An adsorption tower for a pressure swing adsorption nitrogen generation system and a pressure swing adsorption nitrogen generation system

Abstract

The utility model discloses a kind of adsorption tower and pressure swing adsorption nitrogen generation system for pressure swing adsorption nitrogen generation system, the adsorption tower includes tower body, multistage flow guide mechanism and molecular sieve filler layer being set in tower body, multistage flow guide mechanism includes one-stage flow guide, the second flow uniformity board being arranged in the top of one-stage flow guide, the buffer layer being located in the top of second flow uniformity board, one-stage flow guide is conical plate structure with tip end towards air inlet, a plurality of first through holes are set in one-stage flow guide, second flow uniformity board is covered in the top of one-stage flow guide, a plurality of second through holes are set in second flow uniformity board, tertiary buffer layer is composed of inert filler being laid on second flow uniformity board, the particle size of inert filler is greater than the filler particle size of molecular sieve filler layer. The utility model passes through multistage flow guide and converts disordered air into uniform plug flow, significantly improves molecular sieve utilization, reduces compressed air consumption, and then significantly improves the overall energy-saving effect of pressure swing adsorption nitrogen generation system.

Description

Technical Field

[0001] This utility model relates to the field of nitrogen generation equipment technology, specifically to an adsorption tower and a pressure swing adsorption nitrogen generation system. Background Technology

[0002] Pressure Swing Adsorption (PSA) nitrogen generation systems are the preferred nitrogen production method for small and medium-sized nitrogen users, holding an important position in the industrial gas supply field. They are commonly used in industries requiring stable nitrogen production, such as chemical, electronics, food, and pharmaceutical industries. The working principle of a PSA nitrogen generation system is based on the difference in adsorption capacity of carbon molecular sieves for nitrogen and oxygen, achieving oxygen-nitrogen separation and producing nitrogen. Existing PSA nitrogen generation systems typically include an air compressor, a refrigerated dryer, an air buffer tank, an adsorption tower, a nitrogen buffer tank, and a control system. Among these, the adsorption tower is the core separation unit of the PSA nitrogen generation system, and its performance directly determines the nitrogen production efficiency, purity, and operational stability of the entire system.

[0003] Currently, traditional PSA nitrogen generation systems mostly use "simple cavity structures" for their adsorption towers. These towers are simply filled with molecular sieves as the adsorption medium, without any auxiliary structures for airflow guidance or molecular sieve fixation. Compressed air enters the cavity directly from the tower inlet and diffuses naturally before contacting the molecular sieve bed. This design has the following disadvantages: 1. Low adsorption efficiency and poor utilization of molecular sieve: Insufficient contact between compressed air and molecular sieve, excessive adsorption in some areas and insufficient adsorption in others, resulting in low nitrogen output per unit volume of molecular sieve. 2. Molecular sieves are prone to pulverization and have a short lifespan: Molecular sieves are prone to particle wear and breakage during operation, requiring frequent replacement (molecular sieves are expensive), which not only increases the cost of consumables, but also causes production interruptions due to downtime for replacement; 3. High system energy consumption: In order to compensate for insufficient adsorption efficiency and ensure that the nitrogen purity meets the standard, excessive compressed air (exceeding the theoretical air requirement) is required, which causes the air compressor to operate under high load for a long time, resulting in a significant increase in power consumption.

[0004] Therefore, optimizing the adsorption tower is key to improving the efficiency of the entire PSA nitrogen production system. Summary of the Invention

[0005] The purpose of this invention is to provide an adsorption tower for a pressure swing adsorption (PSA) nitrogen generation system, which can effectively improve the utilization rate of molecular sieves, extend the service life of molecular sieves, and enhance the overall efficiency of the PSA nitrogen generation system.

[0006] Another objective of this invention is to provide an energy-saving PSA nitrogen generation system containing the aforementioned adsorption tower.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: The first aspect of this utility model provides an adsorption tower for a pressure swing adsorption nitrogen generation system, comprising: The tower body has an air inlet at the bottom and an air outlet at the top. A multi-stage flow guiding mechanism includes a primary flow guide fixedly installed in the tower body, a secondary flow equalization plate arranged above the primary flow guide, and a buffer layer located above the secondary flow equalization plate. The primary flow guide is a conical plate structure with its tip facing the air inlet. The primary flow guide has several first through holes. The secondary flow equalization plate covers the primary flow guide and has several second through holes. The tertiary buffer layer is composed of inert packing material laid on the secondary flow equalization plate. The molecular sieve packing layer consists of molecular sieve packing laid on the three-stage buffer layer, wherein the particle size of the molecular sieve packing is smaller than that of the inert packing.

