Carbon molecular sieve oxygen generating device

Abstract

The utility model discloses a carbon molecular sieve oxygen preparation device, including fore adsorption tower and post adsorption tower, is equipped with first import (100) and first export (101) on fore adsorption tower, is equipped with first pressure valve (102) at first export (101), is equipped with first filling layer (103) in fore adsorption tower, is equipped with second import (104) and second export (105) on post adsorption tower, is equipped with second pressure valve (122) at second export (105), is equipped with the second filling layer (106) between second import (104) and second export (105) in post adsorption tower, second import (104) connects first pressure valve (102), is equipped with first check valve (107) between second import (104) and first pressure valve (102). The utility model has the advantages of being capable of preparing high-purity oxygen and low oxygen production cost.

Description

Technical Field

[0001] This utility model belongs to the field of oxygen generation devices, and particularly relates to a carbon molecular sieve oxygen generation device. Background Technology

[0002] Currently, there are two main oxygen production processes. The first is cryogenic separation, which utilizes the difference in boiling points of different gases to cool and liquefy a mixed gas under high pressure, thereby achieving the purpose of separating the mixed gases. Cryogenic separation can obtain high-purity oxygen with a purity of over 99%, but the equipment cost and energy consumption cost are high, resulting in a high production cost. The second is pressure swing adsorption, which utilizes the characteristic that oxygen diffuses faster than nitrogen in the air under high pressure. Oxygen enters a carbon molecular sieve while nitrogen is discharged. The discharged nitrogen has a purity of over 99%. Then, a vacuum is drawn to desorb the oxygen from the carbon molecular sieve, but only oxygen with a purity of 93-95% can be obtained. The purity is low, and it is impossible to obtain high-purity oxygen with a purity of over 99%. The second method is generally used to obtain high-purity nitrogen for the carbon molecular sieve used in nitrogen production, and on the side, it produces oxygen with a lower purity. The oxygen production cost is lower, but the low purity of the oxygen limits its application range, and the selling price is also relatively low.

[0003] Existing oxygen generation devices using pressure swing adsorption (PSA) include an adsorption tower with a packed layer of carbon molecular sieves. The tower has an inlet and an outlet. Compressed air enters the tower through the inlet and passes through the packed layer. Oxygen is adsorbed by the carbon molecular sieves, while nitrogen is discharged from the outlet, resulting in separated high-purity nitrogen with a purity exceeding 99.99%. However, once the adsorbed oxygen in the packed layer reaches a certain level, the adsorption tower depressurizes, desorbing the oxygen from the carbon molecular sieves and discharging oxygen at the outlet. Because some nitrogen remains in the gaps between the carbon molecular sieves, this nitrogen mixes with the desorbed oxygen, resulting in a low concentration of oxygen at the outlet, with a purity of only about 93-95%, making it impossible to obtain truly high-purity oxygen. In existing oxygen generation devices, the adsorption and desorption of oxygen on the carbon molecular sieves occur alternately, with the outlet alternately outputting nitrogen and oxygen. Utility Model Content

[0004] The purpose of this invention is to provide a carbon molecular sieve oxygen generator. This invention has the advantages of producing high-purity oxygen at a low cost.

[0005] The technical solution of this utility model is as follows: A carbon molecular sieve oxygen generation device includes a pre-adsorption tower and a post-adsorption tower. The pre-adsorption tower is provided with a first inlet and a first outlet, and a first pressure valve is provided at the first outlet. A first packing layer is provided inside the pre-adsorption tower between the first inlet and the first outlet. The post-adsorption tower is provided with a second inlet and a second outlet, and a second pressure valve is provided at the second outlet. A second packing layer is provided inside the post-adsorption tower between the second inlet and the second outlet. The second inlet is connected to the first pressure valve, and a first check valve is provided between the second inlet and the first pressure valve.

[0006] In the aforementioned carbon molecular sieve oxygen generator, the first inlet is located at the bottom of the pre-adsorption tower, the first outlet is located at the top of the pre-adsorption tower, the second inlet is located at the bottom of the post-adsorption tower, and the second outlet is located at the top of the post-adsorption tower.

[0007] In the aforementioned carbon molecular sieve oxygen generator, the first filling layer includes a first lower partition plate near the first inlet and a first upper partition plate near the first outlet. A first lower buffer cavity is formed between the first lower partition plate and the first inlet, and a first upper buffer cavity is formed between the first outlet and the first upper partition plate. The materials of the first lower partition plate and the first upper partition plate are both perforated plates, and carbon molecular sieves are filled between the first lower partition plate and the first upper partition plate.

