Gas sampling device of acrylic acid oxidation reactor

Abstract

The utility model relates to the technical field of gas sampling of acrylic acid oxidation reactors, in particular to a gas sampling device of an acrylic acid oxidation reactor. The gas sampling device of the acrylic acid oxidation reactor comprises a buffer impurity removal tank and an ice water cooler, a first-stage bubbling type gas collection bottle, a second-stage bubbling type gas collection bottle and a third-stage bubbling type gas collection bottle are arranged in the ice water cooler, the buffer impurity removal tank is connected with the first-stage bubbling type gas collection bottle through a gas mass flow controller, and the second-stage bubbling type gas collection bottle is connected with the third-stage bubbling type gas collection bottle through a gas mass flow controller. The first-stage bubbling type gas collecting bottle is connected with the third-stage bubbling type gas collecting bottle through the second-stage bubbling type gas collecting bottle, and the third-stage bubbling type gas collecting bottle is connected with the first-stage gas sampling bag through the gas flowmeter. And the gas flow meter is provided with a temperature display. The device has the characteristics of simple structure, convenience in operation, low cost, accurate analysis data, small influence of external environment and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of gas sampling of acrylic acid oxidation reactors, in particular to a gas sampling device of acrylic acid oxidation reactors. Background Art

[0002] Propylene and air are the main raw materials for producing acrylic acid. In the production process, acrolein is first oxidized and then acrylic acid is generated. The generated acrylic acid passes through a quenching absorption tower to become an acrylic acid (45-50wt%) aqueous solution, which is then sent to a refining system for purification. The acrylic acid aqueous solution is passed through an azeotropic tower to remove water to obtain crude acrylic acid, which is then passed through a light component removal tower and a distillation tower to obtain polymerization-grade acrylic acid.

[0003] The acrylic acid oxidation reactor is the core of the acrylic acid and ester unit. The reaction conditions of the oxidation reactor determine the acrylic acid production and the benefits of the unit. The accuracy of the analysis and monitoring of the oxidation reactor is directly related to the yield of acrylic acid, the conversion rate of propylene, and whether the unit can operate safely and stably. The existing sampling device is a direct sampling device, and the mixed gas phase taken out needs to be further separated and processed in the laboratory, which greatly improves the efficiency of subsequent work and affects the accuracy of the data. Utility Model Content

[0004] In view of the above deficiencies in the prior art, the purpose of the utility model is to provide a gas sampling device for an acrylic acid oxidation reactor. By setting a bubbling gas collecting bottle and an ice water cooler, acetaldehyde, acrolein, acetic acid, acrylic acid and other substances contained in the gas are absorbed, which greatly improves the subsequent detection process and improves the accuracy of the detection data; by setting a primary gas sampling bag, a secondary gas sampling bag and a tertiary gas sampling bag, different gases are recovered separately, while improving the sampling accuracy, avoiding pollution to the atmosphere; the device has the characteristics of simple structure, easy operation, low cost, accurate analysis data, and little influence by the external environment.

[0005] The utility model is realized by adopting the following technical solutions:

[0006] The gas sampling device of the acrylic acid oxidation reactor comprises a buffer impurity removal tank and an ice water cooler, wherein a primary bubbling gas collecting bottle, a secondary bubbling gas collecting bottle and a tertiary bubbling gas collecting bottle are arranged inside the ice water cooler, the buffer impurity removal tank is connected to the primary bubbling gas collecting bottle through a gas mass flow controller, the primary bubbling gas collecting bottle is connected to the tertiary bubbling gas collecting bottle through the secondary bubbling gas collecting bottle, and the tertiary bubbling gas collecting bottle is connected to the primary gas sampling bag through a gas flow meter. The gas flow meter is provided with a temperature display.

[0007] The buffer impurity removal tank is connected with a connecting pipeline, a connecting pipeline valve is arranged on the connecting pipeline, and a nitrogen bottle is connected to the connecting pipeline.

