WO2003068382A1

WO2003068382A1 - Discharge device

Info

Publication number: WO2003068382A1
Application number: PCT/JP2003/001658
Authority: WO
Inventors: Shigeru Tamaru; Hideo Kimura
Original assignee: Furrex Co., Ltd.
Priority date: 2002-02-15
Filing date: 2003-02-17
Publication date: 2003-08-21
Also published as: JPWO2003068382A1; AU2003211327A1

Abstract

A discharge device comprises an outer electrode having a gas inlet at one end and a gas outlet at the other end, an inner electrode disposed inside the outer electrode, gas circulating means for circulating a gas to be processed through the space between the inner and outer electrodes, and a power supply for applying a discharge voltage between the inner and outer electrodes while circulating the gas through the space, characterized in that the space includes an annular discharging region defined by an intermediate portion in the axial direction of the outer periphery of the inner electrode and an intermediate portion in the axial direction of the inner periphery of the outer electrode and an annular discharge spreading region which is an annular space defined downstream form the discharging region by the outer periphery of the inner electrode and the inner periphery of the outer electrode and in which the gap between the inner and outer electrodes in the annular space is larger than the gap between the inner and outer electrodes in the discharging region, and the gap of the discharge spreading region is set so that discharge may occur in the discharging region when a predetermined discharge voltage is applied between the outer and inner electrodes while causing the gas to flow from the gas inlet to the gas outlet and the discharge may spread into the discharge spreading region and be sustained.

Description

Itoda »

Technical field

The present invention relates to a discharge device, and more particularly to a discharge device used for decomposing a gas to be treated by the action of electric discharge or synthesizing a chemical substance from the gas to be treated. Background art

Conventionally, a pair of electrodes in the above-described discharge device has, for example, a minus one-dollar shape, and generates an arc discharge between the tip portions of both electrodes.

However, according to the conventional discharge device, since the arc has a substantially linear shape, the amount of the gas to be treated coming into contact with the arc per unit time is small, and as a result, a synthesis reaction or the like does not occur. However, even if they occurred, there was a problem that their progress was extremely slow.

Accordingly, the present applicant has firstly provided a discharge reactor having a cylindrical outer electrode having an inner peripheral surface as a discharge surface, and a cylindrical inner electrode having an outer peripheral surface as a discharge surface facing the discharge surface, A discharge device having gas supply means for supplying a gas to be treated under pressure into a cylindrical annular passage between both discharge surfaces, and a power supply device for applying a discharge voltage between an outer electrode and an inner electrode has been proposed (see Japanese Patent Application Laid-Open 0 0 2-3 5 5 5 4 8).

As described above, when a discharge voltage is applied between the cylindrical outer electrode and the cylindrical inner electrode while supplying the gas to be processed into the cylindrical gap between the two discharge surfaces under pressure, a discharge is generated over substantially the entirety of the two discharge surfaces. I do. This makes it possible to decompose the gas to be treated, synthesize it using the gas, etc., and to efficiently proceed with the decomposition.

The present applicant has decomposed the gas to be treated by using the above-described apparatus, and as a result, I felt the need to further improve the processing capacity of the equipment.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a discharge device with further improved processing capacity for a gas to be processed. Disclosure of the invention

