A kind of low temperature gas adsorption device and method of alternating regeneration

Abstract

The present invention discloses an alternately regenerated low-temperature gas adsorption device and method. When two adsorption units are switched, part of the low-temperature gas to be treated is introduced into the regeneration adsorption unit, and an adsorption treatment is performed once in the regeneration adsorption unit. Then, the part of the low-temperature gas to be treated is introduced into the working adsorption unit, and a secondary adsorption treatment is performed in the working adsorption unit. Through the above-mentioned optimized design, the regenerated adsorption unit is adsorbed once by part of the low-temperature gas, and this part of the gas is introduced into the working adsorption device for secondary adsorption. On the one hand, the adsorption unit to be switched is cooled down, and on the other hand, the adsorption effect of this part of the gas is guaranteed by two adsorptions, thereby ensuring the smooth switching of the working state and the regeneration state of the two adsorption units.

Description

Technical Field

[0001] The present invention relates to the technical field of gas purification, and in particular to an alternatingly regenerated low-temperature gas adsorption device and method. Background Art

[0002] The cryogenic gas adsorption device uses the principle of cryogenic adsorption and an adsorbent to remove gas impurities from the raw gas. At present, the more representative equipment at home and abroad include helium cryogenic purifiers, hydrogen cryogenic purifiers, etc. The helium cryogenic purifier is used to remove a small amount of nitrogen, oxygen, neon, etc. mixed in the helium, thereby providing high-purity or ultra-high-purity helium products, and has been widely used and proven to be effective. In the prior art, most cryogenic gas adsorption devices use liquid nitrogen to provide a low-temperature cold source, that is, the adsorber is immersed in a dewar injected with liquid nitrogen. When the adsorber is saturated with adsorption, the liquid nitrogen in the dewar needs to be extracted and the adsorber is heated to activate and regenerate the adsorbent inside it. The repeated injection and extraction process of liquid nitrogen has resulted in technical deficiencies such as complex equipment and large liquid nitrogen consumption.

[0003] In order to solve the problem of low-temperature gas adsorption, two adsorption units are usually set in parallel, and the adsorption effect is guaranteed by alternating adsorption and regeneration between the two. In the prior art, the adsorbent activation and regeneration process is generally carried out through steps such as purging nitrogen and vacuuming, so that the regenerated adsorption unit is at room temperature. However, when the two adsorption units are switched with each other, since the working adsorption unit is at a low temperature, and the activated and regenerated adsorption unit is at room temperature, the working temperature requirements are not met. If the raw gas is directly injected, the adsorption effect on the raw gas is poor, resulting in unqualified finished gas. In order to fully adsorb the raw gas during the switching stage between the two adsorption units, the adsorber that is about to be switched to work needs to be re-immersed in a dewar injected with liquid nitrogen for pre-cooling. The repeated injection and extraction process of liquid nitrogen has resulted in technical deficiencies such as complex equipment and large liquid nitrogen consumption. Summary of the invention

[0004] In order to solve the technical problems existing in the background technology, the present invention proposes an alternating regeneration low-temperature gas adsorption device and method.

[0005] The present invention also provides a low-temperature gas adsorption method with alternating regeneration, comprising the following steps:

[0006] When the two adsorption units are switched, at least part of the low-temperature gas to be treated is introduced into the regenerated adsorption unit, and an adsorption treatment is performed in the regenerated adsorption unit. Then, at least part of the low-temperature gas to be treated is introduced into the working adsorption unit, and a secondary adsorption treatment is performed in the working adsorption unit. When the regenerated adsorption unit reaches the preset working temperature, all the low-temperature gas to be treated is introduced into the regenerated adsorption unit for adsorption treatment, and the saturated working adsorption unit is regenerated.

[0007] Preferably, the step of introducing at least a portion of the low-temperature gas to be treated into the regenerated adsorption unit specifically includes connecting the adsorption inlets of the two adsorption units to the raw gas input end, and connecting the adsorption outlets of the two adsorption units to the product gas output end, and the two adsorption units are connected via a connecting pipeline; and the temperature rise of the working adsorption unit is controlled by gradually increasing the flow rate of the low-temperature gas introduced into the regenerated adsorption unit.

