JP2009087700A - Plasma generator, method for manufacturing plasma generator, and reaction apparatus - Google Patents

Abstract

A plasma generator capable of suppressing a temperature rise in a discharge space in a central portion is provided.
A plurality of dielectrics arranged in one direction and a conductor disposed inside each of the dielectrics, and applying a voltage between the conductors allows the dielectrics to be applied. 3 is a plasma generator capable of generating plasma in a discharge space between three conductors, and the number of dielectrics 3 is four or more, and between the conductors 5 facing each other across the discharge space at the center in the arrangement direction of the dielectrics 3 The facing area is smaller than the facing area between the conductors 5 facing each other across the discharge space at the end in the arrangement direction of the dielectrics 3.
[Selection] Figure 3

Description

  The present invention relates to a plasma generator for purifying a fluid with generated plasma, a method for manufacturing the same, and a reaction apparatus using the plasma generator.

  Conventionally, a method using plasma is known as a method for purifying a fluid containing harmful substances such as exhaust gas. Such plasma is generated by applying a voltage between the conductors, reacts with harmful substances of the fluid passing between the conductors, and can purify the fluid.

By disposing such a conductor inside the dielectric, it is possible to generate plasma by silent discharge without directly exposing the conductor to the plasma. In such a plasma generator, the discharge space surrounded by the dielectric is arranged in a predetermined direction, and the conductor is arranged so as to sandwich the discharge space.
Japanese Patent Laying-Open No. 2004-92589 (paragraph 0030, FIG. 7)

  In general, when plasma is generated in the discharge space, the temperature in and near the discharge space rises due to the plasma. However, in the plasma generator in which the discharge spaces are arranged in a certain direction, there is a problem that the temperature tends to rise because the heat in the discharge space in the central part is less likely to escape than the discharge space in the end part.

  The present invention has been made to solve the above problems, and provides a plasma generator capable of suppressing a temperature rise in the discharge space in the central portion, a method for manufacturing the same, and a reaction apparatus using the plasma generator. The purpose is to do.

  The plasma generator of the present invention has a plurality of dielectrics arranged in one direction and a conductor disposed inside each dielectric, and a voltage is applied between the conductors. A plasma generator capable of generating plasma in a discharge space between the dielectrics, wherein the number of the dielectrics is four or more, and sandwiches the discharge space at the center in the arrangement direction of the dielectrics The opposing area between the opposing conductors is smaller than the opposing area between the opposing conductors across the discharge space at the end in the arrangement direction. Hereinafter, this plasma generator is referred to as a “first plasma generator”.

  Preferably, in the first plasma generator, when there are an even number of the dielectrics, the facing area between the conductors facing each other across the discharge space at the center in the arrangement direction of the dielectrics Is smaller than the facing area between the conductors facing each other across the discharge space at the end in the arrangement direction. Hereinafter, this plasma generator is referred to as a “second plasma generator”.

  Preferably, in the first plasma generator, when there are an odd number of the dielectrics, the first plasma generators face each other across one of the two adjacent discharge spaces in the central portion of the dielectric in the arrangement direction. The facing area between one set of the conductors or the facing area between two sets of the conductors facing each other across the two discharge spaces is the discharge space at the end in the arrangement direction. It is smaller than the facing area between the conductors facing each other with a gap in between. Hereinafter, this plasma generator is referred to as a “third plasma generator”.

  Preferably, in the third plasma generator, a first conductor disposed in the middle of the dielectric in the arrangement direction of the dielectric, and a second conductor adjacent to the first conductor. The facing area between the body and the body is smaller than the facing area between the second conductors facing each other across the first conductor. Hereinafter, this plasma generator is referred to as a “fourth plasma generator”.

  Preferably, in the second plasma generator, at least one of the two conductors facing each other across the discharge space at the center in the arrangement direction of the dielectrics, when viewed in plan, Of the two conductors has a through hole inside the outer edge of the other conductor. Hereinafter, this plasma generator is referred to as a “fifth plasma generator”.

  Preferably, in the third plasma generator, at least one of the three conductors facing each other across the two discharge spaces adjacent to each other in the central portion of the dielectric in the arrangement direction. Has a through hole inside the outer edge of the conductor adjacent to the at least one of the three conductors. Hereinafter, this plasma generator is referred to as a “sixth plasma generator”.

  Preferably, in the second plasma generator, at least one of the two conductors facing each other across the central discharge space penetrates to a position corresponding to a central portion of the central discharge space. Has holes. Hereinafter, this plasma generator is referred to as a “seventh plasma generator”.

  Preferably, in the third plasma generator, at least one of the three conductors facing each other across the two adjacent discharge spaces is at least adjacent to the two discharge spaces. A through hole is provided at a position corresponding to the center of one discharge space. Hereinafter, this plasma generator is referred to as an “eighth plasma generator”.

  Preferably, in any one of the first to eighth plasma generators, the facing area between the conductors gradually decreases from the end in the arrangement direction of the dielectric toward the center. Hereinafter, this plasma generator is referred to as a “ninth plasma generator”.

  In the method for manufacturing a plasma generator according to the present invention, in any one of the first to ninth plasma generators, the dielectric and the conductor disposed inside the dielectric are formed of a plurality of ceramics. It forms by baking simultaneously the conductive paste arrange | positioned between a green sheet and this ceramic green sheet.

