TW201433351A - Device for treating perfluoro compounds and method for treating perfluoro compounds - Google Patents

Abstract

This device for treating perfluoro compounds is provided with: a pre-treatment means a first heater (221) hat heats water and a device entrance exhaust gas a second heater (222) that generates decomposition gas containing an acidic gas by means of hydrolysis of perfluoro compounds by means of a catalyst a heat exchanger (231) that exchanges heat between the device entrance exhaust gas and the decomposition gas an acid component elimination device (232) that performs dry elimination of the acid component from the decomposition gas and a particle trap (237). The pre-treatment means and the first heater (221) are arrayed in the given order along one long side of a rectangular region within the rectangular region seen from above, the second heater (222), acid component elimination device (232), and particle trap (237) are arrayed along the other long side of the rectangular region within the rectangular region seen from above in the reverse order from the order of arraying of the pre-treatment means and the first heater (221).

Description

Fluoride treatment device and method for treating perfluorinated material

The present invention is, for example, a treatment apparatus for perfluorinated materials for treating perfluorinated substances, and the like.

For example, in a manufacturing process of a semiconductor device or a liquid crystal device, etching or cleaning is performed in order to form a fine pattern. There are many occasions where fluoride is used at this time. Further, since perfluorinated materials are generally stable and harmless to the human body, others are used, for example, in refrigerant applications for air conditioners.

However, if these emissions of superfluoride are emitted into the atmosphere, they will have a great impact on the global environment. That is, because it has a long-term stability in the atmosphere and has a large global warming coefficient, it is a major cause of global warming. As mentioned earlier, perfluorinated materials are generally stable in nature and their effects will last for a considerable period of time.

In order to prevent the global environment from being affected, it is necessary to decompose the used perfluorinated materials into a state that is harmless to the global environment and then discharge them into the atmosphere.

Patent Document 1 discloses that fluorine is contained only as a halogen. The gas stream of the fluorine-containing compound is contacted with a catalyst composed of aluminum, such as a catalyst composed of aluminum and nickel, aluminum and zinc, and aluminum and titanium, at a temperature of about 200 to 800 ° C in the presence of steam. A method of decomposing a fluorine-containing compound in which a fluorine in a gas stream is converted into hydrogen fluoride.

Further, Patent Document 2 discloses that a discharge gas containing a perfluorinated substance is provided to be provided with a catalyst layer, a perfluorination decomposition apparatus for decomposing a perfluorinated substance, and a discharge discharged by the perfluorination decomposition apparatus are removed. A perfluorinated material treatment apparatus for an acid removal device of a first reaction product produced by reacting an acidic substance contained in a gas with a calcium salt.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-224926

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-246485

However, in the case where a gas containing a perfluoride is to be processed in a large amount, the apparatus is required to be large, and when HF (hydrogen fluoride) or the like is generated as a reactant, a large amount of water is necessary for removing HF or the like. Therefore, there is also the problem of having to deal with HF-containing drainage.

The present invention has been made in view of the aforementioned problems of the prior art.

That is, an object of the present invention is to provide a treatment apparatus for a perfluorinated product which can process a large amount of perfluorinated material and which is easy to miniaturize and which has a small amount of waste water discharged.

As described above, according to the present invention, there is provided a apparatus for treating a perfluorinated product, comprising: a pretreatment means for removing solid components and/or mist particles from a gas containing perfluorate, and heating a gas containing perfluorate and water a heating means, a second heating means for containing a perfluorinated gas and water heated by the first heating means, and a hydrolyzate by a predetermined catalyst to generate a decomposition gas containing an acid gas, The first stage of the first heating means and the second stage of the second heating means are disposed between the desulfurized gas-mixed water before flowing into the first heating means and the decomposition gas after flowing out of the second heating means. Heat exchange means for heat exchange, acid component removal means for dry removal of acid component by decomposition gas after flowing out from the heat exchange means, and post-treatment for removing solid component by exhaust gas after dry removal of acid component by acid component removal means The means, the pretreatment means, and the first heating means are viewed from above in a rectangular region and along one long side of the rectangular region The second heating means, the acid component removing means, and the post-processing means are arranged inside the rectangular region as viewed from above and along the other long side of the rectangular region, and are arranged with the pretreatment means and the first heating means. The order of the opposite order is arranged separately.

Here, the heat exchange means to the other side of the rectangular area It is preferable that the long side is disposed between the second heating means and the acid component removing means, and the pipe connected to the post-treatment means by the acid component removing means is disposed along the other long side of the rectangular region. It is preferable to have fins for cooling the exhaust gas.

Furthermore, the present invention further includes a drug supply means for supplying a drug for dry removal of an acid component from above the acid component removal means, a drug discharge means for discharging the drug from the lower side of the acid component removal means, and a decomposition gas for introducing the acid component removal means. It is preferably introduced from the lower side of the acid component removing means and discharged from the upper side of the acid component removing means.

Further, the water and/or the machine-driven air to be mixed by the heat exchange means are supplied along the short side of one of the rectangular regions, and the second heating means is disposed in the other of the rectangular regions. The side is preferred.

Further, according to the present invention, there is provided a method for treating a perfluorinated product, comprising: a pretreatment step of removing a solid component and/or a mist particle from a gas containing a perfluorate, heating a gas containing perfluorate, and water The first heating step, further heating the perfluorinated gas and water heated by the first heating step, and simultaneously hydrolyzing the perfluorate by a predetermined catalyst to generate a second heating of the decomposition gas containing the acid gas In the step of the first stage of the first heating step and the second stage of the second heating step, the perfluorinated gas-containing mixed water before flowing into the first heating step is simultaneously performed with the decomposition gas after flowing out from the second heating step. Heat exchange step of heat exchange, acid component removal step of dry removal of acid component by decomposition gas after flowing out from the heat exchange step, by addition of acid component The post-treatment step of removing the solid component from the exhaust gas after the acid component is dry-removed, the pre-treatment step and the first heating step are viewed from above in the rectangular region and along the long side of one of the rectangular regions The position is sequentially performed, and the second heating step, the acid component removing step, and the post-treatment step are viewed from above in the rectangular region and along the other long side of the rectangular region, and the pretreatment step and the first heating are performed. The order of the steps is reversed in the order of the positions.

