Pressure swing adsorption air separation oxygen generation system and operation method

Abstract

The invention relates to a pressure swing adsorption air separation oxygen generation system and an operation method, the pressure swing adsorption air separation oxygen generation system comprises an air compressor, a first adsorption tower and a second adsorption tower; 1, the first adsorption tower and the second adsorption tower alternately perform adsorption and desorption operations, so that oxygen with the concentration not meeting the requirement can flow back into the desorption-completed adsorption tower again, and waste caused by emptying is avoided; 2, the oxygen concentration of the oxygen which does not meet the requirement is far greater than that of the air, so that the oxygen enters the adsorption tower and is adsorbed by the oxygen production adsorbent again, and the oxygen concentration can be effectively improved; and 3, after the desorption of the adsorption tower is completed, the adsorption tower is pressurized through the other adsorption tower and the oxygen buffer tank, so that the adsorption tower can quickly enter a stable adsorption working state, and the production efficiency can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of air separation and oxygen production, and in particular to a pressure swing adsorption air separation and oxygen production system and an operation method. Background Art

[0002] Pressure swing adsorption (PSA) has been widely used in gas separation and purification, especially in small and medium-scale air separation and oxygen production. It is a relatively economical method to obtain high-purity small and medium-yield oxygen, mainly used in medical treatment and home oxygen therapy.

[0003] The steps of pressurization, adsorption, pressure reduction and desorption, pressure equalization, backwashing and cleaning are the basic steps of the PSA cycle. Among them, the cycle switching time of the step time combination is the key process parameter affecting the performance of the PSA process.

[0004] In order to realize the continuous alternating operation of the PSA adsorption bed cycle, the adsorption process time (including the time of the pressurization and adsorption steps) during the cycle is usually equal to the desorption process time (including the time of the depressurization desorption and backwashing steps). The adsorption time depends on the effective filling height of the adsorbent in the oxygen production process, the feed rate and the minimum target product concentration. It is usually longer due to the large height-to-diameter ratio of the adsorption bed, generally 5 to 100 seconds. It usually takes nearly 50 consecutive adsorption and desorption cycles for the PSA cycle to reach a stable state. Therefore, the startup time of the PSA air separation oxygen production system is generally 5 to 50 minutes. For medical oxygen supply systems and home oxygen therapy, the relevant national standards have strict requirements on the oxygen purity in the product gas of the PSA system, generally requiring the oxygen purity to be not less than 90%. Therefore, when the oxygen purity of the product gas obtained by the actual PSA oxygen production system is lower than 90%, it can only be vented and wasted, and the system startup time is very long, and the oxygen production efficiency is low. Summary of the invention

[0005] In order to solve the technical problems in the background technology, the present invention discloses a pressure swing adsorption air separation oxygen production system and an operation method.

[0006] The present invention provides a pressure swing adsorption air separation oxygen production system, comprising an air compressor, a first adsorption tower and a second adsorption tower;

[0007] The inlets of the first adsorption tower and the second adsorption tower are respectively connected to the first air inlet pipe and the second air inlet pipe, and the outlet of the air compressor is connected to the inlet of the first air inlet pipe and the inlet of the second air inlet pipe in parallel;

[0008] The outlets of the first adsorption tower and the second adsorption tower are connected to the first outlet pipe and the second outlet pipe respectively. The first outlet pipe and the outlet of the second outlet pipe merge and are connected to the inlet of the output pipe, and the output pipe outputs oxygen. A tail control valve is arranged on the output pipe.

[0009] The first air intake pipe is provided with a first air intake valve, and the second air intake pipe is provided with a second air intake valve;

[0010] The inlets of the first adsorption tower and the second adsorption tower are also respectively connected to a first desorption valve and a second desorption valve communicating with the outside;

[0011] A first connecting pipe is led out from the middle of the first air outlet pipe, and an outer end of the first connecting pipe is connected to one end of the first air outlet valve;

[0012] A second connecting pipe is led out from the middle position of the second air outlet pipe, and an outer end of the second connecting pipe is connected to one end of the second air outlet valve;

[0013] The other ends of the first air outlet valve and the second air outlet valve are connected via a third connecting pipe;

[0014] The third connecting pipe leads to a fourth connecting pipe, and the other end of the fourth connecting pipe is connected in parallel with the inlet of the first air intake pipe and the inlet of the second air intake pipe; the fourth connecting pipe is provided with a first angle seat valve;

[0015] A return pipe is also led out from the middle of the output pipe, and the other end of the return pipe is connected to the third connecting pipe; a backflush control valve is arranged on the return pipe;

[0016] The first adsorption tower and the second adsorption tower alternately adsorb and desorb;

[0017] When the first adsorption tower is performing adsorption and the second adsorption tower is performing desorption, if the oxygen concentration in the output pipe is unqualified, the unqualified oxygen enters the second adsorption tower through the reflux pipe. After the desorption of the second adsorption tower is completed, the outlet of the first adsorption tower is connected to the outlet of the second adsorption tower, and the outlet of the first adsorption tower is connected to the inlet of the second adsorption tower in sequence.

