Novel pressure swing adsorption oxygen production three-tower device

Abstract

The utility model discloses a novel pressure swing adsorption oxygen production three-tower device which comprises an adsorption tower A, an adsorption tower B, an adsorption tower C and a pipeline, the air inlet ends of the adsorption tower A, the adsorption tower B and the adsorption tower C are all connected with an air blower and a vacuum pump, and the air outlet ends of the adsorption tower A, the adsorption tower B and the adsorption tower C are connected with an oxygen buffer tank. A first air inlet valve is arranged between the adsorption tower A and the air blower, a first vacuum valve is arranged between the adsorption tower A and the vacuum pump, a first air production valve is arranged between the adsorption tower A and the oxygen buffer tank, and the adsorption tower A is provided with a first pressure equalizing valve and a first gulp valve. According to the novel pressure swing adsorption oxygen production three-tower device, the problems that in a traditional process, gas is not produced during pressure equalizing of two tower processes, the oxygen amount and pressure fluctuation of products in the three-tower processes are smaller, the utilization rate of molecular sieves is higher, the energy consumption of produced gas can be reduced, the operation cost of equipment is reduced from the perspective of users, and the economic benefit is better are solved.

Description

Technical Field

[0001] This utility model relates to the field of oxygen production technology, specifically a novel pressure swing adsorption (PSA) oxygen production three-tower device. Background Technology

[0002] The mainstream pressure swing adsorption (PSA) process on the market is a two-tower process: air is pressurized to 49 kPa (G) by a Roots blower and then enters a VPSA oxygen enrichment unit consisting of two adsorption towers (one of which is always in adsorption mode). Under the selective adsorption of the adsorbent, oxygen enrichment with a purity of 70-93% is directly obtained. When the adsorbent is saturated with nitrogen, a Roots vacuum pump is used to draw a negative pressure to -53.3 kPa (G) to desorb and release the adsorbed nitrogen and moisture in the adsorbent. As the two adsorption towers alternately carry out the adsorption and desorption processes, oxygen is continuously generated.

[0003] The two-tower process is simple, but when pressure equalization is performed between the two towers, the system does not produce oxygen, which will cause fluctuations in the oxygen flow rate and pressure of the product (this problem needs to be solved by configuring an oxygen buffer tank with a sufficiently large volume); when the price of the main raw material (lithium carbonate) for molecular sieves rises, the investment cost of the equipment will increase significantly. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a novel three-tower pressure swing adsorption (PSA) oxygen generation device, which solves the problems of large fluctuations in product oxygen pressure and flow rate, low molecular sieve utilization, and inability to further reduce system energy consumption in the traditional two-tower PSA oxygen generation process.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: a novel pressure swing adsorption oxygen generation three-tower device, comprising adsorption tower A, adsorption tower B, adsorption tower C and pipelines, wherein the air inlet ends of adsorption tower A, adsorption tower B and adsorption tower C are all connected to a blower and a vacuum pump, and the air outlet ends of adsorption tower A, adsorption tower B and adsorption tower C are connected to an oxygen buffer tank.

[0006] A first air inlet valve is provided between the adsorption tower A and the blower; a first vacuum valve is provided between the adsorption tower A and the vacuum pump; a first gas generation valve is provided between the adsorption tower A and the oxygen buffer tank; and a first pressure equalization valve and a first gas replenishment valve are provided on the adsorption tower A.

[0007] A second air inlet valve is provided between the adsorption tower B and the blower; a second vacuum valve is provided between the adsorption tower B and the vacuum pump; a second gas generation valve is provided between the adsorption tower B and the oxygen buffer tank; and a second pressure equalization valve and a second gas replenishment valve are provided on the adsorption tower B.

[0008] A third air inlet valve is provided between the adsorption tower C and the blower; a third vacuum valve is provided between the adsorption tower C and the vacuum pump; a third gas generation valve is provided between the adsorption tower C and the oxygen buffer tank; and a third pressure equalization valve and a third gas replenishment valve are provided on the adsorption tower C.

[0009] Preferably, the blower is a Roots blower and the vacuum pump is a Roots vacuum pump.

[0010] Preferably, the booster pressure of the blower is set to 49 kPa, and the vacuum degree of the vacuum pump is set to -53.3 kPa.