The pretreatment means and the first heating means are arranged in the rectangular region from the top and along the long side of the rectangular region, and the second heating means, the acid component removing means, and the post-processing means are viewed from above. The inside of the rectangular region and along the other long side of the rectangular region are arranged in the reverse order of the arrangement of the pretreatment means and the first heating means, and the respective devices are arranged in a U-shape in accordance with the order of gas flow. shape. As a result, for example, when the respective devices are arranged in a straight line, the length of the treatment device for the perfluorinated material as viewed from above becomes smaller and the area is also smaller.

The heat exchange means is disposed between the second heating means and the acid component removing means on the other long side of the rectangular region, and the area occupied by the processing device for the perfluorinated material is further reduced.

The piping which is connected to the post-treatment means by the acid component removing means is disposed along the other long side of the rectangular region, and is provided with a heat radiating fin for cooling the exhaust gas, so that the temperature of the exhaust gas is easily lowered.

Further, the drug supply means for supplying the drug for dry removal of the acid component by the acid component removing means, the drug discharging means for discharging the drug from the lower side of the acid component removing means, and the decomposition gas for introducing the acid component removing means are further provided. It is introduced from the lower side of the acid component removing means and discharged from the upper side of the acid component removing means, whereby the drug can be exchanged by a simple system, and the amount of the drug can be reduced.

The water and/or machine-type driving air mixed by the heat exchange means is supplied from a position along the short side of one of the rectangular regions, and the second heating means is disposed on the other short side of the rectangular region. In addition, it is possible to further reduce the size of the device for perfluorination, and it is possible to suppress the application of water or the like from being affected by the heat released by the second heating means.

The pretreatment step and the first heating step are sequentially performed inside the rectangular region and along the one long side of the rectangular region, and the second heating step, the acid component removing step, and the post-processing step are performed from above. Looking at the inside of the rectangular region and along the other long side of the rectangular region, respectively, in the order opposite to the order of the pre-processing step and the first heating step, the treatment of the perfluorinated material can be made smaller. Within the area.

1‧‧‧Semiconductor manufacturing equipment

2‧‧‧Perfluoride treatment unit

3‧‧‧Acid scrubber

21‧‧‧Pre-processing unit

22‧‧‧ Perfluorinated decomposition unit

23‧‧‧HF adsorption unit

24‧‧‧Control unit

211‧‧‧Inlet heater

212‧‧‧Filter

221‧‧‧1st heater

222‧‧‧2nd heater

231‧‧‧ heat exchanger

232‧‧‧acid component removal device

233‧‧‧ejector

Fig. 1 is a view showing the overall configuration of a semiconductor manufacturing plant to which the apparatus for treating perfluorinated materials of the present embodiment is applied.

Fig. 2 is a view showing the outline of a processing apparatus for perfluorinated materials of the present embodiment. The map of the composition.

Fig. 3 is a view showing each of the machines constituting the apparatus for treating perfluorinated materials of the present embodiment.

Fig. 4 is a graph showing the relationship between the reaction temperature and the decomposition rate of perfluorinated materials.

Fig. 5 is a flow chart showing the operation of the apparatus for treating perfluorinated materials.

Figure 6 is a diagram of the actual production of perfluorinated processing apparatus as seen from above.

Fig. 7 is a view showing an apparatus for actually processing a perfluorinated product seen from the direction of VII of Fig. 6.

Hereinafter, the embodiment of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the spirit and scope of the invention. In addition, the drawings used are for the purpose of illustrating the embodiment, and do not represent actual size.

<Description of the overall structure of the semiconductor manufacturing plant>

Fig. 1 is a view showing the overall configuration of a semiconductor manufacturing plant to which the apparatus for treating perfluorinated materials of the present embodiment is applied.

As shown in the figure, the semiconductor manufacturing plant of the present embodiment includes a semiconductor manufacturing facility for manufacturing a semiconductor, a processing device 2 for decomposing a perfluorinated perfluorate, and a pickling gas for trapping acid gas. Device 3.

The semiconductor manufacturing equipment 1, usually a clean room, in the example shown, has the etched semiconductor. The polycrystalline germanium P-Si etcher 11 etches an oxide film etcher 12 of an oxide film such as ruthenium oxide (SiO ₂ ) of an insulating film, and a metal etcher 13 for etching a metal film.

The P-Si etcher 11, the oxide film etcher 12, and the metal etcher 13, are dry etching (dry etching) devices, for example, reactive ion etching using a reactive etching gas in a process vacuum chamber ( RIE: Reactive Ion Etching) device.

The etching gas used in the P-Si etcher 11, the oxide film etcher 12, and the metal etcher 13 is different, and the gas discharged after the dry etching of each device contains various perfluorides resulting from the etching gas (hereinafter, , also known as PFC (perfluorocompound) or CHF ₃ and so on. Examples of the perfluorinated compound include CF ₄ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , C ₅ F ₈ , SF ₆ and the like. Then, the gas containing the perfluorate emission, that is, the etching exhaust gas, is removed by the toxic gas detoxification device 14 after the toxic gas such as chlorine (Cl ₂ ) gas is discharged to the semiconductor manufacturing equipment 1 through the collecting duct 15 . In the present embodiment, the etching exhaust gas discharged from the outside of the semiconductor manufacturing apparatus 1 is, for example, 99% of the N ₂ (nitrogen) gas of the carrier gas, and contains 1% of a perfluorinated substance or the like. In the present embodiment, the perfluorinated material contained in the etching exhaust gas is preferably 1% or less. Further, the flow rate of the discharged etching exhaust gas is, for example, 3000 L/min to 3500 L/min.