[0008] In the aforementioned carbon molecular sieve oxygen generator, the second filling layer includes a second lower partition plate near the second inlet and a second upper partition plate near the second outlet. A second lower buffer cavity is formed between the second lower partition plate and the second inlet, and a second upper buffer cavity is formed between the second outlet and the second upper partition plate. The material of the second lower partition plate and the material of the second upper partition plate are both perforated plates, and carbon molecular sieves are filled between the second lower partition plate and the second upper partition plate.

[0009] In the aforementioned carbon molecular sieve oxygen generator, a four-way valve is provided on the rear side of the second pressure valve. The inlet of the four-way valve is connected to the second pressure valve, one of the outlets of the four-way valve is connected to a nitrogen storage tank through a first pressurizing device, the other outlet of the four-way valve is connected to an oxygen storage tank through a second pressurizing device, and the remaining outlet of the four-way valve is connected to the atmosphere.

[0010] In the aforementioned carbon molecular sieve oxygen generator, each of the three outlets of the four-way valve is equipped with a second one-way valve.

[0011] In the aforementioned carbon molecular sieve oxygen generation device, the volume of the post-adsorption tower is 30-50 times that of the pre-adsorption tower.

[0012] In the aforementioned carbon molecular sieve oxygen generator, a third one-way valve is provided on the front side of the first inlet.

[0013] Compared with existing technologies, this invention includes two adsorption towers connected in series. Each adsorption tower has a pressure control valve at its outlet to control the gas pressure. During the high-pressure oxygen adsorption stage, the oxygen generator outputs high-purity nitrogen, maintaining a higher pressure in the pre-adsorption tower than in the post-adsorption tower. After stopping the output of high-purity nitrogen, the pressure in the pre-adsorption tower is reduced, causing some of the oxygen in the pre-adsorption tower to desorb first, carrying away the residual nitrogen in both adsorption towers before entering the oxygen storage tank to obtain high-purity oxygen with a purity exceeding 99.5%. Since the high-purity oxygen is produced using pressure swing adsorption, the oxygen production cost is relatively low. Therefore, this invention has the advantages of producing high-purity oxygen at a low cost.

[0014] Furthermore, by setting multiple one-way valves to prevent gas backflow, and by setting two buffer chambers inside the adsorption tower, the gas can pass through the packing layer more evenly in the horizontal cross section, thereby improving the oxygen adsorption efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] The labels in the attached diagram are as follows: 100-First inlet, 101-First outlet, 102-First pressure valve, 103-First filling layer, 104-Second inlet, 105-Second outlet, 106-Second filling layer, 107-First check valve, 108-First lower baffle, 109-First upper baffle, 110-First lower buffer chamber, 111-First upper buffer chamber, 112-Second lower baffle, 113-Second upper baffle, 114-Second lower buffer chamber, 115-Second upper buffer chamber, 116-Four-way valve, 117-First pressurizing device, 118-Nitrogen storage tank, 119-Second pressurizing device, 120-Oxygen storage tank, 121-Second check valve, 122-Second pressure valve, 123-Third check valve. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0018] Example: A carbon molecular sieve oxygen generator, such as Figure 1 As shown, it includes a pre-adsorption tower and a post-adsorption tower, both of which are pressure vessels. The volume of the post-adsorption tower is 40 times that of the pre-adsorption tower.

[0019] The pre-adsorption tower has a first inlet 100 at the bottom, a third one-way valve 123 at the front of the first inlet 100, a first outlet 101 at the top, a first pressure valve 102 at the first outlet 101, and a first packing layer 103 located between the first inlet 100 and the first outlet 101 inside the pre-adsorption tower. The first packing layer 103 includes a first lower baffle 108 near the first inlet 100 and a first upper baffle 109 near the first outlet 101. A first lower buffer chamber 110 is formed between the first lower baffle 108 and the first inlet 100, and a first upper buffer chamber 111 is formed between the first outlet 101 and the first upper baffle 109. The material of the first lower baffle 108 and the first upper baffle 109 is a perforated plate. Carbon molecular sieves of specification CMS-360 are filled between the first lower baffle 108 and the first upper baffle 109.