[0008] The ice water cooler is open at the top. The first-stage bubbling gas collecting bottle, the second-stage bubbling gas collecting bottle and the third-stage bubbling gas collecting bottle are placed on the ice water cooler, and part of the bottle body is immersed in ice water.

[0009] A further-stage bubbling gas collecting bottle pipeline is arranged between the gas mass flow controller and the first-stage bubbling gas collecting bottle, and the further-stage bubbling gas collecting bottle pipeline extends into the bottom of the first-stage bubbling gas collecting bottle.

[0010] A pipeline for entering the secondary bubbling gas collecting bottle is provided between the primary bubbling gas collecting bottle and the secondary bubbling gas collecting bottle. The pipeline for entering the secondary bubbling gas collecting bottle extends into the bottom of the secondary bubbling gas collecting bottle. The connection between the pipeline for entering the secondary bubbling gas collecting bottle and the primary bubbling gas collecting bottle is located at the bottle mouth.

[0011] A pipeline for entering the third-stage bubbling gas collecting bottle is provided between the second-stage bubbling gas collecting bottle and the third-stage bubbling gas collecting bottle. The pipeline for entering the third-stage bubbling gas collecting bottle extends into the bottom of the third-stage bubbling gas collecting bottle. The connection between the pipeline for entering the third-stage bubbling gas collecting bottle and the second-stage bubbling gas collecting bottle is located at the bottle mouth.

[0012] A gas flow meter inlet pipeline is arranged between the three-stage bubbling gas collecting bottle and the gas flow meter.

[0013] The gas flow meter is connected with a secondary gas sampling bag and a tertiary gas sampling bag.

[0014] Gas sampling during the oxidation process is divided into two parts: first, gas samples are taken with a gas sampling bag. The main analysis items are: oxygen, nitrogen, carbon monoxide, propylene, propane, and carbon dioxide. Second, deionized water is injected into a three-stage bubbling absorption bottle and the gas volume is measured with a dry flow meter for absorption sampling and analysis. The main detection items are acetaldehyde, acrolein, acetic acid, acrylic acid, and total acid.

[0015] The working principle of the utility model is:

[0016] First, make sure that the operating conditions are stable. Sampling and analysis are not allowed within one hour after the operating conditions are changed. Connect the sampling pipeline to the pipeline to be sampled, open the valve of the nitrogen bottle, purge the sampling device, and collect the purged gas phase into the primary gas sampling bag; measure the ambient temperature near the gas flow meter, open the connecting pipeline valve, start collecting gas through the 3-stage absorption bottle (the time is controlled at 20-25 minutes), control the flow rate of the gas flow meter to 1L / min, and count by the stopwatch when the gas flow meter starts to work. After 10 minutes, collect the gas into the secondary gas sampling bag behind the gas flow meter. Close the connecting pipeline valve when sampling 25L, and record the exact time; open the valve of the nitrogen bottle, purge the sampling device, and collect the purged gas phase into the tertiary gas sampling bag. Among them, the gas flow meter has a temperature display. The primary bubbling gas collecting bottle, the secondary bubbling gas collecting bottle, and the tertiary bubbling gas collecting bottle are placed on the ice water cooler, and part of the bottle body is immersed in ice water.

[0017] Compared with the prior art, the beneficial effects of the utility model are:

[0018] The utility model adopts the gas sampling device of acrylic acid oxidation reactor, and by setting a bubbling gas collecting bottle and an ice water cooler, acetaldehyde, acrolein, acetic acid, acrylic acid and other substances contained in the gas are absorbed, which greatly improves the subsequent detection process and the accuracy of the detection data; by setting a primary gas sampling bag, a secondary gas sampling bag and a tertiary gas sampling bag, different gases are respectively recovered, and while the sampling accuracy is improved, the pollution to the atmosphere is avoided; the utility model has the characteristics of simple structure, convenient operation, low cost, accurate analysis data, and little influence by the external environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the gas sampling device for acrylic acid oxidation reactor of the utility model;

