A gas mixing device for organic gas standard substance

Abstract

The utility model provides a kind of gas device of organic standard substance, the device includes cleaning module, drying module, organic solvent bottle, precision metering pump, vaporization chamber, MFC, drainage pump, vacuum pump, conveying pipe, target gas bottle and controller;Cleaning module and organic solvent bottle are connected with conveying pipe, organic solvent bottle is also equipped with organic solvent supply valve between conveying pipe;The both ends of conveying pipe are equipped with first valve and second valve, drying module is connected with first valve, vacuum pump is connected with second valve;Precision metering pump, vaporization chamber and MFC are arranged on conveying pipe, the front end and rear end of vaporization chamber are equipped with front end feeding valve and rear end discharge valve;MFC is connected with rear end discharge valve;Target gas bottle is connected with conveying pipe;Drainage pump is connected between MFC and rear end discharge valve.The utility model realizes high-efficiency accurate controllable by integration and automation design, reduces toxic reagent contact by airtight design, improves operation safety, meets laboratory specification.

Description

Technical Field

[0001] This utility model relates to the field of quantitative preparation technology of standard gases, and in particular to a gas mixing device for organic gas standard substances. Background Technology

[0002] The widespread use of organic liquids in industrial production and environmental media has brought about significant safety and health risks. Most organic solvents are volatile, toxic, or flammable; their vapors can enter the human body through inhalation, skin contact, etc., causing acute or chronic health damage. Long-term exposure to these substances may lead to chronic poisoning, organ dysfunction, and even increased cancer risk. Furthermore, some organic compounds, as important precursors to photochemical smog and near-ground ozone pollution, have a significant destructive effect on the atmospheric environment. Therefore, accurate monitoring and effective control of organic gases have become urgent tasks in the fields of environmental protection, occupational health, and public safety.

[0003] Against this backdrop, the development of accurate and traceable organic gas reference materials (organic gas reference materials possess homogeneity, stability, and accurate values), such as ethanol gas reference materials in the air and toluene gas reference materials in nitrogen, is of significant scientific and practical value. These reference materials are not only the technical foundation for calibrating analytical instruments and verifying detection methods, but also crucial metrological bases for achieving precise monitoring of organic pollutants, conducting exposure risk assessments, and supporting environmental policy formulation.

[0004] Traditionally, in the preparation of organic gas standard substances, the liquid injection method is typically used. The liquid is weighed and directly fed into a gas mixing device for heating and vaporization into the corresponding gas. The specific procedure is as follows: First, a needle is installed on an empty syringe. A certain volume of high-purity organic solvent is transferred, the needle is replaced, and the syringe mass before liquid injection is weighed using an analytical balance and recorded. Then, the organic solvent is injected through a sealed septum into the target gas cylinder or filling pipeline, which has undergone vacuum treatment. The injection port and pipeline are heated to rapidly vaporize the liquid, ultimately storing it in a gaseous form. After injection, the syringe mass is weighed again using an analytical balance and recorded. The actual amount of organic solvent injected can be calculated from the difference between the two weighings. The method has the following obvious limitations: (1) The operation process is complicated, involving multiple weighing and needle changing steps, which takes a long time; (2) It is difficult to completely avoid errors introduced by human operation during the process of pipetting and changing needles, which are manifested as volume reading deviation, weighing value fluctuation, etc.; (3) Only the liquid part is metered, and the gas delivery control is not realized, resulting in insufficient gas concentration accuracy control.

[0005] In view of this, there is an urgent need to study a gas mixing device that can effectively improve the accuracy of organic gas standard values. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a gas mixing device for organic gas standard substances, which can realize the automated and accurate metering, lossless transfer and controllable vaporization process of liquids, effectively improving the preparation accuracy, operation efficiency and safety, and providing technical support for the reliable development of standard substances.

[0007] In a first aspect, this utility model provides a gas mixing device for organic gas standard substances, including a cleaning module, a drying module, an organic solvent bottle, a precision metering pump, a vaporization chamber, an MFC, a drain pump, a vacuum pump, a delivery pipe, a target gas bottle, and a controller. Both the cleaning module and the organic solvent bottle are connected to the delivery pipe, and an organic solvent supply valve is also provided between the organic solvent bottle and the delivery pipe. The two ends of the conveying pipe are respectively equipped with a first valve and a second valve. The drying module is connected to the first valve, and the vacuum pump is connected to the second valve. Along the flow direction of the organic solvent, the precision metering pump, the vaporization chamber and the MFC are sequentially arranged on the conveying pipe, and the front end and the rear end of the vaporization chamber are respectively provided with a front feed valve and a rear discharge valve. The MFC is electrically connected to the back-end discharge valve for control. The target gas cylinder is connected to the end of the delivery pipe near the vacuum pump via a first branch pipe, and the first branch pipe is equipped with an inlet valve. The drainage pump is connected between the MFC and the rear discharge valve through a second branch pipe, and a drainage pump valve is provided on the second branch pipe. The cleaning module, drying module, precision metering pump, vaporization chamber, MFC, drain pump, vacuum pump, first valve, second valve, front feed valve, air inlet valve, and drain pump valve are all connected to the controller and controlled by the controller.

