JP2002061821A - Method and apparatus for combustion treatment of exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for combustion treatment of exhaust gas, in which a combustible substance is not retained, occurrence of gas-leakage accidents is seldom with a simple piping constitution. SOLUTION: Exhaust-gas treatment equipment 2 is provided with a burner part and a combustion chamber. A combustible gas is supplied to the burner part to form a burning flame from the burner to the combustion chamber. Exhaust gas G1 is conveyed to the combustion flame for oxidation decomposition. A H2/O2 generator 1 is provided to generate hydrogen (H2) and oxygen (O2) by electrolysis of water. The hydrogen (H2) and oxygen (O2) generated by the generator 1 are supplied to the burner as a combustion gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the exhaust gas produced by an industrial product processing processes such as semiconductor and liquid crystal, for example, silane gas (SiH _4), or a halogen-containing gas (NF _3, C
Combustion exhaust gas for combusting harmful combustible or hardly decomposable exhaust gas containing 1F ₃ , SF ₆ , CHF ₃ , C ₂ F ₆ , CF _4, etc., ie, by thermal decomposition and / or oxidative decomposition The present invention relates to a processing method and apparatus.

[0002]

2. Description of the Related Art A combustion type exhaust gas treatment apparatus as described above is
A burner section, a combustion chamber is provided on the downstream side of the burner section and the like, a combustible gas is supplied to the burner section, the combustible gas is burned to form a flame, and the flame is used to burn exhaust gas. I have. Combustible gases include hydrogen gas, city gas,
Propane gas or the like is used as a fuel gas, and oxygen or air is usually used as an oxidizing agent.

In the combustion type exhaust gas treatment apparatus as described above, since the fuel gas such as hydrogen gas, city gas, propane gas or the like is used as the combustible gas as described above, the fuel gas is used up to the combustion type exhaust gas treatment apparatus. Piping for supply must be laid. In addition, when city gas, propane gas, or the like is used as the fuel gas, there is a problem in that highly toxic carbon monoxide (CO) is generated during incomplete combustion.

[0004] Hydrogen gas is ignitable and explosive, but once it starts burning, the flame hardly blows out and extremely stable combustion is obtained, so that it is suitable as a fuel gas for combustion in a combustion type exhaust gas treatment apparatus. However, hydrogen gas has the disadvantage that the price is high and the running cost is high.
In addition, needless to say, under the storage container, the longer the pipe to be supplied to the exhaust gas treatment device, the more the pipe may leak at the pipe joint.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and does not require the storage of flammable substances.
It is an object of the present invention to provide an exhaust gas abatement system that does not require a complicated piping configuration and hardly causes a gas leakage accident. That is, a mixed gas of hydrogen gas and oxygen gas is used as a fuel gas for combustion, and equipment costs and running costs are used. It is an object of the present invention to provide a combustion type exhaust gas treatment method and apparatus which are inexpensive and can hardly leak hydrogen gas or oxygen gas.

[0006]

According to a first aspect of the present invention, an exhaust gas is introduced into a combustion flame.
In a combustion type exhaust gas treatment method in which a combustible component in the exhaust gas is thermally decomposed or oxidatively decomposed, a hydrogen gas and an oxygen gas are generated by electrolysis of water, and the hydrogen gas and the oxygen gas are used to form a combustion flame. It is characterized by being provided as.

According to a second aspect of the present invention, in the combustion type exhaust gas treatment method according to the first aspect, the hydrogen gas and the oxygen gas are subjected to the formation of a combustion flame as a mixed gas while maintaining the generated gas ratio. It is characterized by.

According to a third aspect of the present invention, there is provided a burner section for forming a combustion flame from hydrogen gas and oxygen gas, and an electrolyzer for water for generating the hydrogen gas and oxygen gas.

According to a fourth aspect of the present invention, there is provided the combustion type exhaust gas treatment apparatus according to the third aspect, further comprising:
The target exhaust gas is introduced into the combustion flame, and
A combustion chamber for oxidative decomposition is provided.