Perfluorinated treatment device 2, as described later, by The perfluorinated material contained in the etching exhaust gas discharged from the semiconductor manufacturing equipment 1 is decomposed to remove the perfluorinated material, and then discharged as an exhaust gas. Therefore, the etching exhaust gas collected through the conduits is discharged from the respective devices of the semiconductor manufacturing equipment 1, and is introduced into the processing device 2 for perfluorinated products through the three-way valve 4. The perfluorinated treatment device 2 is not necessarily provided in the clean room, and is usually disposed outside the semiconductor manufacturing equipment 1.

The acid scrubber 3 traps acid gases. Next, the harmless gas after the acid gas is collected is discharged to the outside of the semiconductor manufacturing plant. The role of the acid scrubber 3 is to trap the perfluorinated material even when the perfluorinated material is completely removed by the treatment device 2 for the perfluorinated product. Further, when the treatment device for the perfluorinated product 2 fails, the role of the backup device of the fluoride treatment device 2 is also assumed. In short, in a normal state, the gas containing perfluoride is introduced into the perfluorinated treatment device 2 by the three-way valve 4, and the perfluorinated material is decomposed and treated by the perfluorinated treatment device 2. However, when the treatment device for the perfluorinated product 2 fails, the three-way valve 4 is switched, and the gas containing the perfluorate is directly introduced into the acid scrubber 3.

Further, although not shown in FIG. 1, an alkaline scrubber that traps the acid gas contained in the etching exhaust gas discharged from the semiconductor manufacturing equipment 1 may be provided on the upstream side of the three-way valve 4.

<Description of Configuration of Fluoride Treatment Device>

Hereinafter, the processing device 2 for perfluorinated materials will be described in more detail.

Figure 2 is a schematic view showing the apparatus for treating perfluorinated material 2 of the present embodiment. Slightly composed of the map.

As shown in the figure, the perfluorinated material processing apparatus 2 includes a pretreatment unit 21 that preliminarily introduces a device inlet exhaust gas (etched exhaust gas) to be introduced, and an apparatus inlet exhaust gas which is decomposed in the pretreatment unit 21 to be pretreated. The perfluorinated perfluorination decomposition unit 22 and the HF adsorption unit 23 that performs dry removal by adsorbing the decomposition gas of HF (hydrogen fluoride) generated when the perfluorochemical decomposition unit 22 decomposes the perfluorate. Then, the exhaust gas is detoxified by the inlet of each of the unit processing apparatuses, and then discharged as an exhaust gas to the outside of the treatment device 2 for perfluorinated substances.

Fig. 3 is a view showing the respective machines constituting the processing apparatus 2 for perfluorinated materials of the present embodiment.

As described with reference to Fig. 2, the perfluorinated treatment apparatus 2 mainly includes a pretreatment unit 21, a perfluorination decomposition unit 22, and an HF adsorption unit 23. Further, as shown in the figure, the perfluorinated material processing apparatus 2 includes a control unit 24 for controlling each of the devices and valves (not shown) provided in the apparatus for processing fluoride.

The pretreatment unit 21 includes an inlet heater 211 for preheating the exhaust gas of the device inlet, and a filter 212 for removing the fine particles.

The inlet heater 211 evaporates minute water droplets (mist particles) contained in the device inlet exhaust gas by discharging the gas from the inlet of the preheating device. The inlet heater 211 is provided with a heater 211a around the piping through which the exhaust gas passes through the apparatus inlet. Next, the device inlet vents gas and passes through the inlet When the heater 211 is heated by the heater 211a, it is preheated to a temperature at which the mist particles evaporate. At this time, the temperature of the exhaust gas of the preheated device inlet may be, for example, 60 °C. Thereby, it is possible to suppress the next filter 212 from being occluded by the mist particles.

The filter 212 removes fine particles as solid components contained in the exhaust gas of the device inlet. In the semiconductor manufacturing equipment 1, fine particles such as ruthenium oxide which are cut off during the dry etching described above are generated. Then, the fine particles are mixed into the device inlet exhaust gas, so they are removed by the filter 212. The filter 212 is not particularly limited as long as it can allow the exhaust gas of the device to pass through while collecting the fine particles, and for example, a mesh filter or the like can be used.

The pretreatment unit 21 can be regarded as a pretreatment means for removing solid components and/or mist particles from the inlet of the device.

Further, in the present embodiment, air is introduced between the inlet heater 211 and the filter 212. In order to suppress the generation of carbon monoxide by the next-perfluoride decomposition unit 22, and oxygen is necessary, the air is mixed with the device inlet exhaust gas at this stage.

Further, in the present embodiment, as will be described later in detail, the exhaust gas passing through the apparatus inlet after the filter 212 once enters the heat exchanger 231. The device inlet exhaust gas is then heated by heat exchange by heat exchanger 231. Further, at this time, the water necessary for the reaction for decomposing the perfluoride by the next perfluorination decomposition unit 22 is added in a liquid state. This water is heated in the heat exchanger 231 together with the device inlet exhaust gas to become the water vapor of the gas. It is then mixed with the device inlet exhaust gas and transferred. In this embodiment In the state, pure water is used for the water, and the amount added is an amount corresponding to the reaction formula described later, and is, for example, 350 mL/min. Further, this water may be previously heated and added to the heat exchanger 231 in the form of water vapor.

