JP2016030231A - Gas treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably generate plasma discharge even in a case of treating flue gas.SOLUTION: Electrodes 2a, 2b are each formed by fixedly attaching a conductor 4 to an inner surface of a straight tube type dielectric 3. A plurality of electrodes 2a, 2b arranged in parallel are connected to terminals 13a, 13b in parallel to form a first electrode group 7 and a second electrode group 8. In a gas flow passage 11 within a square pillar frame 10, the electrodes 2a, 2b of the respective electrode groups 7, 8 are arranged to be stacked into a lattice state so as to contact one another. In this state, base end portions of the respective electrodes 2a, 2b are fixed to sidewalls 14a, 14b, 14c, 14d of the frame 10 and tip end portions thereof are held to be displaceable in a longitudinal direction. A power supply device 9 for applying an AC voltage is connected to the terminals 13a, 13b of the respective electrode groups 7, 8. Limiting deformations of the electrodes 2a, 2b by thermal expansion to extensional deformations in the longitudinal direction can prevent displacements of contact portions between the electrodes 2a, 2b and changes in relative positions of the electrodes 2a, 2b in a plasma generation area.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas processing apparatus that uses plasma to decompose or detoxify odorous substances and environmental pollutants in a gas to be processed.

  When gases containing environmental pollutants and odorous substances are discharged, gas treatment is required for decomposing or detoxifying these substances.

  As a method for performing gas treatment of a gas to be treated containing this type of environmental pollutant or odorous substance, a treatment method using plasma discharge generated under atmospheric pressure has been recently considered (for example, see Patent Document 1). .

  One method for generating plasma under atmospheric pressure is dielectric barrier discharge (DBD). This is because one or both of the paired conductors are covered with a dielectric (insulator), and an AC voltage is applied between the conductors, whereby the gap between the conductors and the dielectric, or the gap between the dielectrics. In addition, plasma discharge is generated.

  As plasma generating means by the dielectric barrier discharge method, for example, a conductor coated with a ceramic tube serving as a dielectric is used as a warp (warp), and an uncoated linear conductor is used as a weft (weft). Conventionally proposed is a fabric structure (fabric-like structure) in which warp yarns and weft yarns are alternately crossed up and down.

  Furthermore, plasma generating means having a fabric structure in which conductors coated on a ceramic tube are warps (warp) and wefts (wefts), and these warps and wefts are alternately crossed up and down to form a fabric structure. Proposed.

  Further, examples of the ceramic include quartz and borosilicate glass. Furthermore, it is said that the ceramic tube can be bent into a necessary shape due to thermal plasticity by using a glass tube (see, for example, Patent Document 2 (FIGS. 1 and 8)).

  Note that the plasma discharge by the dielectric barrier discharge is so-called low temperature plasma in which the gas temperature is low even if the electron temperature is high. For this reason, the temperature of the conductor and dielectric in the dielectric barrier discharge type plasma generating means generally rises only about 10 ° C. from room temperature.

  By the way, the dielectric barrier discharge type plasma generating means disclosed in Patent Document 2 is intended for surface modification of an object to be processed. For this purpose, the dielectric barrier discharge plasma generation means disclosed in Patent Document 2 is used for gas treatment of a gas to be treated, particularly combustion discharged from a combustion facility such as a fossil fuel combustion furnace or a waste incinerator. The following problems occur when applying to gas processing using exhaust gas as a processing target gas.

  That is, the combustion exhaust gas is at a high temperature of about 200 ° C. even when it is led to a gas processing apparatus using activated carbon, a catalyst, or the like that is usually provided in combustion equipment.

  Therefore, it is necessary for a gas processing apparatus for processing such flue gas to be free from trouble even if its constituent members undergo thermal expansion accompanying a temperature change from room temperature to a high temperature of about 200 ° C. Is done.

  In particular, when generating a plasma discharge of a dielectric barrier discharge between dielectrics, it is necessary to manage the spacing between the dielectrics in millimeters, and the spacing between the dielectrics becomes wide or uneven. If this happens, plasma discharge due to dielectric barrier discharge is generated in a place where electricity easily flows, and streamer discharge may occur.

  However, in the plasma generating means having the fabric structure shown in Patent Document 2, the ceramic tubes that cover the conductor to form the warp and the weft are both serpentine in the vertical direction, and are upwardly facing each other. The concave portions and the downward concave portions are sequentially combined. Therefore, when thermal expansion occurs in each ceramic tube forming the warp and weft, the position of the concave portion of each ceramic tube is displaced in the longitudinal direction of the ceramic tube. Since the contact point is displaced or moved away, it is difficult to manage the size of the gap desired for generating the plasma discharge.

  Further, when a temperature change from room temperature to about 200 ° C. occurs, a difference in deformation amount due to a difference in linear expansion coefficient occurs between the conductor and the ceramic tube covering the conductor, and the conductor and the ceramic tube. The relative position is also considered to change, but Patent Document 2 does not show any countermeasures.

  In addition, combustion exhaust gas may change the components in the gas in accordance with changes in properties of the combustion equipment. Further, the combustion exhaust gas may contain a corrosive gas such as hydrochloric acid gas or sulfuric acid gas.

  Patent Document 2 discloses the idea that both the warp and the weft in the plasma generating means having a fabric structure in which the warp and the weft are woven are covered with a ceramic tube. The idea of using a glass tube as the ceramic tube is also shown. Therefore, it can be considered that a countermeasure for avoiding corrosion by corrosive gas is possible.

  Next, when the scale of the combustion facility is large, the flow rate of the combustion exhaust gas increases. Therefore, in the exhaust gas duct through which the combustion exhaust gas circulates, the vertical and horizontal sizes of the channel cross section may be in the metric order. In this case, it is necessary that the gas treatment device is adapted to the cross-sectional shape of the exhaust gas duct.

  Therefore, in order to apply the plasma generating means shown in Patent Document 2 to such a large gas processing apparatus, it is necessary to set the longitudinal dimension of each conductor and ceramic tube as long as several meters. .

  However, when the longitudinal dimension of the conductor or the ceramic tube becomes long, the bending deformation due to its own weight cannot be ignored. When such bending deformation occurs, a change occurs in the relative positions of the ceramic tubes forming the warp and the weft.

  Furthermore, when the total length of the conductor and the ceramic tube is long, the change in the longitudinal dimension of the conductor and the ceramic tube due to the thermal expansion accompanying the above-described temperature change is enlarged. In addition, there is a possibility that damage such as cracking may occur in the ceramic tube as a dielectric due to thermal stress.

  Therefore, conventionally, even when a gas containing a corrosive gas such as combustion exhaust gas from a combustion facility or a high-temperature gas is used as a processing target gas, it is possible to stably generate a plasma discharge due to dielectric barrier discharge. The fact is that no gas treatment device has been proposed.

JP 2006-187766 A JP 2013-65430 A

  In view of this, the present invention can be processed by a plasma discharge of a dielectric barrier discharge that generates a gas to be processed between electrodes. Furthermore, even when the combustion exhaust gas from a combustion facility is used as a gas to be processed, the dielectric An object of the present invention is to provide a gas treatment apparatus capable of stably generating plasma discharge of body barrier discharge.

  In order to solve the above-mentioned problems, the present invention, corresponding to claim 1, forms an electrode formed by bringing a conductor into close contact with the inner surface of a straight tube-shaped dielectric, and includes a plurality of electrodes extending in one direction. A first electrode group that is arranged in parallel at a certain interval and has a conductor of each electrode connected in parallel to a terminal, and a plurality of other electrodes extending in a direction orthogonal to each electrode of the first electrode group To apply an alternating voltage to each terminal of each electrode group, and a second electrode group in which the electrodes of each electrode are arranged in parallel at a certain interval and the conductor of each electrode is connected in parallel to another terminal Each of the electrodes of the first electrode group and each of the second electrode group in the gas flow path inside the frame. The electrodes are stacked in a plurality of stages in contact with each other so as to form a grid, and each side wall of the frame Proximal end of each electrode of the pole group are fixed, and the tip portion of each electrode of each of the electrode groups is a gas treatment apparatus having a structure in which displaceably held in the longitudinal direction.

  Further, corresponding to claim 2, in the configuration corresponding to claim 1, each electrode of each electrode group stacked in the gas flow path inside the frame by a pair of electrode support members in the frame. Are arranged from both sides in the axial direction of the frame, and an electrode bending displacement preventing mechanism for preventing displacement due to bending deformation of each electrode is provided.

  Further, corresponding to claim 3, in the configuration corresponding to claim 1 or 2, a cleaning device is provided for performing blow cleaning on a portion of each electrode group arranged in the frame. The configuration is as described above.

  Furthermore, corresponding to claim 4, in the configuration corresponding to any one of claims 1 to 3, the power supply device compares a current current value with a preset current set value. If the current current value exceeds the preset allowable increase range on the current increase side with respect to the current setting value, the current current value is determined to be the current if the current voltage value is greater than the preset voltage lower limit value. Adjust the current voltage value when applying AC voltage to the first electrode group and the second electrode group by the feedback control method so that it matches the set value, and if the current voltage value is less than or equal to the lower voltage limit, The current value is set to have a constant current value control function for adjusting the pulse frequency by feedback control so that the current value matches the current set value.

  Similarly, corresponding to claim 5, in the configuration corresponding to any one of claims 1 to 3, the power supply device compares a current power value with a preset power setting value. If the current power value exceeds the preset allowable fluctuation range on the power increase side with respect to the power setting value, the current power value is the power if the current voltage value is greater than the preset voltage lower limit value. Perform processing to change the control waveform of the AC voltage applied to the first electrode group and the second electrode group by the feedback control method so that it matches the set value, and if the current voltage value is less than or equal to the voltage lower limit value, A constant power control function for adjusting the pulse frequency by feedback control is adopted so that the current value matches the power set value.

