A liquid collection and redistribution device for a bundled rectification column

Abstract

The application provides a liquid collecting and redistributing device for a bundled rectifying tower, comprising a liquid collecting disc, the liquid collecting disc being provided with a gas passage hole and a liquid downflow hole, the gas passage hole being provided with a gas lift cover for passing a gas phase, and the liquid downflow hole being provided with a liquid downflow pipe for guiding a liquid phase; a liquid collecting separator is arranged at the lower part of the liquid collecting disc; the application realizes extremely high liquid distribution uniformity and collection rate: through the two-stage design of the liquid collecting disc and the liquid collecting separator, and the arrangement of an independent liquid collecting separator for each liquid downflow pipe, point-to-point rigid distribution of the liquid is realized; the structure ensures that the liquid flowing from the upper layer of packing is 100% collected and distributed to each specified liquid redistributing pipe without segregation, and is finally accurately introduced into the corresponding bundled rectifying pipe, so that the liquid amount deviation between the pipes is fundamentally eliminated, the mass transfer efficiency is greatly improved, and the application is particularly suitable for low liquid amount working conditions.

Description

Technical Field

[0001] This application relates to the field of chemical technology, specifically to a liquid collection and redistribution device for a cluster distillation column. Background Technology

[0002] Distillation, as the core liquid-liquid separation unit operation in modern industry, directly determines the production cost and product quality of many industries such as chemical, petroleum, and pharmaceutical. The internal components of the distillation column, as the heart of the column, play a decisive role in the separation effect. Among them, the liquid collection and redistribution device is particularly critical. It is responsible for collecting the liquid flowing down from the upper packing and redistributing it evenly to the lower packing bed to eliminate phenomena such as liquid deviation and channeling caused by the column wall effect, the characteristics of the packing itself, or uneven initial distribution, thereby maximizing the mass transfer efficiency of the packing.

[0003] With the development of industries such as precision chemicals, high-end reagent purification, and electronic chemicals, the requirements for product purity are approaching their limits. Bundled distillation technology has been widely used because it can achieve extremely high theoretical plate numbers and extremely narrow product fractions. This technology typically divides a large-diameter distillation column into multiple parallel, small-diameter distillation tubes (i.e., bundled tubes), thereby effectively suppressing gas-phase backmixing and improving overall separation accuracy. However, this special structure also poses unprecedented challenges to the column internals. The following are common problems that may arise under various conditions: 1. Extreme operating conditions: Bundle distillation often serves the fractionation of high-value-added materials. These systems are highly heat-sensitive and require operation under high vacuum and low liquid load. Low-boiling-point materials have a large gas volume under low pressure, but the liquid flow rate is extremely small. This contradiction makes the effective collection and redistribution of liquid extremely difficult. Traditional distributors such as pipe-type and tray-type are prone to problems such as incomplete liquid collection, poor dripping at the distribution orifice, or even flow interruption under these conditions, resulting in some packing material drying out and some being submerged, and the separation efficiency dropping sharply. 2. Extremely high requirement for uniformity of distribution: The efficiency of bundled distillation is based on the completely consistent gas-liquid load of each parallel distillation tube. If the liquid redistributor cannot ensure that the liquid volume obtained by each bundle tube is absolutely uniform, the separation efficiency between the tubes will be different, resulting in short-circuit effect or hysteresis effect. Ultimately, the purity of the product will be contaminated by the inefficient tube stream when it is mixed at the outlet, making the design advantages of the bundled structure disappear. Existing redistributors are difficult to meet this one-to-one precise distribution requirement. 3. Strict gas phase pressure drop limitation: The total pressure drop resource of a high vacuum system is extremely valuable. Any additional resistance introduced by any internal components of the tower means a significant increase in energy consumption or even failure of the vacuum system. The gas phase channel design of traditional redistributors is often not optimized for low pressure drop, and the gas rise structure is complex or the opening ratio is insufficient, which becomes the bottleneck of system energy consumption.

