JP4048245B2 - Method and apparatus for producing nitrogen gas - Google Patents

Description

  The present invention relates to a method and apparatus for producing nitrogen gas. More specifically, the present invention relates to a nitrogen gas produced by removing oxygen gas from compressed air. This is about the technology that makes high nitrogen gas easily and cheaply.

  Conventionally, as a technique related to a method for producing nitrogen gas and a production apparatus, there are generally three types: a PSA method, a membrane separation method, and a cryogenic separation method.

  Among them, the PSA method is an abbreviation for Pressure Swing Adsorption, and by passing compressed air through an adsorbent that is a kind of activated carbon, a specific gas is adsorbed under high pressure and specified under low pressure. This is a method of separating nitrogen gas by adsorbing oxygen gas or the like from compressed air, utilizing the characteristic of the adsorbent that exhales the gas. In this case, the principle is the same as that of a heatless dryer, the apparatus is a two-cylinder type and larger than the membrane separation type, and a maintenance load such as a solenoid valve is applied. In addition, the nitrogen gas concentration by this system was usually about 99 to 99.9999%.

  On the other hand, in the membrane separation method, compressed air is fed into a hollow fiber membrane that is a hollow fiber polymer membrane, and the difference in whether each gas component contained in the compressed air easily permeates the membrane is used. Thus, nitrogen gas is separated. In this case, although it is smaller than the PSA method and has a smaller maintenance load, since the nitrogen gas concentration is about 95 to 99.9%, it is not very suitable for needs of high concentration.

  Further, the cryogenic separation method is for needs of a large amount and a high concentration, and is separated and generated by cooling air. For example, when air is set to around -190 ° C, the boiling point of nitrogen is -198.5 ° C and the boiling point of oxygen is -183.0 ° C, so that oxygen can be liquefied and separated. In this case, nitrogen gas having a high concentration of 99.999% or more can be obtained, but a large-scale facility is required. On the other hand, in addition to transportation by tank lorries, a method was also employed in which piping was installed by installing a plant in the factory premises of large-scale users or in adjacent areas.

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

  First, in the case of the PSA method, the apparatus becomes large, and there is a difficulty in maintenance of apparatuses such as solenoid valves. Further, when the flow rate was increased, there was a difficulty in concentration.

  Next, in the case of the membrane separation method, the concentration of nitrogen gas is about 95 to 99.9%, which is not suitable for high concentration needs.

  Finally, in the case of the cryogenic separation method, nitrogen gas having a high concentration of 99.999% or more can be obtained, but a large-scale facility is required.

  The present invention is characterized in that nitrogen gas produced by removing oxygen gas from compressed air is reacted with heated iron powder or heated magnesium powder to remove the remaining oxygen gas, and is further removed. Is characterized in that after heating the nitrogen gas produced by removing oxygen gas from the compressed air, the remaining oxygen gas is reacted and removed by contacting with the magnesium powder. The above problems have been solved by having an average particle size of 10 to 1000 μm and a heating temperature of 50 to 600 ° C.

In addition, the present invention brings the nitrogen gas into contact with the heated metal and the hollow fiber membrane 60 or the PSA-type nitrogen gas generator 40 that creates nitrogen gas by removing oxygen gas from the compressed air in the order in which the compressed air flows. A deoxygenation apparatus 500 for reacting and removing the remaining oxygen gas is disposed to produce a nitrogen gas having a higher concentration. Further, the hollow fiber membrane 60 or the nitrogen gas by the PSA method is used. A drying device 300 for drying compressed air is disposed upstream of the generator 40, and the deoxygenating device 500 is filled with iron powder 509 or magnesium powder , and further, compressed air is in order to flow, a nitrogen gas generator 40 according to the hollow fiber membrane 60 or PSA system produces nitrogen gas by removing oxygen gas from the compressed air, before The deoxygenation device 550 for removing by reacting the remaining oxygen gas by contacting the magnesium powder after heating the nitrogen gas is provided, further characterized in that to produce a high nitrogen gas density, and further, the The magnesium powder has the average particle size of 10 to 1000 μm, thereby solving the above-mentioned problems.

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

  First, the idea of a deoxygenation device made it possible to easily produce cheaper and higher concentration nitrogen gas.

