Automatic enrichment device for ultra-trace gas

Abstract

The utility model discloses an automatic enrichment device for ultra-trace gas, which relates to the technical field of gas analysis and comprises a first cold trap enrichment module, a second cold trap enrichment module, a gas carrying bottle, a chromatographic instrument, a controller and a plurality of three-way valves which are all mounted on a main body frame, the carrier gas bottle is connected with the two cold trap enrichment modules through a three-way valve I, and the chromatograph is connected with the two cold trap enrichment modules through a three-way valve II; the two cold trap enrichment modules respectively comprise a gas sample introduction unit, a cold trap enrichment unit and a six-way valve, and share one controller; the gas sample introduction unit can remove gas impurities, the cold trap enrichment unit can efficiently enrich ultra-trace gas, the pressure sensor monitors the pressure of a cold trap in real time, and the flow regulating valve is triggered to regulate the flow rate when the pressure is abnormal; full-process automatic operation is achieved, and manual errors and pollution are avoided; the enrichment effect is remarkably improved through the double-cold-trap design; the gas dryer and the electromagnetic valve are matched to effectively remove impurities and guarantee the detection accuracy.

Description

Technical Field

[0001] This utility model relates to the field of gas analysis technology, specifically an automatic enrichment device for ultra-trace gases. Background Technology

[0002] Phosphine is of great significance to the biogeochemical cycle of phosphorus, but its quantitative analysis has been slow due to its strong reducing properties, low concentration, and difficulty in separation, which seriously restricts the research on the phosphorus cycle.

[0003] Currently, methods for detecting phosphine have significant shortcomings. Chemical detection methods, such as colorimetry and entropy determination, are simple to operate but lack qualitative analysis and accuracy, and are only suitable for detecting high concentrations of phosphine. Modern instruments such as gas chromatography (GC) and mass spectrometry (MS) can perform qualitative and quantitative analysis, but their measurement range is limited, making it difficult to meet the detection needs of trace phosphine in the environment. Although there are methods that combine pre-column low-temperature cold trap enrichment pretreatment with GC-NDP to lower the detection limit, most cold trap enrichment devices for trace and ultra-trace phosphine gases rely on manual operation, resulting in low efficiency, susceptibility to contamination, poor enrichment of trace components, and slow response when changing cold traps, adjusting flow and pressure, making it difficult to achieve rapid enrichment and high-sensitivity detection. In addition, there are few pretreatment devices on the market for small-molecule, non-volatile, ultra-trace gases such as phosphine. The few existing testing methods are cumbersome to operate manually, and semi-automated auxiliary equipment involves lengthy experimental steps, consumes toxic reagents, poses hazards to personnel and the environment, and has low validity and repeatability of analytical results. Therefore, there is an urgent need for an automated ultra-trace gas enrichment device to address the shortcomings of existing technologies in the analysis and detection of phosphine gas. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic enrichment device for ultra-trace gases to solve the problems raised in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an automatic enrichment device for ultra-trace gases, which includes a main frame, a first cold trap enrichment module, a second cold trap enrichment module, a carrier gas bottle, a chromatograph, a controller, a flow regulating valve, a three-way valve one, and a three-way valve two.

[0006] The first cold trap enrichment module and the second cold trap enrichment module have the same structure and are symmetrically distributed;

[0007] The first cold trap enrichment module, the second cold trap enrichment module, the carrier gas cylinder, the chromatograph, the controller, the flow control valve, and the three-way valve one and the three-way valve two are all mounted on the main frame.

[0008] The aforementioned carrier gas cylinder is a nitrogen carrier gas cylinder, used to clean the entire flow path of the device.

[0009] Furthermore, both the first cold trap enrichment module and the second cold trap enrichment module include a gas injection unit, a cold trap enrichment unit, and a six-way valve, respectively.

[0010] The gas injection unit and the cold trap enrichment unit are connected by a six-way valve.

