Gas mixing system for acrylic acid production

Abstract

The utility model relates to the technical field of acrylic acid production equipment, in particular to a gas mixing system for acrylic acid production. The device comprises a gas storage tank arranged at the central position, one side of the gas storage tank is communicated with a mixed gas inlet pipeline, and the other side of the gas storage tank is communicated with a mixed gas outlet pipeline. A gas mixer is communicated outside the gas storage tank on the gas inlet pipeline, the gas mixer is communicated with the gas storage tank through a mixed gas inlet valve, and nitrogen and air enter the gas storage tank to be stored through the mixed gas inlet valve after passing through the gas mixer; according to the utility model, nitrogen with lower oxygen content can be continuously introduced as protective gas, so that the requirements of activation of polymerization inhibitors in the storage and production processes of acrylic acid and monomers thereof are met, and meanwhile, the oxygen content is controlled not to be too high to cause potential safety hazards.

Description

Technical Field

[0001] The utility model relates to the technical field of acrylic acid production equipment, in particular to a gas mixing system for acrylic acid production. Background Art

[0002] Acrylic acid and its monomers are needed in the chemical production process. Since they contain acrylic acid carbon-carbon double bonds, they are unstable and prone to polymerization reactions. This can affect the quality of the raw materials and thus the product quality at the very least. In severe cases, the polymerization of the double bonds of acrylic acid and its monomers will release a large amount of heat. If the heat cannot be removed, it will cause major safety accidents.

[0003] In order to solve the problem of easy polymerization of acrylic acid and its monomers, MEHQ is generally added as a polymerization inhibitor during storage and use. For example, a Chinese patent with publication number CN117887035A discloses a method for producing polyurethane acrylate, which includes the following steps: S1, first add polyester polyol into a reactor; then add a mixture of catalyst tetraethylammonium chloride, polymerization inhibitor BHT and polymerization inhibitor MEHQ into the reactor; S2, first heat the reactor to 70 to 80°, then drop IPDI into the reactor, and finally drop hydroxyethyl acrylate into the reactor for end-capping; S3, keep the reactor temperature at 80°±5°, keep the reactor pressure at standard atmospheric pressure, and control the reaction time to 8h to 10h; S4, after the reaction is completed, add diluent trimethylolpropane triacrylate into the reactor.

[0004] MEHQ needs oxygen activation to work better, so oxygen (usually air) needs to be added to the system using acrylic acid and its monomers to activate the inhibitor MEHQ. However, chemical production systems often contain flammable and explosive substances. When the oxygen content is too high, an explosive gas environment is likely to be generated, which can easily cause fires or even explosions if not properly controlled.

[0005] To solve the above problems, nitrogen with a low oxygen content (generally 5%) needs to be introduced as a protective gas into the place where acrylic acid and its monomers are used. The general practice is to manually adjust the air intake according to the flow meter or to adjust the ratio of the two according to the air and nitrogen flow meters to achieve this purpose.

[0006] In order to solve the above problems, the utility model provides a gas mixing system for acrylic acid production. Utility Model Content

[0007] The utility model aims to provide a gas mixing system for acrylic acid production to solve the problems raised in the above background technology.

[0008] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0009] A gas mixing system for acrylic acid production includes a gas storage tank, an air pipeline and a nitrogen pipeline are arranged outside the gas storage tank, the air pipeline and the nitrogen pipeline are mixed by a gas mixer and then introduced into the gas storage tank, and the two pipelines are respectively provided with

[0010] An air control assembly is provided on the air pipeline and is used to adjust the air intake in the air pipeline;

[0011] A nitrogen control component is provided on the nitrogen pipeline and is used to adjust the nitrogen intake in the nitrogen pipeline;

[0012] The gas storage tank is connected with an outlet pipeline, which includes an outlet for discharging the mixed gas and a vent for discharging unqualified gas; an outlet assembly is arranged on the outlet pipeline to control and select the outlet position of the mixed gas;

[0013] The air control components, nitrogen control components and gas outlet components are all controlled by the DCS control system or PLC control system.

[0014] More optimally, the air control assembly includes a pipeline connected to the gas mixer, and an air intake manual valve, an air pressure reducing valve, and an air flow meter that are sequentially connected to the pipeline.

[0015] More optimally, the nitrogen control assembly includes a pipeline connected to the gas mixer, and a nitrogen inlet manual valve, a nitrogen pressure reducing valve, a nitrogen flow meter and a nitrogen regulating valve which are sequentially connected to the pipeline.

[0016] More optimally, a mixed air inlet valve is connected between the gas mixer and the air storage tank, and a mixed air outlet valve is connected between the air storage tank and the air outlet pipeline.