  Secondly, by passing compressed air through two devices, a hollow fiber membrane and a deoxygenation device, it has become possible to easily produce cheaper and higher concentration nitrogen gas.

  Thirdly, by passing the compressed air through two devices, a PSA-type nitrogen gas generator and a deoxygenator, it has become possible to easily produce nitrogen gas with a higher concentration at a lower cost.

  Fourthly, by using iron powder or magnesium powder in the deoxygenation device and limiting the average particle size, it has become possible to easily produce cheaper and higher concentration nitrogen gas.

  Fifth, nitrogen gas is brought into contact with a heated metal, or nitrogen gas is heated and brought into contact with the metal, and in addition, the heating temperature is limited so that it is cheaper and lighter and more highly concentrated nitrogen gas. Can be created easily.

  Sixth, by providing a drying device that dries compressed air upstream of the hollow fiber membrane and the PSA-type nitrogen gas generator, it is possible to easily produce cheaper, lighter and more concentrated nitrogen gas. It became.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Here, FIG. 1 is a diagram of the first embodiment showing the whole of the present invention, FIG. 2 is a diagram of the second embodiment showing the whole of the present invention, and FIG. 3 is a diagram constituting the present invention. FIG. 4 is a diagram showing another deoxygenation device constituting the present invention.
(First Example)

  As shown in FIG. 1, reference numeral 10 denotes a compressor, which is not specifically shown, and is composed of an electric motor, a compressor main body, and an air tank, and transmits the rotation of the electric motor to the belt. The air is sucked into the main body to create compressed air, and specifically stored in an air tank (not shown). In this case, regarding the air tank, a configuration in which the air tank is disposed in the middle of the compressed air pipes 202, 203, 211 without being integrated with the compressor 10 is also conceivable.

  Here, the compressed air stored in the air tank of the compressor 10 includes a compressed air pipe 202, a filter 20 for removing foreign matters such as dust and oil mist contained in the compressed air, a compressed air pipe 203, A drying apparatus 300 that removes water vapor from the compressed air and dries it, and a hollow fiber membrane 60 that leaves the nitrogen gas due to the difference in permeation speed via the compressed air piping 211.

  In this case, the filter 20 is configured as a set in FIG. 1 for the purpose of removing foreign matters such as dust and oil mist, but the pre-filter for removing dust from compressed air and the oil from compressed air are removed. The mist filter and the micro mist filter may be divided into two groups for each purpose. Moreover, the structure which arrange | positions three sets, a prefilter, a micro mist filter, and an activated carbon filter is also considered.

  As an example, when the pre-filter has the ability to remove large foreign matters of 3 μm or more existing in compressed air, the micro mist filter removes small foreign matters of 0.01 μm or more present in compressed air. In some cases, an activated carbon filter capable of removing odors in compressed air may be disposed downstream of the micro mist filter. However, the ability of the filter is not limited to the stated ability.

  On the other hand, as long as the drying apparatus 300 has a function of drying compressed air, it can be a refrigeration type, a membrane type, silica gel, activated alumina, zeolite, or a combination thereof. Or any other method. In addition, the drain apparatus 300 can discharge drain water accumulated by dew.

  Next, the hollow fiber membrane 60 is made of a polyester made of a bundle of thousands of straw-shaped hollow fibers, and each gas has its own by passing compressed air through the hollow fibers. Since the permeation speed of the hollow fiber membrane is different, it is a device that leaves most nitrogen gas contained in the air.

In this case, the speed at which the gas constituting the compressed air permeates through the membrane of the hollow fiber includes a gas that is released quickly and a gas that is difficult to release, and the remaining gas is nitrogen gas.
In particular, when the hollow fiber is made of polyester, water vapor is most permeable, followed by hydrogen gas and helium gas, followed by carbon dioxide and carbon monoxide, and finally oxygen gas, argon gas and nitrogen gas. It is difficult to permeate, and among them, nitrogen gas is the most difficult gas to permeate. Various gases centered on the oxygen gas that permeated quickly are separated from the remaining nitrogen gas and discharged.

