CN1227054C - Harm removal method and device for perfluorocarbons or perfluorinated compounds - Google Patents

Abstract

A method for decomposing and removing PFC components at a high destruction rate at a temperature as low as possible (low heat energy consumption) is provided. A method for detoxifying perfluorocarbons or perfluorocompounds, characterized by mixing one or more of a hydrocarbon gas and an ammonia gas with a gas to be treated containing perfluorocarbons or perfluorocompounds discharged from a production facility, and then thermally decomposing the mixed gas in a non-oxidizing atmosphere.

Description

Harm removal method and device for perfluorocarbons or perfluorinated compounds

The present invention relates to a detoxification method and a detoxification device for exhaust gas produced during the manufacturing of semiconductors, liquid crystals and other electronic circuit components, especially during cleaning and corrosion processes, and also relates to a detoxification method and a detoxification device for harmful gases produced during aluminum refining.

Hereinafter, when the field of the present invention is limited to the manufacture of electronic circuit components, the detoxification of gases used in the cleaning and etching processes will be described.

In semiconductor manufacturing equipment such as CVD (Chemical Vapor Deposition), deposition gases (such as SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , TEOS, PH ₃ , B ₂ H ₆ , NH ₃ , N ₂ O, etc.), after the deposition process is terminated, the inside of the semiconductor manufacturing device is usually cleaned with a cleaning gas (such as NF ₃ , C ₂ F ₆ , CF ₄ , SF _{6 ,} etc.).

These gases themselves have various dangerous properties such as flammability, explosion, corrosion, toxicity, etc. Therefore, before being discharged into the atmosphere, it is necessary to use a detoxification mechanism with means such as oxidative heating to eliminate harm (harmless treatment).

For the gases used in CVD semiconductor manufacturing equipment, new decomposition products (such as F ₂ , HF, SiO _x, etc.) are generated due to complex decomposition reactions, and these gases are discharged together with undecomposed deposition gases and cleaning gases .

As an example of the above, the operation of semiconductor manufacturing equipment such as CVD in semiconductor manufacturing generally proceeds as follows:

Use deposition gas such as SiH ₄ (which is poisonous to human body and explosive gas) for deposition → → use nitrogen to remove residual SiH ₄ gas in the CVD chamber → → use C ₂ F ₆ (has a greenhouse effect, but is not harmful ) and other cleaning gases to clean the CVD chamber → → use nitrogen as the CVD chamber cleaning gas to clean → → repeat the following operations.

PFC is included in the gas used in the above-mentioned CVD cleaning. It is the abbreviation of perfluorocarbon ( P er fluoro carbon ), and its representative compounds include tetrafluoromethane, trifluoromethane and hexafluoroethane. If the above carbon ( carbon ) is changed to compound ( compound ), then PFC also means NF ₃ , SF ₆ , SF ₄ and other carbon-free perfluorinated compounds.

Although the present invention is established for the purpose of removing the former PFC (perfluorocarbon) which has not been done technically so far as a kind of detoxification device and detoxification method, it can of course also be applicable to all PFCs including the latter. (Perfluorinated compounds) detoxification.

PFCs represented by CF ₄ and C ₂ F ₆ are nonflammable substances, and the toxicity of the gas itself to the human body is not yet known, at least not known to have acute or subacute toxicity. However, since the compound itself is stable, it can remain unchanged for a long time after being discharged into the atmosphere. The lifetime consumed in the atmosphere is 50,000 years for tetrafluoromethane, and 10,000 years for hexafluoroethane, while the earth's greenhouse effect coefficient (taking carbon dioxide as 1) tetrafluoromethane is 4400, and hexafluoroethane is 6200 (20 Years), there is a problem that it cannot be placed in the Earth environment. Therefore, people hope to establish a kind of detoxification means that can eliminate the harm of PFC represented by tetrafluoromethane and hexafluoroethane.

However, the former PFC, that is, compounds represented by tetrafluoromethane, trifluoromethane and hexafluoroethane, is not easy to decompose due to the stable C-F bond (bond energy as large as 130 kcal/mol), and it is extremely difficult to oxidize it simply by heating. break down.

For example, for hexafluoroethane, in order to decompose by cutting off the C-C chain, it is possible to limit the processing air volume to below 250 liters/min at a processing temperature of 1000°C, but for tetrafluoromethane, it is necessary to cut off the bond energy. The largest C-F bond requires 1400°C even at the above-mentioned air volume, and even so it is difficult to remove more than 80% of the harmful substances.

In addition, to reach a high temperature above 1400°C, the electric heater is also limited by the material of the heating element, and it is almost impossible to use it for a long time. Moreover, it is difficult to keep the whole device warm, and even if a heat insulating material is used in combination, the overall volume is too large to make a small device. More importantly, the heat consumption is too high.

In addition, the following new proposal has been disclosed in the art, that is, the "decomposition method of gaseous halocarbons" disclosed in the International Publication No. WO94/05399: Although it is reported that, for example, when tetrafluoromethane is used for detoxification, if oxygen is allowed to coexist, then It is possible at 600-700°C, but after verifying the content recorded in it in detail, it is impossible to eliminate the harm under this condition.

Although some people have tried to actively introduce hydrogen to thermally decompose PFC, but the processing temperature must be at a high temperature, and hydrogen is a flammable and explosive gas, so it has not been decided to use it from a safety point of view.

In view of this, it is required to provide a method and a pest removal device capable of decomposing and detoxifying PFC at a low temperature (heat energy consumption is low) as low as possible.

The detoxification method and detoxification device proposed by the present invention can eliminate PFC hazards at low temperature, the derived fluorine components can be eliminated by separate washing or fixing, and other components can basically be converted into carbon dioxide and water and discharged into the atmosphere. The specific method is as follows:

In the processed gas containing perfluorocarbons or perfluorinated compounds discharged from the manufacturing equipment, after mixing any one or two or more gases of hydrocarbon gas or ammonia gas, in a non-oxidizing atmosphere, at a temperature lower than the previous The above mixed gas is thermally decomposed at a temperature of 600-1300°C.

The above-mentioned "non-oxidizing atmosphere" will be described in detail later, but in a word, it refers to a state where oxygen does not exist around when the mixed gas is thermally decomposed.

Washing the above-mentioned treated gas with water in advance can not only remove the soluble components and dust contained in the treated gas discharged from the manufacturing equipment before the gas decomposition treatment, but also make the perfluorocarbon or Thermal hydrolysis of perfluorinated compounds.

When an excess amount of hydrocarbon gas is added, since there is unreacted hydrocarbon gas in the pyrolysis gas, carbon is generated in the above-mentioned thermal decomposition reaction, so it should be burned and removed in the following steps. The term "combustible components" refers to "residual hydrocarbon gas" and "carbon".

