JP5046803B2 - Plasma generator, plasma generator, ozone generator, exhaust gas treatment device - Google Patents

Description

  The present invention relates to a plasma generator for generating plasma between a pair of electrodes sandwiching a space, and various apparatuses using the plasma generator.

  In fluids such as CO gas discharged from incomplete combustion of water heaters used in general households, exhaust gas from diesel engines, gasoline engines, or exhaust gas discharged from incinerators, PM such as CO and carbon, NOx Etc. are included. As a method for suppressing such emission of CO, PM, etc., a technique for purifying CO, PM, etc. using a plasma reaction has been proposed.

An apparatus for purifying a fluid by such a plasma reaction has a structure in which a pair of electrodes are opposed to each other by a certain distance. The purification by the plasma reaction is to purify the substance in the fluid by applying a high voltage between a pair of opposed electrodes to generate a plasma field and passing the fluid described above through the plasma field. is there. Note that each of the pair of electrodes is covered with an insulator, and both ends of the insulator are supported by the pair of side portions.
JP 2004-092589 A Japanese Patent Laid-Open No. 2005-093107 JP 2003-286829 A WO2004 / 072445 WO2005-000450 gazette WO2005-001250 publication

  However, if the fluid to be treated is hot, the device is rapidly heated to a hot state immediately after operation as the fluid passes. Alternatively, when the apparatus is operated, a large thermal stress is applied to the side portion of the apparatus due to heat generated from the electrodes. There is a concern that this thermal stress concentrates on the end portions of the inner wall surfaces of the insulating portion and the side portion forming the facing region, and cracks are generated in the apparatus starting from this concentrated portion. As a result, when the apparatus is broken, it is assumed that a plasma field is not generated favorably between the electrodes, and fluids such as PM, NOx, and CO that pass through the facing region cannot be purified well.

  The present invention has been devised in view of the above assumption, and its purpose is a structure that can reduce the possibility of breakage due to thermal stress caused by ambient atmosphere and heat during operation, and an apparatus using the structure. Is to provide.

  The plasma generator of the present invention includes a flat plate-like first electrode, a flat plate-like second electrode whose main surface is arranged to face the main surface of the first electrode, and the electrodes facing each other in plan view. A pair of side portions provided at both ends of the region and supporting the first electrode and the second electrode with a predetermined distance apart from each other, and a heater provided on the pair of side portions are provided.

  Preferably, the heater is electrically connected to the first electrode.

  Preferably, the heater is disposed between the first electrode and an external terminal electrically connected to the first electrode.

  Preferably, the heater connected to the first electrode is made of a material having a higher resistance value per unit length than the first electrode and having a volume resistivity higher than that of the first electrode. .

  Preferably, the heater connected to the first electrode has a resistance value per unit length higher than that of the first electrode and has substantially the same volume specific resistivity as that of the first electrode. Made of material.

  Preferably, the heater includes a first heater connected to the first electrode and a second heater connected to the second electrode, and the first heater includes the pair of sides. The second heater is disposed on one side of the pair, on the other side of the pair of side portions.

Also, preferably, in contact with the pair of side portions, and a first insulating portion for supporting the first electrode, and in contact with the pair of side portions, and further comprising a second insulating section for supporting the second electrode In addition, the first insulating portion, the second insulating portion, and the pair of side portions are made of the same material.

  The plasma generator of the present invention applies an AC voltage, a DC voltage, or a DC pulse voltage to the plasma generator of the present invention and the first electrode and the second electrode of the plasma generator, thereby the first generator. Voltage applying means for generating plasma is provided between the electrode and the second electrode.

  Preferably, the plasma is generated by applying the AC voltage, the DC voltage, or the DC pulse voltage between the first electrode and the second electrode, or before that, The flow of current to the heater is started.

  The ozone generator of the present invention is connected to the first flow path for allowing oxygen to flow into the opposed region of the plasma generator of the present invention, the first electrode of the plasma generator, and the second electrode. A voltage applying means connected to an external power source for applying an AC voltage, a DC voltage or a DC pulse voltage between these electrodes, and ozone discharged from the facing region of the plasma generator, And a second flow path that flows out of the region.

