A constant pressure variable volume method separation membrane gas permeability testing device

Abstract

The utility model relates to the technical field of separation membrane performance test, specifically is a kind of separation membrane gas permeability testing device of constant pressure variable volume method. Including test upper cavity and test lower cavity, test upper cavity includes upper air chamber and surrounds the upper temperature control water jacket of being arranged outside upper air chamber, test lower cavity includes lower air chamber and surrounds the lower temperature control water jacket of being arranged outside lower air chamber, and upper temperature control water jacket and lower temperature control water jacket are all connected with the temperature control mechanism of keeping the temperature constant of upper air chamber and lower air chamber;Pressure detection device and pressure control device for keeping the constant pressure of upper air chamber are equipped on the gas inlet line of upper air chamber, and flow control device is equipped on the gas outlet line of upper air chamber;Flowmeter and gas analyzer are equipped on the gas outlet line of lower air chamber.The utility model can avoid the error introduced in the prior art product, the test gas permeating separation membrane needs carrier gas to be carried to gas analyzer, and the concentration, proportion of multicomponent test gas can be stabilized.

Description

Technical Field

[0001] This utility model relates to the field of separation membrane performance testing technology, specifically a separation membrane gas permeability testing device using the constant pressure variable volume method. Background Technology

[0002] Existing membrane permeability testing devices generally employ a constant volume variable pressure (CVP) method: the membrane divides the test chamber into high-pressure and low-pressure chambers. During the test, the low-pressure chamber is under vacuum, while the high-pressure chamber is filled with test gas and sealed to maintain a certain pressure. The volume of the low-pressure chamber remains constant. As more test gas permeates through the membrane, the pressure in the low-pressure chamber increases, hence the constant volume variable pressure. The test gas permeates through the sample to the low-pressure chamber, which is connected to a carrier gas source. The carrier gas then transports the permeated gas to a gas analyzer for analysis. However, the CNP method has the following drawbacks: 1. Limited range due to the low-pressure chamber sensor's range, making it unsuitable for testing samples with large permeation volumes. Furthermore, the small amount of test gas permeating the membrane cannot directly reach the analyzer and must be transported via a carrier gas. The carrier gas mixing process can easily lead to gas dilution, pipeline leaks, and cross-contamination, affecting detection accuracy. 2. In existing devices, the test gas in the upper chamber is kept closed and pressurized, which cannot maintain a constant concentration of test gas components in real time. The selective permeation of the separation membrane will cause changes in the gas ratio during the permeation process, resulting in distorted test results. 3. The gas in the lower chamber is non-flowing and cannot reflect the membrane performance under real operating conditions. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides a gas permeability testing device for separation membranes using a constant pressure variable volume method. By using the constant pressure variable volume testing method, errors introduced by the carrier gas can be avoided, and the concentration of multi-component gases can be stabilized.

[0004] To solve the aforementioned technical problem, the present invention adopts the following technical solution: a gas permeability testing device for a separation membrane using a constant pressure variable volume method, comprising an upper testing chamber and a lower testing chamber. The upper testing chamber includes an upper gas chamber and an upper temperature-controlled water jacket surrounding the upper gas chamber. The lower testing chamber includes a lower gas chamber and a lower temperature-controlled water jacket surrounding the lower gas chamber. Both the upper and lower temperature-controlled water jackets are connected to a temperature control mechanism to maintain a constant temperature in the upper and lower gas chambers. The inlet pipe of the upper gas chamber is equipped with a pressure detection device and a pressure control device for maintaining a constant pressure in the upper gas chamber. The outlet pipe of the upper gas chamber is equipped with a flow control device. The outlet pipe of the lower gas chamber is equipped with a flow meter and a gas analyzer.

[0005] Furthermore, the temperature control mechanism includes a temperature sensor and a circulating thermostat. The temperature sensor is disposed in the upper temperature control water jacket and / or the lower temperature control water jacket. The temperature sensor and the circulating thermostat are connected in a controllable manner, and the circulating medium chamber of the circulating thermostat is connected to the circulating medium inlet and outlet of the upper temperature control water jacket and / or the lower temperature control water jacket, respectively.

[0006] Furthermore, the upper and lower temperature control water jackets are integrated into a single structure, and are connected to a temperature control mechanism.