  Similarly, corresponding to claim 6, in the configuration corresponding to any one of claims 1 to 3, the power supply device compares the current current value with a preset current set value. When the condition that the current current value exceeds the preset allowable fluctuation range on the current increase side with respect to the current setting value is satisfied, the current voltage value is greater than the preset voltage lower limit value. The current voltage value when the AC voltage is applied to the first electrode group and the second electrode group is adjusted by the feedback control method so that the current current value matches the current setting value. If the current value is equal to the current set value, the current value constant control function that adjusts the pulse frequency by feedback control and the current current value is a preset current decrease with respect to the current set value. Side and current increase If the current power value is within the allowable power range on the side and the power setting value exceeds the preset allowable power range on the power increase side, the current voltage value is greater than the preset voltage lower limit value. In this case, the feedback voltage control method is used to change the control waveform of the AC voltage applied to the first electrode group and the second electrode group so that the current power value matches the power setting value. When the value is equal to or smaller than the value, the power is set to have a constant power control function for adjusting the pulse frequency by feedback control so that the current power value matches the power setting value.

According to the gas processing apparatus of the present invention, the following excellent effects are exhibited.
(1) The gas to be treated is a dielectric barrier discharge generated around the contact point between each electrode of the first electrode group and each electrode of the second electrode group by circulating the gas flow path inside the frame. It can be processed by plasma discharge.
(2) Even when the combustion exhaust gas from the combustion facility is used as the gas to be treated, plasma discharge of dielectric barrier discharge can be stably generated.

It is a general | schematic cutting side view which shows one Embodiment of the gas processing apparatus of this invention. It is an AA direction arrow line view of FIG. It is a BB direction arrow enlarged view of FIG. It is a perspective view which expands and shows the part by which the electrode of the 1st electrode group and the electrode of the 2nd electrode group in the apparatus of FIG. 1 were laminated | stacked. The electrode used with the apparatus of FIG. 1 is expanded and shown, (a) is a cut side view, (b) is a CC direction arrow directional view of (a). It is a general | schematic cutting side view which shows the other form of implementation of this invention. As still another embodiment of the present invention, another example of the cleaning device is shown, in which (a) is a schematic cut side view, and (b) is a view in the direction of arrows DD in (a). It is a flowchart which shows the electric current value fixed control performed with a power supply device as further another form of implementation of this invention. It is a flowchart which shows the electric power fixed control performed with a power supply device as further another form of implementation of this invention. It is a flowchart which shows the control procedure in the case of implementing combining current value constant control and electric power constant control in a power supply device as further another form of implementation of this invention. (A) and (b) are the schematic diagrams which show another example of arrangement | positioning of a 1st electrode group and a 2nd electrode group, respectively as another form of implementation of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 thru | or FIG. 5 (a) (b) shows one Embodiment of the gas processing apparatus of this invention.

  Here, first, the basic configuration of the electrodes 2a and 2b used in the gas processing apparatus 1 of the present invention will be described.

  As shown in FIGS. 5A and 5B, the electrodes 2 a and 2 b are composed of a straight tube-shaped dielectric 3 extending in one direction and a conductor 4 disposed in close contact with the inner surface of the dielectric 3. ing.

  The dielectric 3 is preferably made of a quartz tube in order to have heat resistance that can withstand the high temperatures of combustion exhaust gas and corrosion resistance that prevents corrosion by corrosive gas. The dielectric 3 may be a ceramic tube or a glass tube having no gas permeability on the tube wall.

  Further, the dielectric 3 has a configuration in which one end in the longitudinal direction serving as the tip is closed by the end wall material 3a, and prevents gas from entering the inside of the dielectric 3 from one end in the longitudinal direction.

  The conductor 4 has a configuration in which a slit 5 extending in the entire length in the longitudinal direction is provided at one place in the circumferential direction of the tube wall in a straight tube shape extending in one direction.

  The conductor 4 is preferably made of stainless steel in view of providing heat resistance similar to that of the dielectric 3 and enhancing corrosion resistance. As a method for producing the stainless steel conductor 4, a stainless steel pipe (SUS pipe) is used as a material, and a portion of the stainless steel pipe wall in the circumferential direction is cut out over the entire length in the longitudinal direction. The method of forming 5 is preferable.

  In the gas treatment apparatus 1 of the present invention, the material of the conductor 4 of the electrodes 2a and 2b is not limited to stainless steel, and has heat resistance and corrosion resistance, and between the electrodes 2a and 2b as will be described later. Of course, the conductor 4 made of a metal other than stainless steel or a non-metallic conductive material may be used as long as plasma discharge by dielectric barrier discharge can be generated. Of course, the manufacturing method of the conductor 4 is not limited to the manufacturing method from the pipe described above.

  The conductor 4 is urged so as to narrow the width of the slit 5 from the initial shape and elastically deformed so that the outer diameter becomes narrower, and the opening on the other end side in the longitudinal direction which becomes the base end of the dielectric 3 To the inside of the dielectric 3. As a result, the entire outer surface of the conductor 4 is brought into close contact with the inner surface of the dielectric 3 by a restoring force that expands from the elastically deformed state and returns to the initial shape inside the dielectric 3. Yes.

  In addition, about the dielectric material 3 and the conductor 4, the operating temperature range (henceforth only using temperature range) of the gas processing apparatus of this invention assumed beforehand as normal temperature to the highest temperature of the process target gas G is mentioned. The outer diameter in a state where the external force of the conductor 4 is not applied (initial shape) is set to be larger than the inner diameter of the dielectric 3 in the entire region.

  In addition, the internal dimension of the dielectric 3 in the longitudinal direction is set to be larger than the entire length of the conductor 4 in the entire operating temperature range. As a result, the dielectric 3 and the other end in the longitudinal direction of the conductor 4 inserted inside thereof are aligned with each other between the inner surface of the end wall member 3a of the dielectric 3 and the one end in the longitudinal direction of the conductor 4. A certain gap 6 is formed.

  In the electrodes 2a and 2b configured as described above, if there is a difference in deformation due to thermal expansion between the dielectric 3 and the conductor 4 due to the difference in linear expansion coefficient between the dielectric 3 and the conductor 4, the dielectric 3 The outer surface of the conductor 4 slides in close contact with the inner surface.

  Therefore, in the operating temperature range, the difference in the amount of thermal expansion deformation in the circumferential direction between the dielectric 3 and the conductor 4 caused by the difference in the coefficient of linear expansion causes the width of the slit 5 of the conductor 4 to expand and contract. Absorbed in. Further, the difference in thermal expansion deformation amount in the longitudinal direction between the dielectric 3 and the conductor 4 is that the gap 6 between the inner surface of the end wall member 3a of the dielectric 3 and one end in the longitudinal direction of the conductor 4 is expanded or contracted. Is absorbed.

  Next, the structure of the gas processing apparatus 1 of the present invention using the electrodes 2a and 2b will be described.

  As shown in FIGS. 1 to 4, the gas processing apparatus 1 of the present invention is connected to a first electrode group 7 and a second electrode group 8 each including a plurality of electrodes 2 a and 2 b, and to the electrode groups 7 and 8. The power supply device 9, the inside of the cylindrical frame 10 in which the gas flow path 11 of the gas G to be processed and the electrode groups 7 and 8 are installed, and the electrodes disposed in the gas flow path 11 of the frame 10. The electrodes 7a and 2b of the groups 7 and 8 are composed of an electrode bending displacement prevention mechanism 12 that prevents displacement due to bending.

  In the first electrode group 7, a plurality of electrodes 2a having one end and the other end aligned in the longitudinal direction are arranged in parallel at a certain interval in one plane, and at the other end in the longitudinal direction of each electrode 2a. The conductor 4 exposed through the opening of the dielectric 3 is connected in parallel to a terminal 13a extending along the arrangement direction of the electrodes 2a.

  The second electrode group 8 includes a plurality of separate electrodes 2b having one end side and the other end side aligned in the longitudinal direction arranged in parallel at a certain interval in one plane, and the other end in the longitudinal direction of each electrode 2b. In this configuration, the conductor 4 exposed through the opening of the dielectric 3 is connected in parallel to another terminal 13b extending along the arrangement direction of the electrodes 2b.

  The terminal 13a of the first electrode group 7 and the terminal 13b of the second electrode group 8 are connected to a power supply device 9 for applying an alternating voltage.

  Each electrode 2a of the first electrode group 7 and each electrode 2b of the second electrode group 8 are stacked in such a manner that the electrodes 2a and 2b are in contact with each other in a posture oriented in a direction orthogonal to each other. Arranged in the gas flow path 11.

  The frame 10 has a rectangular tube shape. Of the two sets of opposing side walls 14a and 14c and side walls 14b and 14d of the frame 10, one side wall 14a and 14c has a direction along the axis of the frame 10 (hereinafter simply referred to as a frame axis direction). ), A plurality of electrode mounting holes 15 are formed in an arrangement corresponding to the arrangement of each electrode 2a of the first electrode group 7 along a direction perpendicular to the axial direction of the frame.

  The other pair of side walls 14b and 14d of the frame 10 are arranged in a direction perpendicular to the frame axial direction at a position that is an intermediate position in the axial direction of the frame and that is shifted from each electrode mounting hole 15 by a certain dimension. Thus, a plurality of electrode mounting holes 16 are formed in an arrangement corresponding to the arrangement of the electrodes 2b of the second electrode group 8.