To achieve the above object, the present invention provides an outer electrode having a gas inlet at one end and a gas outlet at the other end, an inner electrode disposed inside the outer electrode, the inner electrode and the outer electrode. A gas flowing means for flowing the gas to be treated in the space between the electrodes, and a power supply for applying a discharge voltage between the inner electrode and the outer electrode while the gas to be treated is flowing in the space. A discharge device comprising: an annular discharge generating device defined by an intermediate portion of the outer peripheral surface of the inner electrode in the axial direction and an intermediate portion of the inner peripheral surface of the outer electrode in the axial direction. And an annular space defined by an outer peripheral surface of the inner electrode and an inner peripheral surface of the outer electrode on the downstream side of the discharge generation region, wherein a gap between the inner and outer electrodes of the annular space is Discharge generation area A discharge spreading area that is larger than a gap between the inner and outer electrodes in the process, wherein the gas to be treated flows between the gas inlet and the gas outlet while the gas to be treated flows between the outer electrode and the inner electrode. When the predetermined discharge voltage is applied, the discharge in the discharge generation region is generated, and the gap in the discharge spread region is set so that the discharge spreads to the discharge spread region and continues. is there. With such a configuration, the gas to be processed having passed through the narrow discharge generation region flows so as to be opened in the wide discharge spread region. The discharge induced in the flow of the gas to be treated and generated in the discharge generating region spreads to the discharge spreading region. For example, if the discharge in the discharge generation area is an arc discharge, the positive column in the arc discharge generated in a straight line extends in an arc or horizontal “U” shape in the discharge spread area according to the flow of the gas to be treated. To sustain the arc discharge. Also, according to the above configuration, for example, The gap of the discharge spreading area can be set such that the volume of the discharge spreading area is larger than the volume of the discharge generating area while keeping the shape of the inner peripheral surface of the outer electrode constant. When the volume and the discharge spread area are formed as described above, the amount and time of exposure of the gas to be treated to the discharge are further increased. Processing capacity can be further improved.

Preferably, the outer electrode is an electrode that concentrically surrounds the inner electrode so that the discharge generated in the discharge generation region spreads and continues to the discharge spreading region. It is provided with a disc-shaped portion forming a generation region, and a truncated conical portion having a large diameter end connected to the gas outlet side end of the disc-shaped portion to form the discharge spreading region. Preferably, the axial length of the truncated conical portion is at least three times the axial / 锒 length of the disc-shaped portion. Thus, the gap between the inner and outer electrodes in the discharge spreading region can be set so as to gradually increase from the discharge generating region to the gas outlet. Accordingly, the electric field formed by the predetermined discharge voltage gradually decreases from the discharge generation region to the gas outlet. Therefore, a situation that occurs when it becomes difficult for the discharge in the discharge generating region to spread to the discharge spreading region due to, for example, a steep change in the electric field or the like is suppressed. In addition, the gas to be treated flows so as to spread in a direction orthogonal to the axial direction from the discharge generation region to the gas outlet according to the expansion of the gap between the outer electrodes in the discharge spreading region. Induced by such a flow, the discharge in the discharge generation region easily spreads to the radio wave transmission region.

Also preferably, the inner electrode further includes a columnar portion connected to a small-diameter end of the truncated conical portion provided in the inner electrode. Thus, the gap between the inner and outer electrodes in the discharge spreading area can be set to be constant in the cylindrical portion. Accordingly, the electric field formed by the predetermined discharge voltage also becomes constant in the column, and the discharge in the column easily spreads in the axial spring direction.

Still more preferably, the axis of the outer peripheral surface of the inner electrode in the discharge generation region The distance between the middle part in the linear direction and the middle part in the axial direction of the inner peripheral surface of the outer electrode is 5 ram to 25 mm. As a result, when a predetermined discharge voltage is applied between the inner electrode and the outer electrode, an arc discharge, a glow discharge, or a glow discharge immediately before the glow discharge changes to an arc discharge in the discharge generation region. It is possible to generate a discharge in the transition region from to the arc discharge.

Also preferably, the axial length of the discharge generating region is 2 mm to 10 mm. The discharge generation region having such a length in the axial direction gives the gas to be treated a conduit resistance for the gas to be treated to be efficiently opened in the discharge spread region. In other words, the discharge effort region, together with the discharge spread region, can fulfill the function of, for example, a throat for the gas to be treated. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a system diagram of a discharge apparatus in which a laughing gas decomposition experiment was performed using a discharge reactor according to an embodiment of the present invention.

FIG. 2 is a fragmentary front view of a discharge reactor according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along line 3-3 in FIG.