  The reaction apparatus of the present invention supplies a fluid between a power source for applying an AC voltage or a pulse voltage between the conductors of any of the first to ninth plasma generators, and the dielectric. Possible supply part.

  The plasma generator of the present invention has a plurality of dielectrics arranged in one direction and a conductor disposed inside each dielectric, and a dielectric is formed by applying a voltage between the conductors. A plasma generator capable of generating plasma in a discharge space between the electrodes, wherein there are four or more dielectrics, and an opposing area between conductors facing each other across a discharge space at a central portion in the arrangement direction of the dielectrics, Since it is smaller than the facing area between the conductors facing each other across the discharge space at the end in the arrangement direction, the temperature rise in the discharge space at the center in the arrangement direction of the dielectric can be suppressed.

  In the method for producing a plasma generator according to the present invention, a dielectric and a conductor disposed inside the dielectric are simultaneously fired with a plurality of ceramic green sheets and a conductive paste disposed between the ceramic green sheets. Since it forms by this, the plasma generator which can suppress the temperature rise in the discharge space of a center part can be manufactured easily.

  The reaction apparatus of the present invention includes a power source for applying an AC voltage, a rectangular wave voltage, a square wave voltage, or a pulse voltage between conductors of a plasma generator, and a supply unit capable of supplying a fluid between dielectrics. Thus, a reactor operating stably can be realized by using a plasma generator that can suppress a temperature rise in the discharge space at the center.

  Hereinafter, embodiments of the plasma generator of the present invention will be described in detail.

(First embodiment)
FIG. 1 is a perspective view showing a configuration example of a plasma generator according to the first embodiment of the present invention. FIG. 2 (a) is a plan view of the plasma generator of FIG. 1, and FIG. FIG. 2 is a side view of the plasma generator of FIG. 1. 3A is a cross-sectional view taken along the line AA ′ in FIG. 2A, FIG. 3B is a cross-sectional view taken along the line BB ′ in FIG. 2B, and FIG. ) Is a cross-sectional view taken along the line CC ′ of FIG. As shown in FIGS. 1 to 3, the plasma generator 1 according to the present embodiment includes a base 2. The base 2 includes a plurality of plate-like dielectrics 3 arranged in one direction, and a support portion 4 that supports the plurality of dielectrics 3 at a predetermined interval. The dielectric 3 and the support part 4 constitute a cavity 6 serving as a discharge space. Furthermore, a conductor 5 capable of generating plasma in the cavity 6 is disposed inside the dielectric 3. The conductors 5 are arranged so as to face each other with the cavity 6 interposed therebetween, and the first conductors 5a that face each other with the center cavity 6 in the arrangement direction of the dielectrics 3 interposed therebetween, and the dielectric at the end in the arrangement direction. 3 and a second conductor 5b disposed in the interior of the housing. Furthermore, an external terminal 7a is provided on one end face of the base 2, and an external terminal 7b is provided on the other end face opposite to the end face provided with the external terminal 7a. As shown in FIG. 3, the plurality of conductors 5 are alternately connected to the external terminals 7a and the external terminals 7b. In the present specification, the substrate 2 refers to a portion excluding other components such as the conductor 5 formed therein, and the plasma generator 2 includes a laminate of a plurality of ceramic green sheets and a structure thereof as described later. When the conductive paste formed on the surface of each ceramic green sheet is obtained by simultaneous firing, only the laminate is referred to.

  In the plasma generator 1 according to the present embodiment, a high voltage is applied between the adjacent conductors 5 to generate plasma in the cavity 6, and by passing a fluid such as exhaust gas through the cavity 6, It reacts and decomposes chemicals in the fluid.

The base 2 is made of an electrically insulating material, for example, ceramic. Specifically, when the substrate 2 is manufactured, a ceramic green sheet is prepared, and then the prepared ceramic green sheet is appropriately punched, and a plurality of sheets are laminated as necessary, so that a high temperature (about 1300 to 1800) is obtained. Manufactured by baking at a temperature of ° C. An example of the electrical insulating material is an aluminum oxide sintered body (alumina ceramic). For example, a green sheet made of an aluminum oxide sintered body is prepared by adding an appropriate organic solvent and solvent to raw material powders such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcia (CaO), and magnesia (MgO). The mixture is mixed to obtain a slurry, and this is obtained by employing a conventionally known doctor blade method, calendar roll method, or the like and molding it into a sheet shape.

  When producing a laminate of ceramic green sheets, the ceramic green sheets are laminated and then subjected to pressure bonding. The pressure bonding is performed by applying a pressure of about 3.0 to 8.0 MPa, and heating is performed at 35 to 80 ° C. as necessary. At this time, in order to form the cavity 6, a through hole is formed in at least one green sheet. Moreover, in order to obtain sufficient adhesiveness between the ceramic green sheets, an adhesive prepared by mixing a solvent and a resin binder may be used. In addition to the aluminum oxide sintered body, examples of the dielectric material include a mullite sintered body, an aluminum nitride sintered body, a cordierite sintered body, and a silicon carbide sintered body.