  The exhaust gas treatment apparatus of the present invention includes a first flow path for flowing exhaust gas from an internal combustion engine or an incinerator into the opposed region of the plasma generator of the present invention, the first electrode of the plasma generator, A voltage applying means connected to the second electrode and connected to an external power source for applying an AC voltage, a DC voltage or a DC pulse voltage between these electrodes, and discharged from the facing region of the plasma generator A second flow path for allowing the gas to be processed to flow out of the facing region.

  According to this invention, generation | occurrence | production of the big thermal stress which arises between the outer surface side of a side part and the inner surface side of the side part exposed to high temperature exhaust gas can be relieved.

  Hereinafter, an example of the plasma generator of the present invention will be described. Fig.1 (a) is a top view which shows an example of embodiment of the plasma generator of this invention. FIG.1 (b) is the side view seen from the A direction of Fig.1 (a). FIG. 2A is a cross-sectional view taken along line B-B ′ of FIG. FIG. 2B is a cross-sectional view taken along line C-C ′ of FIG. FIG. 2C is a cross-sectional view taken along line D-D ′ of FIG. In these figures, 1 is a plasma generator, 2 is a first electrode, 3 is a second electrode, 4 is a first insulating part, 5 is a second insulating part, 6 is a side part, 7 is a reaction channel, and 8 is a reaction channel. A heater 9 is an external terminal.

  The plasma generator 1 according to this example includes a flat plate-like first electrode 2 and a flat plate-like second electrode 3 whose main surface is disposed to face the main surface of the first electrode 2. . Further, it is provided with a pair of side portions 6 provided at both ends of the opposing regions of the electrodes 2 and 3 in plan view and supporting the first electrode 2 and the second electrode 3 with a predetermined distance apart. Furthermore, the heater 8 provided in a pair of side part 6 is provided.

  Further, the plasma generator 1 includes a first insulating part 4 that is a support that supports the first electrode 2, and a second insulating part 5 that is a support that supports the second electrode 3. Further, the pair of side portions 6 are provided on the outer peripheral portion rather than the first insulating portion 4 and the second insulator 5, and support the first insulating portion 4 and the second insulating portion 5, whereby the first electrode 2. A constant interval is formed between the first electrode 3 and the second electrode 3. The first insulating portion 4, the second insulating portion 5, and the pair of side portions 6 form a reaction flow path 7 serving as a region where a fluid flows.

For example, when the first insulating portion 4, the second insulating portion 5, and the side portion 6 are made of ceramics, an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, and a silicon carbide sintered body are used. It is made of an electrically insulating material such as cordierite. When the first insulating portion 4, the second insulating portion 5, and the side portion 6 are made of an aluminum oxide sintered body, first, alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcia (CaO), An appropriate organic solvent and a solvent are added to and mixed with a raw material powder such as magnesia (MgO) to produce a slurry. Next, this slurry-like material is formed into, for example, a sheet shape or a block shape by a conventionally known doctor blade method, calendar roll method, powder pressure molding method, injection molding method or the like, and is used for the plasma generator 1. A ceramic production form is obtained. These ceramic shaped bodies are then subjected to a suitable stamping process. At that time, a plurality of these ceramic production forms are laminated. Finally, the 1st insulating part 4, the 2nd insulating part 5, and the side part 6 are manufactured by baking at high temperature (about 1500-1800 degreeC). In this case, since these ceramic production | generation forms are integrally baked, the 1st insulating part 4, the 2nd insulating part 5, and the side part 6 will mutually be sintered.

  The first electrode 2 and the second electrode 3 are a pair of electrodes for generating a plasma field in the reaction flow path 7 located in the opposing region between these electrodes 2 and 3. The first electrode 2 and the second electrode 3 are formed on the surface or inside of the plasma generator 1, specifically, on the surface or inside of the first insulating part 4 or the second insulating part 5. The first electrode 2 and the second electrode 3 are disposed to face each other with a predetermined distance therebetween. The first electrode 2 and the second electrode 3 are electrically connected to an external terminal 9 (described later) formed on the outer surface of the plasma generator 1, for example, the outer surface of the side portion 6. The 1st electrode 2 and the 2nd electrode 3 are produced as follows. First, a conventionally known metallized paste containing a metal powder such as tungsten, molybdenum, copper, or silver is prepared. Then, using a printing means such as a screen printing method, the first electrode 2 and the second electrode 3 are arranged at predetermined positions to be the first insulating portion 4 or the second insulating portion 5 of the ceramic generating shape for the plasma generator 1. Apply metallized paste for Thereafter, the first electrode 2 and the second electrode 3 can be formed into a predetermined pattern of the plasma generator 1 by firing at the same time as these ceramic generating shapes.

