Safety interlocking system of monochlorodifluoromethane fluorination reactor

Abstract

The utility model discloses a safety interlocking system of a monochlorodifluoromethane fluorination reactor, which is characterized in that the fluorination reactor is connected with a chloroform feeding pipeline, an anhydrous hydrogen fluoride feeding pipeline and a liquid chlorine feeding pipeline, the fluorination reactor is provided with a steam jacket, and the steam jacket is connected with a steam feeding pipeline and a condensate water outlet pipeline; the chloroform feeding pipeline is provided with a first chloroform feeding valve, the anhydrous hydrogen fluoride feeding pipeline is provided with a first anhydrous hydrogen fluoride feeding valve, and the steam feeding pipeline is provided with a first steam feeding valve; the fluorination reactor is provided with a temperature sensor and a first pressure sensor, and the first chloroform feed valve, the first anhydrous hydrogen fluoride feed valve, the first steam feed valve, the temperature sensor and the first pressure sensor are electrically connected with a dispersion instrument control system. According to the utility model, the first chloroform feed valve, the first anhydrous hydrogen fluoride feed valve and the first steam feed valve can be controlled to be closed when overtemperature and overpressure occur in the fluorination reactor, 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 difluoromonochloromethane production, in particular to a safety interlocking system of a difluoromonochloromethane fluorination reactor. Background Art

[0002] There are two main processes for producing chlorodifluoromethane: 1) Direct method: direct synthesis of methane, chlorine and anhydrous hydrogen fluoride in a fluidized bed reactor; 2) Indirect method: in the presence of antimony pentachloride catalyst, anhydrous hydrogen fluoride and chloroform interact to produce it. Among them, the indirect method is characterized by low production cost and short process flow.

[0003] In the indirect process of producing difluorochloromethane, the raw materials chloroform (chloroform) and anhydrous hydrogen fluoride (AHF) undergo fluorination reaction under the action of a catalyst, and the reaction equation is: CHCl2F+HF→CHClF2+HCl. Liquid phase reaction is adopted, HCl is separated by dry method, and then the finished difluorochloromethane is obtained through liquid phase water washing, alkali washing, distillation and other processes.

[0004] The fluorination reaction is particularly critical in the production process of chlorodifluoromethane. The liquid chlorine and anhydrous hydrogen fluoride involved in the fluorination reactor are highly toxic substances, and the reaction process is an endothermic reaction. If an over-temperature and over-pressure accident occurs in the fluorination reactor, it will cause material leakage or even poisoning 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 chlorodifluoromethane fluorination reactor to ensure the safe production. Utility Model Content

[0005] The technical problem to be solved by the utility model is: to overcome the deficiencies of the prior art and provide a safety interlock system for a difluoromonochloromethane fluorination reactor, which, through a distributed instrument control system, controls the closing of a first chloroform feed valve, a first anhydrous hydrogen fluoride feed valve and a first steam feed valve when overtemperature and overpressure occur in the fluorination reactor, stops feeding and stops introducing steam, thereby ensuring that production is in a safe state.

[0006] The technical solution of the utility model is:

[0007] A safety interlock system for a fluorination reactor of chlorodifluoromethane, wherein the fluorination reactor is connected with a chloroform feed pipeline, an anhydrous hydrogen fluoride feed pipeline and a liquid chlorine feed pipeline, a steam jacket is arranged outside the fluorination reactor, and the steam jacket is connected with a steam feed pipeline and a condensed water outlet pipeline; a first chloroform feed valve is arranged on the chloroform feed pipeline, a first anhydrous hydrogen fluoride feed valve is arranged on the anhydrous hydrogen fluoride feed pipeline, and a first steam feed valve is arranged on the steam feed pipeline; a temperature sensor and a first pressure sensor are arranged on the fluorination reactor, and the first chloroform feed valve, the first anhydrous hydrogen fluoride feed valve, the first steam feed valve, the temperature sensor and the first pressure sensor are electrically connected to a distributed instrument control system, respectively.

[0008] Preferably, a liquid chlorine feed valve is provided on the liquid chlorine feed pipeline, a second chloroform feed valve is provided on the chloroform feed pipeline, a second anhydrous hydrogen fluoride feed valve is provided on the anhydrous hydrogen fluoride feed pipeline, and a second steam feed valve is provided on the steam feed pipeline; a second pressure sensor is provided on the fluorination reactor, and the liquid chlorine feed valve, the second chloroform feed valve, the second anhydrous hydrogen fluoride feed valve, the second steam feed valve and the second pressure sensor are electrically connected to the safety instrument system, respectively.

[0009] Preferably, the fluorination reactor is connected to an emergency vent pipeline, the emergency vent pipeline is provided with an emergency vent valve, and the emergency vent valve is electrically connected to the safety instrument system.

[0010] Preferably, the emergency vent line is connected to the top of the fluorination reactor.

