JP4249329B2 - Purification system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to ammonia or gas contained in an atmosphere controlled at a low dew point, such as a dry chamber, a clean booth, a clean chamber, and a stocker, used in the manufacture of semiconductor devices, liquid crystal displays, and magneto-optical disks, for example. Remove organic impuritiesCisSystem.
[0002]
[Prior art]
Nowadays, for example, in the manufacture of semiconductor elements, liquid crystal displays, magneto-optical disks, etc., dry gases (air, nitrogen, helium, argon, etc.) are used to control low dew points with little gaseous impurities. However, even in such a case, it is necessary to remove a trace amount of ammonia and gaseous organic impurities generated during the manufacturing process or generated from peripheral devices.
[0003]
In this regard, it has been used for supporting materials such as honeycomb structures and those filled with chemical adsorbing materials (activated carbon, zeolite, etc.) that have been used to remove basic and acidic gases in the atmosphere. It is possible to apply what was carried. It is also conceivable to use a chemical filter using ion exchange fibers.
[0004]
[Problems to be solved by the invention]
However, since adsorbent materials with chemicals are a technology that uses the molecular adsorption power of adsorbent materials and chemical reactions between the adsorbed chemicals, there are many reactions that are promoted through moisture, and the low dew point atmosphere as described above. When used in, the performance will be inferior. In addition, a chemical filter using ion exchange fibers is a technique that removes gaseous impurities using a chemical reaction via moisture, and therefore cannot perform in a low dew point atmosphere.
[0005]
  The present invention has been made in view of such points, and in order to remove trace amounts of ammonia and gaseous organic impurities contained in the dry gas, a hydrophilic zeolite that does not attach any chemicals to the surface of the support and Select an inorganic substance effective for adsorbing gaseous organic impurities, and purify the dry gas atmosphere as described above using a filter having an adsorption layer composed of bothCisIt is an object of the present invention to provide a system to solve the problem.
[0006]
[Means for Solving the Problems]
  For reference, the inventors' knowledgeA method for removing and purifying ammonia in a gas (dry gas) with a relative humidity of less than 10% and at least gaseous organic impurities or gaseous acidic impuritiesAsAn adsorption layer in which hydrophilic zeolite is fixed to the surface of a support using an inorganic substance having a property of adsorbing gaseous organic impurities and having an effective pore size larger than that of the zeolite as a binder. It is conceivable to use a gas purification filter having the same.
[0007]
Examples of the inorganic substance having the property of adsorbing gaseous organic impurities and gaseous acidic impurities and having an effective pore size larger than the effective pore size of the zeolite include diatomaceous earth, silica, alumina, silica and alumina. It is preferable to comprise at least one of a mixture of aluminum silicate, activated alumina, porous glass, hydrous magnesium silicate clay mineral having a ribbon-like structure, activated clay, and activated bentonite. The effective pore diameter of course depends on the effective pore diameter of the hydrophilic zeolite, but when the effective pore diameter of the hydrophilic zeolite is 8 angstroms, the effective pore diameter of these inorganic substances is about 15 to 300 angstroms or more. Is effective.
[0008]
In this way, the hydrophilic zeolite has the property of adsorbing gaseous organic impurities and gaseous acidic impurities, and an inorganic substance having an effective pore size larger than the effective pore size of the zeolite is used as the binder surface. By using a gas purification filter having an adsorbing layer fixed on the surface, ammonia and at least gaseous organic impurities or gaseous acidity do not cause chemical leakage, and also in a dry gas atmosphere having a relative humidity of less than 10%. High removal performance of impurities can be obtained. This will be described in more detail below.
[0009]
When hydrophilic zeolite is used as an adsorbent for ammonia and gaseous organic impurities or gaseous acidic impurities in a normal atmosphere (temperature: 25 ° C., relative humidity: 50%), the ammonia and gaseous organic impurities in the atmosphere However, since moisture is present in an overwhelmingly high concentration, the performance deteriorates before the removal target component is hardly adsorbed. FIG. 1 shows an adsorption isotherm of water measured in a 25 ° C. atmosphere for a hydrophilic synthetic zeolite having a pore diameter of 10 angstroms and a water-repellent synthetic zeolite having a pore diameter of 8 angstroms.