[0008] The present invention also proposes an alternatingly regenerated low-temperature gas adsorption device, comprising: two adsorption units, a raw gas input end and a product gas output end, the adsorption inlets of the two adsorption units are connected to the raw gas input end, and the adsorption outlets of the two adsorption units are connected to the product gas output end; a connecting pipeline is provided between the two adsorption units.

[0009] Preferably, the adsorption inlet and the adsorption outlet are respectively located at two ends of the adsorption unit, a circulating gas port is provided in the middle of the adsorption unit, and the circulating gas ports of the two adsorption units are connected through the connecting pipeline.

[0010] Preferably, an inlet valve is provided at the adsorption inlet, an outlet valve is provided at the adsorption outlet, and a switching valve is provided on the communication pipeline;

[0011] The two adsorption units are switched by opening the inlet valve and the switching valve of the regenerated adsorption unit, introducing part of the low-temperature gas to be treated into the regenerated adsorption unit for primary adsorption, and then entering the working adsorption unit through the connecting pipeline for secondary adsorption.

[0012] Preferably, the adsorption unit includes an adsorption cylinder and a gas separation membrane, the gas separation membrane is located in the adsorption cylinder and divides the adsorption cylinder into an adsorption area and a transition area, the adsorption area and the transition area are both filled with adsorption fillers, the filler density in the adsorption area is greater than the filler density in the transition area, a circulation inlet is provided on the transition area, and the adsorption inlet is located on the adsorption area.

[0013] Preferably, the adsorption outlet is located on the transition area.

[0014] Preferably, support covers are provided on both sides of the gas separation membrane, and gas holes are provided on the support covers.

[0015] Preferably, the gas separation membrane has a cover structure extending from the top to the middle of the adsorption cylinder, the adsorption area is located inside the gas separation membrane and the transition area surrounds the periphery of the adsorption area.

[0016] Preferably, the adsorption outlet is located at the bottom of the transition area, a circulation outlet is provided at the bottom of the transition area, and the adsorption inlet is located at the top of the adsorption area.

[0017] In the present invention, the proposed alternating regeneration low-temperature gas adsorption device and method, when the two adsorption units are switched, part of the low-temperature gas to be treated is introduced into the regeneration adsorption unit, and a first adsorption treatment is performed in the regeneration adsorption unit, and then the part of the low-temperature gas to be treated is introduced into the working adsorption unit, and a second adsorption treatment is performed in the working adsorption unit. Through the above-mentioned optimized design, the regenerated adsorption unit is adsorbed once by part of the low-temperature gas, and this part of the gas is introduced into the working adsorption device for secondary adsorption. On the one hand, the adsorption unit to be switched is cooled, and on the other hand, the adsorption effect of this part of the gas is guaranteed by two adsorptions, thereby ensuring the smooth switching of the working state and the regeneration state of the two adsorption units. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the pipeline of an embodiment of an alternatingly regenerated low-temperature gas adsorption device proposed by the present invention.

[0019] Figure 2 A schematic diagram of the pipeline of another embodiment of an alternatingly regenerated low-temperature gas adsorption device proposed by the present invention.

[0020] Figure 3 This is a schematic diagram of the piping of an adsorption unit in another embodiment of an alternatingly regenerated low-temperature gas adsorption device proposed by the present invention.

[0021] Figure 4 This is a schematic diagram of the internal structure of an adsorption tube in one embodiment of an alternating regeneration low-temperature gas adsorption device proposed by the present invention.

[0022] Figure 5 for Figure 4 Schematic diagram of the enlarged structure of area A in the middle.

[0023] Figure 6 This is a schematic diagram of the exterior of an adsorption cylinder in one embodiment of an alternatingly regenerated low-temperature gas adsorption device proposed by the present invention. DETAILED DESCRIPTION

[0024] like Figures 1 to 6 As shown, Figure 1 This is a schematic diagram of a pipeline of an embodiment of an alternately regenerated low-temperature gas adsorption device proposed by the present invention. Figure 2 This is a schematic diagram of a pipeline of another embodiment of an alternately regenerated low-temperature gas adsorption device proposed by the present invention. Figure 3 This is a schematic diagram of the pipeline of the adsorption unit in another embodiment of the alternating regeneration low-temperature gas adsorption device proposed by the present invention. Figure 4This is a schematic diagram of the internal structure of an adsorption tube in one embodiment of an alternately regenerated low-temperature gas adsorption device proposed by the present invention. Figure 5 for Figure 4 Schematic diagram of the enlarged structure of area A in the middle. Figure 6 This is a schematic diagram of the exterior of an adsorption cylinder in one embodiment of an alternatingly regenerated low-temperature gas adsorption device proposed by the present invention.

