Rectification column for crude alcohol separation

Abstract

The present application relates to rectification technical field, specifically to a kind of rectification tower for crude alcohol separation, including at least two series pressure separation parts, each pressure separation part at least includes one low-pressure column and one high-pressure column;Low-pressure column in each pressure separation part is connected with first splitter in overhead vapor phase extraction line, one outlet of first splitter is connected with the overhead condenser of low-pressure column and is used for reflux, another outlet is communicated with the feed pipe of high-pressure column in the pressure separation part of first pressurizing pump, the overhead vapor phase extraction line of high-pressure column is connected with second splitter, one outlet of second splitter is connected with the overhead condenser of high-pressure column, another outlet is communicated with the feed pipe of low-pressure column in the pressure separation part of pressure reducing valve;The bottom liquid phase extraction line of low-pressure column in first pressure separation part is connected with the feed pipe of low-pressure column in second pressure separation part.This application can improve the energy-saving effect of pressure rectification while ensuring the stability of rectification tower, improve rectification efficiency.

Description

Technical Field

[0001] This invention relates to the field of distillation technology, and more specifically to a distillation column for crude alcohol separation. Background Technology

[0002] Crude methanol is a mixture of methanol directly produced by methanol synthesis units without refining (referred to as crude alcohol). Crude alcohol is an important organic chemical raw material, and in addition to methanol, the product also contains water, acetaldehyde, propionaldehyde, acetone, methyl ethyl ketone, etc.

[0003] To ensure the effective utilization of crude alcohol, it is first dehydrated through a liquid-phase membrane to reduce the water content to below 1%. The remaining components are then separated by a dehydrogenation distillation column to remove light components such as acetaldehyde and propionaldehyde, and methanol with a purity of 99.7% is used for hydrogen production. Other components are enriched with acetone with a purity of over 85% for the production of isopropylamine. Finally, the remaining residue enters a catalytic unit for harmless utilization, and the heat generated is used to produce steam.

[0004] However, because methanol and acetone, as well as methanol and butanone, can form azeotropes, it is difficult to collect components with high purity. Jiang Bin et al.: Research progress on the separation of methanol-acetone azeotropes, Chemical Industry Progress, Vol. 29, No. 3, 2010, and Shi Chen et al.: Steady-state and dynamic simulation of methanol-acetone azeotropic separation process, Natural Gas Chemical Industry - C1 Chemistry and Chemical Engineering, Vol. 44, 2019, have both studied the separation of methanol and acetone.

[0005] Meanwhile, the patent document with application number CN201410368125.X also discloses an energy-saving process for separating methanol-acetone azeotropes by pressure swing distillation, which uses a process of connecting a vacuum distillation column with an intermediate reboiler and a pressurized distillation column in series for pressure swing distillation.

[0006] However, after acetone is collected from the bottom of the pressurized distillation column, the amount of liquid collected from the top of the column is reduced, and the efficiency of providing heat to the intermediate reboiler of the vacuum distillation column after condensation is very low.

[0007] Therefore, the present invention improves the pressure swing distillation device, thereby enhancing its energy-saving effect and increasing distillation efficiency. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a distillation column for crude alcohol separation, aiming to enhance the energy-saving effect of pressure swing distillation while ensuring stable distillation operation and improving distillation efficiency.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows:

[0010] A distillation column for crude alcohol separation includes at least two pressure swing separation sections connected in series, each pressure swing separation section including at least one low-pressure column and one high-pressure column;

[0011] The "low pressure" in the low-pressure tower refers to normal pressure or negative pressure, while the "high pressure" in the high-pressure tower refers to positive pressure. That is, in this invention, the "low pressure" in the low-pressure tower is relative to the pressure in the high-pressure tower, and the "high pressure" in the high-pressure tower is relative to the pressure in the low-pressure tower.

[0012] The gas phase exit pipeline at the top of the low-pressure tower in each of the aforementioned pressure-switching separation sections is connected to a first distributor. One outlet of the first distributor is connected to the top condenser of the low-pressure tower and used for reflux, while the other outlet is connected to the feed pipeline of the high-pressure tower in the same pressure-switching separation section via a first pressurizing pump. The gas phase exit pipeline at the top of the high-pressure tower is connected to a second distributor. One outlet of the second distributor is connected to the top condenser of the high-pressure tower, while the other outlet is connected to the feed pipeline of the low-pressure tower in the same pressure-switching separation section via a pressure reducing valve.