[0010]
In the case of hydrophilic synthetic zeolite, the amount of moisture adsorbed at a relative humidity of 100% is 0.306 cc / g, and even at a relative humidity of 10%, this moisture of nearly 85% is adsorbed. Ammonia and water are close in molecular diameter and polar, so they are easily adsorbed on the same part of the zeolite. Therefore, when the relative humidity is 10% or more, the zeolite adsorption sites are filled with moisture first, so that ammonia is not removed with high efficiency. Therefore, in order to remove air components other than moisture with high efficiency using hydrophilic zeolite, a low-humidity atmosphere with a low moisture concentration of less than 10% relative humidity is suitable.
[0011]
The removal performance of gaseous organic impurities and gaseous acidic impurities depends on the pore diameter and pore volume (see JP-A-11-76719). Further, since ammonia is a polar molecule, a highly polar adsorbent, that is, an adsorbent with a small Si / Al ratio and easy to adsorb moisture, exhibits higher removal performance. According to the knowledge of the inventors, the hydrophilic zeolite preferably has a Si / Al ratio of 2 or more and 10 or less. From the above, hydrophilic zeolite can remove ammonia without adding any chemicals. In use, the gas purification filter may be installed in the airflow in the same manner as a normal filter of this type.
[0012]
  AnnAfter the monia and at least gaseous organic impurities or gaseous acidic impurities are adsorbed to the adsorption layer, the adsorbed layer is depressurized to desorb the adsorbed ammonia, gaseous organic impurities and gaseous acidic impurities. And the ability of the filter can be restored. As the degree of decompression, a degree of decompression of 1 Torr or less is effective.
[0013]
  FurthermoreIf high-purity gas is supplied to the adsorption layer, the desorbed ammonia and gaseous organic impurities and gaseous acidic impurities can be purged, and the desorbed ammonia and gaseous organic impurities and gaseous impurities can be purged. Re-adsorption of acidic impurities to the adsorption layer can be prevented. As the high purity gas, for example, an inert gas such as nitrogen gas or helium gas can be proposed in addition to dry air described later.
[0014]
  In such a case,The effective pore size of hydrophilic zeolite is 3 angstroms to 8 angstroms, and its specific surface area is 100 m.²/ G or more is preferable.
[0015]
  As a system for suitably carrying out the dry gas purification method as described above,According to the present invention:A purification system can be provided. This purification system is used in a target space where there are objects to prevent pollution (for example, various products such as semiconductor elements and equipment such as semiconductor manufacturing equipment).Supply sectionAn inert gas supply device for supplying an inert gas (for example, nitrogen gas, helium gas, argon gas, etc.) fromThe supply unitThe first anti-contamination target set downstream of the anti-contamination target is positioned in the air stream of the inert gas supplied fromAn exhaust part;The second exhaust part set on the upstream side of the contamination prevention target in the air stream and the hydrophilic zeolite have a property of adsorbing gaseous organic impurities and have an effective pore size larger than the effective pore size of the zeolite. A gas purification filter having an adsorption layer fixed to the surface of the support using an inorganic material having a binder, and the gas purification filterSupply sectionAnd the target space is configured to be freely depressurized by exhaust from the second exhaust part, andThe supply section,Each of the first exhaust part and the second exhaust part is openable and closable.
[0016]
  According to the purification system having such a configuration, first, in the steady operation, the target spaceSupply sectionThe exhaust gas is exhausted from the first exhaust part while supplying the inert gas from the exhaust gas. As a result, an inert gas stream is formed in the target space, and impurities generated from the target object are exhausted as they are from the first exhaust section downstream.At this time the secondThe exhaust part is closed. And it has the adsorption layer which fixed the hydrophilic zeolite to the surface of the support body using the inorganic substance which has the property which adsorbs gaseous organic impurities and has an effective pore size larger than the effective pore size of the zeolite as a binder A gas purification filter in the airflowSupply sectionSince the inert gas contains ammonia, gaseous organic impurities and gaseous acidic impurities, these are gases. It is removed by a purification filter. Note that the steady operation is performed under a certain low pressure (for example, about 200 Torr) because the impurities are more likely to vaporize and are less likely to adhere, so that the contamination prevention effect is high.