[0018] The beneficial effects of the above arrangement are: 1. The first adsorption tower and the second adsorption tower alternately perform adsorption and desorption operations, so that oxygen whose concentration does not meet the requirements can flow back into the adsorption tower where desorption is completed, thereby avoiding waste caused by venting; 2. The oxygen whose concentration does not meet the requirements has an oxygen concentration much greater than that of air, so these oxygens enter the adsorption tower and are adsorbed by the oxygen-generating adsorbent again, which can effectively increase the oxygen concentration; 3. When the desorption of the adsorption tower is completed, it is pressurized by another adsorption tower and pressurized by the oxygen buffer tank, so that the adsorption tower can quickly enter a stable adsorption working state, thereby improving production efficiency.

[0019] Furthermore, the outlet of the air compressor is connected to the cold dryer, the air buffer tank and the main valve in sequence through pipelines; the outlet of the main valve is connected to the inlet of the first air intake pipe and the inlet of the second air intake pipe in parallel.

[0020] Furthermore, the outlet of the output pipe is connected to an oxygen buffer tank; the outlet of the oxygen buffer tank is connected to an oxygen collecting pipe and a reflux pipe in parallel; an oxygen concentration detector and a second angle seat valve are provided on the oxygen collecting pipe.

[0021] Furthermore, a charging pipe is led out from the oxygen collection pipe between the outlet of the oxygen buffer tank and the second angle seat valve, and the other end of the charging pipe is connected to the reflux pipe, and the connection point is located at the outlet of the backwash control valve; a charging control valve is provided on the charging pipe.

[0022] The present invention also provides an operating method of a pressure swing adsorption air separation oxygen production system, comprising the following steps:

[0023] Before the system starts working, all equipment and valves are in the closed state; when starting working, open the air compressor, cold dryer and main valve first;

[0024] S1, open the first air inlet valve to pressurize the first adsorption tower. When the pressure of the first adsorption tower rises to the set pressure, open the tail control valve to allow the first adsorption tower to inlet air for adsorption;

[0025] Open the backflush control valve, the second outlet valve and the second desorption valve to allow the oxygen in the oxygen buffer tank to enter the second adsorption tower and exhaust the desorbed nitrogen;

[0026] S2, the cavity between the oxygen-generating adsorbent and the outlet in the adsorption tower is set as an oxygen cavity, and the cavity between the oxygen-generating adsorbent and the inlet is set as an air cavity;

[0027] The second desorption valve, the back-blowing control valve, the first air inlet valve and the tail control valve are closed, and the first air outlet valve and the second air outlet valve are opened, so that the outlets of the first adsorption tower and the second adsorption tower are connected, and the oxygen chamber of the first adsorption tower pressurizes the oxygen chamber of the second adsorption tower;

[0028] S3, closing the second air outlet valve, opening the first angle seat valve and the second air inlet valve, so that the outlet of the first adsorption tower is connected to the inlet of the second adsorption tower, and the oxygen chamber of the first adsorption tower pressurizes the air chamber of the second adsorption tower;

[0029] S4, closing the first angle seat valve and the second air inlet valve, opening the second air outlet valve and the pressure control valve, so that the oxygen in the oxygen buffer tank pressurizes the second adsorption tower;

[0030] Close the first gas outlet valve and the first gas inlet valve, and open the first desorption valve to reduce the pressure of the first adsorption tower for desorption;

[0031] S5, closing the second air outlet valve and the pressure control valve, and opening the second air inlet valve to allow air to pressurize the second adsorption tower;

[0032] S6, opening the backflush control valve and the first air outlet valve, so that the oxygen in the oxygen buffer tank enters the first adsorption tower, and the desorbed nitrogen is exhausted;

[0033] Open the second air inlet valve and the tail control valve to allow air to enter the second adsorption tower for adsorption;

[0034] S7, close the first desorption valve and the back-blowing control valve, and open the first gas outlet valve;

