Overhead pressure stabilizing device for distillation column

Abstract

The application discloses a top pressure stabilizing device for a rectifying tower, which comprises a rectifying tower, a condenser, a buffer tank, a reflux tank, a reflux pump, a first control valve, a second control valve and a third control valve; one end of the condenser is connected with the top of the rectifying tower through a first pipeline; the other end of the condenser is connected with the reflux tank through a second pipeline; the reflux tank is connected with the top of the rectifying tower through a third pipeline; the third control valve and the reflux pump are arranged on the third pipeline; the first control valve is arranged on the first pipeline; one end of the buffer tank is connected with the first pipeline through an air inlet pipeline; the other end of the buffer tank is connected with the first pipeline through an air outlet pipeline; the first control valve is located between the air inlet pipeline and the air outlet pipeline; the second control valve is arranged on the air inlet pipeline; and the top of the rectifying tower is provided with a pressure sensor. The application has the advantages of simple structure, convenient operation, stable tower top pressure, and avoidance of the influence of the sudden increase of the gas phase flow entering the condenser on the condensation effect.

Description

Technical Field

[0001] This invention relates to the field of distillation column technology, and more specifically to a top pressure stabilizing device for distillation columns. Background Technology

[0002] Distillation is a process that separates a binary or multi-component mixture of materials by evaporation, utilizing the different boiling points of the raw materials. A distillation column is a tower-type gas-liquid contact device for distillation. It utilizes the different volatility of the components in the mixture, i.e., the different vapor pressures of the components at the same temperature, to transfer the lighter components (low-boiling substances) in the liquid phase to the gas phase, while the heavier components (high-boiling substances) in the gas phase transfer to the liquid phase, thus achieving separation. Distillation columns are also a widely used mass and heat transfer device in petrochemical production. A typical distillation unit consists of a distillation column, a condenser, a reflux tank, and a reboiler. The feed enters the column from a certain section of the column, called the feed plate. The feed plate divides the distillation column into upper and lower sections: the section above the feed plate is called the rectification section, and the section below the feed plate is called the stripping section. Currently, distillation is the most widely used mass transfer separation process. Pressure and temperature are two crucial operating parameters in distillation, especially when purifying materials with similar melting and boiling points. To maintain a stable reflux state and obtain consistently high-quality output, the pressure of the distillation column needs to be kept within a precise range. Therefore, pressure control is extremely important. Existing distillation columns commonly suffer from difficulty in controlling the top pressure, and drastic pressure fluctuations at the top can negatively impact the distillation process.

[0003] Therefore, how to provide a top pressure stabilizing device for distillation columns that can maintain stable top pressure is one of the technical problems that urgently need to be solved in this field. Summary of the Invention

[0004] In view of this, the present invention provides a top pressure stabilizing device for a distillation column, the purpose of which is to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A top pressure stabilizing device for a distillation column includes: a distillation column, a condenser, a buffer tank, a reflux tank, a reflux pump, a first control valve, a second control valve, and a third control valve; one end of the condenser is connected to the top of the distillation column via a first pipeline; the other end of the condenser is connected to the reflux tank via a second pipeline; the reflux tank is connected to the top of the distillation column via a third pipeline; the third control valve and the reflux pump are both located on the third pipeline; the first control valve is located on the first pipeline; one end of the buffer tank is connected to the first pipeline via an inlet pipeline; the other end of the buffer tank is connected to the first pipeline via an outlet pipeline; the first control valve is located between the inlet pipeline and the outlet pipeline; the second control valve is located on the inlet pipeline; a pressure sensor is installed at the top of the distillation column.

[0007] Preferably, a movable baffle is slidably disposed inside the buffer tank; a driving mechanism for moving the movable baffle is disposed on the buffer tank; a connecting pipe is disposed on the movable baffle; and the connecting pipe is connected to the air outlet pipe through a telescopic pipe.

