JPH0456763B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an ultra-purification device and a purification method for nitrogen, and more specifically, an ultra-purification device and a purification method for purifying nitrogen with increased purity obtained by conventional purification methods to an even higher purity. This is a method for effectively purifying nitrogen using this equipment, and is useful in the field of manufacturing highly integrated circuits, which has been making rapid progress in recent years, as well as in the field of high purity required for academic research. The purpose is to provide a means to easily and reliably obtain nitrogen. [Prior Art] Nitrogen gas is a useful gas whose demand is gradually increasing in fields such as electronic industry, chemical industry, steel, and shipbuilding. The method of producing high-purity liquid nitrogen by compressing air using a compressor, then performing adiabatic expansion, and then repeating this process to rectify the obtained liquid air under high pressure has been an industrial method. This is a method for producing nitrogen that is commonly practiced, and it is sold commercially by filling containers as liquid nitrogen or gaseous nitrogen. Nitrogen is a typical inert gas and is widely used in the fields mentioned above as an atmospheric gas during metal heat treatment and semiconductor manufacturing processes, but it is especially used in ultra-precision microfabrication for the electronics industry. In such cases, it is necessary to further refine the product immediately before using it in the processing step to remove impurities and ensure high purity. Especially when used in large quantities industrially, liquid nitrogen is vaporized and used through piping, but impurities such as oxygen, carbon monoxide, carbon dioxide, hydrogen, hydrocarbons, and moisture contained in the vaporized nitrogen are removed. An important issue is how to remove it quickly and reliably. In order to remove such impurities and purify nitrogen to high purity, various nitrogen gas purifiers have been commercially available and used. For example, gas purification equipment (product model numbers TIP-10, TIP-30, TIP-60, TIP-
100, TIP−200, TIP−300, TIP−400, TIP−
Commercially available gas purifiers such as
Carbon monoxide, hydrocarbons, hydrogen, etc. are oxidized using an oxidizing agent using metal oxides such as copper, converting them into carbon dioxide and water, and then impurities are removed using zeolite-based molecular sieves or activated carbon. The gas is purified by adsorbing and removing it. These commercially available gas purifiers are convenient and widely used for easily obtaining high purity nitrogen. According to the catalog of the equipment, the impurities in the gas purified by these commercially available gas purification equipment are as follows.

[Problem that the invention seeks to solve]

The above-mentioned commercially available gas purification equipment is convenient and excellent for obtaining high-purity nitrogen gas, but recent advances in the semiconductor industry suggest that it will be easier to manufacture highly integrated circuits in the future than at present. Furthermore, as ultra-precision and fine processing is required, it is expected that even higher purity nitrogen gas will be required, and there is already a strong demand for high purity gas for testing. In response to this demand, the technical problem to be solved by the present invention is to further reduce the concentration of impurities by an order of magnitude on the order of ppm, to about 0.01 ppm or less. [Means for Solving the Problems] As mentioned above, the inventors of the present invention have conducted extensive research into methods for purifying nitrogen and lowering the impurity concentration by an order of magnitude on the order of ppm compared to conventional methods. The present invention was completed by discovering an ultra-refining device and method for further refining high-purity gas that has been purified by a gas purifying device. The device of the invention comprises an inlet for the nitrogen gas to be purified;
An outlet for purified nitrogen gas, a gas channel connecting the gas inlet and the gas outlet, and an alloy of 15 to 30% by weight iron and 85 to 70% by weight zirconium provided in the middle of the gas channel. The ultra-purification apparatus includes at least one getter chamber filled with a getter consisting of the following: and a heating device for maintaining the adsorption reaction temperature of the getter. In addition, the method of the present invention involves passing the nitrogen gas to be purified through a metal oxide oxidation reactant layer at the oxidation reaction temperature, and then passing it through an adsorbent layer such as a zeolite molecular sieve. Nitrogen gas with low impurity content is purified using a purification method,
Furthermore, 15-30% by weight kept at a temperature of 20-500℃
The basic structure of the nitrogen purification method is that impurities contained in nitrogen are adsorbed and removed through a getter layer filled with a getter made of an alloy of iron and 85 to 70% by weight of zirconium. 15-30% by weight of iron and 85-70% by weight used in the present invention
As the alloy getter comprising zirconium in the weight percent, those described in US Pat. No. 4,306,887 can be used. Particularly preferred is 22 to 25% by weight because of the characteristics of the getter made of the above-mentioned iron-zirconium alloy that it selectively adsorbs other impurities without adsorbing nitrogen.