  As shown in FIG. 2, the first electrode 2 and the second electrode 3 may be formed inside the first insulating portion 4 and the second insulating portion 5. This makes it difficult for the first electrode 2 and the second electrode 3 to directly contact, for example, an oxidizing fluid that passes through the reaction flow path 7. Therefore, the first electrode 2 and the second electrode 3 are not easily corroded by this fluid. Therefore, it is preferable because a decrease in the intensity of the plasma field can be suppressed. And when the 1st insulating part 4 and the 2nd insulating part 5 consist of cordierite, for example, the shortest distance from the surface of each insulating part 4 and 5 to the 1st electrode 2 or the 2nd electrode 3 is 100 micrometers or more. It is preferable to form in the position.

  Further, when the first electrode 2 and the second electrode 3 are formed to be exposed on the surfaces of the first insulating portion 4 and the second insulating portion 5, nickel or It is preferable to deposit a metal having excellent corrosion resistance such as gold. It is particularly preferable when the first electrode 2 and the second electrode 3 are directly exposed to an oxidizing fluid or the like.

  Further, a metal having excellent corrosion resistance such as nickel or gold may be deposited in a single layer. For example, when only a gold layer is deposited without forming a nickel layer, nickel does not diffuse to the surface of the gold layer along the grain boundary inside the gold layer due to heat. Therefore, variation in nickel diffusion from region to region is unlikely to occur, and variations in conductive characteristics in each region can be prevented. For this reason, when the plasma generator 1 is used in a high-temperature environment, only the gold layer is covered on the exposed surfaces of the first electrode 2 and the second electrode 3 by about 0.1 to 10 μm, for example, by plating. It is good to wear it.

  Further, the interval between the first electrode 2 and the second electrode 3 is 0.7 mm to 3.0 mm when oxygen is introduced to generate ozone, and fluid such as PM and oxidizing components in exhaust gas from a diesel engine is used. When it decomposes | disassembles by making it react, about 0.5 mm-2.0 mm is preferable. However, you may change with the intensity | strength of the required plasma field, the voltage applied to the 1st electrode 2 and the 2nd electrode 3, etc.

  Further, the external terminals 9 are formed on the outer surface of the plasma generator 1, for example, the outer surfaces of the pair of side portions 6. The external terminal 9 functions as a conductive path for applying a voltage from the external power source to the first electrode 2 and the second electrode 3. The external terminal 9 is electrically connected to each of the first electrode 2 and the second electrode 3. The external terminal 9 can be produced by the same method as the first electrode 2 and the second electrode 3. In addition, as in the case of the first electrode 2 and the second electrode 3, it is preferable to deposit a metal having excellent corrosion resistance such as nickel or gold on the exposed surface of the external terminal 9.

Then, the power supply terminal of the external power supply is electrically connected to the external terminal 9 by means such as pressure welding or bonding. By applying a voltage to the first electrode 2 and the second electrode 3 through the external terminal 9, the opposing region between the first electrode 2 and the second electrode 3 (the first electrode 2 and the second electrode 3 are seen in plan view). A plasma field can be generated in the overlapping region. Then, the fluid that passes through the reaction flow path 7 of the plasma generator is decomposed and purified by passing through the plasma field in the facing region between the first electrode 2 and the second electrode 3. For example, NO _X (nitrogen oxide) is decomposed by the following reactions (1) and (2), and N ₂ and O ₂ are generated and purified.