[0011] Preferably, the steam jacket is connected to a circulating water inlet pipeline and a circulating water outlet pipeline, the circulating water inlet pipeline is provided with a circulating water inlet valve, and the circulating water inlet valve is electrically connected to the safety instrument system.

[0012] Preferably, the chloroform feed line, the anhydrous hydrogen fluoride feed line and the liquid chlorine feed line are all connected to the top of the fluorination reactor.

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

[0014] The utility model uses a distributed instrument control system to stop feeding and steam introduction by controlling the closing of the first chloroform feed valve, the first anhydrous hydrogen fluoride feed valve and the first steam feed valve when the fluorination reactor is over-temperature and over-pressure, thereby ensuring that the production is in a safe state. In addition, when an over-temperature and over-pressure accident occurs and the distributed instrument control system does not operate, the liquid chlorine feed valve, the second chloroform feed valve, the second anhydrous hydrogen fluoride feed valve, the second steam feed valve, the emergency vent valve and the circulating water inlet valve can be controlled by the safety instrument system to stop feeding and steam introduction; at the same time, a part of the pressure is released, and the temperature and pressure of the fluorination reactor are further reduced by circulating water, thereby ensuring that the production is in a safe state. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The utility model is a schematic diagram of the structure of the safety interlock system of the difluoromonochloromethane fluorination reactor.

[0016] In the figure, 1, fluorination reactor; 2, chloroform feed pipeline; 201, first chloroform feed valve; 202, second chloroform feed valve; 3, anhydrous hydrogen fluoride feed pipeline; 301, first anhydrous hydrogen fluoride feed valve; 302, second anhydrous hydrogen fluoride feed valve; 4, liquid chlorine feed pipeline; 401, liquid chlorine feed valve; 5, steam jacket; 6, steam feed pipeline; 601, first steam feed valve; 602, second steam feed valve; 7, condensate outlet pipeline; 8, temperature sensor; 9, first pressure sensor; 10, second pressure sensor; 11, emergency vent pipeline; 1101, emergency vent valve; 12, circulating water inlet pipeline; 1201, circulating water inlet valve; 13, circulating water outlet pipeline. DETAILED DESCRIPTION

[0017] 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.

[0018] Example 1

[0019] like Figure 1 As shown, this embodiment provides a safety interlock system for a difluoromonochloromethane fluorination reactor, wherein a chloroform feed pipeline 2, an anhydrous hydrogen fluoride feed pipeline 3 and a liquid chlorine feed pipeline 4 are connected to the top of the fluorination reactor 1, a steam jacket 5 is arranged outside the fluorination reactor 1, and a steam feed pipeline 6 and a condensed water outlet pipeline 7 are connected to the steam jacket 5; a first chloroform feed valve 201 is arranged on the chloroform feed pipeline 2, a first anhydrous hydrogen fluoride feed valve 301 is arranged on the anhydrous hydrogen fluoride feed pipeline 3, and a first steam feed valve 601 is arranged on the steam feed pipeline 6; a temperature sensor 8 and a first pressure sensor 9 are arranged on the fluorination reactor 1, and the first chloroform feed valve 201, the first anhydrous hydrogen fluoride feed valve 301, the first steam feed valve 601, the temperature sensor 8 and the first pressure sensor 9 are electrically connected to a distributed instrument control (DCS) system, respectively.

[0020] Working principle:

[0021] The high limit and high-high limit of the temperature and pressure of the fluorination reactor 1 are preset in the DCS system. During the reaction process, the temperature sensor 8 and the first pressure sensor 9 respectively feed back the temperature and pressure information of the fluorination reactor 1 to the DCS system in real time. When the temperature sensor 8 or the first pressure sensor 9 detects that the reaction temperature or pressure of the fluorination reactor 1 reaches the high limit, the DCS system issues a high limit alarm to remind the staff; when the temperature sensor 8 or the first pressure sensor 9 detects that the reaction temperature or pressure of the fluorination reactor 1 reaches the high-high limit, the DCS system controls the closing of the first chloroform feed valve 201, the first anhydrous hydrogen fluoride feed valve 301 and the first steam feed valve 601, stops feeding and stops passing steam into the steam jacket 5, so that the temperature or pressure of the fluorination reactor 1 drops below the high limit to ensure that the production is in a safe state.

[0022] Example 2

[0023] On the basis of Example 1, Figure 1 As shown, the top of the fluorination reactor 1 is also connected to an emergency venting pipeline 11, and an emergency venting valve 1101 is provided on the emergency venting pipeline 11; the steam jacket 5 is connected to a circulating water inlet pipeline 12 and a circulating water outlet pipeline 13, and a circulating water inlet valve 1201 is provided on the circulating water inlet pipeline 12; a liquid chlorine feed valve 401 is provided on the liquid chlorine feed pipeline 4, a second chloroform feed valve 202 is provided on the chloroform feed pipeline 2, and a hydrogen fluoride feed valve 203 is provided on the anhydrous hydrogen fluoride feed pipeline 3. A second anhydrous hydrogen fluoride feed valve 302 is provided, and a second steam feed valve 602 is provided on the steam feed pipeline 6; a second pressure sensor 10 is provided on the fluorination reactor 1, and the emergency vent valve 1101, the circulating water inlet valve 1201, the liquid chlorine feed valve 401, the second chloroform feed valve 202, the second anhydrous hydrogen fluoride feed valve 302, the second steam feed valve 602 and the second pressure sensor 10 are respectively electrically connected to the safety instrument (SIS) system.