  The first conductor 5 a and the second conductor 5 b are held in the base 2 and function as conductors for generating plasma in the cavity 6. That is, the first conductor 5a and the second conductor 5b are formed on the surface or inside of the base 2 so as to face each other with the cavity 6 in between. Note that the end portions of the first conductor 5a and the second conductor 5b are led out to the vicinity of the outer surface of the base 2, and are electrically connected to the external terminals 7a and 7b directly or via an auxiliary conductor. Is done. The first conductor 5a and the second conductor 5b are made of a metal powder conductor such as tungsten, molybdenum, copper, or silver, and a predetermined ceramic green sheet for the substrate 2 is used by printing means such as a screen printing method. The conductor paste for the first conductor 5a and the second conductor 5b is printed and applied at the position of, and simultaneously fired with the ceramic green sheet for the substrate 2, thereby forming a predetermined pattern in the substrate 2. it can. The conductive paste is mixed and kneaded by kneading means such as a ball mill, a three-roll mill, or a planetary mixer, with an organic binder and an organic solvent, and if necessary, a dispersant added to the main component metal powder. Produced. Glass or ceramic powder may be added to the conductor paste in accordance with the sintering behavior of the ceramic green sheet or to increase the bonding strength with the insulating substrate after sintering.

  As shown in FIG. 3, the first conductor 5 a and the second conductor 5 b are preferably disposed inside the base 2 without being exposed to the cavity 6. This is because the first conductor 5a and the second conductor 5b are not easily brought into direct contact with the fluid passing through the cavity 6, so that the first conductor 5a and the second conductor 5b are corroded by the fluid, and the plasma strength is increased. It is because it can suppress that falls. In addition, when forming on the surface of the base | substrate 2, it is preferable to adhere the metal which is excellent in corrosion resistance, such as nickel and gold | metal | money, to the exposed surface of the 1st conductor 5a and the 2nd conductor 5b. . In addition, when the plasma generator 1 is used in an environment at a high temperature, the metal is easily diffused by heat. Therefore, a metal having excellent corrosion resistance such as nickel or gold is deposited in a single layer. It does not matter. For example, when a nickel plating layer and a gold plating layer are sequentially deposited, nickel and gold are easily diffused by heat at a high temperature, and the first conductor 5a and the second conductor 5b are deteriorated to cause plasma. There is a possibility that the intensity of the plasma will decrease and the intensity of the plasma may vary. For this reason, when the plasma generator 1 is used in a high-temperature environment, only the gold plating layer is deposited on the exposed surfaces of the first conductor 5a and the second conductor 5b by about 0.1 to 10 μm. It does not matter.

In addition, the areas of the first conductor 5a and the second conductor 5b are appropriately determined depending on the required plasma intensity, the voltage applied between the conductors 5, and the like. For example, the area of the first conductor 5a and the second conductor 5b of the plasma generator 1 for purifying a fluid, such as PM or oxidizing components in the exhaust gas of diesel ^engines, 100 mm 2 ～90000Mm ² is preferably about.

  In the plasma generator 1 according to the present embodiment, the facing area between the first conductors 5a facing each other across the central cavity 6 in the arrangement direction of the dielectrics 3 is an end portion in the arrangement direction of the dielectrics 3 Is smaller than the facing area between the first conductor 5a and the second conductor 5b facing each other with the cavity 6 therebetween. As a result, the amount of plasma generated between the first conductors 5a is smaller than the amount of plasma generated between the first conductors 5a and the second conductors 5b. The intensity is smaller than the plasma intensity between the first conductor 5a and the second conductor 5b.

  External terminals 7 a and 7 b are attached to the outer surface of the base 2. The external terminals 7 a and 7 b function as a conductive path for applying a voltage to the conductor 5 from an external power source, and are electrically connected to each of the conductors 5 led to the outer surface of the base 2. The external terminals 7a and 7b are made of a metal powder conductor such as tungsten, molybdenum, copper, or silver, and the external terminals 7a are placed at predetermined positions on the ceramic green sheet for the substrate 2 using printing means such as a screen printing method. 7b can be formed at a predetermined position of the plasma generator 1 by printing and applying a conductor paste for 7b and co-firing with a ceramic green sheet for the substrate 2. The conductor paste for the external terminals 7a and 7b is produced in the same manner as the conductor paste for the first conductor 5a and the second conductor 5b, but has a viscosity suitable for printing depending on the amount of the organic binder and the organic solvent. To be prepared.

  In addition, it is preferable to deposit a metal having excellent corrosion resistance such as nickel or gold on the exposed surfaces of the external terminals 7a and 7b. In addition, in order to prevent the external terminals 7a and 7b from being oxidatively corroded and to strengthen the connection between the external terminals 7a and 7b and the power supply terminal of the external power supply, a nickel plating layer having a thickness of about 1 to 10 μm. And a gold plating layer having a thickness of about 0.1 to 3 μm are preferably sequentially deposited. In the same manner as described above, the external terminals 7a and 7b may be coated with a single layer of metal having excellent corrosion resistance, such as nickel or gold, when used at a high temperature.

  Alternatively, the external terminals 7a and 7b may be metal plates attached at predetermined positions after firing the ceramic green sheet for the substrate 2.

