Buffer device for acrylic acid heavy component

Abstract

The utility model belongs to the technical field of chemical production equipment, and particularly relates to a buffer device for heavy components of acrylic acid, which comprises a first buffer tank, a second buffer tank, a vacuum pump, a water-sealed tank, a tail gas removal pipeline and a first feed pipeline, and the top of the first buffer tank is provided with a feed port, a first gas phase outlet and a second gas phase outlet. The first gas phase outlet is connected with a gas inlet of the second buffer tank through a pipeline; a gas outlet of the second buffer tank is connected with the vacuum pump through a pipeline; the vacuum pump is connected with the tail gas removal pipeline through a pipeline; the second gas phase outlet is connected with the water-sealed tank through a pipeline; the buffer device can avoid gas leakage caused by overpressure of the buffer tank and avoid overtemperature of a catalyst bed layer caused by a large amount of gas entering a tail gas treatment system.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical production equipment, and particularly relates to a buffer device for acrylic heavy components. Background Technique

[0002] The buffer tank is mainly used to buffer the pressure fluctuations in various systems, making the system work more smoothly. In the acrylic preparation process, the acrylic heavy components need to enter the buffer tank alternately through pipeline A and pipeline B, and the gas phase in the tank is extracted for tail gas treatment.

[0003] Due to the actual production requirements, the process flow needs to be switched regularly for steam purging. For example, after switching the process flow of pipeline A to pipeline B to transport acrylic heavy components, in order to avoid the polymerization of acrylic acid in the pipeline, it is necessary to promptly perform steam purging on the heavy components in pipeline A, and purge the heavy components in the pipeline into the buffer tank until it is clean.

[0004] During this steam purging operation process, the following problems exist: Since the viscosity of the heavy components is relatively large, the length of the conveying pipeline is relatively long, and the frictional resistance in the pipeline is relatively large, it is not easy to control the opening degree of the steam purging valve. Once the heavy component pipeline is blown through, a large amount of gas-phase acrylic acid, steam, etc. will be instantly generated in the buffer tank. Due to the certain load capacity of the tail gas treatment, the pressure in the buffer tank will rise from 95KPaA to 102KPaA in a short time, and acrylic acid gas will be discharged from the water seal tank vent to the atmosphere, resulting in an unpleasant smell in the surrounding environment and polluting the environment. At the same time, it will also increase the safety risk of the catalyst bed layer overheating in the tail gas treatment system. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the problem that after steam purging described in the above background technique, waste gas will be instantly generated in the buffer tank and discharged to the atmosphere, and the tail gas treatment system is overloaded. Here, a new buffer device for acrylic heavy components is proposed. This buffer device can avoid the discharge of acrylic acid gas to the atmosphere during purging and avoid the overheating of the catalyst bed layer in the tail gas treatment system.

[0006] The technical solution adopted to achieve the above purpose is a buffer device for acrylic heavy components. The buffer device includes a first buffer tank, a second buffer tank, a vacuum pump, a water seal tank, a tail gas pipeline, and a first feed pipeline. The top of the first buffer tank is provided with a feed port, a first gas phase outlet, and a second gas phase outlet. The first feed pipeline is connected to the feed port. The first gas phase outlet is connected to the inlet of the second buffer tank through a pipeline. The outlet of the second buffer tank is connected to the vacuum pump through a pipeline. The vacuum pump is connected to the tail gas pipeline through a pipeline. The second gas phase outlet is connected to the water seal tank through a pipeline. The water seal tank is connected to the tail gas pipeline through a pipeline.

[0007] In the above technical solution, steam purging is carried out to enable the acrylic heavy components to enter the first buffer tank. The pressure in the first buffer tank gradually rises. When it rises to a certain pressure value, the gas-phase components in the tank enter the second buffer tank, reducing the instantaneous pressure increase in the first buffer tank caused by the pipeline being blown through, and a vacuum pump is used to maintain the pressure stability.

[0008] Further, the buffer device further includes a second feed pipeline, and the second feed pipeline is communicated with the first feed pipeline.

[0009] Further, the buffer device further includes a first steam purging pipeline and a second steam purging pipeline. The first steam purging pipeline is communicated with the first feed pipeline, and the second steam purging pipeline is communicated with the second feed pipeline.

