A redundant nitrogen conveying system applied to the production of methomyl

Abstract

The application relates to the chemical technology field and discloses a redundant nitrogen gas conveying system applied to methomyl production. In the application, a key user private line is arranged, and the first buffer tank and the second buffer tank jointly supply gas, when any gas source fails, the healthy gas source can immediately undertake the whole gas supply task through the private line, and the key user cannot fully perceive the switching process. The design of the key user private line provides an independent nitrogen gas supply channel which is preferentially guaranteed by a physical structure for a core production device, and ensures the safety of the key equipment under extreme working conditions. The pressure fluctuation risk window is fundamentally eliminated, and the safety risk is further reduced. The pipe network design of the double-path parallel connection is matched with an interconnection isolation valve, so that the system can isolate and maintain any path without stopping the whole nitrogen gas supply, and the usability and maintenance convenience of the system are greatly improved.

Description

Technical Field

[0001] This application relates to the field of chemical technology, specifically to a redundant nitrogen delivery system for methomyl production. Background Technology

[0002] In the production of highly hazardous chemicals such as methomyl, the nitrogen supply system is a critical facility for ensuring safety. Existing nitrogen supply systems typically employ a main nitrogen generator connected in series with a backup liquid nitrogen source, or a simple parallel connection. This architecture has significant drawbacks. When the main gas source fails and switching to the backup source is necessary, the valve switching and pipeline replacement processes cause a brief pressure drop in the pipeline network. This pressure fluctuation poses a safety hazard to critical reaction equipment requiring continuous and stable inerting protection. Furthermore, existing systems usually use a single ring or branched pipeline network; if a leak occurs anywhere in the network or maintenance is required, the nitrogen supply to the entire plant will be interrupted, severely impacting production continuity. Utility Model Content

[0003] In view of the above problems, this application provides a redundant nitrogen delivery system for methomyl production, which can achieve seamless switching, has higher reliability, and can provide absolute safety guarantee for core production equipment.

[0004] According to one aspect of the embodiments of this application, a redundant nitrogen delivery system for methomyl production is provided. The redundant nitrogen delivery system used in methomyl production includes a gas source unit, a buffer storage unit, and a distribution network unit. The gas source unit includes a main nitrogen-generating pipeline and a backup liquid nitrogen pipeline connected in parallel. The buffer storage unit includes a first buffer tank and a second buffer tank. The output end of the main nitrogen-generating pipeline is connected to the inlet of the first buffer tank, and the output end of the backup liquid nitrogen pipeline is connected to the inlet of the second buffer tank. The distribution network unit includes a first network and a second network that are independent of each other. The outlet of the first buffer tank is connected to the first network, and the outlet of the second buffer tank is connected to the second network. A normally closed interconnection isolation valve is installed between the first network and the second network. The outlets of the first and second buffer tanks are also connected to a dedicated critical user line for directly supplying gas to critical user equipment. A first check valve is installed on the connecting pipeline between the first buffer tank and the dedicated critical user line; a second check valve is installed on the connecting pipeline between the second buffer tank and the dedicated critical user line.

[0005] In some embodiments, an emergency backup unit is also included, which is a factory instrument air system. The factory instrument air system is connected to the air inlet of the first buffer tank through a pipe with a third check valve, and / or connected to the air inlet of the second buffer tank through a pipe with a check valve.

[0006] In some embodiments, a switching valve and a pressure regulating valve are sequentially arranged along the gas flow direction on the main nitrogen pipeline; a switching valve, a vaporizer, and a pressure regulating valve are sequentially arranged along the gas flow direction on the backup liquid nitrogen pipeline.

[0007] In some embodiments, the critical user dedicated line is equipped with a switching valve and a precision pressure regulating valve.

[0008] In some embodiments, pressure monitors and oxygen content analyzers are installed on the first pipeline and / or the second pipeline.

[0009] In some embodiments, the critical user equipment is a synthesis reactor or a methanethiol storage tank in the methomyl production process.

[0010] The beneficial effects of this application are: 1. This application establishes a dedicated gas supply line for critical users, with both a first buffer tank and a second buffer tank providing gas. In the event of a failure in either gas source, the healthy gas source can immediately assume the entire gas supply task through this dedicated line. The critical user is completely unaware of the switching process. This dedicated line design provides core production units with an independent nitrogen supply channel prioritized by their physical structure, ensuring the safety of critical equipment under extreme operating conditions. It fundamentally eliminates the pressure fluctuation risk window, further reducing safety risks.

