Top pressure stabilizing device for rectifying tower

Abstract

The invention discloses a top pressure stabilizing device for a rectifying tower. The top pressure stabilizing device comprises the 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 communicates with the top of the rectifying tower through a first pipeline; the other end of the condenser is communicated with the return tank through a second pipeline; the reflux tank is communicated 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 communicated with the first pipeline through an air inlet pipeline; the other end of the buffer tank is communicated with the first pipeline through an air outlet pipeline; the first control valve is positioned between the air inlet pipeline and the air outlet pipeline; the second control valve is arranged on the air inlet pipeline; pressure sensors are arranged at the tops of the rectifying towers. The device is simple in structure and convenient to operate, the pressure at the tower top can be kept stable, and the situation that the condensation effect is affected due to the fact that the flow of a gas phase entering the condenser suddenly becomes large can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of distillation towers, and more particularly to a top pressure stabilizing device for distillation towers. Background Art

[0002] Distillation is the process of separating a binary or multi-component mixed material by evaporation using the different boiling points of different materials in the raw materials. A distillation tower is a tower-type gas-liquid contact device for distillation. It uses the different volatilities of the components in the mixture, that is, the different vapor pressures of the components at the same temperature, to transfer the light components (low-boiling substances) in the liquid phase to the gas phase, and the heavy components (high-boiling substances) in the gas phase to the liquid phase, thereby achieving the purpose of separation. The distillation tower is also a widely used mass transfer and heat transfer device in petrochemical production. The general distillation device consists of a distillation tower body, a condenser, a reflux tank, and a reboiler. The feed enters the tower from a certain section of the tower plate in the distillation tower. This tower plate is called the feed plate. The feed plate divides the distillation tower into two sections, the upper section above the feed plate is called the distillation section, and the lower section below the feed plate is called the stripping section. At present, distillation is the most widely used mass transfer separation process. Pressure and temperature are two important operating parameters in the distillation process. Especially when distilling and purifying materials with close melting and boiling points, in order to maintain a stable reflux state and obtain continuous high-quality output, the pressure of the distillation tower needs to be stably maintained in a more precise range. At this time, pressure control is particularly important. When using existing distillation towers, it is generally difficult to control the pressure at the top of the tower. When the pressure at the top of the tower fluctuates violently, it will affect the distillation process.

[0003] Therefore, how to provide a top pressure stabilizing device for a distillation tower that can keep the top pressure stable is one of the technical problems that urgently need to be solved in the art. Summary of the invention

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

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A top pressure stabilizing device for a distillation tower comprises: a distillation 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 to the top of the distillation tower through a first pipeline; the other end of the condenser is connected to the reflux tank through a second pipeline; the reflux tank is connected to the top of the distillation tower through a third pipeline; the third control valve and the reflux pump are both arranged on the third pipeline; the first control valve is arranged on the first pipeline; one end of the buffer tank is connected to the first pipeline through an air inlet pipeline; the other end of the buffer tank is connected to 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; a pressure sensor is arranged on the top of the distillation tower.

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

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

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

[0010] Preferably, a flow meter is provided 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 tower through a fourth pipeline; and a fifth control valve is provided on the gas phase pipeline.

[0012] Preferably, an air pump is provided 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 coordination of components such as a buffer tank, a reflux tank, a reflux pump, a first control valve, a second control valve 7, and a third control valve, it can not only maintain the stability of the tower top pressure, but also avoid the sudden increase in the gas phase flow entering the condenser to affect the condensation effect. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0016] In the figure: 1. distillation tower; 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. air pump. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example

[0019] Reference Figure 1-2As shown, the present invention discloses a top pressure stabilizing device for a distillation tower, comprising: a distillation tower 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 tower 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 tower 1 through a third pipeline 11; the third control valve 8 and the reflux pump 5 are both arranged on the third pipeline 11; the first control valve 6 is arranged on the first pipeline 9; one end of the buffer tank 3 is connected to the first pipeline 9 through an air inlet pipeline 12; the other end of the buffer tank 3 is connected to the first pipeline 9 through an air outlet pipeline 13. 9 is connected; 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 arranged on the air inlet pipeline 12; a pressure sensor 14 is arranged on the top of the distillation tower 1 for detecting the top pressure in the distillation tower 1; under normal working conditions, the condenser 2 and the reflux pump 5 are in working condition, the first control valve 6 and the third control valve 8 are in open condition, and the second control valve 7 is in closed condition, the gas phase generated at the top of the distillation tower 1 enters the condenser 2 through the first pipeline 9, and the liquid phase generated after the gas phase is cooled enters the reflux tank 4 through the second pipeline 10, and the liquid phase in the reflux tank 4 is refluxed to the inside of the distillation tower 1 through the reflux pump 5; when the pressure sensor 14 detects that the top of the distillation tower 1 When the pressure rises, the first control valve 6 is closed, and the second control valve 7 is opened and the opening of the second control valve 7 is controlled to be greater than that of the first control valve 6, so that the gas phase generated at the top of the distillation tower 1 enters the buffer tank 3 through the air inlet pipeline 12, and the gas phase in the buffer tank 3 flows into the condenser 2 through the air outlet pipeline 13 and the first pipeline 9 in turn. In this process, the gas phase flow rate flowing out of the distillation tower 1 increases, so that the pressure at the top of the distillation tower 1 can be reduced, thereby keeping the pressure at the top of the tower stable. At the same time, after the gas phase at the top of the distillation tower 1 is buffered by the buffer tank 3, its flow rate entering the condenser 2 will not suddenly increase, thereby ensuring the condensation effect of the gas phase. When the pressure sensor 14 detects that the pressure at the top of the tower has returned to normal and is maintained 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 tower 1 to a normal distillation state; when the pressure sensor 14 detects that the tower top pressure is reduced, the third control valve 8 is controlled to open wider, so that the reflux flow entering the distillation tower 1 is increased, and the gas phase generated at the tower top is increased, thereby increasing the tower top pressure of the distillation tower 1, until the pressure sensor 14 detects that the tower top pressure returns to normal and is maintained for a period of time, the third control valve 8 is controlled to open again to restore the normal state, thereby restoring the distillation tower 1 to a normal distillation state. The whole device has a simple structure and is easy to operate. It can not only keep the tower top pressure stable, but also avoid the gas phase flow entering the condenser from suddenly increasing and affecting the condensation effect.