The getter consists of an alloy of iron and 75-78% by weight zirconium. These getters made of iron-zirconium alloys can virtually completely adsorb and remove impurities such as carbon dioxide, moisture, and hydrogen at temperatures of 20 to 500° C. without adsorbing substantially nitrogen. The iron-zirconium composition is preferably in the range of 15 to 30% by weight of iron and 85 to 70% by weight of zirconium. Above this range of zirconium, the alloy adsorbs substantial amounts of nitrogen which should not be adsorbed. If the amount of zirconium is less than this range, the efficiency of removing (adsorbing) active gas from nitrogen will decrease. The Getter alloy is preferably used in the form of an intermetallic compound. Since intermetallic compounds are easily pulverized, they are easy to handle in production, and their surface area is large, which increases their activity. The manufacturing method for these alloys is substantially the same as that disclosed in U.S. Pat. The desired alloy can be manufactured by performing the same operation without adding any additives, but it is manufactured and sold by SAES Getters SpA of Milan, Italy. Commercially available products are preferably used. The above-mentioned binary alloy type getter is provided in the middle of a gas flow path connecting the above-mentioned gas inlet and the above-mentioned gas outlet in an outer container in which an inlet for the nitrogen gas to be purified is provided and an outlet for the purified nitrogen gas. Both are filled into one filling section, and together with a heating device attached to the outer container to maintain the getter adsorption reaction temperature, constitute the nitrogen ultra-purification device of the present invention. Nitrogen to be purified is passed through this device and impurities are brought into contact with the getter and adsorbed and removed. As for the shape of the getter used in the getter filling part, it is more advantageous to have a pellet shape than a powder shape because it is easier to secure gaps for gas flow between the getters in the getter layer. Furthermore, it is easier to maintain a constant porosity in the getter layer when the getter is in the form of pellets with uniform particle size rather than in the form of small lumps with irregular sizes, which is convenient in designing the device. Therefore, the getter may be in the form of a powder or a small lump, but when designing and manufacturing an industrial nitrogen ultra-purification device, a getter in the form of pellets made by compressing alloy powder is used. is the preferred method. The apparatus of the present invention is provided with a heating device for maintaining the adsorption reaction temperature of the getter, but as will be explained later in the Examples section, the heating device can be used in various forms. The heating method can be electrical heating, heat medium flow heating, etc., and the heating location can be selected as appropriate, such as in the preheating part before the gas enters the getter filling part, around the getter filling part, inside the getter filling part, etc. . As long as the adsorption reaction in the getter proceeds smoothly and heating can be performed to obtain as uniform a temperature distribution as possible, the heating may be performed as necessary.
The heating methods and heating positions may be designed in various combinations. The getter filling portion in the device of the present invention may have a structure in which the getter is directly filled into the outer container, but the getter filling portion may be composed of at least one cartridge filled with the getter, It is also a preferred embodiment that the cartridge is easily attachable to and detachable from the outer container and is replaceable. The getter component in the present invention adsorbs and removes impurities by chemisorption accompanied by chemical changes, so it is consumed stoichiometrically and has a certain lifespan.