[0008] Furthermore, the cleaning module includes an ultrapure water bottle containing ultrapure water and an ultrapure water supply valve, wherein the ultrapure water supply valve is connected to and controlled by the controller. The ultrapure water bottle is connected to the end of the delivery pipe near the first valve via a third branch pipe, and the ultrapure water supply valve is located on the third branch pipe.

[0009] Furthermore, it also includes a filter connected to the front end of the precision metering pump.

[0010] Furthermore, the drying module is a hot air blower.

[0011] Furthermore, the first branch pipe is also equipped with a thermometer and a pressure gauge, which are respectively connected to the controller and controlled by the controller.

[0012] Furthermore, the delivery pipe is also connected to an exhaust pipe, which is also connected to an exhaust valve. The exhaust valve is connected to and controlled by the controller.

[0013] This utility model has the following advantages: This invention achieves highly efficient operation through integrated and automated design, simplifying traditional cumbersome manual operations (such as multiple weighings and needle replacements), shortening the preparation time per batch, and laying the foundation for rapid, large-scale development of standard substances. It also achieves precise liquid measurement, improving the accuracy and traceability of standard substance values; possesses controllable vaporization capabilities, enabling precise adjustment of vaporization temperature, time, and carrier gas flow rate to ensure the complete and stable conversion of organic solvents into a gaseous state, avoiding inaccurate concentrations caused by uneven vaporization or localized condensation; and enhances operational safety through a closed, integrated design that minimizes direct contact between personnel and toxic volatile reagents, reducing health risks and meeting laboratory safety regulations. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of a gas mixing device for an organic gas standard substance according to the present invention.

[0016] Figure 2 This is a schematic diagram of the connection structure between the controller and its components in this utility model.

[0017] Explanation of the labels in the diagram: 1. Ultrapure water bottle; 2. Ultrapure water supply valve; 3. Filter; 4. Precision metering pump; 5. Front feed valve; 6. Vaporization chamber; 7. Rear discharge valve; 8. Drain pump valve; 9. Drain pump; 10. Organic solvent bottle; 11. Organic solvent supply valve; 12. Hot air blower; 13. First valve; 14. Second valve; 15. Air inlet valve; 16. Vacuum pump; 17. MFC; 19. Thermometer; 20. Pressure gauge; 21. Target gas cylinder; 22. Delivery pipe; 23. Controller; 24. Exhaust valve. Detailed Implementation

[0018] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0019] like Figure 1 and Figure 2As shown, this embodiment provides a gas mixing device for organic gas standard substances, including a cleaning module, a drying module, an organic solvent bottle 10, a precision metering pump 4, a vaporization chamber 6, an MFC 17 (i.e., a mass flow controller), a drain pump 9, a vacuum pump 16, a delivery pipe, a target gas cylinder 21, and a controller 23 (which can use an STM32G0 series chip). The vaporization chamber 6 has a heating and temperature control system (including a heating rod, a heating jacket, a temperature sensor, a temperature controller, a relay, and an overheat protector), which enables trace amounts of liquid organic reagent to undergo a rapid and uniform phase change and be converted into gas within the vaporization chamber 6, ensuring uniform gas concentration.

[0020] Both the cleaning module and the organic solvent bottle 10 are connected to the delivery pipe 22, and an organic solvent supply valve 11 is also provided between the organic solvent bottle 10 and the delivery pipe. The two ends of the conveying pipe are respectively provided with a first valve 13 and a second valve 14. The drying module is connected to the first valve 13, and the vacuum pump 16 is connected to the second valve 14. Along the flow direction of the organic solvent, the precision metering pump 4, the vaporization chamber 6 and the MFC17 are sequentially arranged on the conveying pipe, and the front end and the rear end of the vaporization chamber 6 are respectively provided with a front feed valve 5 and a rear discharge valve 7. The MFC17 is electrically controlled to the rear discharge valve 7; the MFC17 has an internal controller, and the rear discharge valve 7 is connected to the internal controller of the MFC17.