[0007] Furthermore, the upper and lower temperature control water jackets are separate structures, with each jacket connected to a different temperature control mechanism.

[0008] Furthermore, one or more flow meters are installed in parallel on the outlet pipe of the lower air chamber, and the multiple flow meters in parallel are connected to the gas analyzer through a reversing valve.

[0009] Furthermore, both the upper and lower temperature control water jackets are equipped with cover plates, and sealing rings are provided between the cover plates and the main bodies of the upper and lower temperature control water jackets.

[0010] Furthermore, the pressure detection device is a pressure sensor.

[0011] Furthermore, the pressure control device is a pressure regulating valve, which includes a proportional valve, an electronic pressure regulating valve, and a pressure controller.

[0012] Furthermore, the flow control device is an electronically or mechanically regulated flow valve or a mass flow controller.

[0013] Furthermore, the gas analyzer is a gas chromatograph and / or a mass spectrometer.

[0014] The beneficial effects of this invention are as follows: The device described in this invention uses the constant pressure variable volume method to test the permeability of the separation membrane. A flow control device in the upper chamber maintains dynamic gas flow, and a pressure regulation module stabilizes the concentration of multiple components. The permeated gas in the lower chamber is directly delivered to the analytical instrument, avoiding errors introduced by the carrier gas. The device supports positive pressure testing and can analyze the composition of the permeated gas in real time, making it suitable for high-precision, multi-scenario performance evaluation of separation membranes. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the test device described in Example 1;

[0016] Figure 2 This is a schematic diagram of the test device described in Example 2;

[0017] Figure 3 This is a magnified schematic diagram of the upper and lower test chambers;

[0018] In the diagram: 1. Test gas source, 2. Solenoid valve, 3. Pressure control device, 4. Pressure detection device, 5. Circulating thermostat, 6. Upper test chamber, 7. Flow control device, 8. Sample, 9. Lower test chamber, 10. Gas analyzer, 11. Flow detection device I, 12. Flow detection device II, 13. Reversing valve, 14. Upper temperature-controlled water jacket, 15. Upper gas chamber, 16. Upper temperature-controlled water jacket cover plate, 17. Upper temperature-controlled water jacket circulating medium inlet, 18. Upper temperature-controlled water jacket circulating medium outlet, 19. Test gas inlet, 20. Test gas outlet, 21. Lower temperature-controlled water jacket, 22. Lower gas chamber, 23. Lower temperature-controlled water jacket circulating medium inlet, 24. Lower temperature-controlled water jacket circulating medium outlet, 25. Permeable gas outlet, 26. Lower temperature-controlled water jacket cover plate, 27. Sealing ring, 28. Temperature sensor. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1

[0021] This embodiment discloses a gas permeability testing device for a separation membrane using the constant pressure variable volume method. The device tests the permeability performance of the separation membrane using this method. Figure 1 , 3 As shown, the test chamber includes an upper chamber 6 and a lower chamber 9. The upper chamber 6 is the high-pressure side, including an upper gas chamber 15 and an upper temperature-controlled water jacket 14 surrounding the upper gas chamber 15. The upper gas chamber 15 has a test gas inlet 19 and a test gas outlet 20. The test gas inlet 19 is connected to a test gas source 1, a solenoid valve 2, a pressure control device 3, and a pressure detection device 4. The test gas source 1 is filled with test gas and is used to introduce test gas into the upper gas chamber 15. The solenoid valve 2 is located on the gas supply line and is used to control the opening and closing of the introduced test gas. The pressure detection device 3 is a pressure sensor used to monitor and feedback pressure data in real time. The pressure control device 3 is a pressure regulating valve, such as a proportional valve, an electronic pressure regulator, or a pressure controller, used to maintain a constant pressure in the upper chamber 6. A flow control device 12 is provided on the test gas outlet line of the upper chamber 15. The flow control device 12 is an electronically or mechanically regulated flow valve or a mass flow controller used to ensure continuous gas flow in the upper chamber 6 and avoid the formation of a gas concentration gradient on the membrane surface. The upper temperature control water jacket 14 is provided with an upper temperature control water jacket cover plate 16. A sealing ring 27 is provided between the upper temperature control water jacket cover plate and the body of the upper temperature control water jacket 14. The cover plate makes the upper temperature control water jacket 14 easy to repair and maintain, and the sealing ring 27 maintains the sealing performance of the upper temperature control water jacket 14.