FIG. 4 is a fragmentary front view of a main part of a discharge reactor according to another embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

In the discharge device 1 shown in FIG. 1, a gas circulation device 3 as gas distribution means is attached to a cylindrical discharge reactor 2. This device 3 has a first conduit 6 connecting between a gas inlet tube 4 at one end of the discharge reactor 2 and a gas outlet tube 5 at the other end. From the side of the outlet tube 5, a transparent box 8 with a fan 7 placed at an intermediate position inside, a rubber for adjusting the pressure in the reaction path such as in the first conduit 6 A pressure regulator 9 and a gas adsorber 10 are provided. The transparent box 8 is made of a synthetic resin, for example, polymethyl methacrylate. A bypass 11 bypassing the gas adsorber 10 is connected to the first conduit 6 via first and second three-way valves 12 and 13. Further, an AC power supply device 16 as a power supply device is connected to both connection terminals 14 and 15 on the outer peripheral portion of the discharge reactor 2 via conductors 97 and 98.

In order to supply the gas to be processed to the gas circulation device 3, the gas supply device 17 for the gas to be processed is provided between the gas inlet cylinder 4 and the first three-way valve 12 via the second conduit 18 via the first conduit 6. The first on-off valve 19, the third three-way valve 20, and the flow meter 21 are sequentially connected to the second conduit 18 from the discharge reactor 2 side. In the first conduit 6, a check valve 21 for preventing gas flow to the valve 12 side is provided between the connection portion a with the second conduit 18 and the first three-way valve 12. On the other hand, on the gas outlet cylinder 5 side, the inlet side of the third conduit 23 is connected to the first conduit 6 via the fourth three-way valve 22, and the outlet side is connected to the fourth three-way valve 22 of the first conduit 6. Connected downstream. In the third conduit 23, in order from the fourth three-way valve 22 side, a check valve 24 that blocks gas flow to the valve 22 side, a gas concentration measurement device 25, and the measurement device 25 side A check valve 26 is provided to prevent gas flow into the pump. In the first conduit 6, a check valve 27 for preventing gas flow to the valve 22 between the connection b of the third conduit 23 with the outlet side of the third conduit 23 and the fourth three-way valve 22 is provided. Is done.

In order to detect the concentration of gas discharged from the discharge reactor 2 in the reaction process, the fourth conduit 2 is connected between the transparent tube 8 and the connection part b of the first conduit 6 with the outlet side of the third conduit 23. 8 is connected to the inlet side, and the outlet side is connected to a gas concentration measuring device 25. In this case, the outlet S of the third conduit 23 between the gas concentration measuring device 25 and the first conduit 6 is shared as the outlet S of the gas after the concentration measurement. In the fourth conduit 28, a second on-off valve 29 is provided between its connection part c with the first conduit 6 and the gas concentration measuring device 25.

In the discharge reactor 2 shown in Figs. 2 and 3, a gas inlet 45 is provided at one end and a gas outlet is provided at the other end. Electrically insulating first and second end plates 48, 49 having the same shape are applied to both annular end faces of the cylindrical outer electrode 47 having the ports 46, respectively, and the plurality of bolts 50 are used. It is attached to its outer electrode 47. The outer electrode 47 has a large-diameter hole 51 on the first end plate 48 side, a small-diameter hole 52 on the second end plate 49 side, and a taper connecting both holes 51, 52. It has a hole 53, and the connecting portion between the tapered hole 53 and the large and small diameter holes 51, 52 has an arc shape. The inner peripheral surfaces of the large and small diameter holes 51, 52 and the tapered hole 53 are mirror-finished.

