JP2002052309A - Discharge gas treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge gas treating device that enhances space utilization efficiency by effectively utilizing a duct which introduces gas from a generation source to the release part to reduce a space needed for the device installation. SOLUTION: The discharge gas treatment device is provide with a linear discharge electrode 16 along a duct 6 in at least partial space of the metal duct 6 introducing gas 2 from its generation source 4 to an atmosphere release part 8 to form a discharge treatment part 20 which generates non-equilibrium plasma discharge in the gas 2 between this discharge electrode 16 and the duct 6. Further, the device is provided with a pulse power source 12 generating the aforementioned non-equilibrium plasma discharge by applying a pulse voltage Vp between the discharge electrode 16 and the duct 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is, for example, a gas such as the exhaust gas of the plant, was treated by non-equilibrium plasma discharge, for example, contained in the gas NO _X, SO _X,
Regarding a discharge gas treatment device that removes or deodorizes harmful substances such as hydrogen sulfide and ammonia, and offensive odors, etc., more specifically, by effectively utilizing a duct that leads the gas from its source to an open to the atmosphere In addition, the present invention relates to means for reducing the space required for installing the apparatus and improving the space use efficiency.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional example of this type of discharge gas processing apparatus. In a factory or the like, when discharging the gas 2 such as exhaust gas from the generation source 4 and discharging it to the open-to-atmosphere section 8, conventionally, the discharge processing section 10 is usually placed in an appropriate place away from the generation source 4. Install, gas 2 emitted from the source 4
The duct 6 made of metal or resin leads to the discharge processing unit 10.

The discharge processing unit 10 is disclosed, for example, in Japanese Patent No. 2649.
No. 340, which is provided with several linear corona electrodes in a box-shaped casing. By this between the corona electrode and the casing to generate a pulse corona discharge by applying a pulse voltage V _P from the pulse power supply 12 in the gas 2 between them, harmful substances and malodorous substances contained in the gas 2 Removal and deodorization can be performed.

[0004] The gas 2 after the discharge treatment is discharged into the atmosphere from an atmosphere opening portion 8 provided at a place suitable for discharge. The open-to-atmosphere section 8 is, for example, an exhaust port or a chimney.

[0005]

When the length of the duct 6 is short, it may be about several meters, and when it is long, it may be about several tens of meters. The above duct 6
Requires a cross-sectional area corresponding to the flow rate of the gas 2 to be transported. Conventionally, such a duct 6 has been laid and connected from the generation source 4 to the discharge processing unit 10 using a support leg or the like.

As described above, in the conventional discharge gas processing apparatus,
Since the installation space for both the duct 6 for introducing the gas 2 and the discharge processing unit 10 is required, a large installation space is required, and there is a problem that the space utilization efficiency is poor. For this reason, for example, in places where the installation space is limited, such as in narrow lands or indoors, it has conventionally been difficult to install the discharge gas treatment apparatus.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to reduce the space required for installation of a device and to improve the space utilization efficiency by effectively utilizing a duct for guiding a gas from a gas generation source to an open air portion. .

[0008]

According to one aspect of the present invention, there is provided a discharge gas processing apparatus comprising: a space in at least a part of a metal duct for guiding a gas from a source to an open air portion;
A linear discharge electrode is arranged along the duct to form a discharge processing unit that generates a non-equilibrium plasma discharge in a gas between the discharge electrode and the duct, and a discharge processing unit is provided between the discharge electrode and the duct. And a pulse power source for applying a pulse voltage to generate a non-equilibrium plasma discharge.

A non-equilibrium plasma discharge is a discharge that generates a non-equilibrium plasma in which the gas temperature and the electron temperature are not in equilibrium (more specifically, the electron temperature is high but the ion temperature is low and the gas temperature does not rise). This discharge mode includes pulse corona discharge, creeping corona discharge, silent corona discharge, and the like.

[0010] The duct may be formed by spirally embedding a metal wire in a cylindrical insulator. In this case, a pulse voltage is applied between the metal wire and the discharge electrode from a pulse power source.