  The center position of each electrode mounting hole 15 in the side walls 14a and 14c and the center position of each electrode mounting hole 16 in the side walls 14b and 14d are in the dielectric 3 (which constitutes each electrode 2a, 2b in the frame axis direction). The diameters are shifted by the amounts shown in FIGS. 5 (a) and 5 (b).

  Each electrode 2a of the corresponding arrangement of the first electrode group 7 is inserted and arranged in each electrode mounting hole 15 provided in the side walls 14a and 14c from the outside of the side wall 14a. At this time, each electrode 2a has a location near the base end (location near the other end in the longitudinal direction) in the corresponding electrode mounting hole 15 (inside the hole) of the side wall 14a, and a location near the tip of each electrode 2a ( The portion near one end in the longitudinal direction) is located in the corresponding electrode mounting hole 15 (in the hole) of the side wall 14c.

  Further, in each electrode mounting hole 15 of the side wall 14a, a portion near the base end of each corresponding electrode 2a is fixed via an insulating sleeve 17 attached to the outer periphery thereof.

  Further, the tip end side of each corresponding electrode 2a is attached to each electrode attachment hole 15 of the side wall 14c via a bottomed cylindrical insulator 18 loosely fitted to the tip end side of each electrode 2a. At this time, between the inner bottom surface of the bottomed cylindrical insulator 18 and the tip of the corresponding electrode 2a, the amount of deformation of thermal expansion that occurs in the operating temperature range of the dielectric 3 of the electrode 2a at room temperature. A gap corresponding to is provided.

  On the other hand, each electrode 2b of the corresponding arrangement of the second electrode group 8 is inserted and arranged in each electrode mounting hole 16 provided in the side walls 14b and 14d from the outside of the side wall 14b. At this time, each electrode 2b has a location near the base end (location near the other end in the longitudinal direction) located in the corresponding electrode mounting hole 16 (inside the hole) of the side wall 14b, and a location near the tip (close to one end in the longitudinal direction). Is located in the corresponding electrode mounting hole 16 (inside the hole) of the side wall 14d.

  Further, in the electrode mounting holes 16 of the side walls 14b, the portions near the base ends of the corresponding electrodes 2b are fixed via insulating sleeves 17 attached to the outer periphery thereof.

  Further, the tip end side of each corresponding electrode 2b is attached to each electrode mounting hole 16 of the side wall 14d via a bottomed cylindrical insulator 18 loosely fitted to the tip end side of each electrode 2b. At this time, between the inner bottom surface of the bottomed cylindrical insulator 18 and the tip of the corresponding electrode 2b, the amount of deformation of thermal expansion that occurs in the operating temperature range of the dielectric 3 of the electrode 2b at normal temperature. A gap corresponding to is provided.

  The insulating sleeve 17 and the bottomed cylindrical insulator 18 are made of a material having a desired corrosion resistance depending on the properties, gas components, and temperature of the processing target gas G flowing through the gas flow path 11 inside the frame 10. Any insulating material having heat resistance may be used, and preferably quartz, mica, or fluororesin (polytetrafluoroethylene) may be used.

  Further, between each electrode mounting hole 15 and 16 and each corresponding insulating material sleeve 17, between each insulating material sleeve 17 and the dielectric 3 of the electrodes 2 a and 2 b inside thereof, and each electrode Sealing between the mounting holes 15 and 16 and the corresponding bottomed cylindrical insulator 18 with a sealing material (not shown) prevents leakage of the processing target gas G flowing through the gas flow path 11 inside the frame 10. It is like that.

  Thereby, in the gas flow path 11 inside the flame | frame 10, each electrode 2a of the 1st electrode group 7 and each electrode 2b of the 2nd electrode group 8 are laminated | stacked along the surface perpendicular | vertical to a frame axial direction. And arranged in a grid pattern.

  Further, as described above, the center position of each electrode mounting hole 15 on the side walls 14a and 14c and the center position of each electrode mounting hole 16 on the side walls 14b and 14d are the dielectric 3 of the electrodes 2a and 2b in the frame axial direction. Since each of the electrodes 2a of the first electrode group 7 and each electrode 2b of the second electrode group 8 is at an intersecting portion, the dielectric 3 The outer surfaces of each other are in contact with each other.

  Therefore, as schematically shown in FIG. 4, there is a dielectric 3 of each electrode 2a (see FIGS. 5A and 5B) and each electrode around the contact point 19 at the intersection of each electrode 2a and 2b. As shown in FIG. 4, hatched areas are shown in FIG. 4 where the space between the dielectrics 3 of 2b (see FIGS. 5A and 5B) is a gap of several millimeters suitable for plasma discharge by dielectric barrier discharge. This region is the plasma generation region 20. Further, each lattice portion formed by each electrode 2a and 2b serves as a gas passage 21 for the processing target gas G. Therefore, the processing target gas G guided to the gas flow path 11 inside the frame 10 is subjected to processing by plasma discharge by dielectric barrier discharge generated in the plasma generation region 20 in the vicinity thereof when passing through the gas passage 21. It is like that.

  When the processing target gas G is combustion exhaust gas from the combustion facility, the electrodes 2a and 2b arranged in the gas flow path 11 inside the frame 10 are affected by the temperature of the processing target gas G. Thereby, thermal expansion arises in each electrode 2a, 2b with the temperature change in a use temperature range. At this time, since the outer shape of each electrode 2a, 2b is a straight tube shape by the dielectric 3 (FIGS. 5A and 5B), deformation due to thermal expansion of each electrode 2a, 2b is mainly dielectric. 3 in the longitudinal direction.

  In the thermal expansion of each of the electrodes 2a and 2b, the diameter of the dielectric 3 is also increased, but the amount of deformation is slight compared to the elongation deformation.

  As described above, the expansion deformation due to the thermal expansion of the dielectric 3 generated in each of the electrodes 2a and 2b is attached to the side walls 14c and 14d of the frame 10 to hold the tip side of each of the electrodes 2a and 2b. Inside the cylindrical insulator 18, the tip of the dielectric 3 of each electrode 2a, 2b is absorbed by sliding.

  Therefore, when the combustion exhaust gas as described above is processed as the processing target gas G, even if thermal expansion occurs in the electrodes 2a and 2b, the positions of the electrodes 2a and 2b do not change, and the respective dielectrics 3 Only the outer surfaces slide. For this reason, since the contact state between each electrode 2a and 2b does not change, the position of the contact point 19 between each electrode 2a and 2b does not change, and in the plasma generation region 20 formed around the contact point 19, A change in the relative position between the electrodes 2a and 2b is prevented.

  The electrode deflection displacement prevention mechanism 12 detects that each electrode 2a of the first electrode group 7 and each electrode 2b of the second electrode group 8 arranged in the frame 10 are deflected and displaced in the frame axial direction. It is for preventing.

  For this reason, the electrode deflection displacement prevention mechanism 12 sandwiches each electrode 2a of the first electrode group 7 and each electrode 2b of the second electrode group 8 stacked in the frame 10 from both sides in the frame axial direction. The electrode support members 22a and 22b arranged in the above are provided.

  The first electrode support member 22a is a member extending in a direction orthogonal to the longitudinal direction of each electrode 2a of the first electrode group 7, and the longitudinal direction of each electrode 2a with respect to all the electrodes 2a of the first electrode group 7 It arrange | positions so that the contact location 19 in an intermediate part may contact | connect the outer surface of the position which opposes 180 degree | times. In this state, both ends of the first electrode support member 22a are fixed to the side walls 14b and 14d of the frame 10.

  The second electrode support member 22b is a member extending in a direction perpendicular to the longitudinal direction of each electrode 2b of the second electrode group 8, and the second electrode support member 22b It arrange | positions so that the contact location 19 in a longitudinal direction intermediate part may contact | connect the outer surface of a position which opposes 180 degree | times. In this state, both ends of the second electrode support member 22b are fixed to the side walls 14a and 14c of the frame 10.

  Each electrode support member 22a does not impede the flow of the processing target gas G in the gas flow path inside the frame 10 and has a frame axis center in order to increase the rigidity in the direction along the frame axis direction. It has a certain width dimension for obtaining a desired rigidity along the direction, and has a thin flat plate shape in a direction orthogonal to the frame axial direction.

  Although not shown in the drawings, the first electrode support member 22a and the second electrode support member 22b are provided at a plurality of positions in the longitudinal direction of each electrode 2a according to the longitudinal dimension and ease of bending of each electrode 2a, 2b. Of course, the electrodes 2b may be provided at a plurality of locations in the longitudinal direction.

  According to the electrode deflection displacement prevention mechanism 12 having the above configuration, as shown in FIGS. 1 and 2, when the frame axial direction is the vertical direction, it is provided below the electrodes 2a and 2b. By receiving the electrodes 2a and 2b on the electrode support member 22b, the electrodes 2a and 2b can be prevented from being displaced downward due to bending deformation due to their own weight.

  Further, as will be described later, when the gas G to be processed flows through the gas flow path 11 inside the frame 10 upward from below, the cleaning device 23 described later further blow-cleans the electrodes 2a and 2b from below. When performing, an upward force may act on each electrode 2a and 2b by an airflow. In this case, the electrodes 2a and 2b are directed upward by receiving an upward force acting on the electrodes 2a and 2b as described above by the electrode support member 22a provided above the electrodes 2a and 2b. Therefore, it is possible to prevent deformation and displacement.

  Therefore, the electrodes 2a and 2b, which are prevented from being displaced by the electrode deflection displacement prevention mechanism 12, retain the straight tube shape of the dielectric 3 (see FIGS. 5A and 5B).