[0013] The two pressure-switching separation sections are the first pressure-switching separation section and the second pressure-switching separation section. The bottom liquid phase collection pipeline of the low-pressure tower in the first pressure-switching separation section is connected to the third distributor. One outlet of the third distributor is connected to the reboiler of the low-pressure tower in the first pressure-switching separation section, and the other outlet is connected to the feed pipeline of the high-pressure tower in the second pressure-switching separation section via the second pressurizing pump, thus forming two pressure-switching separation sections connected in series.

[0014] The initial distillation of the first pressure-switching separation section is fed by the low-pressure tower, while the initial distillation of the second pressure-switching separation section is fed by the high-pressure tower.

[0015] This structure allows the gas phase from the high-pressure tower, except for the reflux portion, to be directly fed to the low-pressure tower for replenishment without condensation. This reduces condensation energy consumption and the energy consumption of the low-pressure tower reboiler. Furthermore, since the gas phase is uncondensed and at a high temperature, it can provide more heat to the low-pressure tower, reducing the load on the reboiler. At the same time, the gas phase feed can improve mass transfer efficiency and distillation efficiency.

[0016] Furthermore, the low-pressure tower has a tower plate, on which a riser pipe is provided. A bubble cover is provided outside the riser pipe. The bubble cover has a toothed slit array that is lower than the upper outlet of the riser pipe. The bubble cover is slidably connected to the riser pipe. When the bubble cover slides to the highest position relative to the riser pipe, the toothed slit is flush with the upper outlet of the riser pipe.

[0017] Although vapor-phase feed offers significant energy-saving advantages for low-pressure distillation columns, it is prone to pressure fluctuations. These fluctuations affect product purity, yield, and column equilibrium, particularly in the rectification section. Larger pressure fluctuations can easily lead to flooding, and these fluctuations cannot be promptly adjusted manually. This technical solution addresses these issues by moving the bubble cap vertically relative to the riser. When the vapor pressure below the tray is high, the bubble cap moves upward relative to the riser, reducing the distance between the outlet and the toothed section. This minimizes the gas flow path and pressure drop, allowing the pressure below the tray to quickly transfer to the space above, eliminating vapor pressure fluctuations and preventing flooding in the downcomer due to delayed vapor pressure transfer.

[0018] Furthermore, the riser pipe is a circular tube with a baffle in the middle. The riser pipe below the baffle has at least one air outlet, and the riser pipe above the baffle has at least one vent hole. The bubble cover includes a sliding sleeve and a cover. The inner diameter of the cover is larger than the outer diameter of the riser pipe. The toothed slits are located at the lower part of the cover. The upper end of the cover is connected to the sliding sleeve. The sliding sleeve slides in contact with the outer wall of the riser pipe and covers the vent hole.

[0019] This structure not only enables the bubble cap to slide as the pressure below the tray changes, quickly eliminating pressure fluctuations, but also increases the venting height after the sliding sleeve slides relative to the riser pipe. This allows excess gas flow to pass directly upwards from the sliding sleeve, bypassing the gas-liquid contact area, without participating in the gas-liquid contact on the tray. This prevents the liquid phase on the tray from being entrained on the next tray due to excessive gas-liquid contact, thus avoiding gas entrainment and flooding.

[0020] When the gas pressure below the tray suddenly increases, the pressure pushes the bubble cap upward through the airflow in the riser pipe, causing the bubble cap to rise. The vent hole is mainly used to allow the airflow in the outlet to be discharged when the bubble cap rises to the point where it connects with the cover. This part of the airflow goes directly to the gas phase above the tray through the upper part of the riser pipe and the sliding sleeve, without participating in gas-liquid mixing. Because when the pressure below the tray suddenly increases, the gas velocity in the riser pipe increases, and the gas velocity passing through the tooth gap also increases, which itself enhances the gas-liquid mixing above the tray. This invention discharges the excess airflow through the vent hole, avoiding foam entrainment caused by excessive gas-liquid mixing, and ensuring stable equipment operation.

[0021] Furthermore, the upper end of the outer wall of the riser pipe is provided with a limiting ring, and the inner wall of the sliding sleeve is provided with a limiting groove. When the cover moves close to the upper end of the riser pipe, the limiting ring limits the bubble cover. The sliding sleeve is provided with a drain hole that connects to the lower end of the limiting groove, and the riser pipe is provided with a drain hole located on the upper side of the partition.