[0020] In the figure: 1. Buffer impurity removal tank; 2. Gas mass flow controller; 3. First-stage bubbling gas collecting bottle; 4. Second-stage bubbling gas collecting bottle; 5. Third-stage bubbling gas collecting bottle; 6. Gas flow meter; 7. First-stage gas sampling bag; 8. Second-stage gas sampling bag; 9. Third-stage gas sampling bag; 10. Nitrogen bottle; 11. Connecting pipeline; 12. Pipeline into first-stage bubbling gas collecting bottle; 13. Pipeline into second-stage bubbling gas collecting bottle; 14. Pipeline into third-stage bubbling gas collecting bottle; 15. Pipeline into gas flow meter; 16. Ice water cooler; 17. Connecting pipeline valve. DETAILED DESCRIPTION

[0021] In order to make the purpose and technical solution of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings.

[0022] Example 1

[0023] like Figure 1 As shown, the gas sampling device of the acrylic acid oxidation reactor comprises a buffer impurity removal tank 1 and an ice water cooler 16. The ice water cooler 16 is provided with a primary bubbling gas collecting bottle 3, a secondary bubbling gas collecting bottle 4 and a tertiary bubbling gas collecting bottle 5. The buffer impurity removal tank 1 is connected to the primary bubbling gas collecting bottle 3 through a gas mass flow controller 2. The primary bubbling gas collecting bottle 3 is connected to the tertiary bubbling gas collecting bottle 5 through the secondary bubbling gas collecting bottle 4. The tertiary bubbling gas collecting bottle 5 is connected to the primary gas sampling bag 7 through a gas flow meter 6. The buffer impurity removal tank 1 is connected with a connecting pipe 11, and a connecting pipe valve 17 is provided on the connecting pipe 11. The connecting pipe 11 is connected with a nitrogen bottle 10. The ice water cooler 16 is open at the top. The primary bubbling gas collecting bottle 3, the secondary bubbling gas collecting bottle 4 and the tertiary bubbling gas collecting bottle 5 are placed on the ice water cooler 16, and 2 / 3 of the bottle body is immersed in ice water. A pipeline 12 for entering the first-stage bubbling gas collecting bottle is provided between the gas mass flow controller 2 and the first-stage bubbling gas collecting bottle 3, and the pipeline 12 for entering the first-stage bubbling gas collecting bottle extends into the bottom of the first-stage bubbling gas collecting bottle 3. A pipeline 13 for entering the second-stage bubbling gas collecting bottle is provided between the first-stage bubbling gas collecting bottle 3 and the second-stage bubbling gas collecting bottle 4, and the pipeline 13 for entering the second-stage bubbling gas collecting bottle extends into the bottom of the second-stage bubbling gas collecting bottle 4, and the connection between the pipeline 13 for entering the second-stage bubbling gas collecting bottle and the first-stage bubbling gas collecting bottle 3 is located at the bottle mouth. A pipeline 14 for entering the third-stage bubbling gas collecting bottle is provided between the second-stage bubbling gas collecting bottle 4 and the third-stage bubbling gas collecting bottle 5, and the pipeline 14 for entering the third-stage bubbling gas collecting bottle extends into the bottom of the third-stage bubbling gas collecting bottle 5, and the connection between the pipeline 14 for entering the third-stage bubbling gas collecting bottle and the second-stage bubbling gas collecting bottle 4 is located at the bottle mouth. A pipeline 15 for entering the gas flow meter is provided between the third-stage bubbling gas collecting bottle 5 and the gas flow meter 6. The gas flow meter 6 is connected to a secondary gas sampling bag 8 and a tertiary gas sampling bag 9 .