  When the temperature does not change, the concentration of the generated nitrogen gas depends on the pressure and time of the compressed air, that is, the flow rate. Therefore, a throttle capable of adjusting the flow rate upstream or downstream of the hollow fiber membrane 60, and in some cases, the compressed air piping 202, 203, 211 or any portion of the nitrogen gas piping 212, 207 described later. It can be said that disposing a valve is an effective method for increasing the concentration of nitrogen gas.

  In addition to polyester, resins such as polyolefin and polypropylene are also conceivable as the hollow fiber membrane.

  Here, the nitrogen gas remaining as a result of the compressed air passing through the hollow fiber membrane 60 passes through the nitrogen gas pipe 212, any one of the deoxygenating apparatuses 500 and 550, and the nitrogen gas pipe 207 to further increase the concentration. High nitrogen gas can be sent out. As for the deoxygenating devices 500 and 550, any of the deoxygenating device 500 shown in FIG. 3 and the deoxygenating device 550 shown in FIG. 4 may be used, and other methods are used. Is also possible.

  In this regard, the deoxygenation apparatus 500 is a container in which iron powder 509 is filled in a container 501, and heating means 520 for heating the iron powder 509 is disposed, and nitrogen gas is brought into contact with the heated iron powder 509. Therefore, the purpose is to remove oxygen gas contained in nitrogen gas by oxidation.

  In this case, it is desirable that the iron powder 509 has an average particle size of 10 to 250 μm. Furthermore, it is more desirable that the average particle size is 30 to 150 μm. Here, the smaller the particles, the more effective the oxidation reaction, but there are difficulties in producing small particles. On the other hand, the larger the particles, the less effective the oxidation reaction, but easier to manufacture.

  Furthermore, when the surface of the iron powder 509 is coated with activated carbon at a ratio of 15% by weight, it is effective for the oxidation reaction. That is, it is very effective to coat the surface of the iron powder 509 with activated carbon at a ratio of 5 to 25% by weight.

  Under such circumstances, the iron powder 509 is sandwiched between two punching plates 503 for the purpose of securing a space so that nitrogen gas can easily enter and exit the inlet 501a and the outlet 502a, and the punching plate 503 is sandwiched between the pipe support members. It is supported by 504.

  As described above, by placing the lid 502 on the container 501 and fixing with the bolt 505, the deoxygenation apparatus 500 includes the container 501, the lid 502, the iron powder 509, the punching plate 503, the support material 504, and the like. One of the nitrogen gas pipes 206 and 212 is connected to the population 501 a formed in the container 501, and the nitrogen gas pipe 207 is connected to the outlet 502 a formed in the lid 502. It is like that. However, the inlet and the outlet may be interchanged so that they are formed in the lid 502 and the container 501.

  Further, in the deoxygenation apparatus 500, the iron powder 509 filled in the container 501 can be heated by heating the periphery of the container 501 with the heating means 520. In this case, as the heating means 520, the inside of the container 501 may be heated, or both inside and outside may be heated. Further, as a heating method, it may be considered to be used alone or in combination by gas, steam or electricity.

  And as heating temperature in that case, it is desirable that it is 50-1500 degreeC. Furthermore, the heating temperature is more preferably 80 to 500 ° C. In this case, the higher the heating temperature, the more the oxidation reaction is promoted. On the other hand, when the heating temperature is high, the container 501 and the like have to pay attention to the high temperature from the viewpoint of strength and safety. Will occur.

  For the iron powder 509, magnesium powder may be used instead. In that case, it is desirable that the average particle size is 10 to 1000 μm. Furthermore, it is more desirable that the average particle size is 30 to 500 μm. In this case, as with the iron powder 509, the smaller the particles, the more effective the oxidation reaction, but there are difficulties in producing small particles. On the other hand, the larger the particles, the less effective the oxidation reaction, but easier to manufacture.

  Moreover, as heating temperature, it is desirable that it is 50-600 degreeC. Furthermore, the heating temperature is more preferably 80 to 500 ° C. In this case, the higher the heating temperature, the more the oxidation reaction is promoted. On the other hand, when the heating temperature is high, the container 501 and the like have to pay attention to the high temperature from the viewpoint of strength and safety. Will occur. In addition, in the case of magnesium powder, it is necessary to pay attention to safety because it reacts with water more easily than iron powder.

