Safety interlocking system of polymerization kettle for producing polytetrafluoroethylene by suspension method

Abstract

The utility model discloses a safety interlocking system of a polymerization kettle for producing polytetrafluoroethylene by a suspension method, and relates to the technical field of polytetrafluoroethylene production. According to the utility model, through the dispersion instrument control system, when overtemperature and overpressure occur in the polymerization kettle, the first tetrafluoroethylene feed valve, the first steam feed valve and the first condensate water outlet valve are controlled to stop feeding and steam introduction, and the motor is closed to stop stirring; the first chilled water inlet valve, the first chilled water outlet valve and the first emergency emptying valve are opened at the same time, chilled water is introduced into the jacket to further reduce the temperature and pressure of the polymerization kettle, and meanwhile, a part of pressure is released through the emergency emptying pipeline, so that the production is ensured to be in a safe state.

Description

Technical Field

[0001] The utility model relates to the technical field of polytetrafluoroethylene production, in particular to a safety interlocking system of a polytetrafluoroethylene polymerization kettle produced by a suspension method. Background Art

[0002] The suspension method for producing polytetrafluoroethylene is to produce polytetrafluoroethylene by free radical polymerization of tetrafluoroethylene monomer. The production process mainly includes polymerization, crushing, washing, drying and other processes. The polymerization process determines the chemical properties of the product. The reaction equation is: nCF 2 =CF 2 →[-CF 2 -CF 2 -] n .

[0003] In the suspension process of polytetrafluoroethylene production, the polymerization reaction is particularly critical. The raw material polytetrafluoroethylene in the polymerization kettle is a flammable and explosive substance, and the reaction process is an exothermic reaction. Therefore, if the polymerization kettle has an over-temperature and over-pressure accident, it will cause material leakage and even fire and explosion accidents, causing serious personal injury, property loss and environmental pollution. Therefore, in response to this problem, it is necessary to provide a safety interlock system for the suspension process of polytetrafluoroethylene polymerization kettle to ensure the safe production. Utility Model Content

[0004] The technical problem to be solved by the utility model is: to overcome the shortcomings of the prior art and provide a safety interlock system for a polytetrafluoroethylene polymerization kettle for producing polytetrafluoroethylene by a suspension method. Through a distributed instrument control system, when the polymerization kettle is over-temperature and over-pressure occurs, a first polytetrafluoroethylene feed valve, a first steam feed valve and a first condensate outlet valve are controlled, and a motor is closed to stop stirring, and a first chilled water inlet valve, a first chilled water outlet valve and a first emergency vent valve are opened, thereby ensuring that production is in a safe state.

[0005] The technical solution of the utility model is:

[0006] A safety interlock system for a polytetrafluoroethylene polymerization kettle for producing polytetrafluoroethylene by a suspension method, wherein the polymerization kettle is connected with a tetrafluoroethylene feed pipeline and an emergency venting pipeline, the tetrafluoroethylene feed pipeline is provided with a first tetrafluoroethylene feed valve, and the emergency venting pipeline is provided with a first emergency venting valve; the polymerization kettle is provided with a stirrer, and the stirrer is driven by a motor; a jacket is provided outside the polymerization kettle, and the jacket is connected with a steam feed pipeline, a condensed water outlet pipeline, a chilled water inlet pipeline and a chilled water outlet pipeline, the steam feed pipeline is provided with a first steam feed valve, the condensed water outlet pipeline is provided with a first condensed water outlet valve, the chilled water inlet pipeline is provided with a first chilled water inlet valve, and the chilled water outlet pipeline is provided with a first chilled water outlet valve; the polymerization kettle is provided with a first temperature sensor and a first pressure sensor, and the first temperature sensor, the first pressure sensor, the first tetrafluoroethylene feed valve, the first emergency venting valve, the motor, the first steam feed valve, the first condensed water outlet valve, the first chilled water inlet valve and the first chilled water outlet valve are respectively electrically connected to a distributed instrument control system.