[0035] Close the second air inlet valve and the tail control valve, and open the second air outlet valve;

[0036] The oxygen chamber of the second adsorption tower pressurizes the oxygen chamber of the first adsorption tower;

[0037] S8, closing the first air outlet valve, opening the first air inlet valve and the first angle seat valve, so that the oxygen chamber of the second adsorption tower pressurizes the air chamber of the first adsorption tower;

[0038] S9, closing the first air inlet valve, the second air outlet valve and the first angle seat valve;

[0039] Open the charging control valve, the first gas outlet valve and the second desorption valve;

[0040] The oxygen in the oxygen buffer tank pressurizes the first adsorption tower, so that the second adsorption tower depressurizes and desorbs;

[0041] S10, closing the first air outlet valve and the charging control valve;

[0042] S11, looping steps S1-S10 until the oxygen concentration detected by the oxygen concentration detector meets the requirements, opening the second angle seat valve to collect oxygen; assuming that the oxygen concentration generated during the intake adsorption of the first adsorption tower meets the requirements, the second adsorption tower is in a depressurized desorption state at this time;

[0043] S12, opening the backflush control valve, the second air outlet valve and the second desorption valve, so that the oxygen in the oxygen buffer tank enters the second adsorption tower, and the desorbed nitrogen is exhausted;

[0044] S13, closing the second desorption valve, the back-blowing control valve, the first air inlet valve and the tail control valve, opening the first air outlet valve and the second air outlet valve, so that the outlets of the first adsorption tower and the second adsorption tower are connected, and the oxygen chamber of the first adsorption tower pressurizes the oxygen chamber of the second adsorption tower;

[0045] S14, closing the second air outlet valve, opening the first angle seat valve and the second air inlet valve, so that the outlet of the first adsorption tower is connected to the inlet of the second adsorption tower, and the oxygen chamber of the first adsorption tower pressurizes the air chamber of the second adsorption tower;

[0046] S15, closing the first air outlet valve and the first angle seat valve;

[0047] Open the first desorption valve and the second intake valve;

[0048] The first adsorption tower is depressurized to desorb, and the second adsorption tower is pressurized with compressed air;

[0049] S16, opening the backflush control valve and the first air outlet valve, so that the oxygen in the oxygen buffer tank enters the first adsorption tower, and the desorbed nitrogen is exhausted;

[0050] At the same time, when the pressure in the second adsorption tower reaches the set value, the tail control valve is opened, and the second adsorption tower is fed with air for adsorption;

[0051] S17, closing the backflush control valve, the first desorption valve, the second air intake valve and the tail control valve;

[0052] Opening the first gas outlet valve and the second gas outlet valve, so that the oxygen chamber of the second adsorption tower pressurizes the oxygen chamber of the first adsorption tower;

[0053] S18, closing the first air outlet valve, opening the first air inlet valve and the first angle seat valve, so that the oxygen chamber of the second adsorption tower pressurizes the air chamber of the first adsorption tower;

[0054] S19, opening the first air inlet valve and the second desorption valve, and closing the first angle seat valve, so that the air pressurizes the first adsorption tower, and the second adsorption tower depressurizes and desorbs;

[0055] S20, looping steps S12-S19, continuously producing oxygen with a concentration that meets the requirements.

[0056] The beneficial effects of the present invention are: 1. The first adsorption tower and the second adsorption tower alternately perform adsorption and desorption operations, so that oxygen whose concentration does not meet the requirements can flow back into the adsorption tower where desorption is completed, thereby avoiding waste caused by emptying; 2. The oxygen whose concentration does not meet the requirements has an oxygen concentration much greater than that of air, so the oxygen enters the adsorption tower and is adsorbed by the oxygen-generating adsorbent again, which can effectively increase the oxygen concentration; 3. When the desorption of the adsorption tower is completed, it is pressurized by another adsorption tower and pressurized by an oxygen buffer tank, so that the adsorption tower can quickly enter a stable adsorption working state, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0058] Figure 1 It is a schematic diagram of the structure of the present invention;

[0059] In the figure: 1. air compressor; 2. first adsorption tower; 3. second adsorption tower; 4. first air inlet pipe; 5. second air inlet pipe; 6. first air outlet pipe; 7. second air outlet pipe; 8. output pipe; 9. first air inlet valve; 10. second air inlet valve; 11. first desorption valve; 12. second desorption valve; 13. first air outlet valve; 14. second air outlet valve; 15. third connecting pipe; 16. fourth connecting pipe; 17. first angle seat valve; 18. reflux pipe; 19. backflush control valve; 20. cold dryer; 21. air buffer tank; 22. main valve; 23. oxygen buffer tank; 24. oxygen collecting pipe; 25. oxygen concentration detector; 26. second angle seat valve; 27. charging pipe; 28. charging control valve; 29. ​​tail control valve; 61. first connecting pipe; 71. second connecting pipe. DETAILED DESCRIPTION

