High-temperature pressure swing adsorption pure oxygen production equipment

Abstract

The application provides a high-temperature pressure swing adsorption pure oxygen production equipment, which comprises a filter, an inlet of the filter is connected with an air pipeline, an outlet of the filter is connected with an inlet of a blower, an outlet of the blower is connected with an inlet of an air buffer tank, the blower is connected with a frequency converter, an outlet of the air buffer tank is connected with a first inlet of an adsorption tower, a second inlet of the adsorption tower is connected with an outlet of an oxygen back flushing tank, an outlet of the adsorption tower is connected with an inlet of a vacuum pump, an inlet of the oxygen back flushing tank is connected with an outlet of an oxygen buffer tank, the oxygen buffer tank is connected with an oxygen analyzer or a chromatograph and an oxygen flow meter, an outlet of the oxygen buffer tank is connected with an air outlet pipeline, and an outlet of the vacuum pump is connected with the air outlet pipeline. The application uses the principle of pressure swing adsorption, proposes a novel pressure swing adsorption process and equipment, breaks through the limitation of product oxygen purity, and obtains oxygen with a purity of ≥99.5%, thereby expanding a new application field of the pressure swing adsorption oxygen production process.

Description

Technical Field

[0001] This invention relates to the field of oxygen production equipment technology, and more particularly to a high-temperature pressure swing adsorption (PSA) device for producing pure oxygen. Background Technology

[0002] Gas separation is a selective, large-scale gas preparation technique suitable for producing various industrial gases such as oxygen, nitrogen, and argon. Pressure swing adsorption (PSA) is a novel gas adsorption and separation technique for producing oxygen. This technique uses zeolite molecular sieves as adsorbents and utilizes the principle of pressure adsorption and pressure reduction desorption to adsorb and desorb nitrogen from the air, thereby separating oxygen. Pure oxygen is then obtained through repeated operations and concentration. Its advantages include: operation at room temperature and low pressure, low equipment investment, simple operation, low maintenance costs, and the ability to operate automatically and continuously.

[0003] Existing pressure swing adsorption (PSA) technology, limited by the performance of molecular sieve adsorbents and production principles, produces oxygen with a purity of 90%–96%, which cannot meet the medical pure oxygen standard (≥99.5%) or the industrial high-purity oxygen standard (≥99.9%). Therefore, the application scope of conventional PSA oxygen generation technology or equipment is somewhat limited. Summary of the Invention

[0004] To address the aforementioned technical problem of low oxygen purity obtained from existing pressure swing adsorption (PSA) technology, this invention provides a high-temperature PSA device for producing pure oxygen. This invention primarily utilizes the PSA principle, proposing a novel PSA process and equipment that overcomes the limitations on product oxygen purity, achieving an oxygen purity of ≥99.5%.

[0005] The technical means employed in this invention are as follows:

[0006] A high-temperature pressure swing adsorption (PSA) device for producing pure oxygen includes a filter. The inlet of the filter is connected to an air duct, the outlet of the filter is connected to the inlet of a blower, the outlet of the blower is connected to the inlet of an air buffer tank, the blower is connected to a frequency converter, the outlet of the air buffer tank is connected to a first inlet of an adsorption tower, the second inlet of the adsorption tower is connected to the outlet of an oxygen backflush tank, the outlet of the adsorption tower is connected to the inlet of a vacuum pump, the inlet of the oxygen backflush tank is connected to the outlet of the oxygen buffer tank, the oxygen buffer tank is connected to an oxygen analyzer or chromatograph and an oxygen flow meter, the outlet of the oxygen buffer tank is connected to an exhaust duct, and the outlet of the vacuum pump is connected to the exhaust duct.

[0007] Furthermore, the temperature range inside the adsorption tower is 400℃~1000℃.

[0008] Furthermore, the filling material inside the adsorption tower is an oxygen adsorption material, which is one or more porous ceramic materials, dense ceramic materials, metal or metal oxide materials, or a mixture of the above, and the applicable temperature range of the oxygen adsorption material is 400℃~1000℃.

[0009] Furthermore, the adsorption tower includes a first adsorption tower and a second adsorption tower.