[0021] The target gas cylinder 21 is connected to the end of the delivery pipe near the vacuum pump 16 via a first branch pipe, and an inlet valve 15 is provided on the first branch pipe. The drainage pump 9 is connected between the MFC17 and the rear discharge valve 7 via a second branch pipe, and a drainage pump valve 8 is provided on the second branch pipe. The cleaning module, drying module, precision metering pump 4, vaporization chamber 6, MFC 17, drain pump 9, vacuum pump 16, organic solvent supply valve 11, first valve 13, second valve 14, front feed valve 5, air inlet valve 15 and drain pump valve 8 are respectively connected to the controller and controlled by the controller.

[0022] Specifically, the cleaning module includes an ultrapure water bottle 1 containing ultrapure water and an ultrapure water supply valve 2, wherein the ultrapure water supply valve 2 is connected to a controller and is controlled by the controller. The ultrapure water bottle 1 is connected to the end of the delivery pipe near the first valve 13 via a third branch pipe, and the ultrapure water supply valve 2 is located on the third branch pipe.

[0023] Specifically, it also includes a filter 3, which is connected to the front end of the precision metering pump 4. The filter 3 can trap solid particles, suspended matter, and other impurities in the organic solvent, preventing impurities from entering the vaporization chamber 6 and affecting the vaporization effect or damaging subsequent equipment.

[0024] Specifically, the drying module is a hot air blower 12.

[0025] Specifically, the first branch pipe is also equipped with a thermometer 19 and a pressure gauge 20, which are respectively connected to the controller and controlled by the controller.

[0026] Specifically, the delivery pipe is also connected to an exhaust pipe, which is also connected to an exhaust valve 24. The exhaust valve 24 is connected to a controller and is controlled by the controller.

[0027] During operation, the controller controls the opening of the ultrapure water supply valve 2, the front feed valve 5, the rear discharge valve 7, the drain pump valve 8, and the drain pump 9, so that the ultrapure water in the cleaning module flows to the delivery pipe to clean the delivery pipe, filter 3, precision metering pump 4, and vaporization chamber 6.

[0028] After rinsing twice with ultrapure water, rinse twice with organic solvent. At this time, the controller closes the ultrapure water supply valve 2 and opens the organic solvent supply valve 11, the front feed valve 5, the rear discharge valve 7, the drain pump valve 8, and the drain pump 9, so that the ultrapure water in the organic solvent bottle 10 flows to the delivery pipe to clean the delivery pipe, filter 3, precision metering pump 4, and vaporization chamber 6.

[0029] Then, the controller closes the organic solvent supply valve 11, drain pump valve 8 and drain pump 9, and turns on the hot air blower 12, the first valve 13 and the exhaust valve to dry the delivery pipe, the precision metering pump 4 and the vaporization chamber 6. Subsequently, the controller shuts down the hot air blower 12, the first valve 13 and the exhaust valve, and opens the air inlet valve 15, the second valve 14 and the vacuum pump 16 to perform vacuuming on the pipeline and equipment between the organic solvent bottle 10 and the target gas cylinder 21. After reaching the preset vacuum level, close the air inlet valve 15, the second valve 14, the vacuum pump 16, the front feed valve 5, and the rear discharge valve 7.

[0030] Next, the controller opens the organic solvent supply valve 11 and the precision metering pump 4 to draw a preset dose of organic solvent to the front end of the vaporization chamber 6. Then, the front feed valve 5 is opened to allow the organic solvent temporarily stored at the front of the vaporization chamber 6 to enter the vaporization chamber 6. After that, the front feed valve 5 is closed and the vaporization chamber 6 is started to convert the liquid organic solvent into a gaseous state. Next, the exhaust valve and the inlet valve 15 are opened to allow the gaseous organic solvent to be discharged through the exhaust pipe in order to clean the conveying pipe between the rear discharge valve 7 and the target gas cylinder 21. Subsequently, the exhaust valve is closed, while the inlet valve 15 remains open. The valves of the target gas cylinder 21 and the rear outlet valve 7 are opened, allowing the gaseous organic solvent to be filled into the target gas cylinder 21. During the delivery of the gaseous organic solvent to the target gas cylinder 21, the MFC 17 measures the amount of gaseous organic solvent. Once the preset dosage is reached, the MFC 17 closes the rear outlet valve 7 and sends feedback to the controller, which then closes the inlet valve 15. During the filling process, the thermometer 19 and pressure gauge 20 monitor the temperature and pressure of the first branch pipe, respectively. When the detected values ​​of the temperature and pressure of the first branch pipe exceed the preset upper limit, the controller sends a signal to the internal controller of the MFC 17. The internal controller of the MFC 17 then adjusts the valve opening of the rear outlet valve 7, reducing the flow rate of the gas output from the vaporization chamber 6 and extending the gas delivery time. This ensures that the pipeline conditions remain within a safe range and avoids affecting system stability due to overheating or overpressure.