  On the other hand, the deoxygenation device 550 has a deoxygenation tank 530 filled with iron powder 509 in a container 501 and a heating tank 560 provided with a heating means 562 for heating nitrogen gas connected by a nitrogen gas pipe 565. Thus, the object is to remove the oxygen gas contained in the nitrogen gas by oxidation by bringing the heated nitrogen gas into contact with the iron powder 509.

  In this case, the average particle size of the iron powder 509 is the same as the concept described in the deoxygenation apparatus 500, including the activated carbon coating, and is omitted. In addition, the formation of the space portion by the punching plate 503 and the support member 504 is completely the same as the idea described in the deoxygenation apparatus 500, and therefore will be omitted.

  As described above, by placing the lid 502 on the container 501 and fixing with the bolt 505, the deoxygenation tank 530 has the container 501, the lid 502, the iron powder 509, the punching plate 503, the support material 504, and the like. A nitrogen gas pipe 565 is connected to an inlet 501 a formed in the container 501, and a nitrogen gas pipe 207 is connected to an outlet 502 a formed in the lid 502.

  The heating tank 560 includes a container 561 and a heating unit 562 for heating the container. One of the nitrogen gas pipes 206 and 212 is connected to the inlet 561a formed in the container 561, and the heating tank 560 is formed in the container 561. A nitrogen gas pipe 565 is connected to the outlet 561b.

  Here, regarding the heating means 562, the place where the heating means 562 is disposed is different from the deoxidation tank 530 filled with the iron powder 509, such as the heating tank 560, but the heating means described in the deoxygenation apparatus 500 is different. Since the concept of 520 is the same as the concept of the heating position and the heating method, it will be omitted. Similarly, the heating temperature is the same as that of the iron powder 509 described in the deoxygenation apparatus 500, and thus the description thereof is omitted.

  Further, regarding the use of magnesium powder in place of the iron powder 509, the same concept as described in the deoxygenation apparatus 500 can be taken for the average particle size and the heating temperature, and the description thereof will be omitted.

  It should be noted that both of the deoxygenating apparatuses 500 and 550 are respectively provided before and after the nitrogen gas pipes 206 and 212 and the nitrogen gas pipe 207 or between the nitrogen gas pipes 206 and 212 and the nitrogen gas pipe 207. It is conceivable to provide an opening / closing valve for opening / closing the flow path. Moreover, you may provide in any position of the compressed air piping 202, 203, 211.

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

  First, the compressor 10 is operated to take in the atmosphere and create compressed air in the air tank. Here, the compressed air produced in the air tank is sent to the hollow fiber membrane 60 via the compressed air pipe 202, the filter 20, the compressed air pipe 203, the drying device 300, and the compressed air pipe 211. . Accordingly, foreign matters such as dust and oil mist and moisture that degrade the hollow fiber membrane 60 are removed by the action of the filter 20 and the drying device 300.

  On the other hand, the hollow fiber membrane 60 removes water vapor, hydrogen gas, helium gas, carbon dioxide gas, carbon monoxide, argon gas, etc. mainly from oxygen gas contained in the compressed air, and sends out nitrogen gas remaining. Yes. That is, the oxygen-rich gas is used to discharge gas mainly oxygen gas, and the remaining nitrogen gas is sent to the nitrogen gas pipe 212. The concentration of this nitrogen gas is about 95-99.9%, It contains a small amount of another gas centered on oxygen gas.

  In this case, the nitrogen gas sent from the hollow fiber membrane 60 is sent from the nitrogen gas pipe 212 to any of the deoxygenating devices 500 and 550. Here, the nitrogen gas fed in contains a small amount of oxygen gas, but the oxygen gas is removed by reacting with the iron powder 509 filled in the deoxidizers 500 and 550 to form iron oxide. .

に示すように反応させることで、窒素ガスの濃度を低下させている酸素ガスを出来るだけ除去し、窒素ガスの濃度を高めているのである。 ここでは、鉄粉末５０９を加熱することで、または加熱した窒素ガスを鉄粉末５０９に接触させることで反応を促進させているのである。That is,

By performing the reaction as shown in FIG. 5, the oxygen gas that has decreased the concentration of nitrogen gas is removed as much as possible, and the concentration of nitrogen gas is increased. Here, the reaction is promoted by heating the iron powder 509 or bringing the heated nitrogen gas into contact with the iron powder 509.