[0022] The lower chamber 9 is the low-pressure side, including a lower gas chamber 22 and a lower temperature-controlled water jacket 21 surrounding the lower gas chamber 22. The lower gas chamber 22 has a permeable gas outlet 25, and a flow meter I11 and a gas analyzer 10 are installed on the permeable gas outlet 25, which is the outlet pipe of the lower gas chamber 22. In this embodiment, a single-range flow meter I11 is used to directly measure the volumetric flow rate of the permeable gas. The gas analyzer 10 is a gas chromatograph and / or a mass spectrometer. In this embodiment, the permeable gas is delivered to the external gas analyzer 10 (such as a gas chromatograph or mass spectrometer) through the permeable gas outlet 25 of the lower gas chamber 22, the flow meter I11, and related pipelines, without the need for a carrier gas transfer. The lower temperature control water jacket 21 is provided with a lower temperature control water jacket cover plate 26. A sealing ring 27 is provided between the lower temperature control water jacket cover plate and the body of the lower temperature control water jacket 21. The cover plate makes the lower temperature control water jacket 21 easy to repair and maintain, and the sealing ring 27 maintains the sealing performance of the lower temperature control water jacket 21.

[0023] Both the upper temperature-controlled water jacket 14 and the lower temperature-controlled water jacket 21 are connected to a temperature control mechanism that maintains a constant temperature in the upper air chamber 15 and the lower air chamber 22. The temperature control mechanism includes a temperature sensor 28 and a circulating thermostat 5. The temperature sensor 28 is disposed in the upper temperature-controlled water jacket 14 and / or the lower temperature-controlled water jacket 21. The temperature sensor 28 and the circulating thermostat 5 are connected in a controlled manner, and the circulating medium chamber of the circulating thermostat 5 is connected to the inlet and outlet of the circulating medium of the upper temperature-controlled water jacket and / or the lower temperature-controlled water jacket, respectively.

[0024] In this embodiment, the upper temperature-controlled water jacket 14 and the lower temperature-controlled water jacket 21 are separate structures, each connected to a different temperature control mechanism. Specifically, the upper temperature-controlled water jacket 14 has an upper temperature-controlled water jacket circulating medium inlet 17 and an upper temperature-controlled water jacket circulating medium outlet 18, which are respectively connected to the circulating medium chamber of the circulating thermostat 5. The lower temperature-controlled water jacket 21 has a lower temperature-controlled water jacket circulating medium inlet 23 and an upper and lower temperature-controlled water jacket circulating medium outlet 24, which are respectively connected to the circulating medium chamber of another circulating thermostat. In other embodiments, the upper temperature-controlled water jacket 14 and the lower temperature-controlled water jacket 21 can also be an integrated structure, connected to a single temperature control mechanism.

[0025] During operation, the test gas enters the upper chamber 15 and forms high pressure. An upper temperature-controlled water jacket 14 surrounds the outside of the upper chamber 15, and the circulating medium circulates within the upper temperature-controlled water jacket 14. Temperature sensor 28 detects the temperature, and the circulating thermostat 5 adjusts the temperature of the upper chamber 15 in real time to maintain a constant temperature. After permeating the sample, the test gas enters the lower chamber 22, which is connected to a flow meter to detect the flow rate of the test gas permeating the sample. The lower circulating medium circulates within the lower temperature-controlled water jacket 21, and temperature sensor 28 detects the temperature. The circulating thermostat 5 adjusts the temperature of the lower chamber 22 in real time to maintain a constant temperature.

[0026] The steps for testing the permeability of the separation membrane using this device are as follows:

[0027] 1. Clamping the sample: Fix the sample 8 to be tested between the upper test chamber 6 and the lower test chamber 9, and press the upper test chamber 6 and the lower test chamber 9 to seal the sample 8.

[0028] 2. Inflate the upper chamber 6 with gas: Introduce test gas (such as CO2 / N2 mixture) into the upper chamber 6 and set the target pressure (such as 0.5MPa) through the pressure control device 3.