If you do not replace the getter after using it for a certain period of time, you will not be able to achieve the purpose of ultra-purification of nitrogen. Therefore, it is possible to adopt the method of handling the ultra-purification device together with the outer container containing the Getter and replacing the entire device as needed, but it is also possible to store the Getter in a cartridge and remove only the cartridge part from the outer container at an appropriate time. A method of exchanging can also be adopted. As for the cartridge, it is preferable to use a metal container with holes for easy passage of gas. The purpose of the ultra-purification equipment of the present invention is to purify each impurity component to about 0.01 ppm or less, so the equipment material that comes into contact with nitrogen gas must be polished to a dense and smooth surface with little gas adsorption. Alternatively, it is preferable to use an annealed metal that does not generate powder due to corrosion. Examples of such metal materials include stainless steel, Hastelloy, Incoloy, Monel alloy, etc., but are not limited to these, and various metal materials may be used as appropriate as long as they meet the above conditions. Can be used selectively. As for equipment materials that come into contact with nitrogen gas, we have mentioned that it is preferable to have a surface that is polished or annealed to have a dense, smooth surface with little gas adsorption.If we express the degree of smoothness numerically, It is preferable to use a material that has been polished so that the inner surface has a center line average roughness (Ra) value [Japanese Industrial Standard (JIS) B0601-1970] of 0.5 μm or less, preferably 0.25 μm or less. Although this value is not critical, it is recommended as a safe range. It is effective to use the smoothed part by internal polishing or annealing in the part that comes into contact with the gas passing through the getter chamber, but it is of course possible to use it in the part that comes into contact with the gas passing through the getter chamber. . Due to the design of the device, it is often difficult to use it only in the parts that come into contact with the gas after it has passed through the getter chamber. By using a tube whose inner surface has been smoothed by polishing or annealing, or by performing baking, it is possible to significantly shorten the time it takes to consistently obtain high-purity gas even with new equipment. In the device of the present invention, the means for solving the technical problem can be implemented by changing the embodiments in various ways as described above, and the above examples do not stop and do not depart from the scope of the present invention. However, it can be implemented in various modified forms. In the method of the present invention, it is essential to pass the nitrogen gas to be purified through the metal oxide-based oxidation reactant layer at the oxidation reaction temperature. By converting carbon monoxide into water and carbon dioxide and passing it through an adsorbent layer such as a zeolite-based molecular sieve to adsorb and remove most of the carbon monoxide, the adsorption ability of Getter used in the present invention for hydrocarbons such as methane can be improved. This is because it is necessary to make up for the shortage. Nitrogen gas with a low impurity content obtained by purification by known gas purification methods is treated with a getter consisting of an alloy of 15-30% by weight iron and 85-70% by weight zirconium held at a temperature of 20-500°C. Impurities contained in nitrogen are adsorbed and removed through the filled getter layer. If the reaction temperature for adsorbing impurities in nitrogen gas in the getter layer is below 20°C, the impurities will be adsorbed on the getter surface, but they will not be expected to diffuse into the getter, and the getter's original ability will not be fully demonstrated. However, in the temperature range of 20 to 500°C, the adsorption ability of the getter is fully exerted, and impurities diffuse into the getter, causing the appearance of the getter to decrease. The lifespan of will also be longer. On the other hand, in a temperature range of 500°C or higher, nitrogen gas is easily adsorbed by the getter, so the reaction temperature is reduced to 500°C.
It is not preferable to set the temperature above ℃. Among the above temperature ranges of 20 to 500°C, a temperature range of 350 to 450°C is most preferably selected. In this range, the adsorption rate is high and impurities are sufficiently diffused into the interior, while there is no risk of desorption of hydrogen, and this is the most recommended reaction temperature. <Examples> The present invention will be described in more detail below based on Examples. Examples of the nitrogen ultra-purification apparatus according to the present invention are illustrated in FIGS. 1 to 9. Figure 1 shows an outer container made of stainless steel pipe (SUS 304 TP listed in Japanese Industrial Standards JIS G3448) and surrounded by a heat insulating material 12, with a nitrogen gas inlet 1 at the top and a nitrogen gas outlet 2 at the bottom. Attach the lid body 14 to the top of the lid body 1.