As described above, a so-called H ₂ / O ₂ generator having a water electrolyzer is provided, and hydrogen gas and oxygen gas are generated by the H ₂ / O ₂ generator by electrolysis of water. Since the mixed gas of the gas and the oxygen gas is supplied to the burner section, the supply of the oxidizing gas from the outside is unnecessary. If the H ₂ / O ₂ generator is arranged as close as possible to the burner section and a mixed gas with a production ratio of hydrogen and oxygen is supplied to the burner section, the piping can be shortened and the hydrogen gas and the oxygen gas are separated. Since there is no need to supply the water through the above line, the configuration of the piping is simplified, and the laying cost is reduced.

Of course, it does not prevent the two kinds of gases from being supplied to the burner section through separate lines and mixed and burned by a burner having a double nozzle structure. Further, since the piping is short, the possibility that hydrogen gas or oxygen gas leaks is reduced. In short piping, the likelihood of ignition is low, and it goes without saying that flashbacks from nozzles are structurally or operationally noted in practice. In addition, since water is electrolyzed and used as fuel on the spot, excess combustible gas is not retained, and H ₂ / O ₂ is used in an emergency.
By stopping the operation of the generator, it is possible to respond immediately, so that it is safe and the operating cost is low.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a system configuration of a combustion type exhaust gas treatment apparatus according to the present invention. 1 is an H ₂ / O ₂ generator that generates hydrogen gas and oxygen gas by electrolysis of water, and 2 is an exhaust gas treatment device that heats and oxidatively decomposes harmful and combustible exhaust gas G1 from a semiconductor manufacturing device. . A mixed gas of hydrogen and oxygen (H ₂ + (１ ／) O ₂ ) from the H ₂ / O ₂ generator 1 is supplied to a burner section (detailed later) of the exhaust gas treatment device 2 through a pipe 3. .

In the burner section, the mixed gas of hydrogen and oxygen burns to form a flame toward the combustion chamber. The exhaust gas G1 from the exhaust gas inflow pipe 4 is guided into the flame, and the exhaust gas which has been heated and oxidatively decomposed to remove the harm is discharged from the exhaust pipe 5.
As the H ₂ / O ₂ generator 1, an existing one can be used, and by disposing the H ₂ / O ₂ generator 1 near the burner portion, the length of the pipe 3 can be reduced. Further, if a mixed gas of hydrogen and oxygen is supplied, it is not necessary to supply hydrogen gas and oxygen gas through separate lines. Accidents can be eliminated and safety can be improved.

As shown in FIG. 2, the combustion type exhaust gas treatment apparatus is provided with an H ₂ / O ₂ generator 1 and a combustion chamber 20 provided with a burner section 10 close to each other.
00 can also be packaged. At this time, the case 1
It is desirable to provide an exhaust duct 101 at 00,
This makes it safer if a leak occurs in the pipe. Further, installation in a factory is easier than when hydrogen gas and oxygen gas are separated. The exhaust gas passing through the exhaust duct 101 is discharged to the atmosphere through a water scrubber in a factory.

FIGS. 3 and 4 show a specific example of the structure of the exhaust gas treatment apparatus 2. FIG. 3 is a longitudinal sectional view, and FIG.
It is A sectional drawing. The exhaust gas treatment apparatus is configured as a cylindrical hermetic container, and includes an upper burner section 10, a middle combustion chamber (combustion reaction section) 20, a lower cooling section 31, and a discharge section 32.
And As a cooling medium of the cooling unit 31, for example, a liquid such as water or a gas such as air is used.

The burner section 10 has a cylindrical body 12 forming a flame holding section 11 opening toward the combustion chamber, and an outer cylinder 13 surrounding the circumference of the cylindrical body 12 at a predetermined interval. An air chamber 14 for holding combustion air and a combustion gas chamber 15 are formed between the cylindrical body 12 and the outer cylinder 13. The air chamber 14 is connected to an air source (not shown), and the combustion gas chamber 15 is connected to the H ₂ / O ₂ generator 1 via the pipe 3.