[0025] Reference Figure 1 The present invention proposes an alternatingly regenerated low-temperature gas adsorption device, comprising: two adsorption units 10, a raw gas input end and a product gas output end, the raw gas input end inputs the raw gas pre-cooled by low temperature, the adsorption inlets of the two adsorption units 10 are connected with the raw gas input end, and the adsorption outlets of the two adsorption units 10 are connected with the product gas output end; a connecting pipeline is provided between the two adsorption units 10.

[0026] When the two adsorption units 10 are switched, part of the low-temperature gas to be treated is introduced into the regenerated adsorption unit 10 for primary adsorption, and then enters the working adsorption unit 10 through the connecting pipeline for secondary adsorption. When the regenerated adsorption unit 10 reaches the preset working temperature, all the low-temperature gas to be treated is introduced into the regenerated adsorption unit 10 for adsorption treatment, and the saturated working adsorption unit 10 is regenerated.

[0027] In this embodiment, the proposed alternating regeneration low-temperature gas adsorption device and method, when the two adsorption units are switched, part of the low-temperature gas to be treated is introduced into the regeneration adsorption unit, and a first adsorption treatment is performed in the regeneration adsorption unit, and then the part of the low-temperature gas to be treated is introduced into the working adsorption unit, and a second adsorption treatment is performed in the working adsorption unit. Through the above-mentioned optimized design, the regenerated adsorption unit is adsorbed once by part of the low-temperature gas, and this part of the gas is introduced into the working adsorption device for secondary adsorption. On the one hand, the adsorption unit to be switched is cooled, and on the other hand, the adsorption effect of this part of the gas is guaranteed by two adsorptions, thereby ensuring the smooth switching of the working state and the regeneration state of the two adsorption units.

[0028] In a specific implementation of the device of this embodiment, an inlet valve 1 is provided at the adsorption inlet, an outlet valve 3 is provided at the adsorption outlet, and a switching valve 2 is provided on the connecting pipeline;

[0029] When the two adsorption units 10 are switched, part of the low-temperature gas to be treated is introduced into the regenerated adsorption unit 10 for primary adsorption by opening the inlet valve 1 and the switching valve 2 of the regenerated adsorption unit 10, and then enters the working adsorption unit 10 through the connecting pipeline for secondary adsorption. In the process of introducing part of the low-temperature gas to be treated into the regenerated adsorption unit 10, the temperature impact on the working adsorption unit 10 is controlled by gradually increasing the flow rate of the low-temperature gas introduced into the regenerated adsorption unit 10, so as to ensure that the temperature rise of the gas flowing out of the regenerated adsorption unit on the working adsorption device is kept in a relatively low range, generally controlled within 3K.

[0030] In the specific working process, keep the inlet valve and outlet valve of the working adsorption unit open, gradually open the switching valve, keep the outlet valve of the regeneration adsorption unit closed, and open the switching valve between the regeneration adsorption unit and the working adsorption unit. At this time, the low-temperature gas is divided into two streams, one directly enters the inlet of the working adsorption unit, and the other enters the regeneration adsorption unit. After one adsorption in the regeneration adsorption unit, it flows into the inlet of the working adsorption unit through the connecting pipeline, and the working adsorption unit performs secondary adsorption. With the long-term cooling of the low-temperature gas flowing into the regeneration adsorption unit, the temperature in the regeneration adsorption unit gradually decreases until it reaches the set adsorption temperature. At this time, the inlet valve of the working adsorption unit is completely closed, and the inlet valve of the regeneration adsorption unit is opened. The second adsorption device is used for adsorption, and the first adsorption device immediately starts activation and regeneration. Until the activation and regeneration of the first adsorption device is completed and the adsorption of the second adsorption device is close to saturation, switch again according to the above process.

[0031] In a specific embodiment, in order to ensure smooth gas flow between the two adsorption units, a circulation outlet is provided at the bottom of the adsorption unit 10 and a circulation inlet 103 is provided at the top, and a connecting pipe is provided between the circulation outlet of one adsorption unit 10 and the circulation inlet 103 of another adsorption unit 10 to connect the two.