[0024] Working principle:

[0025] The pressure upper limit and high-high limit of the fluorination reactor 1 are preset in the SIS system. The pressure upper limit is greater than the pressure upper-high limit preset in the DCS system. During the reaction, the second pressure sensor 10 feeds back the pressure information of the fluorination reactor 1 to the SIS system in real time. When over-temperature and over-pressure occur, if the DCS system does not act, so that the pressure of the fluorination reactor 1 continues to rise, then when the second pressure sensor 10 detects that the reaction pressure of the fluorination reactor 1 reaches the upper limit, the SIS system issues a high limit alarm to remind the staff; when the pressure of the fluorination reactor 1 continues to rise, and the second pressure sensor 10 detects that the reaction pressure of the fluorination reactor 1 reaches the upper limit, the SIS system controls the closure of the liquid chlorine feed valve 401, the second chloroform feed valve 202, the second anhydrous hydrogen fluoride feed valve 302 and the second steam feed valve 602, stops feeding and stops passing steam into the steam jacket 5; at the same time, the SIS system controls the opening of the emergency vent valve 1101 and the circulating water inlet valve 1201, while releasing part of the pressure, the circulating water passed into the steam jacket 5 further reduces the temperature of the fluorination reactor 1, and then reduces the pressure, so that the pressure of the fluorination reactor 1 drops below the upper limit, ensuring that the production is in a safe state.

Claims

1. A safety interlock system for a fluorination reactor of difluoromonochloromethane, characterized in that: The fluorination reactor (1) is connected to a chloroform feed pipeline (2), an anhydrous hydrogen fluoride feed pipeline (3) and a liquid chlorine feed pipeline (4); a steam jacket (5) is arranged outside the fluorination reactor (1); a steam feed pipeline (6) and a condensed water outlet pipeline (7) are connected to the steam jacket (5); a first chloroform feed valve (201) is arranged on the chloroform feed pipeline (2), a first anhydrous hydrogen fluoride feed valve (301) is arranged on the anhydrous hydrogen fluoride feed pipeline (3), and a first steam feed valve (601) is arranged on the steam feed pipeline (6); a temperature sensor (8) and a first pressure sensor (9) are arranged on the fluorination reactor (1); the first chloroform feed valve (201), the first anhydrous hydrogen fluoride feed valve (301), the first steam feed valve (601), the temperature sensor (8) and the first pressure sensor (9) are respectively electrically connected to a distributed instrument control system.

2. The safety interlock system of the difluorochloromethane fluorination reactor according to claim 1, characterized in that: The liquid chlorine feed pipeline (4) is provided with a liquid chlorine feed valve (401), the chloroform feed pipeline (2) is provided with a second chloroform feed valve (202), the anhydrous hydrogen fluoride feed pipeline (3) is provided with a second anhydrous hydrogen fluoride feed valve (302), and the steam feed pipeline (6) is provided with a second steam feed valve (602); the fluorination reactor (1) is provided with a second pressure sensor (10), and the liquid chlorine feed valve (401), the second chloroform feed valve (202), the second anhydrous hydrogen fluoride feed valve (302), the second steam feed valve (602) and the second pressure sensor (10) are respectively electrically connected to the safety instrument system.

3. The safety interlock system of the difluorochloromethane fluorination reactor according to claim 2, characterized in that: The fluorination reactor (1) is connected to an emergency vent pipeline (11), and an emergency vent valve (1101) is arranged on the emergency vent pipeline (11), and the emergency vent valve (1101) is electrically connected to a safety instrument system.

4. The safety interlock system of the difluorochloromethane fluorination reactor according to claim 3, characterized in that: The emergency venting pipeline (11) is connected to the top of the fluorination reactor (1).

5. The safety interlock system of the difluorochloromethane fluorination reactor according to any one of claims 2 to 4, characterized in that: The steam jacket (5) is connected to a circulating water inlet pipeline (12) and a circulating water outlet pipeline (13); a circulating water inlet valve (1201) is provided on the circulating water inlet pipeline (12); and the circulating water inlet valve (1201) is electrically connected to a safety instrument system.

6. The safety interlock system of the difluorochloromethane fluorination reactor according to claim 1, characterized in that: The chloroform feed pipeline (2), the anhydrous hydrogen fluoride feed pipeline (3) and the liquid chlorine feed pipeline (4) are all connected to the top of the fluorination reactor (1).

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