CN110937583B

CN110937583B - Nitrogen making machine

Info

Publication number: CN110937583B
Application number: CN201911294484.4A
Authority: CN
Inventors: 盛文涛; 盛之圭; 周炜
Original assignee: Hangzhou Shengbo Purification Equipment Co ltd
Current assignee: Hangzhou Shengbo Purification Equipment Co ltd
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2021-05-18
Anticipated expiration: 2039-12-16
Also published as: CN110937583A

Abstract

The invention discloses a nitrogen making machine, which relates to the field of nitrogen making machines and comprises an air filter, an air compressor, an adsorption tower and a gas collecting tank which are sequentially communicated, and further comprises an oxygen processing tank, a condenser, a steam-water separator and a storage tank which are sequentially communicated, wherein the oxygen processing tank is communicated with the gas collecting tank, and a hydrogen tank is communicated with the oxygen processing tank. The invention has the following advantages and effects: by utilizing the catalytic reaction and chemical reaction principle of oxygen and hydrogen, the trace oxygen in the nitrogen reacts to generate water, and meanwhile, after the water is separated by utilizing the condenser and the steam-water separator, the rapid preparation and stable preparation of the high-purity nitrogen are realized, and the effect of conveniently obtaining the high-purity nitrogen is achieved.

Description

Nitrogen making machine

Technical Field

The invention relates to the field of nitrogen making machines, in particular to a nitrogen making machine.

Background

The principle of PSA nitrogen-making machine is that the difference of adsorption performance of molecular sieve to different gas molecules is used to separate gas mixture, and it uses air as raw material, and uses high-effective high-selective solid adsorbent to make selectivity to nitrogen and oxygen so as to separate out nitrogen and oxygen from air.

Chinese patent CN205517126U discloses a PSA nitrogen-making device, which comprises an adsorption tower, an air storage buffer tank, a diversion buffer economizer and a nitrogen storage tank, wherein the diversion buffer economizer and the nitrogen storage tank are respectively connected with the adsorption tower through pipelines.

When the nitrogen making device is used, the adsorption tower is used for treating and separating air, and then nitrogen is conveyed into the nitrogen storage tank. However, the adsorption tower has limited processing capacity, so that the output nitrogen gas contains a trace amount of oxygen, so that the nitrogen generator cannot obtain high-purity nitrogen gas, and the improvement is awaited.

Disclosure of Invention

The invention aims to provide a nitrogen making machine which has the effect of conveniently obtaining high-purity nitrogen.

The technical purpose of the invention is realized by the following technical scheme: the utility model provides a nitrogen making machine, is including air cleaner, adsorption tower and the gas collecting tank that communicate the setting in proper order, still including oxygen treatment tank, condenser, catch water and the holding vessel that communicates the setting in proper order, oxygen treatment tank intercommunication the gas collecting tank, and the intercommunication is provided with hydrogen tank on the oxygen treatment tank.

Through adopting above-mentioned technical scheme, when using above-mentioned nitrogen machine to get nitrogen gas, utilize air cleaner to filter the back to dust and mechanical impurity in the air earlier, reuse air compressor with clean air compression to required pressure again. Then, after the oxygen, the carbon dioxide and the water are adsorbed by an adsorption tower provided with a carbon molecular sieve, the gas flowing to the gas collecting tank is the nitrogen and the trace oxygen. When high-purity nitrogen is prepared, the nitrogen in the gas collection tank is discharged into the oxygen treatment tank, then the hydrogen in the hydrogen tank is quantitatively added into the oxygen treatment tank, and the hydrogen in the oxygen treatment tank and the trace oxygen in the nitrogen are subjected to catalytic reaction to remove the trace oxygen in the nitrogen. And finally, cooling the water vapor generated after the reaction in the nitrogen by using a condenser, thoroughly separating the water in the nitrogen by using a steam-water separator, and collecting the high-purity nitrogen in a storage tank to realize the preparation of the high-purity nitrogen. Therefore, by utilizing the catalytic reaction and chemical reaction principle of oxygen and hydrogen, the trace oxygen in the nitrogen reacts to generate water, and meanwhile, after the water is separated by utilizing the condenser and the steam-water separator, the rapid preparation and stable preparation of the high-purity nitrogen are realized, and the effect of conveniently obtaining the high-purity nitrogen is achieved.