[0008] In this invention, a multi-stage flow guiding mechanism is installed inside the tower to guide the gas entering the tower from the inlet to the molecular sieve packing layer in multiple stages. The multi-stage flow guiding mechanism transforms the disordered gas intake into a uniform plunger flow, which significantly improves the utilization rate of the molecular sieve, reduces compressed air consumption, lowers system pressure and air compressor load, and has a significant overall energy-saving effect.

[0009] In some embodiments, the first through holes are distributed at intervals along the radial and circumferential directions of the primary flow guide, and the second through holes are distributed at intervals along the radial and circumferential directions of the secondary flow equalization plate.

[0010] Furthermore, the diameter of the first through hole increases from the center to the edge of the primary flow guide, and the diameter of the second through hole increases from the center to the edge of the secondary flow equalization plate.

[0011] In some embodiments, the cone angle of the tapered plate structure is 75° to 105°, for example, 75°, 80°, 85°, 90°, 95°, 100°, 105°.

[0012] In some embodiments, the sidewall of the primary flow guide is concave and arc-shaped, which provides better flow guidance.

[0013] In some embodiments, the inert filler has a spherical structure.

[0014] In some embodiments, the inert filler is alumina ceramic.

[0015] Specifically, the inert filler is a chemically inert and high-strength spherical filler, preferably alumina ceramic balls.

[0016] In some embodiments, the particle size of the inert filler is 3 to 8 times that of the molecular sieve filler, for example, 3 times, 3.5 times, 4 times, 4.5 times, 5 times, 5.5 times, 6 times, 6.5 times, 7 times, 7.5 times, or 8 times.

[0017] In some embodiments, the three-stage buffer layer is formed by filling inert fillers of different particle sizes in a graded manner from bottom to top, ensuring dense packing of the inert fillers.

[0018] In some embodiments, the gas outlet is located on the side wall of the tower body and above the molecular sieve packing layer.

[0019] In some embodiments, the air inlet, the primary flow guide, and the tower body are coaxial.

[0020] In some embodiments, the bottom inner wall of the tower body is a downwardly concave arc surface.

[0021] Specifically, the air inlet is located at the center of the bottom of the tower body, and the air outlet is located on the side wall of the upper part of the tower body, extending outward along the tangential direction.

[0022] In some embodiments, the adsorption tower further includes a molecular sieve clamping mechanism capable of applying downward pressure to the upper surface of the molecular packing layer.

[0023] The molecular sieve clamping mechanism is used to create continuous and uniform pressure constraint on the molecular sieve bed, suppressing vibration of the molecular sieve bed during the switching process of the adsorption tower from "adsorption (high pressure) to regeneration (low pressure)," reducing friction and collision between particles, and fundamentally reducing the probability of molecular sieve pulverization. Working in conjunction with the multi-stage flow guiding mechanism, it can effectively suppress molecular sieve pulverization, extend the service life of the molecular sieve, and significantly reduce user maintenance costs and downtime losses.

[0024] Furthermore, the molecular sieve pressing mechanism includes a pressure plate movably disposed within the tower body and located above the molecular sieve packing layer, and a driving device disposed on the tower body for driving the pressure plate to move in the vertical direction.

[0025] Furthermore, the pressure plate is provided with a plurality of honeycomb-shaped, evenly distributed third through holes, the diameter of which is 0.5 to 0.8 times the particle size of the molecular sieve. For example, 0.5, 0.6, 0.7, and 0.8 times. This ensures that nitrogen gas can pass through smoothly while preventing molecular sieve particles from leaking out, and at the same time, it evenly distributes the clamping force throughout the entire molecular sieve bed.

[0026] Furthermore, the pressure plate is a corrosion-resistant metal plate.

[0027] Furthermore, the driving device is a spring-driven device or a cylinder-driven device.

[0028] Furthermore, the molecular sieve clamping mechanism also includes a base fixedly disposed on the top of the tower body for fixing the drive device.

[0029] The second aspect of this utility model provides a pressure swing adsorption nitrogen generation system, which includes an air compressor, a refrigerated dryer, an air buffer tank, an adsorption tower, a nitrogen buffer tank, and a control system connected in sequence, wherein the adsorption tower is the aforementioned adsorption tower.