[0017]
  And, for example, when the adsorption removal capacity of the gas purification filter is reduced,Supply sectionThe first exhaust part is closed, the atmosphere in the target space is exhausted from the second exhaust part, and the pressure in the target space is reduced. As a result, ammonia adsorbed on the adsorption layer of the gas purification filter, gaseous organic impurities, and gaseous acidic impurities are desorbed, and the adsorption removal capability of the filter is restored. The desorbed ammonia, gaseous organic impurities, and gaseous acidic impurities are exhausted from the second exhaust part. Since the second exhaust part is set on the upstream side of the air flow, the second exhaust part is located downstream of the contamination prevention target object during the decompression exhaust. Therefore, the contamination prevention target object is not contaminated by the desorbed ammonia and the gaseous organic impurities or gaseous acidic impurities.
[0018]
    The above-described system further includes a purge gas supply device that supplies purge gas into the target space from another supply unit that is set on the downstream side of the contamination prevention target in the airflow, and the other supply unit is openable and closable. If so, the following effects can be obtained.
  IeNext time,otherBy opening the supply unit and supplying purge gas into the target space, the atmosphere in the target space until then is purged, for example, impurities, ammonia, gaseous organic impurities and gaseous acids that could not be discharged by reduced pressure exhaust. Impurities are also purged. Therefore, the adsorption removal capability of the gas purification filter can be recovered more effectively. Thereafter, the steady operation may be started again. Of course, the decompression operation as described above may be performed again as necessary. By doing so, purge gas itselfDischargeCan be made.
[0019]
  In the configuration of the purification system,Supply sectionAnd the second exhaust,otherThe supply unit and the first exhaust unit may be shared, and the supply system and the exhaust system may be separated as separate systems outside the target space.
[0020]
  In the configuration of the purification system,Supply section,otherThe supply unit, the first exhaust unit, and the second exhaust unit are openable and closable, for example, by setting supply ports and exhaust ports corresponding to the supply unit and the exhaust unit, respectively. It is a concept that includes not only a configuration that can be directly opened and closed, but also a configuration that can open and close a valve of a piping system that communicates with the supply port and the exhaust port while the supply port and the exhaust port are always open. In short, the state for supplying from the supply unit or exhausting from the exhaust unit is “open”, and the state for stopping supply or stopping exhaust is “closed”.
[0021]
  As purge gas,For exampleCan propose dry air. In this case, dry air having a relative humidity of less than 10% is suitable. Furthermore thisIf the aboveA return air part is set upstream of the gas purification filter in the air flow (the air flow caused by the inert gas during steady operation), and the atmosphere in the target space taken from the return air part is supplied to the purge gas supply device. It may be configured. That is, in the purge operation, if a part of the exhausted air is used as return air, mixed with other raw material air (for example, outside air), and dried in the purge gas supply device, it is possible to save the generation of dry air. Energy can be realized.
[0022]
  In additionIf the exhaust path from the second exhaust section is branched outside the target space and can be switched to each path, the exhaust path during the decompression operation and the exhaust path during the purge operation can be switched. . Therefore, it is possible to make the capacities of the pumps and the like to be used suitable for each.
[0023]
  AndA particle removal filter, for example, a high-performance filter such as a HEPA filter or a ULPA filter, is arranged downstream of the gas purification filter in the air flow (air flow caused by inert gas during steady operation) and upstream of the contamination prevention target. Then, other fine impurities can be removed.
[0024]
In addition, the effective pore diameter of the hydrophilic zeolite used in the purification system according to each configuration as described above is 3 angstroms to 8 angstroms, and the specific surface area is 100 m.²/ G or more is preferable.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the purification system of the present invention will be described. FIG. 2 shows an exploded view of the gas purification filter 11 used in the present embodiment. As shown in the figure, the filter portion of the gas purification filter 11 is constituted by a honeycomb structure 14 serving as a support having a structure in which a thin sheet sheet 13 having no irregularities is sandwiched between a plurality of adjacent corrugated sheets 12. . The entire surface of the honeycomb structure 14 is provided with an adsorption layer having a configuration in which a powdery hydrophilic synthetic zeolite is fixed as an inorganic substance having an effective pore size larger than the effective pore size of the zeolite. ing.