[0060] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0061] Embodiment 1:

[0062] like Figure 1 As shown, the present invention discloses a pressure swing adsorption air separation oxygen production system, comprising an air compressor 1, a first adsorption tower 2 and a second adsorption tower 3. The first adsorption tower 2 and the second adsorption tower 3 are provided with oxygen production adsorbents to perform alternating adsorption and desorption. The inlets of the first adsorption tower 2 and the second adsorption tower 3 are respectively connected to the first air inlet pipe 4 and the second air inlet pipe 5, the first air inlet pipe 4 is provided with a first air inlet valve 9, and the second air inlet pipe 5 is provided with a second air inlet valve 10. The outlet of the air compressor 1 is sequentially connected to a cold dryer 20, an air buffer tank 21 and a main valve 22 through pipelines, and the outlet of the main valve 22 is connected to the inlet of the first air inlet pipe 4 and the inlet of the second air inlet pipe 5 in a parallel manner. The cold dryer 20 is used to filter water vapor and impurities in the air, and the air buffer tank 21 is used for air buffering, so that the pressure of the air flowing into the adsorption tower remains stable.

[0063] The outlets of the first adsorption tower 2 and the second adsorption tower 3 are connected to the first outlet pipe 6 and the second outlet pipe 7 respectively. The first outlet pipe 6 and the outlet of the second outlet pipe 7 converge and are connected to the inlet of the output pipe 8. The output pipe 8 is provided with a tail control valve 29. The outlet of the output pipe 8 is connected to the inlet of the oxygen buffer tank 23. The outlet of the oxygen buffer tank 23 is connected to the oxygen collecting pipe 24. The middle position of the oxygen collecting pipe 24 is installed with an oxygen concentration detector 25 and a second angle seat valve 26. The outlet of the oxygen collecting pipe 24 is connected to the inlet of the oxygen compressor for collecting oxygen. The oxygen concentration detector 25 is located near the outlet of the oxygen buffer tank 23. The oxygen buffer tank 23 is used for oxygen buffering so that the pressure of oxygen flowing out of the oxygen buffer tank 23 remains stable.

[0064] The inlets of the first adsorption tower 2 and the second adsorption tower 3 are respectively connected with a first desorption valve 11 and a second desorption valve 12 communicating with the outside.

[0065] A first connecting pipe 61 is led out from the middle of the first air outlet pipe 6, and the outer end of the first connecting pipe 61 is connected to one end of the first air outlet valve 13; a second connecting pipe 71 is led out from the middle of the second air outlet pipe 7, and the outer end of the second connecting pipe 71 is connected to one end of the second air outlet valve 14; the other ends of the first air outlet valve 13 and the second air outlet valve 14 are connected through a third connecting pipe 15. The third connecting pipe 15 leads out to a fourth connecting pipe 16, and the other end of the fourth connecting pipe 16 is connected to the inlet of the first air inlet pipe 4 and the inlet of the second air inlet pipe 5 in parallel; a first angle seat valve 17 is provided on the fourth connecting pipe 16.

[0066] The outlet of the oxygen buffer tank 23 is also connected to a reflux pipe 18 in parallel with the oxygen collecting pipe 24, and the other end of the reflux pipe 18 is connected to the third connecting pipe 15; a backflush control valve 19 is provided on the reflux pipe 18. The opening of the backflush control valve 19 is fixedly adjusted to 5-45%, which is used to increase the flow rate of the oxygen in the oxygen buffer tank 23 entering the adsorption tower, so that the desorbed nitrogen in the adsorption tower is quickly discharged.

[0067] The oxygen collecting pipe 24 is located between the outlet of the oxygen buffer tank 23 and the second angle seat valve 26, and a pressure charging pipe 27 is led out. The other end of the pressure charging pipe 27 is connected to the reflux pipe 18, and the connection point is located at the outlet of the back-blowing control valve 19. A pressure charging control valve 28 is arranged on the pressure charging pipe 27. When the pressure charging control valve 28 is opened, the oxygen in the oxygen buffer tank 23 can be quickly charged into the adsorption tower, so as to quickly increase the gas pressure in the adsorption tower, so that the adsorption tower can quickly perform adsorption work.