Then, the power supply terminal of the external power supply is electrically connected to the external terminals 7a and 7b by means such as pressure contact or bonding, and when a voltage is applied to the first conductor 5a and the second conductor 5b through the external terminals 7a and 7b, Opposing surfaces of the first conductor 5a and the second conductor 5b and the first conductor 5a and the first conductor 5a (in a plan view, a region where the first conductor 5a and the second conductor 5b overlap and Plasma can be generated between the first conductor 5a and a region where the first conductor 5a overlaps. As a result, the fluid passing through the cavity 6 passes through the plasma between the first conductor 5a and the second conductor 5b and between the first conductor 5a and the first conductor 5a. Disassembled and purified. For example, NO _X (nitrogen oxide) is decomposed by the reactions shown in the following formulas (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 plasma between the first conductor 5a and the second conductor 5b and between the first conductor 5a and the first conductor 5a, an alternating voltage having a high frequency is applied. The AC voltage to be applied is appropriately selected depending on the required plasma intensity and the like. For example, the frequency of the alternating voltage applied in the plasma generator for purifying fluids such as PM and oxidation components in the exhaust gas of a diesel engine is, for example, 10 kHz to 100 MHz.

  Further, the voltage applied between the conductors 5 may be a pulse voltage in addition to the AC voltage. The AC voltage is not limited to a sine wave voltage, and may be a rectangular wave voltage or a square wave voltage.

  The plasma generator 1 according to the present embodiment is a plasma generator having a base 2 having a cavity 6 serving as a discharge space inside, and the intensity of the plasma is different from that of the first conductor 5a and the second conductor 5b. It is appropriately selected depending on the area. Here, the opposing area between the first conductors 5a facing each other across the central cavity 6 in the arrangement direction of the dielectrics 3 is the same as that of the first conductors 5a facing each other across the cavity 6 at the end in the arrangement direction. It is smaller than the facing area between the second conductor 5b. Therefore, the plasma intensity in the cavity 6 sandwiched between the first conductors 5a is smaller than the plasma intensity in the cavity 6 sandwiched between the first conductors 5a and the second conductors 5b. Thereby, when a voltage is applied to the plasma generator 1 to generate plasma, the temperature rise of the discharge space in the central portion of the plasma generator 1 can be reduced.

  In the plasma generator 1 according to the present embodiment, the cavity 6 has a shape extending in one direction. However, the shape is not limited to this and may be an arbitrary shape.

  Further, in the plasma generator 1 according to the present embodiment, the base body 2 is composed of a plurality of ceramic layers, and through holes are provided in the ceramic layers to form the cavities 6. It may well be constituted by a hole having one opening on the surface of the ceramic layer.

  As shown in FIG. 4, the plasma generator may have a plurality of cavities 6 </ b> A to 6 </ b> D formed in the thickness direction. In the plasma generator 11 of FIG. 4, the first conductor 5 a is disposed inside the dielectric 3 disposed so as to sandwich the cavities 6 </ b> B and 6 </ b> C, and the second conductor 5 b is disposed inside the other dielectric 3. Is arranged. Here, the facing area between the first conductors 5a is smaller than the facing area between the first conductors 5a and the second conductors 5b.

  In such a configuration, a voltage is applied between the adjacent conductors 5 to generate plasma in each of the cavities 6A to 6D, and the fluid passing through the cavities 6A to 6D is reacted and decomposed. The fluid can be purified.

  According to the above configuration, when the plasma is generated by applying a voltage to the plasma generator 11, the intensity of the plasma in the discharge space in the central portion of the plasma generator 11 is reduced. The temperature rise in the discharge space at can be reduced.

  Further, as described above, by providing the plurality of cavities 6A to 6D in the plasma generator 11, the fluid can be reacted and decomposed in the plurality of cavities 6A to 6D, so that the fluid can be purified efficiently. .

  In the plasma generator 11 of FIG. 4, the first conductor 5a is disposed inside the dielectric 3 that sandwiches the cavities 6B and 6C. However, in the dielectric 3 between the cavities 6B and 6C. The first conductor 5 a may be disposed, and the second conductor 5 b may be disposed inside the other dielectric 3. Even in such a case, since the facing area between the conductors 5 sandwiching the cavities 6B and 6C becomes small, the intensity of the plasma generated in the cavities 6B and 6C becomes small.

  Here, the discharge space at the center of the plasma generator in this specification refers to the discharge space at the center in the arrangement direction of the dielectric, and when the plasma generator has an odd number of discharge spaces, When the plasma generator has an even number of discharge spaces, it is at least one of the two adjacent discharge spaces at the center of the dielectric arrangement direction.

  In the plasma generator according to the present embodiment, in order to reduce the intensity of the plasma in the discharge space in the central portion of the plasma generator, between the conductors 5 facing each other across the discharge space in the central portion. The facing area is made smaller than the facing area between the conductors 5 facing each other across the discharge space at the end.

  That is, when there are an even number of dielectrics, the opposing area between the opposing conductors across the central discharge space in the arrangement direction of the dielectrics is defined as the opposing conductivity across the discharge space at the end in the arrangement direction. When there is an odd number of dielectrics between the opposing areas between the bodies, between a pair of conductors facing each other across one of two adjacent discharge spaces in the center of the dielectric arrangement direction Or the facing area between two sets of conductors facing each other across the two discharge spaces is made smaller than the facing area between the facing conductors across the discharge space at the end in the arrangement direction.

  The discharge space at the end in the dielectric arrangement direction is a discharge space at both ends in the dielectric arrangement direction.