[0010] In the above technical solution, the acrylic heavy components enter the first buffer tank through the steam purging of the first steam purging pipeline and the second steam purging pipeline.

[0011] Further, a regulating valve is provided on the pipeline connecting the first gas-phase outlet and the second buffer tank.

[0012] Further, a first pressure detection device is further provided on the top of the first buffer tank, and the pressure detection device is electrically connected to the regulating valve.

[0013] In the above technical solution, the first pressure detection device is used to monitor the pressure in the first buffer tank in real time. When the pressure exceeds a certain limit value, the regulating valve is automatically opened to introduce the gas-phase in the first buffer tank into the second buffer tank, preventing excessive pressure, and the acrylic gas is discharged into the atmosphere through the water seal tank.

[0014] Further, the second buffer tank is a negative-pressure buffer tank.

[0015] Further, the vacuum pump is a water-ring vacuum pump.

[0016] Further, a second pressure detection device is provided on the second buffer tank.

[0017] Further, the buffer device further includes a DCS control system, and the DCS control system is electrically connected to the vacuum pump and the second pressure detection device.

[0018] In the above technical solution, the start and stop of the vacuum pump are controlled by the DCS control system. When the second pressure detection device rises to the limit value, the vacuum pump is started to slowly pump the gas in the second buffer tank into the tail gas pipeline. When the second pressure detection device detects a value below the limit, the vacuum pump can be manually started through the DCS control system.

[0019] The advantages of the present utility model are as follows:

[0020] 1. The utility model connects the first buffer tank and the second buffer tank in series. The second buffer tank is a negative pressure buffer tank, which can offset the instantaneous pressure increase caused by steam purging and buffer the large amount of gas phase generated.

[0021] 2. The utility model can avoid the gas phase emission problem caused by overpressure of the buffer tank, prevent the gas phase from entering the atmosphere and affect the health of workers.

[0022] 3. The utility model further avoids the problem that the first buffer tank is overpressurized due to the excessive opening of the steam purging valve by the worker's misoperation. Moreover, the upper limit of the opening of the steam purging valve can be increased, the pipeline purging time can be shortened, and the work efficiency can be improved.

[0023] 4. The utility model avoids a large amount of organic matter from instantly entering the tail gas treatment system, resulting in the risk of overheating of the catalyst bed layer. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of the present utility model.

[0026] Illustration: 1. First buffer tank, 2. Second buffer tank, 3. Vacuum pump, 4. Water seal tank, 5. Tail gas pipeline, 6. First feed pipeline, 7. Second feed pipeline, 8. First steam purging pipeline, 9. Second steam purging pipeline, 10. Control valve, 101. Feed inlet, 102. First gas phase outlet, 103. Second gas phase outlet, 104. First pressure detection device, 201. Second pressure detection device. Detailed Embodiments

[0027] In order to enable those skilled in the art to better understand the solutions of the present utility model, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present utility model.

[0028] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0029] As Figure 1 shown, a buffer device for acrylic heavy components, the buffer device is composed of a first buffer tank 1, a second buffer tank 2, a vacuum pump 3, a water seal tank 4, a tail gas removal pipeline 5, a first feed pipeline 6, a second feed pipeline 7, a first steam purging pipeline 8, a second steam purging pipeline 9 and a DCS control system. Among them, the top of the first buffer tank is provided with a feed port 101, a first gas phase outlet 102, a second gas phase outlet 103 and a first pressure detection device 104. The first feed pipeline is communicated with the feed port. The first gas phase outlet is communicated with the intake port of the second buffer tank through a pipeline. The outlet of the second buffer tank is communicated with the vacuum pump through a pipeline. The vacuum pump is communicated with the tail gas removal pipeline through a pipeline. The second gas phase outlet is communicated with the water seal tank through a pipeline. The water seal tank is communicated with the tail gas removal pipeline through a pipeline. The second feed pipeline is communicated with the first feed pipeline. The first steam purging pipeline is communicated with the first feed pipeline. The second steam purging pipeline is communicated with the second feed pipeline.