[0010] Furthermore, the pipeline between the air buffer tank and the first adsorption tower is a first pipeline, and a first solenoid valve is installed on the first pipeline. The pipeline between the air buffer tank and the second adsorption tower is a second pipeline, and a second solenoid valve is installed on the second pipeline. The first pipeline and the second pipeline are connected by a third pipeline. The connection point between the third pipeline and the first pipeline is located between the first solenoid valve and the first adsorption tower. The connection point between the third pipeline and the second pipeline is located between the second solenoid valve and the second adsorption tower. The middle section of the third pipeline is connected to a fourth pipeline, and a third solenoid valve and a fourth solenoid valve are installed on the third pipeline. The third solenoid valve is located in the middle section of the third pipeline and connected to the first solenoid valve. Between the connection points of the three pipelines and the first pipeline, the fourth solenoid valve is located in the middle of the third pipeline and between the connection point of the third pipeline and the second pipeline. The first adsorption tower and the second adsorption tower are connected to the fourth pipeline. The fourth pipeline is sequentially equipped with a fifth solenoid valve, the connection point between the fourth pipeline and the first adsorption tower, a sixth solenoid valve, the connection point between the fourth pipeline and the oxygen backflush tank, a seventh solenoid valve, the connection point between the fourth pipeline and the second adsorption tower, and an eighth solenoid valve. The outlet pipeline is equipped with a ninth solenoid valve and a tenth solenoid valve. The connection point between the vacuum pump and the outlet pipeline is located between the ninth solenoid valve and the tenth solenoid valve. An eleventh solenoid valve is installed between the oxygen backflush tank and the oxygen buffer tank.

[0011] Furthermore, the adsorption tower is connected to a high-temperature heating element.

[0012] Furthermore, the high-temperature heating element is one or more of a metal heating wire, silicon carbide, and silicon molybdenum rod, and the high-temperature heating element has one or more structural forms such as an open tube type, an open box type, and a lifting type.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] This invention utilizes the principle of pressure swing adsorption (PSA) to propose a novel PSA process and equipment, breaking through the limitations of product oxygen purity and achieving an oxygen purity of ≥99.5%, thus expanding new application areas for PSA oxygen generation technology.

[0015] This invention utilizes atmospheric air as a raw material to achieve adsorption at normal or slightly positive pressure and desorption at negative pressure under high temperature conditions, without the need for other process coupling, to stably and continuously produce pure oxygen, with an oxygen recovery efficiency of ≥50%. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a diagram of the device of the present invention.

[0018] In the diagram: 1. Filter; 2. Blower; 3. Air buffer tank; 4. Vacuum pump; 5. Oxygen buffer tank; 6. Oxygen analyzer or chromatograph; 7. Oxygen flow meter; 8. Oxygen backflush tank; 9. High-temperature heating element; 10. First adsorption tower; 11. Second adsorption tower; 12. First solenoid valve; 13. Second solenoid valve; 14. Third solenoid valve; 15. Fourth solenoid valve; 16. Fifth solenoid valve; 17. Sixth solenoid valve; 18. Seventh solenoid valve; 19. Eighth solenoid valve; 20. Ninth solenoid valve; 21. Tenth solenoid valve; 22. Eleventh solenoid valve. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0023] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0024] like Figure 1 As shown, this invention provides a high-temperature pressure swing adsorption (PSA) device for producing pure oxygen, including a filter 1. The inlet of the filter is connected to an air duct, the outlet of the filter is connected to the inlet of a blower 2, the outlet of the blower is connected to the inlet of an air buffer tank 3, the blower is connected to a frequency converter, the outlet of the air buffer tank is connected to the first inlet of the adsorption tower, the second inlet of the adsorption tower is connected to the outlet of an oxygen backflush tank 8, the outlet of the adsorption tower is connected to the inlet of a vacuum pump 4, the inlet of the oxygen backflush tank is connected to the outlet of an oxygen buffer tank 5, the oxygen buffer tank is connected to an oxygen analyzer or chromatograph 6 and an oxygen flow meter 7, the outlet of the oxygen buffer tank is connected to an outlet pipe, and the outlet of the vacuum pump is connected to an outlet pipe. The adsorption tower is connected to a high-temperature heating element 9.

[0025] The temperature range inside the adsorption tower is 400℃ to 1000℃. The packing material inside the adsorption tower is a non-specific type of oxygen adsorption material, which can be one or more porous ceramic materials, dense ceramic materials, metal or metal oxide materials, or a mixture of the above materials. The applicable temperature for the packing material is 400℃ to 1000℃.

[0026] The high-temperature heating element is one or more of the following: metal heating wire, silicon carbide, silicon molybdenum rod, etc., and the heating element structure is one or more of the following: open tube type, open box type, lifting type, etc.