The invention is further provided with: and the hydrogen tank is provided with a flow meter for controlling the opening and closing of the hydrogen tank.

Through adopting above-mentioned technical scheme, control the hydrogen gas jar through setting up the flowmeter and open and close, realize the ration of hydrogen in the hydrogen jar and discharge, realize simultaneously that the ration of hydrogen in the oxygen treatment jar adds and the high accuracy adds to realize thorough reaction and the accurate of oxygen and get rid of.

The invention is further provided with: the steam-water separator and be provided with the desicator between the holding vessel, the desicator includes first adsorption drying tower and second adsorption drying tower, be provided with the drier in the first adsorption drying tower, be provided with electric heating plate in the second adsorption drying tower.

By adopting the technical scheme, after the nitrogen passes through the steam-water separator, the nitrogen firstly passes through the first adsorption drying tower, at the moment, the desiccant is used for adsorbing moisture in the nitrogen, and then the nitrogen is introduced into the second adsorption drying tower. Subsequently, the electric heating sheet is electrified, and after the electric heating sheet heats the nitrogen, the moisture in the nitrogen is thoroughly removed, so that the nitrogen is thoroughly dried, the preparation and acquisition of high-purity nitrogen are realized, and the quality and the purity of the nitrogen are improved.

The invention is further provided with: the air filter comprises a strip-shaped filter pipe, a plurality of layers of partition plates are horizontally arranged in the filter pipe, the partition plates divide the filter pipe into a plurality of filter cavities, and a filter element is arranged in each filter; an air inlet cover and an air outlet cover are respectively connected to two ends of the filter pipe in a sliding manner, the air inlet cover and the air outlet cover are used for covering two ends of the filter cavity, and rubber pipes are respectively communicated with the air inlet cover and the air outlet cover; and a pull rod for clamping the outer wall of the filter pipe is arranged between the side walls of the two sides of the air inlet cover and the air outlet cover, and locking parts for fixing the pull rod are arranged on the outer walls of the two sides of the filter pipe.

By adopting the technical scheme, when the air filter works, the locking part is firstly released, then the pull rod is pulled to drive the air inlet cover and the air outlet cover to slide, and when the air inlet cover and the air outlet cover are communicated with the uppermost filter cavity, the pull rod is fixed by using the locking part, so that the air inlet cover and the air outlet cover are fixed. Subsequently, air is introduced into the air inlet cover along the rubber pipe, and after the air is filtered by the filter element, the clean air is discharged along the air outlet cover and the other rubber pipe to realize the filtration of the air. After the filter cavity is used for a period of time, the locking part is released, and then the pull rod is pulled to drive the air inlet cover and the air outlet cover to slide. When the air inlet cover and the air outlet cover are communicated with the filter cavity below, the pull rod is fixed by the locking part, so that the air inlet cover and the air outlet cover are fixed. The filter core that can utilize next filter chamber filters the air this moment, reciprocates in proper order, realizes the switching of a plurality of filter cores and uses, can clear up or change the filter core after using simultaneously. Consequently through setting up a plurality of filter chambers and filter core, realize the fast switch-over of a plurality of filter cores, consequently realize the filtration of not shutting down of air, also realize the clearance of not shutting down and the change of filter core simultaneously, improved the filtration efficiency of air and the preparation efficiency of nitrogen gas.

The invention is further provided with: the lateral wall level of filter tube is provided with a plurality of locking grooves, and is a plurality of locking groove is followed the direction of height evenly distributed of filter tube, the sticking department is located including inlaying locking lever that locks the inslot, the locking lever is used for conflicting the lower terminal surface of pull rod, and one end articulate in the inner wall that locks the groove, the one end up end of locking lever is provided with the locking piece, the lower terminal surface of pull rod is provided with rectangular shape and supplies the locking hole that the locking piece was pegged graft.

By adopting the technical scheme, when the pull rod is fixed, the locking rod is pulled to turn outwards, and then the pull rod is driven to move downwards until the locking block on the locking rod is inserted into the locking hole on the lower end face of the pull rod, so that the locking and fixing of the pull rod are realized. When the fixing of the pull rod is cancelled, the pull rod is driven to move upwards until the locking block on the locking rod is separated from the locking hole on the lower end face of the pull rod, and the locking rod is driven to reversely turn. The locking part is accommodated and released until the locking rod is embedded into the locking groove. Therefore, the structure is simple, the locking part with stable working process realizes quick locking and releasing of the pull rod, and quick switching and use of a plurality of filter cores are realized.

