Chemical gas monitoring device

Abstract

The utility model provides a chemical gas monitoring devices belongs to gas monitoring technical field. Including gas monitor, the top of gas monitor is fixed with the gas chamber, the top of gas chamber is fixed with the air inlet pipe, the bottom side surface of gas chamber is equipped with the exhaust hole, the inside bottom surface middle part of gas chamber is fixed with the sensor, the lower port of air inlet pipe is connected with the dry pipe that reaches the sensor place vertically, the middle section of dry pipe is provided with the selective permeation part, and the inside bottom of gas chamber is provided with the reflux cylinder that surrounds the selective permeate part and sensor, forms the reflux channel between the reflux cylinder and dry pipe, makes the airflow in dry pipe pass through the sensor place after the lower end, along the reflux channel and against the outside surface of selective permeation part flow, finally discharges from the exhaust hole. The utility model not only realized efficient, maintenance -free, no consumable drying pretreatment, but also significantly optimized the flow field distribution of sensor detection surface, and the overall use effect is good, and the reliability is high.

Description

Technical Field

[0001] This utility model relates to the field of gas monitoring technology, and in particular to a chemical gas monitoring device. Background Technology

[0002] In the field of chemical gas monitoring, especially for sensors based on electrochemical and catalytic combustion principles, ambient humidity is a key factor affecting their measurement accuracy, stability, and lifespan. High humidity environments can lead to dilution of the sensor electrolyte, degradation of the performance of sensitive materials, reading drift, and even permanent damage.

[0003] Currently, existing technologies typically pre-treat the sampled gas by adding a drying tube in front of the sensor. While common desiccants such as silica gel and activated carbon can effectively dehumidify, they irreversibly adsorb the target gas, causing severe distortion of the monitored concentration. Furthermore, they require frequent replacement, resulting in high maintenance costs. Another solution is to use semiconductor refrigeration for dehumidification, but this method is complex, consumes a lot of power, and is expensive, making it unsuitable for portable or low-power devices.

[0004] In addition, traditional air chambers have simple structures, mostly straight cavities, with chaotic airflow organization, which easily generates eddies and dead zones. This results in uneven gas contact with the sensor's sensitive surface, further reducing response speed and measurement accuracy.

[0005] Therefore, this application provides a chemical gas monitoring device to solve the above-mentioned technical problems. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a chemical gas monitoring device to solve the problems of existing drying technology, such as adsorption of target gas leading to measurement distortion, frequent maintenance, and uneven airflow organization in the gas chamber leading to low detection efficiency.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution: A chemical gas monitoring device includes a gas monitor. A gas chamber is fixed to the top of the gas monitor, and an inlet pipe is fixed to the top of the gas chamber. An exhaust port is provided on the bottom side of the gas chamber. A sensor is fixed to the middle of the bottom surface of the gas chamber. A drying tube extending vertically to the sensor is connected to the lower end of the inlet pipe. A selective permeation section is provided in the middle section of the drying tube. A reflux cylinder surrounding the selective permeation section and the sensor is provided at the bottom of the gas chamber. A reflux channel is formed between the reflux cylinder and the drying tube, so that the airflow in the drying tube flows through the sensor at the lower end, flows along the reflux channel and against the outer surface of the selective permeation section, and finally exits from the exhaust port.

[0008] Optionally, the surface of the gas monitor is provided with a display screen and control buttons.

[0009] Optionally, the selective permeation section includes a perfluorosulfonic acid membrane disposed in the middle of the drying tube.

[0010] Optionally, a sampling pump is fixed to the lower end of the drying tube, the air inlet of the sampling pump is connected to the lower port of the drying tube, and the air outlet of the sampling pump faces the sensor.

[0011] Optionally, the outlet of the sampling pump is fixed with a speed-reducing and equalizing cylinder.

[0012] Optionally, the top of the deceleration equalization cylinder is fixed with an installation pipe installed at the air outlet of the sampling pump, and the bottom of the deceleration equalization cylinder is a flat flow equalization plate with several flow equalization holes.

[0013] Optionally, the lower surface of the flow equalization plate is parallel to the upper surface of the sensor.

[0014] Compared with the prior art, this utility model has at least the following beneficial effects: In the above scheme, through the cooperation of the drying tube, its internal selective permeation section, and the reflux channel formed together with the reflux cylinder, the dried exhaust gas after detection can be used as a purge gas, flowing countercurrently through the outer surface of the selective permeation section, thereby establishing and maintaining a high concentration difference between the inside and outside of the membrane. This achieves selective drying that efficiently removes water molecules without adsorbing the target gas, ensuring the drying chamber through which airflow passes in the drying tube, thus fundamentally ensuring the accuracy of monitoring data and extending the life of the sensor. In the above scheme, the deceleration and equalization cylinder connected to the outlet of the sampling pump and the bottom flow-dividing hole, together with the constraint and guidance of the return cylinder, can reduce the pulse airflow into a uniform and stable laminar flow, and make it vertically and uniformly cover the entire sensitive surface of the sensor, eliminating detection dead zones and eddies, and achieving the effect of improving the sensor response speed and reading stability.