  Incidentally, regarding the iron powder 509, the iron powder 209 of the figure showing the deoxygenation apparatus constituting the present invention shown in FIG. 3 is another deoxygenation apparatus constituting the present invention shown in FIG. The iron powder 209 in the figure showing the same reaction shows the same reaction. For example, by feeding nitrogen gas having a pressure of about 1 MPa of 99.5% with oxygen gas as the center of impurities, both are 99.999. % Can be increased.

  Here, regarding the iron powder 209 shown in FIG. 3 and FIG. 4, if the particles are fine, it reacts so much that oxygen is easily removed. On the other hand, it is quite difficult to process the iron powder 209 into fine particles. There is a side.

  Now, a difference in operation between the deoxygenation apparatus 500 of FIG. 3 and the deoxygenation apparatus 550 of FIG. 4 will be described. In the deoxygenation apparatus 500 of FIG. 3, the deoxygenation apparatus 500 filled with iron powder 509 is provided. While the container 501 is heated together with the iron powder 509 while the nitrogen gas flows, the deoxygenation device 550 in FIG. 4 uses the nitrogen gas heated in the heating tank 560 constituting the deoxygenation device 550. A difference can be seen in that it is fed into a deoxygenation tank 530 filled with iron powder.

に示すように反応させることで、窒素ガスの濃度を低下させている酸素ガスを出来るだけ除去し、窒素ガスの濃度を高めているのである。 また、マグネシュウム以外でも、金属であるならば、他の物でも構わない。 ここでは、マグメシュウム粉末を加熱することで、または加熱した窒素ガスをマグネシュウム粉末に接触させることで反応を促進させているのである。
（第二実施例）In the above description, the substance filled in the deoxidizers 500 and 550 has been consistently described as iron powder, but is not limited to iron powder. In the case of magnesium powder, ,

By performing the reaction as shown in FIG. 5, the oxygen gas that has decreased the concentration of nitrogen gas is removed as much as possible, and the concentration of nitrogen gas is increased. In addition to magnesium, other materials may be used as long as they are metals. Here, the reaction is promoted by heating the magnesium powder or by bringing the heated nitrogen gas into contact with the magnesium powder.
(Second embodiment)

  As seen in FIG. 2, the second embodiment is different from the first embodiment of FIG. 1 in that the first embodiment is the configuration of the compressed air pipe 211, the hollow fiber membrane 60, and the nitrogen gas pipe 212. In comparison, the second embodiment has a configuration of a compressed air pipe 204, a PSA-type nitrogen gas generator 40, a nitrogen gas pipe 205, a nitrogen gas tank 50, and a nitrogen gas pipe 206.

  In this case, the nitrogen gas tank 50 is disposed for the purpose of preventing pulsation, and may be positioned downstream of the deoxygenation apparatuses 500 and 550. Further, in the first embodiment, it may be disposed immediately downstream of the hollow fiber membrane 60 or downstream of the deoxygenation devices 500 and 550.

  On the other hand, the PSA-type nitrogen gas generator 40 is a device that produces nitrogen gas, and functions substantially the same as the hollow fiber membrane 60 except that the nitrogen gas concentration is usually about 99 to 99.9999%. You can think of it.

  The PSA-type nitrogen gas generator 40 is composed of a first adsorption tank 41 and a second adsorption tank 42, and in addition, solenoid valves 43, 44, 45, 46, 47, 48, 49, One throttle valve 281 and second throttle valve 282, and pipes 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257 in the apparatus, 258, 259, 260 and an exhaust pipe 270.

  More specifically, the apparatus internal pipes 241 and 246 are branched by connecting to the compressed air pipe 204. Further, the apparatus internal pipes 254 and 259 are integrally connected to the nitrogen gas pipe 205.

  In the meantime, the internal pipe 241 includes the electromagnetic valve 43, the internal pipe 242, the internal pipe 243, the first adsorption tank 41, the internal pipe 251, the first throttle valve 281, the internal pipe 252, the internal pipe 253, and the electromagnetic. The valve 48 and the in-device piping 254 are connected in the order described.