2NO ₂ → 2NO + O ₂ (1)
2NO + O ₂ → N ₂ + 2O ₂ (2)
In order to generate a plasma field between the first electrode 2 and the second electrode 3, for example, an alternating voltage having a high frequency is applied. The applied AC voltage is appropriately selected depending on the required intensity of the plasma field. For example, in a plasma generator that decomposes by reacting a fluid such as an oxidizing component such as PM in exhaust gas of a diesel engine, the applied AC voltage and its frequency are preferably 1 kV to 100 kV, 10 MHz to 100 MHz, for example.

  In the present invention, the heater 8 is provided on the pair of side portions 6. The heater 8 is electrically connected to an external power source, for example. Then, a current is passed through the heater 8 by this external power source to heat the pair of side portions 6, thereby heating by a high-temperature fluid passing through the reaction flow path 7 or heat generated by the first electrode 2 or the second electrode 3. The difference in thermal expansion between the first insulating portion 4 or the second insulating portion 5 and the side portion 6 can be reduced. Accordingly, the occurrence of cracks in the side portion 6 can be suppressed. Thereby, fluid, such as PM and an oxidizing component which passes through the inside of the reaction flow path 7, can be satisfactorily reacted and decomposed to be purified.

  Such a heater 8 is produced as follows, for example, when producing by baking a metallized paste. First, a metallized paste containing metal powder such as tungsten, molybdenum, copper, or silver is prepared. Then, using a printing means such as a screen printing method, a metallized paste for the heater 8 is applied to a predetermined position that becomes the side portion 6 of the ceramic generation form for the plasma generator 1. Thereafter, the heater 8 can be formed in a predetermined pattern on the pair of side portions 6 of the plasma generator 1 by firing simultaneously with the ceramic generating shape of the plasma generator 1.

  Alternatively, it may be formed by depositing a resistor material such as TaSiO or TiSiO on the outer surface of the side portion 6 of the plasma generator 1 by a conventionally known thin film forming technique such as sputtering or CVD. .

  Such a heater 8 preferably generates heat at about 100 to 300 ° C. in a plasma generator that decomposes by reacting a fluid such as an oxidizing component such as PM in exhaust gas from a diesel engine, for example.

  The heater 8 may be electrically connected to the first electrode 2 or the second electrode 3. Accordingly, the side portion 6 can be heated by causing a current to flow through the heater 8 substantially simultaneously with applying a voltage to the first electrode 2 and the second electrode 3 of the plasma generator 1.

  For example, the heater 8 is electrically connected to either the first electrode 2 or the second electrode 3 and is also electrically connected to an external terminal 9 for applying a voltage to the electrodes 2 and 3. May be. Accordingly, the first electrode 2 or the second electrode 3 and the external terminal 9 are electrically connected to the external terminal 9 connected to the first electrode 2 or the second electrode 3 separately from the heater 8. Therefore, it is not necessary to separately provide a connection electrode for this purpose, and the plasma generator 1 can be easily downsized.

  For example, a connection electrode that forms a parallel circuit together with the heater 8 may be provided separately between the first electrode 2 or the second electrode 3 and the external terminal 9.

Such a heater 8 has a higher resistance value per unit length than the first electrode 2 or the second electrode 3 connected to the heater 8 and is more specific to the volume than the first electrode 2 or the second electrode 3. What is necessary is just to form from a material with high resistivity. For example, a heater 8 molybdenum silicide _{[MoSi 2 (SiO 2, Al2O 3} ) ] and zirconia _{[ZrO 2 (Y 2 O 3,} CaO) ], the first electrode 2 or the second electrode 3 of molybdenum [Mo] or tungsten [ W].

  Alternatively, the heater 8 is obtained by adding more non-conductive powder such as glass or metal oxide to the metallized paste for the heater 8 than the metallized paste for the first electrode 2 or the second electrode 3. The electrical resistivity of the heater 8 may be higher than that of the first electrode 2 or the second electrode 3. The metallized paste for the heater 8 is preferably added with a material made of the same material as the pair of side portions 6. For example, when the pair of side portions 6 is made of an aluminum oxide sintered body, it is preferable to add aluminum oxide as the nonconductive powder added to the heater 8. Thereby, the interface connection strength between the heater 8 and the pair of side portions 6 can be improved.