[0030] Specifically, the air compressor provides compressed air that meets the pressure requirements; the refrigerated dryer is connected to the air compressor outlet and cools the compressed air to the dew point temperature through refrigeration, condensing and removing most of the liquid moisture contained therein; the air buffer tank is located after the refrigerated dryer to stabilize the pressure and flow rate of the compressed air; the adsorption tower is connected downstream of the air buffer tank and consists of at least two towers that alternately perform adsorption and regeneration operations; the nitrogen buffer tank is located at the adsorption tower outlet to store nitrogen; and the control system is configured to dynamically adjust the switching sequence of the pneumatic valves according to the pressure drop changes of the adsorption tower.

[0031] Furthermore, the air compressor, refrigerated dryer, air buffer tank, adsorption tower, and nitrogen buffer tank are connected in sequence via pipelines.

[0032] Furthermore, the pipeline is equipped with several pneumatic valves and precision instruments, which are connected to the control system via electrical signals. The control system, as the central hub of the entire nitrogen generation system, precisely controls the entire nitrogen generation process through automatic monitoring, adjustment, and switching.

[0033] The pressure swing adsorption nitrogen generation system of this invention enables the adsorption and desorption regeneration process of the adsorption tower to be more complete and stable, thereby ensuring higher purity and smaller fluctuations in the produced nitrogen.

[0034] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art: The adsorption tower of this invention for a pressure swing adsorption (PSA) nitrogen generation system uses a multi-stage flow guiding mechanism with a special structure inside the tower to transform disordered air intake into uniform plunger flow, which significantly improves the utilization rate of molecular sieves, reduces compressed air consumption, and thus reduces the system pressure and air compressor load of the PSA nitrogen generation system. The overall energy-saving effect of the PSA nitrogen generation system using this adsorption tower is obvious. Attached Figure Description

[0035] Figure 1 This is a three-dimensional structural diagram of the adsorption tower in Example 1; Figure 2 This is a schematic diagram of the main cross-sectional structure of the adsorption tower in Example 1; Figure 3This is a three-dimensional structural diagram of the primary flow guide in the adsorption tower of Example 1; Figure 4 This is a schematic diagram of the planar structure of the secondary flow equalization plate in the adsorption tower of Example 1; Figure 5 This is a schematic diagram of the pressure swing adsorption nitrogen generation system in Example 2. In the attached diagrams above, 1 is an air compressor; 2 is a refrigerated dryer; 3 is an air buffer tank; 4a is a first adsorption tower; 4b is a second adsorption tower; 5 is a nitrogen buffer tank; and 6 is a control system. 41. Tower body; 411. Air inlet; 412. Air outlet; 413. End cap; 421. Primary flow guide; 4211. First through hole; 422. Secondary flow equalization plate; 4221. Secondary through hole; 423. Tertiary buffer layer; 4231. Inert packing; 43. Molecular sieve packing layer; 44. Molecular sieve clamping mechanism; 441. Cylinder drive device; 442. Pressure plate. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0037] In the description of this utility model, it should be understood that the use of directional terms such as "upper", "lower", "inner", "outer", "axial", "radial", and "circumferential" is only for the convenience of describing the embodiments of this utility model and simplifying the description, and does 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, it should not be construed as a limitation on the embodiments of this utility model.

[0038] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0039] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0040] Example 1: This example provides an adsorption tower for a pressure swing adsorption (PSA) nitrogen generation system. For example... Figures 1 to 4 As shown, the adsorption tower of this embodiment includes a tower body 41, a multi-stage flow guiding mechanism disposed within the tower body 41, a molecular sieve packing layer 43, and a molecular sieve pressing mechanism 44 disposed on the tower body 41.

[0041] Specifically, the tower body 41 is roughly cylindrical inside. The bottom inner wall of the tower body 41 is a downwardly concave arc surface. An air inlet 411 is provided at the center of the bottom. An air outlet 412 is provided on the upper side wall and extends outward from the side wall of the tower body 41 along the tangential direction. A cap 413 is provided at the top of the tower body 41.

