Convection heating type gas diluting and distributing device

Abstract

The utility model belongs to the field and provides a convection heating type gas diluting and distributing device which comprises a columnar container with an opening in the upper portion and a telescopic gas bag detachably arranged at the opening in a sealed mode, and the columnar container and the telescopic gas bag are the same in volume. The outer wall of the columnar container is covered with a temperature control assembly, and the columnar container is provided with a diluent gas inlet, a waste gas outlet and a standard gas outlet which are communicated with the interior of the columnar container. The convection heating type gas diluting and distributing device provided by the utility model is simple in structure and convenient to use, a gas standard sample can be prepared by heating a liquid standard sample in a diluting manner, and meanwhile, the sample is quantified by virtue of a mass spectrometer, so that the distribution loss caused by adsorption and deposition of semi-volatile substances or active substances in the distribution process is avoided; and the gas distribution stability and reliability are improved.

Description

Technical Field

[0001] This utility model belongs to the technical field of experimental gas mixing equipment, and specifically relates to a convection heating gas dilution and mixing device for quantitative gas mixing of substances such as semi-volatile substances or active substances that are difficult to prepare standard gases. Background Technology

[0002] Existing standard gas mixing methods mainly include static and dynamic methods. Commonly used static methods include gas cylinder mixing, syringe mixing, and plastic bag mixing. However, these methods suffer from adsorption phenomena on the inner walls of gas cylinders or plastic containers, or reactions between the container's inner wall material and the active sample substance. This leads to changes in the gas composition inside the cylinder over long periods, resulting in a lower concentration than the actual value. Furthermore, preparing standard gases of different concentrations or compositions requires a large number of gas cylinders, occupying significant laboratory space and hindering the smooth and orderly conduct of the experiment. Meanwhile, dynamic gas mixing methods have higher technical requirements. For example, permeation tube type standard gas generators, while overcoming some of the shortcomings of static methods, are technically challenging. They require extremely high precision in controlling and measuring the flow rates of the source and diluent gases; even minor fluctuations can affect the accuracy of the mixing. Additionally, they require complex equipment to precisely control parameters such as temperature, pressure, and flow rate, increasing the cost of gas mixing experiments. Meanwhile, during the detection of a specific component in a multi-component sample, environmental factors such as temperature, humidity, or other components can interfere with the target component. How to eliminate the interference of environmental factors during gas mixing is also an urgent problem to be solved.

[0003] Therefore, there is a need to design a convection heating gas dilution and distribution device that can effectively solve at least some of the above-mentioned problems and defects. Summary of the Invention

[0004] To solve the above technical problems, this utility model proposes a convection heating gas dilution and mixing device. It has a simple structure and is easy to use. It can dilute and mix gas standard samples by heating liquid standard samples, and simultaneously use mass spectrometry to quantify the samples. This avoids gas mixing losses caused by the adsorption and deposition of semi-volatile or active substances during the gas mixing process, thereby improving the stability and reliability of gas mixing.

[0005] The technical solution of this utility model is:

[0006] This utility model proposes a convection heating gas dilution and distribution device, characterized in that: it includes a cylindrical container with an opening at the top and a removable telescopic gas bag sealed at the opening, wherein the cylindrical container and the telescopic gas bag have the same volume.

[0007] The outer wall of the cylindrical container is covered with a temperature control component, and the cylindrical container is provided with a dilution gas inlet, an exhaust gas outlet, and a standard gas outlet that are connected to its interior.

[0008] Preferably, the convection heating gas dilution and gas distribution device provided by this utility model further includes a stirring assembly, which includes a rotatable magnetic rotor fan disposed at the bottom of the inner columnar container and a magnetic stirrer disposed at the bottom of the outer columnar container.

[0009] Preferably, the convection heating gas dilution and gas distribution device provided by this utility model further includes a humidity regulating component. The columnar container is also provided with a humidity inlet communicating with its interior. The humidity regulating component includes a humidity generator communicating with the humidity inlet via a pipeline and a humidity inlet valve provided on the pipeline.