The invention is further provided with: the pull rod is including being fixed in the first body of rod of cover lateral wall admits air and being fixed in the second body of rod of the cover lateral wall of giving vent to anger, the first body of rod deviates from the one end terminal surface of the cover of admitting air is provided with the screw rod, the second body of rod deviates from the one end terminal surface of the cover of giving vent to anger rotates and is connected with the screwed pipe, and the screw rod with screwed pipe threaded connection.

Through adopting above-mentioned technical scheme, after fixing the pull rod, the screwed pipe of screwing, the screwed pipe is close to the first body of rod gradually this moment to drive the second body of rod and be close to the first body of rod, the cover that admits air this moment compresses tightly the both ends terminal surface of filter tube and baffle gradually with going out the gas cover, realizes compressing tightly of filter chamber sealed, thereby avoids appearing gas leakage phenomenon, realizes the stable filtration of air.

The invention is further provided with: and the side wall of one side of the air inlet cover, which is close to the air outlet cover, is provided with a sealing gasket.

Through adopting above-mentioned technical scheme, further increase the air inlet cover and go out the sealed of air cover between the filter chamber through setting up sealed pad, further avoid appearing the gas leakage phenomenon to realize the stable filtration of air.

The invention is further provided with: the filter core includes a pair of filter screen and sets up in a pair of absorption intermediate layer between the filter screen, it is a pair of the filter screen be the dogleg shape set up in the filter tube, and the department of buckling of filter screen supports tightly the inner wall of filter screen.

Through adopting above-mentioned technical scheme, when the air was through crossing the filter core, because filter screen and absorption intermediate layer are the dogleg shape and set up, consequently the air can be many times through the filter screen and absorb the intermediate layer to realize the thorough filtration of air, make the filtration of air more thorough.

The invention is further provided with: the adsorption interlayer comprises a coke interlayer, an active carbon interlayer and a calcium hydroxide interlayer which are sequentially arranged.

Through adopting above-mentioned technical scheme, through setting up coke intermediate layer, active carbon intermediate layer and calcium hydroxide intermediate layer and filtering grease, vapor and carbon dioxide in the air respectively, improve the filter effect of air, reduced the work burden of adsorption tower simultaneously.

In conclusion, the invention has the following beneficial effects:

1. by utilizing the catalytic reaction and chemical reaction principle of oxygen and hydrogen, the trace oxygen in the nitrogen is reacted to generate water, and meanwhile, after the water is separated by utilizing a condenser and a steam-water separator, the rapid preparation and stable preparation of high-purity nitrogen are realized, so that the effect of conveniently obtaining the high-purity nitrogen is achieved;

2. after the nitrogen is dried by the efficient dryer, the moisture in the nitrogen is thoroughly removed, the preparation and acquisition of high-purity nitrogen are realized, and the quality and purity of the nitrogen are improved;

3. by arranging the plurality of filter cavities and the filter elements, the rapid switching of the plurality of filter elements is realized, so that the non-stop filtration of air is realized, the non-stop cleaning and replacement of the filter elements are realized, and the filtration efficiency of air and the preparation efficiency of nitrogen are improved;

4. the length-adjustable pull rod is arranged, so that the pressing force of the air inlet cover and the air outlet cover on the filter pipe and the partition plate is adjusted, the filter cavity is compressed and sealed, the air leakage phenomenon is avoided, and the stable filtration of air is realized;

5. through setting up the filter screen of dogleg shape and adsorbing the intermediate layer, make the air can be many times through the filter screen and adsorb the intermediate layer, realize the thorough filtration of air for the filtration of air is more thorough.

Drawings

FIG. 1 is a schematic structural view of an embodiment;

FIG. 2 is a schematic structural view of an oxygen treatment canister of an embodiment;

FIG. 3 is a schematic view of the internal structure of the air filter of the embodiment;

FIG. 4 is a schematic structural view of a candle of an embodiment;

FIG. 5 is a schematic view showing the connection of the air filter of the embodiment;

fig. 6 is a partial enlarged view at a in fig. 5;

FIG. 7 is a schematic structural view of a drawbar of the embodiment;

fig. 8 is a schematic structural view of the dryer of the embodiment.