[0042] Specifically, the multi-stage flow guiding mechanism includes a primary flow guide 421 fixedly installed in the tower body 41, a secondary flow equalization plate 422 arranged above the primary flow guide 421, and a buffer layer located above the secondary flow equalization plate 422. The primary flow guide 421 is a conical plate structure with its tip facing the air inlet 411. The primary flow guide 421 has several first through holes 4211. The secondary flow equalization plate 422 covers the primary flow guide 421. The secondary flow equalization plate 422 has several second through holes 4221. The tertiary buffer layer 423 is composed of inert packing 4231 laid on the secondary flow equalization plate 422. In this embodiment, the cone angle α of the conical plate structure is approximately 90°. The sidewall of the primary flow guide 421 is a concave arc surface. The first through holes 4211 are distributed sequentially at intervals along the radial and circumferential directions of the primary flow guide 421, and the diameter of the first through holes 4211 increases from the center to the edge of the primary flow guide 421. The secondary flow equalization plate 422 is a circular porous plate. The second through holes 4221 are distributed sequentially at intervals along the radial and circumferential directions of the secondary flow equalization plate 422, and the diameter of the second through holes 4221 increases from the center to the edge of the secondary flow equalization plate 422. The tertiary buffer layer 423 is composed of inert fillers 4231 of different particle sizes, which are filled in a graded manner with the particle size gradually decreasing from bottom to top to ensure dense packing of the inert fillers 4231. The inert fillers 4231 are alumina ceramic balls. The particle size of the inert fillers 4231 is 3 to 8 times that of the molecular sieve fillers. In this embodiment, the air inlet 411, the multi-stage flow guiding mechanism, and the tower body 41 are coaxial.

[0043] Specifically, the molecular sieve packing layer 43 is composed of molecular sieve packing material laid on the three-stage buffer layer 423, and the particle size of the molecular sieve packing material is smaller than that of the inert packing material 4231. The molecular sieve packing layer 43 is located below the gas outlet 412.

[0044] Specifically, the molecular sieve compaction mechanism 44 is configured to exert downward pressure on the upper surface of the molecular sieve packing layer to ensure tight compaction of the molecular sieve packing. In this embodiment, the molecular sieve compaction mechanism 44 includes a pressure plate 442 movably disposed within the tower body 41 and located above the molecular sieve packing layer 43, and a drive device disposed on the tower body 41 for driving the pressure plate 442 to move vertically. The pressure plate 442 is a corrosion-resistant metal plate with several honeycomb-shaped evenly distributed third through holes, the diameter of which is 0.5 times the molecular sieve particle size. A base for fixing and installing the drive device is fixedly disposed on the top of the tower body 41, and the drive device is a cylinder drive device 441.

[0045] Example 2: This example provides an energy-saving pressure swing adsorption nitrogen generation system using the adsorption tower of Example 1.

[0046] like Figure 5 As shown, the pressure swing adsorption (PSA) nitrogen generation system of this embodiment includes an air compressor 1, a refrigerated dryer 2, an air buffer tank 3, an adsorption tower, and a nitrogen buffer tank 5 connected in sequence via pipelines. The adsorption towers include a first adsorption tower 4a and a second adsorption tower 4b, both of which are adsorption towers from Embodiment 1. The PSA nitrogen generation system of this embodiment also includes a control system 6. Several pneumatic valves and precision instruments are installed on the pipelines, and the pneumatic valves and precision instruments are connected to the control system 6 via electrical signals.

[0047] In this embodiment, the compressed air generated by the air compressor 1 is cooled and dried by the refrigerated dryer 2 and purified by the precision filter before being stored in the air buffer tank 3. After being pressurized by the air buffer tank 3, the clean compressed air enters the adsorption tower, which is in the adsorption state, through a pneumatic valve assembly. The compressed air entering from the inlet 411 of the tower body 41 undergoes initial diffusion through the first-stage guide vane 421, fine flow equalization through the second-stage flow equalization plate 422, and final flow stabilization through the third-stage buffer layer 423, transforming into a uniform plunger flow. After contacting and adsorbing the molecular sieve packing, it is then discharged from the outlet 412. The product gas discharged from the adsorption tower is detected by a precision instrument; qualified nitrogen is sent to the nitrogen buffer tank 5, while unqualified nitrogen is discharged. Throughout the nitrogen production process, the molecular sieve pressing mechanism 44 continuously presses down, uniformly transmitting force to the entire molecular sieve bed to prevent it from loosening and pulverizing.

[0048] Furthermore, while the first adsorption tower 4a is in the adsorption state, the second adsorption tower 4b is regenerated through a series of steps including pressure equalization, pressure relief, and low-flow purging to desorb the adsorbed impurities. The entire nitrogen production process is automatically controlled by the control system 6, which uses a program to make the pneumatic valves work alternately at regular intervals, thereby achieving continuous nitrogen production.