[0020] The post-adsorption tower has a second inlet 104 at the bottom and a second outlet 105 at the top. A second pressure valve 122 is located at the second outlet 105. A second packing layer 106 is located inside the post-adsorption tower between the second inlet 104 and the second outlet 105. The second inlet 104 is connected to a first pressure valve 102, and a first check valve 107 is located between the second inlet 104 and the first pressure valve 102. The second packing layer 106 includes a second lower baffle 112 near the second inlet 104 and a second upper baffle 113 near the second outlet 105. A second lower buffer chamber 114 is formed between the second lower baffle 112 and the second inlet 104, and a second upper buffer chamber 115 is formed between the second outlet 105 and the second upper baffle 113. The material of the second lower baffle 112 and the second upper baffle 113 is a perforated plate. Carbon molecular sieves of specification CMS-360 are filled between the second lower baffle 112 and the second upper baffle 113.

[0021] A four-way valve 116 is provided on the rear side of the second pressure valve 122. Each of the three outlets of the four-way valve 116 is equipped with a second one-way valve 121. The inlet of the four-way valve 116 is connected to the second pressure valve 122. One outlet of the four-way valve 116 is connected to a nitrogen storage tank 118 via a first pressurizing device 117. Another outlet of the four-way valve 116 is connected to an oxygen storage tank 120 via a second pressurizing device 119. The remaining outlet of the four-way valve 116 is connected to the atmosphere. Both the first pressurizing device 117 and the second pressurizing device 119 are air compressors.

[0022] Each of the aforementioned buffer cavities should have a relatively small volume while ensuring sufficient radial diffusion of the gas.

[0023] Preferably, both the first pressure valve 102 and the second pressure valve 122 are 700BP back pressure valves. The characteristic is that when the inlet pressure reaches the set pressure, the valve opens, so that the inlet pressure is kept at a constant set pressure and is not affected by the outlet pressure.

[0024] Instructions for use: Follow these steps in sequence.

[0025] 1) Set the opening pressure of the first pressure valve 102 to 1.5MPa and the opening pressure of the second pressure valve 122 to 0.85MPa, and connect the second pressure valve 122 to the atmosphere through the four-way valve 116.

[0026] 2) Adsorption Stage: Compressed air, after being degreased, dehydrated, and dust-free, enters the pre-adsorption tower through the third one-way valve 123 and the first inlet 100. Passing through the first packed layer 103, some oxygen is adsorbed there. The remaining gas sequentially enters the post-adsorption tower through the first outlet 101, the first pressure valve 102, the first one-way valve 107, and the second inlet 104. Oxygen in the remaining gas is adsorbed in the second packed layer 106. Nitrogen is discharged to the atmosphere through the second outlet 105, the second pressure valve 122, and the four-way valve 116. Because residual air remains in the second upper buffer chamber 115 and subsequent pipelines when the equipment is first started, the discharged nitrogen is impure and needs to be discharged to the atmosphere first. After the residual air is discharged, high-purity nitrogen enters the nitrogen storage tank 118 through the four-way valve 116, the corresponding second one-way valve 121, and the first pressurization device 117, where high-purity nitrogen is collected.

[0027] 3) Based on the total amount of carbon molecular sieves filled in the two towers, it can be determined how much compressed air needs to be input before the carbon molecular sieves reach their oxygen adsorption limit. Based on common knowledge in the field, it can be calculated that before the carbon molecular sieves reach their oxygen adsorption limit, the input of compressed air should be stopped, and the second pressure valve 122 should be connected to the atmosphere through the four-way valve 116.

[0028] 4) Stage of cleaning residual nitrogen in the tower: Reduce the opening pressure of the first pressure valve 102 to 0.9MPa, the gas pressure inside the pre-adsorption tower decreases, some oxygen in the first packing layer 103 is desorbed, and carries the nitrogen remaining in the pre-adsorption tower into the post-adsorption tower. The gas pressure inside the post-adsorption tower increases, the second pressure valve 122 opens, and oxygen carrying nitrogen is discharged to the atmosphere.