  Further, the opposing area between the conductors facing each other across the discharge space other than the central discharge space and the end discharge space in the arrangement direction of the dielectric is the distance between the opposing conductors across the central discharge space. (Hereinafter, referred to as “between the conductors in the central part”) may be equal to or larger than the opposing area between the conductors in the central part. The facing area may gradually decrease toward the portion. As described above, when the opposing area between the conductors gradually decreases from the end in the arrangement direction of the dielectric toward the center, the intensity of the plasma gradually increases from the end of the plasma generator toward the center. Since the intensity of the plasma does not change suddenly between adjacent discharge spaces, and the temperature does not change rapidly between adjacent discharge spaces, it is generated in the dielectric. The stress to be reduced is more convenient.

  Further, in the plasma generator according to the present embodiment, all the conductors are rectangular. However, if the opposing area between the central conductors can be made smaller than the opposing area between the end conductors, each conductor The shape of each conductor and the arrangement of each conductor inside the dielectric are arbitrary.

  For example, when there are an even number of dielectrics, when at least one of two conductors facing each other across the central discharge space in the direction of arrangement of the dielectrics when viewed in plan, the two conductors You may have a through-hole inside the outer edge of the other conductor. In this case, referring to FIG. 3, one of the two first conductors 5a has a through hole inside the outer edge of the other first conductor 5a, or each of the two first conductors 5a. However, both have a through hole inside the outer edge of the other first conductor 5a.

  In addition, when there are an odd number of dielectrics, at least one of the three conductors facing each other with two adjacent discharge spaces sandwiched in the central portion in the arrangement direction of the dielectrics is the three dielectrics. A through hole may be provided in the inner region of the outer edge of at least one adjacent conductor. In this case, referring to FIG. 4, the central first conductor 5a of the three first conductors 5a has a through hole in the inner region of at least one outer edge of the two adjacent first conductors 5a. Alternatively, the first conductor 5a at the end of the three first conductors 5a has a through hole in the inner region of the outer edge of the central first conductor 5a.

  Moreover, when providing a through-hole in a conductor as mentioned above, it is preferable to provide a through-hole in the position corresponding to the center part of one discharge space adjacent to the conductor. In this way, if a through hole is provided at a corresponding position in the central portion of the discharge space, unlike the end portion of the discharge space, there is no heat escape, and plasma is generated in the central portion of the discharge space where the temperature rise is particularly large. Since it does not generate | occur | produce, the temperature rise of the discharge space in the center part of a plasma generator can be reduced more.

  In addition, by providing a plurality of through holes in the conductor so that the conductor has a shape such as a lattice shape, stress generated due to a difference in thermal expansion coefficient between the conductor and the substrate can be reduced.

  The plasma generators 1 and 11 are formed by simultaneously firing the ceramic green sheet on the substrate 2, and the first conductor 5a, the second conductor 5b, and the external terminals 7a and 7b are made of a conductor paste. It is preferably formed by firing at the same time as the ceramic green sheet. As a result, the plasma generator is integrated by simultaneously firing ceramics and a conductive paste. Therefore, even when the plasma generator is used for a long period of time under high temperature, high vibration, etc., the plasma generator is not deformed. It can be made small and the shape of the cavity 6 can be made stable. Therefore, fluids such as PM and oxidizing components that pass through the cavity 6 can be stably reacted over a long period of time, decomposed, and favorably purified.

  Instead of the plasma generator alone, another exhaust gas purification mechanism may be used together. For example, a filter or a catalyst may be attached before and after the plasma generator, which can further reduce the emission of PM, oxidizing components, etc. 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.

(Second Embodiment)
FIG. 5 is a conceptual diagram showing a structural configuration of the reaction apparatus 100 according to the second embodiment of the present invention. In addition, about the structure similar to 1st Embodiment, the same code | symbol as 1st Embodiment is attached | subjected and description is abbreviate | omitted.

  The reaction apparatus 100 includes the plasma generator 1 of the first embodiment, and is configured as an apparatus that processes and discharges a fluid to be processed by the plasma generator 1. The fluid to be treated is, for example, exhaust gas from an internal combustion engine of an automobile, and NOx is decomposed by a chemical change in the cavity 6 (hereinafter also referred to as “discharge space”). Further, for example, the fluid to be treated is chlorofluorocarbon used as a cooling medium in a refrigerator or an air conditioner, and chlorofluorocarbon is decomposed by a chemical change in the discharge space 6. In the following description, a portion of the reaction apparatus 100 other than the plasma generator 1 may be referred to as a reaction apparatus main body 101.

  The reactor main body 101 is processed by a fluid source 103 that supplies a fluid to be processed, a supply pipe 105 (an example of a supply unit) that guides the fluid to be processed from the fluid source 103 to the plasma generator 1, and the plasma generator 1. A discharge pipe 107 for discharging the treated fluid, a treated fluid pump 109 for controlling the flow of the treated fluid, a coolant source 111 for supplying a cooling medium, and cooling from the coolant source 111 to the plasma generator 1 A supply flow pipe 50A (an example of a cooling unit) that guides the medium, a discharge flow pipe 50B that guides the cooling medium from the plasma generator 1 to the refrigerant source 111, and a cooling medium pump 113 that controls the flow of the cooling medium. (An example of a cooling unit).