The duct may be made of an insulating material. In this case, an inner conductor is arranged on the inner wall of the duct, and a pulse voltage is applied between the inner conductor and the discharge electrode from a pulse power source.

In any of the above cases, at least a portion of the duct constitutes a discharge processing section. In the discharge processing part,
By generating a non-equilibrium plasma discharge in a gas, radicals and active species are generated in the gas. The radicals and active species decompose and modify the substances to be treated, such as harmful substances and malodorous substances, contained in the gas, and remove and deodorize the substances to be treated. .

As described above, according to the present invention, at least a part of the duct that guides the gas from the generation source to the open-to-atmosphere portion constitutes a discharge processing part. In other words, at least a part of the duct has a gas transport function. Since the gas processing function is also provided, the space required for installation of the apparatus can be reduced and the space utilization efficiency is improved as compared with a case where a duct and a discharge processing unit are separately provided as in the conventional example.

[0014]

FIG. 1 is a schematic diagram showing one example of a discharge gas processing apparatus according to the present invention. Parts that are the same as or correspond to those in the conventional example shown in FIG. 8 are denoted by the same reference numerals, and differences from the conventional example will be mainly described below.

The discharge gas processing apparatus is the same as the gas 2 described above.
This is an example in which the duct 6 that guides the air from the source 4 to the open-to-atmosphere section 8 is made of metal.

That is, in this example, a linear (including a rod-shaped) discharge electrode 16 is coaxially formed along the duct 6 at the center of the space in at least a part of the metal-made cylindrical duct 6. In the gas 2 flowing between the discharge electrode 16 and the duct 6, a discharge processing unit 20 for generating a pulse corona discharge, which is a form of non-equilibrium plasma discharge, is formed. This discharge processing unit 20 has a coaxial structure,
The outer cylindrical duct 6 becomes a non-corona electrode, and the inner linear discharge electrode 16 becomes a corona electrode.

The discharge electrode 16 may be provided within a part of the length of the duct 6 in the normal direction.
May be provided within the entire length of the. That is, the length L of the discharge electrode 16
In other words, in other words, the length L forming the discharge processing unit 20 may be determined according to the required discharge processing capacity. The same applies to other examples described later.

The discharge electrode 16 is supported in the duct 6 so as to be electrically insulated. Although a known insulator may be used as the supporting means, it will be described later (see FIGS. 2 and 3).
See) It is preferable to use a spiral insulator 22. The reason will be described later. The same applies to other examples.

The duct 6 may have a circular cross section (that is, a cylindrical shape) as shown in FIG. 3 or the like, may have a rectangular cross section (that is, a rectangular cylindrical shape), or may have another cross sectional shape. It may be something. The same applies to other examples described later.

Further, the discharge gas processing apparatus is provided with a high voltage (for example, the discharge electrode 1) between the discharge electrode 16 and the duct 6.
Average electric field strength in the space between the duct 6 and the duct 6 is 8 to 30 kV
/ Is about cm Such high voltage) and a short pulse (eg pulse width is applied by repeating the pulse voltage V _P of about 10Ns～1myuesu) and a pulse power supply 12 for generating the pulse corona discharge.

The application of the pulse voltage V _P to the discharge electrode 16 in the duct 6 is carried out, for example, via a current introduction terminal 18. The duct 6 is preferably grounded as in this example from the viewpoint of safety and the like. In that case, the duct 6 can be called a ground electrode.

The discharge processing unit 20 generates a pulse corona discharge in the gas 2 flowing therethrough,
A large amount of radicals and active species are generated in the gas 2. This radical and active species are carried out hazardous substances and malodorous substances contained in the gas 2 (e.g. NO _X, SO _X, hydrogen sulfide, ammonia, etc.) decomposition or modification etc., Ya the hazardous substances Processing such as removal of odorous substances and deodorization is performed.