In the outer electrode 47, the upper electrode 54 is held between the first and second end plates 48, 49 and is arranged concentrically with the outer electrode 47, and the inner and outer electrodes 47, 54 A space S is formed between them. The inner electrode 54 has a disc-shaped portion 55 located at an intermediate portion in the axial direction, and first and second ends each having a large-diameter end connected to a gas inlet 45 side end and a gas outlet 46 side end. (2) The frusto-conical portions 56, 57, and the first shaft portion 58, which projects from the small-diameter end face of the first frusto-conical portion 56 and is smaller than that, and continues to the small-diameter end of the second frusto-conical portion 57. In addition, it has a short cylindrical portion 59 having the same diameter as that, and a second shaft portion 60 projecting from the end face of the short cylindrical portion 59 and having a smaller diameter. These components 55, 56,

57, 58, 59, 60 are coaxial and their axes coincide with those of the outer electrode 47. The first shaft portion 58 is fitted into a through hole 61 coaxial with the outer electrode 47 formed on the first end plate 48, and the small-diameter end face of the first truncated cone portion 56 is the first end plate. 4 Contact 8 In the outer electrode 47, the first truncated conical portion 56 and the disc-shaped portion 55 are located in the large-diameter hole 51, and the second truncated conical portion 57 is a large-diameter hole 51, tapered. The hole 53 and the small-diameter hole 52 are located within the small-diameter hole 52, and the short cylindrical portion 59 is located within the small-diameter hole 52. The second shaft portion 60 has a through hole coaxial with the outer electrode 47 formed on the second end plate 49.

6, and the end surface of the short cylindrical portion 59 abuts on the second end plate 49. The disc-shaped portion 55, the first and second truncated conical portions 56, 57, and the short cylindrical portion 59 are mirror-finished. The inner and outer electrodes 47, 54, the outer and inner surfaces in the axial direction of the outer surface are brought closer. In the embodiment, the outer peripheral surface of the disk-shaped portion 55 and the vicinity of the tapered hole 53 of the large diameter hole 51 are located When the peripheral surfaces are brought closer to each other, an annular arc discharge generation region A1 is formed between them 55 and 51. The arc discharge generation area Ai is connected to the end on the gas outlet 46 side, and the interval between the inner and outer electrodes of the inner and outer electrodes 47 and 54 is formed to be wider than the arc discharge generation area Ai. The formed cylindrical arc discharge spreading area A ₂ is, in the embodiment, a second truncated conical portion 57 and a short cylindrical portion 59 of the inner electrode 54, and a part of the large diameter hole 51 of the outer electrode 47, It is formed in cooperation with the tapered hole 53 and the small diameter hole 52. That is, the arc discharge generation area A1 and the arc discharge propagation area A2 exist in the space S.

An AC voltage of approximately 100 kV or less is applied between the inner and outer electrodes 54 and 47 for a discharge distance Ds between the outer peripheral surface of the disk-shaped portion 55 and the outer peripheral surface of the large-diameter hole 51 and the peripheral surface. In this case, 5 mm ≤ D s ≤ 25 n ™. In the example, Ds = 5 mni was set in order to apply an AC voltage of 7 to 10 kV between the inner and outer electrodes 54 and 47 as described later. When an AC voltage of 100 kV or more is applied between the inner and outer electrodes 54 and 47, Ds is preferably about 25 Omm or less.

In the present embodiment, arc discharge spillover area A ₂ is the arcing area A _t over the gas outlet tube 5 has a discharge distance described below. The discharge distance between the outer peripheral surface of the second truncated conical portion 57 of the inner electrode 54 and the inner peripheral surface of the large-diameter hole 51 of the outer electrode 47 is the discharge distance of the arc discharge generation region A (D s) about 1 to 2 times. The discharge distance between the outer peripheral surface of the second truncated conical portion 57 of the inner electrode 54 and the inner peripheral surface of the tapered hole 53 of the outer electrode 47 is about 2 to 3 times Ds. . The discharge distance between the outer peripheral surface of the second truncated conical portion 57 of the inner electrode 54 and the inner peripheral surface of the small-diameter hole portion 52 of the outer electrode 47 is approximately 3 to 4 times Ds. . The discharge distance between the outer peripheral surface of the short cylindrical portion 59 of the inner electrode 54 and the inner peripheral surface of the small-diameter hole portion 52 of the outer electrode 47 is constant, and is about four times as large as Ds. The axial length of the second truncated conical portion 57 is at least three times the axial length of the disc-shaped portion 55. In the present embodiment, the axial length of the second truncated conical portion 57 is about nine times the axial length of the disc-shaped portion 55. Further, the length of the disc-shaped portion 55 in the axial direction is 2 mm to 1 O mm. In the present embodiment, the length of the disc-shaped portion 55 in the axial direction is about 4 mm.