  The fluid source 103 generates a fluid to be processed such as an internal combustion engine of an automobile that discharges exhaust gas as the fluid to be processed. Alternatively, the fluid source 103 holds a fluid to be processed such as a tank that holds a cooling medium of a used refrigerator or an air conditioner.

  One end side of the supply tube 105 communicates with a space for generating or holding the fluid to be processed of the fluid source 103, and the other end side communicates with the discharge space 6 of the plasma generator 1. The plasma generator 1 side of the supply tube 105 corresponds to the number of discharge spaces 6 and is referred to as a first branch portion 105aA, a second branch portion 105aB, and a third branch portion 105aC (hereinafter simply referred to as “branch portion 105a”. The first branch portion 105aA to the third branch portion 105aC communicate with the first discharge space 6A to the third discharge space 6C, respectively.

  One end side of the discharge tube 107 communicates with the discharge space 6 of the plasma generator 1 from the side opposite to the supply tube 105, and the other end side is opened to the atmosphere, or holds the processed fluid after processing. It communicates with a space (not shown) for performing another process on the fluid to be processed later. The plasma generator 1 side of the discharge tube 107 corresponds to the number of discharge spaces 3 and is referred to as a first branch portion 107aA, a second branch portion 107aB, and a third branch portion 107aC (hereinafter simply referred to as “branch portion 107a”. The first branch portion 107aA to the third branch portion 107aC communicate with the first discharge space 6A to the third discharge space 6C, respectively. Note that the discharge pipe 107 may be omitted. For example, the treated fluid after treatment may be directly discharged from the discharge space 6 to the atmosphere.

  The supply pipe 105 and the discharge pipe 107 are formed of an appropriate material such as metal or resin. The supply pipe 105 and the discharge pipe 107 may or may not have flexibility. For example, the branch portion 105a and the branch portion 107a are connected to the discharge space 6 by bringing the end of the branch portion 105a or the branch portion 107a into contact with the side surface of the substrate 2 that does not have the opening of the discharge space 6. The branching portion 105a or the branching portion 107a and the base body 2 are fixed by an appropriate fixing member such as an adhesive or a screwing member. The branch portion 105a and the branch portion 107a are fitted and inserted into the discharge space 6, and a protruding annular portion such as an outflow connection tube is formed integrally with the base 2 at the end portion of the discharge space 6, and the protruding portion. May be performed by fitting and inserting into the branch part 105a or the branch part 107a.

  The fluid pump 109 to be processed is provided in at least one of the supply pipe 105 and the discharge pipe 107. FIG. 5 illustrates a case where the supply pipe 105 is provided. When the fluid to be processed is caused to flow by the power of the fluid source 103, such as when the fluid source 103 is an internal combustion engine, the pump for fluid to be processed 109 may be omitted. Further, the pump 109 for fluid to be processed can be provided in the plasma generator 1. The fluid pump 109 to be processed may be constituted by an appropriate pump such as a rotary pump or a reciprocating pump.

  The refrigerant source 111 includes, for example, a heat exchanger, and lowers the temperature of the cooling medium from the discharge flow pipe 50B by the heat exchanger and supplies it to the supply flow pipe 50A. Note that the coolant source 111 need only be able to supply a cooling medium, and may not receive the cooling medium from the discharge flow pipe 50B and circulate the cooling medium. That is, the cooling medium from the discharge flow pipe 50 </ b> B may be discharged to a location different from the refrigerant source 111. For example, when tap water is used as the cooling medium, the water from the discharge flow pipe 50 </ b> B may be discharged to a location different from the water source as the refrigerant source 111. Conversely, when the cooling medium is circulated, the refrigerant source 111 may be omitted.

  One end of the supply flow pipe 50A communicates with the refrigerant source 111, and the other end communicates with the cavity 6 (flow path) of the plasma generator 1 via the inflow connection pipe and the like as described above. . One end of the discharge flow pipe 50 </ b> B communicates with the cavity 6 of the plasma generator 1 through an outflow connection pipe or the like provided integrally with the base 2, and the other end communicates with the refrigerant source 111. . The flow tube 50 is formed of an appropriate material such as metal or resin. The flow tube 50 may or may not have flexibility.

  The cooling medium pump 113 is provided in at least one of the supply flow pipe 50A and the discharge flow pipe 50B. FIG. 5 illustrates a case where the supply flow pipe 50A is provided. Note that the cooling medium pump 113 is omitted when the coolant source 111 is a tank in a high position and power for flowing the cooling medium appropriately can be obtained, for example, the cooling medium can flow by gravity. Also good. The cooling medium pump 113 can also be provided in the plasma generator 1. The cooling medium pump 113 may be configured by an appropriate pump such as a rotary pump or a reciprocating pump.

  FIG. 6 is a block diagram showing the configuration of the electrical system of the reaction apparatus 100. Here, as an example, a temperature detection element 115 for detecting the temperature of the base 2 and a heater 116 for heating the base 2 are provided inside the base 2. Further, a conductor terminal 117 for applying a voltage to the conductor 5 on the surface of the substrate 2, a sensor terminal 118 for outputting an electric signal from the temperature detection element 115, and a heater for supplying electric power to the heater 116. Assume that the terminals 119 are exposed.