[0011] Preferably, molecular sieves are installed inside adsorption tower A, adsorption tower B and adsorption tower C, and adsorption tower A, adsorption tower B and adsorption tower C are connected to each other through a first pressure equalization valve, a second pressure equalization valve and a third pressure equalization valve.

[0012] Preferably, the first intake valve, the second intake valve, the third intake valve, the first vacuum valve, the second vacuum valve, the third vacuum valve, the first gas generating valve, the second gas generating valve, the third gas generating valve, the first pressure equalizing valve, the second pressure equalizing valve, the third pressure equalizing valve, the first gas replenishing valve, the second gas replenishing valve, and the third gas replenishing valve are connected to a programmable PLC at their ends.

[0013] Preferably, the first, second, and third air supply valves are all equipped with silencers, and the first, second, and third air supply valves are connected to the atmosphere.

[0014] This invention provides a novel three-tower pressure swing adsorption (PSA) oxygen generation device. Compared with the prior art, it has the following advantages:

[0015] 1. This new type of pressure swing adsorption oxygen production three-tower device changes the traditional two-tower process where no gas is produced when equalizing pressure between the towers. The three-tower process produces oxygen with smaller fluctuations in both quantity and pressure.

[0016] 2. This novel pressure swing adsorption oxygen production three-tower device always produces gas from two towers at the same time. Compared with two towers, the utilization rate of molecular sieve is higher when the molecular sieve loading is the same.

[0017] 3. This new type of pressure swing adsorption oxygen production three-tower device opens the gas replenishment valve when the adsorption tower is under negative pressure, and realizes automatic gas replenishment through the pressure difference between the atmosphere and the adsorption tower, which can reduce the energy consumption of gas production.

[0018] 4. This new type of pressure swing adsorption oxygen production three-tower device has a significantly increased utilization rate of molecular sieves in the three-tower process, resulting in lower energy consumption in the oxygen production section compared to the traditional two-tower process. From the user's perspective, this reduces the operating cost of the equipment and provides better economic benefits. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the overall structure of this utility model.

[0020] In the diagram: 1. Adsorption tower A; 2. Adsorption tower B; 3. Adsorption tower C; 4. Pipeline; 5. Blower; 6. Vacuum pump; 7. Oxygen buffer tank; 8. First inlet valve; 9. First vacuum valve; 10. First gas production valve; 11. First pressure equalization valve; 12. First gas replenishment valve; 13. Second inlet valve; 14. Second vacuum valve; 15. Second gas production valve; 16. Second pressure equalization valve; 17. Second gas replenishment valve; 18. Third vacuum valve; 19. Third gas production valve; 20. Third pressure equalization valve; 21. Third gas replenishment valve; 22. Third inlet valve. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figure 1 This utility model provides a technical solution: a novel pressure swing adsorption (PSA) oxygen generation three-tower device, comprising adsorption tower A1, adsorption tower B2, adsorption tower C3, and pipeline 4. Molecular sieves are installed inside adsorption towers A1, B2, and C3. A blower 5 and a vacuum pump 6 are connected to the air inlet of each adsorption tower. The blower 5 is a Roots blower, and the vacuum pump 6 is a Roots vacuum pump. The Roots vacuum pump features fast start-up, low power consumption, low operating and maintenance costs, high pumping speed, and high efficiency. With high efficiency, the booster pressure of blower 5 is set to 49 kPa, and the vacuum degree of vacuum pump 6 is set to -53.3 kPa. The outlets of adsorption towers A1, B2, and C3 are connected to oxygen buffer tanks 7. Oxygen buffer tanks 7 can buffer oxygen, making the overall operation more stable. The raw material gas can be pressurized by blower 5 and then introduced into one of adsorption towers A1, B2, and C3. Then, 70-90% of the oxygen is discharged into oxygen buffer tanks 7.