[0030] In this embodiment, a regulating valve 10 is provided on the pipeline connecting the first gas phase outlet and the second buffer tank, and the regulating valve is electrically connected to the first pressure detection device.

[0031] A second pressure detection device 201 is provided on the second buffer tank, and the DCS control system is electrically connected to the vacuum pump and the second pressure detection device.

[0032] In this embodiment, the second buffer tank is a negative pressure buffer tank for buffering and offsetting a large amount of gas phase generated in the first buffer tank.

[0033] In this embodiment, the vacuum pump is a water ring vacuum pump for extracting the gas phase in the second buffer tank into the tail gas removal pipeline to maintain pressure stability.

[0034] The working process of the utility model: Steam is introduced into the first feed pipeline or the second feed pipeline communicated with each other through the first steam purging pipeline or the second steam purging pipeline, and the residual acrylic heavy components in the pipeline are purged into the first buffer tank. The pressure in the first buffer tank continues to rise. When the first pressure detection device detects that the pressure rises to 98 KPaA, the regulating valve is opened, and the gaseous acrylic acid and steam in the first buffer tank are introduced into the second buffer tank. At this time, the pressure in the first buffer tank decreases, and the pressure in the second buffer tank rises. When the first pressure detection device detects that the pressure drops to 95 KPaA, the regulating valve is closed.

[0035] If the second pressure detection device detects that the pressure rises above 93 KpaA, the DCS control system controls the vacuum pump to start, and slowly pumps the gas phase in the second buffer tank into the tail gas pipeline to avoid overheating of the tail gas treatment system. The pressure in the second buffer tank decreases. When the second pressure detection device detects that the pressure drops to 3 KpaA, the DCS control system controls the vacuum pump to close.

[0036] If the second pressure detection device detects that the pressure is between 3 - 93 KpaA, the DCS control system can be manually controlled to start the vacuum pump. When the pressure in the second buffer tank drops to 3 KpaA, the DCS control system automatically controls the vacuum pump to close.

[0037] Finally, it should be noted that this embodiment is only used to illustrate the utility model and does not limit the scope of the utility model. In addition, it should be understood that after reading the content taught by the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A buffer device for acrylic acid heavy components, characterized in that: The buffer device comprises a first buffer tank (1), a second buffer tank (2), a vacuum pump (3), a water seal tank (4), a tail gas removal pipeline (5) and a first feed pipeline (6); a feed port (101), a first gas phase outlet (102) and a second gas phase outlet (103) are provided at the top of the first buffer tank; the first feed pipeline is connected to the feed port; the first gas phase outlet is connected to the gas inlet of the second buffer tank via a pipeline; the gas outlet of the second buffer tank is connected to the vacuum pump via a pipeline; the vacuum pump is connected to the tail gas removal pipeline via a pipeline; the second gas phase outlet is connected to the water seal tank via a pipeline; the water seal tank is connected to the tail gas removal pipeline via a pipeline.

2. The buffer device according to claim 1, characterized in that: The buffer device further comprises a second feed line (7), wherein the second feed line is connected to the first feed line.

3. The buffer device according to claim 2, characterized in that: The buffer device further comprises a first steam purge pipeline (8) and a second steam purge pipeline (9), wherein the first steam purge pipeline is connected to the first feed pipeline, and the second steam purge pipeline is connected to the second feed pipeline.

4. The buffer device according to claim 1, characterized in that: A regulating valve (10) is provided on the pipeline connecting the first gas phase outlet and the second buffer tank.

5. The buffer device according to claim 4, characterized in that: A first pressure detection device (104) is also provided on the top of the first buffer tank, and the first pressure detection device is electrically connected to the regulating valve.

6. The buffer device according to claim 1, characterized in that: The second buffer tank is a negative pressure buffer tank.

7. The buffer device according to claim 1, characterized in that: The vacuum pump is a water ring vacuum pump.

8. The buffer device according to claim 1, characterized in that: The second buffer tank is provided with a second pressure detection device (201).

9. The buffer device according to claim 8, characterized in that: The buffer device preferably includes a DCS control system, and the DCS control system is electrically connected to the vacuum pump and the second pressure detection device.

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