Circulating nitrogen purifier and nitrogen making method

Abstract

The invention relates to the technical field of gas purification, in particular to a circulating nitrogen purifier and a nitrogen making method.The circulating nitrogen purifier comprises an adsorption tower, a buffer tank, a steam-water separator and a membrane separation assembly which are sequentially communicated through pipelines. A first circulating assembly is arranged on the membrane separation assembly, is communicated with the adsorption tower and the buffer tank, and is used for regenerating the adsorption tower and circularly producing nitrogen. The invention aims to perform nitrogen circulating purification by adopting adsorption and membrane separation, and in the circulating purification process, an adsorption material and a membrane material can be regenerated, so that the service lives of the adsorption material and the membrane material are prolonged, and the running stability of the purifier is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas purification, and in particular to a circulating nitrogen purifier and a nitrogen production method. Background Art

[0002] Nitrogen plays an important role in many fields such as chemical industry, electronics, metal processing, food preservation, medical and health care. At present, the purification process of nitrogen generally includes the following steps: compression, filtration, catalytic deoxygenation, adsorption, cooling and drying, and purity inspection. The commonly used nitrogen deoxygenation methods are hydrodeoxygenation, adsorption deoxygenation, and reactive deoxygenation. Among them, hydrodeoxygenation is a process in which the residual oxygen in the general nitrogen and the added hydrogen react chemically to generate water under the action of a catalyst, and then the water is removed by drying to obtain high-purity nitrogen. However, the amount of H2 in the finished nitrogen may be too high and may not meet certain specific applications. Adsorption deoxygenation uses the principle of metal and oxygen reaction to generate metal oxides. It is generally applicable to the case where the oxygen content in the raw nitrogen is ≤0.1%. When the oxygen content in the raw gas is higher, the amount of deoxidizer will increase a lot, and the deoxidizer needs to be regenerated, and the regenerated gas will be vented. Reactive deoxygenation occurs under the action of a carbon-supported catalyst (at a certain temperature), whereby the residual oxygen in ordinary nitrogen reacts with the carbon provided by the catalyst itself to generate CO2, which is then removed in the subsequent stage to obtain high-purity nitrogen. However, the dust generated by the reaction of the carbon-supported catalyst with oxygen needs to be cleaned regularly, and the carbon-supported catalyst needs to be replenished regularly, which increases the cost of use.

[0003] Therefore, in the prior art, nitrogen is also purified by membrane separation materials. However, in the current nitrogen purification process, compressed air is generally directly passed into the membrane separation material. However, since the permeability of the membrane is greatly affected by environmental factors such as temperature and humidity, and there are impurities such as dust in the compressed air, the service life of the membrane separation material is affected. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a circulating nitrogen purifier and a nitrogen production method, which adopts adsorption and membrane separation to carry out nitrogen circulation purification, and in the circulation purification process, the adsorption material and the membrane material can be regenerated, thereby extending the service life of the adsorption material and the membrane material and improving the stability of the purifier operation.

[0005] The present invention solves the above technical problems by the following technical means: A circulating nitrogen purifier comprises an adsorption tower, a buffer tank, a steam-water separator and a membrane separation component which are connected in sequence. The membrane separation component is provided with a first circulation component which is connected with the adsorption tower and the buffer tank and is used for regenerating the adsorption tower and circulating nitrogen production.

[0006] According to the above technical means, trace gases and dust in compressed air can be removed through the adsorption tower, and then the gas can be cached through the buffer tank to avoid direct impact on the membrane separation component. The water in the gas can be removed through the steam-water separator, so that after the water vapor, trace gases and dust in the gas are removed, the impact on the membrane separation component is reduced. Then, through the action of the circulation component, the purified nitrogen can regenerate the adsorption tower and the membrane separation component. On the one hand, the service life of the adsorption material and the membrane material is extended. On the other hand, the use of purified nitrogen can avoid the introduction of other gases and reduce energy consumption.

[0007] Furthermore, the membrane separation assembly includes a first membrane separator and a second membrane separator, the first membrane separator is communicated with the steam-water separator, and the second membrane separator is communicated with the first membrane separator.

[0008] According to the above technical means, nitrogen can be circulated and purified through the first membrane separator and the second membrane separator to improve the purity of nitrogen. It can also serve as a backup when one of the membrane separators has a problem, thereby improving the stability of operation.

[0009] Furthermore, a nitrogen purity analyzer and a first valve are provided between the first membrane separator and the second membrane separator.

[0010] According to the above technical means, by adopting a nitrogen purity analyzer, the purity of nitrogen can be detected, which facilitates further processing of the purified nitrogen.