Reference numerals: 1. an air filter; 11. a filter tube; 12. a partition plate; 13. a filter chamber; 14. a filter element; 141. filtering with a screen; 142. adsorbing the interlayer; 143. a coke interlayer; 144. an activated carbon interlayer; 145. a calcium hydroxide interlayer; 15. an air intake hood; 16. an air outlet cover; 17. a rubber tube; 18. a pull rod; 181. a locking hole; 182. a first rod body; 183. a second rod body; 184. a screw; 185. a threaded pipe; 19. a locking groove; 2. an adsorption tower; 3. a gas collection tank; 4. an oxygen treatment tank; 41. a hydrogen tank; 42. a flow meter; 5. a condenser; 6. a steam-water separator; 7. a dryer; 71. a first adsorption drying tower; 72. a second adsorption drying tower; 73. a desiccant; 74. an electrical heating sheet; 8. a storage tank; 9. a locking portion; 91. a locking lever; 92. and locking the block.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1, a nitrogen generator comprises an air filter 1, an adsorption tower 2, a gas collecting tank 3, an oxygen treatment tank 4, a condenser 5, a steam-water separator 6, a dryer 7 and a storage tank 8 which are sequentially communicated.

As shown in fig. 1 and 2, the oxygen treatment tank 4 is communicated with the gas collecting tank 3, the hydrogen tank 41 is communicated with the oxygen treatment tank 4, and the hydrogen tank 41 is further provided with a flow meter 42 for controlling the opening and closing of the hydrogen tank 41.

When nitrogen gas is produced by the nitrogen producing machine, dust and mechanical impurities in the air are filtered by the air filter 1, and then the clean air is compressed to a desired pressure by the air compressor (not shown). Then, after the oxygen, the carbon dioxide and the water are adsorbed by an adsorption tower 2 provided with a carbon molecular sieve (not shown in the figure), the gas flowing to a gas collecting tank 3 is nitrogen and trace oxygen, so that the preparation of the nitrogen is realized.

When high-purity nitrogen is prepared, the nitrogen in the gas collecting tank 3 is discharged into the oxygen treatment tank 4, and then the hydrogen tank 41 is controlled to be opened by using the flowmeter 42, so that the hydrogen in the hydrogen tank 41 is quantitatively added into the oxygen treatment tank 4. Then, the hydrogen in the oxygen treatment tank 4 and the trace oxygen in the nitrogen are subjected to catalytic reaction to generate water, so that the trace oxygen in the nitrogen is removed.

And finally, cooling the water vapor generated after the reaction in the nitrogen by using a condenser 5, thoroughly separating and drying the water vapor in the nitrogen by using a steam-water separator 6 and a dryer 7, and collecting the high-purity nitrogen in a storage tank 8 to realize the preparation of the high-purity nitrogen.

As shown in fig. 3, the air filter 1 includes an elongated filter tube 11, and a plurality of layers of partition plates 12 are horizontally disposed in the filter tube 11. The filter tubes 11 are divided into a plurality of filter chambers 13 by partitions 12, and a filter element 14 is provided in each filter.

As shown in fig. 3 and 4, the filter element 14 includes a pair of filter screens 141 and an adsorption interlayer 142 disposed between the pair of filter screens 141, and the adsorption interlayer 142 includes a coke interlayer 143, an activated carbon interlayer 144, and a calcium hydroxide interlayer 145, which are sequentially disposed. The pair of filter screens 141 are disposed in the filter pipe 11 in a zigzag shape, and the bent portions of the filter screens 141 are pressed against the inner walls of the filter screens 141.

As shown in fig. 3 and 5, an air inlet cover 15 and an air outlet cover 16 are vertically and slidably connected to two ends of the filter pipe 11, and a sealing gasket is disposed on a side wall of the air inlet cover 15, which is close to the air outlet cover 16. The inlet cover 15 and the outlet cover 16 are used for covering two ends of the filter cavity 13, and rubber pipes 17 are communicated with the inlet cover 15 and the outlet cover 16.

As shown in fig. 3 and 5, a pull rod 18 is arranged between the two side walls of the inlet cover 15 and the outlet cover 16, the pull rod 18 is used for clamping the two side outer walls of the filter pipe 11, and the two side outer walls of the filter pipe 11 are both provided with locking parts 9 for fixing the pull rod 18.