[0011] Furthermore, the gas injection unit includes an experimental gas inlet, a pipeline switch, a gas dryer, a solenoid valve, a three-way valve, and a gas flow meter;

[0012] The second end of solenoid valve one is connected to the first port of three-way valve three. The first end of the pipeline switch is connected to the experimental gas inlet. The second end of the pipeline switch is connected to the gas dryer. The gas dryer is connected to the second port of three-way valve three. The third port of three-way valve three is connected to port 2 of six-way valve. The gas flow meter is installed between the first end of solenoid valve one and the first port of three-way valve one.

[0013] The gas dryer of this invention is an adsorption tube equipped with a specific adsorption material, used to remove impurities such as moisture and carbon dioxide from the gas.

[0014] Furthermore, the cold trap enrichment unit includes solenoid valve 2, cold trap 1, solenoid valve 3, cold trap 2, solenoid valve 4, solenoid valve 5, three-way valve 4, air outlet, and pressure sensor.

[0015] The first end of solenoid valve 2 is connected to port 3 of the six-way valve. The second end of solenoid valve 2 is connected to the inlet of cold trap 1. The outlet of cold trap 1 is connected to port 6 of the six-way valve. Port 1 of the six-way valve is connected to the first end of solenoid valve 3. The second end of solenoid valve 3 is connected to the inlet of cold trap 2. The outlet of cold trap 2 is connected to the first port of three-way valve 4. The second port of three-way valve 4 is connected to the first end of solenoid valve 5. The third port of three-way valve 4 is connected to the first end of solenoid valve 4. The second end of solenoid valve 4 is connected to port 5 of the six-way valve. Port 4 of the six-way valve is connected to the air outlet. The pressure sensor is located at the outlet of cold trap 1.

[0016] Furthermore, the first cold trap enrichment module and the second cold trap enrichment module share the same controller;

[0017] The controller is connected to solenoid valve 1, solenoid valve 2, solenoid valve 3, solenoid valve 4, solenoid valve 5, and pressure sensor.

[0018] Furthermore, the carrier gas cylinder is connected to the first end of the flow control valve; the second end of the flow control valve is connected to the third port of the three-way valve; and the chromatograph is connected to the third port of the three-way valve.

[0019] Furthermore, the first end of solenoid valve one in the first cold trap enrichment module is connected to the first port of three-way valve one, and the first end of solenoid valve one in the second cold trap enrichment module is connected to the second port of three-way valve one; the second end of solenoid valve five in the first cold trap enrichment module is connected to the first port of three-way valve two, and the second end of solenoid valve five in the second cold trap enrichment module is connected to the second port of three-way valve two.

[0020] This invention uses a pressure sensor to monitor the cold trap pressure in real time. If an abnormality occurs, it triggers a flow regulating valve to adjust the flow rate.

[0021] Compared with the prior art, the beneficial effects of this utility model are:

[0022] 1. High degree of automation

[0023] This invention integrates a first cold trap enrichment module, a second cold trap enrichment module, a carrier gas cylinder, a chromatograph, and other related components. Through a controller, it regulates solenoid valves one through five, as well as a pressure sensor and a gas flow meter, achieving fully automated operation from gas injection, enrichment, impurity removal to detection. This not only greatly improves work efficiency but also avoids the errors and contamination risks associated with manual operation compared to traditional manually operated trace and ultra-trace phosphine gas cold trap enrichment devices. Regarding gas pretreatment time, traditional phosphine pre-enrichment technology requires 25 minutes, while this invention only requires 5 minutes, significantly shortening the processing time and further demonstrating its high efficiency brought by automation.

[0024] 2. Excellent enrichment effect

[0025] A dual cold trap enrichment module is configured, consisting of a first cold trap enrichment module and a second cold trap enrichment module, with each module equipped with a dedicated cold trap one and a cold trap two. During the gas enrichment process, the cold traps can efficiently capture and concentrate ultra-trace phosphine gas, significantly improving the enrichment effect of trace components. In terms of recovery rate, the recovery rate of traditional phosphine pre-enrichment technology is only 50%, while the recovery rate of this invention can reach 80%-100%. This data fully demonstrates the superior performance of this invention in enriching ultra-trace gases, enabling more effective enrichment of target gases and improving the reliability of detection.