[0011] Furthermore, the first circulation component includes a first circulation pipe and a second circulation pipe, one end of the first circulation pipe and the second circulation pipe are both connected to the membrane separation component, the free ends of the first circulation pipe and the second circulation pipe are both connected to the adsorption tower, and the free end of the second circulation pipe is also connected to the cache tank.

[0012] According to the above technical means, the adsorption tower can be regenerated through the first circulation pipe and the second circulation pipe, and the gas that is not purified in time during the purification process can be discharged into the cache tank through the second circulation pipe connected to the cache tank, thereby improving the separation efficiency of the membrane separator.

[0013] Furthermore, the second circulation pipe includes a main pipe, a first branch pipe and a second branch pipe, one end of the main pipe is connected to the membrane separation assembly, one end of the first branch pipe is connected to the main pipe, and the other end is connected to the adsorption tower, one end of the second branch pipe is connected to the main pipe, and the other end is connected to the cache tank.

[0014] According to the above technical means, the gas in the membrane separator can be transported to the adsorption tower and the buffer tank respectively through the cooperation of the main pipe, the first branch pipe and the second branch pipe, which is simple and practical.

[0015] Furthermore, a gas analyzer is provided between the adsorption tower and the cache tank.

[0016] According to the above technical means, the gas content after adsorption by the adsorption tower can be detected by a gas analyzer, which is convenient for subsequent operations.

[0017] Furthermore, the purifier further comprises a drying tower and a storage tank, the membrane separation component and the drying tower are circulated with a second circulation component, and the drying tower is connected with the storage tank for storing the dried gas.

[0018] According to the above technical means, the purified nitrogen can be dried again by a drying tower, which is beneficial to the storage of nitrogen.

[0019] Furthermore, the second circulation component includes a third circulation pipe and a fourth circulation pipe, one end of the third circulation pipe is connected to the pipeline located after the nitrogen purity analyzer, and the other end is connected to the drying tower, and one end of the fourth circulation pipe is connected to the second membrane separator, and the other end is connected to the drying tower.

[0020] According to the above technical means, the first membrane separator and the second membrane separator can be regenerated through the third circulation pipe and the fourth circulation pipe, thereby extending the service life of the first membrane separator and the second membrane separator.

[0021] Furthermore, the third circulation pipe is connected to a third branch pipe, and a free end of the third branch pipe is connected to the first membrane separator.

[0022] According to the above technical means, the first membrane separator can be regenerated through the third branch pipe.

[0023] The present application also discloses a nitrogen production method of the circulating nitrogen purifier as described above, the nitrogen production method comprising the following steps: S1. The compressed air is passed into the adsorption tower, and the gas treated by the adsorption tower enters the cache tank for caching; S2. The gas in the buffer tank is sent to the steam-water separator, and after the steam-water separation, it is sent to the first membrane separator, and the nitrogen passing through the first membrane separator is tested for purity. When the nitrogen purity meets the preset value, it is passed to the drying tower; when the nitrogen purity is lower than the preset value, it is passed to the second membrane separator, and after separation again, it enters the drying tower; S3. After the nitrogen is dried in the drying tower, it enters the storage tank for storage.

[0024] According to the above technical means, by first adsorbing and caching the gas and then performing membrane separation after steam-water separation, nitrogen with higher purity can be obtained, and the purifier operates stably.

[0025] The above-mentioned solution has the following beneficial effects: 1. In the present application, the adsorption tower is set up to remove trace gases and dust in the compressed air, and then the gas is cached through the buffer tank to avoid direct impact on the membrane separation component. The water in the gas is removed through the steam-water separator, so that the water vapor, trace gases and dust in the gas are removed, reducing the impact on the membrane separation component. Then, through the circulation component, the purified nitrogen can regenerate the adsorption tower and the membrane separation component. On the one hand, the service life of the adsorption material and the membrane material is extended. On the other hand, the use of purified nitrogen avoids the introduction of other gases and can reduce energy consumption. 2. In the present application, by setting up the first circulation component and the second circulation component, the adsorption tower and the membrane separation component can be regenerated. The structure is simple and practical, and no new gas needs to be introduced during the regeneration process. On the one hand, it can reduce energy consumption, and on the other hand, it can reduce the impact of impurities in the purifier on the purity of nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present application may be further illustrated by non-limiting examples given in the accompanying drawings; Figure 1 is a schematic structural diagram of a circulating nitrogen purifier according to an embodiment of the present application; Figure 2 It is a structural schematic diagram of the adsorption tower in the embodiment of the present application; Figure 3 is a schematic structural diagram of the first membrane separator in an embodiment of the present application; Description of main symbols: 1. Adsorption tower; 11. Gas analyzer; 2. Buffer tank; 3. Soda separator; 4. First membrane separator; 41. Spare pipe; 42. Main pipe; 43. First branch pipe; 44. Second branch pipe; 5. Second membrane separator; 51. First circulation pipe; 6. Nitrogen purity analyzer; 7. Drying tower; 8. Storage tank; 9. Third circulation pipe; 91. Third branch pipe; 92. Fourth circulation pipe. DETAILED DESCRIPTION