[0023] A first inlet valve 8 is provided between adsorption tower A1 and blower 5; a first vacuum valve 9 is provided between adsorption tower A1 and vacuum pump 6; a first gas generation valve 10 is provided between adsorption tower A1 and oxygen buffer tank 7; and adsorption tower A1 is equipped with a first pressure equalization valve 11 and a first gas replenishment valve 12. A second inlet valve 13 is provided between adsorption tower B2 and blower 5; a second vacuum valve 14 is provided between adsorption tower B2 and vacuum pump 6; a second gas generation valve 15 is provided between adsorption tower B2 and oxygen buffer tank 7; and adsorption tower B2 is equipped with a second pressure equalization valve 16 and a second gas replenishment valve 17. A third inlet valve 22 is provided between adsorption tower C3 and blower 5; a third vacuum valve 18 is provided between adsorption tower C3 and vacuum pump 6; and a third gas generation valve 19 is provided between adsorption tower C3 and oxygen buffer tank 7. Adsorption tower C3 is equipped with a third pressure equalization valve 20 and a third gas replenishment valve 21. Silencers are installed on the first gas replenishment valve 12, the second gas replenishment valve 17, and the third gas replenishment valve 21. The sounder can effectively reduce noise, and the first gas replenishment valve 12, the second gas replenishment valve 17, and the third gas replenishment valve 21 are connected to the atmosphere. Adsorption towers A1, B2, and C3 are connected through the first pressure equalization valve 11, the second pressure equalization valve 16, and the third pressure equalization valve 20. The first gas inlet valve 8, the second gas inlet valve 13, the third gas inlet valve 22, the first vacuum valve 9, the second vacuum valve 14, the third vacuum valve 18, the first gas generation valve 10, the second gas generation valve 15, the third gas generation valve 19, the first pressure equalization valve 11, the second pressure equalization valve 16, the third pressure equalization valve 20, the first gas replenishment valve 12, the second gas replenishment valve 17, and the third gas replenishment valve 21 are connected to a programmable PLC. The above-mentioned gas inlet valve, vacuum valve, gas generation valve, pressure equalization valve, and gas replenishment valve are all programmable control valves, which can be controlled by the programmable PLC to open or close the programmable control valves, realize the automatic operation of the device, and the gas replenishment valve can automatically replenish gas, reducing the energy consumption of gas production.

[0024] Taking adsorption tower A1 as an example, the workflow is as follows:

[0025] 1. Adsorption process

[0026] After being pressurized by blower 5, the raw gas enters adsorption tower A1 from the bottom. After selective adsorption by the adsorbent, oxygen with a purity of 70-90% is directly obtained and discharged from the top of the tower into product oxygen buffer tank 7.

[0027] 2. Pressure equalization and reduction process

[0028] After the adsorption process is completed, the first inlet valve 8 and the first gas production valve 10 are closed, while the first equalizing valve 11 and the second equalizing valve 16 are opened. Since the pressure in adsorption tower A1 is higher than that in adsorption tower B2 at this time, under the action of the pressure difference, the gas in adsorption tower A1 flows into adsorption tower B2 along the adsorption direction. The oxygen content of this gas is also relatively high (but lower than the oxygen purity of the product). This process is not only a pressure reduction process, but also recovers the oxygen-rich gas in the dead space in the adsorption bed. When the pressures of adsorption tower A1 and adsorption tower B2 are basically close, the first equalizing valve 11 and the second equalizing valve 16 are closed, and the pressure equalization and pressure reduction process of adsorption tower A1 ends.

[0029] 3. Vacuuming process

[0030] After the pressure equalization and depressurization process is completed, the adsorption tower A1 immediately enters the vacuuming process. At this time, the first vacuum valve 9 is opened, and the gas in the adsorption tower A1 flows out against the adsorption direction. Under the action of pressure, the gas is forcibly extracted by the vacuum pump 6. At this time, the nitrogen adsorbed on the adsorbent is gradually desorbed. All the gas in the adsorption tower A1 is extracted by the vacuum pump 6 until the impurities in the adsorbent are fully desorbed. Then the first vacuum valve 9 is closed, and the vacuuming process ends.

[0031] 4. Pressure equalization and boosting process

[0032] This process corresponds to the pressure equalization and depressurization process. After the vacuuming process of adsorption tower A1 is completed, the first pressure equalization valve 11 and the second pressure equalization valve 16 are opened. Since the gas pressure in adsorption tower B2 is higher than that in adsorption tower A1 at this time, under the action of the pressure difference, the gas in adsorption tower B2 flows into adsorption tower A1. At the same time, the pressure in adsorption tower A1 increases. After the gas comes into full contact with the adsorbent, the nitrogen in it is fully adsorbed by the adsorbent. When the pressures of adsorption tower A1 and adsorption tower B2 are basically close, the pressure equalization is closed, and the pressure equalization and depressurization process of adsorption tower A1 ends.

