Highly toxic exhaust gas absorption system

Abstract

This utility model relates to the technical field of exhaust gas absorption systems, specifically a highly toxic exhaust gas absorption system, including an absorption tower one, which is connected to an exhaust gas inlet pipe, and the exhaust gas outlet at the top of the absorption tower one is connected to the exhaust gas inlet of an absorption tower two; the exhaust gas outlet at the top of the absorption tower two is connected to one end of a fan duct, the other end of which is connected to a high-altitude exhaust chimney, and an induced draft fan is connected to the fan duct; bypass pipes are connected in parallel at both ends of the fan duct, and a rupture disc is connected inside the bypass pipe; differential pressure transmitters are connected to the bypass pipe on both sides of the rupture disc; this utility model can prevent overpressure damage by causing the rupture disc to break open and the exhaust gas to be discharged from the bypass pipe after the induced draft fan at the top of the absorption tower stops operating and causes the system to overpressure; it can monitor the pressure changes in the exhaust gas system in real time, and simultaneously monitor the integrity of the rupture disc.

Description

Technical Field

[0001] This utility model relates to the technical field of exhaust gas absorption systems, specifically a highly toxic exhaust gas absorption system. Background Technology

[0002] After the acidic exhaust gas from industrial production processes is treated in an absorption tower, the non-condensable gases are finally discharged at high altitude through an induced draft fan. However, when the ambient temperature is low, the condensable components in the non-condensable gases are prone to condensate buildup inside the fan casing, leading to abnormal fan shutdown. During fan restart, to prevent fan current overload, the fan inlet valve must be closed. If the fan cannot be restarted immediately for various reasons, and the exhaust gas continues to enter the absorption tower for absorption, the non-condensable gases in the system will continue to accumulate, which can easily cause overpressure damage to the exhaust gas system, leading to equipment damage and toxic gas leaks, posing a serious threat to personnel safety and the environment. Utility Model Content

[0003] The main objective of this invention is to provide a highly toxic exhaust gas absorption system to solve the problem in the prior art where the system is prone to overpressure damage during the period from the shutdown to the restoration of the fan at the top of the absorption tower, which in turn leads to equipment damage and toxic gas leakage.

[0004] To achieve the above objectives, this utility model provides a highly toxic exhaust gas absorption system, including an absorption tower one, which is connected to an exhaust gas inlet pipe, and the exhaust gas outlet at the top of the absorption tower one is connected to the exhaust gas inlet of an absorption tower two; the exhaust gas outlet at the top of the absorption tower two is connected to one end of a fan duct, the other end of the fan duct is connected to a high-altitude exhaust chimney, and an induced draft fan is connected to the fan duct; bypass pipes are connected in parallel at both ends of the fan duct, and rupture discs are connected inside the bypass pipes; differential pressure transmitters are connected to the bypass pipes on both sides of the rupture discs.

[0005] Furthermore, a U-shaped drain pipe is provided on the bypass pipe near the high-pressure side of the rupture disc; the lowest end of the drain pipe is connected to an external drain pipe, and an external drain valve is connected to the external drain pipe.

[0006] Furthermore, absorption tower one is connected to an inlet alkali pipe one and an outlet alkali pipe one, and an inlet alkali pipe one is connected to a heat exchanger one for cooling the liquid inside the inlet alkali pipe one; absorption tower two is connected to an inlet alkali pipe two and an outlet alkali pipe two, and an inlet alkali pipe two is connected to a heat exchanger two for cooling the liquid inside the inlet alkali pipe two.

[0007] Furthermore, the first inlet alkali pipe, the first outlet alkali pipe, the second inlet alkali pipe, and the second outlet alkali pipe are all connected to a circulating alkali tank.

[0008] Furthermore, the top of the circulating alkali tank is connected to the tail gas outlet of the absorption tower 1 via a vent pipe.

[0009] Furthermore, the circulating alkali tank is connected to the fresh alkali tank via a pipeline.

[0010] This invention, by incorporating a rupture disc, allows the exhaust gas to escape through the bypass pipe after the induced draft fan at the top of the absorption tower stops operating, thus preventing damage from overpressure. Furthermore, by installing a differential pressure transmitter, the pressure changes within the exhaust gas system can be monitored in real time, while simultaneously monitoring the integrity of the rupture disc.

[0011] This invention, by setting up a drain pipe and an external drain pipe, can effectively prevent liquid accumulation in the pipeline, avoid uneven pressure or corrosion failure of the rupture disc due to liquid accumulation, thereby ensuring that the rupture disc can reliably function in emergency situations, and further improve the safety and stability of the exhaust gas system.