[0008] Preferably, the driving mechanism is a hydraulic cylinder; the hydraulic cylinder is located at the end of the buffer tank away from the air intake pipe; the output end of the hydraulic cylinder is connected to the movable baffle on the side away from the air intake pipe.

[0009] Preferably, a liquid phase pipeline is provided on the third pipeline between the reflux pump and the third control valve; a fourth control valve is provided on the liquid phase pipeline.

[0010] Preferably, a flow meter is installed on the first pipeline between the gas outlet pipeline and the condenser.

[0011] Preferably, a gas phase pipeline is provided at the top of the reflux tank; the gas phase pipeline is connected to the top of the distillation column through a fourth pipeline; and a fifth control valve is provided on the gas phase pipeline.

[0012] Preferably, an air pump is installed on the fourth pipeline.

[0013] Compared with the prior art, the present invention has achieved the following technical effects: The present invention has a simple structure and is easy to operate. Through the cooperation of components such as buffer tank, reflux tank, reflux pump, first control valve, second control valve, and third control valve, it can not only maintain the stability of the pressure at the top of the tower, but also avoid the sudden increase in the gas flow rate entering the condenser, which would affect the condensation effect. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the top pressure stabilizing device for a distillation column according to the present invention;

[0015] Figure 2This is a schematic diagram of the buffer tank.

[0016] In the diagram: 1. Distillation column; 2. Condenser; 3. Buffer tank; 4. Reflux tank; 5. Reflux pump; 6. First control valve; 7. Second control valve; 8. Third control valve; 9. First pipeline; 10. Second pipeline; 11. Third pipeline; 12. Inlet pipeline; 13. Outlet pipeline; 14. Pressure sensor; 15. Movable baffle; 16. Connecting pipe; 17. Telescopic pipe; 18. Hydraulic cylinder; 19. Liquid phase pipeline; 20. Fourth control valve; 21. Flow meter; 22. Gas phase pipeline; 23. Fourth pipeline; 24. Fifth control valve; 25. Gas pump. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] Example

[0019] Reference Figure 1-2As shown, this invention discloses a top pressure stabilizing device for a distillation column, comprising: a distillation column 1, a condenser 2, a buffer tank 3, a reflux tank 4, a reflux pump 5, a first control valve 6, a second control valve 7, and a third control valve 8; one end of the condenser 2 is connected to the top of the distillation column 1 via a first pipeline 9; the other end of the condenser 2 is connected to the reflux tank 4 via a second pipeline 10; the reflux tank 4 is connected to the top of the distillation column 1 via a third pipeline 11; the third control valve 8 and the reflux pump 5 are both mounted on the third pipeline 11; the first control valve 6 is mounted on the first pipeline 9; one end of the buffer tank 3 is connected to the first pipeline 9 via an inlet pipeline 12; the other end of the buffer tank 3 is connected to the first pipeline 9 via an outlet pipeline 13. 9 are connected; the first control valve 6 is located between the inlet pipe 12 and the outlet pipe 13; the second control valve 7 is installed on the inlet pipe 12; a pressure sensor 14 is installed at the top of the distillation column 1 to detect the top pressure inside the distillation column 1; under normal operating conditions, the condenser 2 and the reflux pump 5 are in operation, the first control valve 6 and the third control valve 8 are open, and the second control valve 7 is closed. The gas phase generated at the top of the distillation column 1 enters the condenser 2 through the first pipe 9, and the liquid phase generated after the gas phase is cooled enters the reflux tank 4 through the second pipe 10. The liquid phase in the reflux tank 4 is returned to the inside of the distillation column 1 by the reflux pump 5; when the pressure sensor 14 detects the pressure at the top of the distillation column 1... When the pressure increases, the first control valve 6 is closed, and the second control valve 7 is opened simultaneously, with the opening degree of the second control valve 7 greater than that of the first control valve 6. This allows the gas phase generated at the top of distillation column 1 to enter the buffer tank 3 through the inlet pipe 12. The gas phase in the buffer tank 3 then flows into the condenser 2 sequentially through the outlet pipe 13 and the first pipe 9. During this process, the flow rate of the gas phase exiting distillation column 1 increases, thereby reducing the pressure at the top of distillation column 1 and stabilizing it. Simultaneously, the gas phase at the top of distillation column 1 is buffered by the buffer tank 3, preventing a sudden increase in its flow rate into the condenser 2, thus ensuring effective condensation of the gas phase. When the pressure sensor 14 detects that the pressure at the top of the column has returned to normal and remains stable for a period of time... After a period of time, the first control valve 6 is opened and the second control valve 7 is gradually closed to restore the distillation column 1 to normal distillation state. When the pressure sensor 14 detects a decrease in the pressure at the top of the column, the opening of the third control valve 8 is increased to increase the reflux flow into the distillation column 1 and increase the amount of gas generated at the top of the column, thereby increasing the pressure at the top of the distillation column 1. This continues until the pressure sensor 14 detects that the pressure at the top of the column has returned to normal and remains so for a period of time. Then, the opening of the third control valve 8 is restored to normal, thereby restoring the distillation column 1 to normal distillation state. The entire device has a simple structure and is easy to operate. It can not only maintain a stable pressure at the top of the column, but also avoid a sudden increase in the gas flow rate entering the condenser, which would affect the condensation effect.