  Further, the apparatus internal pipe 246 includes the electromagnetic valve 44, the apparatus internal pipe 247, the apparatus internal pipe 248, the second adsorption tank 42, the apparatus internal pipe 256, the second throttle valve 282, the apparatus internal pipe 257, the apparatus internal pipe 258, and the electromagnetic valve. The valve 49 and the in-device piping 259 are connected in the order described.

  Furthermore, the apparatus internal pipe 244 is connected to the connection part between the apparatus internal pipe 242 and the apparatus internal pipe 243, and the apparatus internal pipe 249 is connected to the connection part between the apparatus internal pipe 247 and the apparatus internal pipe 248. Connect the solenoid valve 45, the in-apparatus pipe 245, the in-apparatus pipe 250, the electromagnetic valve 46, and the in-apparatus pipe 249 in the order described, and connect the exhaust pipe 270 to the connection between the in-apparatus pipe 245 and the in-apparatus pipe 250. It is.

  On the other hand, the internal pipe 255 is connected to the connection between the internal pipe 252 and the internal pipe 253, the internal pipe 260 is connected to the connection between the internal pipe 257 and the internal pipe 258, and the internal pipe 255 is The solenoid valve 47 and the in-device piping 260 are connected in the order described.

  The first adsorption tank 41 and the second adsorption tank 42 have a large oxygen adsorption capacity and a difference in adsorption speed between oxygen and nitrogen, and nitrogen is preferentially absorbed by air by preferentially absorbing oxygen under pressure. It contains a kind of activated carbon that can separate the gas and can easily desorb the adsorbed oxygen by returning to atmospheric pressure.

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

  In this case, the operation from the compressor 10 to the drying device 300 is the same as that in the first embodiment, and is therefore omitted.

  On the other hand, in the nitrogen gas generator 40 by the PSA method, the first adsorption tank 41 and the second adsorption tank 42 containing an adsorbent, which is a kind of activated carbon having a large oxygen adsorption capacity and oxygen and nitrogen adsorption speed, are configured. The nitrogen gas is separated and extracted from the compressed air by utilizing the characteristic of the adsorbent that oxygen gas is adsorbed under high pressure and oxygen gas is discharged under low pressure.

  Therefore, in the first adsorbing tank 41 and the second adsorbing tank 42 containing the adsorbing material, the pressurizing action (high pressure) and the depressurizing action (low pressure) by the action of the electromagnetic valves 43, 44, 45, 46, 47, 48, 49. In this way, only nitrogen gas can be separated and extracted from compressed air at a high concentration and supplied.

  In this case, the first adsorption tank 41 is pressurized by supplying compressed air, and the second adsorption tank 42 is depressurized to a normal pressure, so that the adsorbent of the first adsorption tank 41 has a large amount of oxygen gas at the beginning of adsorption. Because of the characteristics of adsorbing nitrogen and the large amount of adsorption under high pressure, high concentration nitrogen gas is sent to the nitrogen gas pipe 205, and the adsorbent in the second adsorption tank 42 separates and separates the adsorbed oxygen gas. Thus, a gas centered on oxygen gas is discharged from the discharge pipe 270.

  In this way, a large amount of nitrogen gas can be continuously supplied by alternately repeating the pressurization and depressurization operations of the first adsorption tank 41 and the second adsorption tank 42. . In order to alternately perform pressurization and depressurization, the piping in the apparatus 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, and 260 are formed by opening and closing the solenoid valves 43, 44, 45, 46, 47, 48, and 49. Omitted.

  In addition, a first throttle valve 281 and a second throttle valve 282 are arranged immediately downstream of the first adsorption tank 41 and the second adsorption tank 42. By adjusting the flow rate of the compressed air flowing through the second adsorption tank 42, due to seasonal factors, pipe resistance, and subtle differences in the apparatus such as the difference in size between the first adsorption tank 41 and the second adsorption tank 42 The difference or variation in the nitrogen gas concentration is provided in order to obtain a nitrogen gas with a high concentration by adjusting the concentration of the nitrogen gas so that the variation is small and the variation is small. However, the positions of the first throttle valve 281 and the second throttle valve 282 need not be located downstream of the first adsorption tank 41 and the second adsorption tank 42, and may be located upstream.

  In this way, the nitrogen gas having a concentration of about 99.9% is sent to the nitrogen gas tank 50 through the nitrogen gas pipe 205 to prevent pulsation and is stored in a shared manner.