[0011] 2. By installing check valves on the connecting pipelines of the first and second buffer tanks and the dedicated lines of critical users, the possibility of nitrogen backflow from the healthy pipeline to the faulty pipeline is eliminated from the physical structure in a purely mechanical way, ensuring the uniqueness and reliability of the system's airflow direction.

[0012] 3. The dual-parallel pipeline design, combined with interconnected isolation valves, allows for the isolation and maintenance of any pipeline without interrupting the overall nitrogen supply, greatly improving system availability and ease of maintenance.

[0013] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0014] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the overall structure of a redundant nitrogen delivery system for methomyl production, provided in an embodiment of this application.

[0015] The reference numerals in the detailed embodiments are as follows: The redundant nitrogen delivery system 100 used in methomyl production includes a gas source unit 110, a main nitrogen production pipeline 111, a switching valve 111a, a pressure regulating valve 111b, a backup liquid nitrogen pipeline 112, a vaporizer 112a, a buffer gas storage unit 120, a first buffer tank 121, a second buffer tank 122, a first pipeline network 130, a second pipeline network 140, an interconnection isolation valve 150, a dedicated line for critical users 160, a first check valve 161, a second check valve 162, a factory instrument ventilation system 170, and a third check valve 171. Detailed Implementation

[0016] The embodiments of the technical solution of this application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and the foregoing description of the accompanying drawings are intended to cover non-exclusive inclusion.

[0017] For details, please refer to Figure 1 , Figure 1This is a schematic diagram of the overall structure of a redundant nitrogen delivery system for methomyl production provided in this application embodiment. The redundant nitrogen delivery system 100 for methomyl production includes a gas source unit 110, a buffer gas storage unit 120, and a distribution pipeline unit. The gas source unit 110 is responsible for continuously and reliably producing and supplying nitrogen that meets the requirements. The gas source unit 110 includes a main nitrogen production pipeline 111 and a backup liquid nitrogen pipeline 112 connected in parallel. The main nitrogen production pipeline 111 serves as the primary gas source under normal operating conditions; it draws gas from the environment through an air separation nitrogen generator (such as a pressure swing adsorption or membrane separation device) to produce high-purity nitrogen. Its function is to economically and efficiently meet the majority of nitrogen demand during the production process. The backup liquid nitrogen pipeline 112 serves as a safety redundancy gas source and consists of a liquid nitrogen storage tank and a vaporizer 112a. The buffer gas storage unit 120 includes a first buffer tank 121 and a second buffer tank 122, both of which are large pressure vessels. The output end of the main nitrogen supply line 111 is connected to the air inlet of the first buffer tank 121, and the output end of the backup liquid nitrogen supply line 112 is connected to the air inlet of the second buffer tank 122. The main nitrogen supply line 111 can replenish nitrogen to the first buffer tank 121, and the backup liquid nitrogen supply line 112 can replenish nitrogen to the second buffer tank 122. The distribution network unit includes two independent pipelines: a first pipeline 130 and a second pipeline 140. The outlet of the first buffer tank 121 is connected to the first pipeline 130, and the outlet of the second buffer tank 122 is connected to the second pipeline 140. Here, the first pipeline 130 and the second pipeline 140 supply nitrogen to different working areas within the plant. Under normal operating conditions, the first pipeline 130 and the second pipeline 140 are independent and not interconnected. A normally closed interconnection isolation valve 150 is installed between the first pipeline 130 and the second pipeline 140. The two ends of the interconnection isolation valve 150 are connected to the first pipeline 130 and the second pipeline 140, respectively. During normal operation, the interconnection isolation valve 150 is normally closed, isolating the two pipelines. The function of the interconnection isolation valve 150 is to provide a "maintenance backup" channel. When any buffer tank or its gas source fails, this valve can be opened, allowing the healthy gas source to simultaneously supply gas to both pipelines, ensuring uninterrupted production. The outlets of the first buffer tank 121 and the second buffer tank 122 are also connected to a dedicated critical user line 160 for directly supplying nitrogen to critical user equipment, which are the synthesis reactors or methanethiol storage tanks in the methomyl production process. The dedicated user line draws nitrogen directly from one or more buffer tanks, ensuring that the nitrogen supply to critical users enjoys the highest priority. Physically, this ensures that in the event of any pipeline failure, nitrogen can always provide the highest level of safety assurance to the core process unit with virtually no delay and minimal pressure fluctuations.A first check valve 161 is installed on the connecting pipeline between the first buffer tank 121 and the critical user dedicated line 160; a second check valve 162 is installed on the connecting pipeline between the second buffer tank 122 and the critical user dedicated line 160. The first check valve 161 and the second check valve 162 are installed between the buffer tanks and the critical user dedicated line 160. Their core function is to ensure unidirectional airflow and absolutely prevent nitrogen from flowing back from the high-pressure healthy pipeline to the pipeline with lower pressure due to a fault, thereby ensuring the accuracy of airflow distribution and the safety and reliability of the system.

