes an external connection portion, a conductive seal containing metal powder, an insulator, a metal shell, talc, packings, and the like. The external connection portion is connected to the central shaft 82 via a conductive seal. One end of the central shaft 82 is arranged inside the insulator. Note that the power supply terminal is not limited to that of this embodiment, and may have another structure as long as it has a structure in which the insulator and the case 10 are insulated from each other by the insulator. ..

In addition, each power supply terminal 81 has a base end (center shaft 82) electrically connected to the center of the plate member 73 of the first clamp 71, and a tip end exposed from the case 10. The power supply terminals 81 project in the same direction. In the present embodiment, the tip of one of the power supply terminals 81 is connected to the first wiring 6 (see FIG. 1) and a power supply different from the wiring 81 connected to the first wiring 6 is provided. The tips of the terminals 81 are connected to the second wiring 7 (see FIG. 1).

As shown in FIG. 1, the plasma reactor 1 of the present embodiment is used, for example, to remove PM contained in exhaust gas. In this case, when a pulse voltage (for example, peak voltage: 5 kV (5000 V), pulse repetition frequency: 100 Hz) is applied between the power source 3 and the adjacent electrode panel 30, a dielectric barrier discharge occurs and a discharge electrode 36 is discharged. Plasma is generated by the dielectric barrier discharge. Then, due to the generation of plasma, PM contained in the exhaust gas flowing through the gas passage 27 is oxidized (combusted) and removed.

Next, a method for manufacturing the plasma reactor 1 will be described.

First, a ceramic material containing alumina powder as a main component is used to form first to third ceramic green sheets to be the dielectric 35. As a method for forming the ceramic green sheet, a well-known forming method such as tape forming or extrusion forming can be used. Then, laser processing is performed on each ceramic green sheet to form a through hole for the through hole conductor 41. The through holes may be formed by punching, drilling, or the like.

Next, by using a conventionally known paste printing device (not shown), the through holes for the through-hole conductors 41 are filled with a conductive paste (tungsten paste in the present embodiment), and the through-hole conductors 41 are not fired. Forming a through-hole conductor portion of.

Next, the first ceramic green sheet is placed on a support (not shown). Further, a conductive paste is printed on the back surface of the first ceramic green sheet using a paste printer. As a result, an unfired electrode having a thickness of 10 μm to be the discharge electrode 36 is formed on the back surface of the first ceramic green sheet. A known printing method such as screen printing can be used as a method for printing the unfired electrodes on the first ceramic green sheet.

After the conductive paste is dried, the second ceramic green sheet and the third ceramic green sheet are sequentially laminated on the back surface of the first ceramic sheet on which the unfired electrodes are printed, and the sheet is laminated in the sheet laminating direction. Apply pressure. As a result, the ceramic green sheets are integrated to form a ceramic laminated body. Further, using a paste printer, a conductive paste is printed on the main surface of the first ceramic green sheet to form the unfired first pad 42, and at the same time, the conductive paste is formed on the back surface of the third ceramic green sheet. Printing a conductive paste to form unfired second pads 43. Note that the third ceramic green sheet is laminated after being subjected to punching processing that matches the shape of the recess 37.

Further, a ceramic green sheet to be the dielectric 53 is formed by the same method as the method to form the first to third ceramic green sheets to be the dielectric 35. Then, laser processing is performed on the ceramic green sheet to form a through hole for the through hole conductor 61. Next, using a paste printer, the through holes for the through-hole conductors 61 are filled with a conductive paste to form unfired through-hole conductor portions that will become the through-hole conductors 61.

Next, the ceramic green sheet is placed on the support base. Further, using a paste printing device, a conductive paste is printed on the main surface of the ceramic green sheet to form the unfired first pad 62, and a conductive paste is printed on the back surface of the ceramic green sheet, The unfired second pad 63 is formed.