[0004] In summary, existing traditional liquid collection and redistribution devices struggle to balance liquid collection rate, distribution uniformity, and low gas phase resistance when dealing with extreme conditions such as cluster distillation, characterized by low liquid volume, high vacuum, and high distribution precision. This presents a significant technical shortcoming. Therefore, there is an urgent need for an innovative, dedicated redistribution device capable of simultaneously addressing these issues, ensuring stable and efficient operation of the cluster distillation column, and achieving its theoretically superior separation performance. After a thorough search, the applicant has not found any relevant technical solutions.

[0005] Therefore, a new technical solution is needed to solve the above-mentioned technical problems. Utility Model Content

[0006] This application provides a liquid collection and redistribution device for a cluster distillation column, including a liquid collection tray with a vent hole and a downcomer hole. The vent hole is equipped with a gas riser for passing gas phase, and the downcomer hole is equipped with a downcomer pipe for guiding liquid phase. A liquid separator is provided at the lower part of the liquid collection tray.

[0007] As a preferred embodiment, the liquid separator includes a liquid collecting plate disposed below a liquid collecting plate, an upwardly extending sleeve 1 disposed above the liquid collecting plate, a downcomer extending into the sleeve 1, and a downwardly extending sleeve 2 disposed below the liquid collecting plate, the sleeve 2 having multiple small gas phase holes on its wall; at least three liquid redistribution pipes are fixedly disposed on the liquid collecting plate, the liquid redistribution pipes extending upward into the sleeve 1 and downward into the sleeve 2.

[0008] As a preferred embodiment, there is a gap between the top of the sleeve and the bottom of the liquid collection tray.

[0009] As a preferred embodiment, the downcomer has multiple downcomer inlet holes on its side wall.

[0010] As a preferred embodiment, the liquid redistribution pipe has multiple distribution pipe inlet holes on its side wall.

[0011] As a preferred embodiment, the air hood includes an air riser pipe, which is fixed to the liquid collection tray and corresponds to the position of the vent hole. A conical cap is fixed to the top of the air riser pipe.

[0012] As a preferred embodiment, the bottom of the second sleeve is provided with a tapered groove.

[0013] As a preferred embodiment, the number of downcomers and liquid collectors is equal, and the number of liquid collectors is consistent with the number of distillation tubes in the bundled distillation column, with each liquid collector corresponding to one distillation tube.

[0014] As a preferred embodiment, a liquid collection and redistribution device for a bundled distillation column is applied between every two packing bed layers of the bundled distillation column.

[0015] This application has the following advantages: 1. Achieves extremely high liquid distribution uniformity and collection rate: Through the two-stage design of liquid collection tray and liquid separator, and with an independent liquid separator for each downcomer, point-to-point rigid distribution of liquid is achieved; this structure ensures that the liquid flowing down from the upper packing layer is 100% collected and distributed without segregation to each designated liquid redistribution pipe, and finally accurately introduced into the corresponding bundled distillation pipe, fundamentally eliminating the liquid volume deviation between each pipe, greatly improving the mass transfer efficiency, and is particularly suitable for low liquid volume conditions.

[0016] 2. Extremely low pressure drop in the gas phase channel and good system stability: The structure with multiple small gas phase holes in the inner wall of the sleeve serves as the main gas phase channel. This design greatly increases the gas phase flow area, allowing the gas phase to pass through uniformly and dispersedly at a low flow rate. This effectively avoids the local eddies and throttling effects present in traditional riser pipe structures, thereby minimizing the pressure drop caused by the redistributor to the system. This is very beneficial for maintaining the stable operation of the high vacuum distillation system and reducing energy consumption.

[0017] 3. Compact structure, good sealing and guiding performance, and convenient installation: The conical groove at the bottom of the liquid separator and the bundled distillation tube are assembled with a socket, which not only ensures the accuracy and convenience of installation and positioning, but also forms a good sealing structure. It can effectively prevent gas phase short circuit and ensure that all rising gas phase must pass through the small hole on the sleeve, thereby ensuring the expected gas-liquid distribution effect. The whole device has a high degree of modularity and is naturally compatible with the multi-tube structure of the bundled tower.