If the above description takes the thermal decomposition reaction of C ₃ H ₈ in a non-oxidizing atmosphere such as CF ₄ and C ₂ F ₆ as an example, it can be expressed as follows:

... (decomposed in gas decomposition tower or gas decomposition chamber)

... (decomposed in gas decomposition tower or gas decomposition chamber)

... (decomposed in gas decomposition tower or gas decomposition chamber)

...(combustion in combustion tower or combustion chamber)

6HF...removed by the second scrubber or absorption tower

Furthermore, the fluorine-containing compound produced by the above-mentioned thermal decomposition is removed by washing with water or chemical adsorption. The sequence of water washing or chemical adsorption step and combustible component combustion removal step can be followed.

The specific device consists of the following equipment:

(a) In the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the manufacturing equipment, one or two or more gases in hydrocarbon gas or ammonia gas are mixed, and the above-mentioned mixed gas is thermally decomposed in a non-oxidizing atmosphere The gas decomposition tower (2);

(b) a combustion tower (4) that combusts combustible components in the gas decomposed and treated in the gas decomposition tower (2);

(c) heater (16) that is arranged in gas decomposition tower (2) and combustion tower (4);

(d) supply the reducing atmosphere forming agent introduction pipe (6) of reducing atmosphere forming agent to the gas decomposition tower (2);

(e) an air inlet pipe (9) for supplying air to the combustion tower (4); and

(f) the second water scrubber (3) connected in series with the combustion tower (4) or the adsorption tower (3a) that is filled with granular calcium oxide or calcium carbonate.

Also can be on the upstream side of gas decomposition tower (2), be provided with the treated gas that contains perfluorocarbon or perfluorinated compound that manufacturing equipment is discharged, carry out the first water scrubber (1) that washes usefulness before gas decomposition .

The first water scrubber (1), gas decomposition tower (2), the second water scrubber (3) or gas decomposition combustion tower (11) (21) can also be set on the water tank (10), and these equipments also Can be set individually.

Above-mentioned combustion tower (4) and the second water scrubber (3) or adsorption tower (3a) all can be in the upstream side, as shown in Figure 1 (A), (B). Although adsorption tower (3a) is on the upstream side of combustion tower (4) in accompanying drawing 1 (C), combustion tower (4) also can be on the upstream side of adsorption tower (3a).

As shown in accompanying drawing 2 (A), (B) and (C) and accompanying drawing 3～5, gas decomposition chamber (12) (22) and combustion chamber (14) (24) can be separated by partition (13) (23 ) to separate the gas combustion decomposition tower (11) (21) into one. The details about the gas combustion decomposition tower (11) (21) will be introduced later.

The main unit operations of the above-mentioned invention are divided into the following three stages:

(a) Thermal decomposition of PFC

(b) Scrubbing exhaust or fixed removal of fluorine-containing compounds

(c) Combustion removal of other combustible components (residual hydrocarbon gas and carbon)

The most important constituent step of the present invention is the PFC thermal decomposition in above-mentioned (a), and it forms such a treatment method, promptly can make the detoxification rate "[ Import the PFC concentration contained in the gas in the detoxification device-(contained PFC concentration in the exhaust gas/introduce the PFC concentration in the gas in the detoxification device)×100]" reaches more than 90%.

The thermal decomposition of PFC as the core content of the present invention can use electric heater as heat source, or be the flame combustion of heat source such as liquid fuels such as liquefied petroleum gas (LPG), liquefied natural gas (LNG) or gaseous fuels such as methane, hydrogen, carbon monoxide means, and the position of the heat source for heating can be in the gas decomposition tower (2) (or gas decomposition chamber (12) (22). Below except accompanying drawing 2～5, all mention gas " decomposition tower: all comprise gas decomposition Chamber (12) (22)) outside or inside.

In the gas decomposition tower (2) space, PFC is the main component, and the treated gas mixed with carrier gas nitrogen is usually introduced. And at the same time feed lower saturated or unsaturated hydrocarbon gas (wherein so-called "lower" refers to C1～C8 components, particularly preferably C1～C4 components saturated hydrocarbons) or ammonia gas, or feed the mixed gas of these gases simultaneously.

In this case, one of the conditions is, for example, in the case of using _O2 or _O3 together in CVD, although the residual gas used flows into the decomposition tower in the form of exhaust, no other _O2 and _O3 or external air is artificially injected. , at least keep the gas decomposition tower from becoming oxidized. This state refers to, in non-oxidizing atmosphere, does not exist the state of free oxygen in gas decomposition tower (2) or gas decomposition chamber (12) (22).

In this state, although the decomposition of PFC is carried out under predetermined conditions such as the PFC concentration in the treated gas, the air volume of the treated gas, and the space temperature in the gas decomposition tower, it can be proved that the temperature and oxidative properties of the atmospheric gas at this time Compared with the treatment temperature in the gas system under the atmosphere, even if it is several hundred degrees lower, it can almost completely eliminate the harm.

It is considered that this is because the hydrocarbon gas or ammonia gas introduced in the form of a PFC decomposition treatment agent is thermally decomposed in a non-oxidizing atmosphere (for example, when propane is used, various decomposition products such as methane, ethane, ethylene, propylene, and hydrogen are generated. ), the active hydrogen in the free radical state is generated during the decomposition process to decompose the PFC, and the F component in the PFC is separated in the form of _F2 or HF.

In addition, PFC is alone or in oxidative atmosphere, also is difficult to obtain the result that makes detoxification rate reach more than 80% even at the high temperature close to use material temperature limit, this illustrates that the decomposition mechanism of compound in gas decomposition tower is completely with the present invention different.

According to the present invention, the treatment gas discharged from the gas decomposition tower becomes _F2 or HF, and the decomposition treatment agent becomes carbon black according to the remaining hydrocarbon decomposition gas and conditions. Therefore, the two component gases of fluorine-containing exhaust gas and combustible gas are both treated harmlessly.

That is to say, the former is absorbed and dissolved in water through the water scrubber, or is adsorbed and separated by calcium oxide or calcium carbonate solid adsorbent and then discharged out of the system. The latter burns it in the presence of external air, becomes the final gas and discharges it into the atmosphere.

The present invention is illustrated below with preferred embodiments.

In the detoxification device of the present invention, the thermal decomposition of (a) PFC, (b) generation of fluorine-containing compound cleaning exhaust or fixed detoxification, (c) the combustion of other flammable components to detoxify etc. implement the above three elements The various devices are combined and accommodated into one.

Accompanying drawing 1 is the synoptic diagram of the outline of detoxification device of the present invention. In accompanying drawing 1, (1) is the front water scrubber (the first water scrubber) that is arranged on gas decomposition tower (2) front end (upstream side). The gas to be treated containing PFC sent through the gas to be treated containing PFC introduction pipe (5) is initially passed through the front water scrubber for water washing.

The treated gas discharged from the front water scrubber (1) is sent into the gas decomposition tower (2) through the water tank (10). Use electric heater (16) to gas decomposition tower (2) heating, can adopt external heating or internal heating. In the present embodiment, the vertical electric heater (16) is vertically arranged in the gas decomposition tower (2) from the top plate. In either case, corrosive gases _F2 and HF are generated inside the gas decomposition tower (2), and metal materials are corroded by these substances, and high nickel content alloys such as インコネル (Inconel) (trademark) alloys must be used The gas decomposition tower (2) is manufactured, or the inner surface of the gas decomposition tower (2) is coated with a ceramic material mainly composed of aluminum oxide. When the electric heater (16) is located inside the gas decomposition tower (2), in order to protect the heater, the heating element should be inserted into the aluminum oxide ceramic protection tube.