[0068] Compared with the prior art, the beneficial effects of the present invention are: 1. The first adsorption tower 2 and the second adsorption tower 3 alternately perform adsorption and desorption operations, so that oxygen whose concentration does not meet the requirements can flow back into the adsorption tower where desorption is completed, thereby avoiding waste caused by emptying; 2. The oxygen whose concentration does not meet the requirements has an oxygen concentration much greater than that of air, so the oxygen enters the adsorption tower and is adsorbed by the oxygen-generating adsorbent again, which can effectively increase the oxygen concentration. After 3-4 cycles, oxygen that meets the concentration requirements can be produced, thereby improving the oxygen production efficiency.

[0069] Embodiment 2:

[0070] The present invention also discloses an operation method of a pressure swing adsorption air separation oxygen production system, which adopts a pressure swing adsorption air separation oxygen production system of embodiment 1, comprising the following steps:

[0071] Before the system starts working, all equipment and valves are in the closed state; when starting working, open the air compressor 1, cold dryer 20 and main valve 22;

[0072] S1, open the first air inlet valve 9 to pressurize the first adsorption tower 2. When the pressure of the first adsorption tower 2 rises to the set pressure, open the tail control valve 29 to allow the first adsorption tower 2 to inlet air for adsorption;

[0073] Open the backflush control valve 19, the second gas outlet valve 14 and the second desorption valve 12, so that the oxygen in the oxygen buffer tank 23 enters the second adsorption tower 3, and the desorbed nitrogen is exhausted;

[0074] S2, the cavity between the oxygen-generating adsorbent and the outlet in the adsorption tower is set as an oxygen cavity, and the cavity between the oxygen-generating adsorbent and the inlet is set as an air cavity;

[0075] The second desorption valve 12, the back-blowing control valve 19, the first air inlet valve 9 and the tail control valve 29 are closed, and the first air outlet valve 13 and the second air outlet valve 14 are opened, so that the outlets of the first adsorption tower 2 and the second adsorption tower 3 are connected, and the oxygen chamber of the first adsorption tower 2 pressurizes the oxygen chamber of the second adsorption tower 3;

[0076] S3, close the second air outlet valve 14, open the first angle seat valve 17 and the second air inlet valve 10, so that the outlet of the first adsorption tower 2 and the inlet of the second adsorption tower 3 are connected, and the oxygen chamber of the first adsorption tower 2 pressurizes the air chamber of the second adsorption tower 3;

[0077] S4, close the first angle seat valve 17 and the second air inlet valve 10, open the second air outlet valve 14 and the pressure control valve 28, so that the oxygen in the oxygen buffer tank 23 pressurizes the second adsorption tower 3;

[0078] Close the first gas outlet valve 13 and the first gas inlet valve 9, and open the first desorption valve 11 to reduce the pressure of the first adsorption tower 2 for desorption;

[0079] S5, close the second air outlet valve 14 and the pressure control valve 28, open the second air inlet valve 10, so that the air pressurizes the second adsorption tower 3;

[0080] S6, open the backflush control valve 19 and the first gas outlet valve 13, so that the oxygen in the oxygen buffer tank 23 enters the first adsorption tower 2, and the desorbed nitrogen is exhausted;

[0081] Open the second air inlet valve 10 and the tail control valve 29 to allow the second adsorption tower 3 to absorb air;

[0082] S7, close the first desorption valve 11 and the back-blowing control valve 19, and open the first gas outlet valve 13;

[0083] Close the second air inlet valve 10 and the tail control valve 29, and open the second air outlet valve 14;

[0084] The oxygen chamber of the second adsorption tower 3 pressurizes the oxygen chamber of the first adsorption tower 2;

[0085] S8, close the first air outlet valve 13, open the first air inlet valve 9 and the first angle seat valve 17, so that the oxygen chamber of the second adsorption tower 3 pressurizes the air chamber of the first adsorption tower 2;

[0086] S9, close the first air inlet valve 9, the second air outlet valve 14 and the first angle seat valve 17;

[0087] Open the charging control valve 28, the first gas outlet valve 13 and the second desorption valve 12;

[0088] The oxygen in the oxygen buffer tank 23 pressurizes the first adsorption tower 2, so that the second adsorption tower 3 is depressurized and desorbed;

[0089] S10, closing the first gas outlet valve 13 and the charging control valve 28;