[0027] The following describes the implementation of the present invention through specific specific embodiments, and those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the illustrations provided in the following embodiments are only for exemplary descriptions, and only schematic diagrams are shown, not physical diagrams, and cannot be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts in the figures may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the figures.

[0028] The same or similar numbers in the figures of the embodiments of the present invention correspond to the same or similar parts. In the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back" and the like indicate an orientation or position relationship based on the orientation or position relationship shown in the figure, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the figures are only used for illustrative purposes and cannot be understood as limitations on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances: In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations.

[0029] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0030] like Figure 1-3 As shown, the embodiment of the present application discloses a circulating nitrogen purifier, comprising an adsorption tower 1, a buffer tank 2, a steam-water separator 3 and a membrane separation assembly which are sequentially connected through pipelines. A first circulation assembly is arranged on the membrane separation assembly, and the first circulation assembly is connected to the adsorption tower 1 and the buffer tank 2, and is used to regenerate the adsorption tower 1 and circulate nitrogen.

[0031] In this embodiment, the adsorption tower 1 is connected to the compressed air source through a pipeline for delivering compressed air to the adsorption tower 1. In this embodiment, the compressed air source can be prepared by an air compressor, and the output of the compressed air can be controlled by setting a pipeline between the output port of the air compressor and the input port of the adsorption tower 1 and setting a flow valve on the pipeline.

[0032] In some embodiments, a filter valve is further provided on the pipeline between the air compressor and the adsorption tower 1 for preliminary filtering of impurities in the compressed air.

[0033] In this embodiment, if Figure 2 As shown, the adsorption tower 1 is an activated carbon adsorption tower 1, and the activated carbon is preferably coconut shell activated carbon, which can effectively absorb trace gases such as nitrogen oxides, sulfur oxides, and halides in the air.

[0034] In this embodiment, the output port of the adsorption tower 1 is connected to the buffer tank 2 through a pipeline, and a gas analyzer 11 is installed on the pipeline for detecting and analyzing the gas adsorbed by the adsorption tower 1. The qualified gas is passed into the buffer tank 2; and the unqualified gas is continuously circulated and adsorbed in the adsorption tower 1. The gas analyzer 11 can be a chromatograph, a gas detector, etc., and a suitable gas analysis device can be selected according to the actual situation.

[0035] In this embodiment, if Figure 1 and Figure 3 As shown, the membrane separation assembly includes a first membrane separator 4 and a second membrane separator 5. The input end of the first membrane separator 4 is connected to the steam-water separator 3 through a pipeline, and the second membrane separator 5 is connected to the first membrane separator 4 through a pipeline.

[0036] In this embodiment, the output end of the first membrane separator 4 is connected to the input end of the second membrane separator 5 through a pipeline, and a nitrogen purity analyzer 6 is installed on the pipeline here, which is used to detect and analyze the purity of the nitrogen purified by the first membrane separator 4. A first valve is installed on the pipeline here, and the first valve is located after the nitrogen purity analyzer 6. When the purity of the nitrogen purified by the first membrane separator 4 reaches a preset value, the first valve is closed. The nitrogen is transported to the drying tower 7, and the nitrogen dried by the drying tower 7 is detected by the humidity detector on the drying tower 7. After the dryness of the nitrogen meets the requirements, it is transported to the subsequent finished product storage tank 8. When the purity of the nitrogen purified by the first membrane separator 4 does not reach the preset value, the nitrogen is transported to the second membrane separator 5 for further purification. After the purity of the purified nitrogen reaches the preset value, it is transported to the drying tower 7. After the drying tower 7, the dryness of the nitrogen meets the requirements, and then it is transported to the subsequent finished product storage tank 8.

[0037] In this embodiment, a standby pipe 41 is connected between the output end of the steam-water separator 3 and the second membrane separator 5, and a second valve is installed on the standby pipe 41. When a problem occurs in the first membrane separator 4, the second valve can be opened through the standby pipe 41, and only the second membrane separator 5 can be used, thereby improving the stability of operation. When a problem occurs in the second membrane separator 5, the standby pipe 41 is closed, the first valve is closed, and only the first membrane separator 4 is used.