[0010] Preferably, the convection heating gas dilution and distribution device provided by this utility model further includes a dilution gas cylinder connected to the dilution gas inlet via a pipeline, and a dilution gas inlet valve disposed on the pipeline.

[0011] Preferably, the convection heating gas dilution and distribution device provided by this utility model further includes a waste gas extraction pump connected to the waste gas outlet via a pipeline, and a waste gas outlet valve installed on the pipeline.

[0012] Preferably, the convection heating gas dilution and mixing device provided by this utility model further includes a mass spectrometer connected to the standard gas outlet via a pipeline, and a standard gas outlet valve installed on the pipeline.

[0013] Preferably, the cylindrical container is a passivated stainless steel cylindrical container, the telescopic air bag is a Teflon soft air bag, and the pipeline is a passivated stainless steel pipeline.

[0014] Preferably, the convection heating gas dilution and mixing device provided by this utility model further includes a micro-injector, and the telescopic gas bag is provided with an interface valve connected to its interior. The micro-injector is connected to the cylindrical container and the interior of the telescopic gas bag through the interface valve.

[0015] This utility model has the following advantages and effects compared with the prior art:

[0016] The convection heating gas dilution and mixing device provided by this utility model overcomes the problems of unstable gas concentration values ​​caused by the easy adsorption or deposition of semi-volatile substances during the standard gas mixing process in the prior art, as well as the short lifespan of active substances and easy loss after a period of mixing. At the same time, it overcomes the problem that different gas cylinders or custom-made permeation tubes of different components are needed during the gas mixing process of multi-component samples, which makes it difficult to meet the quantitative detection needs of standard gases under different environments and working conditions.

[0017] The convection heating gas dilution and mixing device provided by this utility model directly uses liquid standard samples or self-prepared liquid standard samples of different concentrations for gas mixing. By heating the liquid standard sample of known concentration to make it volatilize and diffuse, standard gas samples at the ppb to ppm level can be prepared. The temperature control component wrapped on the outer wall of the columnar container promotes the volatilization of the liquid standard sample and reduces condensation and adsorption through heating. The stirring component equipped with a magnetic rotor fan promotes uniform gas convection mixing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the convection heating gas dilution and distribution device in an embodiment of this utility model;

[0019] Figure 2 This is another structural schematic diagram of the convection heating gas dilution and gas distribution device in this embodiment of the present invention.

[0020] Reference numerals: 1. Telescopic gas bag; 2. Cylindrical container; 3. Standard gas outlet; 4. Standard gas outlet valve; 5. Mass spectrometer; 6. Temperature control component; 7. Humidity generator; 8. Humidity inlet; 9. Magnetic rotor fan; 10. Magnetic stirrer; 11. Dilute gas inlet; 12. Exhaust gas outlet; 13. Dilute gas cylinder; 14. Exhaust gas pump; 15. Piping; 16. Micro-syringe; 17. Humidity inlet valve; 18. Dilute gas inlet valve; 19. Exhaust gas outlet valve. Detailed Implementation

[0021] To enable those skilled in the art to better understand this utility model, it will now be further described in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of this utility model.

[0022] Example:

[0023] like Figures 1-2 As shown, this utility model provides a convection heating gas dilution and distribution device, which includes a cylindrical container 2 with an opening at the top and a removable telescopic gas bag 1 sealed at the opening. The cylindrical container 2 and the telescopic gas bag 1 have the same volume, so that the gas in the container can be completely discharged during the pumping and cleaning process.

[0024] Specifically, the cylindrical container 2 is a passivated stainless steel cylindrical container with passivated and smoothed inner walls, and the telescopic air bag 1 is a Teflon soft air bag, which is soft and tough. When evacuating the cylindrical container 2, the air pressure inside the cylindrical container 2 can always remain consistent with the atmospheric pressure, so that the air pressure and flow rate are stable. At the same time, the Teflon material surface is not easy to adhere and has stable chemical properties, thereby avoiding the adsorption of semi-volatile substances or the reaction with active substances. In addition, the telescopic air bag 1 is equipped with a sealed interface valve connected to its interior. Since the air bag interface valve is a mature existing technology, its specific structure and principle will not be described here.