A heater 6 is disposed as a heating device in the space 25 inside the outer container 3 through the getter 4, and a layer of getter 4 filled between the upper and lower buffers 16 and 15 is provided below the getter 6. The nitrogen ultra-purification device is shown placed on a perforated plate 7 supported by a support 13 attached to the holder. The getter is an iron (22-25% by weight) - zirconium (75-78% by weight) alloy getter manufactured and sold by SAES Getters Sochieta Per Accioni with a diameter of 3.
A cylindrical pellet with a height of 4 mm and a height of 4 mm was used. The buffers shown in 15 and 16 are small alumina balls with an outer diameter of 1 to 4 mm in order to eliminate uneven gas flow into the getter layer, prevent scattering of getter fine powder, and equalize temperature distribution. are piled up in layers to a height of about 5 to 50 mm. In this example, alumina small balls are used for the buffer, but this may be replaced with stainless steel balls or fine-mesh stainless steel mesh. A buffer does not necessarily need to be used, and another embodiment that does not use a buffer will be shown later. At the top of the buffers 15 and 16, temperature measuring seeds 2 are inserted with temperature sensors 18 and 17, respectively.
0,19 are attached. A chromel-alumel thermocouple was used as a temperature sensor. Nitrogen gas 9 to be purified is introduced from inlet 1,
It is heated by the heater 6, made into a uniform flow by the upper buffer 16, and flows into the getter layer 4.
The purified gas on which impurity gases have been adsorbed passes through the perforated plate 7 and is drawn out from the outlet 2. Further examples of the apparatus are shown in FIG. 2 and below. In addition,
Common parts are indicated by the same reference symbols throughout the figures, and the explanation thereof will be omitted or limited to the necessary extent. FIG. 2 shows an ultra-refining apparatus constructed in the same manner as in FIG. 2, except that an electric heater 21 is arranged around the outer container 3, and a thermocouple 22 for measuring the temperature thereof is provided. According to this example, temperature control of the getter layer becomes easy. In the examples shown in FIGS. 1 and 2, the getter layer 4 is directly filled inside the outer container 3, but it can also be formed separately. FIG. 3 shows this example, in which the getter 4 and buffers 15, 16 are housed in a cartridge 5 having perforated plates 7, 7. Therefore, after using the cartridge for a certain period of time, it is sufficient to remove the lid 14 and replace the cartridge 5 with a new one, making it possible to work more efficiently than the cartridge shown in FIGS. 1 and 2. FIG. 4 shows still another device 11, in which the outer container 3 has a double structure of an inner wall 24 and an outer wall 23, and a heat medium such as steam, etc. Cooling medium is now being distributed. A cartridge 5 is inserted inside the inner wall. A getter 4 is filled in the cartridge, and an electric heater 6 is placed inside the getter 4.
is buried, lead 8 (only one shown),
It is connected to an external power source via a terminal 12. The cartridge 5 has concentric porous inner and outer walls 26 supported by a support plate 13. A flange 27 is provided at the lower end of the inner wall 24, through which the gas inlet conduit 1 and the outlet conduit 2 pass. The conduit 2 serves as a support for the cartridge 5. The nitrogen gas 9 to be purified is introduced through the inlet 1 and enters the outer space 25;
After being appropriately heated, it flows into the getter layer 4 maintained at a predetermined temperature through the porous wall 26, is purified, flows out into the inner space 25', and is drawn out to the outlet 2. FIG. 5 shows another ultra-refining device 11. Outer container 3
has double walls, and the temperature can be controlled by introducing a heat medium into the space between them from an inlet 30 and discharging it from an outlet 31. A cartridge 5 having a getter layer 4 surrounded by a porous wall is disposed within the inner wall, and a heater 6 is arranged around the cartridge 5.
and connect it to an external power source via lead 8.