[0018] 4. Strong anti-clogging capability and high operational flexibility: The liquid flow path consists of a downcomer, a collection tray, and a distribution pipe, while the gas phase path consists of a sleeve orifice and a gas riser. The liquid flow path and the gas phase path are independent of each other and have a simple and smooth structure, which reduces the risk of clogging caused by material polymerization or crystallization. At the same time, the ample gas-liquid channel design enables the device to maintain good distribution performance under different operating loads, with high operational flexibility and a wide range of applications.

[0019] 5. Improved overall performance and significant economic benefits: This utility model, through ingenious configuration design, simultaneously and optimally solves the two core contradictions of uneven liquid distribution and large pressure drop in high vacuum and low liquid volume bundled distillation; its application can significantly improve product purity, recovery rate and tower processing capacity, while reducing energy consumption and operating costs, resulting in significant comprehensive economic benefits. Attached Figure Description

[0020] Figure 1 This is a structural schematic diagram from one angle of this application; Figure 2 This is a structural schematic diagram from angle two of this application; Figure 3 This is a schematic diagram of the liquid separator at angle one of this application; Figure 4 This is a schematic diagram of the liquid separator at angle two of this application; Figure 5 This is a schematic diagram of the liquid separator at angle three of this application; Figure 6 This is a structural schematic diagram of the air hood and liquid collection plate at one angle; Figure 7 This is a structural schematic diagram of the air hood and liquid collection plate at angle two; Figure 8 This is an exploded view of the application scenario of this application; Figure 9 This is a schematic diagram of a partial bundled distillation column; 1. Liquid collection tray; 2. Downcomer; 3. Gas riser; 4. Downcomer pipe; 5. Gas riser pipe; 6. Conical cap; 7. Liquid separator; 8. Liquid collection tray; 9. Sleeve 1; 10. Sleeve 2; 11. Gas phase orifice; 12. Liquid redistribution pipe; 13. Bundled distillation column; 14. Conical trough; 15. Distillation tube. Detailed Implementation

[0021] The following is in conjunction with the appendix Figure 1 , Figure 2 The specific embodiments of this utility model will be described in detail below. It should be noted that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model. Example 1

[0022] This embodiment provides a liquid collection and redistribution device for a bundled distillation column, including a liquid collection tray 1. The liquid collection tray 1 has a vent hole and a downcomer hole 2. A gas riser 3 for passing gas phase is installed on the vent hole, and a downcomer pipe 4 for guiding liquid phase is installed on the downcomer hole 2. The gas riser 3 includes a vertically arranged gas riser pipe 5, which is fixed to the liquid collection tray 1 and corresponds to the position of the vent hole. A conical cap 6 is fixed to the top of the gas riser pipe 5 by welding or other means. A gap exists between the top of the riser pipe 5 and the riser pipe 5. The riser pipe 5 is designed to guide the lower gas phase to pass uniformly through the liquid collection tray 1. The cone cap 6 effectively prevents liquid from entering the riser pipe 5, which serves as a gas phase channel. Preferably, the downcomer pipe 4 is arranged around or adjacent to the riser hood 3. Liquid falling from the upper packing section is collected by the liquid collection tray 1 and flows into the downcomer pipe 4 through the top of the downcomer pipe 4. The riser hood 3, the downcomer pipe 4, and the liquid collection tray 1 are sealed together by welding or other means. The lower part of the liquid collection tray 1... The unit is equipped with a liquid collector 7; specifically, the liquid collector 7 includes a horizontally arranged liquid collection plate 8 located below the liquid collection plate 1, with an upwardly extending sleeve 9 installed on the upper part of the liquid collection plate 8, and a downcomer 4 extending into the sleeve 9. There is a gap between the top of the sleeve 9 and the bottom of the liquid collection plate 1 to facilitate the rise of the gas phase; a downwardly extending sleeve 10 is installed at the lower part of the liquid collection plate 8, and multiple small gas phase holes 11 are opened on the wall of the sleeve 10; the liquid collection plate 8 is vertically fixed... There are at least three liquid redistribution pipes 12, which are connected to the collection tray 8 by welding or other means. The liquid redistribution pipes 12 extend upward into the sleeve 1 9, ensuring that they do not interfere with the downcomer 4 extending into the sleeve 1 9, and extend downward into the sleeve 2 10. The collection tray 8 is used to receive the liquid flowing out from the downcomer 4 and distribute it to each liquid redistribution pipe 12. The outlet of the liquid redistribution pipe 12 extends downward into the sleeve 2 10 and corresponds to the packing bed above the bundled distillation column 13.

