JP2010095434A - Method and apparatus for purifying nitrogen gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such the problem that sodium chloride and water are used in order to enhance the reaction of oxygen gas and iron powder, however, when water remains by any possibility, in many cases, generated nitrogen gas can not be used. <P>SOLUTION: Nitrogen gas mixed with oxygen gas is made to pass through a nitrogen gas purifying apparatus 300, 400 storing cerium oxide 325 that absorbs the oxygen gas by reaction with the oxygen gas. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and apparatus for purifying nitrogen gas, and more specifically, cerium oxide that absorbs oxygen gas by reacting with oxygen gas from low-purity nitrogen gas mixed with oxygen gas. This describes the technology for producing high-purity nitrogen gas.

  Conventionally, the technology related to the purification method and apparatus for nitrogen gas is to produce high-purity nitrogen gas from iron gas mixed with oxygen gas by using iron powder that reacts with oxygen gas. There were some (see, for example, Patent Document 1).

In this case, it was very effective to use sodium chloride as a catalyst in addition to iron powder and to add water.
JP 2003-119209 A

  However, the conventional nitrogen gas production method and production apparatus have the following problems.

  In other words, sodium chloride or water is used to enhance the reaction between oxygen gas and iron powder, but if water remains, it is impossible to use the produced nitrogen gas. There were many.

  Therefore, if it is attempted to completely remove water, it is necessary to arrange a dryer or the like, but as a result, the entire apparatus tends to have a high unit price of nitrogen gas produced.

  The present invention is characterized by passing nitrogen gas mixed with oxygen gas through nitrogen gas purification apparatuses 300 and 400 containing cerium oxide 325 that absorbs oxygen gas by reacting with oxygen gas, and further, The nitrogen gas refining apparatuses 300 and 400 can be used independently or in front and rear on-off valves 290 so that the cerium oxide 325 can be replaced in response to the stored cerium oxide 325 being unable to absorb oxygen gas. , 410 can be attached and detached integrally, and further, the cerium oxide 325 reacts with oxygen gas to store oxygen gas in an unused state. The inlet and outlet of the nitrogen gas purifiers 300 and 400 are shut off from the atmosphere so that they do not react with oxygen in the atmosphere. The fact that the cerium oxide 325 can determine that the cerium oxide 325 can no longer react with oxygen by using the color change before and after the cerium oxide 325 reacts with oxygen. In addition, after determining that the cerium oxide 325 can no longer react with oxygen, it can be regenerated to a state where oxygen gas can be absorbed by injecting hydrogen gas. By solving the above-mentioned problems, the above problems have been solved.

  The present invention also includes a nitrogen tank 220 storing nitrogen gas containing oxygen gas as an impurity, and nitrogen gas containing powdered or tablet-like cerium oxide 325 that absorbs oxygen gas by reacting with oxygen gas. Further, the nitrogen gas purifiers 300 and 400 are configured to correspond to the fact that the cerium oxide 325 accommodated therein cannot absorb oxygen gas. The cerium 325 can be attached and detached independently so that the cerium 325 can be replaced. The cartridges 310 and 410 containing the cerium oxide 325 and the cartridges 310 and 410 are sealed when stored. The seal mechanism 330, 340, 430, 440 located on both the upper and lower sides Furthermore, the sealing mechanisms 330, 340, 430, and 440 are provided while the cerium oxide 325 stored in the cartridges 310 and 410 is stored in a state before use. In order to prevent reaction with oxygen in the atmosphere, both the inlets and outlets of the cartridges 310 and 410 can be cut off from the atmosphere, and the bottoms 331a and 341a or the bottoms 431a and 441a having the flanges and the small holes 331g are configured. 341g, 431g, 441g are formed, and the O-rings 332, 342, 433, 443 are stored by the bases 331a, 341a having the flanges or the bodies 331, 341, 431, 441 attached to the bottoms 431a, 441a. Sometimes both lower and upper lids 312 as inlets and outlets for the cartridges 310, 410 The bosses 312 a, 313 a, 412 a, 413 a formed integrally with 313, 412, 413 and the O-rings 332, 342, 433, 443 are brought into contact to seal the inside of the cartridge 310, 410, and when installed, the lid 312 Bosses 312a, 313a, 412a, 413a formed integrally with 313, 412, 413 and the O-rings 332, 342, 433, 443 are detached, and the small holes 331g, 341g, 431g, 441 g, and further, the cartridge 310, so that the cerium oxide 325 in a powdered or tableted state for some reason does not flow out downstream. 410 is a cross-section along the fluid flow and the lower and upper ends. The non-woven fabrics 323, 324, 423, 424 are positioned inside the two perforated plates 321, 322, 421, 422 on the lower side and the upper side so as to form spaces 311x, 311y, 411x, 411y, respectively. As a result, the spaces 311x, 411x, the perforated plates 321, 421, the nonwoven fabrics 323, 423, the cerium oxide 325, the nonwoven fabrics 324, 424, and the perforated plates 322, 422, along the flow of nitrogen gas The space portions 311y and 411y are positioned in this order, and further, a pre-filter 520 for removing foreign substances is installed downstream of the nitrogen gas purification devices 300 and 400. Further, the nitrogen gas purification devices 300 and 400 Attach a sticker showing the history to any place, and after installing the nitrogen gas purification devices 300, 400, the date of installation It is characterized in that the exchange is managed by simultaneously contacting and returning the seal. Furthermore, in order to confirm the color change before and after the cerium oxide 325 reacts with oxygen, the cartridge main bodies 311 and 411 are made transparent. Or provided with transparent holes 311f, 311g, 312g, 313g, 411f, 411g, 412g, 413g using a transparent material in the cartridge body 311 and 411 and the lids 312, 313, 412 and 413, The perforated plates 321, 322, 421, 422 are provided with peep holes 321 g, 322 g, 421 g, 422 g and the non-woven fabrics 323, 324, 423, 424 are provided with peep holes 323 g, 324 g, 423 g, 424 g, and the cerium oxide 325 is visible. By solving the above problems, A.