[0020] The above technical solution connects a buffer tank in parallel on the first pipeline between the distillation column and the condenser. When the pressure at the top of the distillation column suddenly increases, the first control valve is closed, and the second control valve is opened simultaneously with its opening degree greater than that of the first control valve. This increases the flow rate of the vapor phase out of the distillation column, thereby rapidly reducing the pressure at the top of the distillation column. Simultaneously, the buffer tank buffers the vapor phase, preventing a sudden increase in the flow rate into the condenser that could affect the condensation effect, thus ensuring stable operation of the distillation column. Furthermore, by setting a third control valve, when the pressure sensor detects a sudden decrease in the pressure at the top of the column, the opening degree of the third control valve is increased, increasing the reflux flow rate into the distillation column and increasing the vapor phase generated at the top, thus raising the pressure at the top of the distillation column. This continues until the pressure sensor detects that the pressure at the top of the column has returned to normal and remains so for a period of time. Then, the opening degree of the third control valve is returned to normal, allowing the distillation column to return to normal distillation conditions. This ensures that the pressure at the top of the distillation column remains stable, preventing drastic fluctuations (increases or decreases) that could affect the operation of the distillation column.

[0021] In this embodiment, a movable baffle 15 is slidably disposed inside the buffer tank 3; a driving mechanism for moving the movable baffle 15 is provided on the buffer tank 3; a connecting pipe 16 is provided on the movable baffle 15, which connects the inner cavities on both sides of the movable baffle 15; the connecting pipe 16 is connected to the gas outlet pipe 13 through the telescopic pipe 17; in use, after the gas phase enters the buffer tank 3 through the gas inlet pipe 12, the gas phase inside the buffer tank 3 flows into the condenser 2 after passing through the connecting pipe 16, the telescopic pipe 17, the gas outlet pipe 13 and the first pipe 9 in sequence. During this process, the movable baffle 15 can be moved inside the buffer tank 3 by the driving mechanism, and the position of the movable baffle 15 inside the buffer tank 3 can be adjusted, thereby adjusting the buffering effect of the buffer tank 3 on the gas phase, and thus adjusting the flow rate of the gas phase entering the condenser 2, so that the flow rate entering the condenser is kept within the normal range, ensuring the condensation effect.

[0022] In this embodiment, the driving mechanism is a hydraulic cylinder 18; the hydraulic cylinder 18 is located at the end of the buffer tank 3 away from the air intake pipe 12; the output end of the hydraulic cylinder 18 is connected to the side of the movable baffle 15 away from the air intake pipe 12.