[0029] 3. Dynamic balance: Activate the flow control device 7 to ensure continuous circulation of gas in the upper test chamber 6, avoiding local concentration changes.

[0030] 4. Permeation monitoring: The flow meter 11 connected to the lower chamber 9 records the permeation gas volume in real time, while the gas analyzer 10 detects the gas composition in real time.

[0031] 5. Data processing: Calculate the permeability based on the flow data and evaluate the membrane selectivity in conjunction with the component analysis results.

[0032] Example 2

[0033] In this embodiment, two flow meters are installed in parallel on the outlet pipe of the lower air chamber 21, namely... Figure 2 The gas analyzer 10 is connected in parallel to flow meters I11 and II12 via a reversing valve 13. Using dual flow meters allows for accommodating both large and small flow ranges, ensuring accuracy for small-range samples and expanding the testable range for large-range samples. The reversing valve 13 switches which flow meter's gas enters the gas analyzer 10. Other structural features in this embodiment are the same as in Embodiment 1 and will not be repeated here.

[0034] The testing device described in this invention maintains dynamic gas flow through a flow control device in the upper testing chamber and achieves stable concentration of multi-component gases through a pressure regulation module. The permeate gas in the lower testing chamber is directly delivered to the analytical instrument, avoiding errors introduced by the carrier gas. This device can analyze the permeate gas composition in real time and is suitable for high-precision, multi-scenario performance evaluation of separation membranes. Both the upper and lower testing chambers are equipped with temperature-controlled water jackets, which maintain a constant temperature in the testing chambers during the testing process, making it particularly suitable for dynamic monitoring and analysis of the permeation process of multi-component mixed gases.

[0035] The above description is only the basic principle and preferred embodiment of this utility model. Any improvements and substitutions made by those skilled in the art based on this utility model shall fall within the protection scope of this utility model.

Claims

1. A device for testing the gas permeability of a separation membrane using a constant pressure variable volume method, characterized in that: The test chamber includes an upper test chamber and a lower test chamber. The upper test chamber includes an upper air chamber and an upper temperature-controlled water jacket surrounding the upper air chamber. The lower test chamber includes a lower air chamber and a lower temperature-controlled water jacket surrounding the lower air chamber. Both the upper and lower temperature-controlled water jackets are connected to temperature control mechanisms to maintain a constant temperature in the upper and lower air chambers. The upper air chamber's inlet pipe is equipped with a pressure detection device and a pressure control device to maintain a constant pressure in the upper air chamber. The upper air chamber's outlet pipe is equipped with a flow control device. The lower air chamber's outlet pipe is equipped with a flow meter and a gas analyzer.

2. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 1, characterized in that: The temperature control mechanism includes a temperature sensor and a circulating thermostat. The temperature sensor is installed in the upper and / or lower temperature control water jacket and monitors the temperature of the cavity in real time. The circulating medium inlet and outlet of the circulating thermostat are respectively connected to the circulating medium inlet and outlet of the upper and / or lower temperature control water jacket.

3. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 2, characterized in that: The upper and lower temperature control water jackets are integrated into one unit, and are connected to a temperature control mechanism.

4. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 2, characterized in that: The upper and lower temperature control water jackets are separate structures, and they are connected to different temperature control mechanisms respectively.

5. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 1, characterized in that: The lower air chamber has one or more parallel flow meters on its outlet pipe, and the parallel flow meters are connected to the gas analyzer through a reversing valve.

6. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 1, characterized in that: Both the upper and lower temperature control water jackets are equipped with cover plates, and sealing rings are provided between the cover plates and the bodies of the upper and lower temperature control water jackets.

7. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 1, characterized in that: The pressure detection device is a pressure sensor.

8. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 1, characterized in that: The pressure control device is a pressure regulating valve, which includes a proportional valve, an electronic pressure regulating valve, and a pressure controller.

9. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 1, characterized in that: The flow control device is an electronically or mechanically regulated flow valve or mass flow controller.

10. The gas permeability testing device for a separation membrane using the constant pressure variable volume method according to claim 1, characterized in that: The gas analyzer is a gas chromatograph and / or a mass spectrometer.

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