[0090] S11, looping steps S1-S10, until the oxygen concentration detected by the oxygen concentration detector 25 meets the requirements, opening the second angle seat valve 26 to collect oxygen; assuming that the oxygen concentration generated during the intake adsorption of the first adsorption tower 2 meets the requirements, the second adsorption tower 3 is in a decompression desorption state;

[0091] S12, opening the backflush control valve 19, the second gas outlet valve 14 and the second desorption valve 12, so that the oxygen in the oxygen buffer tank 23 enters the second adsorption tower 3, and the desorbed nitrogen is exhausted;

[0092] S13, close the second desorption valve 12, the back-blowing control valve 19, the first air inlet valve 9 and the tail control valve 29, open the first air outlet valve 13 and the second air outlet valve 14, so that the outlets of the first adsorption tower 2 and the second adsorption tower 3 are connected, and the oxygen chamber of the first adsorption tower 2 pressurizes the oxygen chamber of the second adsorption tower 3;

[0093] S14, close the second air outlet valve 14, open the first angle seat valve 17 and the second air inlet valve 10, so that the outlet of the first adsorption tower 2 and the inlet of the second adsorption tower 3 are connected, and the oxygen chamber of the first adsorption tower 2 pressurizes the air chamber of the second adsorption tower 3;

[0094] S15, closing the first air outlet valve 13 and the first angle seat valve 17;

[0095] Open the first desorption valve 11 and the second intake valve 10;

[0096] The first adsorption tower 2 is depressurized to desorb, and the compressed air is used to pressurize the second adsorption tower 3;

[0097] S16, opening the backflush control valve 19 and the first gas outlet valve 13, so that the oxygen in the oxygen buffer tank 23 enters the first adsorption tower 2, and the desorbed nitrogen is exhausted;

[0098] At the same time, when the pressure in the second adsorption tower 3 reaches the set value, the tail control valve 29 is opened, and the second adsorption tower 3 is fed with air for adsorption;

[0099] S17, close the blowback control valve 19, the first desorption valve 11, the second intake valve 10 and the tail control valve 29;

[0100] Open the first gas outlet valve 13 and the second gas outlet valve 14 so that the oxygen chamber of the second adsorption tower 3 pressurizes the oxygen chamber of the first adsorption tower 2;

[0101] S18, close the first air outlet valve 13, open the first air inlet valve 9 and the first angle seat valve 17, so that the oxygen chamber of the second adsorption tower 3 pressurizes the air chamber of the first adsorption tower 2;

[0102] S19, open the first air inlet valve 9 and the second desorption valve 12, and close the first angle seat valve 17, so that the air pressurizes the first adsorption tower 2, and the second adsorption tower 3 depressurizes and desorbs;

[0103] S20, looping steps S12-S19, continuously producing oxygen with a concentration that meets the requirements.

[0104] Compared with the prior art, the beneficial effects of this embodiment are: 1. The first adsorption tower 2 and the second adsorption tower 3 alternately perform adsorption and desorption operations, so that the oxygen whose concentration does not meet the requirements can flow back into the adsorption tower where desorption is completed, avoiding waste caused by venting; 2. The oxygen whose concentration does not meet the requirements has an oxygen concentration much greater than that of air. Therefore, these oxygens enter the adsorption tower and are adsorbed by the oxygen-generating adsorbent again, which can effectively increase the oxygen concentration. After 3-4 cycles, oxygen that meets the concentration requirements can be produced, thereby improving the oxygen production efficiency; 3. When the adsorption tower is desorbed, it is pressurized by another adsorption tower and pressurized by the oxygen buffer tank 23, so that the adsorption tower can quickly enter a stable adsorption working state, thereby improving production efficiency.