[0049] The energy-saving pressure swing adsorption nitrogen generation system of this embodiment transforms disordered air intake into uniform plunger flow through a specially structured multi-stage flow guiding mechanism, achieving uniform airflow distribution, significantly improving the utilization rate of carbon molecular sieves and extending their service life. At the same time, through the synergistic effect of various components, it can produce nitrogen with more stable purity with lower compressed air consumption, reducing the workload of the air compressor. While ensuring high system performance and high reliability, it greatly improves the overall energy-saving effect of the system.

[0050] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. An adsorption tower for a pressure swing adsorption nitrogen generation system, characterized in that: It includes: The tower body (41) has an air inlet (411) at the bottom and an air outlet (412) at the top. A multi-stage flow guiding mechanism includes a primary flow guide (421) fixedly installed in the tower body (41), a secondary flow equalization plate (422) arranged above the primary flow guide (421), and a tertiary buffer layer (423) located above the secondary flow equalization plate (422). The primary flow guide (421) is a conical plate structure with its tip facing the air inlet (411). The primary flow guide (421) has several first through holes (4211). The secondary flow equalization plate (422) covers the primary flow guide (421). The secondary flow equalization plate (422) has several second through holes (4221). The tertiary buffer layer (423) is composed of inert packing (4231) laid on the secondary flow equalization plate (422). The molecular sieve packing layer (43) is composed of molecular sieve packing laid on the three-stage buffer layer (423), wherein the particle size of the molecular sieve packing is smaller than that of the inert packing (4231).

2. The adsorption tower for a pressure swing adsorption nitrogen generation system according to claim 1, characterized in that: The first through hole (4211) is distributed sequentially at intervals along the radial and circumferential directions of the first-stage flow guide (421), and the second through hole (4221) is distributed sequentially at intervals along the radial and circumferential directions of the second-stage flow equalization plate (422).

3. The adsorption tower for a pressure swing adsorption nitrogen generation system according to claim 2, characterized in that: The diameter of the first through hole (4211) increases from the center to the edge of the primary flow guide (421), and the diameter of the second through hole (4221) increases from the center to the edge of the secondary flow equalization plate (422).

4. The adsorption tower for a pressure swing adsorption nitrogen generation system according to claim 1, characterized in that: The cone angle (α) of the conical plate structure is 75°~105°; And / or, the sidewall of the primary flow guide (421) is concave arc-shaped.

5. The adsorption tower for a pressure swing adsorption nitrogen generation system according to claim 1, characterized in that: The inert filler (4231) has a spherical structure; And / or, the inert filler (4231) is alumina ceramic; And / or, the particle size of the inert packing (4231) is 3 to 8 times the particle size of the molecular sieve packing; And / or, the three-stage buffer layer (423) is formed by filling inert fillers (4231) of different particle sizes in a graded manner with the particle size gradually decreasing from bottom to top; And / or, the outlet (412) is located on the side wall of the tower body (41) and above the molecular sieve packing layer (43); And / or, the air inlet (411), the primary flow guide (421), and the tower body (41) are coaxial; And / or, the bottom inner wall of the tower body (41) is a downwardly concave arc surface.

6. The adsorption tower for a pressure swing adsorption nitrogen generation system according to any one of claims 1 to 5, characterized in that: It also includes a molecular sieve clamping mechanism (44) capable of generating downward pressure on the upper surface of the molecular sieve packing layer.

7. The adsorption tower for a pressure swing adsorption nitrogen generation system according to claim 6, characterized in that: The molecular sieve pressing mechanism (44) includes a pressure plate (442) movably disposed within the tower body (41) and located above the molecular sieve packing layer (43), and a driving device disposed on the tower body (41) for driving the pressure plate (442) to move in the up and down direction.

8. The adsorption tower for a pressure swing adsorption nitrogen generation system according to claim 7, characterized in that: The pressure plate (442) has several honeycomb-shaped, evenly distributed third through holes, the diameter of which is 0.5 to 0.8 times the particle size of the molecular sieve.

9. The adsorption tower for a pressure swing adsorption nitrogen generation system according to claim 7, characterized in that: The driving device is a spring driving device or a cylinder driving device (441).

10. A pressure swing adsorption (PSA) nitrogen generation system, comprising an air compressor (1), a refrigerated dryer (2), an air buffer tank (3), an adsorption tower, a nitrogen buffer tank (5), and optionally a control system (6), connected in sequence, characterized in that, The adsorption tower is the adsorption tower according to any one of claims 1 to 9.

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