[0026]
As shown in FIG. 2, the gas purification filter 11 has rectangular outer cylinders 21, 22, 23, and 24 that are opened in the flow direction of processing air (the direction indicated by white arrows in FIG. 2). And the honeycomb structure 14 is arranged in the internal space. The external shape and dimensions of the gas purification filter 11 can be arbitrarily changed according to the installation space. Further, depending on the necessity of supporting the honeycomb structure 14, the end portions of the aluminum outer frames 21, 22, 23, 24 may be appropriately bent into an angle.
[0027]
FIG. 3 shows an enlarged cross section of the honeycomb structure 14, and the honeycomb structure 14 can be manufactured, for example, as follows. For example, an inorganic fiber such as ceramic fiber, an organic material such as pulp, and calcium silicate are blended in equal weights, and are formed into a thickness of about 0.3 mm by a wet papermaking method to form a papermaking sheet. Thereafter, the paper sheet is corrugated by a corrugator, and the thin sheet 13 formed in the same manner as the other is bonded with an adhesive. Thereafter, when an organic component is removed by heat treatment in an electric furnace or the like, countless micron-sized recessed holes are formed on the surface of the honeycomb structure 14. Next, after dipping in a suspension in which a hydrophilic zeolite and an inorganic binder are dispersed for a predetermined time and pulling up, heat treatment is performed at a predetermined temperature, so that the adsorption layer is fixed to the surface of the honeycomb structure 14 as shown in FIG. You can get something.
[0028]
The cross section of the adsorbing layer 15 is as shown in FIG. 4 and has a structure in which an inorganic binder 17 is inserted into the gap between the hydrophilic zeolites 16. 18 is formed.
[0029]
FIG. 5 shows an outline of the purification system 31, and the target space in the present embodiment is a space S in the chamber 32 where KrF excimer laser exposure is performed. In the chamber 32, a contamination prevention object 34 such as a semiconductor manufacturing apparatus, an electronic component or a precision component is installed on a breathable floor panel 33 formed by grating or the like. A floor space D is formed by the floor panel 33.
[0030]
Above the contamination prevention object 34, a ULPA filter 35 is disposed as a high-performance filter, and above the ULPA filter 35, the gas purification filter 11 is disposed. A ceiling space U is formed above the gas purification filter 11.
[0031]
The chamber 32 is provided with a first supply unit 41 that opens into the ceiling space U, and the first supply unit 41 communicates with an inert gas supply device 42 via a valve V1. A first exhaust part 43 is provided in the chamber 32 so as to open to the underfloor space D, and the first exhaust part 43 communicates with the suction pump P1 via the valve V2.
[0032]
Further, the chamber 32 is provided with a second supply unit 51 that opens into the underfloor space D, and the second supply unit 51 communicates with a dry air supply device 52 as a purge gas supply device via a valve V3. Yes. The dry air supply device 52 performs a dehumidification process or a purification process on the raw air (for example, the outside air) using, for example, a dry dehumidifier using a dry rotor, and low dew point air, for example, a dew point temperature. Has a function of supplying dry air of −10 ° C. or lower into the chamber 32. The raw material air is taken in through the introduction pipe 53, and the introduction pipe 53 is provided with a valve V4.
[0033]
In the present embodiment, a return air portion 54 is provided in the chamber 32 and opens to the ceiling space U. The return air portion 54 is provided downstream of the valve V4 in the introduction pipe 53 via the valve V5. Communicates.
[0034]
The chamber 32 is further provided with a second exhaust part 61 that opens into the ceiling space U. This second exhaust part 61 branches outside the chamber 32, one leading to the vacuum pump P2 for pressure reduction via the valve V6, and the other leading to the exhaust pump P3 via the valve V7. .
[0035]
Each of the above-described valves V1 to V7 is configured to be opened and closed independently. Of course, it may be configured to automatically control the opening and closing according to each operation mode described later, that is, at the time of depressurization and purging of the steady operation and the regeneration operation.
[0036]
The purification system 31 according to the present embodiment is configured as described above. Next, an example of the operation will be described.
[0037]
(Steady operation)
In steady operation, only the valves V1 and V2 are open, and the other valves V3 to V7 are all closed. Then, an inert gas having a high purity and a low dew point (temperature: 23 ° C., dew point temperature: −20 ° C. or lower) is supplied from the first supply unit 41 into the chamber 32 from the inert gas supply device 42, and the pump When P 1 is activated, the inert gas flows down into the space S in the chamber as a down flow and is exhausted from the first exhaust part 43. At this time, the pressure in the chamber 32 is set to be 200 Torr. In this way, operating the apparatus in a certain degree of reduced pressure (low pressure) is more effective in preventing contamination because impurities are more easily vaporized and less likely to adhere.