Nitrogen gas 9 to be purified is introduced from inlet 1 and preheated by a heating medium, then purified by passing through getter layer 4 maintained at a predetermined temperature by heater 6, and drawn out from outlet 2. FIG. 6 shows another ultra-purification apparatus 11, in which a cylindrical outer container 3 supports a cartridge 5 by plates (not shown) provided above and below. An electric heater 6 having leads 8 is disposed inside the cartridge 5, and a getter 4 is filled between upper and lower porous plates or buffer layers. FIG. 7 shows yet another device 11, in which the heat insulating material 1
An inner cylinder is provided inside the outer container 3 having inner and outer walls filled with getter 2, and a getter 4 is filled in the space therebetween. An electric heater 6 wound around a ceramic rod 36 is placed in the central space. Nitrogen gas 9 to be purified flows in through the inlet 1, and the purified gas passes through the getter 4 and exits through the outlet 2. FIG. 8 shows yet another ultra-refining device. This example is a variation of FIG. 3 and includes means for recovering the heat of the purified nitrogen. That is, the nitrogen 9 to be purified enters the heat exchanger 28 provided at the bottom of the device, is preheated by exchanging heat with the outlet gas, and then passes through the conduit 29 surrounded by the heat insulating material 12 from the inlet 1 at the top of the device. It flows towards getter layer 4. The purified gas enters the heat exchanger 28 and is cooled before exiting at the outlet 2. FIG. 9 shows yet another example of the device. Outer container 3
is a double-walled cylinder between which a heating medium is introduced through an inlet 33 and drawn out through an outlet 34. An airtight support cylinder 35 is arranged in the internal space of the outer container 3, the inside of which is horizontally partitioned by a plurality of outer hole plates 7, and the chambers formed by each pair of these plates are filled with a getter layer 4. . Further, an electric heater 6 is arranged in the getter layer, and leads 10,
10'. Nitrogen gas to be purified 9
The nitrogen gas flows in through the inlet 1, and the purified nitrogen gas flows out through the outlet 2. Next, an example using a specific getter composition will be described. The equipment used for gas analysis in the following examples is as follows. Gas analyzer - Gas chromatograph - Mass spectrometer TE-360B (manufactured by Anelva Coup) Gas chromatograph - FID MODEL GC-9A (manufactured by Shimadzu Corporation) Moisture meter - Hygrometer MODEL 700
(Manufactured by Panametric Co.) Surface roughness meter - Surf coder MODEL SE-3H
(KOSAKA Laboratory Co.Ltd) Example 1 Non-evaporable getter powder consisting of an alloy composition of 76.6% Zr and 23.4% Fe with a particle size of 50 to 250 μm in nitrogen gas as shown in Figure 1. Filled into ultra-purification equipment. The cylinder made of stainless steel (SUS304 - standard name mentioned above) has an outer diameter of 21.7 mm, an inner diameter of 17.5 mm, and a length of 350 mm.
It was warm in mm. 200mm of this was filled with getter, and the top and bottom were filled with alumina ball buffer material to a thickness of 10mm. This ultra-purification equipment has a temperature of 25℃ and a pressure of 6.
Kg/cm ² (gauge pressure) of impurity-containing nitrogen gas is 0.17
was introduced at a flow rate of /min. Nitrogen flows through the getter layer maintained at 375℃, and the pressure is 4Kg/cm ² from the outlet.
(gauge pressure). After starting the gas flow
After 40 minutes, the impurity level of the exit gas was measured with the results in the table.

[Table] The impurity level in the outlet gas did not change for 1030 hours. Example 2 A non-evaporable Getter alloy with the same composition and particle size as used in Example 1 was compression molded to a diameter of 3 mm and a length of 4 mm.
mm pellets were produced. These pellets were charged into the ultra-purification apparatus shown in FIG. The stainless steel (SUS304) cylinder had an outer diameter of 89.1 mm and an inner diameter of 83.1 mm. The length was 660mm. The length of the cylinder, including the 10 mm thickness of the upper and lower buffers (alumina spheres), occupied by the getter pellets was 185 mm. Impure nitrogen gas was introduced into the ultra-purifier at a temperature of 25° C., a pressure of 4 Kg/cm ² (gauge) and a flow rate of 12/min. The impure nitrogen gas was passed through a non-evaporable getter bed maintained at a temperature of 375° C. by a spiral resistance heater and exited at the outlet at a pressure of 3.95 Kg/cm ² (gauge pressure). Forty minutes after the start of nitrogen gas flow, the impurity level of this outflow gas was measured and the results shown in the table were obtained.