[0012] This invention, by setting up heat exchanger one and heat exchanger two, enables the cooling water and alkaline solution to exchange heat, effectively absorbing the heat generated by the neutralization reaction of the exhaust gas, avoiding the overheating and overpressure of the circulating alkaline solution due to heat accumulation, thereby ensuring the stable operation of the exhaust gas absorption system and improving the safety and reliability of the entire system. Attached Figure Description

[0013] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0014] Figure 1 A partial structural diagram of an embodiment of a highly toxic exhaust gas absorption system. Figure 1 ; Figure 2 A partial structural diagram of an embodiment of a highly toxic exhaust gas absorption system. Figure 2 ; In the diagram: 1. Absorption Tower 1; 2. Absorption Tower 2; 3. Inlet Gas Pipe; 4. Fan Pipeline; 5. Chimney; 6. Exhaust Fan; 7. Rupture Disc; 8. Differential Pressure Transmitter; 9. Outlet Pipe; 10. Outlet Valve; 11. Inlet Alkali Pipe 1; 12. Outlet Alkali Pipe 1; 13. Heat Exchanger 1; 14. Inlet Alkali Pipe 2; 15. Outlet Alkali Pipe 2; 16. Heat Exchanger 2; 17. Circulating Alkali Tank; 18. Vent Pipe; 19. Drainage Pipe; 20. Fresh Alkali Tank; 21. Bypass Pipe. Detailed Implementation

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0016] like Figures 1 to 2As shown, according to an embodiment of this utility model, a highly toxic exhaust gas absorption system is provided for absorbing acidic gases such as chlorine and phosgene in exhaust gas. The system includes an absorption tower 1 and an absorption tower 2. The absorption tower 1 is connected to an exhaust gas inlet pipe 3, and the exhaust gas outlet at the top of the absorption tower 1 is connected to the exhaust gas inlet of the absorption tower 2. The exhaust gas outlet at the top of the absorption tower 2 is connected to one end of a fan duct 4. The other end of the fan duct 4 is connected to a high-altitude exhaust chimney 5, and an induced draft fan 6 is connected to the fan duct 4. A bypass pipe 21 is connected in parallel to both ends of the fan duct 4. A rupture disc 7 is connected inside the bypass pipe 21; the rupture disc 7 is a positive arched slit type rupture disc. Differential pressure transmitters 8 are connected to the bypass pipe 21 at positions on both sides of the rupture disc 7; the differential pressure transmitters 8 are split-type diaphragm-sealed differential pressure transmitters.

[0017] By installing a rupture disc 7, the system can be overpressurized after the exhaust fan at the top of the absorption tower stops operating, causing the rupture disc 7 to break open and the exhaust gas to enter the chimney through the bypass pipe 21 for discharge, thus avoiding damage from overpressure. By installing a differential pressure transmitter 8, the pressure changes in the exhaust gas system can be monitored in real time, and the integrity of the rupture disc 7 can also be monitored. Under normal circumstances, it is a closed circuit, and the differential pressure transmitter 8 is showing a reading. After the rupture disc breaks, it becomes a closed circuit, and the reading disappears. At this time, it is necessary to check whether there is any abnormality in the rupture disc or the system.

[0018] A U-shaped drain pipe 19 is provided on the bypass pipe 21 near the high-pressure side of the rupture disc 7; the lowest end of the drain pipe 19 is connected to an external drain pipe 9, and an external drain valve 10 is connected to the external drain pipe 9; by setting the drain pipe 19 and the external drain pipe 9, the accumulation of liquid in the pipeline can be effectively prevented, and the rupture disc can be prevented from being under uneven pressure or corroded and failing due to liquid accumulation, thereby ensuring that the rupture disc 7 can play a reliable role in an emergency, and further improving the safety and stability of the exhaust gas system.

[0019] Absorption tower 1 is connected to an inlet alkali solution pipe 11 at the top and an outlet alkali solution pipe 12 at the bottom. A heat exchanger 13 for cooling the liquid inside the inlet alkali solution pipe 11 is connected to the inlet alkali solution pipe 11. Absorption tower 2 is connected to an inlet alkali solution pipe 24 at the top and an outlet alkali solution pipe 25 at the bottom. A heat exchanger 26 for cooling the liquid inside the inlet alkali solution pipe 24 is connected to the inlet alkali solution pipe 24. Heat exchangers 13 and 26 are also connected to a circulating water network, and the circulating water serves as cooling water for heat exchange with the alkali solution.