  The reactor main body 101 includes a conductor terminal 117, a sensor terminal 118, a device-side conductor terminal 141 connected to the heater terminal 119, a device-side sensor terminal 143, and a device-side heater terminal 145. Yes. The plasma generator 1 is driven and controlled by power supplied from the reactor main body 101 through these terminals. Specifically, it is as follows.

  The power supply unit 121 is configured to include, for example, a battery, and converts DC power from the battery into AC power or DC power having an appropriate voltage for supply. Alternatively, AC power having a commercial frequency is converted into AC power or DC power having an appropriate voltage and supplied. The power of the power supply unit 121 is supplied to the control unit 123, the discharge control unit 125, the temperature detection unit 127, the heater driving unit 129, the fluid pump 109 to be processed, and the cooling medium pump 113.

  The discharge control unit 125 converts the power supplied from the power supply unit 121 into AC power having a voltage corresponding to the control signal from the control unit 123, and converts the converted power into the device-side conductor terminal 141 and the conductor. It is supplied to the conductor 5 through the terminal 117 for use. For example, the discharge control unit 125 includes a power supply circuit such as an inverter or a transformer. In the conductor 5, an amount of discharge corresponding to the voltage applied by the discharge control unit 125 is performed.

  For example, when the temperature detection element 115 is configured by a resistor whose resistance value changes due to a temperature change, the temperature detection unit 127 converts the power supplied from the power supply unit 121 into DC power or AC power of an appropriate voltage. Then, the converted electric power is supplied to the temperature detection element 115 via the device-side sensor terminal 143 and the sensor terminal 118. Then, the temperature detection element 115 detects the resistance value of the temperature detection element 115 and outputs a signal corresponding to the detected resistance value to the control unit 123. The temperature detection element 115 may calculate the temperature of the temperature detection element 115 based on the detected resistance value and output a signal corresponding to the calculated value to the control unit 123.

  The heater drive unit 129 converts the power supplied from the power supply unit 121 into DC power or AC power having a voltage corresponding to a control signal from the control unit 123, and converts the converted power into the device-side heater conductor 145 and The heat is supplied to the heater 116 via the heater conductor 119. The heater driving unit 129 includes a power supply circuit such as a rectifier circuit or a transformer, for example. The heater 116 generates heat in an amount corresponding to the voltage applied by the heater driving unit 129.

  Each of the fluid pump 109 and the cooling medium pump 113 includes, for example, a motor as a pump drive source and a motor driver that drives the motor, although not particularly illustrated. The electric power supplied from the power supply unit 121 is converted into AC power or DC power having a voltage corresponding to a control signal from the control unit 123 and applied to the motor. The motor rotates at the number of rotations corresponding to the applied voltage, and consequently a force corresponding to the applied voltage is applied to the fluid to be processed and the cooling medium.

  The input unit 131 receives a user operation and outputs a signal corresponding to the user operation to the control unit 123. For example, the input unit 131 receives a drive start operation, a drive stop operation, various temperature setting operations related to temperature setting and flow rate control of the reaction apparatus 100, and outputs a signal corresponding to the operation. The input unit 131 includes, for example, a control panel including various switches and a keyboard.

  For example, although not particularly illustrated, the control unit 123 is configured by a computer including a CPU, a ROM, a RAM, and an external storage device. The control unit 123 outputs control signals to the discharge control unit 125, the heater driving unit 129, the fluid to be processed pump 109, and the cooling medium pump 113 based on signals from the temperature detection unit 127 and the input unit 131.

  For example, when a signal corresponding to a driving start operation of the reaction apparatus 100 is input from the input unit 131, the control unit 123 controls the discharge control unit 125 to start supplying power to the conductor 5. Is output from the input unit 131 and a control signal is output to the discharge control unit 125 so as to stop the supply of power to the conductor 5. .

  For example, the control unit 123 determines that the temperature detected by the temperature detection unit 127 has not reached a predetermined target temperature set as a temperature at which the plasma generator 1 can efficiently generate plasma. In such a case, when the plasma generator 1 reaches the target temperature, a control signal is output to the discharge controller 125 so that the power supplied to the conductor 5 is increased more than the power supplied during normal operation. Then, a control signal is output to the discharge control unit 125 so that the power supplied to the conductor 5 is maintained at the power supplied during normal operation.

  For example, the control unit 123 determines that the temperature detected by the temperature detection unit 127 has not reached a predetermined target temperature set as a temperature at which the plasma generator 1 can efficiently generate plasma. In this case, a control signal is output to the heater driving unit 129 so that power is supplied to the heater 116 or power supplied to the heater 116 is increased. When the plasma generator 1 reaches the target temperature, a control signal is output to the heater drive unit 129 so that the power supplied to the heater 116 is reduced or the supply of power to the heater 116 is stopped. To do.

  In addition, for example, the control unit 123 may detect the temperature detected by the temperature detection unit 127 and the temperature at which the plasma generator 1 can efficiently generate plasma, or the plasma generator 1 and the reaction device main body 101. Compared with a predetermined target temperature set as a safe operating temperature, if the detected temperature is higher than the target temperature, the flow rate of the cooling medium is increased, and if it is lower, the flow rate of the cooling medium is decreased In this manner, a control signal is output to the cooling medium pump 113.