After cleaning the chamber of semiconductor manufacturing equipment such as CVD with PFC gas, nitrogen gas is sent into the chamber, and the used PFC gas in the chamber is flushed with nitrogen gas. Because the above-mentioned flushing nitrogen becomes the carrier gas, although the gas after use of the PFC represented by CF ₄ and C ₂ F ₆ is introduced into the gas decomposition tower (2), the O ₂ and O used in CVD in this case ₃ and the like oxidant residual gas is also introduced into the detoxification device at the same time. However, it is not necessary to supplement oxygen or air and the like in the gas decomposition tower (2) compulsorily.

Through the reducing atmosphere forming agent introduction pipe (6), actively introduce low-level (C1～C8 components) saturated or unsaturated hydrocarbons or ammonia or its mixed gas into the gas decomposition tower (2) as the reducing atmosphere forming agent. The PFC gas is decomposed in a reducing atmosphere.

Said lower saturated or unsaturated hydrocarbons can use methane, ethane, propane, normal or iso (the same below) butane, pentane, hexane, heptane, octane, ethylene, propylene, butene, butane As dienes, aromatic hydrocarbons such as benzene, toluene, and xylene can also be used. In addition, city carbon gas is also available.

However, the ratio of C to H in hydrocarbons, the more C, the more carbon remains, and the easier it is to generate carbon, so methane, ethane, propane and butane are preferably used.

In addition, ammonia, like hydrocarbons, binds to a plurality of hydrogen atoms and functions as a hydrogen atom donor, so it can also be used as a reducing atmosphere forming agent. When ammonia is used, it neutralizes the HF generated in the gas decomposition tower to generate NH ₄ F salt, which is expected to have an effect of preventing corrosion of equipment materials.

As the reducing atmosphere forming agent, any one of the above-mentioned gases may be used alone, or two or more gases may be used in combination.

Within the broad range of PFC concentration that the present invention can remove, at least 90% or more of harmful substances within the range of 100ppm to 5% can be removed. And for less than 100ppm and more than 5% harmful substances, though also can eliminate the harmful, the harmful removing rate can not reach more than 90% sometimes.

In the present invention, the air volume of the processing gas is preferably in the range of 5 to 700 liters/minute. If the air volume is below 5 liters per minute, the energy efficiency of the device will be reduced and will not work. And under the situation of being greater than 700 liters/min, the effect of treating gas transfer energy is insufficient, and the detoxification rate tends to decrease.

The amount of gas of the reducing atmosphere forming agent that coexists when the PFC is decomposed is 0.1 to 3 moles for 1 mole of PFC. When used below 0.1 mole, the effect of reducing the decomposition temperature and improving the detoxification rate as the purpose of the present invention is not enough, and under the situation of more than 3 moles, although the detoxification rate can reach more than 90%, the carbon in the treatment exhaust The thermal decomposition products of hydrocarbons increase, the hydrocarbons are wasted, and the subsequent process of the treated gas becomes complicated, so it is not good.

The temperature in the gas decomposition tower (2), no matter the heat source is placed inside or outside the gas decomposition tower (2), compared with the situation without simple thermal decomposition (comprising oxidative decomposition), the inventive method can lower the temperature by hundreds of degrees. processed in the area.

In the case of simple thermal decomposition, such as the example of C ₂ F ₆ treatment, the detoxification rate is only 80-85% in the temperature range of 1100-1200°C, and the by-product CF ₄ is also produced in the treated gas. In addition, for CF ₄ , even in the 1400°C temperature region, the highest rate of detoxification is only 70%, which is far below the 90% of the purpose of the present invention. When using the electric heater (16) as the heat source, it is technically difficult to use it for a long time at about 1400°C, and it should only be used below 1100°C.

Compared with this, according to the present invention, the existing PFC can be used for detoxification at low temperature alone or under the coexistence of oxygen. For example, 850 ° C is enough for C ₂ F ₆ treatment, and for CF ₄ , it is 1000 ~ 1100 ° C It can be treated with a pest removal rate of more than 90%.

The hydrocarbon gas introduced into the decomposition tower, if oxygen or ozone is used as the gas for oxidizing PFC in the CVD cleaning process, the hydrocarbon gas reacts with the residual components of oxygen or ozone to consume it, and is further thermally decomposed at the processing temperature to become various ingredients.

For example, in the case of propane, it is thermally decomposed at 780°C to become methane, ethane, ethylene, propylene, hydrogen and carbon. In this process, substances such as C ₂ F ₆ and CF ₄ also participate in the decomposition process of PFC, and detach F components in the form of F ₂ or HF components.

The F component in the PFC treated in the gas decomposition tower is discharged in the form of _F2 and/or HF. This treated gas passes through the water scrubber (second scrubber) (3) at the rear to dissolve the F component in water, or introduce it into an adsorption tower with calcium oxide or calcium carbonate solid filling, and convert it to CaF _{The 2} form is removed by adsorption.

The gas that has removed the F component in any of the above-mentioned methods is sent in the treated gas combustion tower (4). Here, it is mixed with the external air sent through the air inlet pipe to burn combustible components to form carbon dioxide and water, which are then discharged into the atmosphere through the air exhaust pipe (8). (7) represents exhaust fan among the accompanying drawings.

It is also possible to reverse the positions of the treated gas combustion tower (4) and the rear water scrubber (3), so that the gas treated by the gas decomposition tower is combusted in the combustion tower (4) and scrubbed by the rear water The device (3) is cooled and discharged into the atmosphere. That is to say, as long as the treated gas combustion tower (4) and the rear water scrubber (3) are arranged in series, whichever is earlier is all right.

【Example 1】

Present embodiment is the example that is processed with the first water scrubber (1), gas decomposition tower (2), second scrubber (3) and combustion tower (4) successively.

Contain 1% CF ₄ and 99% N 30 liters of mixed gas _, pass in the gas decomposition tower (2) after the front water scrubber (1) (the first scrubber) washes. This gas decomposition tower (2) inner wall is covered with alumina castable refractory material, and its inside is provided with 15 rod-shaped electric heaters (16) (enclosed in the alumina protection tube), remains therein with hanging state.

Supply 90% propane and 10% n-butane mixed gas as reducing atmosphere forming agent in gas decomposition tower (2) with 0.3 liters/minute speed. The heater surface temperature was maintained at 1100°C. Utilize the suction effect of the fan (7) arranged outside the equipment to keep the inside of the system in a negative pressure state, and decompose the by-products during the gas decomposition process through the rear water scrubber (3) (second water scrubber) _F2 and HF absorb dissolved in water. The water consumption in this case was 10 liters/minute.

Then the gas cleaned by the second water scrubber (3) is passed into the combustion tower (4) kept at 500° C., and it is oxidized and burned under the coexistence of introducing air from the outside. The _{concentration} of CF in the treated gas was determined to be 50ppm, and _the CF detoxification rate was 99.5%.