In the first and second end plates 48, 49, a plurality of small holes 63, 64 are formed around the through holes 61, 62 at regular intervals (see Fig. 3). 4 communicates with the outside electrode 47.

On the outer surface side of the first end plate 48, a flange portion 66 at one end of the gas inlet tube 4 is attached to the first end plate 48 with a plurality of bolts 67. It communicates with each small hole 63 of one end plate 48. Also, on the outer surface side of the second end plate 49, a flange portion 69 at one end of the gas outlet tube 5 is attached to the second end plate 49 by a plurality of bolts 70. Communicates with each small hole 64 of the second end plate 49. One of the connection terminals 14 has a rod shape, and is inserted into the first end plate 48 through an elongated hole 73 formed so as to pass from the outer peripheral portion thereof between the adjacent small holes 63. The other connecting terminal 15 is screwed on the outer peripheral portion of the outer electrode 47 at a position bisected by the bus bar on the one shaft portion 58. In the figure, reference numeral 77 denotes a sealing ring.

The outer electrode 47 and the inner electrode 54 are made of stainless steel, for example, JISSUS304. However, the inner electrode 54 can be made of an A1 alloy, for example, JIS5052. The first and second end plates 48, 49 are made of synthetic resin, for example, cloth-filled bakelite, and gas inlets having flange portions 66, 69, and gas outlet tubes 4, 5 are made of A1 alloy. For example, the first and second end plates 48, 49 composed of JIS5052 can be composed of ceramics, and the gas inlet and gas outlet cylinders 4, 5 can be composed of stainless steel. is there. Gas adsorber 10 is used as adsorbent It has an activated carbon fiber filter (manufactured by Nippon Riki Inol Co., Ltd., trade name: Kynol ACN305-15) with a density of 180 g Zm ³ The bulk density of the activated carbon fiber filter in the gas adsorber 10 is suitably from 90 to 180 g / m ³ .

Next, an example in which the discharge device 1 is applied to the treatment of laughter (nitrous oxide 亜 2θ) which is a medical anesthetic gas as a gas to be treated will be described. In this case, the gas supply device 17 has a function of supplying a mixed gas composed of laughter and air, and a function of supplying only laughter.

A. Discharge treatment of laughter and gas sampling

(a) The first on-off valve 19 was opened, and the gas supply unit 17 and the discharge reactor 2 were connected by switching the third three-way valve 20. Further, the gas outlet tube 5 of the discharge reactor 2 is communicated with the transparent box 8 by switching the fourth three-way valve 22, and the inlet and outlet of the gas adsorber 10 are switched by switching the first and second three-way valves 12, 13. The side was opened and the bypass 11 was closed. The second on-off valve 29 is in a closed state.

(b) A gas mixture consisting of laughter of 15 V o 1% and air of 85 V o 1% is supplied to the discharge reactor 2 from the gas supply unit 17 and the supply amount of the mixed gas is reduced to 30 L. When it reached, the supply of the mixed gas from the gas supply unit 17 was stopped, and the first on-off valve 19 was closed.

(c) a fan 7 is operated by blowing rate 1. lm ³ Zm in, discharging a mixed gas reactive応器2 → fourth three-way valve 22 → the check valve 27 → the transparent box 8 → pressure adjuster 9 → second Three-way valve 1 3 → Gas adsorber 10 → First three-way valve 12 → Check valve 2 1−Circulate in the path of discharge reactor 2 to allow the mixed gas to flow through the space S between the inner and outer electrodes 47 and 54. Was.