  As is clear from the above description, the present invention can provide the following effects.

  First, it consists of a nitrogen tank that stores nitrogen gas containing oxygen gas as an impurity, and a nitrogen gas purification device that contains powdered or tablet-like cerium oxide that reacts with oxygen gas to absorb oxygen gas As a result, a nitrogen gas refining device that does not generate water even when oxygen gas is absorbed by reacting with oxygen gas has become possible.

  Secondly, the nitrogen gas purification device is independent or integrated with front and rear on-off valves so that cerium oxide can be replaced in response to the stored cerium oxide being unable to absorb oxygen gas. By enabling attachment and removal, it became easy to replace deteriorated cerium oxide.

  Third, the inlet of the nitrogen gas refining device is used so that the cerium oxide does not react with oxygen in the atmosphere while it is stored in an unused state that can absorb oxygen gas by reacting with oxygen gas. By blocking the outlet from the atmosphere, the nitrogen gas purifier can be stored for a long period of time in an unused state.

  Fourth, by using the color change before and after cerium oxide reacts with oxygen, it is possible to judge that cerium oxide can no longer react with oxygen. It is now possible to easily determine the exact time for replacement according to the correct structure.

  Fifth, after determining that cerium oxide can no longer react with oxygen, it can be regenerated to a state where oxygen gas can be absorbed by injecting hydrogen gas. It can be used many times, and the unit price of high-purity nitrogen gas can be reduced.

  Sixth, the cross section along the fluid flow of the cartridge and the lower side so that the cerium oxide in a powdered or tableted state for some reason does not flow downstream. The lower and upper two perforated plates are positioned on the inner side so as to form a space between the upper end and the upper end, respectively. As a result, the space and the hole are formed along the flow of nitrogen gas. Concern that powdered cerium oxide will flow out by placing a pre-filter to remove foreign substances downstream of the nitrogen gas purifier, positioned in the order of perforated plate, non-woven fabric, cerium oxide, non-woven fabric, perforated plate and space Has been resolved.

  Seventh, stick the seal showing the history to any place of the nitrogen gas purification device, and after the nitrogen gas purification device is installed, manage the replacement by sending the date of installation and returning the seal at the same time Therefore, it has become possible to manage in an ideal manner including the period during which the nitrogen gas purifier can be stored.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Here, FIG. 1 is a diagram showing the whole of the present invention, FIG. 2 is a diagram showing a nitrogen gas purification apparatus of the present invention and devices before and after, and FIG. 3 is a nitrogen gas of the present invention. FIG. 4 is an upper detailed sectional view centering on the sealing mechanism when the purification apparatus is stored, and FIG. 4 is an upper detailed sectional view centering on the sealing mechanism when the nitrogen gas purification apparatus of the present invention is installed. 5 is a detailed cross-sectional view of the upper part centering on the seal mechanism when another nitrogen gas purification device of the present invention is stored, and FIG. 6 is a diagram when another nitrogen gas purification device of the present invention is installed. It is upper detail sectional drawing centering on a seal mechanism. In this case, the contents of FIGS. 3 to 5 show the detailed sectional view of the upper part while being vertically symmetric, but the characters in () mean the lower part code on the entrance side.

(First embodiment)
As shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4, 300 is a nitrogen gas purifier, which contains therein cerium oxide 325 that absorbs oxygen gas by reacting with oxygen gas. Yes. In addition, regarding cerium oxide 325, it is possible to use either a powdery or molded tablet.

  Incidentally, the nitrogen gas purification apparatus 300 is composed of a cartridge 310, a seal mechanism 330 positioned on the lower side which is the inlet thereof, and a seal mechanism 340 positioned on the upper side which is the outlet thereof. The cerium oxide 325 is housed in the front, and the front and back of the cerium oxide 325 are held by the nonwoven fabrics 323 and 324 and the perforated plates 321 and 322, respectively.

  In this case, the reason why the seal mechanisms 330 and 340 are configured is that hydrogen gas is fed in response to the deterioration of the cerium oxide 325 housed in the nitrogen gas purification device 300 and the inability to absorb oxygen gas. It is necessary to replace the cerium oxide 325, which has been drunk or deteriorated, but it is difficult to send hydrogen gas at the site where it is used, and in addition to the problem of generating moisture, consider the convenience. The nitrogen gas refining apparatus 300 in which the cerium oxide 325 in a state capable of absorbing oxygen gas is accommodated by first removing the nitrogen gas refining apparatus 300 while enabling the removal and attachment of the nitrogen gas refining apparatus 300 is provided. While trying to install and install, as a result, the nitrogen gas purification device 300 in a state capable of absorbing oxygen gas is stored until it is installed. Although, so as not to react with oxygen in the atmosphere at that time, the inlet and outlet of the nitrogen gas purifier 300 is to that to constitute the purpose of blocking the atmosphere.

  In addition, the reason for using the nonwoven fabrics 323 and 324 is that the shape of the cerium oxide 325 is powder or tablet, but naturally the powder is partly compressed with respect to the tablet. This is provided in order to prevent them from flowing downstream when they are powdered for reasons such as rubbing with each other while passing nitrogen gas. Further, the reason why the perforated plates 321 and 322 are used is to hold the soft nonwoven fabrics 323 and 324 described above.