The perfluorination decomposition unit 22 includes a first heater 221 which is an example of a first heating means that discharges gas and water at the inlet of the heating device, and further heats the inlet gas and water of the apparatus heated by the first heater 221 while borrowing The second heater 222 which is an example of the second heating means for generating a decomposition gas containing an acid gas by decomposing the perfluorinated material by a predetermined catalyst.

The first heater 221 is internally provided with a heater 221a, and the heater 221a, the heater inlet vent gas, and the heat exchanger 231 are added to become water vapor. The gas is discharged through the device inlet after the first heater 221, for example, at 450 ° C to 500 ° C. In the present embodiment, the first heater 221 that makes the flow path of the device inlet exhaust gas into a horizontal horizontal heater is used.

The second heater 222 discharges gas from the inlet of the upper introduction device, and firstly, the heater 222a is provided inside, and the gas and water vapor are discharged from the inlet of the heating device. Thereby, the device inlet exhaust gas, for example, is heated to 750 °C.

Then, the gas is discharged from the inlet of the device to be heated, and the catalyst layer 222b disposed below the second heater 222 is decomposed by reacting with water (water vapor) mixed with the exhaust gas of the device inlet.

The decomposition reaction at this time is taken as a perfluorinated product, and in the case of CF ₄ , CHF ₃ , C ₂ F ₆ and SF ₆ , the reaction formula is shown as follows.

CF ₄ +2H ₂ O → CO ₂ +4HF...(1)

CHF ₃ +(1/2)O ₂ +H ₂ O → CO ₂ +3HF...(2)

C ₂ F ₆ +3H ₂ O+(1/2)O ₂ → 2CO ₂ +6HF...(3)

SF ₆ +3H ₂ O → SO ₃ +6HF...(4)

From the above formulas (1) to (4), it is understood that the perfluorinated product is a decomposition gas of HF (hydrogen fluoride) containing an acid component by a hydrolysis reaction. Further, in this case, HF may be regarded as an acid gas contained in the decomposition gas.

Fig. 4 is a graph showing the relationship between the reaction temperature and the decomposition rate of perfluorinated materials.

Here, as the perfluorinated material contained in the etching exhaust gas, CF ₄ , CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , C ₅ F ₈ , SF ₆ , NF ₃ can be exemplified. In addition, although it is not a perfluoride, the component contained in the gas discharged from the semiconductor manufacturing equipment 1 also shows CO.

As shown in the figure, no matter what kind of component is almost 100% decomposition rate in the vicinity of 750 ° C, the perfluorinated substance or the like can be almost completely removed by reacting at a temperature of 750 ° C.

Further, as the catalyst constituting the catalyst layer 222b, in the present embodiment, Al ₂ O ₃ (alumina) may be used containing Zn (zinc), Ni (nickel), Ti (titanium), F (fluorine), Sn. (Thin), Co (cobalt), Zr (zirconium), Ce (铈), Si (矽) and other oxides. More specifically, for example, a composition composed of 80% by weight of Al ₂ O ₃ (alumina) and 20% by weight of NiO (nickel oxide) can be used.

The HF-containing decomposition gas after the second heater 222 is decomposed with the perfluorate is discharged from the lower side of the second heater 222 and sent Go to the next HF adsorption unit 23. Moreover, the temperature of the decomposition gas discharged from the second heater 222 at this time is about 600 ° C to 700 ° C.

The HF adsorption unit 23 includes a gas mixture water containing perfluorinated material that is disposed in the front stage of the first heater 221 and the second stage of the second heater 222 before flowing into the first heater 221, and is provided by the second heater. The heat exchanger 231 which is an example of a heat exchange means for exchanging heat between the decomposition gases after the 222 outflow, and the decomposition gas which flows out of the heat exchanger 231 reacts the calcium component with the calcium salt to perform dry removal as an acid component. An acid component removing device 232 as an example of the removing means, and an ejector 233 as an example of the exhaust gas discharging means for discharging the exhaust gas after the acid component is dry-removed by the acid component removing means 232.

In addition, the HF adsorption unit 23 further includes a drug supply device 234 as an example of a drug supply means for supplying a calcium salt of a drug for dry removal of HF from above the acid component removal device 232, and is discharged from the lower side of the acid component removal device 232. The drug discharge device 235 which is one example of the drug discharge means of the used calcium salt, the HF concentration sensor 236 which monitors the concentration of HF contained in the gas discharged from the acid component removal device 232, and the HF concentration sense Between the detector 236 and the ejector 233, a solids trap 237 of the solid component removal device 232 is removed.

The heat exchanger 231 exchanges heat between the high-temperature decomposition gas discharged from the second heater 222 and the low-temperature device inlet exhaust gas before being introduced into the first heater 221. Thereby, the temperature of the decomposition gas is lowered, and the device before being introduced into the first heater 221 is introduced. The temperature of the exhaust gas rises. Further, as described above, the water added to the heat exchanger 231 evaporates into water vapor.

The temperature of the decomposition gas after passing through the heat exchanger 231 is lowered to about 300 ° C to 500 ° C, and the gas is discharged through the inlet of the device after the heat exchanger 231, and the temperature is raised to about 200 ° C to 300 ° C.

The heat exchanger 231 is not particularly limited, and a plate type heat exchanger in which two plates are alternately arranged, a flow path is formed between the plates, and heat exchange between the device inlet exhaust gas and the decomposition gas is performed, or a shell is used. A heat exchanger in the form of a shell and a tube that exchanges gas or decomposes gas at a device inlet and a plurality of tubes (heat transfer tubes), respectively, through heat exchange between the shells and the tubes (heat transfer tubes). Further, a double tube heat exchanger in which a double tube structure is formed, a decomposition gas having a high temperature is circulated in the inner tube, and a gas is discharged through the inlet of the apparatus at a low temperature in the outer tube may be used. In addition, the device inlet exhaust gas and the decomposition gas may be in the opposite direction or may be in parallel. In this embodiment, a double tube heat exchanger is used, and the inlet and outlet gases of the device are circulated in opposite directions.