[0038]
Since the inert gas is passed through the gas purification filter 11, ammonia, gaseous organic substances and gaseous acidic impurities contained in the inert gas are removed, and fine dust and the like are also removed by the ULPA filter. Since it is removed, an extremely clean inert gas is supplied to the contamination prevention target 34.
[0039]
The inert gas containing impurity gas (ammonia and gaseous organic matter or gaseous acidic impurities) generated from the pollution prevention target 34 itself is exhausted from the first exhaust part 43 to the outside of the chamber 32, For example, post-processing is performed by a gas scrubber (not shown). In this case, a part of the inert gas exhausted from the second exhaust part 43 may be returned to the upstream side of the gas purification filter 11 and circulated in the chamber 32 for operation.
[0040]
(Regeneration operation)
Then, after the operation for a long time, when the removing ability of the gas purification filter 11 is lowered, the regeneration operation is started. As shown in FIG. 6, the valves V1 and V2 are closed, only the valve V6 is opened, and the vacuum pump P2 is operated to perform evacuation. In this case, for example, vacuuming is performed until the pressure in the chamber 32 becomes 0.2 Torr or less. As a result, ammonia and gaseous organic substances adsorbed around the pores in the adsorption layer of the gas purification filter 11 and at shallow portions of the pores are desorbed.
[0041]
At this time, the gas in the chamber 32 flows from the contamination prevention target 34 side in the opposite direction to that during the steady operation, such as ULPA filter 35 → gas purification filter 11 → second exhaust unit 61, and is discharged. The gas is processed by a gas scrubber (not shown) or the like.
[0042]
Next, a purge operation is started to remove ammonia adsorbed in the deep pores of the adsorption layer of the gas purification filter 11 and gaseous organic substances and gaseous acidic impurities using the concentration gradient. That is, as shown in FIG. 7, the valves V1, V2 and V6 are closed, and the other valves V3, V4, V5 and V7 are opened. Then, high-purity dry air is supplied from the dry air supply device 52 to the underfloor space D in the chamber 32 through the second supply unit 51 so that the inside of the chamber 32 becomes atmospheric pressure.
[0043]
At this time, the gas in the chamber 32 flows in the opposite direction from the ULPA filter 35, the gas purification filter 11 and the steady operation from the contamination prevention object 34 side. The gas exhausted from the second exhaust part 61 is exhausted from the exhaust pump P3 and processed by a gas scrubber (not shown) or the like.
[0044]
On the other hand, from the ceiling space U, a part of the gas in the chamber 32 is returned to the dry air supply device 52 through the return air unit 54, where after the moisture reduction process and the purification process are performed together with the raw air, the process is again performed. It is supplied to the underfloor space D in the chamber 32 through the second supply unit 51.
[0045]
In this way, after the purge operation is performed for a predetermined time, the decompression operation is performed again. That is, as shown in FIG. 8, the valve V1, the valve V2, the valve V3, the valve V4, the valve V5, and the valve V7 are closed, only the valve V6 is opened, and the vacuum pump P2 is operated to perform evacuation. As a result, the ammonia desorbed from the gas purification filter 11 remaining in the chamber 32 and the dry air containing gaseous organic substances and gaseous acidic impurities are discharged to the outside.
[0046]
When the regeneration operation mode is completed as described above, ammonia, gaseous organic matter, and gaseous acidic impurities in the adsorption layer of the gas purification filter 11 are removed, and the capacity is restored. Therefore, the performance of the gas purification filter 11 can be recovered without removing the gas purification filter 11 and cleaning or replacing it. Therefore, it is possible to immediately enter the steady operation mode as shown in FIG.