[0017] More optimally, the gas outlet pipeline includes a pipeline and a mixed gas flow meter arranged on the pipeline, and an outlet ball valve and an outlet valve are arranged between the mixed gas flow meter and the gas outlet.

[0018] More optimally, a vent ball valve and a vent valve are provided between the mixed gas flow meter and the vent port.

[0019] More optimally, the pipeline of the gas outlet is connected to an oxygen analysis instrument and is provided with an instrument manual valve for controlling the gas flux.

[0020] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0021] (1) In the utility model, the nitrogen and air can be mixed automatically to ensure that the oxygen content and nitrogen content of the output protective gas meet the requirements.

[0022] (2) In the present invention, through the cooperation of the two pipelines, the two gases can be stably transported for mixing, and evenly mixed in the gas mixer and stored in the gas storage tank, thereby ensuring that the quality and delivery volume of the mixed gas meet the standards.

[0023] (3) In the present invention, an air outlet and an exhaust port are provided, so that when the mixed gas does not meet the requirements, the gas can be discharged through the exhaust port to prevent the substandard gas from entering the next unit.

[0024] (4) In the present invention, an oxygen analyzer is provided to monitor the composition status of the mixed gas in real time to ensure that the gas output meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of the process of the utility model.

[0027] Among them, V1, air inlet manual valve; V2, nitrogen inlet manual valve; PCV1, air pressure reducing valve; PCV2, nitrogen pressure reducing valve; FL1, air flow meter; FL2, nitrogen flow meter; FV1, nitrogen regulating valve; V3, mixed air inlet valve; V4, mixed air outlet valve; V5, instrument manual valve; AT, oxygen analyzer; FL3, mixed gas flow meter; XV1, outlet ball valve; V7, outlet manual valve; XV2, vent ball valve; V6, vent manual valve; 8, gas mixer; 9, gas storage tank; 10, air pipeline; 11, nitrogen pipeline; 12, outlet pipeline; 121, outlet; 122, vent. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] A gas mixing system for acrylic acid production, mainly used for mixing nitrogen and air, such as Figure 1As shown, it includes a gas storage tank 9 located at the most central position, one side of the gas storage tank 9 is connected to the mixed gas inlet pipeline, and the other side is connected to the mixed gas outlet pipeline. On the inlet pipeline, the gas storage tank 9 is connected to a gas mixer 8, and the gas mixer 8 is connected to the gas storage tank 9 through a mixed inlet valve V3. After passing through the gas mixer 8, nitrogen and air enter the gas storage tank 9 through the mixed inlet valve V3 for storage.

[0030] In order to ensure smooth mixing of nitrogen and air, two pipelines are connected to the gas mixer 8 , one is an air pipeline 10 for conveying air into the gas mixer 8 ; the other is a nitrogen pipeline 11 for conveying nitrogen into the gas mixer 8 .

[0031] The air pipeline 10 is connected to an external air source. An air intake manual valve V1, an air pressure reducing valve PCV1 and an air flow meter FL1 are arranged in sequence on the air pipeline 10. The air passes through the air intake manual valve V1, the air pressure reducing valve PCV1 and the air flow meter FL1 in sequence and then enters the gas mixer 8.

[0032] The nitrogen pipeline 11 is connected to the external nitrogen source. A nitrogen inlet manual valve V2, a nitrogen pressure reducing valve PCV2, a nitrogen flow meter FL2 and a nitrogen regulating valve FV1 are arranged in sequence on the nitrogen pipeline 11. After passing through the nitrogen inlet manual valve V2, the nitrogen pressure reducing valve PCV2, the nitrogen flow meter FL2 and the nitrogen regulating valve FV1, the nitrogen is transported to the gas mixer 8 and mixed with the air to form a mixed gas.

[0033] The gas outlet pipeline connected to the gas storage tank 9 is provided with a mixed gas outlet valve V4 and a mixed gas flow meter FL3, which are used to control the output of the mixed gas from the gas storage tank 9. At the same time, the gas outlet pipeline is provided with two outlets, namely, an outlet 121 and a vent 122. At the beginning of gas mixing, when the mixed gas does not meet the standard, the mixed gas can be discharged from the vent 122; when the mixed gas meets the standard, it is transported to the next unit through the outlet 121.

[0034] On the pipeline of the gas outlet 121, an outlet ball valve XV1 is provided between the mixed gas flow meter FL3 and the gas outlet 121; a vent ball valve XV2 and a vent hand valve V6 are provided between the mixed gas flow meter FL3 and the vent 122, so as to control the exhaust volume of the mixed gas at the gas outlet 121 and the vent 122.