An exhaust gas inlet pipe 16 (exhaust gas of FIG. 1) for introducing harmful exhaust gas G1 discharged from a semiconductor manufacturing apparatus, a liquid crystal panel manufacturing apparatus or the like is provided at the top of the cylindrical body 12 covering the upper side of the flame holding section 11. (Corresponding to the inflow pipe 4). The exhaust gas G1 does not necessarily need to be a flammable gas, and whatever it is, the combustion flame may be adjusted and thermally decomposed by the flame holding unit 11. Further, the cylindrical body 12 is provided with an air nozzle 17 communicating the air chamber 14 with the flame holding section 11 and a plurality of combustion gas nozzles 18 communicating the combustion gas chamber 15 with the flame holding section 11.

In this embodiment, as shown in FIG. 3, the air nozzle 17 extends at a predetermined angle with respect to the tangential direction of the cylindrical body 12 and blows out to form a swirling flow in the flame holding portion 11. It has become. Similarly, the combustion gas nozzle 18 extends at a predetermined angle with respect to the tangential direction of the cylindrical body 12, and blows out the combustion gas so as to form a swirling flow in the flame holding part 11. . The air nozzle 17 and the combustion gas nozzle 18 are evenly arranged in the circumferential direction of the cylindrical body 12.

The combustion chamber 20 is a space in which the secondary air is supplied downstream of the burner section 10 to oxidize and decompose exhaust gas. Cylindrical inner wall 2 arranged to be continuous with 11
It is divided by five. The inner wall 25 is made of, for example, fiber reinforced ceramic. Further, a heat insulating material 27 made of porous ceramic is inserted into a space 26 between the inner wall 25 and the outer container 24. In this outer container 24,
A purge air introduction pipe 28 for introducing purge air into the space 26 is connected.

The combustion chamber 20 has a U for detecting a flame.
A V sensor 29 and a pilot burner 30 for igniting the burner unit 10 are provided. In the lower part of the combustion chamber 20,
A plurality of nozzles 33 are provided on the lower edge of the cooling unit 31 at equal intervals in the circumferential direction, and water is sprayed from the nozzles 33 toward the center to form a water curtain, thereby cooling exhaust gas and exhaust gas. It is a scrubber device that captures particles inside. An exhaust pipe 34 for discharging treated exhaust gas is provided on a side wall of the discharge part 32, and a drain port 35 for discharging water injected from the nozzle 33 is provided on a bottom part.

In the exhaust gas treatment apparatus having the above structure, the combustion gas in the combustion gas chamber 15 is swirled toward the flame holding section 11 through the combustion gas nozzle 18. When ignited by the pilot burner 30, a swirling combustion flame is formed in the cylindrical body (cylinder) 12. On the other hand, the exhaust gas G1 to be treated is ejected toward the flame holding section 11 from an exhaust gas inflow pipe 16 which is opened on the inner wall surface at the top of the cylindrical body 12.
The discharged exhaust gas G1 is a combustion gas (including air).
The fuel is mixed with the swirling flow and burned, and further heated and oxidized and decomposed through the combustion chamber 20 to be harmlessly treated.

The gas treatment apparatus of the combustion type exhaust gas treatment apparatus according to the present invention is not limited to the structure shown in FIGS. 2 and 3, but it is essentially a burner section and a combustion chamber downstream of the burner section. And the combustion gas is supplied to the burner portion, the combustion gas is burned to form a flame, and the flame is used to burn the exhaust gas.
That is, the present invention provides, as a combustion gas to be supplied to the burner section,
There is a point in using a mixed gas of hydrogen and oxygen from a commercially available H ₂ / O ₂ generator that generates hydrogen gas and oxygen gas by electrolysis of water, and the configuration of the gas treatment device is not particularly limited. Absent. Of course, the number and arrangement of the nozzles for the burner, air supply, and the like are not limited, and the presence or absence of the combustion chamber 20 or less is optional.