Next, after performing a drying step and a degreasing step according to a known method, the ceramic green sheet and the unfired electrode are heated to a predetermined temperature (for example, about 1400°C to 1600°C) at which alumina and tungsten can be sintered. Simultaneous firing is performed. As a result, alumina in the ceramic green sheet and tungsten in the conductive paste are simultaneously sintered, and the dielectrics 35 and 53, the discharge electrode 36, the through-hole conductors 41 and 61, the first pads 42 and 62, and the second pad 42 and 62. The pads 43 and 63 are formed by simultaneous firing, and the ceramic green sheets become the panels 30 and 50.

Then, a laminating step is performed to laminate a plurality of the obtained panels 30 and 50 to form a plasma panel laminate 20. Next, using the clamps 71 and 72, the plurality of electrode panels 30 and the pair of outer layer panels 50 are sandwiched and fixed in the stacking direction. At this time, the pair of pressing plates 74 forming the clamps 71 and 72 are pressed against the first pad 62 of the outer layer panel 50 on the upper layer side and the second pad 63 of the outer layer panel 50 on the lower layer side. Further, by welding or the like, the central shaft 82 of the power supply terminal 81 is electrically connected to the central portion of the plate member 73 forming the first clamp 71. Next, after the mat 8 is attached so as to cover the outer surface of the plasma panel laminate 20, the case 10 is attached so as to cover the outer surface of the mat 8. After that, the first wiring 6 is connected to the tip of one power supply terminal 81, and the second wiring is connected to the tip of the power supply terminal 81 different from the power supply terminal 81 connected to the first wiring 6. Connect 7. The plasma reactor 1 is completed through the above processes.

Therefore, according to this embodiment, the following effects can be obtained.

(1) In the plasma reactor 1 of the present embodiment, all the electrical conducting portions 40 are provided in the first thick portion 92 arranged at the first end portion 91 of the electrode panel 30, so that the electrical conducting portion 40 is The second thick portion 102 arranged at the second end portion 101 not provided can be formed narrower than the first thick portion 92 arranged at the first end portion 91. As a result, the size of the plasma reactor 1 can be reduced in the width direction of the gas flow path 27 flowing between the adjacent electrode panels 30. Further, instead of narrowing the gas flow path 27, the second thick portion 102 arranged at the second end portion 101 is formed narrow, so that the plasma reactor 1 is downsized. As a result, even if the plasma reactor 1 is downsized, the cross-sectional area of the gas flow passage 27 is reliably ensured, the resistance in the gas flow passage 27 is reduced, and the pressure loss in the gas flow passage 27 is suppressed. .. Therefore, the size of the plasma reactor 1 can be reduced while maintaining the reliability of the plasma reactor 1.

(2) When the clamps 71, 72 of the present embodiment are used, stress concentration occurs in the panel (outer layer panel 50) located in the outermost layer of the plasma panel laminate 20, so that the outer layer panel 50 is easily cracked. .. This is because the pressing plates 74 of the clamps 71 and 72 are pressed against the outer layer panel 50 in a state close to what is called “point contact”.

Therefore, in the present embodiment, by making the thickness of the outer layer panel 50 thicker than the thickness of the electrode panel 30, the mechanical strength of the outer layer panel 50 with which the clamps 71 and 72 are in contact is determined by the electrode with which the clamps 71 and 72 are not in contact. It is higher than the mechanical strength of the panel 30. As a result, by strengthening the force with which the panels 71 and 72 are sandwiched by the clamps 71 and 72, even if stress concentration occurs in the outer layer panel 50, the occurrence of cracks or the like in the outer layer panel 50 is suppressed. Therefore, the reliability of the plasma reactor 1 can be improved.

(3) The plasma reactor 1 of this embodiment is attached to the exhaust pipe 2 via the first cone portion 11 and the second cone portion 12. As a result, the resistance in the exhaust gas flow passage in which the exhaust gas flows decreases in the order of the upstream side portion 4 of the exhaust pipe 2 →the first cone portion 11 →the plasma reactor 1 →the second cone portion 12 →the downstream side portion 5 of the exhaust pipe 2. Therefore, the pressure loss in the exhaust gas passage can be suppressed. As a result, it is possible to prevent a decrease in engine output due to pressure loss.

The above embodiment may be modified as follows.