[Comparative Example 1]

In the detoxification rate device identical with embodiment 1, with 30 liters/minute air flow supply with embodiment 1 identical CF ₄ Composed gas. Then the surface temperature of the heater is maintained at 1100° C., and no hydrocarbon gas used as a reducing atmosphere _forming agent is supplied at all. The concentration of CF in the treated gas is measured to be 9100 ppm, that is, the detoxification rate is only 9%.

Under the above-mentioned temperature condition, add and feed air with 5 liters/minute flow rate from the outside again, CF in _the gas after treatment Concentration is measured as 3000ppm, and CF _The detoxification rate is 70%.

The above results show that compared with the reference example, although the temperature of the present invention is 350° C. lower, it can almost completely remove the pests. Therefore, since the purpose of detoxification can be achieved at a temperature lower than 300-400°C, energy consumption can be reduced, and the range of material selection from the perspective of device heat resistance is also enlarged.

[Example 2]

Although the present embodiment is also an example of processing in the order of the first water scrubber (1), gas decomposition tower (2), the second scrubber (3) and combustion tower (4), compared with embodiment 1 , the PFC of the treated object and the reducing atmosphere forming agent used are different.

The mixed gas composed of 2% C ₂ F ₆ , 97.5% N ₂ and 0.1% oxygen is sent to the gas decomposition tower after passing through the front scrubber at a speed of 100 liters/minute.

This gas decomposition tower (2) is made by SUS316L, and its inner wall is covered with aluminum oxide castable refractory material, and the outer circumference of the tower is wound with heating wire (not shown), which belongs to the structure of heating from the outside. With 4 liters/minute speed, to this decomposition tower (2) interior supply is made up of city carbon gas (13A) of 88% methane, 6% ethane, 4% propane and 2% butane as reducing atmosphere forming agent. Make decomposition tower (2) interior space temperature keep on 850 ℃. After the treated gas is washed by the rear water scrubber (3) (water supply at a rate of 15 liters/minute), it is passed into the combustion tower (4) supplied with air from the outside and maintained at 600° C., and then discharged.

In addition, carbon powder (powdered carbon) is suspended in the rear water scrubber (3) under this condition, and the misty carbon is sent to the combustion tower (4) to remove.

The measured value of C ₂ F ₆ discharged into the atmosphere is 400ppm, and the detoxification rate is 98%, and no CF ₄ is found in the treated gas.

[Example 3]

Under the condition of above-mentioned embodiment 2, use the device that has the adsorption tower (3a) of the granular calcium oxide that fills soybean granularity to replace rear water scrubber (3), make the gas after gas decomposition tower (2) process pass through This adsorption tower (3a). Under the condition of external fan (7) suction, do not find any pickling liquid composition in the discharged gas.

[Comparative Example 2]

The PFC exhaust was treated under the same conditions as in Example 2, except that city carbon gas was not supplied. After gas detection in the atmosphere, the residual C ₂ F ₆ concentration is 1.76%. That is to say, the pest removal rate is 12%. In addition, CF ₄ is newly by-produced in the treatment gas. Therefore, the PFC pest removal rate is worse than the above-mentioned 12%.

The above conditions are the same except that the space temperature in the tower is kept at 1150°C, the concentration of C ₂ F ₆ in the exhaust gas after the detoxification of C ₂ F ₆ is 4000ppm, and the detoxification rate is 80%. In addition, it was found that the CF ₄ component was by-produced.

【Example 4】

Present embodiment is a kind of modified example of device of the present invention, and accompanying drawing 2 shows the general situation of device of the present invention, and among the figure (A) is a top sectional view, and figure (B) is a front sectional view.

In accompanying drawing 2, (11) is gas decomposition combustion tower, and the decomposition chamber (12) that plays gas decomposition tower effect and the combustion chamber (14) that plays combustion tower effect are adjacently connected as a whole by heat resistance partition (13) . That is to say, in the embodiment device of the present invention, gas decomposition combustion tower (11) can be regarded as the equipment that decomposition tower and combustion tower are connected as a whole with partition. (This is also the same in Example 5 below.)

The partition (13) is made of ceramic material, for example, a partition made of カオウ-ル can be used.

A ceramic lining heat insulating layer (15) is arranged around the gas decomposition combustion tower (11).

(16) is heater, hangs down from the top plate (11a) of gas decomposition combustion tower (11), is arranged in gas decomposition chamber (12) and combustion chamber (14). (17) is a reducing atmosphere forming agent introduction pipe, which links to each other with the piping (5a) connecting the front water scrubber (1) and the gas decomposition chamber (12), and the reducing atmosphere forming agent is mixed into the gas scrubber through the front water. In the processed gas after the device (1) is washed with water, the mixed gas is sent into the gas decomposition combustion tower (11).

(18) is an air introduction pipe, which is connected with the combustion chamber (14), and external air is sent into the combustion chamber (14).

The treated gas introduced into the gas decomposition chamber (12) through the front water scrubber (1) is decomposed under the reducing atmosphere in the gas decomposition chamber (12), and passes through the partition wall (13) while retaining heat energy. The upper gap flows into the adjacent combustion chamber (14), is burned in an oxidizing atmosphere, and then is discharged into the atmosphere after being cooled and washed by the water scrubber (3) arranged downstream of it.

The gas decomposition chamber (12) and the combustion chamber (14) are separated by a partition (13), and communicated through the communication port (11b) on the upper end of the partition (13), and the processed gas decomposes while rising in the gas decomposition chamber (12). The gas enters the combustion chamber (14) through the communication port (11b), where it flows toward the water tank (10), and combustible components therein are burned. Therefore, since there is no rear water scrubber (3) shown in accompanying drawing 1 between the two, there is no cooling problem, so energy consumption can be reduced.

If adopt the device of this structure, then compare with that kind of standard type device shown in accompanying drawing 1, promptly compare with the situation that gas decomposition tower (2) and combustion tower (4) are provided separately, can make device whole more Compact, reducing the footprint of the device setup.

In addition, since the water tank (10) does not have to be set directly below the gas decomposition tower (11), the water tank (10) can be arranged behind the gas decomposition combustion tower (11) in a horizontal position, so it can also save the energy from the upper high temperature part (i.e. Decompose the heat loss that the water in the radiant heat heating water tank (10) of combustion tower (11)) causes.

Not only that, the external air introduced into the combustion chamber (14) through the air introduction pipe (18), due to the process of moving downward in the combustion chamber (14), is absorbed by the thermal energy in the gas decomposition chamber (12) via the partition wall (13). heating, so the energy used can be further reduced.

Shown in the present embodiment and accompanying drawing 1 below, be provided with gas decomposition tower (2) and combustion tower (4) and the independent type that water scrubber is set between gas decomposition tower (2) and combustion tower (4) equipment, compare its pest removal rate and energy use.

First illustrate independent type equipment, feed 1.5% CF in decomposition tower (2) with 60 liters/minute speed ₄ and 98.5% N ₂ mixed gas, supply 90% propane and 10% normal therein with 0.6 liters/minute speed Butane mixed gas is used as a reducing atmosphere forming agent, and the heater is kept at 1300°C.