  In addition, such a heater 8 can be effectively used, for example, when it is desired to increase the amount of heat generated by the heater 8, and the amount of generated heat can be greatly changed by the amount of non-conductive powder added. In addition, since the cross-sectional area of the first electrode 2 or the second electrode 3 and the cross-sectional area of the heater 8 can be made substantially the same, it is possible to make it difficult for the heater 8 to be disconnected.

  Alternatively, the heater 8 connected to the first electrode 2 or the second electrode 3 has a higher resistance value per unit length than the first electrode 2 or the second electrode 3, and the first electrode 2 or the second electrode. 3 may be made of a material having substantially the same volume resistivity as 3. In this case, the first electrode 2 or the second electrode 3 and the heater 8 can be made of the same material, and as a result, the thermal characteristics of the two can be made close. The effects on warpage, partial changes in physical properties, etc. are suppressed. In such a heater 8, for example, the sectional area of the heater 8 may be made smaller than the sectional area of the first electrode 2 or the second electrode 3. In order to make the sectional area of the heater 8 smaller than the sectional area of the first electrode 2 or the second electrode 3, for example, as shown in FIG. 3, the heater 8 is smaller than the first electrode 2 or the second electrode 3. What is necessary is just to make the thickness of the heater 8 smaller than the thickness of the 1st electrode 2 or the 2nd electrode 3 so that the resistance value per unit length may become high. As a method for manufacturing such a heater 8, when the metallized paste for the heater 8 is applied to the ceramic generating body for the plasma generator 1 by a screen printing method or the like, the thickness of the metallized paste for the heater 8 is set to the first electrode. 2 or the metallized paste for the second electrode 3 can be applied so as to be thinner, or the metallized paste for the heater 8 can be made thinner by applying pressure in the plane direction. .

  Further, the heater 8 may be arranged at a height position different from that of the first electrode 2 or the second electrode 3. For example, as shown in FIG. 4, it may be provided by a through conductor 8 a that becomes a part of the heater 8. The through conductors 8a can heat the pair of side portions 6 also in the height direction of the pair of side portions 6 (in FIG. 4, the side portions on both sides of the reaction channel 7).

  Such a through conductor 8a is manufactured as follows. That is, a through hole is formed in a region to be the side portion 6 of the ceramic generating shape for the plasma generator 1 by a punching means using a punching die. Next, the metallized paste for the through conductor 8a is filled into the through hole by printing means such as a screen printing method. Next, the through conductor 8a can be formed at a predetermined position to be the pair of side portions 6 of the plasma generator 1 by firing simultaneously with the ceramic generating shape for the plasma generator 1. The metallized paste for the through conductor 8a is manufactured in the same manner as the heater 8 described above, but is prepared to have a viscosity suitable for filling the through hole depending on the amount of the organic binder or organic solvent.

  The heater 8 includes a first heater connected to the first electrode 2 and a second heater connected to the second electrode 3, and the first heater is one side of the pair of side portions 6. In addition, the second heater may be disposed on the other side of the pair of side portions. Thus, each of the pair of side portions 6 can be heated by the heaters 8 arranged on each of the pair of side portions 6, and the occurrence of cracks in each of the pair of side portions 6 can be suppressed.

  Further, when the thickness of the heater 8 is made smaller than the thickness of the first electrode 2 or the second electrode 3, as shown in FIG. 5, at the connecting portion between the first electrode 2 or the second electrode 3 and the heater 8, These thicknesses may be changed gradually. Thereby, the difference of the emitted-heat amount which arises in the connection part of the 1st electrode 2 or the 2nd electrode 3, and the heater 8 becomes loose, and it can be made more excellent in heat resistance. In addition, since there is no steep step in the connection portion, the stress at the time of heat generation and thermal expansion is alleviated.

  Moreover, in order to make the cross-sectional area of the heater 8 smaller than the cross-sectional area of the first electrode 2 or the second electrode 3, the width of the heater 8 is set to the first electrode 2 connected to the heater 8 as shown in FIG. The thickness may be smaller than the width of the second electrode 3 or the width of the second electrode 3. In this case as well, the electrical resistance value per unit length can be increased.