  In this case, the nonwoven fabrics 323 and 324 may be made of polypropylene or polystyrene, and the perforated plates 321 and 322 may have a large number of holes made of iron, stainless steel, or aluminum so that nitrogen gas can flow. A punching plate with a gap between them can be considered, but a plastic plate having many holes may be used. Note that the perforated plates 321 and 322 and the nonwoven fabrics 323 and 324 may be provided only on the downstream side in consideration of the outflow. And provided on both sides.

  As shown in FIG. 2, the nitrogen gas purification device 300 is fixed to the stand 351 by the bands 352 and 353 and the patch's locks 354 and 355, but it is not necessary to be particular about fixing by this method.

  On the other hand, as shown in FIG. 2, the cartridge 310 has a cylindrical cartridge body 311 formed with a ridge at both ends, and a lid 312 positioned at the lower part on the inlet side and the upper part on the outlet side. 313, and the cartridge body 311 and the lid 312 including the sealing materials 314 and 315 such as packing, O-ring and liquid packing, and the sealing materials 314 and 315 located between the cartridge body 311 and the lids 312 and 313. , 313, and a plurality of bolts 316 that are fixed to each other.

  The cartridge body 311 may be made of iron or stainless steel as a material. The cartridge body 311 is integrally formed with seats 311a and 311b for holding the nonwoven fabrics 323 and 324 and the perforated plates 321 and 322 at substantially the same distance from the lower and upper ends. Accordingly, two perforated plates 321 on the lower side and the upper side so as to form spaces 311x and 311y between the cross section along the fluid flow of the cartridge 310 and the lower and upper ends, respectively. 322 is positioned, and the nonwoven fabrics 323 and 324 are positioned between the perforated plates 321 and 322 and the seats 311a and 311b. In this case, with respect to the number of seats 311a and 311b, three or four places can be considered equally on the top and bottom. Further, it is conceivable that the space between the cartridge body 311 and the seats 311a and 311b is welded or the like depending on the material.

  However, the seats 311a and 311b that hold the nonwoven fabrics 323 and 324 and the perforated plates 321 and 322 do not need to be limited to this method. The intervals between the space portions 311x and 311y and the intervals between the nonwoven fabrics 323 and 324 have predetermined values. It is also possible to provide two cylinders having a smaller diameter than the cartridge main body 311 positioned in the space portions 311x and 311y and one cylinder having a smaller diameter than the cartridge main body 311 positioned between the nonwoven fabrics 323 and 324 on the premise that it can be secured. It is done.

  By the way, as the lids 312 and 313, materials such as iron and stainless steel can be considered. The lids 312 and 313 are integrally formed with bosses 312a and 313a as a lower part on the inlet side or an upper part on the outlet side at the center. Further, female screws are formed inside the bosses 312a and 313a so that the on-off valves 290 and 510 can be directly connected. Further, on the inner side of the opposite side of the extension connected to the on-off valves 290 and 510 of the bosses 312a and 313a, a smooth surface effective for contacting the O-rings 332 and 342 is formed.

  Transparent holes 311f, 311g, 312g, and 313g using a transparent material are provided in the cartridge body 311 and the lids 312 and 313 so that the color change before and after the cerium oxide 325 reacts with oxygen can be confirmed. The pierced plates 321 and 322 are provided with the observation holes 321g and 322g, the nonwoven fabrics 323 and 324 are provided with the observation holes 323g and 324g, and the cerium oxide 325 can be visually observed.

  Further, as shown in FIGS. 3 and 4, the seal mechanisms 330 and 340 are composed of bodies 331 and 341 and O-rings 332 and 342.

  The bodies 331 and 341 have a cylindrical shape and the bottom portion is in a back contact state, and the bottom portion has a larger diameter than the other portions, forming bottoms 331a and 341a having ridges. It is. In addition, small holes 331g and 341g are formed at substantially central portions of the side surfaces of the bodies 331 and 341, and the inside and outside of the bodies 331 and 341 are communicated with each other.

  Therefore, as shown in FIG. 3, when removing the nitrogen gas purification device 300 and storing it after storing cerium oxide 325 capable of absorbing oxygen gas by reacting with oxygen gas, The O-rings 332 and 342 are attached to the outside of the bottoms 331a and 341a having the flanges, and the O-rings 332 and 342 are moved to move the O-rings 332 and 342 to the bosses 312a and 313a forming the lids 312 and 313. By making contact with the inside, the inside of the cartridge 310 is sealed. In this case, the protective plates 398 and 399 are attached so as to block the bosses 312a and 313a, thereby preventing foreign matters from entering and adhering to the upper portions of the bodies 331 and 341.

  On the other hand, as shown in FIG. 4, when the nitrogen gas purification device 300 is installed, the end portions of the on-off valves 290 and 510 are connected by attaching and connecting the on-off valves 290 and 510 after removing the protective plates 398 and 399. Are inserted into the internal threads of the bosses 312a and 313a forming the lids 312 and 313, and finally the bodies 331 and 341 are pushed out to form the bodies 331 and 341. When the bottoms 331a and 341a having the flanges are in contact with the perforated plates 321 and 322 and stopped, the inside of the cartridge 310 and the on-off valves 290 and 510 are communicated and opened by the small holes 331g and 341g. It is. It is also conceivable that the opening / closing valves 290, 510 can be used in place of the sealing mechanism without providing the sealing mechanisms 330, 340 by removing the nitrogen gas purifying apparatus 300 and the opening / closing valves 290, 510 in an integrated manner.