[0007] Preferably, the polymerization kettle is provided with a second temperature sensor and a second pressure sensor, a second tetrafluoroethylene feed valve is provided on the tetrafluoroethylene feed pipeline, a second emergency vent valve is provided on the emergency vent pipeline, a second steam feed valve is provided on the steam feed pipeline, a second condensate outlet valve is provided on the condensate outlet pipeline, a second chilled water inlet valve is provided on the chilled water inlet pipeline, and a second chilled water outlet valve is provided on the chilled water outlet pipeline; the second temperature sensor, the second pressure sensor, the second tetrafluoroethylene feed valve, the second emergency vent valve, the motor, the second steam feed valve, the second condensate outlet valve, the second chilled water inlet valve and the second chilled water outlet valve are electrically connected to the safety instrument system respectively.

[0008] Preferably, the tetrafluoroethylene feed line and the emergency vent line are connected to the top of the polymerization kettle.

[0009] Preferably, the steam feed line is connected to the upper part of the jacket.

[0010] Preferably, the condensate outlet pipeline is connected to the lower part of the jacket.

[0011] Preferably, the chilled water inlet pipeline is connected to the lower part of the jacket.

[0012] Preferably, the chilled water outlet pipeline is connected to the upper part of the jacket.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] 1. The utility model uses a decentralized instrument control system. When the polymerization kettle is over-temperature and over-pressured, the first tetrafluoroethylene feed valve, the first steam feed valve and the first condensed water outlet valve are controlled to stop feeding and steam, and the motor is turned off to stop stirring. At the same time, the first chilled water inlet valve, the first chilled water outlet valve and the first emergency vent valve are opened, and chilled water is introduced into the jacket to further reduce the temperature and pressure of the polymerization kettle. At the same time, part of the pressure is released through the emergency vent pipeline, thereby ensuring that the production is in a safe state.

[0015] 2. When an over-temperature and over-pressure accident occurs and the distributed instrument control system does not operate, the second tetrafluoroethylene feed valve, the second steam feed valve and the second condensate outlet valve can be controlled by the safety instrument system to stop feeding and steam, and turn off the motor to stop stirring. At the same time, the second chilled water inlet valve, the second chilled water outlet valve and the second emergency vent valve are opened, and chilled water is introduced into the jacket to further reduce the temperature and pressure of the polymerization kettle. At the same time, part of the pressure is released through the emergency vent pipeline to ensure that production is in a safe state. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The utility model is a structural schematic diagram of a safety interlocking system of a polytetrafluoroethylene polymerization kettle produced by a suspension method.

[0017] In the figure, 1, polymerization kettle; 2, tetrafluoroethylene feed pipeline; 201, first tetrafluoroethylene feed valve; 202, second tetrafluoroethylene feed valve; 3, emergency vent pipeline; 301, first emergency vent valve; 302, second emergency vent valve; 4, agitator; 5, motor; 6, jacket; 7, steam feed pipeline; 701, first steam feed valve; 702, second steam feed valve; 8, condensate outlet pipeline; 801, first condensate outlet valve; 802, second condensate outlet valve; 9, chilled water inlet pipeline; 901, first chilled water inlet valve; 902, second chilled water inlet valve; 10, chilled water outlet pipeline; 1001, first chilled water outlet valve; 1002, second chilled water outlet valve; 11, first temperature sensor; 12, first pressure sensor; 13, second temperature sensor; 14, second pressure sensor. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0019] Example 1

[0020] like Figure 1As shown, this embodiment provides a safety interlock system for a polytetrafluoroethylene polymerization kettle for producing polytetrafluoroethylene by a suspension process, wherein a polytetrafluoroethylene feed pipeline 2 and an emergency venting pipeline 3 are connected to the top of the polymerization kettle 1, a first polytetrafluoroethylene feed valve 201 is provided on the polytetrafluoroethylene feed pipeline 2, and a first emergency venting valve 301 is provided on the emergency venting pipeline 3; the polymerization kettle 1 is provided with a stirrer 4, and the stirrer 4 is driven by a motor 5; a jacket 6 is provided outside the polymerization kettle 1, and the jacket 6 is connected with a steam feed pipeline 7, a condensed water outlet pipeline 8, a chilled water inlet pipeline 9 and a chilled water outlet pipeline 10, wherein the steam feed pipeline 7 and the chilled water outlet pipeline 10 are connected to the upper part of the jacket 6, and the condensed water outlet pipeline 8 and the chilled water inlet pipeline 9 are connected to the lower part of the jacket 6.