[0031] This embodiment provides a gas mixing device for an organic gas standard substance, which operates as follows: Step S1: Open the ultrapure water supply valve 2, front feed valve 5, rear discharge valve 7, drain pump valve 8, and drain pump 9 in the cleaning module to allow ultrapure water in the cleaning module to flow to the delivery pipe, thereby cleaning the delivery pipe, filter 3, precision metering pump 4, and vaporization chamber 6; remove residual impurities, oil stains, and residual substances from previous operations from the delivery pipe, filter 3, precision metering pump 4, and vaporization chamber 6 with ultrapure water, and discharge the wastewater after cleaning through drain pump 9; in this step, the delivery pipe, filter 3, precision metering pump 4, and vaporization chamber 6 are cleaned twice with ultrapure water.

[0032] Step S2: Close the ultrapure water supply valve 2 in the cleaning module, and open the organic solvent supply valve 11, the front feed valve 5, the rear discharge valve 7, the drain pump valve 8, and the drain pump 9 to allow the ultrapure water in the organic solvent bottle 10 to flow into the delivery pipe, cleaning the delivery pipe, filter 3, precision metering pump 4, and vaporization chamber 6. After cleaning the delivery pipe, filter 3, precision metering pump 4, and vaporization chamber 6 twice with ultrapure water, clean them twice more with organic solvent to remove impurities and prevent the organic solvent to be vaporized from being contaminated or diluted by residues from previous operations. After cleaning, the waste solvent is discharged via the drain pump 9.

[0033] Step S3: Close the organic solvent supply valve 11, drain pump valve 8 and drain pump 9, and open the drying module, first valve 13 and exhaust valve to dry the conveying pipe, precision metering pump 4 and vaporization chamber 6. Hot air is introduced into the delivery pipe for drying to remove residual moisture and organic solvents in the pipe, thus preventing the gas purity from being affected by the mixing of media during the subsequent vaporization process. The waste gas generated during drying is discharged through the exhaust port.

[0034] Step S4: Close the drying module, the first valve 13 and the exhaust valve, and open the air inlet valve 15, the second valve 14 and the vacuum pump 16 to perform vacuuming on the pipeline and equipment between the organic solvent bottle 10 and the target gas cylinder 21. Once the preset vacuum level is reached, the inlet valve 15, the second valve 14, the vacuum pump 16, the front feed valve 5, and the rear discharge valve 7 are closed to maintain the vacuum level.

[0035] Step S5: Open the organic solvent supply valve 11 and the precision metering pump 4 to draw the preset dose of organic solvent to the front end of the vaporization chamber 6; the precision metering pump 4 accurately draws the organic solvent according to the preset dose, and the solvent flows through the filter 3 to intercept solid particles, suspended matter and other impurities in the solvent, so as to prevent impurities from entering the vaporization chamber 6 and affecting the vaporization effect or damaging the subsequent equipment. The filtered liquid is transported to the front buffer area of ​​the vaporization chamber 6.

[0036] Step S6: Open the front feed valve 5 to introduce the organic solvent temporarily stored at the front of the vaporization chamber 6 into the vaporization chamber 6. Then, close the front feed valve 5 and start the vaporization chamber 6 to convert the liquid organic solvent into a gaseous state. Inside the vaporization chamber 6, through the preset heating power and temperature control system, the trace amount of liquid organic reagent undergoes a rapid and uniform phase change and is converted into gas, ensuring uniform gas concentration.

[0037] Step S7: Open the inlet valve 15, the valve of the target gas cylinder 21, and the rear outlet valve 7 to allow the gaseous organic solvent to enter the target gas cylinder 21; and during this process, the MFC17 measures the gaseous organic solvent, and after reaching the preset dosage, close the inlet valve 15, the valve of the target gas cylinder 21, and the rear outlet valve 7.

[0038] Specifically, after step S1 is repeated twice, step S2 is executed twice.