  Now, as shown in FIG. 1, the entire configuration including the nitrogen gas purification device 300 is shown. First, the compressor 110 generates compressed air, and the generated compressed air is manually compressed by a compressed air pipe 901. On-off valve 120 that can be opened and closed, compressed air piping 902, prefilter 140 that can separate large foreign matter, compressed air piping 903, and micro mist filter 150 that can separate small foreign matter The compressed air pipe 904, the activated carbon filter 160 capable of separating odors and colors, and the compressed air pipe 905 are fed into the nitrogen gas generator 210. In the compressed air piping 902, the pressure at that portion can be measured by the pressure gauge 130. By the way, some recent compressors 110 are provided with a dryer for drying compressed air, and those not installed may be provided downstream of the compressor 110.

In this case, the nitrogen gas generator 210 is based on the PSA system in FIG. 1, but can also be based on the membrane separation system. However, the nitrogen gas generator 210 need not be limited to the membrane separation method or the PSA method, and it may be possible to use nitrogen gas stored in a cylinder without using compressed air. As a matter of course, when the gas stored in the cylinder is used, it is not necessary to connect to the compressed air pipe 905, and it can be said that the nitrogen tank 220 shown below corresponds to the nitrogen gas generator 210.

  By the way, the PSA system is an abbreviation for Pressure Swing Adsorption, and passes compressed air through an adsorbent that is a kind of activated carbon, adsorbs a specific gas under a high pressure, and a specific gas under a low pressure. This is a method of separating nitrogen by adsorbing oxygen or the like from compressed air using the adsorbent's characteristic of exhaling. In this case, it has the same principle as a heatless dryer, and the apparatus is a two-cylinder type and larger than the membrane separation type, and a maintenance load such as a solenoid valve is also applied. In terms of nitrogen purity, it was usually about 99 to 99.9999%.

  On the other hand, in the membrane separation method, compressed air is sent into a hollow fiber membrane, which is a hollow fiber polymer membrane, and nitrogen is removed by utilizing the difference in permeation amount of each gas component contained in the compressed air to the membrane. This is a separation method. In this case, although it is smaller than the PSA method and has a smaller maintenance load, it is about 95 to 99.9% in terms of nitrogen purity, so it is not suitable for high purity needs.

  The hollow fiber membrane is made of polyester and is made of a bundle of thousands of straw-shaped hollow fibers. By passing compressed air through the hollow fiber, each gas has its own unique hollow fiber. By utilizing the difference in the permeation speed of the membrane, the nitrogen gas most contained in the air is left.

  And as the speed which the gas which comprises compressed air permeate | transmits the membrane of a hollow fiber, there exist gas which discharge | releases quickly and gas which is hard to discharge | release, and the remaining gas will be nitrogen gas. In particular, when the hollow fiber membrane is made of polyester, water vapor is most permeable, followed by hydrogen and helium, followed by carbon dioxide and carbon monoxide, and finally oxygen, argon and nitrogen are most permeable. The nitrogen gas is the gas that is most difficult to permeate.

  Here, when the temperature does not change, the purity of the generated nitrogen gas depends on the pressure and time of the compressed air, that is, the flow rate. In addition to polyester, resins such as polyolefin and polypropylene are also conceivable as the hollow fiber membrane.

  Therefore, the nitrogen gas separated by the nitrogen gas purification device 210 is divided into a nitrogen gas pipe 911, a nitrogen tank 220 for storing the nitrogen gas, a nitrogen gas pipe 912, a flow meter 250 for measuring the flow rate of the nitrogen gas, and a nitrogen gas. Low purity nitrogen gas 801 is fed into the nitrogen gas purification apparatus 300 via a pipe 913, an on-off valve 260 that can be manually opened and closed, a nitrogen gas pipe 914, and an on-off valve 290 that can be manually opened and closed. It is like that. In this case, in the nitrogen tank 220, the pressure of the portion can be measured by the pressure gauge 230, and in the nitrogen gas pipe 912, the oxygen concentration of the portion can be measured by the oxygen concentration meter 240. ing.

  Further, the high-purity nitrogen gas purified by the nitrogen gas purifying apparatus 300 includes a high-purity nitrogen gas pipe 915, a prefilter 520 that can separate large foreign matters, a high-purity nitrogen gas pipe 916, and small foreign matters. A high purity nitrogen gas pipe 917, a tank 540 for storing high purity nitrogen gas, a high purity nitrogen gas pipe 918, and a flow meter 570 for measuring the flow rate of nitrogen gas. The high-purity nitrogen gas 802 can be sent out via the high-purity nitrogen gas pipe 919 and the on-off valve 580 that can be manually opened and closed. In this case, the pressure of the portion can be measured by the pressure gauge 550 in the tank 540, and the oxygen concentration of the portion can be measured by the oxygen concentration meter 560 in the high purity nitrogen gas pipe 918. Is possible.

  By the way, a seal showing the history of the reproduction (manufacturing) number, the reproduction (manufacturing) date, the storage period, the name of the last confirmer, etc. is pasted on any location of the nitrogen gas purifying apparatus 300 to purify the nitrogen gas. After the device 300 is mounted, it is possible to manage the replacement by simultaneously reporting the date of mounting and returning the seal.

  Here, as an application example of the first embodiment, the cartridge body 311 may be made of a transparent plastic. However, since it is made of plastic, it is difficult to form a ridge on the cartridge main body 311, and the cylindrical end surface of the cartridge main body 311 is in direct contact with the lids 312 and 313 via the sealing materials 314 and 315. In this case, the lids 312 and 313 and the cartridge main body 311 are connected by through bolts and nuts. As a result, the inside of the cartridge main body 311 can be visually confirmed from the side surface of the cartridge main body 311, so that it is not necessary to form the transparent hole or the peep hole formed of iron or the like.