  For example, when the metallized paste for the heater 8 is applied to the ceramic generating shape for the plasma generator 1 by a screen printing method or the like, the heater 8 has a width of the metallized paste for the heater 8 corresponding to the first electrode 2 or the second electrode. It can form by apply | coating so that it may become narrower than the width | variety of the metallizing paste for 2 electrodes 3. FIG.

  The first electrode 2 and the second electrode 3 are supported by the first insulating portion 4 and the second insulating portion 5, respectively, and the first insulating portion 4, the second insulating portion 5, and the pair of side portions 6. However, since they are made of the same material, it is difficult for differences in heat-related characteristics of these members to occur. That is, since the difference in thermal expansion coefficient between these members is small or the thermal expansion coefficient becomes substantially equal, it is possible to suppress the occurrence of thermal stress between these members, and the shape of the reaction channel 7 is caused by heat. Deformation can be suppressed.

  Further, as shown in FIG. 7, a plurality of reaction flow paths 7 may be stacked in parallel in the vertical direction. FIG. 7 is a sectional view showing an example of the embodiment of the plasma generator of the present invention. When a plurality of reaction flow paths 7 are stacked, the first electrode 2 and the second electrode 3 may be arranged in the vertical direction so as to alternately face each other. As a result, by generating a plasma field in each reaction channel 7, it is possible to react and decompose fluids such as PM and oxidizable components that pass through each reaction channel 7, so that the fluid can be efficiently used. Can be purified.

  Further, as shown in FIG. 8, the heaters 8 connected to the plurality of first electrodes 2, 2 ′, 2 ″ or the heaters connected to the plurality of second electrodes 3, 3 ′, 3 ″. You may connect 8 by the through-conductor 8a. The through conductors 8 a can heat the pair of side portions 6 in the thickness direction of the pair of side portions 6.

  Further, the through conductor 8a may be used as a part of the heater 8 as described above. Further, as shown in FIG. 9, after connecting the heaters 8 to the through conductors 8 a, one of the heaters 8 may be connected to the external terminal 9. Thereby, the total wiring length can be shortened, and the power supply voltage applied to the heater 8 can be lowered.

  In the above case, the through conductors 8a may be arranged in a plurality of rows between the heaters 8 formed at different height positions. In this case, the heat generation distribution of the side portion 6 can be appropriately dispersed, and the heat resistance can be further improved.

  The voltage applied between the first electrode 2 and the second electrode 3 may be a DC voltage. That is, it is possible to use a method of starting the heating of the heater 8 at the same time as the generation of the plasma field is started by applying a DC voltage to the first electrode 2 and the second electrode 3 of the plasma generator 1. For example, when the plasma generator is used for removing oxidizing components such as PM in exhaust gas from a diesel engine, the DC voltage applied is preferably 250 V or more, for example. In the case of a DC voltage, the power source can be reduced in size. For example, when the plasma generator 1 is mounted on an automobile, a larger current than that in the case of an AC voltage is applied to the first electrode 2 and the second electrode 3. Can be shed. Thereby, the plasma reaction in the reaction flow path 7 can be enhanced and the purification action can be enhanced.

  In addition, when a DC voltage is applied, the DC voltage may be a DC pulse voltage. For example, the pulse period may be 200 Hz to 1 KHz. As a result, it is possible to suppress the charged particles from constantly colliding with the electrode on one side by receiving the force of the electric field continuously.

  Next, the plasma generator of the present invention will be described. The plasma generator of the present invention uses the above-described plasma generator 1 as exemplarily shown in FIG. Further, a voltage application unit that is connected to the first electrode 3 and the second electrode 4 of the plasma generator 1 and applies an AC voltage, a DC voltage, or a DC pulse voltage between the first electrode 3 and the second electrode 4. 11 is provided. As a result, a plasma field can be generated in the facing region between the first electrode 3 and the second electrode 4.

  In addition, the plasma generator of the present invention can generate plasma by applying an AC voltage, a DC voltage, or a DC pulse voltage between the first electrode 2 and the second electrode 3 at the same time or earlier. In addition, the flow of current to the heater 8 may be started. Here, the charged particles generated by the plasma reaction are accelerated by the electric field. When an alternating voltage is applied, the acceleration direction of ions can be changed alternately depending on the frequency, so that the charged particles collide with only one side of the first electrode 2 or the second electrode 3 and the insulating member on one side or It can reduce that an electrode is worn more intensely compared with the other side, and can make the plasma generator 1 excellent in durability over a long period of time.