[0015] In summary, this device not only achieves efficient, maintenance-free, and consumable-free drying pretreatment, but also significantly optimizes the flow field distribution on the sensor detection surface, resulting in good overall performance and high reliability. Attached Figure Description

[0016] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the present invention and, together with the specification, further serve to explain the principles of the present invention and enable those skilled in the art to implement and use the present invention.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the internal structure of the air chamber of this utility model.

[0019] Figure 3 For the present utility model Figure 2 An enlarged schematic diagram of the structure at point A in the middle.

[0020] Figure 4 This is a cross-sectional view of the deceleration and equalization cylinder of this utility model.

[0021] [Figure Labels] 1. Gas monitor; 101. Display screen; 102. Control button; 2. Gas chamber; 201. Exhaust port; 3. Inlet pipe; 4. Drying pipe; 5. Selective permeation section; 6. Sampling pump; 7. Deceleration and equalization cylinder; 701. Mounting pipe; 702. Diversion hole; 8. Sensor; 9. Return cylinder; 10. Return channel. Detailed Implementation

[0022] The chemical gas monitoring device provided by this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit this utility model.

[0023] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0024] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0025] It is understood that the meanings of “on”, “above”, and “above” in this utility model should be interpreted in the broadest manner, such that “on” not only means “directly on” something, but also includes the meaning of being “on” something with an intervening feature or layer, and that “above” or “above” not only means “on” something, but also includes the meaning of being “on” something without an intervening feature or layer.

[0026] Furthermore, spatially related terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein for convenience to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the accompanying drawings. Spatially related terms are intended to cover different orientations in the use or operation of the device other than those depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially related descriptive terms used herein can be interpreted similarly.

[0027] like Figure 1-4 As shown, this embodiment of the present invention provides a chemical gas monitoring device, including a gas monitor 1, which integrates existing chemical gas monitoring components such as a main control circuit board, a battery, and a signal processing unit (details omitted). A display screen 101 and control buttons 102 are provided on its surface for human-machine interaction. A cylindrical gas chamber 2 is fixed to the top of the gas monitor 1 by threads or clips. An air inlet pipe 3 is fixedly connected to the top side wall of the gas chamber 2 as the main inlet for the external gas to be measured. An exhaust port 201 is provided on the bottom side of the gas chamber 2 for the final discharge of all waste gas. A core sensor 8 is fixedly installed in the center of the inner bottom surface of the gas chamber 2 through a standard interface. The upper surface of its sensitive element is typically a planar structure.

[0028] A vertically extending drying tube 4 is connected to the lower end of the intake pipe 3. This drying tube 4 is made of a chemically inert material, and its lower end extends to a position close to the upper surface of the sensor 8 located in the middle of the bottom surface of the air chamber 2. The middle section of the drying tube 4 is provided with a selective permeation section 5, which is composed of a section of perfluorosulfonic acid membrane material (such as Nafion tube). Its two ends are connected to the upper and lower sections of the drying tube 4 by interference fit or special sealant to ensure airtightness. An inverted cup-shaped reflux cylinder 9 is fixedly installed at the bottom of the air chamber 2. The upper edge of the reflux cylinder 9 is located between the selective permeation section 5 and the exhaust port 201, and its lower opening surrounds the base of the sensor 8, thereby forming an annular reflux channel 10 between the inner wall of the reflux cylinder 9 and the outer wall of the drying tube 4.

[0029] The working airflow path is as follows: external gas enters through the inlet pipe 3, flows directly into the drying tube 4, and flows downwards. When flowing through the selective permeation section 5, water molecules permeate outwards through the membrane wall driven by the concentration difference. The dried gas continues downwards and flows out from the lower port of the drying tube 4. A miniature sampling pump 6 is fixedly installed at the lower port of the drying tube 4 via a flange structure, with its inlet connected to the lower port of the drying tube 4 to provide the power for gas flow. The outlet of the sampling pump 6 faces vertically downwards towards the sensor 8.