[0022] This technical solution mainly solves the problems of limited sliding sleeve stroke and easy liquid accumulation in the upper part of long gas pipes due to the opening at the upper end. The area above the tray is a strong gas-liquid contact zone, where the liquid phase is strongly disturbed and stirred by the gas phase. It is easy for the liquid to fall into the upper part of the riser pipe during splashing and generate liquid accumulation. This makes it difficult for the gas and liquid to flow quickly when the gas phase pressure fluctuates. The drain hole of this invention can drain the accumulated liquid, keep the upper part of the riser pipe open, and facilitate the rapid elimination of pressure fluctuations.

[0023] Furthermore, the width of the vent hole gradually increases from bottom to top.

[0024] Preferably, the vent hole is a triangular hole with the tip pointing downwards.

[0025] As the sliding sleeve rises, the cross-section of the inverted triangular vent hole that connects with the cover gradually increases, which helps to ensure the slow sliding of the blister. The slow sliding of the blister can effectively and smoothly eliminate pressure fluctuations.

[0026] Furthermore, each of the toothed slots is provided with an inclined guide plate on its outer side, and the guide plate forms an angle with the radial direction of the cover.

[0027] The guide plate rotates as the gas flow exits the riser pipe, causing the casing to disturb the surrounding liquid phase and eliminate the dead zone of the liquid phase above the tray.

[0028] Furthermore, the riser pipe is snapped into the tower plate, the lower end of the outer wall of the riser pipe is provided with a guide groove, the tower plate is provided with an installation hole for the riser pipe to pass through, the installation hole is provided with a flange extending into the guide groove, the outer wall of the riser pipe above and below the guide groove is provided with threads, and the riser pipe is fixed to the tower plate by a nut.

[0029] The above structure enables the riser pipe to be stably connected to the tower plate, and the bubble cap structure of the present invention makes connection and disassembly convenient and prevents it from falling off.

[0030] Furthermore, the tray is provided with a flow guide plate, which causes the liquid phase on the tray to flow in a continuous "S" shape.

[0031] The continuous "S"-shaped flow of liquid phase can come into contact with the bubble cap more times, resulting in more efficient gas-liquid mass transfer and improved distillation efficiency.

[0032] Furthermore, the blister pack is equipped with a counterweight.

[0033] Furthermore, the weight of the counterweight gradually decreases along the direction from the liquid receiving tray of the tower plate to the overflow weir.

[0034] The function of the counterweight is to prevent the blister pack from rising and falling frequently. When pressure fluctuates, only a portion of the blister pack rises to eliminate the pressure fluctuation.

[0035] Beneficial effects

[0036] 1. This invention adopts a feeding method in which the gas phase of the high-pressure column of the pressure swing distillation is directly fed into the low-pressure column, thereby improving distillation efficiency and saving energy.

[0037] 2. This invention employs a special bubble cap structure, which quickly and automatically eliminates pressure fluctuations in the gas phase feed from multiple aspects, thus avoiding flooding.

[0038] 3. The bubble cap of the present invention not only eliminates pressure fluctuations but also stabilizes gas-liquid contact, effectively compensating for the possibility of distillation operation imbalance caused by slow manual adjustment, and maintaining stable gas-liquid contact, eliminating dead zones on the tray, and improving distillation efficiency.

[0039] 4. The trays of this invention are provided with guide plates and the bubble caps are provided with counterweights, which makes the distillation operation more stable.

[0040] 5. This invention can not only purify methanol by distillation, but also separate and purify acetone and butanone, thereby improving the utilization rate of crude alcohol. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of the present invention;

[0042] Figure 2 This is a schematic diagram of the connection between the tray and the bubble cap of the present invention;

[0043] Figure 3 This is a front view of the connection between the tray and the bubble cap of the present invention;

[0044] Figure 4 yes Figure 3 Enlarged view of part A;

[0045] Figure 5 This is a schematic diagram of the riser pipe of the present invention;

[0046] Figure 6 This is a schematic diagram of the structure of the blister pack of the present invention (excluding the counterweight).