  Furthermore, since each electrode supporting member 22a, 22b is only in contact with the outer surface of each electrode 2a, 2b, the thermal expansion accompanying the temperature change in the above-mentioned temperature range of use of each electrode 2a, 2b is nothing. There is no impact.

  Thereby, according to the structure provided with the electrode deflection displacement prevention mechanism 12, the size of the cross section of the gas flow path 11 inside the frame 10 is large, and the electrodes 2a and 2b arranged in the gas flow path 11 are long. Even if it is a scale, since the change in the position of the contact point 19 between the electrodes 2a and 2b can be prevented, in the plasma generation region 20 formed around the contact point 19, the relative position between the electrodes 2a and 2b can be reduced. Changes can be prevented.

  By the way, when processing the combustion exhaust gas of the combustion facility as the processing target gas G, the gas component contained in the processing target gas G changes variously according to the components and the combustion state of the combustion in the combustion facility. Therefore, depending on the gas component contained in the processing target gas G, the processing target gas G is generated in the plasma generation region 20 through the gas passage 21 formed by the electrodes 2 a and 2 b in the gas flow path 11. When processing by plasma discharge of dielectric barrier discharge is performed, deposits may be generated on the electrodes 2a and 2b.

  When the deposits attached to the electrodes 2a and 2b cause the same dielectric action as the dielectric 3 (see FIGS. 5A and 5B) of the electrodes 2a and 2b, As if the change of the position of the contact point 19 between the electrodes 2a and 2b and the change of the relative position of the electrodes 2a and 2b in the plasma generation region 20 occur, the generation of the plasma discharge is biased or the plasma discharge There is a risk that the occurrence of the phenomenon itself becomes unstable.

  Therefore, it is desirable that the gas treatment device 1 of the present invention further includes a cleaning device 23 for the electrodes 2a and 2b.

  The cleaning device 23 is disposed on one side in the axial direction of the frame 10, for example, a cleaning device frame 24 for connection to the lower side of the frame 10 and an inner side of the cleaning device frame 24 as shown in FIGS. 1 and 2. And it is set as the structure provided with the injection nozzle 25 for injecting the cleaning gas 26 toward each electrode 2a, 2b.

  The cleaning device frame 24 has a rectangular tube shape having the same cross-sectional shape as the frame 10. A pair of guide rails 27 arranged so as to extend along a plane perpendicular to the axial direction of the frame are provided opposite to each other on the inner wall surfaces of a pair of opposing side walls 24 a and 24 b of the cleaning device frame 24.

  On the upper surface of each guide rail 27, both longitudinal ends of a header pipe 28 extending in a direction perpendicular to each guide rail 27 are supported so as to be slidable in the longitudinal direction of each guide rail 27.

  The spray nozzles 25 are attached to the header pipe 28 at a plurality of positions in the longitudinal direction so as to face the direction (upward) of the positions where the electrodes 2a and 2b are installed.

  One end of a cleaning gas supply pipe 29 inserted in the cleaning apparatus frame 24 from the outside in a horizontal direction through another side wall 24c of the cleaning apparatus frame 24 is provided on one side surface of the intermediate portion in the longitudinal direction of the header pipe 28. (Tip) is connected. It is assumed that a cleaning gas supply device (not shown) is connected to the other end portion of the cleaning gas supply pipe 29 located outside the cleaning device frame 24. As the cleaning gas 26, air, nitrogen gas, other inert gas, steam, and other gases generally used for blow cleaning may be appropriately selected and used according to the use situation.

  Furthermore, a drive device 30 such as an actuator for reciprocating the header pipe 28 and each injection nozzle 25 along the guide rail 27 integrally with the cleaning gas supply pipe 29 is provided outside the cleaning apparatus frame 24. As a configuration.

  The cleaning device 23 configured as described above passes through a cleaning gas supply pipe 29 from a cleaning gas supply device (not shown) every predetermined period or every certain operation time of the gas processing apparatus 1 of the present invention. The guided high-pressure cleaning gas 26 is supplied to the header pipe 28 and is injected from the injection nozzles 25 toward the electrodes 2a and 2b. Further, while jetting the cleaning gas 26 from each jet nozzle 25, the driving device 30 causes the header pipe 28 and each jet nozzle 25 to be along the guide rail 27 via the cleaning gas supply pipe 29. Move back and forth. Thereby, the part arrange | positioned in the gas flow path 11 inside the flame | frame 10 in each electrode 2a, 2b is blow-cleaned by the high-pressure cleaning gas 26 injected from each injection nozzle 25.

  Therefore, in each electrode 2a, 2b, the deposit | attachment adhering to the surface can be blown away by the high pressure cleaning gas 26, and can be removed. For this reason, even if a deposit adheres to each of the electrodes 2a and 2b when performing the processing by the plasma discharge of the dielectric barrier discharge of the processing target gas G, the deposit is prevented from growing. Therefore, problems such as the occurrence of bias in plasma discharge generation or instability of plasma discharge generation due to the growth of deposits that cause dielectric action as described above can be prevented.

  The frame 10 is provided with a cover 31 that covers the terminals 13a of the first electrode group 7 and the terminals 13b of the second electrode group 8 outside the attachment positions of the electrodes 2a and 2b.

  When the combustion exhaust gas of the combustion facility is processed as the processing target gas G using the gas processing apparatus 1 of the present invention having the above configuration, the cleaning device frame 24 of the cleaning device 23 provided in advance on the lower side of the frame 10. Is connected to the downstream side of the exhaust gas duct X that guides the combustion exhaust gas of the combustion facility. Further, the upper end side of the frame 10 is connected to another exhaust gas duct X1 for sending the treated gas to a discharge facility (not shown) on the downstream side.

  Thus, when connecting the gas treatment device 1 of the present invention to the exhaust gas ducts X and X1, as shown in FIGS. 1 and 2, the upper end of the cleaning device frame 24 of the cleaning device 23 and the exhaust gas duct X1 are connected. A chamber 32 that can accommodate the gas processing apparatus 1 of the present invention is provided between the upstream end and the gas processing apparatus 1 of the present invention may be disposed on the inner bottom surface of the chamber 32. In this case, the gas processing apparatus 1 of the present invention uses a fixing means (not shown) in the chamber 32 to constrain the flow direction of the processing target gas G so as not to be displaced, and a direction orthogonal to the direction (see FIG. In the horizontal direction, the frame 10 and the cover 31 are held in a state where deformation due to thermal expansion is allowed. According to this configuration, the thermal stress acting on the frame 10 and the cover 31 can be reduced in the gas processing apparatus 1 of the present invention. For this reason, it becomes possible to relieve | moderate the thermal stress which acts on each electrode 2a, 2b supported by the flame | frame 10 more reliably.

  In this state, in the gas treatment device 1 of the present invention, an AC voltage is applied from the power supply device 9 to the terminal 13a of the first electrode group 7 and the terminal 13b of the second electrode group. As a result, in the gas flow path 11 inside the frame 10, the generation of plasma around the contact points 19 between the electrodes 2 a of the first electrode group 7 and the electrodes 2 b of the second electrode group 8 arranged in a grid pattern. In region 20, a plasma discharge is generated by a dielectric barrier discharge.

  Thereafter, the combustion exhaust gas guided through the exhaust gas duct X is circulated through the gas passage 11 as the processing target gas G.

  Thereby, when the processing target gas G supplied to the gas flow path 11 passes through the gas passages 21 formed by the electrodes 2a and 2b arranged in a lattice shape in the gas flow path 11, the vicinity of the gas G Processing is performed by the plasma discharge generated in the plasma generation region 20, and the odorous substances and environmental pollutants in the processing target gas G are decomposed and detoxified.

  Under the present circumstances, even if the temperature of each electrode 2a, 2b rises under the influence of the temperature of process target gas G, the deformation | transformation which arises in each electrode 2a, 2b by thermal expansion is restricted to the expansion deformation of a substantially longitudinal direction. For this reason, in the electrodes 2a and 2b in which the outer surfaces of the straight tube-shaped dielectric 3 are in contact with each other, a change in the position of the contact point 19 is prevented, and a plasma generation region formed around the contact point 19 In 20, the relative position change between the electrodes 2a and 2b is prevented.

  As described above, according to the gas treatment apparatus 1 of the present invention, the relative positions of the electrodes 2a and 2b that generate the plasma discharge of the dielectric barrier discharge can be managed, and the plasma discharge of the dielectric barrier discharge can be made uniform. And can be generated stably.

  Furthermore, in the configuration in which the electrode deflection displacement prevention mechanism 12 is provided in the gas flow path 11 inside the frame 10, the weight of each electrode 2 a, 2 b arranged in the gas flow path 11 is self-weighted or the gas flow of the processing target gas G Moreover, it can prevent that the deformation | transformation which bends with external force like the airflow at the time of blow cleaning arises. For this reason, in the gas treatment device 1 of the present invention having the configuration including the electrode deflection displacement prevention mechanism 12, the cross-sectional shape of the gas flow path 11 of the frame 10 is increased, and each electrode 2 a disposed in the gas flow path 11. Even when 2b is long, the possibility that the electrodes 2a and 2b are displaced due to the bending deformation as described above can be eliminated. Therefore, in this case, even if the cross-sectional shape of the gas flow path 11 of the frame 10 is enlarged when a large amount of the processing target gas G such as the combustion exhaust gas of the combustion facility is required, the plasma generation region 20 The relative positions of the electrodes 2a and 2b can be easily managed, and the plasma discharge of the dielectric barrier discharge can be made uniform and stabilized.

