Safety interlocking automatic device for negative pressure working condition

Abstract

The utility model discloses a safe interlock automatic control device of negative pressure working condition, it includes rectifying column, and rectifying column side surface is provided with pressure sensor no.

Description

Technical Field

[0001] This utility model relates to the field of negative pressure system technology, and in particular to a safety interlocking automatic control device for negative pressure working conditions. Background Technology

[0002] In chemical production, negative pressure systems are essential for many technological applications, such as vacuum distillation of high-boiling-point materials. In the operation of negative pressure systems for flammable and explosive materials, negative pressure control is particularly crucial. If leaks occur at any dynamic or static sealing points, air entering the negative pressure system can form an explosive mixture, posing a significant risk of flash explosion upon encountering an ignition source such as static electricity. Therefore, it is imperative to implement safety self-control and interlocking protection for flammable and explosive negative pressure systems.

[0003] The working principle of the existing negative pressure condition safety interlock automatic control system is as follows: when the system pressure is high (the negative pressure value is too small), the DCS interlock closes the feed switch valve. Although it can ensure that the feed source is cut off when the negative pressure is out of control, it cannot guarantee the safety protection of air and flammable and explosive materials entering the system. Utility Model Content

[0004] The purpose of this utility model is to solve at least one of the technical problems existing in the prior art, and to provide a safety interlocking automatic control device for negative pressure conditions. By setting corresponding detection instruments and valves in the distillation column system, and using a distributed control system (DCS system) to form an automatic control loop and an interlocking loop, the automatic control and safety interlocking of the distillation column pressure are realized, so that the entire process system is in a safe state. While ensuring stable system pressure control, it avoids the consequences of flash explosion accidents, personal injury, property damage, and environmental pollution caused by leakage of sealing surfaces and air entering flammable and explosive systems.

[0005] This utility model also provides a safety interlock automatic control device with the above-mentioned negative pressure working condition, including: a distillation column, a pressure sensor 1 and a pressure sensor 2 are provided on the side surface of the distillation column, a temperature sensor is provided on the side surface of the distillation column, a feed pipeline is fixedly connected to the side surface of the distillation column, a feed switch valve is fixedly connected to the end of the feed pipeline away from the distillation column, and a nitrogen replenishment switch valve is fixedly connected to the end of the feed pipeline away from the distillation column;

[0006] A condenser is fixedly connected to the top of the distillation column. The condenser is fixedly connected to an exhaust line via an exhaust valve. A vacuum pump is fixedly connected to the end of the exhaust line furthest from the exhaust valve. A reboiler is fixedly connected to the distillation column via a pipeline. The reboiler is fixedly connected to a steam feed line via a steam valve. A steam condensate discharge line is fixedly connected to the surface of the reboiler. These components enable automatic pressure control and safety interlocking of the distillation column, ensuring the entire process system remains safe. This guarantees stable system pressure control and prevents flash explosions, personal injury, property damage, and environmental pollution caused by leaks at sealing surfaces or air entering flammable and explosive systems.

[0007] According to the present invention, a safety interlocking automatic control device for negative pressure operation includes a refrigerant inlet pipeline fixedly connected to the side surface of the condenser, and a refrigerant outlet pipeline fixedly connected to the side surface of the condenser. Cooling refrigerant is fed into the condenser through the refrigerant inlet pipeline, flows through the condenser and absorbs heat, and is then discharged from the refrigerant outlet pipeline.

[0008] According to the safety interlocking automatic control device for negative pressure operation described in this utility model, a discharge pipeline is fixedly connected to the side surface of the distillation column, and a receiving tank is fixedly connected to the end of the discharge pipeline away from the distillation column. The purified material is discharged from the discharge pipeline into the receiving tank for collection.

[0009] According to the present invention, a safety interlocking automatic control device for negative pressure conditions includes a vacuum pump exhaust line fixedly connected to the end of the vacuum pump away from the exhaust line, and a gas outlet tank fixedly connected to the end of the vacuum pump exhaust line away from the vacuum pump. The extracted gas is sent into the gas outlet tank through the vacuum pump exhaust line.