[0038] In this embodiment, the first circulation component includes a first circulation pipe 51 and a second circulation pipe. One end of the first circulation pipe 51 is connected to the second membrane separator 5, and the other end is connected to the adsorption tower 1, so that the second membrane separator 5 can transport the purified nitrogen to the adsorption tower 1 when working, and regenerate the activated carbon adsorption tower 1. The second circulation pipe includes a main pipe 42, a first branch pipe 43 and a second branch pipe 44. One end of the main pipe 42 is connected to the first membrane separator 4, one end of the first branch pipe 43 is connected to the main pipe 42, and the other end is connected to the adsorption tower 1, so that the nitrogen purified by the first membrane separator 4 can be used for the regeneration of the adsorption tower 1, thereby extending the service life of the adsorption tower 1. One end of the second branch pipe 44 is connected to the main pipe 42, and the other end is connected to the buffer tank 2, which is used to transport the nitrogen that has not been purified in time and the gas that needs to be emptied to reduce the damage to the nitrogen, and at the same time, reduce the separation pressure of the membrane separator and improve the separation efficiency of the membrane separator.

[0039] In this embodiment, flow valves are installed on the first circulation pipe 51 , the first branch pipe 43 and the second branch pipe 44 to control the opening and closing of the first circulation pipe 51 , the first branch pipe 43 and the second branch pipe 44 .

[0040] In this embodiment, a second circulation assembly is provided between the first membrane separator 4, the second membrane separator 5 and the drying tower 7. The second circulation assembly includes a third circulation pipe 9 and a fourth circulation pipe 92. One end of the third circulation pipe 9 is connected to the pipeline located after the nitrogen purity analyzer 6, and the other end is connected to the drying tower 7, and is used to transport the nitrogen purified by the first membrane separator 4 to the drying tower 7. One end of the fourth circulation pipe 92 is connected to the second membrane separator 5, and the other end is connected to the drying tower 7, and is used to transport the nitrogen purified by the second membrane separator 5 to the drying tower 7.

[0041] In this embodiment, fans are installed on the third circulation pipe 9 and the fourth circulation pipe 92, which are used to transport the dry gas in the drying tower 7 back to the first membrane separator 4 or the second membrane separator 5, so as to regenerate the first membrane separator 4 and the second membrane separator 5, thereby extending the service life of the first membrane separator 4 and the second membrane separator 5.

[0042] In this embodiment, the third circulation pipe 9 is connected to a third branch pipe 91, and the free end of the third branch pipe 91 is connected to the bottom of the first membrane separator 4, so that the third branch pipe 91 is separated from the pipeline between the first membrane separator 4 and the second membrane separator 5. On the one hand, it is beneficial to the transportation of purified nitrogen, and on the other hand, it will not affect the regeneration of the first membrane separator 4.

[0043] The present application also discloses a method for producing nitrogen using the circulating nitrogen purifier of the above embodiment, comprising the following steps: S1. Compressed air is passed through a pipeline into an activated carbon adsorption tower 1. The gas after the activated carbon adsorption tower 1 adsorbs trace gases is detected by a gas analyzer 11. When the gas analyzer 11 detects that it meets the preset value, the adsorbed gas is transported to a cache tank 2 for caching; when the gas analyzer 11 detects that it is lower than the preset value, the gas enters the adsorption tower 1 again for cyclic absorption until it meets the preset value; S2. The gas in the buffer tank 2 is sent to the steam-water separator 3, and after the steam-water separation, it is sent to the first membrane separator 4, and the nitrogen passing through the first membrane separator 4 is tested for purity. When the nitrogen purity meets the preset value, it is passed into the drying tower 7; when the nitrogen purity is lower than the preset value, it is passed into the second membrane separator 5, and after separation again, it enters the drying tower 7; S21. When the first membrane separator 4 is working, the gas to be evacuated is transported to the buffer tank 2 through the main pipe 42 and the second branch pipe 44, and then transported to the first membrane separator 4 through the buffer tank 2 for circulating nitrogen production; after the adsorption tower 1 has been working for a period of time, the adsorption tower 1 can be purged and regenerated by the nitrogen purified by the first membrane separator 4 through the main pipe 42 and the first branch pipe 43; and the adsorption tower 1 can be regenerated with high-purity nitrogen through the nitrogen purified by the second membrane separator 5 through the first circulation pipe 51; S3. After the nitrogen is dried in the drying tower 7, it enters the storage tank 8 for storage.

