D-101 feed evaporation tank polymerization inhibitor injection control device

Abstract

The utility model relates to evaporating tank technical field especially is related to a kind of D-101 feed evaporating tank polymerization inhibitor injection control device.The control device, including polymerization inhibitor pipeline and auxiliary pump;The inlet end of the polymerization inhibitor pipeline is connected with the outlet end of auxiliary pump, and the outlet end of polymerization inhibitor pipeline is communicated with the feed pipeline of feed evaporating tank by one-way valve;First protection valve, regulating valve and second protection valve are sequentially provided on the polymerization inhibitor pipeline along the moving direction of polymerization inhibitor.The purpose of the control device of the utility model is to increase Butaclean4626 polymerization inhibitor adding system in the feed pipeline of feed evaporating tank, using existing auxiliary pump P-517 pump to inject polymerization inhibitor Butaclean4626 into the feed pipeline of feed evaporating tank, so that polymerization inhibitor passes through first protection valve, regulating valve, second protection valve and one-way valve, enters D-101 feed evaporating tank and plays the role of inhibiting polymerization.

Description

Technical Field

[0001] This utility model relates to the field of evaporator technology, and in particular to a polymerization inhibitor injection control device for a D-101 feed evaporator. Background Technology

[0002] Butadiene is a chemically reactive conjugated diene. Under certain conditions, it readily forms end-group polymers and peroxide self-polymers within equipment and pipelines. These polymers are highly unstable and can rapidly decompose and explode upon impact or rapid heating, initiating butadiene end-group polymerization to form a white, honeycomb-like solid. The formation of butadiene end-polymers is a free radical chain growth process with high heat of polymerization. Once polymerization occurs, the heat cannot be dissipated quickly, which in turn accelerates the generation of free radicals and chain growth reactions, accelerating polymerization and creating a vicious cycle, ultimately leading to explosive polymerization. The polymer particles continuously increase in size and extend outward until they fill the equipment. When butadiene end-polymers fill the equipment or form large polymer masses, some active centers are shielded inside the solid particles. For linear butadiene molecules, they can penetrate the polymerized macromolecular rings to enter the solid interior, while polymerization inhibitor molecules with large molecular groups have difficulty entering the solid interior. Therefore, once polymers are formed, the effect of polymerization inhibitors is quite limited. Therefore, it is necessary to strictly control the location and amount of polymerization inhibitor added to ensure that butadiene does not generate butadiene peroxide and end polymers in the equipment.

[0003] In the butadiene plant, the feed evaporator reboiler operates at a low temperature (49°C) and has a low butadiene content (around 42%wt). Theoretically, under normal circumstances, polymer blockage should be less likely to occur during long-term operation. However, in actual use, severe blockage of the bottom discharge filter and polymer blockage of the evaporator reboiler have occurred, resulting in reduced heating efficiency and hindered plant operation, significantly shortening the plant's operating cycle.

[0004] Polymer formation in butadiene plants is typically related to factors such as the mixed C4 composition, operating temperature, material residence time, oxygen and peroxide content, and the operation of the feed evaporator. The feedstock has a high C5 content, and the content of carbonyl compounds such as acetaldehyde and acetone exceeds 20 ppm. These impurities not only directly accelerate butadiene polymerization but also increase the amount of tar in subsequent extraction units, further intensifying the polymerization reaction. The online oxygen gauge at the top of the feed evaporator frequently shows excessive levels, suggesting oxygen infiltration. Excessive oxygen in the system promotes the formation of peroxide self-polymers from butadiene, providing a catalyst for the polymerization reaction. Excessive oxygen content indirectly leads to increased peroxide content in the system, accelerating polymerization and further amplifying the risk of blockage. Utility Model Content

[0005] In view of this, the present invention provides a D-101 feed evaporator inhibitor injection control device.

[0006] Therefore, the present invention provides the following technical solution: A control device for injecting polymerization inhibitor into a D-101 feed evaporator includes a polymerization inhibitor pipeline and an additive pump; the inlet end of the polymerization inhibitor pipeline is connected to the outlet end of the additive pump, and the outlet end of the polymerization inhibitor pipeline is connected to the feed pipeline of the feed evaporator through a one-way valve; a first protection valve, a regulating valve, and a second protection valve are sequentially arranged on the polymerization inhibitor pipeline along the movement direction of the polymerization inhibitor.

[0007] Furthermore, it also includes an auxiliary pipeline, the inlet end of which is connected to the feed pipeline of the feed evaporator, and the outlet end of which is connected to the polymerization inhibitor pipeline.

[0008] Furthermore, a nozzle is installed at the outlet end of the polymerization inhibitor pipeline. The nozzle is located inside the feed pipeline and is arranged along the material movement direction inside the feed pipeline.

[0009] Furthermore, the first protective valve, the regulating valve, and the second protective valve are connected in parallel to a bypass valve, and a first drain valve is provided on the polymerization inhibitor pipeline between the first protective valve and the regulating valve.

[0010] Furthermore, on the polymerization inhibitor pipeline, an isolation valve is provided on the inlet side near the one-way valve, and a second drain valve is provided on the side near the inlet of the isolation valve.