(d) A high discharge voltage of 7 to: LO kV, 30 mA, 33 kHz was applied to the inner and outer electrodes 47 and 54 by the AC power supply 16. Accordingly, in a state where the mixed gas is flowing in the space S between the inner and outer electrodes 47 and 54, in the disc-shaped portion 55 of the inner electrode 54 and the large-diameter hole portion 51 of the outer electrode 47 surrounding the same. Arc discharge occurs in the inner circumference, that is, in the arc discharge generation area, and the arc is generated by the flow of the mixed gas. Along the second frusto-conical portion 57 and the short cylindrical portion 59, and then the arc discharge spreading area A2 was filled with the arc. Specifically, the positive column generated in a straight line in the arc discharge generation region A i extended in an arc or a horizontal “U” shape in the arc discharge propagation region A ₂ , and such a phenomenon continued. However, such extension of the positive column is believed to occur are induced in the gas mixture flowing as opened in a narrow arc generation region through the A wide arcing spread area A _2. Here, the second on-off valve 29 was opened, and the concentration of laughter was measured every 10 minutes after the start of discharge.

Table 1 shows the results of measuring the concentration of laughter.

【table 1】

As is clear from Table 1, it can be seen that the entire amount of laughter was decomposed in a short time of 60 minutes after the start of discharge. In the gas adsorber 10, NO and NO 2 generated by the decomposition of laughter are adsorbed.

B. Resolution for laughter

[Example I] B- 1. Discharge treatment of laughter

(a) The first on-off valve 19 was opened, and the gas supply device 17 and the discharge reactor 2 were connected by switching the third three-way valve 20. Further, by switching the fourth three-way valve 22, the gas outlet tube 5 of the discharge reactor 2 is communicated with the gas concentration measuring device 25, and by switching the first and second three-way valves 12, 13, the gas adsorber is switched. The entrance and exit sides of 10 were opened, and the bypass 11 was closed. The second on-off valve 29 is in a closed state.

(b) 100 V o 1% of laughter was supplied from the gas supplier 17 to the discharge reactor 2, and the laughter concentration reached the highest measured value with the gas concentration meter 25, and then the supply was continued. When the measured value did not increase even after continuing, the supply of laughter from the gas supply device 17 was stopped, and the first on-off valve 19 was closed. Further, by switching the fourth three-way valve 22, the gas outlet tube 5 of the discharge reactor 2 was connected to the transparent box 8 via the valve 22 and the check valve 27. In this case, the gas in the reaction path such as the discharge reactor 2 and the gas circulation device 3 is 81 V o 1% laughter, 3.7 V o 1% oxygen, and 13.9 V o 1. /. It was a mixed gas consisting of nitrogen and the remaining undetectable gas. These oxygen, nitrogen and undetectable gases are residual gases in the reaction path.

(c) Operate the fan 7 at the air flow rate of 1.lms / in i η, and discharge the mixed gas from the discharge reactor 2 → 4th three-way valve 2 2 → check valve 2 7 → transparent box 8 → pressure regulator 9 —Circulate in the path of the second three-way valve 1 3 → gas adsorber 10 → first three-way valve 12 → check valve 2 1 → discharge reactor 2 and the space S between the inner and outer electrodes 47, 54 Was passed through the mixed gas.