[0025] The outer wall of the columnar container 2 is covered with a temperature control component 6. The columnar container 2 is equipped with a dilution gas inlet 11, an exhaust gas outlet 12, a standard gas outlet 3, and a humidity inlet 8, all of which are connected to its interior. The columnar container 2 is connected to an external dilution gas cylinder 13 via the dilution gas inlet, to an external exhaust gas pump 14 via the exhaust gas outlet 12, to an external mass spectrometer 5 via the standard gas outlet 3, and to an external humidity generator 7 via the humidity inlet 8. Specifically, the temperature control component 6 includes a connected electric heating element and a temperature sensor to heat and regulate the temperature of the columnar container 2, thereby promoting the accelerated evaporation of semi-volatile or non-volatile substances and reducing the condensation and adsorption of sample substances. It should be noted that the electric heating element and the temperature sensor are mature existing technologies in this field, and their specific structures will not be described in detail here.

[0026] Furthermore, the convection heating gas dilution and mixing device in this embodiment also includes a dilution gas cylinder 13 connected to the dilution gas inlet 11 via a pipeline 15, and a dilution gas inlet valve 18 installed on the pipeline 15. The dilution gas inlet 11 is connected to a carrier gas dilution gas source such as zero air. It should be noted that for the dilution of active substances, other inert gases such as nitrogen can also be used. Specifically, the pipeline 15 is a stainless steel pipeline with passivated and smoothed inner walls, and the dilution gas inlet valve 18 is a stainless steel ball valve with passivated and smoothed inner walls. The dilution gas inlet valve 18 controls the inlet volume to dilute the sample in the columnar container 2.

[0027] Furthermore, the convection heating gas dilution and distribution device in this embodiment also includes a waste gas extraction pump 14 connected to the waste gas outlet 12 via a pipeline 15, and a waste gas outlet valve 19 installed on the pipeline 15. The waste gas outlet 12 is connected to the extraction pump via the pipeline 15, and the opening and closing of the pipeline 15 is controlled by the waste gas outlet valve 19. By controlling the alternating opening and closing of the dilution gas inlet valve 18 and the waste gas outlet valve 19, the function of cleaning the columnar container 2 is achieved. Specifically, the pipeline 15 is a stainless steel pipeline with passivation and smoothing treatment on the inner wall, and the waste gas outlet valve 19 is a stainless steel ball valve with passivation and smoothing treatment on the inner wall.

[0028] Furthermore, the convection heating gas dilution and mixing device in this embodiment also includes a mass spectrometer 5 connected to the standard gas outlet 3 via a pipeline 15, and a standard gas outlet valve 4 installed on the pipeline 15. That is, the standard gas outlet 3 of the columnar container 2 is directly connected to the inlet gas path of the mass spectrometer 5 via the pipeline 15 and the standard gas outlet valve 4. The columnar container 2 is sealed to the telescopic gas bag 1. When the mass spectrometer 5 draws in gas under negative pressure, the telescopic gas bag 1 is compressed, ensuring that the gas pressure inside the columnar container 2 is always balanced with atmospheric pressure, thereby guaranteeing a stable self-aspiration gas flow rate of the mass spectrometer 5. Specifically, the pipeline 15 is a stainless steel pipeline with passivated and smoothed inner walls, and the standard gas outlet valve 4 is a stainless steel ball valve with passivated and smoothed inner walls.

[0029] Furthermore, the convection heating gas dilution and distribution device in this embodiment also includes a humidity regulating component. The cylindrical container 2 is also provided with a humidity inlet 8 connected to its interior. The humidity regulating component includes a humidity generator 7 connected to the humidity inlet 8 via a pipeline 15, and a humidity inlet valve 17 disposed on the pipeline 15. Specifically, the pipeline 15 is a stainless steel pipeline with passivated and smoothed inner walls, and the humidity inlet valve 17 is a stainless steel ball valve with passivated and smoothed inner walls. The humidity environment inside the cylindrical container 2 can be changed and adjusted by opening and closing the humidity generator 7 and the humidity inlet valve 17.