The acid component removing device 232 is filled with a drug layer 232a made of a calcium salt, and the HF contained in the decomposition gas is dry-removed by the adsorption reaction with the calcium salt. As the calcium salt, CaCO ₃ (calcium carbonate), Ca(OH) ₂ (calcium hydroxide), CaO (calcium oxide), or the like can be used. Further, the shape of the calcium salt may be in the form of a powder, but it is preferably a pellet formed into a cylindrical shape or a spherical shape in view of ease of handling. In the present embodiment, for example, a mixture of Ca(OH) ₂ and CaCO ₃ is used, and CaCO ₃ : Ca(OH) ₂ = 50% by weight to 80% by weight: 20% by weight to 50% by weight. In this case, the moldability is good, and it is possible to suppress the occurrence of pulverization when the pellets are formed. Further, in the present embodiment, the mixture is used as a cylindrical pellet having a diameter of about 3 mm on the bottom surface and a height of about 8 mm.

In the adsorption reaction at this time, a case where CaCO ₃ or Ca(OH) ₂ is used as the calcium salt is taken as an example, and the reaction formula is as follows.

CaCO ₃ +2HF → CaF ₂ +CO ₂ +H ₂ O...(5)

Ca(OH) ₂ +2HF → CaF ₂ +2H ₂ O...(6)

It is understood from the above formulas (5) to (6) that HF reacts with a calcium salt to produce CaF ₂ (calcium fluoride (fluorite)), CO ₂ (carbon dioxide), and H ₂ O (water).

The ejector 233 is connected to a compressed air pipe through which compressed air flows, and the exhaust gas is sucked by the negative pressure generated by the compressed air at a high speed, and discharged to the perfluorate together with the compressed air. Outside the device 2. Thereby, the exhaust gas is further lowered in temperature and discharged. The exhaust gas discharged from the acid component removing device 232 is, for example, about 200 ° C, and the exhaust gas discharged from the ejector 233 is, for example, 100 ° C or lower.

Further, the decomposition gas is introduced from below the acid component removing device 232 and is discharged from above the acid component removing device 232. Then, during the period in which the decomposition gas flows upward from the lower side of the acid component removing device 232, the reaction of HF and the calcium salt exemplified in the above formula (3) is caused, and the HF is dry-removed. At this time, since the calcium salt becomes CaF ₂ and no further reaction is carried out, it is necessary to exchange them in order.

Therefore, in the present embodiment, the medicine supply device 234 that supplies the calcium salt to the acid component removing device 232 and the drug discharge device 235 that discharges the used calcium salt from the acid component removing device 232 are provided.

In the present embodiment, the concentration of HF is monitored by the HF concentration sensor 236, and when the concentration of HF reaches 100 ppm, for example, the exchange period of the calcium salt is judged. Next, opening and closing of a rotary valve (not shown) or the like provided in the medicine discharge device 235 is performed to discharge a specific amount of the used calcium salt. In addition, after the calcium salt to be used is discharged, a rotary valve (not shown) or the like provided in the drug supply device 234 is opened and closed to supply a discharged amount of a new calcium salt. In this manner, the calcium salts in the drug discharge device 235 are sequentially exchanged. Further, in this series of steps, the control unit 24 acquires information on the concentration of HF sent from the HF concentration sensor 236, and when the concentration of HF reaches 100 ppm, for example, it is provided in the medicine supply device 234 or the medicine discharge device. The control of the opening and closing of the rotary valve of 235 is automatically performed. In addition, the calcium salts can also be exchanged at this time, usually only a part of them are exchanged. The amount of calcium salt exchanged is, for example, 40 kg/h.

The powder separator 237 is provided for removing the powder of the calcium salt generated in the acid component removing device 232 during the exchange of the calcium salt. As the powder separator 237, a metal mesh filter or the like can be used.

In the present embodiment, the powder separator 237 can be treated as an exhaust gas after the solid component is removed by the acid component removing device 232 to remove the solid component.

<Description of Operation of Fluoride Treatment Device>

Fig. 5 is a flow chart showing the operation of the perfluorochemical treatment device 2.

Hereinafter, the operation of the perfluorinated material processing apparatus 2 will be described with reference to FIGS. 3 and 5.

First, the device inlet exhaust gas is preheated by the inlet heater 211 of the pretreatment unit 21 (step 101). Thereby, the mist particles contained in the exhaust gas of the device inlet are evaporated.

Next, the pre-heated device inlet vent gas is introduced into the air, and the particles are removed by the filter 212 of the pretreatment unit 21 (step 102).

Next, the device inlet exhaust gas is heated by heat exchange according to the heat exchanger 231 (step 103). Further, at this time, water necessary for the decomposition reaction of the perfluorinated product is added (step 104).

The gas is exhausted through the device inlet of the heat exchanger 231, and is heated by the first heater 221 (step 105), and further heated by the second heater 222 to a temperature necessary for decomposition of the perfluorate (step 106). . Next, when passing through the catalyst layer 222b of the second heater 222, the perfluorinated material is decomposed, and the gas is discharged from the apparatus inlet to become a decomposition gas containing HF (step 107).

The gas is decomposed and re-enters the heat exchanger 231 for heat exchange with the inlet gas of the apparatus described above (step 108).

