Blowing system for outlet pipeline of butadiene safety valve

Abstract

The utility model relates to a purging system for an outlet pipeline of a butadiene safety valve. The purging system comprises a butadiene tank, a nitrogen supplementing flow path at the top of the tank, a torch discharge overline unit, a torch discharge pipeline, a safety valve group and a nitrogen purging flow path, a pipeline is led out from the top of the butadiene tank and is connected with a horizontal branch pipeline, and a side branch on one side of the horizontal branch pipeline is bridged to a torch discharge pipeline through a torch discharge overline unit; a safety valve group is arranged on the torch discharge overline unit; a horizontal branch pipeline in the same direction as the torch discharge overline unit is connected with a nitrogen supplementing flow, nitrogen from the outside of the system is introduced, and a nitrogen source is supplemented for a butadiene tank; the nitrogen supplementing process is connected to the safety valve group through the nitrogen purging process; according to the scheme, on the basis of an original pipeline, the nitrogen purging process is added, continuous purging of the safety valve outlet pipeline is achieved, and nitrogen is supplemented when the pressure of the storage tank is insufficient; and the outlet of the safety valve is continuously purged, so that dangers caused by self-polymerization of residual butadiene in the pipeline due to jumping of the safety valve are avoided.

Description

Technical Field

[0001] This utility model relates to a pipeline purging process in a chemical process system, specifically a butadiene safety valve outlet pipeline purging system, belonging to the field of chemical technology. Background Technology

[0002] With the rapid development of my country's chemical industry, butadiene, as an important raw material for synthetic rubber, has attracted increasing attention. However, butadiene is a highly reactive compound with flammable, explosive, and self-polymerizing properties, making its storage and transportation processes quite challenging. Therefore, in recent years, optimizing the storage and transportation processes of butadiene has become a focus of research for domestic butadiene users.

[0003] In the existing process systems of butadiene users, the outlet of the safety valve on the top of the butadiene tank is not equipped with corresponding start-up protection measures. After the safety valve starts, the residual butadiene in the pipeline cannot be purged in time, which leads to polymerization and causes safety accidents. Utility Model Content

[0004] Given that the above-mentioned butadiene process system lacks a safety valve tripping guarantee, the purpose of this utility model is to provide a butadiene safety valve outlet pipeline purging system. By technically modifying the process system structure and adding a purging process for the safety valve pipeline, the original design defects are made up for, and the occurrence of safety accidents is effectively avoided.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: a butadiene safety valve outlet pipeline purging system, comprising: a butadiene tank, a nitrogen replenishment process at the top of the tank, a flare purging unit, a flare purging pipeline, a safety valve assembly, and a nitrogen purging process; the butadiene tank top outlet pipeline is connected to a horizontal branch pipeline, and one side branch of the horizontal branch pipeline is connected to the flare purging pipeline via the flare purging unit, and the nitrogen is delivered to the flare network via the flare purging pipeline; a safety valve assembly is installed on the flare purging unit; a nitrogen replenishment process is connected to the horizontal branch pipeline in the same direction as the flare purging unit, and nitrogen from outside the system is introduced to replenish the nitrogen source for the butadiene tank; the nitrogen replenishment process is connected to the safety valve assembly via the nitrogen purging process;

[0006] Furthermore, the flare discharge line unit includes a line and a control valve. A safety valve assembly is installed before and after the control valve via a bypass pipeline. The safety valve assembly includes a safety valve and its front and rear valves. The rear valve of the safety valve is directed towards the outlet of the safety valve.

[0007] Furthermore, the nitrogen replenishment process includes: a nitrogen pipeline, a pressure regulating valve group, and a check valve; a check valve is installed at the front end of the pressure regulating valve group, and the pressure regulating valve group includes: a pressure regulating valve and its front valve and rear valve, and a bypass backup valve is installed at the front end of the front valve and the rear end of the rear valve through a bypass pipeline.

[0008] Furthermore, the nitrogen purging process includes: a nitrogen purging pipeline, a check valve, and a manual valve; one end of the nitrogen purging pipeline is connected between the pressure regulating valve of the nitrogen pipeline in the nitrogen replenishment process and its downstream valve, and the other end is connected between the safety valve and its downstream valve.

[0009] Furthermore, the check valve on the nitrogen purging line is located close to the nitrogen pipeline. The front end of the check valve is a manual valve, which is used to control the gas flow. The check valve is designed to prevent the flare gas and the gas in the butadiene storage tank from flowing back into the nitrogen pipeline.

[0010] Furthermore, the nitrogen purging line is connected using a Φ12 instrument duct.