[0047] The attached diagram is labeled as follows: 1. Low-pressure tower; 2. High-pressure tower; 3. Tower body; 4. First distributor; 5. First booster pump; 6. Second distributor; 7. Pressure reducing valve; 8. Third distributor; 9. Tower plate; 10. Gas riser pipe; 11. Baffle plate; 12. Gas outlet; 13. Vent hole; 14. Bubble cap; 15. Sliding sleeve; 16. Cover; 17. Gear; 18. Limiting ring; 19. Limiting groove; 20. Drain hole; 21. Guide plate; 22. Guide groove; 23. Nut; 24. Flow guide plate; 25. Counterweight; 26. Drain hole; 27. Second booster pump. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0049] like Figure 1 As shown, a distillation column for crude alcohol separation includes at least two pressure swing separation sections connected in series, namely a first pressure swing separation section and a second pressure swing separation section, each of which includes at least a low-pressure column 1 and a high-pressure column 2.

[0050] In the low-pressure tower 1, "low pressure" refers to normal pressure or negative pressure, while in the high-pressure tower 2, "high pressure" refers to positive pressure.

[0051] Each low-pressure tower 1 and high-pressure tower 2 includes a tower body 3, a tower top outlet pipeline, a tower top condenser, a reflux pipeline, a tower bottom outlet pipeline, and a tower bottom reboiler. In each of the pressure-switching separation sections, the tower top gas phase outlet pipeline of the low-pressure tower 1 is connected to a first distributor 4. One outlet of the first distributor 4 is connected to the tower top condenser and used for reflux, and the other outlet is connected to the feed pipeline of the high-pressure tower 2 in the same pressure-switching separation section via a first pressurizing pump 5. The tower top gas phase outlet pipeline of the high-pressure tower 2 is connected to a second distributor 6. One outlet of the second distributor 6 is connected to the tower top condenser of the high-pressure tower 2, and the other outlet is connected to the feed pipeline of the low-pressure tower 1 in the same pressure-switching separation section via a pressure reducing valve 7.

[0052] The bottom liquid phase collection pipeline of the low-pressure tower 1 in the first pressure-switching separation section is connected to the third distributor 8. One outlet of the third distributor 8 is connected to the reboiler of the low-pressure tower 1 in the first pressure-switching separation section, and the other outlet is connected to the feed pipeline of the high-pressure tower 1 in the second pressure-switching separation section via the second pressurizing pump 27. Acetone is collected from the bottom collection pipeline of the high-pressure tower 2 in the first pressure-switching separation section, methanol is collected from the low-pressure tower 1 in the second pressure-switching separation section, and butanone is collected from the high-pressure tower 2 in the second pressure-switching separation section.

[0053] Other connection methods not mentioned in this invention, such as the connection of the bottom reboiler and the top condenser, all adopt conventional connection methods.

[0054] like Figure 1 As shown, Figure 1 The CCP has two transformer separation units, one of which is located in Figure 1 In the upper middle section of the pressure-switching separation unit, the distillation column on the left is a low-pressure column, and the distillation column on the right is a high-pressure column; Figure 1 In the lower middle section of the pressure-switching separation unit, the left distillation column is a high-pressure column and the right distillation column is a low-pressure column.

[0055] like Figure 2 , Figure 3 and Figure 4As shown, the low-pressure tower 1 has a tower plate 9, with a liquid receiving tray and a downcomer at each end of the tower plate 9. A riser pipe 10 is provided on the tower plate 9. The riser pipe 10 is a circular tube. A baffle 11 is provided in the middle of the riser pipe 10, dividing the internal space of the riser pipe 10 into upper and lower parts. At least one air outlet 12 is provided on the side wall of the riser pipe 10 below the baffle 11, and at least one vent hole 13 is provided on the side wall of the riser pipe 10 above the baffle 11. The vent hole 13 is a triangular hole with its tip pointing downwards. A bubble cap 14 is provided outside the riser pipe 10. The bubble cap 14 includes a sliding sleeve 15 and a cover 16. The cover 16 is approximately bell-shaped, i.e., the upper end is spherically closed and the lower end is cylindrical. The cover 16 has an opening and a through hole at the middle of its upper end. The cover 16 is fitted over the riser pipe 10 through the through hole. The inner diameter of the cover 16 is larger than the outer diameter of the riser pipe 10. The cover 16 has a toothed slit 17 arranged on it, which is lower than the air outlet 12 at the upper end of the riser pipe 10. The upper end of the cover 16 is coaxially connected to a sliding sleeve 15. The sliding sleeve 15 slides in contact with the outer wall of the riser pipe 10 and covers the vent hole 13. When the bubble cap 14 slides to the highest position relative to the riser pipe 10, the toothed slit 17 is flush with the air outlet at the upper end of the riser pipe 10. When the bubble cap 14 descends to the lowest position relative to the riser pipe 10, the lower end of the cover 16 contacts the tower plate 9, and the air outlet 12 is connected to the cover 16. The cover 16 and the vent hole 13 are misaligned.