  The method and apparatus for purifying nitrogen gas according to the present invention is configured as described above, and its operation will be described below.

  In general, as the nitrogen gas generator 210, a membrane separation method or a PSA method is conceivable as a device for producing nitrogen gas at low cost. However, there is a disadvantage that the purity is low, and this causes a low purity. The present invention uses cerium oxide 325 that absorbs oxygen gas by reacting with oxygen gas from low-purity nitrogen gas separated from compressed air in the present invention. Thus, a nitrogen gas purification apparatus 300 that produces high-purity nitrogen gas 802 is shown.

  In this case, first, the compressor 110 is operated to generate compressed air, and the compressed air pipe 901, the on-off valve 120, the compressed air pipe 902, the prefilter 140, the compressed air pipe 903, the micro mist filter 150, the compressed air pipe 904, and activated carbon. By passing through the filter 160, clean compressed air is produced, and the compressed air is further fed into the nitrogen gas generator 210 through the compressed air pipe 905.

  Therefore, the nitrogen gas separated from the compressed air by sending the compressed air to the nitrogen gas generator 210 is temporarily stored in the nitrogen tank 220 via the nitrogen gas pipe 911, and further, the nitrogen gas pipe 912 and the flow meter 250. The low-purity nitrogen gas 801 is fed into the nitrogen gas purification apparatus 300 via the nitrogen gas pipe 913, the on-off valve 260, the nitrogen gas pipe 914, and the on-off valve 290.

  By the way, in the nitrogen gas purification apparatus 300, as seen in FIG. 4, the low purity nitrogen gas 801 from the on-off valve 290 hits the bottom 331 a having the gutter forming the body 331, and the body 331. The high purity nitrogen gas 802 is obtained by passing through the small hole 331g forming the gas and passing through the space 311x, the perforated plate 321, the nonwoven fabric 323, and the cerium oxide 325, and further the nonwoven fabric 324 and the hole. Through the perforated plate 322 and the space portion 311y, the gas flows out of the body 341 to the on-off valve 510 through the small hole 341g forming the body 341. In particular, the nonwoven fabric 324 is provided so that the powdered cerium oxide 325 does not flow downstream.

Here, the oxygen gas contained in the nitrogen gas is absorbed by the reaction found in [Equation 1] with cerium oxide 325. In this case, CeO ₂ is a regular structure of cerium oxide 325, and CeO _2-x indicates that some (x) oxygens are missing (deficient) from the regular structure. That is, [Equation 1], cerium oxide 325 with x number of oxygen vacancies have shown to be a cerium oxide 325 captures x-number of oxygen atoms from the outside (O _2/2).

  In this case, the cerium oxide-based oxygen scavenger has a characteristic of being black before oxygen absorption and becoming yellow after oxygen absorption. In order to utilize this property, transparent holes 312g, 313g, 311f, and 311g are provided in the lids 312 and 313 and the cartridge main body 311, and the inspection holes 321g, 322g, 323g, and 324g are provided in the perforated plates 321 and 322 and the nonwoven fabrics 323 and 324. By providing this, it is possible to confirm the color change of the cerium oxide 325 housed inside from the outside. As a matter of course, the seal members 314 and 315 have holes in necessary portions. However, when a transparent material is used for the cartridge body 311, it is not necessary to consider a transparent hole or a peep hole because the color change can be visually confirmed from the side surface.

  Further, the high purity nitrogen gas 802 from the on-off valve 510 removes the powdered cerium oxide 325 by the high purity nitrogen gas pipe 915, the pre-filter 520, the high purity nitrogen gas pipe 916, and the micro mist filter 530, thereby obtaining high purity nitrogen gas 802. The high-purity nitrogen gas 802 can be used via the gas pipe 917, the tank 540, the high-purity nitrogen gas pipe 918, the flow meter 570, the high-purity nitrogen gas pipe 919, and the on-off valve 580.

  In the present invention, in the case of a PSA system apparatus, 99.99% nitrogen gas passes through cerium oxide 325 as the low-purity nitrogen gas 801, and 99.99% as the high-concentration nitrogen gas 802. It is possible to produce 999%.

  By the way, when the apparatus of the present application is used and the purity of the high-concentration nitrogen gas 802 is lower than the intended purity, it means that the cerium oxide 325 has deteriorated until it cannot absorb oxygen gas. I can do it. Therefore, in order to replace the deteriorated cerium oxide 325 that cannot absorb oxygen gas, the nitrogen gas purifier 210 is removed, and after performing the following regeneration, as shown in FIG. 340, the O-rings 332 and 342 mounted with the O-rings 332 and 342 are in contact with the bosses 312a and 313a forming the lids 312 and 313, and the bosses 312a and 313a The protective paper 398, 399 is attached to the surface and stored.

  As a matter of course, instead of the removed nitrogen gas purifying apparatus 210, the stored nitrogen gas purifying apparatus 210 is attached. At that time, the protective paper 398 and 399 are removed, and the bodies 331 and 341 are moved. Thus, the O-rings 332 and 342 are positioned in a state where they are detached from the bosses 312a and 313a. As a result, as shown in FIG. 4, the small holes 331g and 341g are located in a state where the inside of the cartridge 310 and the on-off valves 290 and 510 can communicate with each other.

  The cerium oxide 325 can be regenerated by the reaction with the hydrogen gas found in [Equation 2]. In this case, as seen in [Equation 2], although water is generated, cerium oxide 325 can be taken out of the nitrogen gas purifier 210 and the reaction can be performed. In this case, treatment such as drying is also performed. It can be said that it can be done easily.