[0011] Furthermore, on the other side branch of the horizontal branch pipeline at the top of the butadiene tank, two auxiliary cross lines for the flare discharge network are installed in parallel, and both auxiliary cross lines are connected to the flare discharge pipeline; safety angle valves are installed on the two auxiliary cross lines respectively, and control valves are installed before and after each safety angle valve.

[0012] If the safety valve of the flare discharge line unit in the process system cannot be adjusted, the safety angle valve on the other auxiliary line can be switched to trip. When the system pressure is low, the safety valve of the flare discharge line unit will trip when the pressure is 0.4 MPa, and the safety angle valve on the auxiliary line will trip when the pressure is 0.5 MPa. It should be noted that both auxiliary processes of the process system and the flare discharge line unit process are in operation. The safety angle valve in the auxiliary process will not trip if the pressure is less than 0.5 MPa.

[0013] The purging process of the butadiene safety valve outlet pipeline purging system with the above structure is as follows:

[0014] During normal operation of the butadiene storage tank, the rear valve of the safety valve, the manual valve on the nitrogen purging pipeline, and the rear valve of the pressure regulating valve on the nitrogen pipeline are opened sequentially. External nitrogen enters the nitrogen pipeline and then the nitrogen purging pipeline. After exiting the nitrogen purging pipeline, it enters the rear end of the safety valve, thereby achieving continuous purging of the safety valve outlet by low-pressure nitrogen. In this process system, the rear valve of the safety valve, the manual valve on the nitrogen purging pipeline, and the rear valve of the pressure regulating valve on the nitrogen pipeline are normally open.

[0015] The beneficial effects of this utility model are:

[0016] To address the lack of a continuous purging process at the outlet of the butadiene safety valve in the butadiene process system, a nitrogen purging process is added to the existing pipeline to achieve continuous purging of the safety valve outlet pipeline. This process not only replenishes nitrogen when the storage tank pressure is insufficient, but also ensures continuous purging of the safety valve outlet, preventing the self-polymerization of residual butadiene in the pipeline due to safety valve activation and potential hazards. Furthermore, the use of instrument ducts reduces nitrogen waste. This design saves nitrogen and minimizes costs while ensuring safety. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the butadiene safety valve outlet pipeline purging system of this utility model.

[0018] In the diagram, 1. Butadiene tank, 2. Flare line, 3. Horizontal branch line, 4. Crossover line, 5. Control valve, 6. Safety valve, 7. Nitrogen line, 8. Check valve, 9. Pressure regulating valve, 10. Bypass backup valve, 11. Nitrogen purging line, 12. Check valve, 13. Manual valve, 14. Auxiliary crossover line, 15. Safety angle valve. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0020] like Figure 1 The butadiene safety valve outlet pipeline purging system shown includes: a butadiene tank 1, a nitrogen replenishment process at the top of the tank, a flare flare crossover unit, a flare flare pipeline 2, a safety valve assembly, and a nitrogen purging process; the butadiene tank 1 has a pipeline leading out from the top and connected to a horizontal branch pipeline 3, one side of the horizontal branch pipeline 3 is connected to the flare flare pipeline 2 via the flare flare crossover unit, and the nitrogen is delivered to the flare network through the flare flare pipeline 2; a safety valve assembly is installed on the flare flare crossover unit; the horizontal branch pipeline 3 in the same direction as the flare flare crossover unit is connected to the nitrogen replenishment process, whereby nitrogen from outside the system is introduced to replenish the nitrogen source for the butadiene tank 1; the nitrogen replenishment process is connected to the safety valve assembly via the nitrogen purging process.

[0021] The flare discharge cross-line unit includes a cross-line 4 and a control valve 5. Safety valve groups are installed before and after the control valve 5 through bypass pipelines. The safety valve group includes a safety valve 6 and its front and rear valves. The rear valve of the safety valve 6 is directed to the outlet of the safety valve.

[0022] The nitrogen replenishment process includes: a nitrogen pipeline 7, a pressure regulating valve group and a check valve 8; a check valve 8 is set at the front end of the pressure regulating valve group, and the pressure regulating valve group includes: a pressure regulating valve 9 and its front valve and rear valve, and a bypass backup valve 10 is set at the front end of the front valve and the rear end of the rear valve through a bypass pipeline.

[0023] The nitrogen purging process includes: a nitrogen purging line 11, a check valve 12, and a manual valve 13; one end of the nitrogen purging line 11 is connected to the position between the pressure regulating valve 9 of the nitrogen line 11 and its downstream valve in the nitrogen replenishment process, and the other end is connected to the position between the safety valve 6 and its downstream valve.