  In such a plasma generator, for example, when the heater 8 is not electrically connected to the first electrode 2 or the second electrode 3, the current is supplied to the heater 8 by an external power source or at the same time. After flowing, a voltage may be applied between the first electrode 2 and the second electrode 3.

  Further, when the heater 8 is electrically connected to the first electrode 2 or the second electrode 3, a voltage is applied between the first electrode 2 and the second electrode 3, and at the same time, a current is also applied to the heater 8. The flow and the side 6 will be heated. Further, in this case, the voltage applied between the first electrode 2 and the second electrode 3 is set so as not to generate a plasma field, and a current is passed through the heater 8 to heat the side portion 6 and then the applied voltage. May be increased to generate a plasma field between the first electrode 2 and the second electrode 3.

  Specifically, such a plasma generator can be used in, for example, an ozone generator that can satisfactorily change oxygen to ozone by a plasma reaction when the fluid is oxygen. For example, as shown in FIG. 12, such an ozone generator includes a first flow path 12 that allows oxygen to flow into a reaction flow path 7 that is a facing region of the plasma generator 1, and a plasma generator. A voltage applying means 11 connected to one first electrode 2 and the second electrode 3 and connected to an external power source for applying an AC voltage, a DC voltage or a DC pulse voltage between the electrodes 2 and 3; What is provided with the 2nd flow path which flows out the ozone discharged | emitted from the reaction flow path 7 located in the opposing area | region of the plasma generator 1 from the inside of the reaction flow path 7 located in an opposing area | region is mentioned.

  Alternatively, such a plasma generator is, for example, exhaust gas discharged from an internal combustion engine such as an engine used in automobiles, ships, generators, etc., or exhaust gas discharged from an incinerator, etc. This exhaust gas can be used in an exhaust gas treatment apparatus that can purify the exhaust gas well. Such an exhaust gas treatment apparatus includes, for example, a first flow path 12 for allowing exhaust gas from an internal combustion engine or an incinerator to flow into a reaction flow path 7 located in a region facing the plasma generator 1 described above, a plasma generator. A voltage applying means 11 connected to one first electrode 2 and the second electrode 3 and connected to an external power source for applying an AC voltage, a DC voltage or a DC pulse voltage between the electrodes 2 and 3; What has the 2nd flow path 12 which makes the to-be-processed gas discharged | emitted from the reaction flow path 7 located in the opposing area | region of a plasma generator flow out from the inside of the reaction flow path 7 located in an opposing area | region is mentioned. .

  Note that an exhaust gas purification mechanism other than the plasma generator 1 may be provided in the above-described exhaust gas treatment apparatus. For example, a filter or a catalyst may be attached before and after the plasma generator 1, thereby further reducing the discharge of fluid such as PM and oxidizing components in the exhaust gas. Examples of such a filter include a ceramic DPF (Diesel Particulate Filter) and the like, and platinum or the like can be used as a catalyst.

  In addition, such a plasma generator can be used in an air cleaning machine in which the fluid is air containing tobacco smoke, mold, dust, and the like, and the air can be purified well by a plasma reaction. Such an air cleaner includes, for example, at least a voltage applying means 11, optionally a first flow path 12, a second flow path 13 and the like, as described above.

  The present invention can be variously modified without departing from the gist of the present invention. For example, it may be used for applications other than the above-described embodiments and applied to a plasma generator, a plasma generator, and an apparatus using these.

  The present invention can be variously modified without departing from the gist of the present invention. For example, in the above description, purification of exhaust gas such as diesel engines used in automobiles, ships, generators, etc. has been described, but the present invention is applied to plasma generators and reaction devices used for other purposes. Also good. For example, the present invention can be applied to an air cleaning device used for deodorization, decomposition of dioxin, decomposition of pollen, plasma etching, a plasma generator and a reaction device mounted on a thin film device or the like. Further, the present invention can be applied to a plasma generator for reacting or decomposing a fluid passing through the reaction flow path 7 by a plasma reaction and its reaction apparatus.