[0011] Furthermore, a pressure gauge and a first flow meter are installed on the polymerization inhibitor pipeline.

[0012] Furthermore, the auxiliary pipeline is sequentially equipped with a first control valve, a third drain valve, a second flow meter, and a second control valve along the direction of material movement.

[0013] Advantages and positive effects of this utility model: The purpose of this invention is to add a Butaclean 4626 polymerization inhibitor to the feed pipeline of the evaporator. This product is an oil-soluble chain reaction terminator used to terminate free radical polymerization reactions induced by heat, etc. It is highly effective against free radicals in a stable aerobic environment. This prevents forced shutdowns due to clogging of filters, pumps, and related pipes and valves caused by polymer buildup. It reduces damage to equipment, extends equipment operating time, and ensures safe operation.

[0014] The polymerization inhibitor Butaclean 4626 is injected into the feed line of the feed evaporator using the existing auxiliary pump P-517. The polymerization inhibitor then enters the D-101 feed evaporator through the first protection valve, regulating valve, second protection valve and check valve to inhibit polymerization.

[0015] The amount of Butaclean 4626 polymerization inhibitor solution entering tank D-101 is precisely regulated via a control valve. It captures free radicals in the C4 mixture of the consumed raw materials, terminating the butadiene thermal polymerization reaction, thereby controlling the formation of gel-like polymers and extending the unit's operating cycle. This reduces economic losses caused by abnormal shutdowns and the safety hazards associated with butadiene thermal polymerization.

[0016] The check valve can be maintained by closing the first and second protection valves, and the operation is simple. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 The circuit diagram of a D-101 feed evaporator inhibitor injection control device provided by this utility model.

[0019] Figure 2 This utility model Figure 1 Perspective view at point A in the middle.

[0020] In the diagram: 1. Regulating valve; 2. First protective valve; 3. Second protective valve; 4. Bypass valve; 5. Isolation valve; 6. First drain valve; 7. Second drain valve; 8. Check valve; 9. First control valve; 10. Second control valve; 11. Third drain valve; 12. Inhibitor pipeline; 13. Auxiliary pipeline; 14. Feed evaporator; 15. Feed pipeline; 16. Pressure gauge; 17. First flow meter; 18. Second flow meter; 19. Nozzle. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. 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 skilled in the art without creative effort should fall within the protection scope of the present invention.

[0022] This utility model provides a control device for the injection of polymerization inhibitor into a D-101 feed evaporator, such as... Figure 1As shown, it includes an inhibitor pipeline 12 and an additive pump; the inlet end of the inhibitor pipeline 12 is connected to the outlet end of the additive pump, and the outlet end of the inhibitor pipeline 12 is connected to the feed pipeline 15 of the feed evaporator 14 through a one-way valve 8; as shown... Figure 2 As shown, a nozzle 19 is installed at the outlet end of the polymerization inhibitor pipeline 12. The nozzle 19 is located inside the feed pipeline 15 and is arranged along the material movement direction inside the feed pipeline 15.

[0023] like Figure 1 As shown, the polymerization inhibitor pipeline 12 is sequentially equipped with a first protective valve 2, a regulating valve 1, a second protective valve 3, a second drain valve 7, and an isolation valve 5 along the direction of polymerization inhibitor movement. The isolation valve 5 is located on the inlet side of the one-way valve 8. A pressure gauge 16 and a first flow meter 17 are installed on the polymerization inhibitor pipeline 12.

[0024] The first protective valve 2, the regulating valve 1, and the second protective valve 3 are connected in parallel to a bypass valve 4. A first drain valve 6 is provided on the polymerization inhibitor pipeline 12 between the first protective valve 2 and the regulating valve 1.

[0025] It also includes an auxiliary pipeline 13, the inlet end of which is connected to the feed pipeline 15 of the feed evaporator 14, and the outlet end of which is connected to the polymerization inhibitor pipeline 12. The auxiliary pipeline 13 is provided with a first control valve 9, a third drain valve 11, a second flow meter 18, and a second control valve 10 in sequence along the material movement direction.

[0026] Working Principle: The existing additive pump P-517 provides power for the delivery of the polymerization inhibitor, drawing Butaclean 4626 from the storage device and feeding it into the inhibitor pipeline 12. The inhibitor travels along pipeline 12 sequentially through the first protective valve 2, regulating valve 1, second protective valve 3, isolation valve 5, and check valve 8, finally being injected into the material through nozzle 19 installed in the feed pipeline 15. Nozzle 19 is positioned along the material movement direction within the feed pipeline 15 to ensure thorough mixing of the inhibitor and material, enhancing its effectiveness. Check valve 8 prevents material in the feed pipeline 15 from flowing back into the inhibitor pipeline 12, avoiding pipeline contamination and equipment damage.

[0027] The regulating valve 1 is the core control component for the amount of polymerization inhibitor injected. It can precisely adjust the injection flow rate of the polymerization inhibitor according to the operating conditions of the feed evaporator and the characteristics of the material, so as to ensure that the amount of polymerization inhibitor is reasonable, which can effectively inhibit the polymerization reaction and avoid waste.