As described above, in this discharge gas processing apparatus, at least a part of the duct 6 for guiding the gas 2 from the generation source 4 to the atmosphere opening part 8 constitutes the discharge processing part 20. In other words, at least a part of the duct 6 has both the function of transporting the gas 2 and the function of discharging. Duct 6
Can also be said to serve as the discharge processing unit 20 at least in part. Therefore, since a dedicated installation space for the discharge processing unit 20 is not required, the space required for installation of the apparatus can be reduced as compared with the case where the duct 6 and the discharge processing unit 10 are separately provided as in the conventional example. Efficiency is improved.

Therefore, for example, it is possible to install and use this discharge gas processing apparatus even in a place where the installation space is limited, such as in a narrow place or indoors. More specifically, there is an odor generation source indoors, and in the case where air near the odor source is discharged outside through a duct, by configuring the discharge processing unit 20 as described above using the duct, Processing such as deodorization and air purification can be performed without taking extra space even in a place where the space for installing the apparatus is very limited.

In this example, since the duct 6 is used as it is as one electrode (ie, a non-corona electrode) of the electric discharge processing section 20, it is not necessary to newly provide a non-corona electrode. Can be simplified. The same applies to the example of FIG.

The duct 6 may be hard and has no flexibility, or may be formed of a thin plate or a bellows-like thin plate and bendable (flexible; the same applies hereinafter).

The surface of the duct 6 is, for example, F
Those covered with an insulator such as RP (glass fiber reinforced plastic) or ceramics may be used.

Next, another embodiment will be described mainly on differences from the above embodiment.

FIGS. 2 and 3 show an example in which the duct 6 is formed by helically embedding a metal wire 62 in a cylindrical insulator 61. The metal wire 62 is originally embedded for improving the mechanical strength of the duct 6 and the like. The insulator 61 is made of, for example, a resin such as vinyl chloride. Such a duct 6 is bendable.

In the space inside at least a part of such a duct 6, the discharge processing section 20 is formed by arranging the linear discharge electrodes 16 in the same manner as in the above example. The metal wire 62 is preferably grounded for the same reason as in the above example. In that case, the metal wire 62 can be called a ground electrode.

The pulse voltage V _P from the pulse power supply 12
Is applied between the discharge electrode 16 and the metal wire 62, and a pulse corona discharge occurs in the gas 2 between the two.
The effect of processing the gas 2 thereby is the same as in the above example.

As a means for electrically insulating and supporting the discharge electrode 16 in the duct 6, a known insulator may be used as described above. However, as in this example, the spiral insulator 22 is used. It is preferable to use The main reasons are as follows.

(1) With known insulators, it is not easy to increase the creeping distance in order to prevent creeping discharge.
To increase the creepage distance, the insulator becomes large, and the pressure loss with respect to the gas 2 becomes very large. On the other hand, in the spiral insulator 22, as shown in FIG. 3, the creeping portion 22a of the surface is also formed in a spiral shape, so that the creeping distance between the discharge electrode 16 and the duct 6 can be easily increased. be able to. Therefore, creeping discharge on the surface of the insulator 22 can be easily prevented.

(2) As compared with the known columnar insulator, the spiral insulator 22 can easily reduce the cross-sectional area of the gas 2 in the flow direction, so that the pressure loss to the gas 2 is reduced. be able to. As a result, the capacity of the blower required to transport the gas 2 can be reduced.

(3) When the duct 6 is bent, the known insulator is too hard to cope with the bending, and the discharge electrode 16 cannot be maintained at a predetermined position (for example, the center) in the duct 6. . On the other hand, since the spiral insulator 22 is appropriately bent in accordance with the bending of the duct 6, the discharge electrode 16 can be maintained at a predetermined position (for example, the center) in the duct 6. This effect is particularly exhibited when the duct 6 is bendable.

The interval between the insulators 22 and the length of the insulators 22 in the direction along the axis of the duct 6 (the left-right direction in FIG. 2) depend on the mechanical strength required for supporting the discharge electrodes 16. It may be determined appropriately from the viewpoint of.