  Further, as shown in FIG. 10, the heater 8 between the external terminal 9 and the first electrode 2 or the second electrode 3 is arranged in a snake shape so that the cross-sectional area of the heater 8 is narrowed. While increasing the heat generation, the path of the heater 8 may be lengthened to improve the heat generation of the side portion 6.

(A) is a top view which shows an example of embodiment of the plasma generator of this invention, (b) is the side view seen from the A direction of (a). 1A is a cross-sectional view taken along line BB ′ of the plasma generator of FIG. 1A, FIG. 1B is a cross-sectional view taken along line CC ′ of FIG. 1B, and FIG. It is sectional drawing in the DD 'line of 1 (b). It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is sectional drawing which shows an example of embodiment of the plasma generator of this invention. It is a perspective view which shows an example of the apparatus of this invention. It is a perspective view which shows an example of the apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plasma generator 2 ... 1st electrode 3 ... 2nd electrode 4 ... 1st insulation part 5 ... 2nd insulation part 6 ... Side part 7 ... Reaction flow path DESCRIPTION OF SYMBOLS 8 ... Heater 9 ... External terminal 10 ... Through-conductor 11 ... Voltage application part 12 ... 1st flow path 13 ... 2nd flow path

Claims (11)

A flat first electrode;
A plate-like second electrode, the main surface of which is arranged to face the main surface of the first electrode;
A pair of side portions that are provided at both ends of a facing region of these electrodes in a plan view and support the first electrode and the second electrode separated by a certain distance;
A plasma generator comprising: a heater provided on the pair of side portions. The plasma generator according to claim 1, wherein the heater is electrically connected to the first electrode.   The plasma generator according to claim 2, wherein the heater is disposed between the first electrode and an external terminal electrically connected to the first electrode.   The said heater connected to the said 1st electrode consists of material whose resistance value per unit length is higher than the said 1st electrode, and whose volume specific resistivity is higher than the said 1st electrode. Item 4. The plasma generator according to Item 3.   The heater connected to the first electrode is made of a material having a higher resistance value per unit length than the first electrode and made of a material having substantially the same volume resistivity as the first electrode. The plasma generator according to claim 3. The heater includes a first heater connected to the first electrode and a second heater connected to the second electrode,
6. The device according to claim 2, wherein the first heater is disposed on one side of the pair of side portions, and the second heater is disposed on the other side of the pair of side portions. The plasma generator described in 1. Contact with the pair of side, and the first insulating portion for supporting the first electrode, and in contact with the pair of side portions, with and further comprising a second insulating section for supporting the second electrode, the first The plasma generator according to any one of claims 1 to 6, wherein the insulating portion, the second insulating portion, and the pair of side portions are made of the same material. A plasma generator according to any one of claims 1 to 7,
Voltage application for generating plasma between the first electrode and the second electrode by applying an AC voltage or a DC voltage or a DC pulse voltage to the first electrode and the second electrode of the plasma generator And a plasma generator.   Applying the AC voltage, the DC voltage, or the DC pulse voltage between the first electrode and the second electrode, a current is supplied to the heater at the same time or before the plasma is generated. The plasma generator according to claim 8, wherein the flow is started. A first flow path for allowing oxygen to flow into the facing region of the plasma generator according to any one of claims 1 to 7,
Voltage application means connected to the first electrode and the second electrode of the plasma generator and connected to an external power source or an external power source for applying an AC voltage, a DC voltage or a DC pulse voltage between these electrodes; ,
The ozone generator provided with the 2nd flow path which makes the ozone discharged | emitted from the said opposing area | region of the said plasma generator flow out from the said opposing area | region. A first flow path for flowing exhaust gas from an internal combustion engine or an incinerator into the opposed region of the plasma generator according to any one of claims 1 to 7,
Voltage application means connected to the first electrode and the second electrode of the plasma generator, and connected to an external power source for applying an AC voltage, a DC voltage or a DC pulse voltage between the electrodes;
An exhaust gas treatment apparatus comprising: a second flow path for causing a gas to be treated discharged from the facing region of the plasma generator to flow out of the facing region.

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