CN219091134U

CN219091134U - Reflux tank liquid discharge device in crude benzene refining process

Info

Publication number: CN219091134U
Application number: CN202223514915.3U
Authority: CN
Inventors: 任闪闪; 陈云生; 路翠翠; 冯小婉
Original assignee: Puyang Eurasian Chemical Technology Co ltd
Current assignee: Puyang Eurasian Chemical Technology Co ltd
Priority date: 2022-12-28
Filing date: 2022-12-28
Publication date: 2023-05-30
Anticipated expiration: 2032-12-28

Abstract

The utility model relates to the technical field of crude benzene refining, in particular to a liquid draining device of a reflux tank in a crude benzene refining process. Including the benzene tower, the exit tube at benzene tower top is through first branch pipe and second branch pipe and reflux drum intercommunication, installs third valve and booster pump on first branch pipe and the second branch pipe respectively, and the reflux drum lower extreme is fixed with the lower tank rather than the intercommunication, and the reflux drum passes through communicating pipe intercommunication with the bottom of the rectifying column, installs the second valve on communicating pipe, and lower tank passes through the calandria intercommunication with the recovery tank, installs first valve on the calandria, recovery tank and waste water tank intercommunication. Before the separated water in the lower tank is discharged, the third valve is closed, the booster pump is started, and mixed steam at the top of the benzene tower is forcedly conveyed into the reflux tank through the booster pump, so that the pressure in the reflux tank is higher than the pressure of the recovery tank, the separated water can be ensured to be discharged to the recovery tank, and the backflow of the separated water can be avoided by arranging the check valve on the drain pipe.

Description

Reflux tank liquid discharge device in crude benzene refining process

Technical Field

The utility model relates to the technical field of crude benzene refining, in particular to a liquid draining device of a reflux tank in a crude benzene refining process.

Background

In the crude benzene hydrofining process, mixed steam discharged from the top of a benzene tower is required to be discharged into a reflux tank for storage and condensation, a mixture of benzene liquid and separated water is formed after the mixed steam is condensed, and according to the polarity and density layering characteristics of the separated water and the benzene liquid, the upper layer in the reflux tank is the benzene liquid, and the lower layer is the separated water. Benzene liquid is extracted and then injected into a distillation tower for refining, and separated water is sent into a wastewater tank for centralized treatment.

Patent document with application number of CN202122988177.5, entitled reflux tank liquid discharge device in crude benzene refining process, discloses a device capable of automatically discharging benzene liquid and water. In the device, a reflux tank liquid level meter B and a water drum liquid level meter C are connected into a DCS remote control system, so that the liquid level of benzene liquid in the reflux tank body 1 and separated water in the water drum 2 can be automatically monitored in real time, and when the water level of the separated water reaches a set value, the DCS remote control system controls a front gate valve 3, a regulating valve 4 and a rear gate valve 5 to be opened, so that the separated water in the water drum 2 is discharged. The benzene liquid in the reflux tank body is sent to a rectifying tower for refining.

In the device, if the pressure in the reflux tank body 1 is too low, the pressure of the recovery tank body 1 is higher than the pressure in the hydrocarbon recovery tank 7 by closing the pressure reducing valve 10 and adjusting the pressure increasing valve 9 to supplement nitrogen into the reflux tank body 1, so that the reflux phenomenon of the system is avoided. The pressure in the reflux tank body is improved by injecting nitrogen into the reflux tank body, and a nitrogen supply system is required to be arranged, so that the cost of refining crude benzene is increased.

Disclosure of Invention

The utility model aims to solve the technical problems that the crude benzene refining cost can be reduced, and when separating water is discharged, the pressure in a reflux tank is further increased by increasing the amount of steam entering the top of a benzene tower in the reflux tank, so that the liquid discharge device of the reflux tank in the crude benzene refining process for separating water reflux is avoided.

In order to achieve the above purpose, the technical scheme provided by the utility model is as follows:

the utility model provides a reflux drum drain in crude benzene refining process, includes the benzene tower, and the exit tube at benzene tower top is through first branch pipe and second branch pipe and reflux drum intercommunication, installs third valve and booster pump on first branch pipe and the second branch pipe respectively, and the reflux drum lower extreme is fixed with the lower jar rather than the intercommunication, and the bottom of reflux drum and rectifying column is through communicating pipe intercommunication, installs the second valve on communicating pipe, and the lower jar passes through calandria intercommunication with the recovery jar, installs first valve on the calandria, and recovery jar and waste water jar intercommunication.