[0026] 3. Effective removal of impurities

[0027] The gas dryer in the gas injection unit uses an adsorption tube with specific adsorption material to effectively remove impurities such as moisture and carbon dioxide from the gas. During the enrichment process, the orderly opening and closing of the solenoid valve further clarifies the impurities, ensuring high purity of the gas entering the chromatograph, reducing interference from impurities on the detection results, and improving the accuracy of the detection results.

[0028] 4. High detection accuracy and low sample injection requirements

[0029] Regarding the accuracy of the collaborative detection equipment, this invention controls the temperature precisely to 1℃ and maintains a stable carrier gas flow rate of 1mL / min. Compared to traditional technologies where the temperature control accuracy is only 5℃ and the carrier gas flow is uncontrollable, this invention can more accurately control the detection conditions and ensure the accuracy of the detection results. In addition, the gas injection requirement of this invention is only 10-15mL, which is much lower than the requirement of more than 50ml in traditional technologies, reducing the sample volume requirement and providing a significant advantage when samples are scarce. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of an automatic ultra-trace gas enrichment device according to the present invention;

[0031] Figure 2 This is a diagram showing the valve switching and gas flow path of an automatic ultra-trace gas enrichment device according to this utility model.

[0032] In the diagram: 1. Experimental gas inlet; 2. Pipeline switch; 3. Gas dryer; 4. Six-way valve; 5. Pressure sensor; 6. Controller; 7. Gas flow meter; 8. Carrier gas cylinder; 9. Chromatograph; 10. Gas outlet; 11. Flow regulating valve; 12. Solenoid valve one; 13. Solenoid valve two; 14. Solenoid valve three; 15. Solenoid valve four; 16. Solenoid valve five; 17. Three-way valve one; 18. Three-way valve two; 19. Three-way valve three; 20. Three-way valve four; 21. Cold trap one; 22. Cold trap two. Detailed Implementation

[0033] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0034] Example: Figures 1-2 As shown, this utility model provides a technical solution: an automatic enrichment device for ultra-trace gases. The device includes a main frame, a first cold trap enrichment module, a second cold trap enrichment module, a carrier gas cylinder 8, a chromatograph 9, a controller 6, a flow regulating valve 11, a three-way valve one 17, and a three-way valve two 18.

[0035] The first cold trap enrichment module and the second cold trap enrichment module have the same structure and are symmetrically distributed;

[0036] The first cold trap enrichment module, the second cold trap enrichment module, the carrier gas cylinder 8, the chromatograph 9, the controller 7, the flow regulating valve 11, the three-way valve one 17 and the three-way valve two 18 are all installed on the main frame.

[0037] The first cold trap enrichment module and the second cold trap enrichment module each include a gas injection unit, a cold trap enrichment unit, and a six-way valve 4.

[0038] The gas injection unit and the cold trap enrichment unit are connected by a six-way valve 4;

[0039] The gas injection unit includes an experimental gas inlet 1, a pipeline switch 2, a gas dryer 3, a solenoid valve 12, a three-way valve 319, and a gas flow meter 7.

[0040] The second end of solenoid valve 12 is connected to the first port of three-way valve 19. The first end of pipeline switch 2 is connected to experimental gas inlet 1. The second end of pipeline switch 2 is connected to gas dryer 3. Gas dryer 3 is connected to the second port of three-way valve 19. The third port of three-way valve 19 is connected to port 2 of six-way valve 4. Gas flow meter 7 is installed between the first end of solenoid valve 12 and the first port of three-way valve 17.

[0041] The cold trap enrichment unit includes solenoid valve 2 (13), cold trap 1 (21), solenoid valve 3 (14), cold trap 2 (22), solenoid valve 4 (15), solenoid valve 5 (16), three-way valve 4 (20), air outlet (10), and pressure sensor (5).