[0021] like Figure 1 As shown, the steam feed pipeline 7 is provided with a first steam feed valve 701, the condensate outlet pipeline 8 is provided with a first condensate outlet valve 801, the chilled water inlet pipeline 9 is provided with a first chilled water inlet valve 901, and the chilled water outlet pipeline 10 is provided with a first chilled water outlet valve 1001; the polymerization kettle 1 is provided with a first temperature sensor 11 and a first pressure sensor 12, and the first temperature sensor 11, the first pressure sensor 12, the first tetrafluoroethylene feed valve 201, the first emergency vent valve 301, the motor 5, the first steam feed valve 701, the first condensate outlet valve 801, the first chilled water inlet valve 901 and the first chilled water outlet valve 1001 are electrically connected to the distributed instrument control (DCS) system respectively.

[0022] Working principle:

[0023] The upper limit and high-high limit of the temperature and pressure of the polymerization kettle 1 are preset in the DCS system. During the reaction process, the first temperature sensor 11 and the first pressure sensor 12 respectively feed back the temperature and pressure information of the polymerization kettle 1 to the DCS system in real time. When the first temperature sensor 11 or the first pressure sensor 12 detects that the reaction temperature or pressure of the polymerization kettle 1 reaches the upper limit, the DCS system issues a high limit alarm to remind the staff; when the first temperature sensor 11 or the first pressure sensor 12 detects that the reaction temperature or pressure of the polymerization kettle 1 reaches the upper limit, the DCS system controls the closing of the first tetrafluoroethylene feed valve 201, the first steam feed valve 701 and the first condensed water outlet valve 801, stops feeding and stops passing steam, and closes the motor 5 to stop stirring, and opens the first chilled water inlet valve 901, the first chilled water outlet valve 1001 and the first emergency vent valve 301, passes chilled water into the jacket 6 to further reduce the temperature and pressure of the polymerization kettle 1, and releases part of the pressure through the emergency vent pipeline 3, so that the temperature or pressure of the polymerization kettle 1 drops below the upper limit to ensure that the production is in a safe state.

[0024] Example 2

[0025] On the basis of Example 1, Figure 1 As shown, the polymerization kettle 1 is provided with a second temperature sensor 13 and a second pressure sensor 14, the tetrafluoroethylene feed pipeline 2 is provided with a second tetrafluoroethylene feed valve 202, the emergency venting pipeline 3 is provided with a second emergency venting valve 302, the steam feed pipeline 7 is provided with a second steam feed valve 702, the condensed water outlet pipeline 8 is provided with a second condensed water outlet valve 802, the chilled water inlet pipeline 9 is provided with a second chilled water inlet valve 902, and the chilled water outlet pipeline 10 is provided with a second chilled water outlet valve 1002; the second temperature sensor 13, the second pressure sensor 14, the second tetrafluoroethylene feed valve 202, the second emergency venting valve 302, the motor 5, the second steam feed valve 702, the second condensed water outlet valve 802, the second chilled water inlet valve 902 and the second chilled water outlet valve 1002 are electrically connected to the safety instrument system respectively.

[0026] Working principle:

[0027] The high limit and high-high limit of the temperature and pressure of the polymerization kettle 1 are preset in the SIS system, and the high limit is greater than the high-high limit preset in the DCS system. During the reaction, the second temperature sensor 13 and the second pressure sensor 14 provide real-time feedback of the temperature or pressure information of the polymerization kettle 1 to the SIS system. When over-temperature and over-pressure occur, if the DCS system does not act, so that the temperature and pressure of the polymerization kettle 1 continue to rise, then when the second temperature sensor 13 or the second pressure sensor 14 detects that the reaction temperature or pressure of the polymerization kettle 1 reaches the upper limit, the SIS system issues a high limit alarm to remind the staff; when the temperature and pressure of the polymerization kettle 1 continue to rise, and the second temperature sensor 13 or the second pressure sensor 14 detects that the reaction temperature or pressure of the polymerization kettle 1 reaches the upper limit, the SIS system controls the closing of the second tetrafluoroethylene feed valve 202, the second steam feed valve 702 and the second condensate outlet valve 802, stops feeding and stops passing steam, and closes the motor 5 to stop stirring, and at the same time opens the second chilled water inlet valve 902, the second chilled water outlet valve 1002 and the second emergency vent valve 302, passes chilled water into the jacket 6 to further reduce the temperature and pressure of the polymerization kettle 1, and releases part of the pressure through the emergency vent pipeline 3, so that the temperature or pressure of the polymerization kettle 1 drops below the upper limit, ensuring that the production is in a safe state.