[0023]

Effect of the Invention] According to the invention described in the claims as described, instead of the fuel gas tank, having an electrolyzer is provided with so-called H ₂ / O ₂ generator, the H ₂ /
Hydrogen gas and oxygen gas are generated by electrolysis of water in an O ₂ generator, and the generated hydrogen gas and oxygen gas are supplied to the burner section. Therefore, safe operation can be performed with a simple piping configuration. Further, if the H ₂ / O ₂ generator is arranged near the burner section, the piping for supplying the mixed gas of hydrogen gas and oxygen gas to the burner section can be shortened. In particular, if supplied as a mixed gas, there is no need to supply hydrogen gas and oxygen gas through separate lines.

Further, with the above configuration, the possibility that hydrogen gas or oxygen gas leaks is reduced. Further, since fuel gas is generated by electrolyzing water, expensive hydrogen gas is not required, and the required amount can be supplied in accordance with the required harmful gas amount.

[Brief description of the drawings]

FIG. 1 is a diagram showing a system configuration example of a combustion type exhaust gas treatment apparatus according to the present invention.

FIG. 2 is a diagram showing a configuration example of an apparatus including a combustion type exhaust gas treatment apparatus according to the present invention.

FIG. 3 is a longitudinal sectional view showing a specific configuration example of an exhaust gas treatment device of the combustion type exhaust gas treatment device according to the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

[Explanation of symbols]

1 H ₂ / O ₂ generator 2 exhaust gas treating apparatus 3 pipe 4 exhaust gas inlet pipe 5 exhaust pipe 10 burner 11 flame stabilizing portion 12 cylinder 13 the outer cylinder 14 the air chamber 15 a combustion gas chamber 16 exhaust gas inlet pipe 17 the air nozzles 18 burning Gas nozzle for combustion 20 Combustion chamber 21 Secondary air chamber 22 Partition plate 23 Secondary air nozzle 24 Outer container 25 Inner wall 26 Space 27 Insulation material 28 Purge air introduction pipe 29 UV sensor 30 Pilot burner 31 Cooling section 32 Discharge section 33 Nozzle 34 Exhaust pipe 35 drain port 100 housing 101 exhaust duct

Continued on the front page (72) Inventor Masaru Nakaba 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside the Ebara Corporation (72) Inventor Kazutaka Okuda 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Inside the Ebara Corporation (72) Inventor Keiichi Ishikawa 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside the Ebara Corporation (72) Inventor Kazichi Miyazaki 11-1, Haneda Asahi-cho, Ota-ku, Tokyo Inside the Ebara Corporation (72) Inventor Rikiya Nakamura 11-1 Haneda Asahimachi, Ota-ku, Tokyo F-term in Ebara Corporation 3K078 AA05 BA05 CA02 CA07 CA09

Claims (4)

[Claims] 1. A combustion type exhaust gas treatment method for introducing exhaust gas into a combustion flame and thermally decomposing or oxidatively decomposing flammable components in the exhaust gas, wherein hydrogen gas and oxygen gas are generated by electrolysis of water. A combustion type exhaust gas treatment method, wherein a gas and an oxygen gas are supplied as a combustion gas forming the combustion flame. 2. The combustion type exhaust gas treatment method according to claim 1, wherein the hydrogen gas and the oxygen gas are subjected to combustion flame formation as a mixed gas while maintaining a generated gas ratio. Exhaust gas treatment method. 3. A combustion type exhaust gas treatment device comprising: a burner section for forming a combustion flame from hydrogen gas and oxygen gas; and an electrolysis device for water for producing the hydrogen gas and oxygen gas. 4. The combustion type exhaust gas treatment device according to claim 3, wherein a combustion chamber for introducing a target exhaust gas into the combustion flame and performing heating and oxidative decomposition of the exhaust gas is provided downstream of the burner section. A combustion type exhaust gas treatment device characterized by the above-mentioned.