  The regeneration operation is performed by first removing the nitrogen gas purification device 300 in which the stored cerium oxide 325 is deteriorated and cannot absorb oxygen gas, and then the stored cerium oxide 325 removes oxygen gas. The nitrogen gas purification device 300 that can be absorbed is installed, and the nitrogen gas purification device 300 that was removed last is sent to a predetermined service station to perform a regeneration process. At the time of regeneration, cerium oxide 325 capable of absorbing oxygen gas is housed, and the O-rings 332 and 342 are moved to move the bodies 331 and 341 so that the bosses 312a and 313a forming the lids 312 and 313 are formed. The inside of the cartridge 310 is hermetically sealed and the protective paper 398 and 399 are attached to the inside of the cartridge 310 and stored in the service station depending on the customer.

  On the other hand, the nitrogen gas purifying apparatus 300 that has been regenerated in this way is sent to the customer by Takkyubin or the like, and is mounted and used again.

(Second embodiment)
As shown in FIGS. 1, 5, and 6, reference numeral 400 denotes a nitrogen gas purifier, which is similar to FIG. 2, and converts cerium oxide 325 that absorbs oxygen gas by reacting with oxygen gas to nitrogen. The gas purifier 400 is housed inside. In addition, regarding cerium oxide 325, it is possible to use either a powdery or molded tablet.

  By the way, the nitrogen gas purification apparatus 400 includes a cartridge 410, a seal mechanism 430 located on the lower side which is the inlet thereof, and a seal mechanism 440 located on the upper side which is the outlet thereof. The cerium oxide 325 is housed in the container, and the front and back of the cerium oxide 325 are held by nonwoven fabrics 423 and 424 and perforated plates 421 and 422.

  In this case, the reason why the seal mechanisms 430 and 440 are configured is the same as that in the first embodiment, and thus the description thereof is omitted.

The reason why the nonwoven fabrics 423 and 424 are used is the same as that in the first embodiment, and will be omitted.

  On the other hand, although the cartridge 410 is not specifically shown as a whole, referring to FIG. 2 of the first embodiment, the cartridge main body 411 having a cylindrical shape and forming ridges at both ends, Lids 412 and 413 located on the lower side which is the side and upper parts which are the outlet side, and a sealing material 414 such as packing, O-ring and liquid packing located between the cartridge body 411 and the lids 412 and 413 415 and a plurality of bolts for fixing between the cartridge main body 411 and the lids 412 and 413 including the sealing materials 414 and 415. By the way, the idea of the transparent cartridge main body 411 which does not form a ridge is considered to be the same as the first embodiment.

  The cartridge body 411 may be made of iron or stainless steel. The cartridge main body 411 has seats for holding the nonwoven fabrics 423 and 424 and the perforated plates 421 and 422 at substantially the same distance from both the lower and upper ends (the positions are the seats 311a and 311b in FIG. 2). It is good to think about it). Accordingly, two perforated plates 421 on the lower side and the upper side so as to form spaces 411x and 411y between the cross section along the fluid flow of the cartridge 410 and the lower and upper ends, respectively. 422 is positioned, and the nonwoven fabrics 423 and 424 are positioned between the perforated plates 421 and 422 and the seats 411a and 411b. In this case, with respect to the number of seats, three or four places can be considered equally on the top and bottom. Also, the space between the cartridge body 411 and the seat may be welded or the like depending on the material.

  Incidentally, the lids 412 and 413 may be made of iron or stainless steel. The lids 412 and 413 are integrally formed with bosses 412a and 413a at the center as a lower portion on the inlet side or an upper portion on the outlet side. Also, female screws are formed inside the bosses 412a and 413a so that the bodies 431 and 441 of the seal mechanisms 430 and 440 can be connected. Further, a smooth surface effective for contacting the O-rings 432, 433, 442, and 443 is formed on the inside of the bosses 412 a, 413 a having a reduced diameter on the opposite side of the extension connected to the bodies 431, 441. Forming.

  Transparent holes 411f, 411g, 412g, and 413g using a transparent material are provided in the cartridge body 411 and the lids 412 and 413 so that the change in color before and after the cerium oxide 325 reacts with oxygen can be confirmed. The pierced plates 421 and 422 are provided with the observation holes 421g and 422g, and the nonwoven fabrics 423 and 424 are provided with the observation holes 423g and 424g, so that the cerium oxide 325 can be visually observed.

  Further, as shown in FIGS. 5 and 6, the seal mechanisms 430 and 440 are composed of bodies 431 and 441 and O-rings 432, 433, 442 and 443.

  Note that the bodies 431 and 441 are shaped like cylinders that are stepped on the outside, and the bottoms are in the back contact state to form the bottoms 431a and 441a. Further, small holes 431g and 441g are formed in the bottoms of the side surfaces of the bodies 431 and 441, and grooves are formed on the outer sides thereof so that the inside and outside of the bodies 331 and 341 communicate with each other. Further, on the side opposite to the bottoms 431a and 441a, on-off valves 290 and 510 are connected by screwing.

  Accordingly, as shown in FIG. 5, the cerium oxide 325 capable of absorbing oxygen gas by removing the nitrogen gas purifier 400 integrally with the on-off valves 290 and 510 and reacting with the oxygen gas is housed. After that, when storing the O-rings 432, 433, 442, 443 outside the bottoms 431a, 441a, the bodies 431, 441 are moved and the O-rings 432, 433, 442, 443 are attached to the lid 412. By contacting the inside of the bosses 412a and 413a forming the 413, the inside of the cartridge 410 is sealed.