[0032] Since the gas will be blocked by the adsorbent when passing through the adsorption unit, there will be a pressure drop. Therefore, in the above control process, when the gas flowing out of the regeneration adsorption unit flows into the working adsorption unit through the connecting pipeline, there is a certain pressure difference with the gas directly flowing into the working adsorption unit. The two gases are directly merged, which will affect the flow rate of the gas through the connecting pipeline.

[0033] Reference Figure 2 and 3In one embodiment of the adsorption unit, the adsorption inlet and the adsorption outlet are respectively located at both ends of the adsorption unit 10, and a circulating gas port is provided in the middle of the adsorption unit 10, and the circulating gas ports of the two adsorption units 10 are connected through the connecting pipeline. By arranging the circulating gas port in the middle of the two adsorption units, when the gas flowing out from the middle of the regenerated adsorption unit enters the middle of the working adsorption unit, its pressure is consistent with that of the middle of the working adsorption unit, thereby eliminating the problem of pressure difference caused by air intake from the head and tail ends.

[0034] In one specific design, when the adsorption unit 10 includes a single adsorption cylinder, the circulating gas port can be set in the middle of the adsorption cylinder. In another specific design, when the adsorption unit 10 includes at least two adsorption cylinders connected in series, the circulating gas port can be set in the series pipeline between two adjacent adsorption cylinders.

[0035] In order to solve the problem that there is a certain pressure difference between the two gases in the working adsorption unit during the switching process of the two adsorption units 10, the interior of the adsorption cylinder can also be improved. Figure 4 In the specific design of the adsorption unit, the adsorption unit 10 includes an adsorption cylinder 11 and a gas separation membrane 12. The gas separation membrane 12 is located in the adsorption cylinder 11 and divides the adsorption cylinder 11 into an adsorption area 101 and a transition area 102. The adsorption area 101 and the transition area 102 are both filled with adsorption fillers. The filler density in the adsorption area 101 is greater than the filler density in the transition area 102. A circulation inlet 103 is provided on the transition area 102, and the adsorption inlet 104 is located on the adsorption area 101. By adjusting the filler density, the gas resistance directly entering the adsorption area is greater than the gas resistance entering the transition area, so as to avoid the high-pressure gas directly entering the working adsorption unit from affecting the low-pressure gas from the regeneration adsorption unit.

[0036] In a further specific design, the adsorption outlet is located on the transition region 102, so that the higher pressure gas is depressurized in the adsorption region, merges with the lower pressure gas in the transition region, and is finally discharged from the adsorption outlet.

[0037] In addition, in order to avoid stress concentration when the gas passes through and damage to the gas separation membrane, refer to Figure 5 A support cover 13 is provided on both sides of the gas separation membrane 12, and a gas hole is provided on the support cover 13. The support cover protects the separation membrane from both sides of the gas separation membrane, and forms a gas channel between the gas holes on the inner and outer support covers.

[0038] In the specific design of the interior of the adsorption cylinder, the gas separation membrane 12 has a cover structure extending from the top to the middle of the adsorption cylinder 11, the adsorption area 101 is located inside the gas separation membrane 12 and the transition area 102 is surrounded by the periphery of the adsorption area 101. Further, the adsorption outlet 105 is located at the bottom of the transition area 102, the circulation inlet 103 is located at the top of the transition area 102, and the adsorption inlet 104 is located at the top of the adsorption area 101.

[0039] In actual design, a purge gas inlet is also provided at the bottom of the adsorption tube. During the activation and regeneration stage, an external purge gas can be used to purge the adsorbent in the adsorption tube from the bottom and blown out from the top. Unlike the small pressure difference between the upstream and downstream inlet and outlet during the adsorption stage, the pressure difference before and after the liquid nitrogen purge outlet during the purge stage is large. The gas purged from the outer transition area can also flow into the inner adsorption area through the gas separation membrane and finally be discharged through the top outlet, ensuring that both the inner and outer adsorbent areas are effectively purged and activated and regenerated.