[0010] According to the present invention, a safety interlocking automatic control device for negative pressure operation includes a three-way feed line, and a raw material tank is fixedly connected to the end of the feed switch valve away from the feed line. The raw material in the raw material tank is fed into the distillation column through the feed line.

[0011] According to the safety interlock automatic control device for negative pressure operation described in this utility model, the refrigerant inlet pipeline is located above the refrigerant outlet pipeline, and the steam condensate discharge pipeline is located below the steam inlet pipeline. This facilitates the discharge of refrigerant and condensate.

[0012] According to the present invention, a safety interlocking automatic control device for negative pressure operation includes a pressure sensor one located at the top of the distillation column, a pressure sensor two located at the top of the distillation column, and a temperature sensor located near the bottom of the distillation column. Pressure sensors one and two provide feedback on the pressure information at the top of the distillation column, while the temperature sensor provides feedback on the temperature information at the bottom of the distillation column.

[0013] Beneficial effects:

[0014] The safety interlock automatic control device for negative pressure operation in this technical solution enables automatic control and safety interlock of the distillation column pressure, keeping the entire process system in a safe state. It ensures stable system pressure control while avoiding consequences such as flash explosions, personal injury, property damage, and environmental pollution caused by leaks in the sealing surface or air entering the flammable and explosive system. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0016] Figure 1 This is a front view of the overall structure of the safety interlocking automatic control device for negative pressure conditions of this utility model;

[0017] Figure 2 This is a rear view of the overall structure of the safety interlocking self-control device for negative pressure conditions according to this utility model;

[0018] Figure 3 This is a structural diagram of the reboiler of the safety interlock automatic control device for negative pressure conditions according to this utility model;

[0019] Figure 4 This is a flowchart of the safety interlocking automatic control device for negative pressure conditions according to this utility model.

[0020] Legend:

[0021] 1. Distillation column; 2. Feed line; 3. Discharge line; 4. Exhaust line; 5. Vacuum pump exhaust line; 6. Raw material tank; 7. Collection tank; 8. Gas outlet tank; 9. Reboiler; 10. Condenser; 11. Steam feed line; 12. Steam condensate discharge line; 13. Refrigerant feed line; 14. Refrigerant discharge line; 15. Pressure sensor one; 16. Pressure sensor two; 17. Temperature sensor; 18. Feed switch valve; 19. Steam switch valve; 20. Gas outlet switch valve; 21. Nitrogen replenishment switch valve; 22. Vacuum pump. Detailed Implementation

[0022] Reference Figure 1-4This utility model provides a safety interlocking automatic control device for negative pressure conditions, comprising: a distillation column 1, a pressure sensor 15 disposed on the side surface of the distillation column 1 and located at the top of the distillation column 1, a pressure sensor 16 disposed on the side surface of the distillation column 1 and located at the top of the distillation column 1, a temperature sensor 17 disposed on the side surface of the distillation column 1 and located near the bottom of the distillation column 1, a feed line 2 fixedly connected to the side surface of the distillation column 1, a feed switch valve 18 fixedly connected to the end of the feed line 2 away from the distillation column 1, and a nitrogen replenishment switch valve 21 fixedly connected to the end of the feed line 2 away from the distillation column 1;

[0023] A condenser 10 is fixedly connected to the top of the distillation column 1. The condenser 10 is fixedly connected to an exhaust line 4 via an exhaust valve 20. A vacuum pump 22 is fixedly connected to the end of the exhaust line 4 away from the exhaust valve 20. A reboiler 9 is fixedly connected to the distillation column 1 via a pipeline. A steam feed line 11 is fixedly connected to the reboiler 9 via a steam valve 19. A steam condensate discharge line 12 is fixedly connected to the surface of the reboiler 9. The steam condensate discharge line 12 is located below the steam feed line 11.