  In this case, the storage state is such that both the O-rings 432, 433, 442, and 443 are attached to the outside of the bottoms 431a and 441a and the bodies 431 and 441 are moved to move the upper portions of the bosses 412a and 413a and the body 431, 441, 441, 441, 499, and sandwiched between the spacers 498, 499, and fixed with tape to hold the positions of the O-rings 432, 433, 442, 443, body 431, 441 Is prevented from moving, and the on-off valves 290 and 510 are further attacked together to be closed to ensure a double sealed state. Note that it is conceivable that the on-off valves 290 and 510 are not integrally formed during storage.

  On the other hand, as shown in FIG. 6, when the nitrogen gas purifying apparatus 400 is installed, it is not possible to screw in any more by removing the split spacers 498, 499 and screwing the bodies 431, 441 into the bosses 412a, 413a. By inserting the nitrogen gas pipe 911 and the high-concentration nitrogen gas pipe 915 after that, the inside of the cartridge 410 and the on-off valves 290 and 510 communicate with each other through the small holes 431g and 441g. In this case, it can be said that the bottoms 431a and 441a are in a desirable positional relationship in which the perforated plates 421 and 422 are slightly pressed.

  The method and apparatus for purifying nitrogen gas according to the present invention is configured as described above, and its operation will be described below.

  Since the operation of the second embodiment is substantially the same as the operation of the first embodiment except for the operation of the nitrogen gas purification apparatus 400, the details are omitted. In this case, with respect to the operation of the nitrogen gas purification apparatus 400, the differences are as described. In particular, a seal showing the history of the reproduction (manufacturing) number, the reproduction (manufacturing) date, the storage period, the name of the last confirmer, etc. is pasted on any location of the nitrogen gas purification apparatus 400 to purify the nitrogen gas. After the device 400 is mounted, it is possible to manage the replacement by simultaneously reporting the date of mounting and returning the seal.

  The present invention relates to a technique and apparatus for purifying nitrogen gas, and more specifically, by reacting with oxygen gas from low-purity nitrogen gas mixed with oxygen gas that can be produced relatively cheaply. It describes the technology to produce high purity nitrogen gas using cerium oxide that absorbs oxygen gas. Especially in this invention, it has a great meaning not to use water. It can be said that it is particularly effective with respect to semiconductor manufacturing apparatuses that are disliked.

  Diagram showing the entire invention of the present application   The figure which showed the nitrogen gas refinement | purification apparatus of this invention, and the apparatus before and behind that   Upper detailed sectional view centering on the seal mechanism when storing the nitrogen gas purification apparatus of the present invention   Upper detailed sectional view centering on the sealing mechanism when the nitrogen gas purification apparatus of the present invention is installed   Upper detailed sectional view centering on the sealing mechanism when storing another nitrogen gas purification apparatus of the present invention   Upper detailed sectional view centering on the sealing mechanism when another nitrogen gas purification apparatus of the present invention is installed

Explanation of symbols

110 Compressor 120 Open / close valve 130 Pressure gauge 140 Prefilter 150 Micro mist filter 160 Activated carbon filter 210 ··· Nitrogen gas generator 220 ··· Nitrogen tank 230 ··· Pressure gauge 240 ··· Oxygen concentration meter 250 ··· Flow meter 260 · · · On-off valve 290 Open / close valve 300 Nitrogen gas refining device 310 Cartridge 311 Cartridge body 311a ... Seat 311b ... Seat 311f ... Transparent Hole 311g ... Transparent hole 311x ... Space 311y ... Space 312 ... Lid 312a ... Boss 312g ... Transparent hole 313 ... Lid 313a .... Boss 313 ··· Transparent hole 314 ··· Sealing material 315 ··· Sealing material 316 ··· Bolt 321 ··· Perforated plate 321g ··· Peep hole 322 ···・ Perforated plate 322 g... Peep hole 323... Nonwoven fabric 323 g... Peep hole 324... Nonwoven fabric 324 g... Peep hole 325. ... Seal mechanism 331 ... Body 331a ... Bottomed bottom 331g ... Small hole 332 ... O-ring 340 ... Seal mechanism 341 ... Body 341a ··· Bottom 341g with flange ··· Small hole 342 ··· O-ring 351 ··· Stand 352 ··· Band 353 ··· Band 354 ··· ..Patchon lock 355 ... Patchon lock 39 ... Protective paper 399 ... Protective paper 400 ... Nitrogen gas purifier 410 ... Cartridge 411 ... Cartridge body 411f ... Transparent hole 411g ... ··· Transparent hole 411x ··· Space portion 411y ··· Space portion 412 ··· Lid 412a ··· Boss 412g ··· Transparent hole 413 ··· Lid 413a ··· Boss 413g ... Transparent hole 414 ... Sealing material 415 ... Sealing material 421 ... Perforated plate 421g ... Peep hole 422 ... Perforated plate 422g ··· Peep hole 423 ··· Nonwoven fabric 423g ··· Peephole 424 · · · Nonwoven fabric 424g ···・ ・ ・ ・ Bottom 431g ・ ・ ・ ・ Small hole 432 ... O-ring 433 ... O-ring 440 ... Seal mechanism 441 ... Body 441a ... Bottom 441g ... Small hole 442 ... O-ring 443 ... O-ring 498 ... Spacer 499 ... Spacer 510 ... On-off valve 520 ... Pre-filter 530 ... Micro mist filter 540 ...... Tank 550 ... Pressure gauge 560 ... Oxygen concentration meter 570 ... Flow meter 580 ... Open / close valve 801 ... Low purity nitrogen gas 802... High purity nitrogen gas 901... Compressed air piping 902... Compressed air piping 903... Compressed air piping 904. ..Compressed air piping 911 ... Nitrogen gas piping 912 ... Elementary gas pipe 913 ... Nitrogen gas pipe 914 ... Nitrogen gas pipe 915 ... High purity nitrogen gas pipe 916 ... High purity nitrogen gas pipe 917 ... High Purity nitrogen gas pipe 918 ... High purity nitrogen gas pipe 919 ... High purity nitrogen gas pipe