[0024] The check valve on the nitrogen purging line 11 is located near the nitrogen line 7. The front end of the check valve 12 is a manual valve 13, which is used to control the gas flow. The check valve 12 is designed to prevent the flare gas and the gas in the butadiene tank 1 from flowing back into the nitrogen pipeline.

[0025] The nitrogen purging line 11 is connected using a Φ12 instrument duct.

[0026] In another embodiment of this utility model, two auxiliary cross lines 14 for flare discharge networks are arranged parallel to each other on the side branch of the horizontal branch pipeline 3 at the top of the butadiene tank 1. Both auxiliary cross lines 14 are connected to the flare discharge pipeline 2. Safety angle valves 15 are respectively installed on the two auxiliary cross lines 14, and control valves are respectively installed before and after each safety angle valve 15.

[0027] When the safety valve 6 of the flare exhaust cross-line unit in the process system cannot be adjusted, the safety angle valve 15 on the other auxiliary cross-line 14 can be switched to open. When the system pressure is low, the safety valve 6 of the flare exhaust cross-line unit will open when the pressure is 0.4 MPa, and the safety angle valve 15 on the auxiliary cross-line 14 will open when the pressure is 0.5 MPa. It should be noted that both auxiliary processes of the process system and the flare exhaust cross-line unit process are in operation. The safety angle valve 15 in the auxiliary process will not open if the pressure is less than 0.5 MPa.

[0028] In each embodiment of this solution, the purging process of the safety valve outlet pipeline purging system is as follows:

[0029] During normal operation of butadiene tank 1, the rear valve of safety valve 6, the manual valve 13 on nitrogen purging line 11, and the rear valve of pressure regulating valve 9 on nitrogen line 7 are opened in sequence. External nitrogen enters nitrogen line 7 and then nitrogen purging line 11. After exiting nitrogen purging line 11, it enters from the rear end of safety valve 6, thereby realizing continuous purging of the outlet of safety valve 6 by low-pressure nitrogen.

[0030] This solution enables continuous purging of the outlet pipeline of safety valve 6. This is to prevent residual butadiene in the pipeline from being polymerized and causing a safety accident after the safety valve trips. It also saves nitrogen and minimizes costs while ensuring safety.

[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

Claims

1. A butadiene safety valve outlet pipeline purging system, characterized in that, include: The butadiene tank includes a nitrogen replenishment process at its top, a flare purging unit, a flare purging line, a safety valve assembly, and a nitrogen purging process. The butadiene tank top has a pipeline leading out and connected to a horizontal branch pipeline. One side branch of the horizontal branch pipeline is connected to the flare purging line via the flare purging unit, and the gas is then supplied to the flare network. A safety valve assembly is installed on the flare purging unit. The nitrogen replenishment process is connected to the horizontal branch pipeline in the same direction as the flare purging unit. The nitrogen replenishment process is connected to the safety valve assembly via a nitrogen purging process.

2. The butadiene safety valve outlet pipeline purging system according to claim 1, characterized in that: The flare discharge line unit includes a line and a control valve. A safety valve assembly is installed before and after the control valve via a bypass pipeline. The safety valve assembly includes a safety valve and its upstream and downstream valves. The downstream valve of the safety valve is directed towards the outlet of the safety valve.

3. The butadiene safety valve outlet pipeline purging system according to claim 1, characterized in that: The nitrogen replenishment process includes: a nitrogen pipeline, a pressure regulating valve group, and a check valve; a check valve is installed at the front end of the pressure regulating valve group, and the pressure regulating valve group includes: a pressure regulating valve and its front valve and rear valve, and a bypass backup valve is installed at the front end of the front valve and the rear end of the rear valve through a bypass pipeline.

4. The butadiene safety valve outlet pipeline purging system according to claim 1, characterized in that: The nitrogen purging process includes: a nitrogen purging pipeline, a check valve, and a manual valve; one end of the nitrogen purging pipeline is connected between the pressure regulating valve of the nitrogen pipeline in the nitrogen replenishment process and its downstream valve, and the other end is connected between the safety valve and its downstream valve.

5. A butadiene safety valve outlet pipeline purging system according to claim 4, characterized in that: The check valve on the nitrogen purging line is located near the nitrogen line, and the front end of the check valve is a manual valve.

6. A butadiene safety valve outlet pipeline purging system according to claim 4, characterized in that: The nitrogen purging line is connected using a Φ12 instrument duct.

7. A butadiene safety valve outlet pipeline purging system according to claim 1, characterized in that: On the other side of the horizontal branch pipeline at the top of the butadiene tank, two auxiliary cross lines for the flare discharge network are installed in parallel. Both auxiliary cross lines are connected to the flare discharge pipeline. Safety angle valves are installed on the two auxiliary cross lines respectively, and control valves are installed before and after each safety angle valve.

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