[0042] The first end of solenoid valve 213 is connected to port 3 of six-way valve 4. The second end of solenoid valve 213 is connected to the inlet of cold trap 121. The outlet of cold trap 121 is connected to port 6 of six-way valve 4. Port 1 of six-way valve 4 is connected to the first end of solenoid valve 314. The second end of solenoid valve 314 is connected to the inlet of cold trap 22. The outlet of cold trap 22 is connected to the first port of three-way valve 420. The second port of three-way valve 420 is connected to the first end of solenoid valve 516. The third port of three-way valve 420 is connected to the first end of solenoid valve 415. The second end of solenoid valve 415 is connected to port 5 of six-way valve 4. Port 4 of six-way valve 4 is connected to the air outlet. Pressure sensor 5 is installed at the outlet of cold trap 121.

[0043] The first cold trap enrichment module and the second cold trap enrichment module share a single controller 6.

[0044] The controller 6 is connected to solenoid valve 12, solenoid valve 23, solenoid valve 34, solenoid valve 45, solenoid valve 516, and pressure sensor 5.

[0045] Among them, the carrier gas cylinder 8 is connected to the first end of the flow regulating valve 11; the second end of the flow regulating valve 11 is connected to the third port of the three-way valve 17; and the chromatograph 9 is connected to the third port of the three-way valve 18.

[0046] In the first cold trap enrichment module, the first end of solenoid valve 12 is connected to the first port of three-way valve 17, and the first end of solenoid valve 12 in the second cold trap enrichment module is connected to the second port of three-way valve 17; the second end of solenoid valve 16 in the first cold trap enrichment module is connected to the first port of three-way valve 18, and the second end of solenoid valve 16 in the second cold trap enrichment module is connected to the second port of three-way valve 18.

[0047] In an embodiment of this utility model, the working process of the device is as follows:

[0048] Step 1: Initial state, solenoid valves 13, 14, and 15 are open, solenoid valve 12 and 16 are closed, the worktables of cold trap 21 and cold trap 22 are in the low position, and the six-way valve 4 is in the ON position (e.g., Figure 2 (as shown)

[0049] Step 2: When the device is powered on and the pipeline switch is turned on, the worktables of Cold Trap 1 21 and Cold Trap 2 22 rise, and the six-way valve 4 is in the OFF state (e.g., Figure 2 As shown), the gas pipeline is cooled for time T1.

[0050] Step 3: The experimenter injects the experimental gas into the pipeline through the experimental gas inlet 1 using a syringe and presses the execution button. At this time, the solenoid valve 12 opens for time T2, and a certain volume of carrier gas is introduced to carry the experimental gas into the cold trap 1 21 and the cold trap 2 22. After the gas is introduced, the solenoid valve 12, solenoid valve 2 13, solenoid valve 3 14, and solenoid valve 4 15 are closed.

[0051] Step 4: After solenoid valve 12, solenoid valve 23, solenoid valve 34, and solenoid valve 45 are closed, control the cooling time T3 of cold trap 121 and cold trap 22.

[0052] Step 5: After cooling is complete, solenoid valve 4 15, solenoid valve 3 14, solenoid valve 2 13 and solenoid valve 1 12 are opened in sequence for ventilation time T4 (purification).

[0053] Step 6: After ventilation is completed, solenoid valve 12 and solenoid valve 23 are closed in sequence; the cold trap 21 workbench descends and the cold trap 21 is heated for time T5.

[0054] Step 7: After the cold trap 21 has finished heating, solenoid valves 14 and 15 are closed. At this time, the control panel will provide a certain prompt (e.g., the output button lights up).

[0055] Step 8: When the experimenter presses the output button, solenoid valve 516 opens, the worktable of cold trap 22 descends, and the heating time T6 is controlled by the resistance wire (the heated and purified gas enters the chromatograph).

[0056] Step 9: After heating is complete, solenoid valve 14, solenoid valve 13, and solenoid valve 12 are opened in sequence to introduce T7 time carrier gas and purify the entire pipeline.

[0057] Step 10: After purification is complete, solenoid valve 12 and solenoid valve 516 are closed, solenoid valve 415 is opened, and the device returns to its initial state.