  In addition, the gas processing apparatus 1 according to the present invention is configured to include the cleaning device 23, so that even if deposits are generated on the electrodes 2 a and 2 b during the processing by plasma discharge of the gas G to be processed, the deposits Can be removed by blow cleaning. For this reason, the gas processing apparatus 1 of the present invention provided with the cleaning device 23 is a combustion facility that is assumed to contain a gas component that generates deposits on the electrodes 2a and 2b as described above during processing by plasma discharge. Even when the combustion exhaust gas is used as the processing target gas G, by preventing the growth of deposits attached to the electrodes 2a and 2b, it is possible to change the position of the contact point 19 between the electrodes 2a and 2b as well as plasma. As if the relative position between the electrodes 2a and 2b in the generation region 20 is changed, it is possible to prevent the generation of the plasma discharge from being biased or the generation of the plasma discharge itself from becoming unstable. Therefore, also in this case, the plasma discharge of the dielectric barrier discharge can be made uniform and stabilized.

  Next, FIG. 6 shows a modification of the embodiment shown in FIGS. 1 to 5A and 5B as another embodiment of the present invention.

  In the gas processing apparatus 1 of the present embodiment, each electrode support member 22a, 22b in the electrode deflection displacement prevention mechanism 12 has a rectangular flat plate shape in the same configuration as shown in FIGS. 1 to 5A and 5B. In place of the configuration described above, the electrode support members 22a and 22b are arranged along the outer surfaces of the electrodes 2a and 2b at a plurality of locations corresponding to the arrangement of the electrodes 2a and 2b at the edge contacting the electrodes 2a and 2b. A semicircular electrode fitting notch 33 is provided.

  Thereby, each electrode supporting member 22a, 22b can receive each corresponding electrode 2a, 2b inside each notch 33 for electrode fitting. For this reason, the electrodes 2a and 2b are displaced by bending deformation in the direction in which the electrodes 2a and 2b are arranged in addition to displacement due to bending deformation in the frame axial direction by the electrode support members 22a and 22b. Will also be restrained.

  Therefore, the gas processing apparatus 1 according to the present embodiment can be used by arranging the frame axial direction in a horizontal orientation or any other angle orientation as shown in FIG.

  Further, as shown in FIG. 6, the electrode deflection displacement prevention mechanism 12 includes a biasing means 34 for biasing the electrode support members 22 a and 22 b in a direction in which the electrode support members 22 a and 22 b are pressed against the corresponding electrodes 2 a and 2 b. Also good.

  For example, the urging means 34 may be a spring that exerts an elastic force in the contraction direction as shown in FIG.

  Although not shown, the urging means 34 is a spring that exerts an elastic force in the extending direction as long as the electrode supporting members 22a and 22b can be urged in the direction of pressing against the corresponding electrodes 2a and 2b. May be used. The spring type may be a spring using gas pressure, such as a plate spring, a disc spring, or an air spring, or any other spring other than a coil spring. Furthermore, the biasing means may use the restoring force of the elastically deformed member or may use an actuator.

  Other configurations are the same as those shown in FIGS. 1 to 5A and 5B, and the same components are denoted by the same reference numerals.

  The gas processing apparatus 1 according to the present embodiment can be used in the same manner as the gas processing apparatus 1 shown in FIGS. 1 to 5A and 5B, and the same effect can be obtained.

  Next, FIGS. 7A and 7B show another example of the cleaning device as still another embodiment of the present invention.

  The cleaning device 23a in the gas processing device 1 of the present embodiment includes a cleaning device frame 24 similar to the cleaning device 23 in the embodiment of FIGS. 1 to 5A and 5B, and is provided in the cleaning device frame 24. Instead of the form of moving along the guide rail 27 together with the header pipe 28, the injection nozzle 25 is provided as a stationary swivel type.

  The stationary swivel type cleaning device 23 a includes a header pipe 28 disposed inside the cleaning device frame 24 so as to extend along a plane perpendicular to the frame axial direction at a position passing through the center of the cross section of the cleaning device frame 24. .

  The spray nozzles 25 are attached to the header pipe 28 at a plurality of positions in the longitudinal direction in the cleaning device frame 24 in a posture directed toward the direction (upward) of the positions where the electrodes 2a and 2b are installed.

  The header pipe 28 is connected to a distal end portion of a cleaning gas supply pipe 29 that is disposed outside through the corresponding side wall 24 c of the cleaning device frame 24.

  Further, outside the cleaning device frame 24, the header pipe 28 and the respective injection nozzles 25, which are integrated with the cleaning gas supply pipe 29, are not shown for reciprocating rotation within an angular range as shown in FIG. 7B. The driving device is provided.

  Other configurations are the same as those shown in FIGS. 1 to 5A and 5B, and the same components are denoted by the same reference numerals.

  The cleaning device 23a of the gas processing apparatus 1 of the present embodiment having the above-described configuration is a cleaning gas (not shown) every predetermined period or every certain operation time of the gas processing apparatus 1 of the present invention. A high-pressure cleaning gas 26 guided from the supply device through the cleaning gas supply pipe 29 is supplied to the header pipe 28 and is injected from each injection nozzle 25. Furthermore, while injecting the cleaning gas 26 from each of the injection nozzles 25, the header pipe 28 and each of the injection nozzles 25 are connected to each other via the cleaning gas supply pipe 29 by a driving device (not shown) in FIG. Reciprocate as shown. Thereby, the part arrange | positioned in the gas flow path 11 inside the flame | frame 10 in each electrode 2a, 2b is blow-cleaned by the high-pressure cleaning gas 26 injected from each injection nozzle 25.

  Therefore, the cleaning device 23a can achieve the same effects as the cleaning device 23 in the embodiment shown in FIGS. 1 to 5A and 5B.

  Incidentally, as described above, when the combustion exhaust gas from the combustion facility is processed as the processing target gas G, the properties of the processing target gas G supplied to the plasma generation region 20 may change.

  One of the changes in the properties of the processing target gas G is a change in temperature. As a result of the experiment, the inventors have found that when the temperature of the processing target gas G existing in the plasma generation region 20 increases, the power supply device 9 and the first electrode group 7 are connected to the first electrode group 7 during the operation of the gas processing apparatus 1 of the present invention. It has been found that even when a constant voltage (alternating voltage) is applied to the two-electrode group 8, a phenomenon that the current value rises occurs.

  Further, another property change of the processing target gas G is a change in the gas component contained in the processing target gas G. This is due to the fact that the gas components generated during combustion change according to the components and the combustion conditions of the combustion equipment. As a result of the experiment, the present inventors have found that when a processing target gas G containing a specific gas component is present in the plasma generation region 20, a constant voltage (alternating current voltage) generated by the power supply device 9 is used as described above. ) Has been found to cause an increase in current value.

  Therefore, in order to stably generate the plasma discharge due to the dielectric barrier discharge in the gas treatment apparatus 1 of the present invention, even if the current value rise phenomenon occurs in the power supply apparatus 9 as described above, It is necessary that the power consumption does not exceed the power supply capacity of the facility to which the gas processing apparatus 1 of the present invention is applied. In view of this point, the power supply device 9 has a constant current value control as shown in FIG. 8, a constant power control as shown in FIG. 9, or a combination of constant current value control and constant power control as shown in FIG. It is desirable to have a function to perform control.

  FIG. 8 shows, as still another embodiment of the present invention, constant current value control performed by the power supply device 9 having the same configuration as that of the embodiment of FIGS. 1 to 5A and 5B.

  When performing constant current value control, the power supply device 9 is previously set with a current set value As desired as an upper limit value of the current value, and an allowable fluctuation range a on the current decrease side based on the current set value As, And the allowable fluctuation range b on the current increasing side is set. Further, the power supply device 9 includes a voltage upper limit value Vh and a voltage lower limit value Vl, and a pulse frequency upper limit value Hh and a pulse frequency lower limit value Hl for the AC voltage applied to the first electrode group 7 and the second electrode group 8. Try to set it.

  In this state, the power supply device 9 firstly determines that the current current value Ap is within the allowable fluctuation range a on the current decrease side or within the allowable fluctuation range b on the current increase side with respect to the current setting value As (As It is determined whether or not −a ≦ Ap ≦ As + b) is satisfied (step Sa1).

  If it is determined in step Sa1 that the current current value Ap satisfies the condition (As−a ≦ Ap ≦ As + b), the power supply device 9 is set in advance while maintaining the operation state at that time. The determination process in step Sa1 is repeated at a certain sampling period.

  On the other hand, when it is determined in step Sa1 that the current current value Ap does not satisfy the condition (As−a ≦ Ap ≦ As + b), the power supply device 9 proceeds to step Sa2, and the current current value Ap is Then, it is determined whether or not a condition (Ap> As + b) that exceeds the allowable fluctuation range b on the current increase side with respect to the current set value As is satisfied.

  If it is determined in step Sa2 that the current current value Ap satisfies the condition (Ap> As + b), it is necessary to reduce the current current value Ap.

  Therefore, the power supply device 9 proceeds to step Sa3 and determines whether or not a condition that the current voltage value Vp is larger than the voltage lower limit value Vl (Vp> Vl) is satisfied. If it is determined in step Sa3 that the current voltage value Vp satisfies the condition (Vp> Vl), the voltage can be lowered within the range from the current voltage value Vp to the voltage lower limit value Vl. .