Next, the gas is decomposed, and the acid component removing device 232 reacts with the calcium salt, and the HF is dry-removed (step 109). Further, at this time, the control unit 24 determines whether or not the HF concentration acquired by the HF concentration sensor 236 is equal to or greater than a specific value (step 110). Then, become a specific value When the above (step 110, Yes), the medicine discharge device 235 and the medicine supply device 234 are operated to exchange calcium salts (step 111). Further, when the specific value is not reached (No in Step 110), the exchange of the calcium salt is not performed, and the process proceeds to the next step 112.

The exhaust gas after the HF is dry-removed is removed by a powder separator 237 (step 112), and is removed to the superfluorinated processing apparatus 2 by an ejector 233 (step 113).

The perfluorochemical treatment device 2 detailed above has the features as described below.

(i) Decomposition of perfluoride by the catalyst layer 222b allows a large amount of etching exhaust gas to be processed while reducing the running cost.

(ii) The HF contained in the decomposition gas is dry-removed by the adsorption reaction with the calcium salt, and the HF-containing discharge water is not generated in the method of removing HF by dissolving HF in water. Further, CaF ₂ produced after the adsorption reaction is harmless and is easy to handle. Further, CaF ₂ is a valuable raw material for producing HF. In summary, valuable CaF ₂ can be produced from etched exhaust gases that are harmful to the global environment.

(iii) The heat exchange between the exhaust gas and the decomposition gas at the inlet of the device by the heat exchanger 231 improves the utilization efficiency of the energy. In addition, there is no discharge water as compared with the previous method of cooling the decomposition gas by water. Therefore, the drainage treatment step is not required, and the operation cost of the perfluorinated treatment apparatus 2 can be reduced.

(iv) being disposed above the acid component removing device 232 by grouping The drug supply device 234 and the drug layer 232a having the drug discharge device 235 at the lower side can exchange calcium salts by a simple system in which only the valve is opened by gravity. Further, in the present embodiment, the decomposition gas is introduced from below, and exhausted from above, and the HF concentration sensor 236 is provided to monitor the concentration of HF to determine the exchange period of the calcium salt. Thereby, the upper layer portion of the drug layer 232a is not discharged, and only the already reacted calcium salt in the lower layer portion is discharged, so that unreacted calcium salt is hardly generated, and the unnecessary consumption of the calcium salt can be reduced.

<Explanation of actual fluoride processing device>

Fig. 6 is a view showing the actually manufactured perfluorinated treatment device 2 as seen from above. Further, Fig. 7 is a view showing the actually manufactured perfluorinated material processing apparatus 2 as seen from the direction VII of Fig. 6. That is, Fig. 7 is a view of the processing device 2 in which the fluoride is viewed in the horizontal direction.

As shown in the figure, in the case of the actual perfluorochemical treatment device 2, almost all of the devices are disposed inside the rectangular region when viewed from the top or in the horizontal direction. Further, the control unit 24 is disposed outside the rectangular area. Further, the rectangular shape of the present embodiment has a rectangular shape as a basic shape, and a trapezoidal shape, a parallelogram shape, an elliptical shape, or the like which is close to a rectangular shape may be included in the rectangular shape within a range that does not escape the features of the present embodiment.

Next, each machine of the perfluorinated material processing apparatus 2 of Figs. 6 and 7 will be described. Further, in the following, the position at which the control unit 24 is placed as viewed from above will be described on the lower left side of the treatment device for perfluorinated material 2.

The device inlet exhaust gas is introduced from the lower left side of the perfluorinated treatment device 2. Next, it flows through the plural piping to the right direction in the figure, and passes through the inlet heater 211 provided in the lower side of the processing apparatus of the perfluoride. Next, at this time, preheating is performed by the heater 211a (refer to FIG. 3) disposed in the inlet heater 211. Thereby, the mist particles contained in the exhaust gas of the device inlet are evaporated. Further, the gas is exhausted through the inlet of the apparatus of the inlet heater 211, and then flows to the right in the drawing, and is introduced into the filter 212, and the fine particles contained in the discharge gas of the apparatus inlet are removed. Further, although not shown, air is introduced into the exhaust gas of the apparatus inlet after the inlet heater 211.

Further, in the present embodiment, the filter includes not only the filter 212 but also the preliminary filter 212a. In other words, when it is necessary to exchange the filter 212, the valve or the like provided in the pipe connected to the filter 212 is operated to switch the pipe through which the exhaust gas flows, so that the device inlet exhaust gas flows into the pre-filter. 212a. Thereby, the microparticles can be removed by the preliminary filter 212a during the exchange operation of the filter 212, and the exchange of the filter 212 can be performed without stopping the operation of the perfluorinated processing apparatus 2.

The gas is exhausted through the inlet of the apparatus after the filter 212, and flows through the pipe P1 in the direction of the arrow A to enter the heat exchanger 231 provided on the upper side of the treatment device for perfluorinated material. Next, the device inlet exhaust gas is heated by heat exchange according to the heat exchanger 231. Further, although not shown, water is added to the heat exchanger 231 at this time, and the water is transported together with the device inlet exhaust gas.

The gas discharged from the apparatus inlet discharged from the heat exchanger 231 flows into the direction of the arrow B through the pipe P2, and enters the first heater 221 provided on the lower right side of the processing device 2 for perfluorinated matter. The first heater 221 is a horizontal heater, and the gas is discharged from the inlet of the left inflow port in the figure, and the gas is exhausted from the inlet of the right discharge device in the drawing. Next, the first heater 221 is internally provided with a heater 221a (see FIG. 3), and the device inlet exhaust gas is heated while moving inside the first heater 221 from the left side to the right side.