When the air filter 1 works, the locking part 9 is firstly released, then the pull rod 18 is pulled to drive the air inlet cover 15 and the air outlet cover 16 to slide, and when the air inlet cover 15 and the air outlet cover 16 are communicated with the uppermost filter cavity 13, the pull rod 18 is fixed by the locking part 9, so that the air inlet cover 15 and the air outlet cover 16 are fixed.

The air is then passed along the rubber tube 17 into the inlet hood 15, where it is filtered by means of the filter element 14. And when the filter element 14 is in operation, the filter screen 141 and the adsorption interlayer 142 are arranged in a zigzag shape, so that air can pass through the filter screen 141 and the adsorption interlayer 142 for multiple times.

At this time, the dust and mechanical impurities in the air are adsorbed by the screen 141, and the grease, water vapor and carbon dioxide in the air are adsorbed by the coke interlayer 143, the activated carbon interlayer 144 and the calcium hydroxide interlayer 145, respectively. The clean air will then be discharged along the outlet hood 16 and another rubber tube 17, which will effect a filtering of the air.

After the filter cavity 13 is used for a period of time, the locking part 9 is released, and then the pull rod 18 is pulled to drive the air inlet cover 15 and the air outlet cover 16 to slide. When the air inlet cover 15 and the air outlet cover 16 are communicated with the filter cavity 13 below, the locking part 9 is used for fixing the pull rod 18, so that the air inlet cover 15 and the air outlet cover 16 are fixed. At this time, the air can be filtered by the filter element 14 in the next filter cavity 13, and the process is repeated in sequence, so that the multiple filter elements 14 can be switched to use, and the used filter elements 14 can be cleaned or replaced.

As shown in fig. 5 and 6, the side wall of the filter tube 11 is horizontally provided with a plurality of locking grooves 19, and the plurality of locking grooves 19 are uniformly distributed along the height direction of the filter tube 11. The locking portion 9 includes a locking lever 91 embedded in the locking groove 19, the locking lever 91 is used for abutting against the lower end surface of the pull rod 18, and one end is hinged to the inner wall of the locking groove 19. The locking bar 91 is provided with a locking block 92 at an upper end face of one end, and the pull rod 18 is provided with a long strip-shaped locking hole 181 (see fig. 7) for the locking block 92 to be inserted into.

When the pull rod 18 is fixed, the locking rod 91 is pulled to turn outwards, and the locking rod 91 drives the locking block 92 to gradually disengage from the locking groove 19. And then the pull rod 18 is driven to move downwards until the locking block 92 on the locking rod 91 is inserted into the locking hole 181 on the lower end surface of the pull rod 18, so that the pull rod 18 is locked and fixed.

When the fixing of the pull rod 18 is cancelled, the pull rod 18 is driven to move upwards until the locking block 92 on the locking rod 91 is disengaged from the locking hole 181 on the lower end surface of the pull rod 18, and the locking rod 91 is driven to reversely turn. The lock lever 91 is inserted into the lock groove 19, and then the lock portion 9 is received and released.

As shown in fig. 5 and 7, the pull rod 18 includes a first rod 182 fixed to the sidewall of the inlet cowl 15 and a second rod 183 fixed to the sidewall of the outlet cowl 16. The end surface of the first rod 182, which faces away from the inlet hood 15, is provided with a screw 184, the end surface of the second rod 183, which faces away from the outlet hood 16, is rotatably connected with a threaded pipe 185, and the screw 184 is in threaded connection with the threaded pipe 185.

After the pull rod 18 is limited and fixed, the threaded tube 185 is screwed, and the threaded tube 185 gradually approaches the first rod 182 and drives the second rod 183 to approach the first rod 182. Meanwhile, the air inlet cover 15 and the air outlet cover 16 gradually compress the end faces of the two ends of the filter pipe 11 and the partition plate 12 to realize the compression sealing of the filter cavity 13, so that the air leakage phenomenon is avoided, and the stable filtration of air is realized.

As shown in fig. 8, the dryer 7 includes a first adsorption drying tower 71 and a second adsorption drying tower 72, a desiccant 73 is provided in the first adsorption drying tower 71, and an electric heating sheet 74 is provided in the second adsorption drying tower 72.