FIG. 4 shows an example in which the duct 6 is made of an insulating material such as a resin. Such a duct 6 is normally bendable. A planar inner conductor 24 facing the discharge electrode 16 is disposed on the entire circumference of the inner wall of the duct 6 and is used as one electrode (non-corona electrode). The inner conductor 24 is also preferably grounded (that is, made into a ground electrode) for the same reason as described above.

The inner conductor 24 is made of, for example, a thin metal plate,
Metal foil, metal mesh, and the like.

The length of the area in which the inner conductor 24 is arranged in the direction along the axis of the duct 6 (the front-back direction in FIG. 4) may be, for example, approximately equal to the length of the discharge electrode 16.

The pulse voltage V _P from the pulse power supply 12
Is applied between the discharge electrode 16 and the inner conductor 24, and a pulse corona discharge occurs in the gas 2 between the two 16 and 24. The effect of processing the gas 2 thereby is the same as in the above example.

As shown in FIG. 5, a connecting conductor 28 of a tubular shape (also referred to as a pipe shape) allowing the expansion and contraction of each discharge electrode 16 as shown by an arrow B is provided at the connection portion between the discharge electrodes 16. May be used. By doing so, even if the distance between the discharge electrodes 16 fluctuates due to expansion and contraction or bending of the duct 6, it can be absorbed by the connection conductor 28, thereby preventing the discharge electrode 16 from being deformed. And electrical connection between the discharge electrodes 16 can be ensured.

When the inner diameter of the duct 6 is large,
If the distance (inter-electrode distance) between the (or the metal wire 62 constituting the same or the inner conductor 24 provided on the inner surface) and the central discharge electrode 16 is not suitable for pulse discharge, for example, As in the example shown in FIG. 6, a structure in which a cylindrical ground electrode 26 is provided at the center of the duct 6 and a plurality of the above-described discharge electrodes 16 are arranged between the ground electrode 26 and the duct 6. . The duct 6 in this case is not limited to the one having the structure shown in FIG. 6, but may be any of the above-described examples.

The discharge processing section 20 in each of the above examples may be provided anywhere in the entire length of the duct 6, and the place where the discharge processing section 20 is provided is not limited. For example, it is also possible to provide at the bent portion of the duct 6. Therefore, the degree of freedom of arrangement is very large.

Further, on the downstream side of the discharge processing section 20 in each of the above examples, as shown in FIG. 7, for example, a catalyst function and an adsorption function for a substance contained in the gas 2 from the discharge processing section 20 are provided. You may provide the catalyst part 30 which has at least one. It is preferable that the catalyst unit 30 is disposed close to the discharge processing unit 20, so that the combined effect described below can be further enhanced.

In the example shown in FIG. 7, a material 32 containing at least one of a catalyst and an adsorbent is provided (filled) in the duct 6 immediately downstream of the discharge processing unit 20, and
Is composed. The material 32 is, for example, a metal oxide-based catalyst, activated carbon, zeolite, an activated carbon impregnated with or carrying a catalyst (eg, an alkali impregnated activated carbon, an acid impregnated activated carbon, a halogen impregnated activated carbon, etc.), or a zeolite carrying a catalyst. , Or a combination of one or more of the following.

If the catalyst section 30 as described above is further provided,
That is, if the discharge treatment unit 20 and the catalyst unit 30 are used in combination, the catalyst unit 30 can decompose and adsorb harmful substances and malodorous substances remaining in the gas 2 without being completely decomposed by the discharge treatment unit 20. Therefore, it is possible to more completely remove substances to be treated such as harmful substances and odorous substances from the gas 2.

The discharge processing unit 20 combined with the above-described catalyst unit 30 is not limited to the example shown in FIG. 7, but may be any one of the above-described discharge processing units 20.

[0048]

Since the present invention is configured as described above, it has the following effects.