Then, the gas discharged from the apparatus outlet discharged from the first heater 221 flows through the pipe P3 in the direction of the arrow C, and enters the second heater 222 provided on the upper right side of the processing device for the perfluorinated material. The second heater 222 is a vertical heater, and a heater 222a (see FIG. 3) is disposed above, and a catalyst layer 222b (see FIG. 3) is disposed below. Next, the device inlet exhaust gas flows in from above the second heater 222, and is continuously heated to the decomposition temperature of the perfluorate by the heater 222a, and flows into the lower side of the second heater 222. Next, the catalyst layer 222b, the perfluorinated product, and the water (water vapor) mixed with the device inlet exhaust gas are reacted to be decomposed. Next, an acidic decomposition gas containing HF of the decomposed product is discharged from the lower side of the second heater 222.

Then, the decomposition gas discharged from the second heater 222 flows through the pipe P4 in the direction of the arrow D, and enters the heat exchanger 231 again. Next, in the heat exchanger 231, heat exchange is performed between the high-temperature decomposition gas and the low-temperature device inlet exhaust gas.

The decomposition gas discharged from the heat exchanger 231, by piping P5 flows in the direction of the arrow E (the left direction in the drawing), and enters the acid component removing device 232 provided on the upper side of the treatment device for perfluorinated material 2. At this time, the decomposition gas flows into the lower side of the acid component removing device 232 and flows to the upper side of the acid component removing device 232. Next, at this time, the drug layer 232a (see FIG. 3) composed of a calcium salt is subjected to an adsorption reaction of HF contained in the decomposition gas, and is dry-removed. Then, the exhaust gas which is detoxified is discharged from the upper side of the acid component removing device 232.

The exhaust gas discharged from the acid component removing device 232 flows through the pipe P6 in the direction of the arrow F (the left direction in the drawing), and enters the powder separator 237 provided on the upper left side of the processing device for the perfluorinated material. Next, the powder of the calcium salt or the like is removed by a powder separator 237. Further, an HF concentration sensor 236 is disposed in the middle of the pipe P6, and the concentration of HF contained in the exhaust gas is measured. Further, the pipe P6 has a relatively long size in this embodiment, and has fins around it. In other words, it may be connected to the acid component removing device 232, and the pipe P6 toward the ejector 233 may be disposed along the other long side of the rectangular region, and may be provided with a heat radiating fin for cooling the exhaust gas. sheet. Thereby, the temperature of the exhaust gas can be further lowered.

Then, the exhaust gas discharged from the powder separator 237 is finally sucked by the ejector 233 provided on the upper left side of the treatment device for perfluorinated material, and flows through the pipe P7 toward the arrow G direction. (Upper direction in the figure), discharge to the outside of the unit.

The arrangement of each machine detailed above constitutes the inlet heater 211 of the pretreatment unit 21, the filter 212, and the first heater. 221 is arranged inside the rectangular area as viewed from above and sequentially along one of the long sides of the rectangular area.

In short, in the example shown in Fig. 6, the inlet heater 211, the filter 212, and the first heater 221 are disposed inside the rectangular region while the long side of the lower side of the rectangular region is from the left side to the right side. Ordering.

Further, the second heater 222, the acid component removing device 232, and the powder separator 237 are inside the rectangular region as viewed from above, along the other long side of the rectangular region, and the inlet heater 211. The filters 212 and the first heaters 221 are arranged in the reverse order of the order.

In short, in the example shown in FIG. 6, the second heater 222, the acid component removing device 232, and the powder separator 237 follow the inlet side heater 211 and the filter along the long side of the upper side of the rectangular region. 212. The order in which the first heaters 221 are arranged in the reverse order is sequentially arranged from the right side to the left side.

Further, the heat exchanger 231 is disposed on the other long side of the rectangular region and between the second heater 222 and the acid component removing device 232. In other words, in the example shown in FIG. 6, the long side of the upper side of one of the second heaters 222 or the acid component removing device 232 is arranged. However, not limited thereto, the inlet heater 211 may be arranged along the long side of the lower side of the filter 212 and the first heater 221.

By arranging the respective machines along the long side of the rectangular region as described above, the respective machines are arranged in an approximately U shape as indicated by the direction of the arrow H in accordance with the order in which the gas flows. Therefore, for example, the length occupied by the processing device 2 for perfluorinated material is changed from the top as compared with the case where the respective devices are arranged in a straight line. The small area is also small. Therefore, the entire apparatus can be made compact, for example, in a size that can be accommodated in a container or the like. Further, the apparatus for treating perfluorinated material 2 of the present embodiment can be made to be transported in a size suitable for storage in a 20-inch container.

Further, by arranging the respective machines along the long side of the rectangular region as described above, it is possible to form a passage in the central portion sandwiched between the two long sides. In Fig. 6, the operator can move by this path so that the arrow 2 is displayed. Further, the pipes P1, P2, and P3 are disposed on the head of the worker, and the worker can move to the passage without being hindered by the pipes P1, P2, and P3. By doing so, at the time of operation or maintenance of each machine, not only the outer side of the rectangular region but also the inner side can be operated by the passage, and the workability is improved.

Further, in the arrangement of the respective devices described above, the device inlet exhaust gas is introduced from the long side of one of the rectangular regions and at a position adjacent to the pretreatment unit 21, and the exhaust gas is discharged from the other long side of the rectangular region. And discharged at a position adjacent to the powder separator 237. Further, the heat exchanger 231 is mixed, and water or machine-type driving air (compressed air) necessary for discharging the gas at the inlet of the decomposition device is supplied from a position along one short side of the rectangular region.