Specifically, an upper liquid level meter and a lower liquid level meter are respectively arranged on the reflux tank and the lower tank. The upper liquid level meter is used for detecting the liquid level of benzene liquid in the reflux tank. The lower level gauge is used for detecting the level of the separated water in the lower tank.

And the reflux tank and the recovery tank are respectively provided with a first pressure sensor and a second pressure sensor. The first pressure sensor and the second pressure sensor can detect the pressure of the reflux drum and the recovery drum in real time.

And check valves are arranged on the calandria. By providing the check valve, when the benzene liquid in the reflux drum is discharged, the reflux of the separated water due to the pressure decrease in the reflux drum can be prevented.

Compared with the prior art, the utility model has the beneficial effects that:

1. before the separated water in the lower tank is discharged, the third valve is closed, the booster pump is started, and mixed steam at the top of the benzene tower is forcedly conveyed into the reflux tank through the booster pump, so that the pressure in the reflux tank is higher than the pressure of the recovery tank, the separated water can be ensured to be discharged to the recovery tank, and the backflow of the separated water can be avoided by arranging the check valve on the drain pipe.

2. After the separated water is discharged, a second valve is started to discharge the benzene liquid in the reflux tank to the distillation tower, so that the mixed steam at the top of the benzene tower is prevented from normally entering the reflux tank due to the fact that the pressure in the reflux tank is high.

3. The device can automatically realize the discharge of separation water and benzene liquid, can reduce the labor intensity of workers, does not need to fill nitrogen into the reflux tank so as to compensate the pressure of the reflux tank, does not need to set a nitrogen supplementing system, and can reduce the equipment investment cost.

Drawings

Fig. 1 is a schematic structural diagram of the device.

The names of the parts in the drawings are as follows:

1. benzene tower

2. Pipe outlet

3. Booster pump

4. Reflux tank

5. Upper liquid level meter

6. Lower tank

7. Lower liquid level meter

8. Calandria tube

9. First valve

10. Recovery tank

11. Waste water tank

12. Communicating pipe

13. Second valve

14. First pressure sensor

15. Second pressure sensor

16. First branch pipe

17. Second branch pipe

18. Third valve

19. A check valve.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments.

Referring to fig. 1, a liquid discharge device of a reflux tank in a crude benzene refining process comprises a benzene tower 1, wherein a pipe 2 at the top of the benzene tower 1 is communicated with the reflux tank 4 through a first branch pipe 16 and a second branch pipe 17, and a third valve 18 and a booster pump 3 are respectively arranged on the first branch pipe 16 and the second branch pipe 17. Before the separated water in the lower tank 6 is discharged, the third valve 18 is closed, the booster pump 3 is started, and the mixed steam at the top of the benzene tower 1 is forcedly conveyed into the reflux tank 4 through the booster pump 3, so that the pressure in the reflux tank 4 is higher than the pressure in the recovery tank 10, and the separated water can be ensured to be discharged to the recovery tank 10.

The lower end of the reflux tank 4 is fixedly provided with a lower tank 6 communicated with the reflux tank, mixed steam at the top of the benzene tower 1 is condensed to form mixed liquid of benzene liquid and separated water, the mixed liquid is stored in the reflux tank 4, and under the action of the polarity and density layering characteristics of the separated water and the benzene liquid, the upper layer in the reflux tank 4 is the benzene liquid, and the lower layer is the separated water. The separated water enters the lower tank 6 for storage. The reflux tank 4 and the lower tank 6 are respectively provided with an upper liquid level meter 5 and a lower liquid level meter 7. The upper liquid level meter 5 is used for detecting the liquid level of the benzene liquid in the reflux tank 4. The lower level gauge 7 is used to detect the level of separated water in the lower tank 6.

The bottom of reflux drum 4 and rectifying column passes through communicating pipe 12 intercommunication, installs second valve 13 on the communicating pipe 12, and lower jar 6 passes through calandria 8 intercommunication with recovery tank 10, installs first valve 9 on the calandria 8, install check valve 19 on the calandria 8. By providing the check valve 19, the backflow of the separated water can be avoided when the separated water is discharged. The check valve 19 can prevent the separated water from flowing back due to a decrease in pressure in the reflux drum 4 when the benzene liquid in the reflux drum 4 is discharged. The recovery tank 10 communicates with a wastewater tank 11.