[0028] The first protective valve 2 and the second protective valve 3 are located on both sides of the regulating valve 1. They are in the open state during normal operation to provide safety protection for the regulating valve 1 and prevent impurities or pressure fluctuations in the pipeline from causing damage to it. When the regulating valve 1 malfunctions, these two valves can be closed to isolate the regulating valve and facilitate maintenance.

[0029] Bypass valve 4 is connected in parallel with first protection valve 2, regulating valve 1, and second protection valve 3. When regulating valve 1 needs maintenance, bypass valve 4 is opened to ensure uninterrupted supply of polymerization inhibitor and maintain normal operation of the unit.

[0030] The first drain valve 6 is located between the first protection valve 2 and the regulating valve 1. Before maintaining the regulating valve 1, opening this valve can drain the polymerization inhibitor in this section of the pipeline, which facilitates maintenance operations.

[0031] Isolation valve 5 is located on the inlet side of check valve 8 and is used to isolate the polymerization inhibitor injection device from feed line 15. When the device needs maintenance or is stopped, isolation valve 5 is closed to prevent the material and polymerization inhibitor from affecting each other. The second drain valve 7 is used to empty the polymerization inhibitor in the injection device. When the device is stopped for maintenance or the polymerization inhibitor is replaced, this valve is opened to drain the residual polymerization inhibitor in the pipeline.

[0032] The pressure gauge 16 and the first flow meter 17 installed on the polymerization inhibitor pipeline 12 monitor the pressure and polymerization inhibitor flow rate in the pipeline in real time. The operator can judge the operating status of the device based on the monitoring data and adjust the opening of the regulating valve 1 in a timely manner to ensure stable polymerization inhibitor injection.

[0033] When abnormal pressure occurs in the polymerization inhibitor pipeline 12 or when additional material mixing samples are needed, the first control valve 9 and the second control valve 10 can be adjusted to allow some material to enter the polymerization inhibitor pipeline 12, balancing the pipeline pressure or for component detection. The second flow meter 18 monitors the material flow rate in the auxiliary pipeline, providing operators with adjustment guidelines; the third drain valve 11 can drain residual material in the auxiliary pipeline, facilitating pipeline maintenance.

[0034] The polymerization inhibitor Butaclean 4626, after precise adjustment, is injected into the feed line 15 and thoroughly mixed with the C4 mixture. The inhibitor molecules rapidly capture free radicals in the material, disrupting the chain reaction process of butadiene's thermal polymerization and terminating the polymerization reaction, thus effectively controlling the formation of gel-like polymers. Through this process, the polymer at the bottom of the feed evaporator is significantly reduced, the viscosity decreases, and the color lightens. This prevents forced shutdowns of filters, pumps, and related pipes and valves due to polymer scale blockage, reduces equipment damage, ensures safe and stable operation of the unit, and extends its operating cycle.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A control device for injecting polymerization inhibitor into a D-101 feed evaporator, characterized in that, It includes an inhibitor pipeline (12) and an additive pump; the inlet end of the inhibitor pipeline (12) is connected to the outlet end of the additive pump, and the outlet end of the inhibitor pipeline (12) is connected to the feed pipeline (15) of the feed evaporator (14) through a one-way valve (8); a first protection valve (2), a regulating valve (1) and a second protection valve (3) are sequentially arranged on the inhibitor pipeline (12) along the moving direction of the inhibitor.

2. The D-101 feed evaporator polymerization inhibitor injection control device according to claim 1, characterized in that, It also includes an auxiliary pipeline (13), the inlet end of which is connected to the feed pipeline (15) of the feed evaporator (14), and the outlet end of the auxiliary pipeline (13) is connected to the polymerization inhibitor pipeline (12).

3. The D-101 feed evaporator polymerization inhibitor injection control device according to claim 1, characterized in that, A nozzle (19) is installed at the outlet end of the polymerization inhibitor pipeline (12). The nozzle (19) is located inside the feed pipeline (15) and is set along the material movement direction inside the feed pipeline (15).

4. The D-101 feed evaporator polymerization inhibitor injection control device according to claim 1, characterized in that, The first protective valve (2), the regulating valve (1), and the second protective valve (3) are connected in parallel to a bypass valve (4), and a first drain valve (6) is provided on the polymer inhibitor pipeline (12) between the first protective valve (2) and the regulating valve (1).

5. The D-101 feed evaporator polymerization inhibitor injection control device according to claim 1, characterized in that, On the polymerization inhibitor pipeline (12), an isolation valve (5) is provided on the side near the inlet of the one-way valve (8), and a second drain valve (7) is provided on the side near the inlet of the isolation valve (5).

6. The D-101 feed evaporator polymerization inhibitor injection control device according to claim 1, characterized in that, A pressure gauge (16) and a first flow meter (17) are installed on the polymerization inhibitor pipeline (12).

7. The D-101 feed evaporator polymerization inhibitor injection control device according to claim 2, characterized in that, The auxiliary pipeline (13) is provided with a first control valve (9), a third drain valve (11), a second flow meter (18), and a second control valve (10) in sequence along the direction of material movement.

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