  For example, the control unit 123 determines that the temperature detected by the temperature detection unit 127 has not reached a predetermined target temperature set as a temperature at which the plasma generator 1 can efficiently generate plasma. In this case, when it is determined that the flow rate of the fluid to be processed is low and reached, a control signal is output to the pump 109 for fluid to be processed so as to increase the flow velocity of the fluid to be processed.

  Further, for example, the control unit 123 compares the temperature detected by the temperature detection unit 127 with a predetermined temperature range set as a temperature at which the plasma generator 1 or the reaction device main body unit 101 is safely operated, When the detected temperature exceeds the set temperature range, a control signal is output so as to notify the occurrence of abnormality to a notifying unit such as a display device or a speaker (not shown).

  According to the second embodiment described above, the reactor 100 generates plasma in the plasma generator 1 of the first embodiment, the supply pipe 105 that supplies the fluid to be treated to the discharge space 3, and the discharge space 3. And a discharge pipe 107 for discharging the reaction fluid obtained by chemically changing the fluid to be treated. As in the first embodiment, the durability of the plasma generator 1 can be improved and the plasma generator 1 can be improved. As a result, the durability of the reactor 100 can be improved and the size reduction effect can be obtained.

  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. However, the present invention is applied to plasma generators and their reaction devices used for other purposes. May be. For example, the present invention can be applied to an air cleaning device used for deodorization, dioxin decomposition, pollen decomposition and the like, a plasma generator and a reaction device mounted on plasma etching, a thin film device and the like. In addition, the present invention can be applied to a plasma generator and its reaction apparatus for reacting or decomposing a fluid passing through a cavity by a plasma reaction.

FIG. 2 is a perspective view showing a configuration example of a plasma generator according to the first embodiment of the present invention. (A) is a top view of the plasma generator of FIG. 1, (b) is a side view of the plasma generator of FIG. 1 of (a). 2A is a cross-sectional view taken along line AA ′ of the plasma generator of FIG. 2A, FIG. 2B is a cross-sectional view taken along line BB ′ of FIG. 2B, and FIG. It is sectional drawing in CC 'line of 2 (b). It is sectional drawing which shows the other structural example of the plasma generator by the 1st Embodiment of this invention. It is a conceptual diagram which shows the structural structure of the reaction apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the electric system of the reaction apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 ... Plasma generator 2 ... Base | substrate 3 ... Dielectric 4 ... Supporting part 6 ... Cavity 5a, 5b ... Conductivity Body 7a, 7b ... external terminal

Claims (11)

A plurality of dielectrics arranged in one direction and a conductor disposed inside each of the dielectrics, and a voltage is applied between the conductors to form a discharge space between the dielectrics; A plasma generator capable of generating plasma,
4 or more of the dielectrics;
The facing area between the conductors facing each other across the discharge space at the center in the arrangement direction of the dielectric is larger than the facing area between the conductors facing across the discharge space at the end in the arrangement direction. Even a small plasma generator.   In the case where there are an even number of the dielectrics, the opposing area between the conductors facing each other across the discharge space at the center in the arrangement direction of the dielectrics is equal to the conductive surfaces facing each other across the discharge space at the end. The plasma generator according to claim 1, wherein the plasma generator is smaller than an opposing area between the bodies.   When there are an odd number of dielectrics, the opposing area between a pair of the conductors facing each other across one of the two discharge spaces adjacent in the center in the arrangement direction of the dielectrics, or each of the two 2. The plasma generator according to claim 1, wherein a facing area between the two sets of conductors facing each other across the discharge space is smaller than a facing area between the conductors facing each other across the discharge space at the end. .   The opposing area between the first conductor disposed in the dielectric between the two discharge spaces adjacent in the center and the second conductor adjacent to the first conductor is The plasma generator according to claim 3, wherein the plasma generator is smaller than a facing area between the second conductors facing each other across one conductor.   At least one of the two conductors facing each other across the discharge space at the center has a through hole inside the outer edge of the other conductor of the two conductors when viewed in plan. Item 3. The plasma generator according to Item 2.   At least one of the three conductors facing each other across the two discharge spaces adjacent to each other in the center of the arrangement direction of the dielectrics is the at least one of the three conductors. The plasma generator according to claim 3, wherein the plasma generator has a through hole inside an outer edge of the conductor adjacent to the body.   The plasma generator according to claim 2, wherein at least one of the two conductors facing each other across the central discharge space has a through hole at a position corresponding to a central portion of the central discharge space.   At least one of the three conductors facing each other across the two adjacent discharge spaces has a through hole at a position corresponding to a central portion of at least one of the two discharge spaces adjacent to each other. The plasma generator according to claim 3.   The plasma generator according to any one of claims 1 to 8, wherein an opposing area between the conductors gradually decreases from an end portion to a center portion in the arrangement direction of the dielectrics. A manufacturing method for manufacturing the plasma generator according to any one of claims 1 to 9,
Production of plasma generator, wherein said dielectric and said conductor disposed inside said dielectric are formed by simultaneously firing a plurality of ceramic green sheets and a conductive paste disposed between said ceramic green sheets Method. A plasma generator according to any one of claims 1 to 9,
A power source for applying an AC voltage or a pulse voltage between the conductors of the plasma generator;
A reaction apparatus comprising a supply unit capable of supplying a fluid between the dielectrics.

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