The reflux drum 4 and the recovery drum 10 are respectively provided with a first pressure sensor 14 and a second pressure sensor 15. The first pressure sensor 14 and the second pressure sensor 15 are capable of detecting the pressures of the reflux drum 4 and the recovery drum 10 in real time.

The upper liquid level meter 5 and the lower liquid level meter 7 are connected into a DCS remote control system, the liquid level of benzene liquid in the reflux tank 4 and the water level of separated water in the lower tank 6 can be monitored in real time, and the first valve 9, the second valve 13, the third valve 18, the first pressure sensor 14 and the second pressure sensor 15 are connected into the DCS remote control system. The DCS remote control system detects the liquid level of benzene liquid in the reflux tank 4 in real time through the upper liquid level meter 5, detects the water level of separated water in the lower tank 6 in real time through the lower liquid level meter 7, and detects the pressure in the reflux tank 4 and the recovery tank 10 in real time through the first pressure sensor 14 and the second pressure sensor 15.

After the water level of the separated water in the lower tank 6 reaches a set height, the DCS remote control system detects the pressure in the reflux drum 4 and the recovery drum 10 through the first pressure sensor 14 and the second pressure sensor 15, then the third valve 18 is automatically closed, and then the booster pump 3 is started, the pressure in the reflux drum 4 is increased by forcibly adding the vapor from the top of the benzene column 1 into the reflux drum 4, and after the pressure in the reflux drum 4 exceeds the pressure in the recovery drum 10, the first valve 9 is opened, and the separated water in the lower tank 6 enters the recovery drum 10 under the action of the pressure in the reflux drum 4. When the water level of the separated water in the lower tank 6 reaches the set lowest level, the second valve 13 is opened, so that the benzene liquid in the reflux tank 4 is discharged, the residual pressure in the reflux tank 4 can be balanced after the benzene liquid is discharged, and the phenomenon that the mixed steam at the top of the benzene tower 1 cannot smoothly enter the reflux tank 4 after being condensed due to the fact that the pressure in the reflux tank 4 is too high is prevented. After the separated water is discharged, the third valve 18 is opened, so that the mixed steam continues to flow into the reflux drum 4.

When the benzene liquid level in the reflux tank 4 reaches the set height, the second valve 13 is opened, the benzene liquid in the reflux tank 4 is injected into the rectifying tower through the communicating pipe 12, and when the benzene liquid is discharged from the reflux tank 4, the mixed steam at the top of the benzene tower 1 is accelerated to enter the reflux tank 4, so that the pressure in the reflux tank 4 is compensated, and the separated water is prevented from flowing back into the reflux tank 4. When the pressure in the return tank 4 is not compensated timely and effectively, the return of the separated water can be avoided due to the non-return valve 19 arranged on the drain pipe 8.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. The utility model provides a reflux drum drain in crude benzol refining process, including benzene tower (1), a serial communication port, exit tube (2) at benzene tower (1) top of the tower are through first branch pipe (16) and second branch pipe (17) and reflux drum (4) intercommunication, install third valve (18) and booster pump (3) respectively on first branch pipe (16) and second branch pipe (17), reflux drum (4) lower extreme is fixed with lower tank (6) rather than the intercommunication, reflux drum (4) are through communicating pipe (12) intercommunication with the tower bottom of rectifying column, install second valve (13) on communicating pipe (12), lower tank (6) are through calandria (8) intercommunication with recovery tank (10), install first valve (9) on calandria (8), recovery tank (10) and waste water tank (11) intercommunication.

2. The liquid draining device of the reflux tank in the crude benzene refining process according to claim 1, wherein an upper liquid level meter (5) and a lower liquid level meter (7) are respectively arranged on the reflux tank (4) and the lower tank (6).

3. The reflux drum drainage device in the crude benzene refining process according to claim 1, wherein the reflux drum (4) and the recovery drum (10) are respectively provided with a first pressure sensor (14) and a second pressure sensor (15).

4. Reflux drum drainage device in crude benzene refining process according to claim 1, characterized in that the gauntlet (8) is fitted with a check valve (19).