  Therefore, when it is determined in step Sa3 that the condition (Vp> Vl) is satisfied, the power supply device 9 proceeds to step Sa4 so that the current current value Ap matches the current setting value As that is the target value. A voltage PID adjustment process for reducing the current voltage value Vp is performed using a PID control technique as a feedback control technique. After the voltage is reduced by the voltage PID adjustment process, the power supply device 9 returns to step Sa1 and continues operation. Thereby, in the power supply device 9, since the voltage present value Vp when applying an alternating voltage to the first electrode group 7 and the second electrode group 8 is lowered, the current value of the power supply device 9 is increased by the current set value As. As a result, it is possible to prevent an increase beyond the allowable swing range b on the side.

  On the other hand, if it is determined in step Sa3 that the current voltage value Vp does not satisfy the condition (Vp> Vl), the voltage cannot be lowered from the current voltage value Vp. In this case, the power supply device 9 proceeds to step Sa5 to start adjusting the pulse frequency of the AC voltage applied to the first electrode group 7 and the second electrode group 8.

  In step Sa5, it is determined whether or not the condition (Hm> Hl) that the pulse frequency control value Hm of the AC voltage at that time is larger than the pulse frequency lower limit value Hl is satisfied. If it is determined in step Sa5 that the pulse frequency control value Hm satisfies the condition (Hm> Hl), the pulse frequency control value Hm can be lowered within the range up to the pulse frequency lower limit value Hl. is there.

  Therefore, when it is determined in step Sa5 that the condition (Hm> Hl) is satisfied, the power supply device 9 proceeds to step Sa6, and makes the current current value Ap coincide with the current set value As that is the target value. A frequency PID adjustment process for reducing the pulse frequency control value Hm is performed using the PID control method. After the pulse frequency control value Hm is lowered by the frequency PID adjustment process, the power supply device 9 returns to step Sa1 and continues operation. Thereby, in the power supply device 9, since the pulse frequency when applying an alternating voltage to the first electrode group 7 and the second electrode group 8 is lowered, and the average value of the current values necessary for plasma discharge is lowered, the power supply device The current value of 9 is prevented from rising beyond the allowable fluctuation range b on the current increase side of the current set value As.

  If it is determined in step Sa5 that the pulse frequency control value Hm does not satisfy the condition (Hm> Hl), if the pulse frequency control value Hm is further reduced, plasma due to dielectric barrier discharge is generated. It becomes difficult to generate a stable discharge. Therefore, the power supply device 9 proceeds to step Sa7, stops the control, and issues an alarm.

  As a result of the above processing, as described above, the temperature of the processing target gas G existing in the plasma generation region 20 increases, and the processing target gas G containing a specific gas component exists in the plasma generation region 20. Thus, the phenomenon that the current value rises can be dealt with by lowering the current voltage value Vp or lowering the pulse frequency control value Hm.

  In this state, when the phenomenon that caused the increase in the current value such as the temperature increase of the processing target gas G in the plasma generation region 20 or the presence of a specific gas component is improved or eliminated, In the current voltage value Vp and the pulse frequency control value Hm after adjustment to suppress the increase in the current value, the current value may be significantly lower than the current set value As. Therefore, in the current value constant control performed by the power supply device 9, when an AC voltage is applied from the power supply device 9 to the first electrode group 7 and the second electrode group 8, the current current value Ap is changed from the current set value As as described above. If the drop occurs, the drop is recovered.

  In view of this point, when it is determined by the determination in step Sa2 that the current current value Ap does not satisfy the condition (Ap> As + b), the current current value Ap is equal to the current set value As. Since the condition is lower than the reference allowable current fluctuation range a on the current decrease side (As-a> Ap), the process proceeds to step Sa8, and the process of raising the current current value Ap is started.

  In step Sa8, it is determined whether or not the pulse frequency control value Hm of the AC voltage at that time satisfies the condition (Hm ≦ Hh) that is equal to or lower than the pulse frequency upper limit value Hh. If it is determined in step Sa8 that the pulse frequency control value Hm satisfies the condition (Hm ≦ Hh), the pulse frequency control value Hm can be raised within the range up to the pulse frequency upper limit value Hh. is there.

  For this reason, when it is determined in step Sa8 that the condition (Hm ≦ Hh) is satisfied, the power supply device 9 proceeds to step Sa6, and the PID is set so that the current current value Ap matches the current set value As that is the target value. A frequency PID adjustment process for raising the pulse frequency control value Hm is performed using a control method.

  It should be noted that the frequency PID adjustment processing performed in step Sa6 increases the pulse frequency control value Hm when performed based on the determination processing of step Sa8, while the pulse frequency adjustment when performed based on the determination processing of step Sa5 described above. Although described as a process of lowering the control value Hm, the PID control method is used so that the current current value Ap coincides with the current set value As that is the target value, only the conditions at the start of the process are different. The process of adjusting the pulse frequency control value Hm based on this is the same.

  After the pulse frequency control value Hm is raised by the frequency PID adjustment process in step Sa6, the power supply device 9 returns to step Sa1 and continues operation. Thereby, in the power supply device 9, since the pulse frequency at the time of applying an alternating voltage to the 1st electrode group 7 and the 2nd electrode group 8 is pulled up and the average value of the current value required for plasma discharge is pulled up, the current value Excessive decline of is eliminated.

  On the other hand, if it is determined in step Sa8 that the pulse frequency control value Hm does not satisfy the condition (Hm ≦ Hh), the pulse frequency control value Hm cannot be further increased. Therefore, the power supply device 9 proceeds to step Sa9.

  In step Sa9, the power supply device 9 determines whether or not the current voltage value Vp satisfies the condition that the voltage upper value Vh is smaller than the voltage upper limit value Vh (Vp <Vh). If it is determined in step Sa9 that the current voltage value Vp satisfies the condition (Vp <Vh), it is possible to raise the voltage within the range from the current voltage value Vp to the voltage upper limit value Vh. .

  Therefore, when it is determined in step Sa9 that the condition (Vp <Vh) is satisfied, the power supply device 9 proceeds to step Sa4 so that the current current value Ap matches the current set value As that is the target value. A voltage PID adjustment process for raising the current voltage value Vp is performed using the PID control method.

  Note that the voltage PID adjustment process performed in step Sa4 increases the current voltage value Vp when performed based on the determination process of step Sa9, while the current voltage value when performed based on the determination process of step Sa3. Although described as a process of lowering Vp, both differ only in the conditions at the start of the process, and based on the PID control method so that the current current value Ap matches the current set value As that is the target value. The process of adjusting the current voltage value Vp is the same.

  After the voltage is raised by the voltage PID adjustment process, the power supply device 9 returns to step Sa1 and continues operation. Thereby, in the power supply device 9, since the voltage present value Vp when applying an alternating voltage to the 1st electrode group 7 and the 2nd electrode group 8 is pulled up, the excessive fall of an electric current value is eliminated.

  On the other hand, if it is determined in step Sa9 that the current voltage value Vp does not satisfy the condition (Vp <Vh), the voltage cannot be raised from the current voltage value Vp. In this case, the power supply device 9 returns to step Sa1 and continues operation without performing any particular processing.

  FIG. 9 shows, as still another embodiment of the present invention, constant power control performed by the power supply device 9 having the same configuration as the embodiment of FIGS. 1 to 5A and 5B.

  When performing constant power control, the power supply 9 is preliminarily set with a power setting value Ks desired as the upper limit of power consumption, an allowable fluctuation range c on the power reduction side with reference to the power setting value Ks, and An allowable fluctuation range d on the power increase side is set in advance. The power supply device 9 is also set with a voltage lower limit value Vl for the AC voltage, and a pulse frequency upper limit value Hh and a pulse frequency lower limit value Hl.

  In this state, the power supply device 9 firstly satisfies the condition (Ks) that the current power value Kp is within the allowable fluctuation range c on the power decrease side or within the allowable fluctuation range d on the power increase side with respect to the power setting value Ks. It is determined whether or not −c ≦ Kp ≦ Ks + d) is satisfied (step Sb1).

  If it is determined in step Sb1 that the current power value Kp satisfies the condition (Ks−c ≦ Kp ≦ Ks + d), the power supply device 9 is set in advance while maintaining the operation state at that time. The determination process in step Sb1 is repeated at a certain sampling period.

  On the other hand, when it is determined in step Sb1 that the current power value Kp does not satisfy the condition (Ks−c ≦ Kp ≦ Ks + d), the power supply device 9 proceeds to step Sb2, and the current power value Kp is Then, it is determined whether or not a condition (Kp> Ks + d) that the allowable fluctuation range d on the power increase side with respect to the power setting value Ks is exceeded is satisfied.

  If it is determined in step Sb2 that the current power value Kp satisfies the condition (Kp> Ks + d), it is necessary to reduce the current power value Kp.

  Therefore, the power supply device 9 proceeds to step Sb3 and determines whether or not a condition that the current voltage value Vp is larger than the voltage lower limit value Vl (Vp> Vl) is satisfied. If it is determined in step Sb3 that the current voltage value Vp satisfies the condition (Vp> Vl), the voltage can be lowered within the range from the current voltage value Vp to the voltage lower limit value Vl. .

  Therefore, when it is determined in step Sb3 that the condition (Vp> Vl) is satisfied, the power supply device 9 proceeds to step Sb4, and matches the current power value Kp with the power setting value Ks that is the target value. A control waveform PID adjustment process for changing the control waveform of the AC voltage applied to the first electrode group 7 and the second electrode group 8 is performed using a PID control technique as a feedback control technique. After the control waveform is changed by the control waveform PID adjustment process, the power supply device 9 returns to step Sb1 and continues operation. Thereby, in the power supply device 9, it is prevented that the power consumption of the power supply device 9 rises excessively by the fall of the electric current and voltage when applying an alternating voltage to the 1st electrode group 7 and the 2nd electrode group 8. .