[0020] The above technical solution connects a buffer tank in parallel on the first pipeline between the distillation tower and the condenser. When the pressure at the top of the distillation tower suddenly increases, the first control valve is closed, and the second control valve is opened at the same time and the opening of the second control valve is controlled to be greater than the first control valve, so that the gas phase flow rate flowing out of the distillation tower can be increased, so that the pressure at the top of the distillation tower can be quickly reduced. At the same time, after the gas phase of the distillation tower is buffered by the buffer tank, the gas phase flow rate entering the condenser can be prevented from suddenly increasing and affecting the condensation effect, thereby ensuring the stable operation of the distillation tower. At the same time, by setting a third control valve, when the pressure sensor detects that the pressure at the top of the tower suddenly decreases, the opening of the third control valve is controlled to be larger, so that the reflux volume entering the distillation tower is increased, and the gas phase generated at the top of the tower increases, thereby increasing the pressure at the top of the distillation tower, until the pressure sensor detects that the pressure at the top of the tower returns to normal and remains for a period of time, the opening of the third control valve is controlled to return to a normal state, so that the distillation tower returns to a normal distillation state, thereby keeping the pressure at the top of the distillation tower stable, avoiding drastic fluctuations (increase or decrease) in the pressure at the top of the distillation tower and affecting the operation of the distillation tower.

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

[0022] In this embodiment, the driving mechanism is a hydraulic cylinder 18 ; the hydraulic cylinder 18 is disposed at one 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; when in use, part 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 provided on the first pipeline 9 between the gas outlet pipeline 13 and the condenser 2 for monitoring the gas phase flow rate entering the condenser 2 .

[0025] In this embodiment, a gas phase pipeline 22 is provided at the top of the reflux tank 4; the gas phase pipeline 22 is connected to the top of the distillation tower 1 through the fourth pipeline 23; a fifth control valve 24 is provided on the gas phase pipeline 22; when the pressure at the top of the distillation tower 1 decreases, the fifth control valve 24 can be opened to allow the gas phase inside the reflux tank 4 to enter the distillation tower 1 through the gas phase pipeline 22 and the fourth pipeline 23 in turn, so as to increase the internal pressure of the distillation tower 1.

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

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

[0028] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A top pressure stabilizing device for a distillation tower, characterized in that: include: A distillation tower (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 tower (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 tower (1) through a third pipeline (11); the third control valve (8) and the reflux pump (5) are both arranged at the top of the distillation tower (1). The first control valve (6) is arranged on the third pipeline (11); the first control valve (6) is arranged on the first pipeline (9); one end of the buffer tank (3) is connected to the first pipeline (9) through an air inlet pipeline (12); the other end of the buffer tank (3) is connected to the first pipeline (9) through an 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 arranged on the air inlet pipeline (12); and a pressure sensor (14) is arranged on the top of the distillation tower (1).

2. A top pressure stabilizing device for a distillation tower according to claim 1, characterized in that: A movable baffle (15) is slidably arranged inside the buffer tank (3); a driving mechanism for driving the movable baffle (15) to move is arranged on the buffer tank (3); a connecting pipe (16) is arranged on the movable baffle (15); the connecting pipe (16) is connected to the air outlet pipeline (13) via a telescopic pipe (17).

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

4. A top pressure stabilizing device for a distillation tower 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); and a fourth control valve (20) is provided on the liquid phase pipeline (19).

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

6. A top pressure stabilizing device for a distillation tower according to claim 1, characterized in that: A gas phase pipeline (22) is provided at the top of the reflux tank (4); the gas phase pipeline (22) is connected to the top of the distillation tower (1) through a fourth pipeline (23); and a fifth control valve (24) is provided on the gas phase pipeline (22).

7. A top pressure stabilizing device for a distillation tower according to claim 6, characterized in that: An air pump (25) is provided on the fourth pipeline (23).

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