The electrode panel 30 of the above-described embodiment has the first thick portion 92 provided with the electrical conducting portion 40 at the first end portion 91 and the second thick portion 102 not provided with the electrical conducting portion 40. It had on the second end 101. However, as shown in the electrode panel 111 of FIG. 9, a thick portion 113 not provided with the electrical conducting portion 112 is further provided between the first end portion 114 and the second end portion 115 (in the middle in FIG. 9). It may be arranged at. Further, the thick portion 113 may be arranged at a plurality of positions between the first end portion 114 and the second end portion 115. The first thick portion 116 arranged at the first end 114 is preferably formed wider than all the other thick portions 113 and 117. Further, the thick portion arranged between the first end 114 and the second end 115 may be composed of a plurality of protrusions arranged along the gas flow path.

In the plasma panel laminate 20 of the above embodiment, the protrusions 93 and 103 are integrated with the electrode panel 30. However, as shown in the plasma panel laminate 121 of FIG. 10, the ridges 122 may be separate from the electrode panel 123. The ridge 122 and the electrode panel 123 may be joined via a pad 124 or the like.

-In the electrode panel 30 of the said embodiment, the protrusions 93 and 103 protruded to the 2nd main surface 32 side. However, the protrusions 93 and 103 may project to the first main surface 31 side, or may project to both the first main surface 31 side and the second main surface 32 side.

The electric conduction part 40 of the above embodiment has a structure including the through-hole conductor 41, the first pad 42, and the second pad 43, but the structure of the electric conduction part may be changed. For example, as shown in FIG. 11, the electrical conduction portion 131 may be composed of so-called end face through holes 132, first pads 133 and second pads 134. The end face through hole 132 is formed by applying a tungsten paste to the inner wall surface of the recess 137 formed on the outer surface 136 of the thick portion 135 and then firing the paste. The first pad 133 is electrically connected to the end of the end surface through hole 132 on the first main surface 138 side, and the second pad 134 is on the end of the end surface through hole 132 on the second main surface 139 side. Are electrically connected to each other. Further, of the pair of electrical conducting portions 131 included in the electrode panel 140, the first pad 133 that constitutes one electrical conducting portion 131 is electrically connected to the extending portion 143 of the discharge electrode 142 via the via conductor 141. Has been done. The surfaces of the pads 133, 134 and the end through holes 132 are preferably plated with Ni or the like in order to suppress the oxidation of tungsten.

The clamps 71, 72 in the above-described embodiment are configured by integrally forming the pressing plates 74 on both ends of the plate member 73, but the structure of the clamps may be changed. For example, as shown in FIG. 12, the clamp 151 may be configured by attaching plate springs 153 to both ends of the shaft member 152. The shaft member 152 is inserted into a hole 155 (see FIG. 13) that penetrates the plasma panel laminate 154. The leaf springs 153 are fixed to both ends of the shaft member 152. Both ends of each leaf spring 153 are bent to the back surface side of the leaf spring 153, and the first pad 158 (see FIG. 13) formed on the first main surface 157 of the uppermost electrode panel 156, or It is pressed against the second pad 160 (see FIG. 13) formed on the second main surface 159 of the lowermost electrode panel 156. It should be noted that the fixing ring 161 is press-fitted into the distal end portion of the shaft member 152 in a state where the shaft member 152 is inserted through the leaf spring 153. Further, the plasma reactor includes two relay terminals 162. Each relay terminal 162 is electrically connected to two clamps 151 of the four clamps 151, and is also electrically connected to a pair of power supply terminals 163. The relay terminal 162 has a flat plate shape, the shaft member 152 is inserted into the base end portion, and the center shaft 164 of the power supply terminal 163 is connected to the tip end portion. The base end of the relay terminal 162 is sandwiched by the leaf spring 153 and the fixing ring 161.

Further, as shown in FIG. 14, the clamp 171 may include a pressing plate 172 and a compression coil spring 173. The pressing plate 172 is in contact with the surface 175 of the electrode panel 174. Further, the compression coil spring 173 is interposed between the relay terminal 176 arranged on the pressing plate 172 and the fixing ring 178 provided on the end portion of the shaft member 177 to connect the pressing plate 172 and the relay terminal 176 to the electrode panel. It is adapted to press on the surface 175 side of 174.