Table: Outlet impurity levels remained constant over 760 hours. Example 3 Pellets were prepared in the same manner as in Example 2 and filled into the cartridge shown in FIG. The cartridge had an outer diameter of 80 mm, an inner diameter of 78 mm, and a length of 244 mm. The same amount of pellets as in Example 2 was used. Cartridge example 2
It was placed in the same cylinder (but with a length of 719 mm). Impure nitrogen gas was flowed at the same inlet pressure, temperature and flow rate as in Example 2. The cartridge was maintained at 375°C.
The outlet gas composition became the same as in Example 2 40 minutes after the start of nitrogen gas flow. The impurity level in the outlet gas remained constant for 760 hours. Example 4 In Example 2, the inner surface roughness of the cylinder is Ra=0.5μm
(usually Ra = 2.5 μm), and the stainless steel outlet pipe has an outer diameter of 9.5 mm, an inner diameter of 7.5 mm, and a surface roughness of Ra =
The same experiment was conducted with the thickness of 0.2 μm. The results shown in the table were obtained 40 minutes after the first flow of nitrogen gas.

[Table] The impurity level in the outlet gas remained constant for 760 hours. Example 5 In this example, the nitrogen gas to be purified is first
A stainless steel (SUS304) cylinder with a diameter of 89.1 mm, an inner diameter of 83.1 mm, and a length of 660 mm was filled with porous powder CuO molded pellets (pellet dimensions were 3 mm in diameter and 4 mm in length) to a filling height of 185 mm, and the cylinder was kept at 450 °C. I passed it through the tube. Next, outer diameter 89.1mm, inner diameter 83.1mm, length
The refining process is carried out through a dryer kept at 25℃, which consists of a 350mm stainless steel (SUS304) cylinder filled with molecular sieve 5A (pellet dimensions: 3.2mm in diameter and 4mm in length) to a floor height of 200mm. The water vapor content of nitrogen gas should be reduced. This gas was treated according to the method of Example 2. The outlet pressure of the dryer, i.e. the inlet pressure of the ultra-refining equipment, is 4Kg/cm ² (gauge pressure).
It was hot. To see the effect of temperature, we varied the getter temperature. The results were as shown in the table.

【table】

[Table] As can be seen from the table, this getter has excellent purification ability in the temperature range of 20 to 500°C. Examples 6, 7 Non-evaporable powder with a particle size of 50 to 250 μm (average 150 μm) consisting of an alloy of 84% Zr and 16% Fe (Example 6) and an alloy of 71% Zr and 29% Fe (Example 7) by weight The getter powder was compressed to produce pellets with a diameter of 3 mm and a length of 4 mm. These pellets were loaded in the same manner as in Example 2 into a superpurifier of the same configuration. Impure nitrogen gas was introduced into the ultra-purifier at a temperature of 25° C., a pressure of 4 Kg/cm ² (gauge) and a flow rate of 12/min. The impure nitrogen gas was passed through a non-evaporable getter bed maintained at a temperature of 375° C. by a spiral resistance heater and exited at the outlet at a pressure of 3.95 Kg/cm ² (gauge). Forty minutes after the start of nitrogen gas flow, the impurity level of this outflow gas was measured and the results shown in the table were obtained.

Table: Outlet impurity levels remained constant for 960 hours and 690 hours, respectively.