[0056] When the pressure below the tray 9 suddenly increases, the gas velocity in the riser pipe 10 increases, and the gas velocity passing through the toothed slot 17 also increases. The gas-liquid mixing above the tray 9 is enhanced. At the same time, when the gas pressure below the tray 9 suddenly increases, the pressure pushes the bubble cap 14 upward through the airflow in the riser pipe 10, causing the bubble cap 14 to rise. After the bubble cap 14 rises, the vent hole 13 connects with the cover 16, and the airflow in the outlet 12 can be discharged through the vent hole 13 into the upper part of the riser pipe 10. This part of the airflow is directly discharged into the gas phase above the tray 9 through the upper part of the riser pipe 10 and the sliding sleeve 15, without participating in the gas-liquid mixing on the tray 9. This avoids the foam entrainment phenomenon caused by excessive gas-liquid mixing and ensures the stable operation of the equipment.

[0057] Above tray 9 is a zone of intense gas-liquid contact, where the liquid phase is strongly disturbed and agitated by the gas phase. This liquid can easily splash into the upper part of the riser pipe 10, causing liquid accumulation. Consequently, during pressure fluctuations, the gas flow is hindered because of the liquid accumulation in the upper part of the riser pipe 10 after the vent 13 connects to the cover 16. Therefore, improvements are made to the riser pipe 10 and the bubble cap 14. A limiting ring 18 is provided at the upper end of the outer wall of the riser pipe 10, and a limiting groove 19 is provided on the inner wall of the sliding sleeve 15. When the cover 16 moves close to the upper end of the riser pipe 10, the limiting ring 18 limits the bubble cap 14. Figure 4 and Figure 6As shown, the sliding sleeve 15 is provided with a drain hole 20 that connects to the lower end of the limiting groove 19, and the air riser 10 is provided with a drain hole 26 located on the upper side of the partition plate. The lower end of the drain hole 26 is flush with the upper surface of the partition plate 11. The drain hole 20 can drain the accumulated liquid and keep the upper part of the air riser 10 open, which is conducive to the rapid elimination of pressure fluctuations.

[0058] like Figure 2 , Figure 4 and Figure 6 As shown, each of the toothed slots 17 is provided with an inclined guide plate 21 on its outer side. The guide plate 21 is at an angle to the radial direction of the cover 16. When gas and liquid pass through, the cover 16 generates rotational power, and the bubble cap 14 rotates around the riser pipe 10.

[0059] like Figure 4 and Figure 5 As shown, in order to make the connection between the riser pipe 10 and the bubble cap 14 stable and easy to assemble and disassemble, the riser pipe 10 is first snapped into the tower plate 9. The lower end of the outer wall of the riser pipe 10 is provided with a guide groove 22. The tower plate 9 is provided with an installation hole for the riser pipe 10 to pass through. The installation hole is provided with a flange that extends into the guide groove 22. The outer wall of the riser pipe 10 above and below the guide groove 22 is provided with threads. Then the riser pipe 10 is fixed to the tower plate 9 by a nut 23.

[0060] like Figure 2 As shown, the tray 9 is provided with a guide plate 24, which causes the liquid phase on the tray 9 to flow in a continuous "S" shape.

[0061] like Figure 3 and Figure 4 As shown, the blister pack 14 is provided with a counterweight 25, which is ring-shaped and fixedly connected to the outside of the blister pack 14.

[0062] The weight of the counterweight 25 gradually decreases along the direction from the liquid receiving pan of the tower plate 9 to the overflow weir.