[0040] As a preference, in order to switch between the two adsorption cylinders, the regenerated adsorption cylinder needs to be cooled down at a relatively fast speed so that it reaches the designed adsorption temperature before the working adsorption unit is saturated with adsorption. Figure 6 , a refrigeration coil 106 can be set on the adsorption cylinder. When the adsorption unit is activated and regenerated, its temperature is room temperature or higher than room temperature. At this time, the liquid nitrogen channel is opened to achieve rapid cooling of the adsorption cylinder, and further cool the adsorption cylinder and its internal adsorbent to the liquid nitrogen temperature zone. In the specific design, the refrigeration coil 106 can be set inside the adsorption cylinder or outside the adsorption cylinder to increase the refrigeration effect.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A low-temperature gas adsorption method with alternating regeneration, characterized in that: The following steps are involved: When the two adsorption units are switched, at least part of the low-temperature gas to be treated is introduced into the regenerated adsorption unit (10), and a primary adsorption treatment is performed in the regenerated adsorption unit (10). Then, at least part of the low-temperature gas to be treated is introduced into the working adsorption unit (10), and a secondary adsorption treatment is performed in the working adsorption unit (10). When the regenerated adsorption unit (10) reaches a preset working temperature, all of the low-temperature gas to be treated is introduced into the regenerated adsorption unit (10) for adsorption treatment, and the saturated working adsorption unit (10) is regenerated.

2. The alternating regeneration low-temperature gas adsorption method according to claim 1, characterized in that: The step of introducing at least a portion of the low-temperature gas to be treated into the regenerated adsorption unit (10) specifically comprises connecting the adsorption inlets (104) of the two adsorption units (10) to the raw gas input end, and connecting the adsorption outlets of the two adsorption units (10) to the product gas output end, and connecting the two adsorption units (10) via a connecting pipeline; and controlling the temperature rise of the working adsorption unit (10) by gradually increasing the flow rate of the low-temperature gas introduced into the regenerated adsorption unit (10).

3. An adsorption device for realizing the low-temperature gas adsorption method of alternating regeneration according to claim 2, characterized in that: include: Two adsorption units (10), a raw gas input end and a product gas output end, the adsorption inlets (104) of the two adsorption units (10) are connected to the raw gas input end, and the adsorption outlets of the two adsorption units (10) are connected to the product gas output end; and a connecting pipeline is provided between the two adsorption units (10).

4. The adsorption device according to claim 3, characterized in that: The adsorption inlet (104) and the adsorption outlet are respectively located at two ends of the adsorption unit (10); a circulating gas port is provided in the middle of the adsorption unit (10); and the circulating gas ports of the two adsorption units (10) are connected via the connecting pipeline.

5. The adsorption device according to claim 3, characterized in that: An inlet valve (1) is provided at the adsorption inlet (104), an outlet valve (3) is provided at the adsorption outlet, and a switching valve (2) is provided on the connecting pipeline; The two adsorption units (10) are switched, specifically by opening the inlet valve (1) and the switching valve (2) of the regenerated adsorption unit (10), introducing part of the low-temperature gas to be treated into the regenerated adsorption unit (10) for primary adsorption, and then entering the working adsorption unit (10) through the connecting pipeline for secondary adsorption.

6. The adsorption device according to claim 3, characterized in that: The adsorption unit (10) comprises an adsorption cylinder (11) and a gas separation membrane (12); the gas separation membrane (12) is located in the adsorption cylinder (11) and divides the adsorption cylinder (11) into an adsorption region (101) and a transition region (102); the adsorption region (101) and the transition region (102) are both filled with adsorption fillers; the filler density in the adsorption region (101) is greater than the filler density in the transition region (102); a circulation inlet (103) is provided on the transition region (102), and the adsorption inlet (104) is located on the adsorption region (101).

7. The adsorption device according to claim 6, characterized in that: The adsorption outlet is located on the transition area (102).

8. The adsorption device according to claim 6, characterized in that: Support covers (13) are provided on both sides of the gas separation membrane (12), and gas holes are provided on the support covers (13).

9. The adsorption device according to claim 7 or 8, characterized in that: The gas separation membrane (12) has a cover structure extending from the top to the middle of the adsorption cylinder (11), the adsorption area (101) is located inside the gas separation membrane (12) and the transition area (102) surrounds the periphery of the adsorption area (101).

10. The adsorption device according to claim 9, characterized in that: The adsorption outlet is located at the bottom of the transition area (102), a circulation outlet is provided at the bottom of the transition area (102), and the adsorption inlet (104) is located at the top of the adsorption area (101).

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