[0023] In this embodiment, a liquid phase pipeline 19 is provided on the third pipeline 11 between the reflux pump 5 and the third control valve 8; a fourth control valve 20 is provided on the liquid phase pipeline 19; in use, a portion of the liquid phase in the reflux tank 4 can be discharged through the liquid phase pipeline 19 and the fourth control valve 20 for subsequent processing and production.

[0024] In this embodiment, a flow meter 21 is installed on the first pipeline 9 between the gas outlet pipeline 13 and the condenser 2 to monitor the gas flow rate entering the condenser 2.

[0025] In this embodiment, a vapor phase pipeline 22 is provided at the top of the reflux tank 4; the vapor phase pipeline 22 is connected to the top of the distillation column 1 through a fourth pipeline 23; a fifth control valve 24 is provided on the vapor phase pipeline 22; when the pressure at the top of the distillation column 1 decreases, the fifth control valve 24 can be opened to allow the vapor phase inside the reflux tank 4 to enter the distillation column 1 sequentially through the vapor phase pipeline 22 and the fourth pipeline 23, thereby increasing the internal pressure of the distillation column 1.

[0026] In this embodiment, an air pump 25 is installed on the fourth pipeline 23.

[0027] In this embodiment, a sealing ring is provided on the outer surface of the movable baffle 15.

[0028] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A top pressure stabilizing device for a distillation column, characterized in that, include: The distillation column (1), condenser (2), buffer tank (3), reflux tank (4), reflux pump (5), first control valve (6), second control valve (7), and third control valve (8); one end of the condenser (2) is connected to the top of the distillation column (1) through a first pipeline (9); the other end of the condenser (2) is connected to the reflux tank (4) through a second pipeline (10); the reflux tank (4) is connected to the top of the distillation column (1) through a third pipeline (11); the third control valve (8) and the reflux pump (5) are both located in the distillation column (1). The first control valve (6) is located on the third pipeline (11); the first control valve (6) is located on the first pipeline (9); one end of the buffer tank (3) is connected to the first pipeline (9) through the air inlet pipeline (12); the other end of the buffer tank (3) is connected to the first pipeline (9) through the air outlet pipeline (13); the first control valve (6) is located between the air inlet pipeline (12) and the air outlet pipeline (13); the second control valve (7) is located on the air inlet pipeline (12); a pressure sensor (14) is provided at the top of the distillation column (1); The buffer tank (3) is slidably provided with a movable baffle (15); the buffer tank (3) is provided with a driving mechanism for moving the movable baffle (15); the movable baffle (15) is provided with a connecting pipe (16); the connecting pipe (16) is connected to the air outlet pipe (13) through a telescopic pipe (17).

2. The top pressure stabilizing device for a distillation column according to claim 1, characterized in that, The driving mechanism is a hydraulic cylinder (18); the hydraulic cylinder (18) is located at the end of the buffer tank (3) away from the air intake pipe (12); the output end of the hydraulic cylinder (18) is connected to the side of the movable baffle (15) away from the air intake pipe (12).

3. The top pressure stabilizing device for a distillation column according to claim 1, characterized in that, A liquid phase pipeline (19) is provided on the third pipeline (11) between the reflux pump (5) and the third control valve (8); a fourth control valve (20) is provided on the liquid phase pipeline (19).

4. The top pressure stabilizing device for a distillation column according to claim 3, characterized in that, A flow meter (21) is installed on the first pipeline (9) between the gas outlet pipeline (13) and the condenser (2).

5. The top pressure stabilizing device for a distillation column according to claim 1, characterized in that, The top of the reflux tank (4) is provided with a gas phase pipeline (22); the gas phase pipeline (22) is connected to the top of the distillation column (1) through a fourth pipeline (23); a fifth control valve (24) is provided on the gas phase pipeline (22).

6. The top pressure stabilizing device for a distillation column according to claim 5, characterized in that, An air pump (25) is installed on the fourth pipeline (23).

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