[0033] 5. Product gas pressurization process

[0034] After the pressure equalization and pressurization process is completed, the first gas production valve 10 is opened to a certain degree. Since the gas pressure in the tower is still low at this time (lower than the product gas pressure), the product oxygen enters the adsorption tower A1 due to the pressure. It has two functions: one is to use the product gas to blow the nitrogen gas that has not been in contact with the adsorbent in the upper head of the adsorption tower into the adsorbent layer and be adsorbed by contact with the adsorbent; the other function is to increase the pressure in the adsorption tower A1 to reach the adsorption pressure. At this time, the product gas pressurization process of the adsorption tower A1 ends.

[0035] After this process, the adsorption tower completes the entire regeneration process and is ready for the next adsorption cycle.

[0036] By alternating between adsorption towers A1, B2, and C3, a continuous product of oxygen can be obtained (in sequence, combinations of A+B, B+C, and C+A can be formed).

[0037] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

Claims

1. A novel three-column pressure swing adsorption oxygen generation plant, characterized in that: It includes adsorption tower A (1), adsorption tower B (2), adsorption tower C (3) and pipeline (4), the air inlet end of adsorption tower A (1), adsorption tower B (2) and adsorption tower C (3) are connected with air blower (5) and vacuum pump (6), the air outlet end of adsorption tower A (1), adsorption tower B (2) and adsorption tower C (3) is connected with oxygen buffer tank (7); The first air inlet valve (8) is arranged between the adsorption tower A (1) and the air blower (5), the first vacuum valve (9) is arranged between the adsorption tower A (1) and the vacuum pump (6), the first gas production valve (10) is arranged between the adsorption tower A (1) and the oxygen buffer tank (7), and the first equalizing valve (11) and the first air supplement valve (12) are arranged on the adsorption tower A (1); The second air inlet valve (13) is arranged between the adsorption tower B (2) and the air blower (5), the second vacuum valve (14) is arranged between the adsorption tower B (2) and the vacuum pump (6), the second gas production valve (15) is arranged between the adsorption tower B (2) and the oxygen buffer tank (7), the second equalizing valve (16) and the second air supplement valve (17) are arranged on the adsorption tower B (2); The third air inlet valve (22) is arranged between the adsorption tower C (3) and the air blower (5), the third vacuum valve (18) is arranged between the adsorption tower C (3) and the vacuum pump (6), the third gas production valve (19) is arranged between the adsorption tower C (3) and the oxygen buffer tank (7), the third equalizing valve (20) and the third air supplement valve (21) are arranged on the adsorption tower C (3).

2. A novel three-column pressure swing adsorption oxygen generation plant as claimed in claim 1, wherein: The air blower (5) is arranged as a Roots air blower, and the vacuum pump (6) is arranged as a Roots vacuum pump.

3. A novel three-column pressure swing adsorption oxygen generation plant as claimed in claim 1, wherein: The boost air pressure of the air blower (5) is set to 49kpa, and the vacuum degree of the vacuum pump (6) is set to-53.3kpa.

4. A novel three-column pressure swing adsorption oxygen generation plant as claimed in claim 1, wherein: Molecular sieves are installed in the adsorption tower A (1), the adsorption tower B (2) and the adsorption tower C (3), and the adsorption tower A (1), the adsorption tower B (2) and the adsorption tower C (3) are connected in communication through the first equalizing valve (11), the second equalizing valve (16) and the third equalizing valve (20).

5. A novel three-column pressure swing adsorption oxygen generation plant as claimed in claim 1, wherein: The first air inlet valve (8), the second air inlet valve (13), the third air inlet valve (22), the first vacuum valve (9), the second vacuum valve (14), the third vacuum valve (18), the first gas production valve (10), the second gas production valve (15), the third gas production valve (19), the first equalizing valve (11), the second equalizing valve (16), the third equalizing valve (20), the first air supplement valve (12), the second air supplement valve (17) and the third air supplement valve (21) are connected with programmable PLC at the end.

6. A novel three-column pressure swing adsorption oxygen generation plant as claimed in claim 1, wherein: Silencers are installed on the first air supplement valve (12), the second air supplement valve (17) and the third air supplement valve (21), and the first air supplement valve (12), the second air supplement valve (17) and the third air supplement valve (21) are connected with the atmosphere.

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