[0063] The function of the counterweight 25 is to prevent the bubble cap 14 from rising and falling frequently. When the pressure fluctuates, only a part of the bubble cap 14 needs to rise to eliminate the pressure fluctuation, thus preventing all the bubble caps 14 from rising and falling and maintaining the distillation efficiency.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

Claims

1. A distillation column for crude alcohol separation, characterized in that, It includes at least two series-connected transformer separation sections, each of which includes at least one low-pressure tower (1) and one high-pressure tower (2); The gas phase extraction pipeline at the top of the low-pressure tower (1) in each of the pressure-switching separation sections is connected to the first distributor (4). One outlet of the first distributor (4) is connected to the top condenser of the low-pressure tower (1) and used for reflux, and the other outlet is connected to the feed pipeline of the high-pressure tower (2) in the pressure-switching separation section via the first booster pump (5). The gas phase extraction pipeline at the top of the high-pressure tower (2) is connected to the second distributor (6). One outlet of the second distributor (6) is connected to the top condenser of the high-pressure tower (2), and the other outlet is connected to the feed pipeline of the low-pressure tower (1) in the pressure-switching separation section via the pressure reducing valve (7). The two pressure-switching separation sections are the first pressure-switching separation section and the second pressure-switching separation section. The bottom liquid phase collection pipeline of the low-pressure tower (1) in the first pressure-switching separation section is connected to the third distributor (8). One outlet of the third distributor (8) is connected to the reboiler of the low-pressure tower (1) in the first pressure-switching separation section, and the other outlet is connected to the feed pipeline of the high-pressure tower (1) in the second pressure-switching separation section via the second pressurizing pump (27).

2. The distillation column for crude alcohol separation according to claim 1, characterized in that, The low-pressure tower (1) has a tower plate (9), on which a riser pipe (10) is provided. A bubble cover (14) is provided outside the riser pipe (10). The bubble cover (14) has a toothed slit (17) arranged below the upper outlet (12) of the riser pipe (10). The bubble cover (14) is slidably connected to the riser pipe (10).

3. The distillation column for crude alcohol separation according to claim 2, characterized in that, The riser pipe (10) is provided with a partition (11) in the middle. The riser pipe (10) below the partition (11) is provided with an air outlet (12). The riser pipe (10) above the partition (11) is provided with a vent hole (13). The bubble cover (14) includes a sliding sleeve (15) and a cover (16). The inner diameter of the cover (16) is larger than the outer diameter of the riser pipe (10). The toothed slot (17) is located at the lower part of the cover (16). The upper end of the cover (16) is connected to the sliding sleeve (15). The sliding sleeve (15) slides in contact with the outer wall of the riser pipe (10). The sliding sleeve (15) covers the vent hole (13).

4. The distillation column for crude alcohol separation according to claim 3, characterized in that, The upper end of the outer wall of the riser pipe (10) is provided with a limiting ring (18), and the inner wall of the sliding sleeve (15) is provided with a limiting groove (19). When the cover (16) moves close to the upper end of the riser pipe (10), the limiting ring (18) limits the bubble cover (14). The sliding sleeve (15) is provided with a drain hole (20) that connects to the lower end of the limiting groove (19), and the riser pipe (10) is provided with a drain hole (26) located on the upper side of the partition.

5. The distillation column for crude alcohol separation according to claim 3, characterized in that, The width of the vent (13) gradually increases from bottom to top.

6. The distillation column for crude alcohol separation according to claim 2, characterized in that, Each of the toothed slots (17) is provided with an inclined guide plate (21) on the outside, and the guide plate (21) is at an angle to the radial direction of the cover (16).

7. The distillation column for crude alcohol separation according to claim 2, characterized in that, The riser pipe (10) is snapped into the tower plate (9). The lower end of the outer wall of the riser pipe (10) is provided with a guide groove (22). The tower plate (9) is provided with an installation hole for the riser pipe (10) to pass through. The installation hole is provided with a flange that extends into the guide groove (22). The outer wall of the riser pipe (10) above and below the guide groove (22) is provided with threads. The riser pipe (10) is fixed to the tower plate (9) by a nut (23).

8. The distillation column for crude alcohol separation according to claim 2, characterized in that, The tray (9) is provided with a guide plate (24), which makes the liquid phase on the tray (9) flow continuously in an "S" shape.

9. The distillation column for crude alcohol separation according to claim 2, characterized in that, The blister pack (14) is provided with a counterweight (25).

10. The distillation column for crude alcohol separation according to claim 9, characterized in that, The weight of the counterweight (25) gradually decreases along the direction from the liquid receiving pan of the tray (9) to the overflow weir.

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