[0047]
In order to investigate the effect of the purification system 31 according to the embodiment, ammonia is mixed downstream of the inert gas supply device 42, and the ammonia concentration in the inert gas is adjusted to 4 vol ppm. The results of examining the ammonia removal performance by the filter 11 are shown in the graph of FIG. In the experiment, the regeneration operation was carried out every time a load corresponding to 10,000 hours was applied with 5 volppb of ammonia. In the graph of FIG. 9, the horizontal axis represents the actual load concentration (4 vol ppm) converted to the ammonia load time equivalent to 5 vol ppb (the time obtained by multiplying the actual load time by 800). The Si / Al ratio of the hydrophilic zeolite used was 3, and silica was used as the inorganic binder. Further, the thickness of the honeycomb structure 14 of the gas purification filter 11 is 50 mm. And the ventilation speed | velocity | rate of helium gas as an inert gas which passes the gas purification filter 11 is 0.9 m / s, the temperature of the said helium gas is 23 degreeC, and a dew point temperature is -20 degrees C or less.
[0048]
As can be seen from this result, according to the purification system 31, it was confirmed that ammonia could always be removed with a high efficiency of 80% or more and clean dry gas could be supplied.
[0049]
Similarly, the graph of FIG. 10 shows the change over time in the removal rate of sulfur dioxide, which is a gaseous acidic impurity. At this time, the accelerated load concentration of sulfur dioxide is 900 volppb, the converted load concentration is 0.3 vol ppb, and other conditions are the same as in the case of ammonia. Similarly, the graph of FIG. 11 shows the change over time in the removal rate of N-methylpyrodrin, which is a gaseous organic impurity. At this time, the accelerated load concentration of N-methylpyrodrin is 350 vol ppb, the converted load concentration is 3 vol ppb, and other conditions are the same as in the case of ammonia.
[0050]
As can be seen from the graphs of FIGS. 10 and 11, the above-described gaseous acidic impurities and gaseous organic impurities are also regenerated every predetermined time (for example, every 10,000 hours) as in the case of ammonia. By doing so, the removal rate can be maintained at 80% or more. Therefore, if the regeneration operation as described above is performed every predetermined time, the inside of the chamber 32 can be always maintained in a clean atmosphere from which ammonia, gaseous acidic impurities, and gaseous organic impurities are removed. is there.
[0051]
As described above, according to the purification system 31 according to the present embodiment, ammonia, gaseous organic impurities, and gaseous acidic impurities can be effectively removed even in a low dew point atmosphere. The removal ability of the gas purification filter 11 can be recovered without removing and cleaning the filter 11 or replacing it.
[0052]
In the embodiment, the first supply unit 41, the first exhaust unit 43, the second supply unit 51, and the second exhaust unit 61 are all set as independent parts. In view of the air flow direction in each operation, the first supply unit 41 and the second exhaust unit 61, and the second supply unit 51 and the first exhaust unit 43 on the opening side to each chamber 32 side (that is, supply) The configuration of the chamber 32 can be simplified if the configuration is combined into one by using both the port and the exhaust port. Also in the above embodiment, if the underfloor space D is separable by a shutter or the like, the underfloor space D is not used as a common flow path, and is used for high-purity gas circulation and exhaust of impurities-containing gas. It can be divided and more anti-pollution effect can be expected.
[0053]
In the above embodiment, the regeneration operation is possible by the decompression operation. Of course, if the purpose is only to remove ammonia and at least gaseous organic impurities or gaseous acidic impurities by the gas purification filter 11, FIG. The present invention can also be applied to a stocker (storage) 71 of the second embodiment. In the figure, members, devices, and the like indicated by the same reference numerals used in the description of the first embodiment indicate the same members, devices, and the like.
[0054]
In the stocker 71, a product 73 such as a semiconductor wafer is stored in the chamber 72 as a contamination prevention object. A supply unit 74 is set on the upstream side of the gas purification filter 11. The supply unit 74 communicates with the dry air supply device 52 through the valve V11. On the other hand, an exhaust part 75 is set below the chamber 72.
[0055]
Also in the stocker 71 having such a configuration, for example, ammonia and gaseous organic impurities can be suitably removed from the low dew point air supplied from the dry air supply device 52.
[0056]
Further, in the stocker 71, the air discharged from the exhaust unit 75 may be returned to the upstream side of the dry air supply device 52 and circulated. In this case, there is an advantage that the energy required for dehumidification can be reduced as compared with the case of processing normal raw material air. When the humidity control in the stocker 71 is not so strict, the air discharged from the exhaust unit 75 may be returned to the downstream side of the dry air supply device 52 and used.