[Brief explanation of the drawing]

1 to 9 are longitudinal cross-sectional views of embodiments of the apparatus of the present invention. 1...Nitrogen gas inlet, 2...Purified gas outlet, 3
... Outer container, 4 ... Getter, 5 ... Cartridge, 6 ... Heater, 7 ... Perforated plate, 8 ... Terminal, 9 ... Nitrogen gas, 10 ... Lead wire, 11 ...
...Nitrogen super purification device, 12...Insulating material, 13...Support, 14...Lid, 15...Lower buffer,
16... Upper buffer, 17, 18... Thermometer, 19, 20... Thermometer sheath, 21... Heater,
22... thermocouple, 23... outer wall, 24... inner wall,
25... Space, 26... Porous wall, 27... Flange, 28... Heat exchanger, 29... Conduit, 30...
...Heat medium inlet, 31...Heat medium outlet, 32...Lead wire tube, 33...Cooling liquid inlet, 34...Cooling liquid outlet, 35...Cartridge portion, 36...Ceramics.

Claims (1)

[Scope of Claims] 1. A metal oxide-based oxidation reactant layer into which nitrogen gas to be purified is introduced, means for maintaining the reactant layer at the oxidation reaction temperature, and purification of nitrogen from the gas from the reactant layer. an adsorbent layer, an inlet for introducing gas from the adsorbent layer, an outlet for the purified nitrogen gas, a gas flow path connecting the gas inlet and the gas outlet, and a gas flow path provided in the middle of the gas flow path. ~30 wt% iron and 85
An apparatus for ultra-purification of nitrogen comprising at least one getter chamber filled with a getter consisting of an alloy with ~70% by weight of zirconium and a heating device for maintaining the operating temperature of the getter. 2 The getter used in the getter filling part is made of iron.
2. The nitrogen ultra-purification device according to claim 1, which is in the form of pellets made by compressing zirconium alloy powder. 3. The device according to claims 1 and 2, characterized in that the composition of the alloy used for the getter is 22-25% by weight of iron and 75-78% by weight of zirconium. 4. The method according to any one of claims 1 to 3, wherein the alloy used for the getter is an iron-zirconium intermetallic compound. 5. Claim 1, characterized in that the getter filling part consists of at least one cartridge filled with the getter, and the cartridge is easily attachable to and detachable from the outer container and replaceable. The device according to any one of items 4 to 4. 6. The apparatus according to claim 5, wherein each cartridge is a perforated metal container filled with a getter. 7 For equipment materials that come into contact with nitrogen gas, the centerline average surface roughness (Ra) given by the amplitude average of the entire measurement section of the inner surface that comes into contact with nitrogen gas is
The device according to any one of claims 1 to 6, characterized in that a material with a diameter of 0.5 μm or less is used. 8. The apparatus according to any one of claims 1 to 7, further comprising a pretreatment device for removing hydrocarbons. 9 As a pre-treatment device for removing hydrocarbons, there is an oxidation device in which a metal oxide-based oxidizing agent layer is placed so as to pass nitrogen gas, and an oxidation device that removes impurities such as moisture, carbon monoxide, and carbon dioxide generated by the oxidation reaction. 9. The apparatus according to claim 8, further comprising an adsorption device provided with an adsorbent layer such as a zeolite-based molecular sieve so as to pass the nitrogen gas contained therein. 10 Purify the nitrogen gas to be purified by a known gas purification method in which the nitrogen gas to be purified is passed through a metal oxide oxidation reactant layer at the oxidation reaction temperature and then passed through an adsorbent layer such as a zeolite molecular sieve, The resulting nitrogen gas with low impurity content is further heated at 20 to 500℃.
A method for removing impurities contained in nitrogen by adsorption through a getter layer filled with a getter made of an alloy of 15 to 30% by weight of iron and 85 to 70% by weight of zirconium maintained at a temperature of Purification method. 11 15-30% by weight maintained at a temperature of 350-450℃
8. A method as claimed in claim 7, characterized in that a getter layer is used which is filled with a getter made of an alloy of iron and 85 to 70% by weight of zirconium.