[0024] Specifically, temperature sensor 17, pressure sensor one 15 and pressure sensor two 16, feed switch valve 18, steam switch valve 19, nitrogen replenishment switch valve 21, and exhaust switch valve 20 are electrically connected to the distributed control system (DCS system). The inlet and outlet of reboiler 9 are both connected to distillation column 1 via pipelines. This allows the liquid mixture in distillation column 1 to be partially vaporized by steam input from steam feed line 11 after entering reboiler 9, and then returned to distillation column 1. The condensate produced after the steam absorbs heat is then cooled by the steam cooler. Condensate is discharged through pipeline 12. High-limit alarms are preset for pressure sensors 15 and 16 in the DCS system, and these sensors continuously feed back pressure information from the top of distillation column 1 to the DCS system. Temperature sensor 17 continuously feeds back temperature information from the bottom of distillation column 1 to the DCS system. Pressure sensor 15 at the top of distillation column 1 and vacuum pump 22 are automatically controlled via a frequency converter. When the pressure at the top of the column rises, the frequency of vacuum pump 22 automatically increases; when the pressure at the top of the column falls, the frequency of vacuum pump 22 automatically decreases. When temperature sensor 17 detects that the temperature of the bottom of distillation column 1 exceeds the high-high limit, an interlock is triggered, and the DCS system interlocks and closes the bottom steam valve 19. When pressure sensor 16 at the top of distillation column 1 detects that the pressure exceeds the high-high limit, an interlock is triggered, and the DCS system interlocks and closes the feed valve 18, closes the steam valve 19, and opens the emergency nitrogen replenishment valve 21, activating nitrogen purging protection in the system. When pressure sensor 16 detects that the pressure at the top of the tower has reached the high pressure limit, the nitrogen replenishment switch valve 21 is closed to prevent the equipment from overpressured.

[0025] A refrigerant feed line 13 is fixedly connected to the side surface of the condenser 10, and a refrigerant discharge line 14 is fixedly connected to the side surface of the condenser 10. The refrigerant feed line 13 is located above the refrigerant discharge line 14. A discharge line 3 is fixedly connected to the side surface of the distillation column 1. A receiving tank 7 is fixedly connected to the end of the discharge line 3 away from the distillation column 1. A vacuum pump exhaust line 5 is fixedly connected to the end of the vacuum pump 22 away from the exhaust line 4. An exhaust tank 8 is fixedly connected to the end of the vacuum pump exhaust line 5 away from the vacuum pump 22. The feed line 2 is a three-way pipe. A raw material tank 6 is fixedly connected to the end of the feed switch valve 18 away from the feed line 2.

[0026] Specifically, the condenser 10 is equipped with a refrigerant inlet line 13 and a refrigerant outlet line 14. The refrigerant is introduced into the condenser 10 through the refrigerant inlet line 13, and during the flow through the condenser 10, it cools the vapor mixture rising to the top of the column. After absorbing heat, it is discharged from the refrigerant outlet line 14. After the raw material is purified by multi-stage distillation in the distillation column 1, the purified compound is sent to the collection tank 7 through the outlet line 3 for collection. When the pressure at the top of the column rises, the vacuum pump 22 will pump the gas through the vacuum pump. The exhaust line 5 is fed into the outlet tank 8 to reduce the pressure at the top of the column. The feed line 2 is a three-way pipe with three ports connected to the distillation column 1, the feed switch valve 18, and the nitrogen replenishment switch valve 21, respectively. This allows the raw material in the raw material tank 6 to enter the distillation column 1 through the feed line 2 and the feed switch valve 18. The feed switch valve 18 is used to control the delivery of the raw material. At the same time, when the pressure at the top of the distillation column 1 is detected to exceed the high pressure limit, the nitrogen replenishment switch valve 21 can be opened to inject nitrogen into the distillation column 1 through the feed line 2 to provide nitrogen protection.