[0018] In some embodiments, an emergency backup unit is also included. This emergency backup unit is a factory instrument ventilation system 170. The factory instrument ventilation system 170 is connected to the air inlet of the first buffer tank 121 via a pipe with a third check valve 171, and / or connected to the air inlet of the second buffer tank 122 via a pipe with a check valve. In this embodiment, the introduction of the factory instrument ventilation system 170 provides a final safety line based on differential pressure passive response, independent of electricity or control systems. This maintains positive system pressure under extreme fault conditions, prevents air backflow, and further enhances safety.

[0019] In some embodiments, a switching valve 111a and a pressure regulating valve 111b are sequentially arranged on the main nitrogen supply line 111 along the gas flow direction; a switching valve 111a, a vaporizer 112a, and a pressure regulating valve 111b are sequentially arranged on the standby liquid nitrogen supply line 112 along the gas flow direction.

[0020] In some embodiments, a switching valve 111a and a precision pressure regulating valve 111b are provided on the critical user dedicated line 160. In this embodiment, the switching valve 111a and the precision pressure regulating valve 111b enable precise on / off control and pressure regulation of nitrogen gas supplied to the critical user, ensuring that core equipment receives the highest quality and most stable nitrogen supply.

[0021] In some embodiments, pressure monitors and oxygen content analyzers are installed on the first pipeline 130 and / or the second pipeline 140. In this embodiment, the installation of the pressure monitors and oxygen content analyzers enables real-time monitoring and early warning of the pipeline status (pressure, purity).

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although the foregoing embodiments have provided a detailed description of this application, 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. These 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 application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A redundant nitrogen delivery system for methomyl production, characterized in that, It includes a gas source unit, a buffer gas storage unit, and a distribution pipeline network unit; The gas source unit includes a main nitrogen generation pipeline and a backup liquid nitrogen pipeline connected in parallel. The buffer gas storage unit includes a first buffer tank and a second buffer tank. The output end of the main nitrogen generation pipeline is connected to the air inlet of the first buffer tank, and the output end of the backup liquid nitrogen pipeline is connected to the air inlet of the second buffer tank. The distribution network unit includes a first pipeline and a second pipeline that are independent of each other. The outlet of the first buffer tank is connected to the first pipeline, and the outlet of the second buffer tank is connected to the second pipeline. A normally closed interconnection isolation valve is provided between the first pipeline and the second pipeline. The outlets of the first buffer tank and the second buffer tank are also connected to a dedicated line for critical users, which is used to directly supply gas to critical user equipment. A first check valve is installed on the connecting pipeline between the first buffer tank and the critical user dedicated line; a second check valve is installed on the connecting pipeline between the second buffer tank and the critical user dedicated line.

2. The redundant nitrogen delivery system for methomyl production according to claim 1, characterized in that, It also includes an emergency backup unit, which is a factory instrument air system. The factory instrument air system is connected to the air inlet of the first buffer tank through a pipe with a third check valve, and / or connected to the air inlet of the second buffer tank through a pipe with a check valve.

3. The redundant nitrogen delivery system for methomyl production according to claim 1, characterized in that, The main nitrogen pipeline is equipped with a switch valve and a pressure regulating valve in sequence along the gas flow direction; the backup liquid nitrogen pipeline is equipped with a switch valve, a vaporizer, and a pressure regulating valve in sequence along the gas flow direction.

4. The redundant nitrogen delivery system for methomyl production according to claim 1, characterized in that, The key user dedicated line is equipped with a switching valve and a precision pressure regulating valve.

5. The redundant nitrogen delivery system for methomyl production according to claim 1, characterized in that, Pressure monitors and oxygen content analyzers are installed on the first pipeline and / or the second pipeline.

6. The redundant nitrogen delivery system for methomyl production according to claim 1, characterized in that, The key user equipment is the synthesis reactor or methanethiol storage tank in the methomyl production process.

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