[0105] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A pressure swing adsorption air separation oxygen production system, characterized in that: It comprises an air compressor (1), a first adsorption tower (2) and a second adsorption tower (3); The inlets of the first adsorption tower (2) and the second adsorption tower (3) are respectively connected to a first air intake pipe (4) and a second air intake pipe (5); the outlet of the air compressor (1) is connected in parallel to the inlet of the first air intake pipe (4) and the inlet of the second air intake pipe (5); The outlets of the first adsorption tower (2) and the second adsorption tower (3) are respectively connected to a first outlet pipe (6) and a second outlet pipe (7); the first outlet pipe (6) and the outlet of the second outlet pipe (7) merge and are connected to an inlet of an output pipe (8); the output pipe (8) outputs oxygen; a tail control valve (29) is provided on the output pipe (8); The first air intake pipe (4) is provided with a first air intake valve (9), and the second air intake pipe (5) is provided with a second air intake valve (10); The inlets of the first adsorption tower (2) and the second adsorption tower (3) are respectively connected to a first desorption valve (11) and a second desorption valve (12) which are in communication with the outside; A first connecting pipe (61) is led out from the middle position of the first air outlet pipe (6), and the outer end of the first connecting pipe (61) is connected to one end of a first air outlet valve (13); A second connecting pipe (71) is led out from the middle position of the second air outlet pipe (7), and the outer end of the second connecting pipe (71) is connected to one end of a second air outlet valve (14); The other ends of the first air outlet valve (13) and the second air outlet valve (14) are connected via a third connecting pipe (15); The third connecting pipe (15) leads to a fourth connecting pipe (16), the other end of the fourth connecting pipe (16) being connected in parallel to the inlet of the first air intake pipe (4) and the inlet of the second air intake pipe (5); a first angle seat valve (17) is provided on the fourth connecting pipe (16); A return pipe (18) is also led out from the middle of the output pipe (8), and the other end of the return pipe (18) is connected to the third connecting pipe (15); a backflush control valve (19) is provided on the return pipe (18); The first adsorption tower (2) and the second adsorption tower (3) alternately adsorb and desorb; When the first adsorption tower (2) is performing adsorption and the second adsorption tower (3) is performing desorption, if the oxygen concentration in the output pipe (8) is unqualified, the unqualified oxygen enters the second adsorption tower (3) through the reflux pipe (18). After the desorption of the second adsorption tower (3) is completed, the outlet of the first adsorption tower (2) is connected to the outlet of the second adsorption tower (3), and the outlet of the first adsorption tower (2) is connected to the inlet of the second adsorption tower (3).

2. A pressure swing adsorption air separation oxygen production system according to claim 1, characterized in that: The outlet of the air compressor (1) is connected to a cold dryer (20), an air buffer tank (21) and a main valve (22) in sequence through pipelines; the outlet of the main valve (22) is connected to the inlet of the first air intake pipe (4) and the inlet of the second air intake pipe (5) in parallel.

3. A pressure swing adsorption air separation oxygen production system according to claim 2, characterized in that: The outlet of the output pipe (8) is connected to an oxygen buffer tank (23); The outlet of the oxygen buffer tank (23) is connected in parallel to an oxygen collection pipe (24) and a reflux pipe (18); The oxygen collection pipe (24) is provided with an oxygen concentration detector (25) and a second angle seat valve (26).

4. A pressure swing adsorption air separation oxygen production system according to claim 3, characterized in that: The oxygen collecting pipe (24) is located between the outlet of the oxygen buffer tank (23) and the second angle seat valve (26) to lead out a pressure charging pipe (27). The other end of the pressure charging pipe (27) is connected to the return pipe (18), and the connection point is located at the outlet of the backwash control valve (19). A pressure charging control valve (28) is provided on the pressure charging pipe (27).