The plasma panel laminate 20 of the above embodiment has a structure in which a plurality of electrode panels 30 and a pair of outer layer panels 50 are laminated. However, the plasma panel laminate may be a laminate that does not have the pair of outer layer panels 50.

The electrode panel 30 of the above embodiment is configured by incorporating the discharge electrode 36 in the dielectric 35. However, the electrode panel may be formed by forming the discharge electrode 36 on the surface of the dielectric 35.

The plasma reactor 1 of the above-described embodiment has been used for purifying exhaust gas of an engine of a vehicle, but may be used for purifying exhaust gas of an engine of a ship, for example. Further, the plasma reactor 1 may be one that performs plasma processing, does not need to process exhaust gas, and may not be used for purification.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiment will be listed below.

(1) The plasma reactor according to the above-mentioned means 1, wherein the protrusion is integrated with the electrode panel.

(2) The plasma reactor according to the above-mentioned means 1, wherein the protrusion is separate from the electrode panel.

(3) In the above-mentioned means 1, the thick portion provided with the electrical conducting portion is formed wider than the thick portion not provided with the electrical conducting portion. ..

(4) The plasma reactor according to the above means 1, wherein the thick portion arranged at the first end portion is formed wider than all other thick portions.

(5) In the above means 1, the electrode panel has a pair of main surfaces located on opposite sides in the thickness direction, and the ridges project to at least one of the main surfaces. And a plasma reactor.

(6) In the above means 1, the electrode panel has a pair of main surfaces located on opposite sides in the thickness direction, and the electrical conducting portion is the thick portion arranged at the first end portion. And a pad formed on each of the pair of main surfaces and electrically connected to both ends of the through-hole conductor. ..

DESCRIPTION OF SYMBOLS 1... Plasma reactor 20, 121, 154... Plasma panel laminated body 27... Gas flow paths 30, 111, 123, 140, 156, 174... Electrode panel 33... Side 34 extending along the passage direction of gas... Gas passage direction Sides 36, 142 extending along a direction orthogonal to the discharge electrodes 40, 112, 131... Electrically conductive portions 91, 114... First end portions 92, 116, 135... First thick portion 93 as thick portion... First ridge 94 as a ridge... Inner side surface 95, 136... Outer side surface 101, 115... Second end portion 102, 117... Second thick portion 103 as a thick portion... Second ridge as a ridge 113... Thick part 122... Ridge

Claims (3)

A plasma panel laminate having a structure in which a plurality of electrode panels having discharge electrodes are laminated, and a plasma is generated by flowing a gas through a gas flow path formed between adjacent electrode panels to apply a voltage A plasma reactor,
The gas flow path is a plurality, all facing the same direction,
When the direction orthogonal to the stacking direction of the electrode panel is defined as the width direction of the gas flow channel, the electrode panel includes at least the thick portion including a ridge extending along the gas flow channel, at least the gas flow. Having a first end and a second end that are located apart in the width direction of the road,
The thick portion arranged at the first end is provided with a plurality of electric conducting portions having different electric systems,
The electrically conductive portion is electrically connected to the discharge electrode,
The plasma reactor characterized in that the thick portion arranged at the first end portion is formed wider than the thick portion arranged at the second end portion. The thick portion arranged at the first end portion has an inner surface facing the adjacent thick portion and an outer surface located on the opposite side of the inner surface in the width direction of the thick portion. Then
The said electrical conduction part is formed so that it may extend along the lamination direction of the said electrode panel in the position near the said outer side surface except the said outer side surface of the said thick part. Plasma reactor. The electrode panel is an elongated panel in which the length of the side extending along the passage direction of the gas flowing between the adjacent electrode panels is longer than the length of the side extending along the direction orthogonal to the passage direction. Yes,
The plasma reactor according to claim 1 or 2, wherein the plurality of electrical conducting portions are arranged apart from each other along the passing direction.

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