[0020] By setting up heat exchanger 13 and heat exchanger 26, cooling water and alkali solution can be used for heat exchange, effectively absorbing the heat generated by the tail gas neutralization reaction, avoiding overheating and overpressure of the circulating alkali solution due to heat accumulation, thereby ensuring the stable operation of the tail gas absorption system and improving the safety and reliability of the entire system.

[0021] In some embodiments, the first alkaline solution inlet pipe 11, the first alkaline solution outlet pipe 12, the second alkaline solution inlet pipe 14, and the second alkaline solution outlet pipe 15 are all connected to a circulating alkaline solution tank 17; the circulating alkaline solution tank 17 is connected to a nitrogen pipeline network, and the nitrogen protective gas maintains the pressure inside the circulating alkaline solution tank 17, thereby improving safety.

[0022] In some embodiments, the top of the circulating alkali tank 17 is connected to the tail gas outlet of the absorption tower 1 via a vent pipe 18. The function of the vent pipe 18 is to prevent toxic gases from entering the circulating alkali tank 17 with the circulating alkali and then being discharged into the atmosphere, and to connect the vent of the circulating alkali tank 17 to the absorption tower to form a closed-loop system.

[0023] In some embodiments, the circulating alkali tank 17 is connected to a fresh alkali tank 20 via a pipeline; the fresh alkali tank 20 is connected to the demineralized water pipeline network and the caustic soda pipeline network, and can be equipped with a caustic soda solution of a certain concentration in the fresh alkali tank 20 to replenish the circulating alkali tank 17.

[0024] In some embodiments, the chimney 5 is connected to a wastewater tank via a drain pipe to drain liquids such as condensate and rainwater from the chimney 5; this prevents the condensate and rainwater from flowing back into the pipe, forming a liquid seal that blocks the pipe and ultimately causes overpressure in the system.

[0025] The working principle of the above embodiments is as follows: The alkaline solution is introduced from the circulating alkaline solution tank 17 into the absorption tower 1 and the absorption tower 2 to absorb the toxic gases in the tail gas. The tail gas passes through the absorption tower 1 and the absorption tower 2 in sequence. After the toxic gases in the tail gas are removed, it is finally discharged from the chimney 5.

[0026] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A highly toxic tail gas absorption system comprising an absorption tower (1), characterized in that, The first absorption tower (1) is connected to the exhaust gas inlet pipe (3), and the exhaust gas outlet at the top of the first absorption tower (1) is connected to the exhaust gas inlet of the second absorption tower (2); the exhaust gas outlet at the top of the second absorption tower (2) is connected to one end of the fan pipe (4), and the other end of the fan pipe (4) is connected to the high-altitude exhaust chimney (5), and the fan pipe (4) is connected to the induced draft fan (6); the two ends of the fan pipe (4) are connected in parallel to the bypass pipe (21), and the bypass pipe (21) is connected to the rupture disc (7); the bypass pipe (21) is connected to the differential pressure transmitter (8) on both sides of the rupture disc (7).

2. The highly toxic exhaust gas absorption system according to claim 1, wherein A U-shaped drain pipe (19) is provided on the bypass pipe (21) near the high-pressure side of the rupture disc (7); the lowest end of the drain pipe (19) is connected to an external drain pipe (9), and an external drain valve (10) is connected to the external drain pipe (9).

3. The highly toxic exhaust gas absorption system according to claim 1, wherein The first absorption tower (1) is connected to an inlet alkali pipe (11) and an outlet alkali pipe (12). A heat exchanger (13) for cooling the liquid in the inlet alkali pipe (11) is connected to the inlet alkali pipe (11). The second absorption tower (2) is connected to an inlet alkali pipe (24) and an outlet alkali pipe (25). A heat exchanger (26) for cooling the liquid in the inlet alkali pipe (24) is connected to the inlet alkali pipe (24).

4. The highly toxic exhaust gas absorption system according to claim 3, wherein The first alkali inlet pipe (11), the first alkali outlet pipe (12), the second alkali inlet pipe (14), and the second alkali outlet pipe (15) are all connected to a circulating alkali tank (17).

5. The highly toxic exhaust gas absorption system as described in claim 4, characterized in that, The top of the circulating alkali tank (17) is connected to the tail gas outlet of the absorption tower (1) via a vent pipe (18).

6. The highly toxic exhaust gas absorption system according to claim 4, wherein The circulating alkali tank (17) is connected to the fresh alkali tank (20) via a pipe.

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