When the nitrogen passes through the dryer 7, the nitrogen firstly passes through the first adsorption drying tower 71, at this time, the desiccant 73 can be used for adsorbing moisture in the nitrogen, and then the nitrogen is introduced into the second adsorption drying tower 72. Then, the electric heating sheet 74 is electrified, and after the nitrogen is heated by the electric heating sheet 74, moisture in the nitrogen is thoroughly removed, so that the nitrogen is thoroughly dried, and the preparation and acquisition of high-purity nitrogen are realized.

The specific embodiments are only for explaining the present invention, and the present invention is not limited thereto, and those skilled in the art can make modifications without inventive contribution to the present embodiments as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. The utility model provides a nitrogen generator, includes air cleaner (1), adsorption tower (2) and gas collection tank (3) that communicate the setting in proper order, its characterized in that: the device is characterized by further comprising an oxygen treatment tank (4), a condenser (5), a steam-water separator (6) and a storage tank (8) which are sequentially communicated, wherein the oxygen treatment tank (4) is communicated with the gas collection tank (3), and a hydrogen tank (41) is communicated with the oxygen treatment tank (4);

the air filter (1) comprises a strip-shaped filter pipe (11), a plurality of layers of partition plates (12) are horizontally arranged in the filter pipe (11), the filter pipe (11) is divided into a plurality of filter cavities (13) by the partition plates (12), and each filter is internally provided with a filter core (14);

an air inlet cover (15) and an air outlet cover (16) are respectively connected to two ends of the filter pipe (11) in a sliding manner, the air inlet cover (15) and the air outlet cover (16) are used for covering two ends of the filter cavity (13), and rubber pipes (17) are respectively communicated and arranged on the air inlet cover (15) and the air outlet cover (16);

a pull rod (18) for clamping the outer wall of the filter pipe (11) is arranged between the side walls of the two sides of the air inlet cover (15) and the air outlet cover (16), and the outer walls of the two sides of the filter pipe (11) are both provided with locking parts (9) for fixing the pull rod (18);

the side wall level of filter tube (11) is provided with a plurality of locking grooves (19), and a plurality of locking grooves (19) are evenly distributed along the height direction of filter tube (11), locking portion (9) is including inlaying locking lever (91) of locating in locking groove (19), locking lever (91) are used for conflicting the lower terminal surface of pull rod (18), and one end articulates in the inner wall of locking groove (19), the one end up end of locking lever (91) is provided with locking piece (92), the lower terminal surface of pull rod (18) is provided with rectangular shape and supplies locking hole (181) that locking piece (92) pegged graft;

the pull rod (18) comprises a first rod body (182) fixed on the side wall of the air inlet cover (15) and a second rod body (183) fixed on the side wall of the air outlet cover (16), a screw rod (184) is arranged on the end face, deviating from the air inlet cover (15), of the first rod body (182), a threaded pipe (185) is rotatably connected to the end face, deviating from the air outlet cover (16), of the second rod body (183), and the screw rod (184) is in threaded connection with the threaded pipe (185);

the locking hole (181) is provided on the outer periphery of the threaded pipe (185).

2. A nitrogen generator as claimed in claim 1, wherein: the hydrogen tank (41) is provided with a flow meter (42) for controlling the opening and closing of the hydrogen tank.

3. A nitrogen generator as claimed in claim 2, wherein: the drying device is characterized in that a dryer (7) is arranged between the steam-water separator (6) and the storage tank (8), the dryer (7) comprises a first adsorption drying tower (71) and a second adsorption drying tower (72), a drying agent (73) is arranged in the first adsorption drying tower (71), and an electric heating sheet (74) is arranged in the second adsorption drying tower (72).

4. A nitrogen generator as claimed in claim 1, wherein: and the side walls of one side, close to each other, of the air inlet cover (15) and the air outlet cover (16) are provided with sealing gaskets.

5. A nitrogen generator as claimed in claim 1, wherein: the filter element (14) comprises a pair of filter screens (141) and an adsorption interlayer (142) arranged between the pair of filter screens (141), the pair of filter screens (141) are arranged in the filter pipe (11) in a zigzag manner, and the bent part of each filter screen (141) is abutted against the inner wall of the filter pipe (11).

6. A nitrogen generator as claimed in claim 5, wherein: the adsorption interlayer (142) comprises a coke interlayer (143), an activated carbon interlayer (144) and a calcium hydroxide interlayer (145) which are arranged in sequence.