[0023] Preferably, to facilitate the flow of the liquid phase, a downcomer inlet hole (not shown in the figure) is provided on the side wall of the downcomer 4. One or more downcomer inlets can be provided, which are evenly distributed along the circumference and axial direction of the downcomer 4. Multiple distribution pipe inlets (not shown in the figure) are provided on the side wall of the liquid redistribution pipe 12. The distribution pipe inlets are evenly distributed along the circumference and axial direction of the cylinder wall of the liquid redistribution pipe 12. When the downcomer inlet hole is provided, the liquid falling from the upper packing section is received by the liquid collection plate 1 and flows into the downcomer 4 through the downcomer inlet hole. When the distribution pipe inlet hole is provided, the liquid flowing into the collection plate 8 from the downcomer 4 enters the liquid redistribution pipe 12 through the distribution pipe inlet hole.

[0024] Preferably, the bottom of the sleeve 10 is provided with a conical groove 14; the conical groove 14 is used to fit into the port of the distillation tube 15 of the bundled distillation column 13; the number of downcomers 4 and liquid collectors 7 is equal, and the number of liquid collectors 7 is consistent with the number of distillation tubes 15 of the bundled distillation column 13, with each liquid collector 7 corresponding to one distillation tube 15; the above-mentioned liquid collection and redistribution device for a bundled distillation column is applied between every two packing bed layers of the bundled distillation column 13.

[0025] Liquid from the upper downcomer 4 first falls into the collection tray 8, and then is distributed to each liquid redistribution pipe 12. Each liquid redistribution pipe 12 is evenly arranged, and its outlet end is located directly above the packing bed in the lower cluster distillation column 13, which can evenly drip or spray the liquid onto the packing surface. The gas phase at the bottom of the column flows out from the gas phase orifice 11 and enters the upper packing section through the riser pipe 5. In this embodiment, the liquid phase is collected by the liquid collection tray 1, guided by the downcomer 4, distributed by the collection tray 8, and sprayed by the liquid redistribution pipe 12 to achieve a balanced liquid volume in each distillation tube 15. The gas phase is converged through the gas phase orifice 11 and guided by the riser hood 3 to achieve a low-resistance and uniform rise. This device ultimately achieves uniform distribution and efficient mass transfer of the gas and liquid phases above each packing layer. Example 2

[0026] This embodiment provides a specific application scenario: Take, for example, a liquid collection and redistribution device for a bundled distillation column 13 with a diameter of DN800, which contains 7 parallel DN200 distillation tubes 15.