[0027] The adsorption process, cleaning process, backflushing process, and desorption process are all completed in a certain order within the adsorption tower, with each process taking 1 second to 3000 seconds.

[0028] The adsorption process is carried out under normal or slightly positive pressure conditions, with an absolute pressure value of 101 kPa to 200 kPa; the cleaning, backflushing, and desorption processes are carried out under negative pressure conditions, with an absolute pressure value of 0 kPa to 10 kPa.

[0029] The device contains two or more adsorption towers, each of which is an independent operating unit, enabling one or more adsorption towers to simultaneously perform adsorption, cleaning, backflushing, and desorption processes.

[0030] The adsorption tower includes a first adsorption tower 10 and a second adsorption tower 11. The pipeline between the air buffer tank and the first adsorption tower is a first pipeline, on which a first solenoid valve 12 is installed. The pipeline between the air buffer tank and the second adsorption tower is a second pipeline, on which a second solenoid valve 13 is installed. The first pipeline and the second pipeline are connected by a third pipeline. The connection point between the third pipeline and the first pipeline is located between the first solenoid valve and the first adsorption tower. The connection point between the third pipeline and the second pipeline is located between the second solenoid valve and the second adsorption tower. The middle section of the third pipeline is connected to a fourth pipeline, on which a third solenoid valve 14 and a fourth solenoid valve 15 are installed. The third solenoid valve is located in the middle section of the third pipeline and is connected to the first adsorption tower. Between the connection points of the pipelines, the fourth solenoid valve is located in the middle of the third pipeline and between the connection point of the third pipeline and the second pipeline. The first adsorption tower and the second adsorption tower are connected to the fourth pipeline. The fourth pipeline is sequentially equipped with the fifth solenoid valve 16, the connection point between the fourth pipeline and the first adsorption tower, the sixth solenoid valve 17, the connection point between the fourth pipeline and the oxygen backflush tank, the seventh solenoid valve 18, the connection point between the fourth pipeline and the second adsorption tower, and the eighth solenoid valve 19. The outlet pipeline is equipped with the ninth solenoid valve 20 and the tenth solenoid valve 21. The connection point between the vacuum pump and the outlet pipeline is located between the ninth solenoid valve and the tenth solenoid valve. The eleventh solenoid valve 22 is installed between the oxygen backflush tank and the oxygen buffer tank.

[0031] Air passes through a filter and enters a blower. The blower's frequency converter regulates the airflow. A fixed quantity of air enters an air buffer tank through the blower outlet. The air buffer tank outlet connects to an electromagnetic switching valve via an air pipeline. The electromagnetic valve controls the airflow direction, directing it into multiple different adsorption towers for atmospheric or slightly positive pressure adsorption. Vacuum pumps are connected to multiple adsorption towers for negative pressure cleaning and desorption processes. The desorbed pure oxygen enters an oxygen tank and a backflush tank. The backflush tank is connected to multiple adsorption towers for negative pressure backflush, and the backflush exhaust gas is vented by a vacuum pump. The oxygen tank outlet is connected to a gas flow meter, oxygen analyzer, or chromatograph for product measurement and purity analysis. Each adsorption tower can have two or more openings connected to air, a vacuum pump, and a backflush tank, respectively. Each adsorption tower is preheated and kept warm by high-temperature heating elements. The automatic control system provides automated program control of the blower, electromagnetic valves, vacuum pump, and heating elements.

[0032] Under stable conditions, the equipment continuously produces pure oxygen at a concentration of 96%–99.9%. The adsorption, cleaning, backflushing, and desorption processes are all carried out under high-temperature conditions, ranging from 400℃ to 1000℃.

[0033] The working process of this invention is as follows:

[0034] Set the temperature and heating rate, start the high-temperature heating element, and raise the adsorption tower to a specific temperature and maintain it at a constant temperature.

[0035] Air in the atmosphere is filtered through an air filter to remove dust and large particulate impurities; the frequency converter of the blower is adjusted to control the motor speed or output power, and after metering, a specific air volume is obtained to meet the oxygen supply requirements of the adsorption process.

[0036] After being metered, the air enters the air buffer tank. Once the air is mixed evenly, it enters the air pipeline at a constant speed. The direction of the gas flow is controlled by a solenoid valve in the pipeline.

[0037] Air enters the first adsorption tower through opening 1 at regular intervals to undergo oxygen adsorption. The high-nitrogen air, after some oxygen has been removed, is discharged through opening 2 of the first adsorption tower after being switched by a solenoid valve and subjected to heat exchange.