Claims

1. The safety interlock system of the polytetrafluoroethylene polymerization kettle produced by the suspension process is characterized by: The polymerization kettle (1) is connected to a tetrafluoroethylene feed pipeline (2) and an emergency venting pipeline (3), the tetrafluoroethylene feed pipeline (2) is provided with a first tetrafluoroethylene feed valve (201), and the emergency venting pipeline (3) is provided with a first emergency venting valve (301); the polymerization kettle (1) is provided with a stirrer (4), and the stirrer (4) is driven by a motor (5); a jacket (6) is provided outside the polymerization kettle (1), and the jacket (6) is connected to a steam feed pipeline (7), a condensed water outlet pipeline (8), a chilled water inlet pipeline (9) and a chilled water outlet pipeline (10), the steam feed pipeline (7) is provided with a first steam feed valve (701), and the condensed water outlet pipeline (8) is provided with a first A condensed water outlet valve (801), a first chilled water inlet valve (901) is arranged on the chilled water inlet pipeline (9), and a first chilled water outlet valve (1001) is arranged on the chilled water outlet pipeline (10); the polymerization kettle (1) is provided with a first temperature sensor (11) and a first pressure sensor (12), and the first temperature sensor (11), the first pressure sensor (12), the first tetrafluoroethylene feed valve (201), the first emergency vent valve (301), the motor (5), the first steam feed valve (701), the first condensed water outlet valve (801), the first chilled water inlet valve (901) and the first chilled water outlet valve (1001) are respectively electrically connected to the distributed instrument control system.

2. The safety interlock system for the polytetrafluoroethylene polymerization reactor produced by the suspension process as claimed in claim 1, characterized in that: The polymerization kettle (1) is provided with a second temperature sensor (13) and a second pressure sensor (14); the tetrafluoroethylene feed line (2) is provided with a second tetrafluoroethylene feed valve (202); the emergency vent line (3) is provided with a second emergency vent valve (302); the steam feed line (7) is provided with a second steam feed valve (702); the condensate outlet line (8) is provided with a second condensate outlet valve (802); the chilled water inlet line (9) is provided with a second chilled water inlet valve (803); and the second tetrafluoroethylene feed line (202) is provided with a second tetrafluoroethylene feed valve (202). A water valve (902), a second chilled water outlet valve (1002) is arranged on the chilled water outlet pipeline (10); a second temperature sensor (13), a second pressure sensor (14), a second tetrafluoroethylene feed valve (202), a second emergency vent valve (302), a motor (5), a second steam feed valve (702), a second condensate outlet valve (802), a second chilled water inlet valve (902) and the second chilled water outlet valve (1002) are respectively electrically connected to the safety instrument system.

3. The safety interlock system for the polytetrafluoroethylene polymerization reactor produced by the suspension process as claimed in claim 1, characterized in that: The tetrafluoroethylene feed pipeline (2) and the emergency vent pipeline (3) are connected to the top of the polymerization kettle (1).

4. The safety interlock system for the polytetrafluoroethylene polymerization reactor produced by the suspension process as claimed in claim 1, characterized in that: The steam feed line (7) is connected to the upper part of the jacket (6).

5. The safety interlock system for the polytetrafluoroethylene polymerization reactor produced by the suspension process as claimed in claim 4, characterized in that: The condensate outlet pipeline (8) is connected to the lower part of the jacket (6).

6. The safety interlock system for the polytetrafluoroethylene polymerization reactor produced by the suspension process as claimed in claim 1, characterized in that: The chilled water inlet pipeline (9) is connected to the lower part of the jacket (6).

7. The safety interlock system for the polytetrafluoroethylene polymerization reactor produced by the suspension process as claimed in claim 6, characterized in that: The chilled water outlet pipeline (10) is connected to the upper part of the jacket (6).

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