[0030] Furthermore, the convection heating gas dilution and mixing device in this embodiment also includes a micro-injector 16. The telescopic gas bag 1 is provided with an interface valve that communicates with its interior. The micro-injector 16 is connected to the cylindrical container 2 and the interior of the telescopic gas bag 1 through the interface valve, so as to inject a liquid standard sample of known concentration or other environmental interference substances into the cylindrical container 2 through the micro-injector 16.

[0031] Furthermore, the convection heating gas dilution and mixing device in this embodiment also includes a stirring assembly, which includes a rotatable magnetic rotor fan 9 disposed at the bottom of the cylindrical container 2 and a magnetic stirrer 10 disposed at the bottom of the outer side of the cylindrical container 2. Specifically, the magnetic rotor fan 9 consists of fan blades, a magnetic rotor, and ball bearings. The magnetic rotor fan 9 is driven to rotate by the magnetic stirrer 10 below the cylindrical container 2, thereby providing power to the internal magnetic rotor fan 9 without contact, allowing the gas inside the cylindrical container 2 to fully convect and mix evenly, without needing to consider sealing issues. It should be noted that the magnetic rotor fan 9 and the magnetic stirrer 10 are both mature existing technologies in the field, and their specific structures and principles will not be described in detail here. At the same time, the surface of the magnetic rotor fan 9 located at the bottom of the cylindrical container 2 is passivated and smoothed to reduce the loss caused by the adsorption and reaction of semi-volatile or active substances.

[0032] In actual use:

[0033] The above-mentioned convection heating gas dilution and mixing device needs to be cleaned after use or before the next gas mixing. The specific cleaning operation steps are as follows: First, close the standard gas outlet valve 4, humidity inlet valve 17, and dilution gas inlet valve 18. Turn on the waste gas pump 14 and open the waste gas outlet valve 19 directly connected to the waste gas pump 14. Since the telescopic gas bag 1 can be compressed to the bottom of the cylindrical container 2, and the telescopic gas bag 1 and the cylindrical container 2 have the same volume, all the gas in the cylindrical container 2 can be extracted. Close the waste gas outlet valve 19, open the dilution gas inlet valve 18, open the dilution gas cylinder 13, and introduce dilution gas into the cylindrical container 2. Wait for the telescopic gas to fully inflate, and then close the dilution gas inlet valve 18. Repeat the above operation 3 to 4 times to complete the cleaning. It can be seen that the gas mixing device in this embodiment is convenient and quick to clean and use, inexpensive, and can realize the on-site preparation and use of gas samples.

[0034] When using the above-mentioned convection-heated gas dilution and mixing device for gas mixing and when using the mass spectrometer 5 for mechanical energy quantitative calibration, the following operations are required: After cleaning the columnar container 2, open the dilution gas inlet valve 18 and the dilution gas cylinder 13, and flush the dilution gas into the columnar container 2. The retractable gas bag 1 will inflate as the dilution gas is flushed in, and the degree of inflation of the retractable gas bag 1 should be approximately equal to the opening at the top of the columnar container 2. (Reference) Figure 2As shown, close the dilution gas inlet valve 18; use a micro-syringe 16 to extract a standard liquid sample of a certain concentration and inject it into the columnar container 2 through the interface valve of the telescopic gas bag 1. The liquid sample in the columnar container 2 is heated by the temperature control component 6 to evaporate, and the gas inside the columnar container 2 is mixed evenly by the gas convection generated by the magnetic rotor fan 9. Since the volume of the columnar container 2 is known and the amount of liquid standard sample injected by the micro-syringe 16 is known, the gas concentration of the sample in the gas mixing device can be calculated by the ideal gas law; open the standard gas outlet valve 4 and use the mass spectrometer 5 for quantitative detection.