5. An operating method of a pressure swing adsorption air separation oxygen production system, characterized in that: The pressure swing adsorption air separation oxygen production system according to claim 4 comprises the following steps: Before the system starts working, all devices and valves are in a closed state; when starting working, the air compressor (1), the cold dryer (20) and the main valve (22) are first opened; S1, opening the first air inlet valve (9) to pressurize the first adsorption tower (2); when the pressure of the first adsorption tower (2) rises to a set pressure, opening the tail control valve (29) to allow the first adsorption tower (2) to inlet air for adsorption; Opening the backflush control valve (19), the second gas outlet valve (14) and the second desorption valve (12) allows the oxygen in the oxygen buffer tank (23) to enter the second adsorption tower (3) and exhaust the desorbed nitrogen; S2, the cavity between the oxygen-generating adsorbent and the outlet in the adsorption tower is set as an oxygen cavity, and the cavity between the oxygen-generating adsorbent and the inlet is set as an air cavity; The second desorption valve (12), the back-blowing control valve (19), the first air inlet valve (9) and the tail control valve (29) are closed, and the first air outlet valve (13) and the second air outlet valve (14) are opened, so that the outlets of the first adsorption tower (2) and the second adsorption tower (3) are connected, and the oxygen chamber of the first adsorption tower (2) is pressurized for the oxygen chamber of the second adsorption tower (3); S3, closing the second air outlet valve (14), opening the first angle seat valve (17) and the second air inlet valve (10), so that the outlet of the first adsorption tower (2) and the inlet of the second adsorption tower (3) are connected, and the oxygen chamber of the first adsorption tower (2) pressurizes the air chamber of the second adsorption tower (3); S4, closing the first angle seat valve (17) and the second air inlet valve (10), and opening the second air outlet valve (14) and the pressure control valve (28), so that the oxygen in the oxygen buffer tank (23) pressurizes the second adsorption tower (3); Closing the first gas outlet valve (13) and the first gas inlet valve (9), and opening the first desorption valve (11), so that the first adsorption tower (2) is depressurized for desorption; S5, closing the second air outlet valve (14) and the pressure control valve (28), and opening the second air inlet valve (10), so that the air pressurizes the second adsorption tower (3); S6, opening the backflush control valve (19) and the first air outlet valve (13), so that the oxygen in the oxygen buffer tank (23) enters the first adsorption tower (2), and the desorbed nitrogen is exhausted; Opening the second air intake valve (10) and the tail control valve (29) to allow the second adsorption tower (3) to intake air for adsorption; S7, closing the first desorption valve (11) and the back-blowing control valve (19), and opening the first gas outlet valve (13); Closing the second air inlet valve (10) and the tail control valve (29), and opening the second air outlet valve (14); The oxygen chamber of the second adsorption tower (3) pressurizes the oxygen chamber of the first adsorption tower (2); S8, closing the first air outlet valve (13), opening the first air inlet valve (9) and the first angle seat valve (17), so that the oxygen chamber of the second adsorption tower (3) pressurizes the air chamber of the first adsorption tower (2); S9, closing the first air inlet valve (9), the second air outlet valve (14) and the first angle seat valve (17); Opening the charging control valve (28), the first gas outlet valve (13) and the second desorption valve (12); The oxygen in the oxygen buffer tank (23) pressurizes the first adsorption tower (2), so that the second adsorption tower (3) depressurizes and desorbs; S10, closing the first gas outlet valve (13) and the charging control valve (28); S11, looping steps S1-S10 until the oxygen concentration detected by the oxygen concentration detector (25) meets the requirement, opening the second angle seat valve (26) to collect oxygen; assuming that the oxygen concentration generated during the air intake adsorption of the first adsorption tower (2) meets the requirement, at this time the second adsorption tower (3) is in a depressurized desorption state; S12, opening the backflush control valve (19), the second gas outlet valve (14) and the second desorption valve (12), so that the oxygen in the oxygen buffer tank (23) enters the second adsorption tower (3), and the desorbed nitrogen is exhausted; S13, closing the second desorption valve (12), the back-blowing control valve (19), the first air inlet valve (9) and the tail control valve (29), and opening the first air outlet valve (13) and the second air outlet valve (14), so that the outlets of the first adsorption tower (2) and the second adsorption tower (3) are connected, and the oxygen chamber of the first adsorption tower (2) is pressurized for the oxygen chamber of the second adsorption tower (3); S14, closing the second air outlet valve (14), opening the first angle seat valve (17) and the second air inlet valve (10), so that the outlet of the first adsorption tower (2) and the inlet of the second adsorption tower (3) are connected, and the oxygen chamber of the first adsorption tower (2) pressurizes the air chamber of the second adsorption tower (3); S15, closing the first air outlet valve (13) and the first angle seat valve (17); Opening the first desorption valve (11) and the second air intake valve (10); The first adsorption tower (2) is depressurized to desorb, and the second adsorption tower (3) is pressurized with compressed air; S16, opening the backflush control valve (19) and the first gas outlet valve (13), so that the oxygen in the oxygen buffer tank (23) enters the first adsorption tower (2), and the desorbed nitrogen is exhausted; At the same time, when the pressure in the second adsorption tower (3) reaches a set value, the tail control valve (29) is opened, and the second adsorption tower (3) is fed with air for adsorption; S17, closing the backflush control valve (19), the first desorption valve (11), the second air intake valve (10) and the tail control valve (29); Opening the first gas outlet valve (13) and the second gas outlet valve (14) so ​​that the oxygen chamber of the second adsorption tower (3) pressurizes the oxygen chamber of the first adsorption tower (2); S18, closing the first air outlet valve (13), opening the first air inlet valve (9) and the first angle seat valve (17), so that the oxygen chamber of the second adsorption tower (3) pressurizes the air chamber of the first adsorption tower (2); S19, opening the first air inlet valve (9) and the second desorption valve (12), and closing the first angle seat valve (17), so that the air pressurizes the first adsorption tower (2), and the second adsorption tower (3) depressurizes and desorbs; S20, looping steps S12-S19, continuously producing oxygen with a concentration that meets the requirements.

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