[0030] To optimize airflow, a deceleration and equalization cylinder 7 is threadedly installed at the outlet of the sampling pump 6. The top of the deceleration and equalization cylinder 7 has an installation pipe 701 connected to the outlet of the sampling pump 6, and its bottom is a flat flow equalization plate (not shown in the figure). The flow equalization plate is evenly distributed with several small flow-dividing holes 702, and the lower surface of the flow equalization plate is parallel to the upper surface of the sensor 8. The pulsed airflow from the outlet of the sampling pump 6 is fully diffused and decelerated after passing through the flow-dividing holes 702, forming a uniform and stable laminar flow that vertically and uniformly covers the entire sensitive surface of the sensor 8.

[0031] After testing, the dried gas, constrained and guided by the return tube 9, flows upwards around the sensor 8 into the return channel 10. This gas, now dried exhaust gas, flows upwards within the return channel 10, opposite to the downward flow of humidified gas in the drying tube 4, thus flowing against the outer surface of the selective permeation section 5. This counter-current flow provides a continuous and dry purge gas to the outside of the membrane, efficiently carrying away permeated water molecules from the membrane surface, thereby establishing and maintaining the maximum water vapor concentration difference between the inside and outside of the membrane, significantly improving drying efficiency.

[0032] Finally, the purge gas carrying moisture merges with a small amount of gas that may have seeped in, and together they are discharged from the system through the exhaust port 201 on the bottom side of the gas chamber 2, completing the entire self-circulating drying and detection process. This structure ingeniously integrates drying and detection, naturally forming an efficient, energy-saving, and reliable gas pretreatment and monitoring solution through its physical construction.

[0033] Furthermore, it should be noted that during the initial startup of the aforementioned self-circulating drying system, because a concentration difference has not yet been established inside and outside the membrane, a brief airflow may come into contact with the sensor without sufficient drying. However, thanks to the stable flow rate provided by the sampling pump 6 and the compact flow channel structure defined by the return tube 9, the system can quickly form a strong positive feedback effect by relying on the waste gas recirculation. An effective concentration difference can typically be established within tens of seconds, and the system enters a highly efficient drying state. This initial stage is extremely short, and the impact of the brief contact with moisture on sensor performance and lifespan is negligible, far superior to the damage caused by long-term exposure to high humidity environments. For applications with extremely high requirements, in other embodiments, this can be further mitigated by adding simple structures such as a startup exhaust valve, but the core structure of this invention is sufficient to meet the reliability and accuracy requirements under most operating conditions.

[0034] This utility model encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this utility model. To provide the public with a thorough understanding of this utility model, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand this utility model even without these detailed descriptions. Furthermore, to avoid unnecessary confusion regarding the essence of this utility model, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0035] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A chemical gas monitoring device, comprising a gas monitor (1), wherein a gas chamber (2) is fixed to the top of the gas monitor (1), an inlet pipe (3) is fixed to the top of the gas chamber (2), and an exhaust port (201) is provided on the bottom side of the gas chamber (2), characterized in that, A sensor (8) is fixed in the middle of the bottom surface of the air chamber (2). The lower end of the air inlet pipe (3) is connected to a drying pipe (4) that extends vertically to the sensor (8). A selective permeation section (5) is provided in the middle section of the drying pipe (4). A return cylinder (9) is provided at the bottom of the air chamber (2) that surrounds the selective permeation section (5) and the sensor (8). A return channel (10) is formed between the return cylinder (9) and the drying pipe (4). The airflow in the drying pipe (4) flows through the sensor (8) at the lower end, then flows along the return channel (10) and against the outer surface of the selective permeation section (5), and finally exits from the exhaust port (201).

2. The chemical gas monitoring apparatus according to claim 1, wherein The surface of the gas monitor (1) is provided with a display screen (101) and control buttons (102).

3. The chemical gas monitoring apparatus according to claim 1, wherein The selective permeation section (5) includes a perfluorosulfonic acid membrane material disposed in the middle of the drying tube (4).

4. The chemical gas monitoring device according to claim 1, characterized in that, A sampling pump (6) is fixed at the lower end of the drying tube (4). The air inlet of the sampling pump (6) is connected to the lower port of the drying tube (4), and the air outlet of the sampling pump (6) faces the sensor (8).

5. The chemical gas monitoring device according to claim 4, characterized in that, The outlet of the sampling pump (6) is fixed with a speed-reducing equalization cylinder (7).

6. The chemical gas monitoring apparatus according to claim 5, wherein The top of the deceleration equalization cylinder (7) is fixed with an installation pipe (701) installed at the outlet of the sampling pump (6), and the bottom of the deceleration equalization cylinder (7) is a flat flow equalization plate, and a number of flow equalization holes (702) are opened on the flow equalization plate.

7. The chemical gas monitoring apparatus according to claim 6, wherein The lower surface of the flow equalization plate is parallel to the upper surface of the sensor (8).

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