After the analysis of the gas discharged from the combustion tower (4), it contains CF ₄ 500ppm, and the detoxification rate is 96.7%. In addition, the power consumption under normal conditions is 7 kW/h.

Because this decomposing tower (2) internal volume is 24 liters, and the processing gas flow rate is 60.6 liters/minute=3636 liters/hour, so

SV (Space Velocity) = 3636/24 = 151.5/hour.

On the other hand, for the present embodiment device, under the above-mentioned same gas composition and heater temperature, after CF ₄ detoxification, the CF concentration in the treated gas is _400ppm , and the detoxification rate is 97.3%.

Under normal conditions, the power consumption is 3.5 kW/h, and the energy consumption is only about 1/2 of the stand-alone equipment.

Because the internal volume of gas decomposition chamber is 21 liters in the present embodiment, the flow rate of processing gas is 60.6 liters/minute=3636 liters/hour, so

SV=3636/21=173.1/hour.

That is to say, the device of this embodiment not only has a much larger SV, but also can obtain almost the same pest removal rate as the independent equipment, and the energy consumption can also be reduced to 1/2 in addition.

【Example 5】

This embodiment relates to a device that improves the PFC detoxification rate and further improves thermal energy efficiency at the temperature at which the electric heater (26) can be used.

In order to improve the detoxification rate of PFC gas, the equipment structure must be able to fully transfer energy to the gas to be processed and ensure its processing time.

Therefore, in order to ensure the transmission and shielding of heat while setting the electric heater (26) horizontally in this embodiment, and then have a sufficient stirring effect on the air flow, several electric heaters are horizontally arranged in the form of grates at the position below the electric heater. Heat Resistant Rod (29).

Accompanying drawing 3 has shown the outline of the device of this embodiment. (30) is the treated gas import pipe containing PFC, (20) is a water tank, (31) is a first water scrubber, (21) is a gas decomposition combustion tower, (32) is a second water scrubber, (33) is the gas exhaust pipe leading to atmosphere. The processed gas containing PFC discharged from the manufacturing equipment is sent into the first water scrubber (31) through the upper space of the water tank (20) through the PFC-containing processed gas introduction pipe (30). Certainly, also can directly import from the lower end of the first water scrubber (31).

Accompanying drawing 4 is the side sectional view of gas decomposition combustion tower (21), and accompanying drawing 5 is the horizontal section view of gas decomposition combustion tower (21). The gas decomposition combustion tower (21) is divided into the gas decomposition chamber (22) and the combustion chamber (24) that plays the combustion tower effect by the next door (23) that has heat resistance in the gas decomposition tower effect, in said next door ( 23) The upper end has a communication port (21b) communicating with the decomposition chamber (22) and the combustion chamber (24). Therefore, the gas decomposed under the reducing atmosphere in the gas decomposition chamber (22) can flow into the combustion chamber (23) from the communication port (21b) on the upper part of the partition wall (23).

Same as embodiment 4, between the decomposition chamber (22) and the combustion chamber (24), it is separated by a partition (23) and adjacent, and there is no second water scrubber (3) between the two, so the gas is decomposed After treatment, there will be no problem of being cooled by the second water scrubber (3) as shown in Figure 1, so energy consumption can be reduced.

The partition (23) is made of a ceramic material, for example, a partition made of カオウ-ル can be used. In order to reduce the thermal energy loss of the gas decomposition combustion tower (21), a lining heat insulating layer (25) is formed with a ceramic material. (27) is a reducing atmosphere forming agent introduction pipe, and (28) is an air introduction pipe.

(26) is an electric heating rod, which is arranged to run through the gas decomposition combustion tower (21) and its inner partition (23) with the horizontal direction. The reason why the electric heating rod (26) is arranged in the horizontal direction is because the temperature unevenness is easily produced when the upright (making it vertical) is set.

That is to say, because even if the heater top reaches the set temperature, the atmosphere gas in the gas decomposition chamber (22) is affected by the air flow and the upper part is hotter, so when the electric heater (26) is vertically arranged, below the heater center It is difficult for the lower layer to ensure sufficient temperature for decomposition. On the other hand, if the temperature of the lower layer is controlled higher than the set temperature, the upper part of the heater is easily in an overheated state, which not only reduces the energy efficiency, but also tends to cause problems such as fusing of the heating element (26a) in the electric heater (26) .

At this time, if the electric heater (26) is horizontally arranged, then the temperature can be kept evenly distributed along the length direction of the electric heater (26), and an atmosphere gas at a temperature required for thermal decomposition of the PFC gas can be reasonably formed.

In addition, when the pest removal rate device is arranged in the clean room, there is often not enough space between the top plate of the clean room and the pest removal device. When replacing a faulty heater, the electric heater (26) is erected in a vertical state Setting is not suitable for operation, but when the electric heater (26) is horizontally arranged like this embodiment, the electric heater (26) can be taken out along the horizontal direction, so it has the advantage of being extremely easy to operate.

The use number of electric heater (26) is advisable with 6～12, divides 2～4 row equidistant settings, each row horizontal setting position is staggered during setting, makes gas be difficult to directly enter. In this embodiment, considering the convenience of use, there are three rows of three rows, a total of nine rows. The electric heater (26) used wherein is to insert the heating element (26a) made of SiC into the protective tube (26b) made of 99.5% α-alumina with an outer diameter of φ40.

(29) is several heat-resistant rods that are arranged horizontally at 100 millimeters below the bottom row of electric heaters (26), and are set through the next door (23) along the horizontal direction. In this embodiment, although the electric heater (26) and the heat-resistant rod (29) are arranged in parallel (the longitudinal direction is arranged in the same direction), they can also be arranged in an orthogonal direction.

The heat-resistant rod (29) is preferably heat-resistant above 1300°C and has corrosion resistance to _F2 and HF. Ceramic rods can be used, but the cross-section is circular with _Al2O3 as the main component _. material is particularly suitable. Heat-resistant rod (29) can use solid (rod _{material) or hollow (pipe material), although used the 99.5% α-Al of φ 10 millimeter in this example O The pipe material of O 3 system} is made up of 5 sections and totally 48, but The pipe diameter and the number of pipes used are not limited thereto, and can be appropriately selected and determined. Its setting and the heater (26) should make the gas difficult to advance in a straight line equally, so that the positions of each section along the horizontal direction are staggered from each other.

The heat-resistant rod (29) has the same effect as the grate in the boiler structure, that is, it prevents it from being heated by the upper heater, causing heat energy to be transferred to the bottom of the gas decomposition combustion tower (21), and it can also treat the gas containing PFC and the gas generated by reduction. Preheat the reducing atmosphere forming agent fed into the reducing atmosphere forming agent introduction pipe.

In addition, the PFC-containing gas and reducing atmosphere forming agent flowing through the gaps of several heat-resistant rods (29) can be mixed by the generated turbulent flow under the action of the heat-resistant rods (29).

Since the heat-resistant rod (29) reduces the flow velocity, the residence time of the gas in the gas decomposition tower (21) can be fully guaranteed, and the detoxification rate can be improved.