[0038] Meanwhile, after switching the solenoid valve in the pipeline, the second adsorption tower opening 1 is connected to the vacuum pump to carry out a timed negative pressure cleaning process, and the exhaust gas generated during cleaning is discharged into the air; then, after switching the solenoid valve again, the oxygen backflushing tank is connected to the second adsorption tower opening 2 to carry out a timed negative pressure backflushing process, and the exhaust gas generated during backflushing is discharged into the air.

[0039] After the second adsorption tower is cleaned and backflushed, timed negative pressure desorption is performed, and the desorbed oxygen enters the oxygen buffer tank.

[0040] After the two adsorption towers complete the above process, the first adsorption tower and the second adsorption tower are switched by the solenoid valve. At this time, the first adsorption tower is cleaned, backflushed and desorbed, while the second adsorption tower is adsorbed.

[0041] Pure oxygen can be continuously produced by repeating the above process in the first and second adsorption towers.

[0042] The oxygen buffer tank is connected to a flow meter, an oxygen analyzer, or a chromatograph to measure the amount of oxygen produced and analyze the purity of oxygen.

[0043] Example

[0044] The embodiment takes a dual-tower pressure swing adsorption device as an example, such as... Figure 1 As shown, the device is equipped with one blower (with a frequency converter), one vacuum pump, one mass flow meter, one gas chromatograph, two electric heating wire tube open-type furnaces, two adsorption towers (each adsorption tower has a volume of about 2L), one air buffer tank, one oxygen buffer tank, one oxygen backflush tank, 11 sets of solenoid valves, and one automatic control system.

[0045] In the example, the oxygen adsorbent in the adsorption tower is a metal oxide composite, and the composition of the adsorbent is shown in Table 1.

[0046] Turn on the high-temperature heating element, i.e., the electric heating wire tube type furnace, set the temperature to 450~650℃, and maintain an infinite constant temperature mode, with a heating rate of 10~15℃ / min.

[0047] Start the blower. Room temperature air enters the blower after being filtered to remove impurities. The flow rate is adjusted to 30L / min by the blower frequency converter, and the air enters the air buffer tank.

[0048] Open the first and fifth solenoid valves, and air enters the first adsorption tower through the gas pipeline and the first solenoid valve to carry out the adsorption process in the first adsorption tower. The adsorption time is 60 seconds, and the tail gas obtained after adsorption is discharged through the fifth solenoid valve.

[0049] During the adsorption process of the first adsorption tower, the fourth and ninth solenoid valves and the vacuum pump are simultaneously opened to perform the cleaning process of the second adsorption tower, with a cleaning time of 2-10 seconds. The seventh solenoid valve is opened and the fourth solenoid valve is closed, and the second adsorption tower is filled with pure oxygen under negative pressure, with a filling time of 1-4 seconds. The seventh solenoid valve is closed and the fourth solenoid valve is opened to perform the backflushing process of the second adsorption tower, with a backflushing time of 2-6 seconds. The ninth solenoid valve is closed and the tenth and eleventh solenoid valves are opened to perform the desorption process of the second adsorption tower and the filling of the oxygen backflushing tank with oxygen, with a time of 40-55 seconds.

[0050] After the first adsorption tower completes the adsorption process, it undergoes cleaning, backflushing, and desorption processes, while the second adsorption tower performs the adsorption process.

[0051] Open the second and eighth solenoid valves, and air enters the second adsorption tower through the gas pipeline and the second solenoid valve to carry out the adsorption process in the second adsorption tower. The adsorption time is 60 seconds, and the tail gas obtained after adsorption is discharged through the eighth solenoid valve.

[0052] During the adsorption process in the second adsorption tower, the third and ninth solenoid valves and the vacuum pump are simultaneously opened to perform the cleaning process of the first adsorption tower, with a cleaning time of 2-10 seconds. The sixth solenoid valve is opened and the third solenoid valve is closed, and the first adsorption tower is filled with pure oxygen under negative pressure, with a filling time of 1-4 seconds. The sixth solenoid valve is closed and the third solenoid valve is opened to perform the backflushing process of the first adsorption tower, with a backflushing time of 2-6 seconds. The ninth solenoid valve is closed and the tenth and eleventh solenoid valves are opened to perform the desorption process of the first adsorption tower and the filling of the oxygen backflushing tank with oxygen, with a time of 40-55 seconds.