[0024] The above-mentioned acrylic acid oxidation reactor gas sampling device, when in operation, comprises the following steps:

[0025] (1) First, make sure that the operating conditions are stable. Sampling and analysis are not allowed within one hour of changing the operating conditions. Connect the sampling pipeline to the sampling pipeline through the connecting pipeline 11, open the valve of the nitrogen bottle 10, purge the sampling device, and collect the purged gas phase into the primary gas sampling bag 7; (2) Measure the ambient temperature near the gas flow meter 6, open the connecting pipeline valve 17, and start collecting gas through the 3rd-level absorption bottle (the time is controlled at 20-25 minutes). Control the flow rate of the gas flow meter to 1L / min. When the gas flow meter starts to work, start the stopwatch. After 10 minutes, collect the gas into the secondary gas sampling bag 8 behind the gas flow meter 6. When sampling 25L, close the connecting pipeline valve 17 and record the exact time; (3) Open the valve of the nitrogen bottle 10, purge the sampling device, and collect the purged gas phase into the tertiary gas sampling bag 9.

Claims

1. A gas sampling device for an acrylic acid oxidation reactor, characterized in that: The invention comprises a buffer impurity removal tank (1) and an ice water cooler (16). A first-stage bubbling gas collecting bottle (3), a second-stage bubbling gas collecting bottle (4) and a third-stage bubbling gas collecting bottle (5) are arranged inside the ice water cooler (16). The buffer impurity removal tank (1) is connected to the first-stage bubbling gas collecting bottle (3) via a gas mass flow controller (2). The first-stage bubbling gas collecting bottle (3) is connected to the third-stage bubbling gas collecting bottle (5) via the second-stage bubbling gas collecting bottle (4). The third-stage bubbling gas collecting bottle (5) is connected to the first-stage gas sampling bag (7) via a gas flow meter (6).

2. The acrylic acid oxidation reactor gas sampling device according to claim 1, characterized in that: The buffer impurity removal tank (1) is connected to a connecting pipe (11), a connecting pipe valve (17) is provided on the connecting pipe (11), and a nitrogen bottle (10) is connected to the connecting pipe (11).

3. The acrylic acid oxidation reactor gas sampling device according to claim 1, characterized in that: The ice water cooler (16) is open at the top.

4. The acrylic acid oxidation reactor gas sampling device according to claim 1, characterized in that: A further bubbling gas collecting bottle pipeline (12) is provided between the gas mass flow controller (2) and the first-stage bubbling gas collecting bottle (3), and the further bubbling gas collecting bottle pipeline (12) extends into the bottom of the first-stage bubbling gas collecting bottle (3).

5. The acrylic acid oxidation reactor gas sampling device according to claim 1, characterized in that: A second-stage bubbling gas collecting bottle inlet pipe (13) is provided between the first-stage bubbling gas collecting bottle (3) and the second-stage bubbling gas collecting bottle (4). The second-stage bubbling gas collecting bottle inlet pipe (13) extends into the bottom of the second-stage bubbling gas collecting bottle (4). The connection between the second-stage bubbling gas collecting bottle inlet pipe (13) and the first-stage bubbling gas collecting bottle (3) is located at the bottle mouth.

6. The acrylic acid oxidation reactor gas sampling device according to claim 1, characterized in that: A third-stage bubbling gas collecting bottle inlet pipe (14) is provided between the second-stage bubbling gas collecting bottle (4) and the third-stage bubbling gas collecting bottle (5), the third-stage bubbling gas collecting bottle inlet pipe (14) extending into the bottom of the third-stage bubbling gas collecting bottle (5), and the connection between the third-stage bubbling gas collecting bottle inlet pipe (14) and the second-stage bubbling gas collecting bottle (4) is located at the bottle mouth.

7. The acrylic acid oxidation reactor gas sampling device according to claim 1, characterized in that: A gas flow meter inlet pipeline (15) is provided between the three-stage bubbling gas collecting bottle (5) and the gas flow meter (6).

8. The acrylic acid oxidation reactor gas sampling device according to claim 1, characterized in that: The gas flow meter (6) is connected to a secondary gas sampling bag (8) and a tertiary gas sampling bag (9).

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