[0035] Furthermore, when detecting the sensitivity of a certain component in human breath, since human breath is complex in composition and has a high water vapor content and humidity, in order to simulate the detection sensitivity of the sample substance under different environments, other sample substances can be added simultaneously using a micro-syringe 16, the temperature control component 6 can be used to control the temperature inside the column container 2, and the humidity generator 7 can be used to add and control the humidity inside the column container 2, so as to meet the detection sensitivity of a specific component of the mass spectrometer 5 under different operating conditions.

[0036] The above-mentioned convection heating gas dilution and gas distribution device can also be used to collect and detect volatile substances released from plants, household items, furniture and other items. The specific operating steps are as follows: Remove the telescopic gas bag 1 above the columnar container 2, put the item to be tested into the inside of the columnar container 2, install the telescopic gas bag 1 and seal it, start the temperature control component 6 and humidity generator 7 to adjust and control the environmental factors inside the columnar container 2, so as to simulate the types of substances to be tested and their volatilization release concentrations under different working conditions.

[0037] In summary, the convection heating gas dilution and mixing device provided by this utility model has a simple structure and is easy to use. It can dilute and mix gas standard samples by heating liquid standard samples, and simultaneously use mass spectrometry to quantify the samples. This avoids gas mixing losses caused by the adsorption and deposition of semi-volatile or active substances during the gas mixing process, thereby improving the stability and reliability of gas mixing.

[0038] The above are merely preferred embodiments of the present utility model and do not limit the patent scope of the present utility model. All equivalent changes and modifications made within the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A convection heated gas dilution gas distribution device, characterized by: The application relates to a cylindrical container (2) with an upper opening, and a detachable sealing flexible air bag (1) arranged at the opening, wherein the volume of the cylindrical container (2) is the same as that of the flexible air bag (1). The outer wall of the cylindrical container (2) is covered with a temperature control assembly (6), and the cylindrical container (2) is provided with a dilution gas inlet (11), a waste gas outlet (12) and a standard gas outlet (3) which are in communication with the inside of the cylindrical container (2).

2. The convection heated gas dilution gas distribution device of claim 1, wherein: The application further comprises a stirring assembly, which comprises a magnetic rotor fan (9) rotatably arranged at the bottom of the cylindrical container (2), and a magnetic stirrer (10) arranged at the bottom of the cylindrical container (2).

3. The convection heated gas dilution gas distribution device of claim 1, wherein: The application further comprises a humidity adjusting assembly, and the cylindrical container (2) is further provided with a humidity inlet (8) in communication with the inside of the cylindrical container (2), wherein the humidity adjusting assembly comprises a humidity generator (7) connected to the humidity inlet (8) through a pipeline (15), and a humidity inlet valve (17) arranged on the pipeline (15).

4. The convective heating gas dilution gas distribution device of claim 1, wherein: The application further comprises a dilution gas cylinder (13) connected to the dilution gas inlet (11) through a pipeline (15), and a dilution gas inlet valve (18) arranged on the pipeline (15).

5. The convective heating gas dilution gas distribution device of claim 1, wherein: The application further comprises a waste gas exhaust pump (14) connected to the waste gas outlet (12) through a pipeline (15), and a waste gas outlet valve (19) arranged on the pipeline (15).

6. The convective heating gas dilution gas distribution device of claim 1, wherein: The application further comprises a mass spectrometer (5) connected to the standard gas outlet (3) through a pipeline (15), and a standard gas outlet valve (4) arranged on the pipeline (15).

7. The convective heating gas dilution gas distribution device of any one of claims 3-6, wherein: The cylindrical container (2) is a passivated stainless steel cylindrical container, the flexible air bag (1) is a soft Teflon air bag, and the pipeline (15) is a passivated stainless steel pipeline.

8. The convective heating gas dilution gas distribution device of claim 1, wherein: The application further comprises a microsyringe (16), and the flexible air bag (1) is provided with an interface valve in communication with the inside of the flexible air bag (1), wherein the microsyringe (16) is connected to the inside of the cylindrical container (2) and the flexible air bag (1) through the interface valve.

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