(d) A high discharge voltage of 7 to 10 kV, 30 mA, 33 kHz was applied to the inner and outer electrodes 47 and 54 by the AC power supply device 16. Thus, in a state where the mixed gas is flowing in the space S between the inner and outer electrodes 47 and 54 as described above, the size of the disk-shaped portion 55 of the inner electrode 54 and the outer electrode 47 surrounding it is increased. An arc discharge is generated between the inner peripheral portion of the diameter hole portion 51, that is, in the arc discharge generation region Ai, and the arc is formed along the flow of the mixed gas around the second truncated conical portion 57 and the short cylindrical portion 59. Spill over, that After arc discharge spread area A2 was filled with arc. Specifically, the positive column force generated in a straight line in the arc discharge generation region A extended in an arc shape or a horizontal “U” shape in the arc discharge spread region A ₂ , and such a phenomenon continued. However, such extension of the positive column is believed to occur are induced in the gas mixture flowing as open at a narrow pass through the arcing region A wide electrical arc spreading region A _2.

(e) The discharge treatment is performed for 10 minutes after the start of the discharge, then the operation of the fan 7 is stopped, and the application of the high discharge voltage to the outer electrodes 47 and 54 by the AC power supply 16 is stopped. At a position X in the conduit 6 between the first three-way valve 12 and the check valve 21, the gas in the reaction path I was collected in the Tedlar bag via the conduit. This concentration causes a negative pressure in the reaction path, but the internal pressure in the reaction path is adjusted to a positive pressure by the pressure regulator 9.

B— 2. Gas analysis

(a) With respect to the collected gas, the NOx concentration and the NO concentration were measured in accordance with the JIS B 7953 chemiluminescence method, and then the NOx concentration minus the NO concentration was subtracted to obtain the NO2 concentration.

Table 2 shows the concentration of NO X in the collected gas.

[Table 2]

(TD) The concentration of laughter was measured using a CAPNO PMAC ULTI MA respiratory gas analyzer (manufactured by Dedex Omega) for the collected gas. When the oxygen concentration and the nitrogen concentration were measured in accordance with the Tograph (GC-TCD) method, the results in Table 3 were obtained.

[Table 3]

According to Tables 2 and 3, laughter was decomposed by the discharge treatment to 12 V o 1% (120,000 ppm), and NO + NQ2 of 5,200 ppm was generated.N2〇 → NO + N〇2 decomposition reaction of (5, 200Z120, 000) X 100 = 4. 3% occurs, the oxygen concentration and the fact that the nitrogen concentration is increasing, New ₂ 0 → decomposition reaction of New ₂ + .theta.2 100% — 4.3% == 95.7% occurred. When the Νθ2 concentration is high, the inside of the transparent box 8 changes color to almost reddish brown due to the Ν2 concentration, but the above phenomenon was not observed in this measurement.

When the arc discharge spreading area A2 is formed in the discharge reactor 2 as described above, the laughter can be decomposed mainly by a single substance and harmless oxygen and nitrogen by improving its decomposition ability. This has the effect of facilitating the treatment of cracked gas.

[Example 1D]

Tables 4 and 5 show that in Fig. 1, the first and second three-way valves 12 and 13 were switched so that the bypass 11 of the first conduit 6 was in communication and the inlet and outlet sides of the gas adsorber 10 were closed. Except for this, the results of gas analysis when laughter discharge treatment was performed in the same manner as in Example I are shown, and correspond to Tables 2 and 3, respectively. [Table 4]

Concentration (p p m)

NO x 20000

NO 4700

NO2 1 5000

[Table 5]

In Table 4, the value of N〇x does not match the value of NO + N02 due to the fact that compounds other than NO and NO 2 are generated in the decomposition of NOx. In this case, 78% of the decomposition reaction of Ν2θ → Ν ₂ + θ2 occurred, and 22% of the decomposition reaction of Ν2θ → Ν Ο + ΝΟ2 occurred.

Comparing Example I with Example I, Example I has a higher rate of decomposition of laughter. From this, it can be said that in order to enhance the decomposition of laughter, it is better to remove ΝΟ and Νθ2 generated by the decomposition reaction with the gas adsorber 10.

Although the preferred embodiments of the present invention have been described above, the embodiments of the present invention described above are intended to facilitate understanding of the present invention, and do not limit the present invention. .