According to the first to fourth aspects of the present invention, at least a part of the duct for guiding the gas from the generation source to the open-to-atmosphere portion constitutes a discharge processing section for processing the gas by non-equilibrium plasma discharge. As compared with the case where the duct and the discharge processing unit are separately provided as in the conventional example, the space required for installation of the apparatus is reduced, and the space utilization efficiency is improved. Therefore, for example, it is possible to install and use this discharge gas processing apparatus even in a place where the installation space is limited, such as in a narrow place or indoors.

According to the fifth aspect of the present invention, (1) the creepage distance between the discharge electrode and the duct can be easily increased, (2) the pressure loss with respect to the gas can be reduced, (3) Even when the duct is bent, a further effect is provided that the discharge electrode in the duct can be maintained at a predetermined position.

According to the sixth aspect of the present invention, it is possible to decompose or adsorb harmful substances and malodorous substances remaining in the gas without being completely decomposed in the discharge treatment part, and to perform the decomposition and adsorption in the gas part. There is an additional effect that it is possible to more completely remove substances to be treated such as harmful substances and malodorous substances.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a discharge gas processing apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating another example of a discharge processing unit.

FIG. 3 is an enlarged sectional view taken along line AA of FIG. 2;

FIG. 4 is a cross-sectional view illustrating another example of a discharge processing unit.

FIG. 5 is a cross-sectional view illustrating an example of a connection portion of a discharge electrode.

FIG. 6 is a cross-sectional view illustrating still another example of the discharge processing unit.

FIG. 7 is a schematic view showing another example of the discharge gas processing apparatus according to the present invention.

FIG. 8 is a schematic view showing an example of a conventional discharge gas processing device.

[Explanation of symbols]

 2 Gas 4 Source 6 Duct 8 Open to atmosphere 12 Pulse power supply 16 Discharge electrode 20 Discharge processing part 22 Insulator 24 Inner surface conductor 30 Catalyst part 61 Insulator 62 Metal wire

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takuya Kuwabara 47 Nisshin Electric Co., Ltd. Incorporated (72) Inventor Shigeru Kato 47-Umezu Takaunecho, Ukyo-ku, Kyoto-shi, Nisshin Electric F-term (reference) 4G075 AA03 AA37 BA05 CA18 CA47 DA01 EB21 FC15

Claims (6)

[Claims] 1. A linear discharge electrode is arranged along a duct in a space inside at least a part of a metal duct for guiding a gas from a generation source to an open-to-atmosphere portion. Forming a discharge processing section for generating a non-equilibrium plasma discharge in the gas, and a pulse power supply for applying a pulse voltage between the discharge electrode and the duct to generate the non-equilibrium plasma discharge. A discharge gas treatment device characterized by the above-mentioned. 2. A duct for guiding gas from a source to an open-to-atmosphere portion, wherein the duct is formed along a duct in at least a part of a duct in which a metal wire is spirally embedded in a cylindrical insulator. A linear discharge electrode is arranged to form a discharge processing unit for generating a non-equilibrium plasma discharge in a gas between the discharge electrode and the metal wire, and a pulse voltage is applied between the discharge electrode and the metal wire. And a pulse power supply for generating the non-equilibrium plasma discharge by applying a voltage. 3. A linear discharge electrode is disposed along at least a portion of a duct made of an insulator for guiding a gas from a source to an open-to-atmosphere portion along the duct, and the discharge electrode is provided on an inner wall of the duct. A planar inner conductor facing the discharge electrode is arranged to form a discharge processing unit for generating a non-equilibrium plasma discharge in a gas between the discharge electrode and the inner conductor, and the discharge electrode and the inner conductor A discharge gas processing apparatus comprising a pulse power supply for generating a non-equilibrium plasma discharge by applying a pulse voltage therebetween. 4. The discharge gas processing apparatus according to claim 1, wherein the duct is a bendable duct. 5. The discharge gas processing apparatus according to claim 1, wherein a spiral insulator is used to support the discharge electrode in the duct. 6. A catalyst unit having at least one of a catalyst function and an adsorption function for a substance contained in gas from the discharge processing unit is further provided downstream of the discharge processing unit. The discharge gas processing apparatus according to 2, 3, 4 or 5.