[0027] Working Principle: The DCS system presets high-limit alarms for pressure sensors 15 and 16, and these sensors continuously feed back pressure information from the top of distillation column 1 to the DCS system. Temperature sensor 17 continuously feeds back temperature information from the bottom of distillation column 1 to the DCS system. Pressure sensor 15 at the top of distillation column 1 and vacuum pump 22 are automatically controlled via a frequency converter. When the pressure at the top of the column rises, the frequency of vacuum pump 22 automatically increases; when the pressure at the top of the column falls, the frequency of vacuum pump 22 automatically decreases. When temperature sensor 17 detects that the temperature of the bottom of distillation column 1 exceeds the high-high limit, it triggers an interlock, and the DCS system interlocks and closes the bottom steam valve 19. When pressure sensor 16 at the top of distillation column 1 detects that the pressure exceeds the high-high limit, it triggers an interlock, and the DCS system interlocks and closes the feed valve 18, closes the steam valve 19, and opens the emergency nitrogen replenishment valve 21, activating nitrogen purging protection in the system. When pressure sensor 16 detects that the pressure at the top of the tower has reached the high pressure limit, the nitrogen replenishment switch valve 21 is closed to prevent the equipment from overpressured.

Claims

1. A safety interlocking automatic control device for negative pressure conditions, characterized in that, include: A distillation column (1) is provided with a pressure sensor 1 (15) on its side surface, a pressure sensor 2 (16) on its side surface, a temperature sensor (17) on its side surface, a feed line (2) fixedly connected to the side surface of the distillation column (1), a feed switch valve (18) fixedly connected to the end of the feed line (2) away from the distillation column (1), and a nitrogen replenishment switch valve (21) fixedly connected to the end of the feed line (2) away from the distillation column (1). A condenser (10) is fixedly connected to the top of the distillation column (1). The condenser (10) is fixedly connected to an exhaust line (4) via an exhaust valve (20). A vacuum pump (22) is fixedly connected to the end of the exhaust line (4) away from the exhaust valve (20). A reboiler (9) is fixedly connected to the distillation column (1) via a pipeline. A steam feed line (11) is fixedly connected to the reboiler (9) via a steam valve (19). A steam condensate discharge line (12) is fixedly connected to the surface of the reboiler (9).

2. The safety interlocking and automatic control device for negative pressure working condition according to claim 1, characterized in that, A refrigerant inlet line (13) is fixedly connected to the side surface of the condenser (10), and a refrigerant outlet line (14) is fixedly connected to the side surface of the condenser (10).

3. The safety interlocking and automatic control device for negative pressure working condition according to claim 1, characterized in that, A discharge pipeline (3) is fixedly connected to the side surface of the distillation column (1), and a receiving tank (7) is fixedly connected to the end of the discharge pipeline (3) away from the distillation column (1).

4. The safety interlock automatic control device for negative pressure working condition according to claim 1, characterized in that, The vacuum pump (22) is fixedly connected to a vacuum pump exhaust line (5) at the end away from the exhaust line (4), and an exhaust tank (8) is fixedly connected to the end of the vacuum pump exhaust line (5) away from the vacuum pump (22).

5. The safety interlock automatic control device for negative pressure working condition according to claim 1, characterized in that, The feed line (2) is a three-way pipe, and the feed switch valve (18) is fixedly connected to the raw material tank (6) at the end away from the feed line (2).

6. The safety interlock automatic control device for negative pressure working condition according to claim 2, characterized in that, The refrigerant feed line (13) is located above the refrigerant discharge line (14), and the steam condensate discharge line (12) is located below the steam feed line (11).

7. The safety interlocking automatic control device for negative pressure conditions according to claim 1, characterized in that, The first pressure sensor (15) is located at the top of the distillation column (1), the second pressure sensor (16) is located at the top of the distillation column (1), and the temperature sensor (17) is located near the bottom of the distillation column (1).

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