[0044] S31. After the first membrane separator 4 and the second membrane separator 5 have been working for a period of time, the first membrane separator 4 is purged and regenerated through the cooperation of the third circulation pipe 9 and the fan; the second membrane separator 5 is purged and regenerated through the cooperation of the fourth circulation pipe 92 and the fan; and the activated carbon adsorption tower 1 is regenerated by the nitrogen regenerated from use by the first membrane separator 4 and the second membrane separator 5. After the adsorption tower 1 is regenerated, the nitrogen is separated and purified again by the first membrane separator 4 and the second membrane separator 5, and is input into the drying tower 7 for drying, and then stored to realize the cycle of circulation and regeneration.

[0045] The above is a detailed introduction to a circulating nitrogen purifier and a nitrogen production method provided by the present invention. The description of the specific embodiment is only used to help understand the method and its core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0046] It should be noted that the phrases "one embodiment", "embodiment", "some optional embodiments", "exemplary embodiments", "some embodiments", etc. mentioned in the specification indicate that the described embodiment may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing specific features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A circulating nitrogen purifier, characterized in that: The invention comprises an adsorption tower (1), a buffer tank (2), a steam-water separator (3) and a membrane separation component which are connected in sequence, wherein a first circulation component is arranged on the membrane separation component, and the first circulation component is connected to the adsorption tower (1) and the buffer tank (2) and is used for regenerating the adsorption tower (1) and circulating nitrogen production.

2. The circulating nitrogen purifier according to claim 1, characterized in that: The membrane separation assembly comprises a first membrane separator (4) and a second membrane separator (5), wherein the first membrane separator (4) is connected to a steam-water separator (3), and the second membrane separator (5) is connected to the first membrane separator (4).

3. The circulating nitrogen purifier according to claim 2, characterized in that: A nitrogen purity analyzer (6) and a first valve are arranged between the first membrane separator (4) and the second membrane separator (5).

4. The circulating nitrogen purifier according to claim 1 or 3, characterized in that: The first circulation component comprises a first circulation pipe (51) and a second circulation pipe, one end of the first circulation pipe (51) and the second circulation pipe are both connected to the membrane separation component, the free ends of the first circulation pipe (51) and the second circulation pipe are both connected to the adsorption tower (1), and the free end of the second circulation pipe is also connected to the buffer tank (2).

5. The circulating nitrogen purifier according to claim 4, characterized in that: The second circulation pipe comprises a main pipe (42), a first branch pipe (43) and a second branch pipe (44); one end of the main pipe (42) is connected to the membrane separation assembly; one end of the first branch pipe (43) is connected to the main pipe (42) and the other end is connected to the adsorption tower (1); one end of the second branch pipe (44) is connected to the main pipe (42) and the other end is connected to the buffer tank (2).

6. The circulating nitrogen purifier according to claim 1, characterized in that: A gas analyzer (11) is provided between the adsorption tower (1) and the buffer tank (2).

7. The circulating nitrogen purifier according to claim 3, characterized in that: The purifier further comprises a drying tower (7) and a storage tank (8), wherein the membrane separation component and the drying tower (7) are circulated with a second circulation component, and the drying tower (7) is communicated with the storage tank (8) for storing the dried gas.

8. The circulating nitrogen purifier according to claim 7, characterized in that: The second circulation component comprises a third circulation pipe (9) and a fourth circulation pipe (92), wherein one end of the third circulation pipe (9) is connected to a pipeline located after the nitrogen purity analyzer (6), and the other end is connected to a drying tower (7); one end of the fourth circulation pipe (92) is connected to the second membrane separator (5), and the other end is connected to the drying tower (7).

9. The circulating nitrogen purifier according to claim 8, characterized in that: The third circulation pipe (9) is connected to a third branch pipe (91), and the free end of the third branch pipe (91) is connected to the first membrane separator (4).

10. A method for producing nitrogen using a circulating nitrogen purifier according to any one of claims 1 to 9, characterized in that: The nitrogen production method comprises the following steps: S1. The compressed air is passed into the adsorption tower (1), and the gas treated by the adsorption tower (1) enters the cache tank (2) for caching; S2. The gas in the buffer tank (2) is sent to the steam-water separator (3), and after the steam-water separation, the gas is sent to the first membrane separator (4), and the nitrogen passing through the first membrane separator (4) is tested for purity. When the nitrogen purity meets the preset value, the nitrogen is passed to the drying tower (7); when the nitrogen purity is lower than the preset value, the nitrogen is passed to the second membrane separator (5), and after separation again, the nitrogen is passed to the drying tower (7); S3. After the nitrogen is dried in the drying tower (7), it enters the storage tank (8) for storage.

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