  On the other hand, if it is determined by step Sb3 that the current voltage value Vp does not satisfy the condition (Vp> Vl), the voltage cannot be lowered from the current voltage value Vp. In this case, the power supply device 9 proceeds to step Sb5 in order to start adjustment of the pulse frequency of the AC voltage applied to the first electrode group 7 and the second electrode group 8.

  In step Sb5, it is determined whether or not a condition (Hm> Hl) that the pulse frequency control value Hm of the AC voltage at that time is larger than the pulse frequency lower limit value Hl is satisfied. If it is determined in step Sa5 that the pulse frequency control value Hm satisfies the condition (Hm> Hl), the pulse frequency control value Hm can be lowered within the range up to the pulse frequency lower limit value Hl. is there.

  Therefore, when it is determined in step Sb5 that the condition (Hm> Hl) is satisfied, the power supply device 9 proceeds to step Sb6, and matches the current power value Kp with the power setting value Ks that is the target value. A frequency PID adjustment process for reducing the pulse frequency control value Hm is performed using the PID control method. After the pulse frequency control value Hm is lowered by the frequency PID adjustment process, the power supply device 9 returns to step Sb1 and continues operation. Thereby, in the power supply device 9, since the pulse frequency when applying an alternating voltage to the first electrode group 7 and the second electrode group 8 is lowered, and the average value of the current values necessary for plasma discharge is lowered, the power supply device The power consumption is reduced by 9.

  If it is determined by step Sb5 that the pulse frequency control value Hm does not satisfy the condition (Hm> Hl), if the pulse frequency control value Hm is further reduced, plasma due to dielectric barrier discharge is generated. It becomes difficult to generate a stable discharge. Therefore, the power supply device 9 proceeds to step Sb7 to stop the control and issue an alarm.

  As a result of the above processing, as described above, the temperature of the processing target gas G existing in the plasma generation region 20 increases, and the processing target gas G containing a specific gas component exists in the plasma generation region 20. The phenomenon that the current value increases can be dealt with by making the power consumption in the power supply device 9 constant by changing the control waveform or lowering the pulse frequency control value Hm.

  In this state, when the phenomenon that causes the increase in the current value such as the temperature increase of the processing target gas G in the plasma generation region 20 or the presence of a specific gas component is improved or eliminated, With the control waveform and the pulse frequency control value Hm after adjustment to suppress the increase in current value, the power consumption of the power supply device 9 may be significantly lower than the power setting value Ks. Therefore, in the constant power control performed by the power supply device 9, the current power value Kp when the AC voltage is applied from the power supply device 9 to the first electrode group 7 and the second electrode group 8 is changed from the power set value Ks as described above. If a drop occurs, restore the drop.

  In view of this point, when it is determined by the determination in step Sb2 that the current power value Kp does not satisfy the condition (Kp> Ks + d), the current power value Kp is equal to the power set value Ks. Since the condition is lower than the allowable power fluctuation range c on the power reduction side (Ks−c> Kp), the process proceeds to step Sb8 to start the process of raising the current power value Kp.

  In step Sb8, it is determined whether or not the pulse frequency control value Hm of the AC voltage at that time satisfies a condition (Hm ≦ Hh) that is equal to or lower than the pulse frequency upper limit value Hh. If it is determined in step Sa8 that the pulse frequency control value Hm satisfies the condition (Hm ≦ Hh), the pulse frequency control value Hm can be raised within the range up to the pulse frequency upper limit value Hh. is there.

  Therefore, when it is determined in step Sb8 that the condition (Hm ≦ Hh) is satisfied, the power supply device 9 proceeds to step Sb6, and the PID is set so that the current power value Kp matches the power set value Ks that is the target value. A frequency PID adjustment process for raising the pulse frequency control value Hm is performed using a control method.

  Note that the frequency PID adjustment processing performed in step Sb6 increases the pulse frequency control value Hm when performed based on the determination processing of step Sb8, while the pulse frequency control value when performed based on the determination processing of step Sb5 described above. Although described as a process for lowering the control value Hm, the PID control method is used so that the current power value Kp matches the power set value Ks that is the target value, with the only difference being the conditions at the start of the process. The process of adjusting the pulse frequency control value Hm based on this is the same.

  After the pulse frequency control value Hm is raised by the frequency PID adjustment process in step Sb6, the power supply device 9 returns to step Sb1 and continues operation. Thereby, in the power supply device 9, since the pulse frequency when applying an alternating voltage to the 1st electrode group 7 and the 2nd electrode group 8 is raised, and the average value of the current value required for plasma discharge is raised, An excessive decrease in the value Kp is eliminated.

  On the other hand, if it is determined in step Sb8 that the pulse frequency control value Hm does not satisfy the condition (Hm ≦ Hh), the pulse frequency control value Hm cannot be further increased.

  Therefore, in this case, the power supply device 9 proceeds to step Sb4 and uses the PID control technique to match the current power value Kp with the power setting value Ks that is the target value. A control waveform PID adjustment process for changing the control waveform of the AC voltage applied to the two electrode group 8 is performed.

  The control waveform PID adjustment process performed in step Sb4 is intended to increase the current power value Kp when performed based on the determination process in step Sb8, while it is performed based on the determination process in step Sb3 described above. In this case, the purpose is to lower the current power value Kp, but both differ only in the conditions at the start of processing, and the PID is set so that the current power value Kp matches the power setting value Ks as the target value. The actual process of adjusting the control waveform based on the control method is the same.

  After the control waveform is changed by the control waveform PID adjustment process, the power supply device 9 returns to step Sb1 and continues operation. Thereby, in the power supply device 9, recovery from a reduced power consumption state of the power supply device 9 is achieved by improving the current and voltage when an AC voltage is applied to the first electrode group 7 and the second electrode group 8.

  FIG. 10 shows still another embodiment of the present invention, in which the current value constant control shown in FIG. 8 is performed by the power supply apparatus 9 having the same configuration as the embodiment of FIGS. 1 to 5A and 5B. 10 shows a case in which a process combining the constant power control shown in FIG. 9 is performed.

  In FIG. 10, a part surrounded by a broken line SA is a process corresponding to the constant current value control of FIG. 8, and the same processing steps as those in FIG. Further, the portion surrounded by the broken line SB is processing corresponding to the constant power control in FIG. 9, and the same reference numerals are given to the same processing steps as in FIG.

  When the processing of the present embodiment is performed, the current setting value As similar to that described with reference to FIG. 8, the allowable fluctuation range a on the current decrease side, and the allowable fluctuation on the current increase side are previously supplied to the power supply device 9. Range b, voltage upper limit value Vh and voltage lower limit value Vl, pulse frequency upper limit value Hh and pulse frequency lower limit value Hl, and power setting value Ks similar to that described in FIG. 9, and allowable fluctuation range c on the power reduction side And an allowable fluctuation range d on the power increase side is set in advance.

  In this state, the power supply device 9 first determines whether or not the current current value Ap satisfies a condition (Ap> As + b) that exceeds the allowable fluctuation range b on the current increase side based on the current set value As. (Step Sc1).

  If it is determined in step Sc1 that the current current value Ap satisfies the condition (Ap> As + b), the power supply device 9 performs the processing from step Sa3 to step Sa7 in the constant current value control shown in FIG. To implement.

  As a result, in the power supply device 9, the current increases due to the temperature rise of the processing target gas G existing in the plasma generation region 20 and the processing target gas G containing a specific gas component existing in the plasma generation region 20. The phenomenon in which the value increases can be dealt with by reducing the current voltage value Vp by the voltage PID adjustment process in step Sa4 or by reducing the pulse frequency control value Hm by the frequency PID adjustment process in step Sa6. . After that, the power supply device 9 returns to step Sc1 and continues operation.

  If neither the voltage PID adjustment process at step Sa4 nor the frequency PID adjustment process at step Sa6 can be performed, the power supply device 9 stops the control and issues an alarm at step Sa7. It is like that.

  On the other hand, when it is determined by the determination in step Sc1 that the current current value Ap does not satisfy the condition (Ap> As + b), the power supply device 9 proceeds to step Sc2, and the current current value Ap is the current set value. It is determined whether or not a condition (As−a> Ap) in which the current fluctuation is smaller than the allowable fluctuation range a on the current decrease side with respect to As is satisfied.

  If it is determined in step Sc2 that the current current value Ap satisfies the condition (As−a> Ap), as in the case where the determination condition in step Sa2 in the constant current value control in FIG. 8 is not satisfied. It is considered that the current current value Ap is lower than the current set value As because the phenomenon that caused the current value to increase is improved or eliminated after the processing of the above-described steps Sa4 and Sa6.

  Therefore, when it is determined in step Sc2 that the condition (As−a> Ap) is satisfied, the power supply device 9 proceeds to step Sc3, where the current power value Kp is on the power reduction side based on the power set value Ks. It is determined whether or not a condition (Ks−c> Kp) that is lower than the permissible fluctuation range c is satisfied. If this condition is satisfied, the processing after step Sa8 shown in FIG. 8 is started.

  Accordingly, the current set value As of the current current value Ap is set to the target by raising the pulse frequency control value Hm by the frequency PID adjustment process at step Sa6 or by raising the voltage current value Vp by the voltage PID adjustment process at step Sa4. Recovery can be achieved.

  In addition, when it is determined that the condition (Ks−c> Kp) is not satisfied by the determination in Step Sc3, the power supply device 9 returns to Step Sc1 and continues the operation.

  Under the condition that the current current value Ap is determined not to satisfy the determination condition in step Sc1 (Ap> As + b), the current current value Ap is further changed to the condition (As−a) by the determination in step Sc2. > Ap) is determined not to satisfy the same condition as when the condition (As−a ≦ Ap ≦ As + b) in step Sa1 in FIG. 8 is satisfied. Therefore, in this case, the power supply device 9 starts not the constant current value control but the same constant power control as shown in FIG.