[0053] The oxygen obtained from desorption is continuously transported to an oxygen buffer tank, where the oxygen pressure can reach 110-140 kPa. The oxygen flow rate is measured by a mass flow meter, and the oxygen purity is analyzed by a gas chromatograph.

[0054] The system automatically controls and repeats the above operation for 30 minutes, maintaining a stable oxygen production rate and oxygen purity ≥96%. After repeating the operation for 60 minutes, the oxygen purity remains ≥99.5%.

[0055] To better understand the present invention, the experimental conditions were verified in the embodiments, and the adsorption performance of the device is shown in Table 2.

[0056] Adsorption performance table 1

[0057]

[0058]

[0059] Adsorption performance table 2

[0060]

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 invention.

Claims

1. A high-temperature pressure swing adsorption (PSA) device for producing pure oxygen, characterized in that: The system includes a filter, the filter inlet of which is connected to an air duct, the filter outlet of which is connected to the inlet of a blower, the blower outlet of which is connected to the inlet of an air buffer tank, the blower being connected to a frequency converter, the air buffer tank outlet of which is connected to the first inlet of an adsorption tower, the adsorption tower second inlet of which is connected to the outlet of an oxygen backflush tank, the adsorption tower outlet of which is connected to the inlet of a vacuum pump, the oxygen backflush tank inlet of which is connected to the outlet of an oxygen buffer tank, the oxygen buffer tank being connected to an oxygen analyzer or chromatograph and an oxygen flow meter, the oxygen buffer tank outlet of which is connected to an exhaust duct, and the vacuum pump outlet of which is connected to an exhaust duct.

2. The high-temperature pressure swing adsorption (PSA) equipment for producing pure oxygen according to claim 1, characterized in that, The temperature range inside the adsorption tower is 400℃~1000℃.

3. The high-temperature pressure swing adsorption (PSA) equipment for producing pure oxygen according to claim 1, characterized in that, The adsorption tower is filled with an oxygen adsorption material, which is one or more porous ceramic materials, dense ceramic materials, metal or metal oxide materials, or a mixture of the above. The applicable temperature range of the oxygen adsorption material is 400℃~1000℃.

4. The high-temperature pressure swing adsorption (PSA) equipment for producing pure oxygen according to claim 1, characterized in that, The adsorption tower includes a first adsorption tower and a second adsorption tower.

5. The high-temperature pressure swing adsorption (PSA) equipment for producing pure oxygen according to claim 4, characterized in that, The pipeline between the air buffer tank and the first adsorption tower is the first pipeline, and a first solenoid valve is installed on the first pipeline. The pipeline between the air buffer tank and the second adsorption tower is the second pipeline, and a second solenoid valve is installed on the second pipeline. The first pipeline and the second pipeline are connected by a third pipeline. The connection point between the third pipeline and the first pipeline is located between the first solenoid valve and the first adsorption tower. The connection point between the third pipeline and the second pipeline is located between the second solenoid valve and the second adsorption tower. The middle section of the third pipeline is connected to a fourth pipeline, and a third solenoid valve and a fourth solenoid valve are installed on the third pipeline. The third solenoid valve is located in the middle section of the third pipeline. Between the connection point of the first pipeline and the connection point of the third pipeline and the second pipeline, the fourth solenoid valve is located in the middle of the third pipeline and between the third pipeline and the second pipeline. The first adsorption tower and the second adsorption tower are connected to the fourth pipeline. The fourth pipeline is sequentially equipped with a fifth solenoid valve, the connection point of the fourth pipeline and the first adsorption tower, a sixth solenoid valve, the connection point of the fourth pipeline and the oxygen backflush tank, a seventh solenoid valve, the connection point of the fourth pipeline and the second adsorption tower, and an eighth solenoid valve. The outlet pipeline is equipped with a ninth solenoid valve and a tenth solenoid valve. The connection point of the vacuum pump and the outlet pipeline is located between the ninth solenoid valve and the tenth solenoid valve. An eleventh solenoid valve is installed between the oxygen backflush tank and the oxygen buffer tank.

6. The high-temperature pressure swing adsorption (PSA) equipment for producing pure oxygen according to claim 1, characterized in that, The adsorption tower is connected to a high-temperature heating element.

7. The high-temperature pressure swing adsorption (PSA) equipment for producing pure oxygen according to claim 6, characterized in that, The high-temperature heating element is one or more of metal heating wire, silicon carbide, and silicon molybdenum rod, and the high-temperature heating element has one or more of the following structural forms: open tube type, open box type, and lifting type.

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