Claims (11)

  Purification of nitrogen gas characterized by passing nitrogen gas mixed with oxygen gas through a nitrogen gas purification device (300, 400) containing cerium oxide (325) that absorbs oxygen gas by reacting with oxygen gas Method.   The nitrogen gas refining device (300, 400) can be used alone so that the cerium oxide (325) can be replaced in response to the stored cerium oxide (325) being unable to absorb oxygen gas. 2. The method for purifying nitrogen gas according to claim 1, wherein the front and rear on-off valves (290, 410) can be integrally attached and detached.   The nitrogen gas refining device (300) prevents the cerium oxide (325) from reacting with oxygen in the atmosphere during storage in an unused state in which the oxygen gas can be absorbed by reacting with the oxygen gas. 400). The method for purifying nitrogen gas according to claim 2, wherein an inlet and an outlet of 400) are shut off from the atmosphere.   By using the color change before and after the cerium oxide (325) reacts with oxygen, it can be determined that the cerium oxide (325) cannot react with oxygen any more. The method for purifying nitrogen gas according to any one of claims 1 to 3, wherein:   After determining that the cerium oxide (325) can no longer react with oxygen, it can be regenerated to a state where oxygen gas can be absorbed by injecting hydrogen gas. The method for purifying nitrogen gas according to claim 4.   A nitrogen tank (220) for storing nitrogen gas containing oxygen gas as an impurity, and a nitrogen gas purification device containing powdered or tablet-like cerium oxide (325) that absorbs oxygen gas by reacting with oxygen gas (300, 400) It is comprised, The refinement | purification apparatus of the nitrogen gas characterized by the above-mentioned.   The nitrogen gas refining device (300, 400) is singly adapted to replace the cerium oxide (325) in response to the stored cerium oxide (325) being unable to absorb oxygen gas. A cartridge (310,410) containing the cerium oxide (325), which can be attached and detached, and an upper part for sealing the cartridge (310,410) when stored; The apparatus for purifying nitrogen gas according to claim 6, comprising a sealing mechanism (330, 340, 430, 440) located at both lower portions.   The seal mechanism (330, 340, 430, 440) is used to store oxygen in the atmosphere while the cerium oxide (325) stored in the cartridge (310, 410) is stored in a state before use. So that both the inlet and outlet of the cartridge (310, 410) can be shielded from the atmosphere so that they do not react with the bottom (331a, 341a) or the bottom (431a, 441a) with a gutter, and a small hole (331g, 341g, 431g, 441g), and a body (331) in which an O-ring (332, 342, 433, 443) is mounted on the bottom (331a, 341a) or the bottom (431a, 441a) having the flange. 341, 431, 441), when stored, both the lower and upper side as the inlet and outlet of the cartridge (310, 410). The bosses (312a, 313a, 412a, 413a) formed integrally with the lids (312, 313, 412, 413) and the O-rings (332, 342, 433, 443) are brought into contact with each other to bring the cartridges (310, 410) into contact with each other. ) When the interior is sealed and installed, the boss (312a, 313a, 412a, 413a) formed integrally with the lid (312, 313, 412, 413) and the O-ring (332, 342, 433, 443) are installed. The apparatus for purifying nitrogen gas according to claim 7, wherein the cartridge (310, 410) is separated and opened in the small hole (331g, 341g, 431g, 441g).   Along the fluid flow of the cartridge (310, 410), the cerium oxide (325) in a state where a part of the powder or tablet is powdered for some reason does not flow downstream. And the lower and upper two perforated plates (321, 322, 421, so as to form spaces (311x, 311y, 411x, 411y) between the lower and upper ends, respectively. 422) is positioned with the non-woven fabric (323, 324, 423, 424) on the inside, and as a result, the space (311x, 411x), the perforated plate (321, 421) and the non-woven fabric along the flow of nitrogen gas (323, 423), the cerium oxide (325), the nonwoven fabric (324, 424), the perforated plate (322, 422), and the space (311y, 411y). Further purification device of the nitrogen gas according to claim 7 or claim 8, characterized in that they have installed prefilter (520) to remove foreign matter in the downstream of the nitrogen gas purifier (300, 400).   A seal showing the history is attached to any location of the nitrogen gas purification device (300, 400), and after the nitrogen gas purification device (300, 400) is mounted, the date of mounting and the return of the seal are simultaneously performed. The apparatus for purifying nitrogen gas according to any one of claims 6 to 9, wherein the exchange is managed as a result.   In order to confirm the color change before and after the cerium oxide (325) reacts with oxygen, the cartridge body (311 and 411) is made of a transparent material, or the cartridge body (311 and 411) and the lid (312). 313, 412, 413) are provided with transparent holes (311f, 311g, 312g, 313g, 411f, 411g, 412g, 413g) using a transparent material, and the perforated plates (321, 322, 421, 422) are provided. A peep hole (323g, 322g, 421g, 422g) was provided in the non-woven fabric (323, 324, 423, 424) with a peep hole (323g, 324g, 423g, 424g) to make the cerium oxide (325) visible. The apparatus for purifying nitrogen gas according to any one of claims 6 to 9, wherein:

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