[0058] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An automated ultra-trace gas enrichment device, characterized in that: The device includes a main frame, a first cold trap enrichment module, a second cold trap enrichment module, a carrier gas cylinder (8), a chromatograph (9), a controller (6), a flow regulating valve (11), a three-way valve one (17), and a three-way valve two (18). The first cold trap enrichment module and the second cold trap enrichment module have the same structure and are symmetrically distributed; The first cold trap enrichment module, the second cold trap enrichment module, the carrier gas cylinder (8), the chromatograph (9), the controller (6), the flow regulating valve (11), the three-way valve one (17) and the three-way valve two (18) are all installed on the main frame.

2. The ultra-trace gas automatic enrichment device according to claim 1, characterized in that: Both the first cold trap enrichment module and the second cold trap enrichment module include a gas injection unit, a cold trap enrichment unit, and a six-way valve (4). The gas injection unit and the cold trap enrichment unit are connected by the six-way valve (4).

3. The ultra-trace gas automatic enrichment device according to claim 2, characterized in that: The gas injection unit includes an experimental gas inlet (1), a pipeline switch (2), a gas dryer (3), a solenoid valve (12), a three-way valve (19), and a gas flow meter (7). The second end of the solenoid valve (12) is connected to the first port of the three-way valve (19). The first end of the pipeline switch (2) is connected to the experimental gas inlet (1). The second end of the pipeline switch (2) is connected to the gas dryer (3). The gas dryer (3) is connected to the second port of the three-way valve (19). The third port of the three-way valve (19) is connected to the second port of the six-way valve (4). The gas flow meter (7) is located between the first end of the solenoid valve (12) and the first port of the three-way valve (17).

4. The ultra-trace gas automatic enrichment device according to claim 3, characterized in that: The cold trap enrichment unit includes solenoid valve 2 (13), cold trap 1 (21), solenoid valve 3 (14), cold trap 2 (22), solenoid valve 4 (15), solenoid valve 5 (16), three-way valve 4 (20), air outlet (10), and pressure sensor (5). The first end of the second solenoid valve (13) is connected to port 3 of the six-way valve (4), the second end of the second solenoid valve (13) is connected to the inlet of the first cold trap (21), the outlet of the first cold trap (21) is connected to port 6 of the six-way valve (4), port 1 of the six-way valve (4) is connected to the first end of the third solenoid valve (14), the second end of the third solenoid valve (14) is connected to the inlet of the second cold trap (22), the outlet of the second cold trap (22) is connected to the first port of the fourth three-way valve (20), the second port of the fourth three-way valve (20) is connected to the first end of the fifth solenoid valve (16), the third port of the fourth three-way valve (20) is connected to the first end of the fourth solenoid valve (15), the second end of the fourth solenoid valve (15) is connected to port 5 of the six-way valve (4), port 4 of the six-way valve (4) is connected to the air outlet, and the pressure sensor (5) is located at the outlet of the first cold trap (21).

5. The ultra-trace gas automatic enrichment device according to claim 4, characterized in that: The first cold trap enrichment module and the second cold trap enrichment module share the same controller (6). The controller (6) is connected to the first solenoid valve (12), the second solenoid valve (13), the third solenoid valve (14), the fourth solenoid valve (15), the fifth solenoid valve (16), and the pressure sensor (5).

6. The ultra-trace gas automatic enrichment device according to claim 1, characterized in that: The carrier gas cylinder (8) is connected to the first end of the flow regulating valve (11); the second end of the flow regulating valve (11) is connected to the third port of the three-way valve (17); the chromatograph (9) is connected to the third port of the three-way valve (18).

7. The ultra-trace gas automatic enrichment device according to claim 1, characterized in that: The first end of the solenoid valve 1 (12) in the first cold trap enrichment module is connected to the first port of the three-way valve 1 (17), and the first end of the solenoid valve 1 (12) in the second cold trap enrichment module is connected to the second port of the three-way valve 1 (17); the second end of the solenoid valve 5 (16) in the first cold trap enrichment module is connected to the first port of the three-way valve 2 (18), and the second end of the solenoid valve 5 (16) in the second cold trap enrichment module is connected to the second port of the three-way valve 2 (18).

Images