[0035] In addition, the pipeline of the gas outlet 121 is also connected to an oxygen analyzer AT, and is provided with an instrument manual valve V5 for controlling the gas flux. The air control component, nitrogen control component and gas outlet component are all controlled by a DCS control system or a PLC control system, thereby improving the automation level of the entire system.

[0036] In order to meet the requirements of inhibitor activation during the storage and production of acrylic acid and its monomers, and to control the oxygen content so as not to cause safety hazards, it is necessary to introduce nitrogen with a lower oxygen content (generally 5%) as a protective gas. When the utility model introduces 5% nitrogen in the mixture, the specific operation process is as follows:

[0037] 1. Open the nitrogen inlet manual valve V2 and adjust the nitrogen pressure to 0.4Mpa through the nitrogen pressure reducing valve PCV2;

[0038] 2. Open the air inlet hand valve V1, and adjust the air pressure to 0.5Mpa through the air pressure reducing valve PCV1. When preparing the mixed gas, the air pressure must be 0.1-0.2Mpa higher than the nitrogen pressure;

[0039] 3. Set the required oxygen content ratio of 5% on the DCS or PLC, click the start program button, and the proportioning system will enter the running state, automatically controlling the opening of the air pressure reducing valve PCV1 according to the state of the air flow meter FL1, and then controlling the nitrogen flow in the nitrogen flow meter FL2 to reach the required oxygen content;

[0040] 4. Nitrogen and air are fully mixed in the gas mixer 8 and enter the gas storage tank 9.

[0041] 5. Detect the oxygen concentration at the outlet of the gas storage tank 9. If the oxygen content ratio is unqualified during initial operation, the venting ball valve XV2 will be automatically opened to vent. After about 2-5 minutes, the oxygen content is qualified, the venting ball valve XV2 will be automatically closed, the outlet ball valve XV1 will automatically open, and the outlet hand valve V7 will be opened to output the gas, thereby achieving a stable supply of mixed gas.

[0042] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0043] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A gas mixing system for acrylic acid production, characterized in that: The invention comprises a gas storage tank (9), wherein an air pipeline (10) and a nitrogen pipeline (11) are arranged outside the gas storage tank (9), wherein the air pipeline (10) and the nitrogen pipeline (11) are mixed by a gas mixer (8) and then introduced into the gas storage tank (9), and the two pipelines are respectively provided with An air control component, disposed on the air pipeline (10) and used for adjusting the air intake in the air pipeline (10); A nitrogen control component, arranged on the nitrogen pipeline (11), and used for adjusting the nitrogen intake in the nitrogen pipeline (11); The gas storage tank (9) is connected to a gas outlet pipeline (12), and the gas outlet pipeline (12) comprises a gas outlet (121) for discharging the mixed gas, and a vent (122) for discharging unqualified gas; the gas outlet pipeline (12) is provided with a gas outlet component for controlling and selecting the outlet position of the mixed gas; The air control component, the nitrogen control component and the gas outlet component are all regulated by a DCS control system or a PLC control system.

2. A gas mixing system for acrylic acid production according to claim 1, characterized in that: The air control assembly comprises a pipeline connected to the gas mixer (8), and an air intake manual valve (V1), an air pressure reducing valve (PCV1), and an air flow meter (FL1) which are sequentially connected to the pipeline.

3. The gas mixing system for acrylic acid production according to claim 1, characterized in that: The nitrogen control assembly comprises a pipeline connected to the gas mixer (8), and a nitrogen inlet manual valve (V2), a nitrogen pressure reducing valve (PCV2), a nitrogen flow meter (FL2) and a nitrogen regulating valve (FV1) which are sequentially connected to the pipeline.

4. The gas mixing system for acrylic acid production according to claim 1, characterized in that: A mixed air inlet valve (V3) is connected between the gas mixer (8) and the gas storage tank (9), and a mixed air outlet valve (V4) is connected between the gas storage tank (9) and the gas outlet pipeline (12).

5. The gas mixing system for acrylic acid production according to claim 1, characterized in that: The gas outlet pipeline (12) comprises a pipeline and a mixed gas flow meter (FL3) arranged on the pipeline, and a gas outlet ball valve (XV1) and a gas outlet manual valve (V7) are arranged between the mixed gas flow meter (FL3) and the gas outlet (121).

6. A gas mixing system for acrylic acid production according to claim 5, characterized in that: A vent ball valve (XV2) and a vent hand valve (V6) are provided between the mixed gas flow meter (FL3) and the vent port (122).

7. A gas mixing system for acrylic acid production according to claim 5, characterized in that: The pipeline of the gas outlet (121) is connected to an oxygen analysis instrument (AT) and is provided with an instrument manual valve (V5) for controlling the gas flux.

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