[0027] Column body and operating conditions: The bundled distillation column 13 operates in a high vacuum environment with an absolute pressure of 5 kPa and is used to separate heat-sensitive organic materials. The liquid phase load is extremely low, about 1-0.5 m³ / h. Installation location: This liquid collection and redistribution device is installed between the upper and lower layers of structured packing inside the tower, approximately 300 mm from the upper surface of the lower packing layer; Liquid collection tray 1: Made of 316L stainless steel plate with a thickness of 3mm, the whole is a circular tray, which is fixed to the support ring on the tower wall by the support bracket or by the equipment flange support structure. The liquid collection tray 1 is equipped with 7 DN20 downcomers 4, which correspond one-to-one with the positions of 7 distillation tubes 15; Six sets of DN200 air hoods 3 are installed on the liquid collection tray 1. Each air hood 3 consists of an air hood 5 with a diameter of DN200 and a standard cone cap 6 welded to its top. The air hood 5 is fixed to the liquid collection tray 1 by welding. The downcomer 4 is a short pipe with a diameter of DN20 and a length of about 200mm. It is arranged around the air hood 3. The top of the downcomer 4 is closed. On its upper side wall, within 10mm from the top, there is an overflow hole with a diameter of 8mm and a downcomer inlet hole with a diameter of 4mm. Liquid collector 7: In this embodiment, a total of 7 liquid collectors 7 are provided, each facing the lower outlet of a downcomer 4 and corresponding to a distillation tube 15; more specifically: Liquid collection tray 8: A circular plate with a diameter of DN200, used to receive liquid from the upper downcomer 4; Liquid redistribution pipe 12: 3 stainless steel pipes with a diameter of DN20 are vertically welded to the bottom of the liquid collection tray 8 and are evenly distributed in an equilateral triangle; the length of the liquid redistribution pipe 12 extends to about 100mm above the lower packing bed. Sleeve 1 9 and Sleeve 2 10 are cylindrical tubes with a diameter of DN200. The lower end of Sleeve 1 9 is sealed and welded to the liquid collection plate 8, and the upper end of Sleeve 2 10 is sealed and welded to the liquid collection plate 8. On the lower part of the cylinder wall of Sleeve 2 10, four rows of 12 gas phase holes 11 with a diameter of 8mm are evenly drilled along the circumference. The total opening area is much larger than the cross-sectional area of ​​the gas riser pipe 5 to ensure low pressure drop.

[0028] Conical groove 14: The lowermost end of sleeve 2 10 is designed as a conical structure, the size of which matches the chamfer of the DN200 distillation tube 15 opening; during installation, the entire liquid collector 7 is placed on the distillation tube 15 opening through this conical groove 14 to achieve rapid centering.

[0029] The working process of this embodiment is as follows: Liquid flow: The liquid flowing down from the upper packing is collected by the liquid collection tray 1, enters the downcomer 4 through the downcomer inlet hole on the side wall of the downcomer 4, and flows into the collection tray 8 of the liquid separator 7 directly below by gravity. After the liquid briefly gathers in the collection tray 8, it is evenly distributed to the three liquid redistribution pipes 12, and finally evenly sprinkled on the surface of the lower packing bed in the form of drops. Gas flow: The gas phase at the bottom of the tower flows out from the gas phase hole 11 on the side wall of sleeve 2 10, and then flows upward through the gas riser 3 of the liquid collection plate 1 and enters the upper packing section.

[0030] In this embodiment, the device operates stably and performs excellently under high vacuum and low liquid volume conditions. Measurements show that the relative deviation of liquid distribution between each distillation tube is less than 5%, which fully meets the process requirements of high-purity distillation. At the same time, the vapor pressure drop caused by the device is less than 50 Pa, and its impact on the vacuum level of the entire system is negligible.

[0031] In summary, due to the adoption of the above-mentioned technology, this application has the following advantages: 1. Achieves extremely high liquid distribution uniformity and collection rate: Through the two-stage design of liquid collection tray and liquid separator, and with an independent liquid separator for each downcomer, point-to-point rigid distribution of liquid is achieved; this structure ensures that the liquid flowing down from the upper packing layer is 100% collected and distributed without segregation to each designated liquid redistribution pipe, and finally accurately introduced into the corresponding bundled distillation pipe, fundamentally eliminating the liquid volume deviation between each pipe, greatly improving the mass transfer efficiency, and is particularly suitable for low liquid volume conditions.

[0032] 2. Extremely low pressure drop in the gas phase channel and good system stability: The structure with multiple small gas phase holes in the inner wall of the sleeve serves as the main gas phase channel. This design greatly increases the gas phase flow area, allowing the gas phase to pass through uniformly and dispersedly at a low flow rate. This effectively avoids the local eddies and throttling effects present in traditional riser pipe structures, thereby minimizing the pressure drop caused by the redistributor to the system. This is very beneficial for maintaining the stable operation of the high vacuum distillation system and reducing energy consumption.

[0033] 3. Compact structure, good sealing and guiding performance, and convenient installation: The conical groove at the bottom of the liquid separator and the bundled distillation tube are assembled with a socket, which not only ensures the accuracy and convenience of installation and positioning, but also forms a good sealing structure. It can effectively prevent gas phase short circuit and ensure that all rising gas phase must pass through the small hole on the sleeve, thereby ensuring the expected gas-liquid distribution effect. The whole device has a high degree of modularity and is naturally compatible with the multi-tube structure of the bundled tower.