[0029] 5) The opening pressures of the first pressure valve 102 and the second pressure valve 122 are gradually reduced and eventually adjusted to the normally open state. The gas pressure inside the two towers gradually decreases, oxygen desorbs, and is discharged from the second pressure valve 122. After purging the residual air in the subsequent pipeline of the second pressure valve 122, the four-way valve 116 is quickly switched, and the oxygen enters the oxygen storage tank 120 through the second pressurization device 119, collecting high-purity oxygen. After multiple batches of sampling inspection, the purity of the high-purity oxygen is distributed between 99.58% and 99.74%, with the remaining impurities mainly being argon.

[0030] The above steps 1) to 5) constitute one cycle, and are performed sequentially to alternately obtain high-purity oxygen and high-purity nitrogen.

[0031] In this invention, the volume of the pre-adsorption tower is much smaller than that of the post-adsorption tower, primarily to provide oxygen to the post-adsorption tower to flush out residual nitrogen. Simultaneously, even after oil and dust removal, compressed air still carries a small amount of oil molecules and dust, which can poison the carbon molecular sieve. The pre-adsorption tower intercepts these oil molecules and dust, ensuring that carbon molecular sieve poisoning only occurs within the pre-adsorption tower. Once the carbon molecular sieve is poisoned, only the carbon molecular sieve in the pre-adsorption tower needs to be replaced, resulting in less replacement and lower operating costs.

[0032] With further optimization, a corresponding control system can be installed to automate the above steps, saving manpower costs.

[0033] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

Claims

1. A carbon molecular sieve oxygen generator, characterized in that: The system includes a pre-adsorption tower and a post-adsorption tower. The pre-adsorption tower is provided with a first inlet (100) and a first outlet (101). A first pressure valve (102) is provided at the first outlet (101). A first packing layer (103) is provided inside the pre-adsorption tower between the first inlet (100) and the first outlet (101). The post-adsorption tower is provided with a second inlet (104) and a second outlet (105). A second pressure valve (122) is provided at the second outlet (105). A second packing layer (106) is provided inside the post-adsorption tower between the second inlet (104) and the second outlet (105). The second inlet (104) is connected to the first pressure valve (102). A first check valve (107) is provided between the second inlet (104) and the first pressure valve (102).

2. The carbon molecular sieve oxygen generator according to claim 1, characterized in that: The first inlet (100) is located at the bottom of the pre-adsorption tower, the first outlet (101) is located at the top of the pre-adsorption tower, the second inlet (104) is located at the bottom of the post-adsorption tower, and the second outlet (105) is located at the top of the post-adsorption tower.

3. The carbon molecular sieve oxygen generator according to claim 2, characterized in that: The first filling layer (103) includes a first lower partition (108) near the first inlet (100) and a first upper partition (109) near the first outlet (101). A first lower buffer cavity (110) is formed between the first lower partition (108) and the first inlet (100), and a first upper buffer cavity (111) is formed between the first outlet (101) and the first upper partition (109). Both the first lower partition (108) and the first upper partition (109) are perforated plates, and carbon molecular sieves are filled between the first lower partition (108) and the first upper partition (109).

4. The carbon molecular sieve oxygen generator according to claim 3, characterized in that: The second filling layer (106) includes a second lower partition (112) near the second inlet (104) and a second upper partition (113) near the second outlet (105). A second lower buffer cavity (114) is formed between the second lower partition (112) and the second inlet (104), and a second upper buffer cavity (115) is formed between the second outlet (105) and the second upper partition (113). Both the second lower partition (112) and the second upper partition (113) are perforated plates, and carbon molecular sieves are filled between the second lower partition (112) and the second upper partition (113).

5. The carbon molecular sieve oxygen generator according to claim 1, characterized in that: A four-way valve (116) is provided on the rear side of the second pressure valve (122). The inlet of the four-way valve (116) is connected to the second pressure valve (122). One of the outlets of the four-way valve (116) is connected to the nitrogen storage tank (118) through the first pressurizing device (117). The other outlet of the four-way valve (116) is connected to the oxygen storage tank (120) through the second pressurizing device (119). The remaining outlet of the four-way valve (116) is connected to the atmosphere.

6. The carbon molecular sieve oxygen generator according to claim 5, characterized in that: The four-way valve (116) is equipped with a second check valve (121) on each of its three outlets.

7. The carbon molecular sieve oxygen generator according to claim 1, characterized in that: The volume of the post-adsorption tower is 30-50 times that of the pre-adsorption tower.

8. The carbon molecular sieve oxygen generator according to claim 1, characterized in that: A third check valve (123) is provided on the front side of the first inlet (100).

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