The discharge device 1 according to the above-described embodiment is not limited to decomposition of laughter, and can be applied to, for example, synthesis of NO 2 using air nitrogen, decomposition of NOx, decomposition of CO 2, and the like. For example, in order to efficiently synthesize N0 _2, similar to the above, the discharge generation region and Discharge in the discharge spread area A ₂ good arcing. On the other hand, for example, in order to decompose MO efficiently while suppressing the generation of NO ₂ in NO x, the discharge in the discharge generation region and the discharge spread region A ₂ is changed from a single discharge to an arc Discharge in the transition region from a single discharge to an arc discharge just before the discharge occurs.

The outer electrode 47 in the above-described embodiment has a large-diameter hole 51 on the first end plate 48 side, a small-diameter hole 52 on the second end plate 49 side, It has a tapered hole 53 connecting between 51 and 52, but is not limited to this. For example, as shown in FIG. 4, the through-hole of the outer electrode 47 ′ may be an equal-diameter hole having the same inner diameter as the inner diameter of the large-diameter hole 51 ′. In this case, the gap between the outer peripheral surface of the inner electrode 54 and the inner peripheral surface of the outer electrode 47 in the discharge region A ₂ shown in FIG. 4 should be as small as possible with respect to the gap shown in FIG. The axial length of the second truncated conical portion 57 ′ shown in FIG. 4 is approximately 15 times the axial length of the circular portion 55. Here, in FIG. 4, the same components as those in FIG. 2 are denoted by the same reference numerals. Industrial applicability

According to the present invention, it is possible to efficiently carry out the decomposition of laughter, the synthesis of NO 2 using air nitrogen, the decomposition of NO x, the decomposition of CO 2, etc. It is possible to provide a simple discharge device.

Claims

The scope of the claims

1. an outer electrode having a gas inlet at one end and a gas outlet at the other end, and an inner electrode disposed inside the outer electrode,

Gas flow means for flowing the gas to be treated in a space between the inner electrode and the outer electrode,

A power supply device for applying a discharge voltage between the inner electrode and the outer electrode while the gas to be processed flows in the space;

A discharge device comprising:

The space is

An annular discharge generation region defined by an axially intermediate portion of the outer peripheral surface of the inner electrode and an axially intermediate portion of the inner peripheral surface of the outer electrode; An annular space defined by an outer peripheral surface of an inner electrode and an inner peripheral surface of the outer electrode, wherein a gap between the inner and outer electrodes in the annular space is formed between the inner and outer electrodes in the discharge generation region. Including a discharge spreading area that is larger than the gap,

When the predetermined discharge voltage is applied between the outer electrode and the inner electrode while allowing the gas to be processed to flow from the gas inlet to the gas outlet, a discharge is generated in the discharge generation region. The discharge device according to claim 1, wherein the gap is set in the discharge spreading region so that the discharge spreads to the discharge spreading region and continues.

2. The outer electrode is an electrode that concentrically surrounds the inner electrode, and the inner electrode is formed in a circular shape so as to form the disc-shaped portion forming the discharge generation region and the discharge spreading region. 2. The discharge device according to claim 1, further comprising a frusto-conical portion having a large-diameter end connected to the gas outlet side end of the plate portion.

3. The inner electrode according to claim 2, wherein an axial length of the truncated conical portion of the negative electrode is at least three times an axial length of the disc-shaped portion. Discharge device.

4. The discharge device according to claim 2, wherein the inner electrode further includes a cylindrical portion connected to a small-diameter end of the frustoconical portion provided in the inner electrode.

5. The distance between the axially intermediate portion of the outer peripheral surface of the inner electrode and the axially intermediate portion of the inner peripheral surface of the outer electrode in the discharge generation region is 5 mm to 25 mm. The discharge according to any one of claims 1 to 4, characterized in that:

6. The discharge device according to any one of claims 1 to 5, wherein an axial length of the discharge generation region is 2 mm to 10 mm.