[0058]
【The invention's effect】
  Claim 1According to the purification system, steady operation and decompression operation that is recovery operationThe,And according to the purification system of claim 2,The purge operation can be performed by switching between each supply unit and each exhaust unit. Therefore, the recovery operation of the gas purification filter can be automatically performed periodically.
[0059]
  Especially claims3As described above, if dry air is used as the purge gas, it is possible to reduce operating costs and the like.4Then, it can carry out under energy saving. And claims5If the exhaust path from the second exhaust section is branched and switched as described above, the capacity of a pump or the like used for exhaust can be made suitable for each. And claims6In this case, other fine impurities can be removed.
[Brief description of the drawings]
FIG. 1 is an adsorption isotherm of synthetic zeolite having different Si / Al ratios.
FIG. 2 is an exploded view of the gas purification filter used in the embodiment of the present invention.
3 is an enlarged cross-sectional view of a main part of the gas purification filter of FIG.
4 is an enlarged cross-sectional view of an adsorption layer of the gas purification filter of FIG.
FIG. 5 is an explanatory diagram of a purification system according to an embodiment of the present invention during steady operation.
FIG. 6 is an explanatory diagram of the purification system according to the embodiment of the present invention at the time of decompression in the regeneration operation.
FIG. 7 is an explanatory diagram of the purification system according to the embodiment of the present invention at the time of purging in the regeneration operation.
FIG. 8 is an explanatory diagram of the purification system according to the embodiment of the present invention at the time of decompression in the regeneration operation.
FIG. 9 is a graph showing a change with time of ammonia removal performance by the purification system according to the embodiment of the present invention;
FIG. 10 is a graph showing the change with time of the removal performance of sulfur dioxide by the purification system according to the embodiment of the present invention.
FIG. 11 is a graph showing a change with time of removal performance of N-methylpyrrolidone by the purification system according to the embodiment of the present invention.
FIG. 12 is an explanatory diagram of a stocker according to a second embodiment of the present invention.
[Explanation of symbols]
11 Gas purification filter
14 Honeycomb structure
31 Purification system
32 chambers
34 Pollution prevention target
35 ULPA filter
41 First supply section
42 Inert gas supply device
43 First exhaust part
51 Second supply section
52 Dry air supply device
54 Return Air
61 Second exhaust part
P1 suction pump
P2 vacuum pump
P3 exhaust pump
V1 ~ V7 valve

Claims (7)

An inert gas supply device for supplying an inert gas from a supply unit into a target space where a contamination prevention target exists;
A first exhaust unit set on the downstream side of the pollution prevention target so as to position the pollution prevention target in an air flow of an inert gas supplied from the supply unit;
A second exhaust part set on the upstream side of the contamination prevention object in the airflow;
It has an adsorbing layer in which hydrophilic zeolite is adsorbed to gaseous organic impurities, and an inorganic substance having an effective pore size larger than the effective pore size of the zeolite is used as a binder, and is fixed to the surface of the support. A gas purification filter,
The gas purification filter is disposed on the downstream side of the supply unit in the airflow and on the upstream side of the contamination prevention object,
The target space is configured to be depressurized by exhaust from the second exhaust part,
Further, the purification system, wherein the supply unit, the first exhaust unit, and the second exhaust unit are openable and closable. The apparatus further includes a purge gas supply device that supplies purge gas into the target space from another supply unit set on the downstream side of the contamination prevention target in the airflow, and the other supply unit is openable and closable. The purification system according to claim 1. The purification system according to claim 2, wherein the purge gas supplied from the purge gas supply device is dry air. The return air section is set on the upstream side of the gas purification filter in the air flow, and the atmosphere in the target space taken in from the return air section is supplied to the purge gas supply device. 3. The purification system according to 3. The purification system according to any one of claims 1 to 4, wherein an exhaust path from the second exhaust section branches out of the target space and can be switched to each exhaust path . The purification system according to any one of claims 1 to 5, wherein a particle removal filter is disposed on the downstream side of the gas purification filter in the air stream and on the upstream side of the contamination prevention target . 7. The purification system according to claim 1, wherein the effective pore diameter of the hydrophilic zeolite is 3 angstroms to 8 angstroms, and the specific surface area is 100 m ² / g or more .

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