  In this constant power control, as described with reference to FIG. 9, the temperature of the processing target gas G existing in the plasma generation region 20 rises, and the processing target gas G containing a specific gas component exists in the plasma generation region 20. The phenomenon that the current value rises due to the occurrence of this can be dealt with by stabilizing the power consumption in the power supply device 9 by changing the control waveform or lowering the pulse frequency control value Hm. it can.

  In addition, after the change of the control waveform or the process of lowering the pulse frequency control value Hm, the phenomenon that caused the current value to increase is improved or eliminated, and the current current value Ap is lower than the current set value As. In such a case, recovery by targeting the power set value Ks of the current power value Kp can be achieved by raising the pulse frequency control value Hm or changing the control waveform.

  Therefore, the power supply device 9 has the function of constant current value control as shown in FIG. 8, the function of constant power control as shown in FIG. 9, or the constant current value control and constant power control shown in FIG. According to the gas processing apparatus 1 of the present invention having the function of performing the combined processing, when the combustion exhaust gas of the combustion facility is processed as the processing target gas G, the power supply is changed along with the change in the properties of the processing target gas G. Even if the phenomenon of an increase in the current value in the device 9 occurs, the power consumption of the power supply device 9 can be prevented from rising excessively, and plasma discharge due to dielectric barrier discharge can be stably generated.

  In each of the above embodiments, the gas treatment device 1 of the present invention is arranged in two stages by bringing the first electrode group 7 and the second electrode group 8 into contact with the frame 10 and bringing the electrodes 2a and 2b into contact with each other. As shown in FIG. 11A, the first electrode group 7 and the second electrode group are arranged in two layers on the frame 10 in the same manner as described above. It is also possible to adopt a configuration in which a plurality of sets of 8 are provided at a certain interval in the axial direction of the frame (two sets are shown in the figure).

  Furthermore, as schematically shown in FIG. 11 (b), the gas processing apparatus 1 of the present invention contacts the frame 10 with the first electrode group 7 and the second electrode group 8, and the electrodes 2a and 2b with each other. In this state, a configuration may be adopted in which a plurality of stages (in the figure, four stages are shown) that are more than two stages are stacked and attached.

  In FIGS. 11A and 11B, the configuration other than the inside of the frame 10 and the description of the electrode deflection displacement prevention mechanism 12 are omitted.

  In addition, the present invention is not limited to the above-described embodiment, and the adjacent electrodes 2a, the distance between the electrodes 2b, and the opening size of the gas passage 21 formed thereby are shown in the drawings. This is for convenience, and does not reflect actual dimensions.

  The number of the electrodes 2 a and 2 b in the first electrode group 7 and the second electrode group 8 may be arbitrarily set according to the size of the cross section of the gas flow path 11 of the frame 10.

  Moreover, when the cross section of the gas flow path 11 is a rectangle, the longitudinal direction dimension and arrangement number of the electrode 2a and the electrode 2b may differ.

  If the electrodes 2a of the first electrode group 7 can be connected in parallel, the shape of the terminal 13a may be set freely. Similarly, the shape of the terminal 13b may be freely set as long as the electrodes 2b of the second electrode group 8 can be connected in parallel.

  The gas treatment apparatus 1 of the present invention is a gas containing a component desired to be deodorized or detoxified by dielectric barrier discharge plasma discharge, for example, gas discharged from a process involving heating such as casting or forging. In addition, the present invention may be applied to the processing of any processing target gas G other than the combustion exhaust gas of the combustion facility. Further, the gas processing apparatus 1 of the present invention is applicable not only to high temperatures but also to processing of the processing target gas G at any temperature such as room temperature.

  In the cleaning devices 23 and 23a, the number of spray nozzles 25 provided in the header pipe 28 may be freely changed. Furthermore, the drive device 30 in the cleaning device 23 employs any type of drive device other than those shown in the drawings as long as the header pipe 28 and the injection nozzle 25 can be reciprocated along the longitudinal direction of the guide rail 27. Also good.

  If the gas component of the gas G to be processed is a gas component that does not cause a deposit that causes a dielectric action on the electrodes 2a and 2b even if the gas component is processed by plasma discharge by dielectric barrier discharge, the cleaning device 23 is used. , 23a may be omitted.

  Further, when the temperature of the processing target gas G is around room temperature and the thermal expansion generated in the frame 10 and the cover 31 when the processing target gas G is processed is slight, the frame 10 is removed from the cleaning device frame 24. Or you may make it connect directly to the duct which distribute | circulates the process target gas G. FIG.

  In the embodiment shown in FIGS. 1 to 5A and 5B, the electrode deflection displacement prevention mechanism 12 may be provided with the urging means 34 in the embodiment shown in FIG.

  In the process of constant current value control shown in FIG. 8, constant power control shown in FIG. 9, and combination of constant current value control and constant power control shown in FIG. 10, the voltage (current voltage value Vp) is adjusted in step Sa4. As the feedback control method used when adjusting the pulse frequency control value Hm in steps Sa6 and Sb6 and adjusting the control waveform in step Sb4, it is preferable to use the PID control method, but any feedback other than the PID control method is used. A control method may be used.

  FIG. 10 shows a processing procedure for determining whether or not the start condition for constant current value control is satisfied, and determining whether or not the start condition for constant power control is satisfied when the condition is not satisfied. However, first, it is determined whether or not the start condition for constant power control is satisfied, and if that condition is not satisfied, a processing procedure is performed for determining whether or not the start condition for constant current value control is satisfied. May be.

  Of course, various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Gas processing apparatus 2a, 2b electrode 3 Dielectric 4 Conductor 7 1st electrode group 8 2nd electrode group 9 Power supply device 10 Frame 11 Gas flow path 12 Electrode bending displacement prevention mechanism 13a, 13b Terminal 22a, 22b Electrode support member 23 , 23a Cleaning device G Gas to be treated

Claims (6)

An electrode is formed by attaching a conductor to the inner surface of a straight pipe-shaped dielectric,
A first electrode group in which a plurality of electrodes extending in one direction are arranged in parallel at a certain interval, and a conductor of each electrode is connected in parallel to a terminal;
A plurality of electrodes extending in a direction orthogonal to each electrode of the first electrode group are arranged in parallel at a certain interval, and a conductor of each electrode is connected in parallel to another terminal. Two electrode groups;
A power supply device for applying an alternating voltage to each terminal of each electrode group, and a cylindrical frame with the inside as a flow path for the gas to be processed,
In the gas flow path inside the frame, each electrode of the first electrode group and each electrode of the second electrode group are stacked and arranged in a plurality of stages in contact with each other so as to form a lattice shape. The base end portion of each electrode of each electrode group is fixed to the side wall of the frame, and the tip end portion of each electrode of each electrode group is held so as to be displaceable in the longitudinal direction. Gas processing equipment. Displacement due to bending deformation of each electrode in the frame by sandwiching each electrode of each electrode group stacked in the gas flow path inside the frame by a pair of electrode support members from both sides in the axial direction of the frame The gas processing apparatus according to claim 1, further comprising an electrode deflection displacement prevention mechanism for preventing the occurrence of the problem. The gas processing apparatus according to claim 1, further comprising a cleaning device that performs blow cleaning on a portion of each electrode group that is disposed in the frame in each electrode. The power supply device
Compare the current value and the preset current setting value,
When the current current value exceeds the preset allowable fluctuation range on the current increase side with respect to the current setting value,
When the AC voltage is applied to the first electrode group and the second electrode group by the feedback control method so that the current current value matches the current setting value when the current voltage value is larger than the preset voltage lower limit value Adjust the current voltage value of
The current value constant control function for adjusting the pulse frequency by feedback control so that the current current value matches the current set value when the current voltage value is equal to or lower than the voltage lower limit value. The gas treatment device according to any one of 3. The power supply device
Compare the current power value with the preset power setting value,
When the current power value exceeds the preset allowable range on the power increase side with respect to the power setting value,
When the current voltage value is larger than the preset voltage lower limit value, control of the AC voltage applied to the first electrode group and the second electrode group by the feedback control method so that the current power value matches the power set value Perform processing to change the waveform,
The power constant control function for adjusting the pulse frequency by feedback control so that the current power value matches the power setting value when the current voltage value is equal to or lower than the voltage lower limit value. The gas treatment device according to any one of the above. The power supply device
Compare the current value and the preset current setting value,
When the condition that the current current value exceeds the preset allowable fluctuation range on the current increase side with respect to the current setting value is satisfied,
When the AC voltage is applied to the first electrode group and the second electrode group by the feedback control method so that the current current value matches the current setting value when the current voltage value is larger than the preset voltage lower limit value Adjust the current voltage value of
When the current voltage value is less than or equal to the voltage lower limit value, a current value constant control function that adjusts the pulse frequency by feedback control so that the current current value matches the current setting value;
The current current value is within an allowable fluctuation range on the current decrease side and the current increase side set in advance with respect to the current set value, and the current power value is on the power increase side set in advance with respect to the power set value. When the allowable runout range is exceeded,
When the current voltage value is larger than the preset voltage lower limit value, control of the AC voltage applied to the first electrode group and the second electrode group by the feedback control method so that the current power value matches the power set value Perform processing to change the waveform,
The power constant control function for adjusting the pulse frequency by feedback control so that the current power value matches the power set value when the current voltage value is equal to or lower than the voltage lower limit value. The gas treatment device according to any one of 3.

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