In view of electric heater (26) being arranged on the gas decomposition combustion tower (21) and its internal partition (23) through, and heat-resistant rod (29) is also provided through through the partition (23), so should be coated with resistant Thermal and corrosion-resistant sealant based on ceramic fiber to prevent gas leakage.

The temperature of each part in the present embodiment device is as follows:

Heater surface: 1200～1350℃

Gas decomposition chamber space and combustion chamber space: 1200～1300℃

The lower part of the gas decomposition chamber (below the heater, above the heat-resistant rod): 800°C

The bottom part of the gas decomposition chamber (the part of the gas to be processed under the heat-resistant rod):

200～300℃

The lower part of the combustion chamber (below the heater, above the heat-resistant rod): 1200°C

The bottom part of the combustion chamber (the part where the gas is discharged under the heat-resistant rod): 800°C

Rear of the outlet of the second water scrubber: 200°C.

It can be seen from these results that the heat-resistant rod (29) can effectively prevent the effect of thermal energy from spreading downward.

And then carry out actual decontamination with present embodiment device.

At a flow rate of 140 L/min, the mixed gas of 1% CF ₄ and 99% N ₂ is introduced into the upper decomposition chamber ( 22 ) through the first scrubber ( 31 ).

With the flow velocity of 1.4 liters/minute, the propane used as reducing atmosphere forming agent is introduced in the gas decomposition chamber (22) by the reducing atmosphere forming agent introduction pipe (27) connected with the first scrubber (31) top , for thermal decomposition in the coexistence with _CF4 .

The gas (23) thermally decomposed in the gas decomposition chamber (22) moves into the combustion chamber (24) from the gap on the upper part of the partition wall (23), and together with the external air sent in from the air introduction pipe (28) in the combustion chamber (24) ) to burn to remove combustible components, and discharge into the atmosphere after being cooled and washed by the second water scrubber (32) below the combustion chamber (24).

After analyzing the gas discharged from the second water scrubber (32), _CF4 was 50ppm. That is to say, the pest removal rate of CF ₄ is 99.5%. In addition, the electricity used for the above pest control is 9 kilowatts per hour.

Except using ammonia as reducing atmosphere forming agent with 3.6 liters/minute flow rate, under the same conditions with above-mentioned harm removal. Results The CF ₄ in the treated gas was 60ppm, and the harm removal rate of CF ₄ was 99.4%.

[Comparative Example 3]

Except that 9 electric heaters are vertically arranged, and no heat-resistant rods are used at all, the same device as in Example 5 is used to remove harmful effects to CF ₄ .

The amount of treated gas is reduced to 120 liters/minute, and after using 1.2 liters/minute of propane at the same temperature, CF in the treated gas is _2500ppm , and the detoxification rate is 75%.

In addition, the power consumption at this time was 15 kW/h, which was 1.7 times that of the device in Example 5. It can also be illustrated that the pest removal device of embodiment 5 has a high rate of pest removal and low energy consumption.

Accompanying drawing 6 is except that with the embodiment shown in accompanying drawing 3, the example that electric heater (26) is arranged in parallel with respect to partition (23). Under the occasion of accompanying drawing 4, in order to make the exhaust gas can not flow into the combustion chamber (24) side through the through hole (23a) on the partition (23) that is penetrated by the electric heater (26) from the decomposition chamber (22), the The through hole (23a) of the above-mentioned partition (23) is completely closed, and the electric heater (26) is fixed on the partition (23). In this case, when the electric heater (26) is energized and heated, the _Al2O3 protection tube (26b) of the electric heater (26) is damaged due to the constraint of the partition (23) during _thermal expansion, but the electric heater (26 ) is arranged in parallel with respect to the partition wall (23), the electric heater (26) is free relative to the partition wall (23), and will not be damaged when energized and heated.

【Effect of invention】

As mentioned above, the present invention can provide a pest control method and a pest control device that have a high rate of pest control for PFC components that are difficult to control at low temperatures and can eliminate pests with low energy consumption.

【Brief description of the drawings】

【Attachment 1】

(A) represents the structural representation of the pest removal device in Embodiment 1 of the present invention.

(B) represents the structural representation of a kind of deformation of the decontamination device of embodiment 1 of the present invention.

(C) represents the structural representation of the pest removal device in Embodiment 3 of the present invention.

【Attachment 2】

(A) (B) The top view and the front sectional view of the pest removal device in Embodiment 4 of the present invention.

(C) Front cross-sectional view of another structure of the device of the above-mentioned embodiment 4.

【Attachment 3】

Represent the schematic front sectional view of the structure of the decontamination device of Embodiment 5 of the present invention.

【Attachment 4】

The side sectional view of the decomposition combustion tower in the accompanying drawing 3 device.

【Attachment 5】

The top sectional view of the decomposition combustion tower in the accompanying drawing 3 device.

【Attachment 6】

Represent the front sectional view of another kind of structure of accompanying drawing 3 harm removal device of the present invention.

【Description of Symbols Used in Drawings】

(1) Front water scrubber (first scrubber)

(2) PFC decomposing tower

(3) Rear water scrubber (second scrubber)

(4) Treated gas combustion tower

(5) Introductory pipe containing PFC treated gas

(6) Reducing atmosphere forming agent introduction tube

(7) Suction fan

(8) Exhaust pipe directly to the atmosphere

(9) Air inlet pipe

(10) sink

(11) Gas decomposition combustion tower

(12) Gas decomposition chamber

(13) next door

(14) Combustion chamber

(15) Lined with ceramic insulation layer

(16) heater

(17) Hydrocarbon gas introduction pipe

(18)Air inlet pipe

(21) Gas decomposition combustion tower

(22) Gas decomposition chamber

(23) next door

(24) Combustion chamber

(26) electric heater

(29)Heat Resistant Rod

Claims (27)