  Next, the nitrogen gas stored in the nitrogen gas tank 50 can supply high-concentration nitrogen gas from the nitrogen gas pipe 207 via the nitrogen gas pipe 206 and the deoxygenating devices 500 and 550. However, the operation of the deoxidizers 500 and 550 is the same as that of the first embodiment, and is omitted here.

  However, unlike the nitrogen gas having a concentration of 99.5% produced by the hollow fiber membrane 60 of the first embodiment, the nitrogen gas produced by the PSA-type nitrogen gas generator 40 has a concentration of about 99.9%. Therefore, a nitrogen concentration of 99.999% or more can be secured.

  Diagram of the first embodiment showing the entire invention   Diagram of the second embodiment showing the whole of the present invention   The figure which showed the deoxidation apparatus which comprises this invention   The figure which showed another deoxygenation apparatus which comprises this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Compressor 20 ... Filter 40 ... Nitrogen gas generator 41 by PSA method ... First adsorption tank 42 ... Second adsorption tank 43 ... ... Solenoid valve 44 ... Solenoid valve 45 ... Solenoid valve 46 ... Solenoid valve 47 ... Solenoid valve 48 ... Solenoid valve 49 ... · Solenoid valve 50 ··· Nitrogen gas tank 60 ··· Hollow fiber membrane 202 ··· Compressed air piping 203 ··· Compressed air piping 204 · · · Compressed air piping 205 ··· Nitrogen Gas pipe 206... Nitrogen gas pipe 207... Nitrogen gas pipe 211... Compressed air pipe 212... Nitrogen gas pipe 241. 243... Equipment piping 244... Equipment piping 245... Equipment piping 2 6... Equipment piping 247... Equipment piping 248... Equipment piping 249... Equipment piping 250... Equipment piping 251. ················································································································································································· •・ In-apparatus piping 259.. .In-apparatus piping 260.. .In-apparatus piping 270... Exhaust pipe 281... First throttle valve 282. Drying device 500... Deoxygenation device 501... Container 501 a .. Inlet 502... Lid 502 a ... Outlet 503 .. Punching plate 504. · Bolt 509 · · · iron powder 520 · · · heating means 530 · · · - oxygen tank 550 .... deoxygenator 560 ... heating tank 561 .... container 561a · · · inlet 561b · · · outlet 562 ... heating means 565 .... nitrogen gas piping

Claims (7)

  Nitrogen gas produced by removing oxygen gas from compressed air is brought into contact with heated iron powder or heated magnesium powder, and the remaining oxygen gas is reacted to be removed. .   A method for producing nitrogen gas, comprising: heating nitrogen gas produced by removing oxygen gas from compressed air; then reacting and removing the remaining oxygen gas by contacting with the magnesium powder.   The method for producing nitrogen gas according to claim 1 or 2, wherein the magnesium powder has an average particle size of 10 to 1000 µm and a heating temperature of 50 to 600 ° C. A hollow fiber membrane (60) that creates nitrogen gas by removing oxygen gas from the compressed air in the order in which the compressed air flows, or a PSA-type nitrogen gas generator (40), and the nitrogen gas is brought into contact with the heated metal An apparatus for producing nitrogen gas, characterized in that a deoxygenation device (500) for reacting and removing the oxygen gas remaining in the step is disposed to produce nitrogen gas having a higher concentration. A drying device (300) for drying compressed air is disposed upstream of the hollow fiber membrane (60) or the nitrogen gas generator (40) by the PSA method , and the deoxygenation device (500) is made of iron powder ( 509) or a magnesium powder filling apparatus according to claim 4 , wherein the apparatus is filled with magnesium powder . A hollow fiber membrane (60) that creates nitrogen gas by removing oxygen gas from the compressed air in the order in which the compressed air flows, or a PSA-type nitrogen gas generator (40), and the nitrogen gas is heated and then contacted with the magnesium powder An apparatus for producing nitrogen gas, characterized in that a deoxygenation device (550) for reacting and removing the remaining oxygen gas is disposed to produce nitrogen gas having a higher concentration. The method for producing nitrogen gas according to claim 5 or 6 , wherein the magnesium powder has an average particle size of 10 to 1000 µm.

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