[0039] In steps S1 and S2, the portion of the delivery pipe from MFC17 to the target gas cylinder 21 was not cleaned by ultrapure water and organic solvent. Therefore, before the gaseous organic solvent enters the target gas cylinder 21, the portion of the delivery pipe from MFC17 to the target gas cylinder 21 needs to be cleaned. Specifically, before step S7, the process includes: opening the rear discharge valve 7, exhaust valve 24, and inlet valve 15 to allow the gaseous organic solvent to be discharged through the exhaust pipe, thereby cleaning the delivery pipe between the rear discharge valve 7 and the target gas cylinder 21. After cleaning, the rear discharge valve 7 and exhaust valve 24 are closed, and the second valve 14 and vacuum pump 16 are reopened to perform vacuuming on the latter half of the pipeline. Then, the second valve 14 and vacuum pump 16 are closed, and step S7 is executed.

[0040] Specifically, in step S7, when the gaseous organic solvent enters the target gas cylinder 21, the thermometer 19 and the pressure gauge 20 monitor the temperature and pressure of the first branch pipe respectively. When the detected values ​​of the temperature and pressure of the first branch pipe exceed the preset upper limit, the built-in sensor in the MFC17 immediately triggers a signal transmission to the valve control system 18 to adjust the valve opening of the rear discharge valve 7.

[0041] This utility model has the following technical effects or advantages: (1) Through integrated and automated design, the following has been achieved: efficient operation, which simplifies the traditional cumbersome manual operation (such as weighing multiple times and changing needles), shortens the preparation time of each preparation, and lays the foundation for the rapid and batch development of standard substances; accurate measurement, which realizes the precise measurement of liquids and improves the accuracy and traceability of standard substances; and controllable process, which has a controllable vaporization function, which can accurately adjust the vaporization temperature, time and carrier gas flow rate to ensure that the organic solvent is completely and stably converted into a gaseous state, and avoids the problem of inaccurate concentration caused by uneven vaporization or local condensation.

[0042] (2) Improve operational safety by adopting a closed integrated design to minimize direct contact between personnel and toxic volatile reagents, thereby reducing health risks and meeting laboratory safety requirements.

[0043] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A gas mixing device for an organic gas standard substance, characterized in that: It includes a cleaning module, a drying module, an organic solvent bottle, a precision metering pump, a vaporization chamber, an MFC, a drain pump, a vacuum pump, a delivery pipe, a target gas cylinder, and a controller; Both the cleaning module and the organic solvent bottle are connected to the delivery pipe, and an organic solvent supply valve is also provided between the organic solvent bottle and the delivery pipe. The two ends of the conveying pipe are respectively equipped with a first valve and a second valve. The drying module is connected to the first valve, and the vacuum pump is connected to the second valve. Along the flow direction of the organic solvent, the precision metering pump, the vaporization chamber and the MFC are sequentially arranged on the conveying pipe, and the front end and the rear end of the vaporization chamber are respectively provided with a front feed valve and a rear discharge valve. The MFC is electrically connected to the back-end discharge valve for control. The target gas cylinder is connected to the end of the delivery pipe near the vacuum pump via a first branch pipe, and the first branch pipe is equipped with an inlet valve. The drainage pump is connected between the MFC and the rear discharge valve through a second branch pipe, and a drainage pump valve is provided on the second branch pipe. The cleaning module, drying module, precision metering pump, vaporization chamber, MFC, drain pump, vacuum pump, first valve, second valve, front feed valve, air inlet valve, and drain pump valve are all connected to the controller and controlled by the controller.

2. The gas mixing device for an organic gas standard substance according to claim 1, characterized in that: The cleaning module includes an ultrapure water bottle containing ultrapure water and an ultrapure water supply valve. The ultrapure water supply valve is connected to and controlled by the controller. The ultrapure water bottle is connected to the end of the delivery pipe near the first valve via a third branch pipe, and the ultrapure water supply valve is located on the third branch pipe.

3. The gas mixing device for an organic gas standard substance according to claim 1, characterized in that: It also includes a filter connected to the front end of the precision metering pump.

4. The gas mixing device for an organic gas standard substance according to claim 1, characterized in that: The drying module is a hot air blower.

5. The gas mixing device for an organic gas standard substance according to claim 1, characterized in that: The first branch pipe is also equipped with a thermometer and a pressure gauge, which are connected to the controller and controlled by the controller.

6. The gas mixing device for an organic gas standard substance according to claim 1, characterized in that: The delivery pipe is also connected to an exhaust pipe, which is further connected to an exhaust valve. The exhaust valve is connected to and controlled by the controller.

Images