1. A method for eliminating harmful effects of perfluorocarbons or perfluorinated compounds, characterized in that in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment, mixing is 0.1 to 3 mol relative to PFC1mol CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₄ H ₁₀ represented by hydrocarbon gas or ammonia gas or two or more gases, at 600 ~ 1300 ° C, in a non-oxidizing atmosphere Thermal decomposition of the mixed gas. 2. The method for eliminating harmful effects of perfluorocarbons or perfluorinated compounds according to claim 1, characterized in that water is added to the above-mentioned mixed gas. 3. A perfluorocarbon or perfluorochemical detoxification method, characterized in that it consists of the following steps: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A step of thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) a step of burning the pyrolysis gas to remove flammable components from the pyrolysis gas, and (c) A step of removing fluoride produced by thermal decomposition by washing with water or by chemical adsorption. 4. A perfluorocarbon or perfluorinated compound detoxification method, characterized in that it consists of the following steps: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H ₁₀ with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment. A step of thermally decomposing the above-mentioned mixed gas under a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas or ammonia gas shown; (b) a step of washing or chemical adsorption to remove fluoride produced by thermal decomposition, and (c) A step of burning the pyrolysis gas to remove combustible components in the pyrolysis gas. 5. A method for eliminating harmful effects of perfluorocarbons or perfluorinated compounds, characterized in that it consists of the following steps: (a) The step of washing the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the manufacturing equipment with water; (b) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , and C ₃ H with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the first water scrubber _8. A step of thermally decomposing the above-mentioned mixed gas under a non-oxidizing atmosphere at 600-1300°C for any one or two or more of hydrocarbon gas represented by C ₄ H ₁₀ or ammonia gas; (c) a step of washing or chemical adsorption to remove fluoride produced by thermal decomposition; (d) A step of burning the pyrolysis gas to remove combustible components in the pyrolysis gas. 6. A perfluorocarbon or perfluorochemical detoxification method, characterized in that it consists of the following steps: (a) The step of washing the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the manufacturing equipment with water; (b) Mix any one or two or more of hydrocarbon gas or ammonia gas represented by CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H ₁₀ at 0.1 to 3 mol relative to 1 mol of PFC, at 600 The step of thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at ~1300°C; (c) a step of burning the pyrolysis gas to remove flammable components from the pyrolysis gas, and (d) A step of removing fluoride produced by thermal decomposition by washing with water or by chemical adsorption. 7. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300 ° C for one or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) be connected to the downstream side of the above-mentioned gas decomposition tower, and burn the combustible components in the treated gas decomposed in the decomposition tower; (c) the heater arranged in the gas decomposition tower; (d) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (e) air induction pipes supplying air to the combustion tower; and (f) The second water scrubber arranged on the downstream side of the combustion tower. 8. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300 ° C for one or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (c) the second water scrubber arranged on the downstream side of the gas decomposition tower; (d) a combustion tower connected to the downstream side of the second water scrubber to burn the combustible components in the scrubbing gas washed by the second water scrubber; (e) heaters arranged in the gas decomposition tower; and (f) An air introduction pipe for supplying air to the combustion tower. 9. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300 ° C for one or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) a combustion tower connected to the downstream side of the above-mentioned gas decomposition tower to burn the flammable components in the gas after decomposition in the gas decomposition tower; (c) the heater arranged in the gas decomposition tower; (d) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (e) air induction pipes supplying air to the combustion tower; and (f) An adsorption tower arranged on the downstream side of the combustion tower and filled with granular calcium oxide or calcium carbonate. 10. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300 ° C for one or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (c) be arranged on the gas decomposition tower downstream side, be filled with the adsorption tower of granular calcium oxide or calcium carbonate; (d) It is connected to the downstream side of the above-mentioned adsorption tower, so that the adsorption tower discharges the combustion tower that combustible components in the adsorption treatment gas burn; (e) heaters arranged in the gas decomposition tower; and (f) An air introduction pipe for supplying air to the combustion tower. 11. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The decomposition combustion tower is composed of Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H ₁₀ with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment. A gas decomposition chamber for thermally decomposing the above-mentioned mixed gas under a non-oxidizing atmosphere at 600-1300 ° C, and Combustion chamber for combusting combustible components in the above-mentioned decomposition chamber to decompose and process gas, The above-mentioned decomposition chamber and combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at the upper end of the partition wall; (b) Heaters installed in the gas decomposition chamber and combustion chamber; (c) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (d) air intake ducts for supplying air to the combustion chamber; and (e) The second water scrubber arranged on the downstream side of the gas decomposition combustion tower. 12. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The decomposition combustion tower is composed of: Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H ₁₀ with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment. A gas decomposition chamber for thermally decomposing the above-mentioned mixed gas under a non-oxidizing atmosphere at 600-1300 ° C, and A combustion chamber for burning combustible components in the gas decomposed by the above decomposition chamber, The decomposition chamber and the combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at their upper ends; (b) Heaters installed in the gas decomposition chamber and combustion chamber; (c) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (d) air intake ducts for supplying air into the combustion chamber; and (e) An adsorption tower that is arranged on the downstream side of the gas decomposition combustion tower and is filled with granular calcium oxide or calcium carbonate. 13. The perfluorocarbon or perfluorinated compound detoxification device according to any one of claims 7-12, characterized in that the heater is installed horizontally in the gas decomposition chamber and the combustion chamber. 14. A perfluorocarbon detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the manufacturing device; (b) The gas decomposition combustion tower is composed of: Connected to the upper end of the above-mentioned first water scrubber, mix CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₄ with respect to 1 mol of PFC in the treated gas washed by the first water scrubber Any one or two or more of hydrocarbon gas or ammonia gas shown in H ₁₀ , a gas decomposition chamber for thermally decomposing the above-mentioned mixed gas at 600-1300°C in a non-oxidizing atmosphere, and Combustion chamber for combusting combustible components in the gas decomposed and treated by the above decomposition chamber, The above-mentioned gas decomposition chamber and combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at their upper ends; (c) heaters installed horizontally in the gas decomposition chamber and combustion chamber; (d) a grate arranged horizontally below the heater in the gas decomposition chamber and combustion chamber; (e) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (f) Air inlet pipes for supplying air to the combustion chamber; (g) a second water scrubber connected to the lower end of the combustion chamber; and (h) A water tank for the first water scrubber and the second water scrubber is provided. 15. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing fluoride before the gas is decomposed; (b) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , and C ₃ H with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the first water scrubber _8. A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas represented by C ₄ H ₁₀ or ammonia gas; (c) A combustion tower that is connected to the downstream side of the above-mentioned gas decomposition tower and burns the flammable components in the gas after the decomposition treatment in the gas decomposition tower; (d) the heater arranged in the gas decomposition tower; (e) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (f) air intake pipes for supplying air to the combustion tower; and (g) The second water scrubber arranged on the downstream side of the combustion tower. 16. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing fluoride before the gas is decomposed; (b) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , and C ₃ H with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the first water scrubber _8. A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas represented by C ₄ H ₁₀ or ammonia gas; (c) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (d) the second water scrubber that is arranged on the gas decomposition tower downstream side; (e) a combustion tower that is connected to the downstream side of the second water scrubber to burn the combustible components in the scrubbing gas washed by the second water scrubber; (f) heaters arranged in the gas decomposition tower; and (g) An air introduction pipe for supplying air to the combustion tower. 17. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing fluoride before the gas is decomposed; (b) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , and C ₃ H with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the first water scrubber _8. A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas represented by C ₄ H ₁₀ or ammonia gas; (c) A combustion tower that is connected to the downstream side of the above-mentioned gas decomposition tower and burns the flammable components in the gas after the decomposition treatment in the gas decomposition tower; (d) the heater arranged in the gas decomposition tower; (e) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (f) air intake pipes for supplying air to the combustion tower; and (g) An adsorption tower arranged on the downstream side of the combustion tower and filled with granular calcium oxide or calcium carbonate. 18. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing fluoride before the gas is decomposed; (b) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , and C ₃ H with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the first water scrubber _8. A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas represented by C ₄ H ₁₀ or ammonia gas; (c) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (d) the adsorption tower that is arranged on the downstream side of the gas decomposition tower and is filled with granular calcium oxide or calcium carbonate; (e) It is connected to the downstream side of the above-mentioned adsorption tower, so that the adsorption tower discharges the combustion tower that combustible components in the adsorption treatment gas burn; (f) heaters arranged in the gas decomposition tower; and (g) An air introduction pipe for supplying air to the combustion tower. 19. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing fluoride before the gas is decomposed; (b) The gas decomposition combustion tower is composed of In the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the first water scrubber, 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C A gas decomposition chamber for thermally decomposing the above _{-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of hydrocarbon gas or ammonia gas represented by 4H10 ,} and Combustion chamber for combusting combustible components in gas decomposed by the above-mentioned gas decomposition chamber, The above-mentioned gas decomposition chamber and the combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at the upper end of the partition wall; (c) Heaters installed in the gas decomposition chamber and combustion chamber; (d) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (e) air intake ducts for supplying air to the combustion chamber; and (f) The second water scrubber arranged on the downstream side of the gas decomposition combustion tower. 20. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing fluoride before the gas is decomposed; (b) The gas decomposition combustion tower is composed of In the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the first water scrubber, 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C A gas decomposition chamber for thermally decomposing the above _{-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of hydrocarbon gas or ammonia gas represented by 4H10 ,} and Combustion chamber for combusting combustible components in gas decomposed by the above-mentioned gas decomposition chamber, The above-mentioned gas decomposition chamber and the combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at the upper end of the partition wall; (c) Heaters installed in the gas decomposition chamber and combustion chamber; (d) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (e) air intake ducts for supplying air to the combustion chamber; and (f) The adsorption tower that is arranged on the downstream side of the gas decomposition combustion tower and is filled with granular calcium oxide or calcium carbonate. 21. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) be connected with the downstream side of above-mentioned gas decomposition tower, make the combustible component in gas decomposition treatment in the gas decomposition tower burn the combustible component; (c) the heater arranged in the gas decomposition tower; (d) the grate horizontally arranged below the heater in the gas decomposition tower; (e) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (f) air intake pipes for supplying air to the combustion tower, and (g) The second water scrubber arranged on the downstream side of the combustion tower. 22. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (c) the second water scrubber arranged on the downstream side of the gas decomposition tower; (d) a combustion tower that is connected to the downstream side of the second water scrubber to burn combustible components in the scrubbing gas washed by the second water scrubber; (e) the heater arranged in the gas decomposition tower; (f) the grate horizontally arranged below the heater in the gas decomposition tower; and (g) An air introduction pipe for supplying air to the combustion chamber. 23. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) be connected with the downstream side of above-mentioned gas decomposition tower, make the combustible component in gas decomposition treatment in the gas decomposition tower burn the combustible component; (c) the heater arranged in the gas decomposition tower; (d) the grate horizontally arranged below the heater in the gas decomposition tower; (e) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (f) an air intake pipe for supplying air to the combustion chamber, and (g) An adsorption tower arranged on the downstream side of the combustion tower and filled with granular calcium oxide or calcium carbonate. 24. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H with respect to 1 mol of PFC in the gas to be treated containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment A gas decomposition tower for thermally decomposing the above-mentioned mixed gas in a non-oxidizing atmosphere at 600-1300°C for any one or two or more of the hydrocarbon gas or ammonia gas shown in ₁₀ ; (b) a reducing atmosphere forming agent introduction pipe for supplying the reducing atmosphere forming agent to the gas decomposition tower; (c) be arranged on the gas decomposition tower downstream side, be filled with the adsorption tower of granular calcium oxide or calcium carbonate; (d) A combustion tower that is connected to the downstream side of the above-mentioned adsorption tower to burn combustible components in the adsorption treatment gas discharged from the adsorption tower; (e) the heater arranged in the gas decomposition tower; (f) the grate horizontally arranged below the heater in the gas decomposition tower; and (g) An air introduction pipe for supplying air to the combustion chamber. 25. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The gas decomposition combustion tower is composed of Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H ₁₀ with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment. Any one or two or more of hydrocarbon gas or ammonia gas, a gas decomposition chamber for thermally decomposing the above-mentioned mixed gas at 600-1300°C in a non-oxidizing atmosphere, and Combustion chamber for combusting combustible components in gas decomposed by the above-mentioned gas decomposition chamber, The above-mentioned gas decomposition chamber and the combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at the upper end of the partition wall; (b) Heaters installed in the gas decomposition chamber and combustion chamber; (c) The grate arranged horizontally below the heater in the gas decomposition chamber and the combustion chamber; (d) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (e) air intake ducts for supplying air to the combustion chamber; and (f) The second water scrubber arranged on the downstream side of the gas decomposition combustion tower. 26. A perfluorocarbon or perfluorinated compound detoxification device, characterized in that it consists of the following equipment: (a) The gas decomposition combustion tower is composed of Mix 0.1 to 3 mol of CH ₄ , C ₂ H ₆ , C ₃ H ₈ , and C ₄ H ₁₀ with respect to 1 mol of PFC in the treated gas containing perfluorocarbons or perfluorinated compounds discharged from manufacturing equipment. Any one or two or more of hydrocarbon gas or ammonia gas, a gas decomposition chamber for thermally decomposing the above-mentioned mixed gas at 600-1300°C in a non-oxidizing atmosphere, and Combustion chamber for combusting combustible components in gas decomposed by the above-mentioned gas decomposition chamber, The above-mentioned gas decomposition chamber and the combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at the upper end of the partition wall; (b) Heaters installed in the gas decomposition chamber and combustion chamber; (c) The grate arranged horizontally below the heater in the gas decomposition chamber and the combustion chamber; (d) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (e) air intake ducts for supplying air to the combustion chamber; and (f) The adsorption tower that is arranged on the downstream side of the gas decomposition combustion tower and is filled with granular calcium oxide or calcium carbonate. 27. A perfluorocarbon detoxification device, characterized in that it consists of the following equipment: (a) The first water scrubber for washing the treated gas containing perfluorocarbons or perfluorinated compounds discharged from the manufacturing device; (b) The gas decomposition combustion tower is composed of: Connected to the upper end of the above-mentioned first water scrubber, mix CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₄ with respect to 1 mol of PFC in the treated gas washed by the first water scrubber Any one or two or more of hydrocarbon gas or ammonia gas shown in H ₁₀ , a gas decomposition chamber for thermally decomposing the above-mentioned mixed gas at 600-1300°C in a non-oxidizing atmosphere, and Combustion chamber for combusting combustible components in the gas decomposed and treated by the above decomposition chamber, The above-mentioned gas decomposition chamber and combustion chamber are integrated through a heat-resistant partition wall and communicate with each other at their upper ends; (c) heaters installed horizontally in the gas decomposition chamber and combustion chamber; (d) a grate arranged horizontally below the heater in the gas decomposition chamber and combustion chamber; (e) a reducing atmosphere forming agent introduction pipe for supplying a reducing atmosphere forming agent to the gas decomposition chamber; (f) Air inlet pipes for supplying air to the combustion chamber; (g) a second water scrubber connected to the lower end of the combustion chamber; and (h) A water tank for the first water scrubber and the second water scrubber is provided.

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