In the case of such a configuration, the introduction of the discharge gas of the apparatus inlet and the discharge of the exhaust gas, and the supply of the water, and the apparatus including the compressed air used in the ejector 233, can be concentrated in one of the rectangular areas. On the side, the perfluorochemical treatment device 2 can be further easily miniaturized. Next, the first heater 221 or the second heater at a high temperature Since the 222 is disposed on the other short side of the rectangular region, it is possible to suppress the influence of the heat emitted by the first heater 221 or the second heater 222 on the device, its instrument, or the adjustment work space.

Further, according to the method for treating a perfluorinated product of the perfluorinated material processing apparatus 2 described above, it can be considered that the pretreatment step includes the step of removing the solid component and/or the mist particles by the device inlet exhaust gas, and the heating device inlet. a first heating step of discharging the gas and the water, and further heating the inlet gas and water heated by the apparatus heated by the first heating step, and simultaneously decomposing the perfluorinated product by a predetermined catalyst to generate a decomposition gas containing an acid gas. 2 heating step, in the latter stage of the first heating step and the second stage of the second heating step, the gas mixture mixed with the gas at the inlet of the device before the first heating step is simultaneously discharged with the decomposition gas after flowing out from the second heating step Heat exchange step of heat exchange, acid component removal step of dry removal of acid component by decomposition gas after flowing out from the heat exchange step, post treatment of removal of solid component by exhaust gas after dry removal of acid component by acid component removal step a step, a pre-processing step, and a first heating step, which are viewed from above in a rectangular region and along a rectangular region The position on the long side of the square is sequentially performed, and the second heating step, the acid component removing step, and the post-treatment step are viewed from above in the inside of the rectangular region and along the other long side of the rectangular region, before and after the execution. The method of treating the perfluorinated material is performed at the position opposite to the order of the processing step and the first heating step, respectively.

Further, in the above-described example, the case where the perfluorinated substance contained in the discharged etching exhaust gas is processed in a semiconductor manufacturing factory has been described, but it is of course not limited thereto. For example, it can also be processed by a liquid crystal maker Where the factory discharges effluent gas or cleans the perfluorate contained in the exhaust gas.

2‧‧‧Perfluoride treatment unit

24‧‧‧Control unit

211‧‧‧Inlet heater

212‧‧‧Filter

221‧‧‧1st heater

222‧‧‧2nd heater

231‧‧‧ heat exchanger

232‧‧‧acid component removal device

233‧‧‧ejector

236‧‧‧HF concentration sensor

237‧‧‧Powder separator (trap)

P1, P2, P3, P4, P5, P6, P7‧‧‧ piping

Claims (6)

A device for treating a perfluorinated product, comprising: a pretreatment means for removing solid components and/or mist particles from a gas containing perfluorinated materials; a first heating means for heating a gas containing perfluorinated matter and water, and further heating a second heating means for generating a decomposition gas containing an acid gas by hydrolyzing a perfluorinated product by a predetermined catalyst by a pre-fluorination-containing gas and water, which are heated by the first heating means, is disposed in the first 1 a front stage of the heating means and a rear stage of the second heating means, wherein the perfluorinated gas-mixed water before flowing into the first heating means is simultaneously heated with the decomposition gas after flowing out of the second heating means The heat exchange means exchanged, the acid component removing means for dry-removing the acid component by the decomposition gas flowing out from the heat exchange means, and the exhaust gas after the acid component is dry-removed by the acid component removing means to remove the solid component a post-processing means; the pre-processing means and the first heating means are viewed from above in a rectangular region and along the moment The long side of one of the regions is arranged in order, and the second heating means, the acid component removing means, and the post-processing means are viewed from above in the rectangular region and along the other long side of the rectangular region. The side is arranged in the order opposite to the order in which the pretreatment means and the first heating means are arranged. For example, the processing device for perfluorinated materials in the first application of the patent scope, The heat exchange means is disposed on the other long side of the rectangular region and disposed between the second heating means and the acid component removing means. The apparatus for treating a perfluorinated material according to the first or second aspect of the invention, wherein the piping connected to the post-treatment means by the acid component removing means is disposed along the other long side of the rectangular region , there are cooling fins for cooling exhaust gas. The apparatus for treating a perfluorinated material according to any one of claims 1 to 3, further comprising: a drug supply means for supplying a drug for dry removal of an acid component from above the acid component removing means, and The chemical agent discharge means for discharging the drug under the acid component removing means, and the decomposition gas introduced into the acid component removing means is introduced from the lower side of the acid component removing means, and is discharged from the upper side of the acid component removing means. The apparatus for processing a perfluorinated material according to any one of claims 1 to 4, wherein the water and/or machine-driven air mixed by the heat exchange means is short along one of the rectangular regions. The side position is supplied, and the second heating means is disposed on the other short side of the rectangular area. A method for treating perfluorinated materials, characterized by having: a pretreatment step of removing solid components and/or mist particles from a gas containing perfluoride, a first heating step of heating a gas containing perfluorinated material and water, and further heating a perfluorinated product heated by the first heating step a gas and water, a second heating step of decomposing the perfluorinated product by a predetermined catalyst to generate a decomposition gas containing an acid gas, a step before the first heating step, and a second step of the second heating step. a heat exchange step of performing heat exchange between the perfluorinated gas-containing mixed water before flowing into the first heating step and the decomposition gas after flowing out from the second heating step, and after flowing out from the heat exchange step An acid component removing step of decomposing the gas to remove the acid component, and a post-treatment step of removing the solid component by the exhaust gas after the acid component is dry-removed by the acid component removing step; the pre-treatment step and the first heating step, The position inside the rectangular region and along the long side of one of the rectangular regions is sequentially performed from the top, and the second addition is performed. The thermal step, the acid component removing step, and the post-treatment step are performed on the inside of the rectangular region and along the other long side of the rectangular region from the top, and performing the pretreatment step and the first heating The order of the steps is reversed in the order of the positions.