[0034] 4. Strong anti-clogging capability and high operational flexibility: The liquid flow path consists of a downcomer, a collection tray, and a distribution pipe, while the gas phase path consists of a sleeve orifice and a gas riser. The liquid flow path and the gas phase path are independent of each other and have a simple and smooth structure, which reduces the risk of clogging caused by material polymerization or crystallization. At the same time, the ample gas-liquid channel design enables the device to maintain good distribution performance under different operating loads, with high operational flexibility and a wide range of applications.

[0035] 5. Improved overall performance and significant economic benefits: This utility model, through ingenious configuration design, simultaneously and optimally solves the two core contradictions of uneven liquid distribution and large pressure drop in high vacuum and low liquid volume bundled distillation; its application can significantly improve product purity, recovery rate and tower processing capacity, while reducing energy consumption and operating costs, resulting in significant comprehensive economic benefits.

[0036] The devices and connections not specifically described above are all existing technologies, and will not be described in detail here.

[0037] The preferred embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0038] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the various possible combinations in this application will not be described separately.

[0039] Furthermore, various different implementations of this application can be combined in any way, as long as they do not violate the spirit of this application, and such combinations should also be regarded as the content disclosed in this application.

Claims

1. A liquid collection and redistribution device for a bundled distillation column, comprising a liquid collection tray (1), characterized in that, The liquid collection tray (1) is provided with a vent hole and a liquid downhole hole (2). A gas lift hood (3) for passing gas phase is installed on the vent hole, and a liquid downhole pipe (4) for guiding liquid phase is installed on the liquid downhole hole (2). A liquid collector separator (7) is provided at the lower part of the liquid collection tray (1).

2. The liquid collection and redistribution device for a bundled distillation column according to claim 1, characterized in that, The liquid separator (7) includes a liquid collection plate (8) located at the bottom of the liquid collection plate (1), an upwardly extending sleeve (9) located at the top of the liquid collection plate (8), a downcomer (4) extending into the sleeve (9), a downwardly extending sleeve (10) located at the bottom of the liquid collection plate (8), and a plurality of gas phase holes (11) opened on the wall of the sleeve (10); at least three liquid redistribution pipes (12) are fixedly installed on the liquid collection plate (8), the liquid redistribution pipes (12) extending upward into the sleeve (9) and downward into the sleeve (10).

3. A liquid collection and redistribution device for a bundled distillation column according to claim 2, characterized in that, The bottom of the sleeve 2 (10) is provided with a conical groove (14).

4. A liquid collection and redistribution device for a bundled distillation column according to claim 2, characterized in that, There is a gap between the top of the sleeve (9) and the bottom of the liquid collection tray (1).

5. A liquid collection and redistribution device for a bundled distillation column according to claim 1, characterized in that, The downcomer (4) has a downcomer inlet hole on its side wall.

6. A liquid collection and redistribution device for a bundled distillation column according to claim 2, characterized in that, The liquid redistribution pipe (12) has multiple distribution pipe inlet holes on its side wall.

7. A liquid collection and redistribution device for a bundled distillation column according to claim 1, characterized in that, The air hood (3) includes an air hood (5), which is fixed to the liquid collection tray (1) and corresponds to the position of the vent hole. A cone cap (6) is fixed to the top of the air hood (5), and there is a gap between the cone cap (6) and the top of the air hood (5).

8. A liquid collection and redistribution device for a bundled distillation column according to claim 1, characterized in that, The number of downcomers (4) and liquid collectors (7) is equal. The number of liquid collectors (7) is the same as the number of distillation tubes (15) of the bundled distillation column (13). Each liquid collector (7) corresponds to one distillation tube (15).

9. A liquid collection and redistribution device for a bundled distillation column according to claim 1, characterized in that, The liquid collection and redistribution device is applied between every two packing beds of the cluster distillation column (13).

Images