Gas path structure for detecting trace oxygen by electrochemical method

Abstract

The utility model relates to a gas path structure for detecting trace oxygen through an electrochemical method, and relates to the field of environment ultralow-content oxygen detection, and the gas path structure for detecting trace oxygen through the electrochemical method comprises a gas inlet pipe, an exhaust pipe, a main gas path pipe, a sensor body, a protective gas path pipe and a control part; the air inlet pipe and the exhaust pipe fixedly communicate with the two ends of the main air path pipe correspondingly. The sensor body is mounted on the main gas path pipe; two ends of the protective gas path pipe are fixedly communicated with the main gas path pipe respectively; the joints of the gas inlet pipe, the main gas path pipe and the protective gas path pipe and the joints of the exhaust pipe, the main gas path pipe and the protective gas path pipe are fixedly communicated through three-way valves; the control piece is installed on the main gas path pipe and located at the end, close to the gas inlet pipe, of the main gas path pipe, and the control piece is used for controlling whether gas paths of the gas inlet pipe and the sensor body are communicated or not. According to the invention, the electrolyte of the sensor can be prevented from being quickly exhausted due to long-time exposure to high-concentration oxygen, and the service life of the sensor is prolonged.

Description

Technical Field

[0001] This application relates to the field of detecting ultra-low oxygen content in the environment, and particularly to a gas path structure for detecting trace oxygen by an electrochemical method. Background Art

[0002] The analytical methods for trace oxygen mainly include colorimetry, chemical battery method, yellow phosphorus luminescence method, concentration cell method, and gas chromatography. Each detection method has its own advantages and disadvantages. The electrochemical sensor developed based on the chemical battery method has the advantages of low cost, small size, low power consumption, and simple use, and is the most widely used in industrial, laboratory and other fields.

[0003] Electrochemical sensing generally consists of four components: a membrane, an electrolyte, a lead anode, and a cathode. When oxygen contacts the sensor, it passes through the membrane and reacts with the electrolyte to generate an electric current. The current is processed by a signal conditioning and conversion circuit, and finally the information related to the gas concentration is converted into a voltage signal, so as to realize the detection, monitoring, analysis and alarm of the gas concentration.

[0004] The purpose of the electrochemical trace oxygen instrument is to measure the micro content of oxygen in other gases, but the external environment where the instrument is located is air. The oxygen content in the air is about 210,000 PPM. Compared with the measuring range of the sensor, the oxygen content in the air is extremely high. Therefore, the trace oxygen electrochemical sensor cannot be directly exposed to the air, otherwise the electrolyte of the sensor is easily exhausted. Therefore, the sensor chamber must be isolated from the air. The currently commonly used isolation method is to use a mechanical four-way valve. When the instrument is not measuring and is in the air, the mechanical four-way valve is switched to the bypass gas path, and the trace oxygen chamber and the sensor are isolated from the air; when measuring, the mechanical four-way valve is switched to the measuring gas path, and the sample gas flows through the chamber and contacts the sensor. In actual use, the mechanical four-way valve needs to be manually operated on-site, and sometimes it is forgotten to be closed when not measuring, resulting in air entering the chamber. When measuring again, the oxygen concentration cannot drop to the theoretical value in a short time, and the electrolyte of the oxygen sensor is extremely easy to be exhausted. Summary of the Invention

[0005] In order to effectively isolate the sensor from its high oxygen content (about 210,000 PPM in the air) environment to prevent the sensor electrolyte from being quickly exhausted due to exposure to high-concentration oxygen, this application provides a gas path structure for detecting trace oxygen by an electrochemical method.

[0006] The gas path structure for detecting trace oxygen by an electrochemical method provided by this application adopts the following technical solution:

[0007] A gas path structure for detecting trace oxygen by an electrochemical method includes an inlet pipe, an exhaust pipe, a main gas path pipe, a sensor body, a protective gas path pipe, and a control member;

[0008] The intake pipe and the exhaust pipe are respectively fixedly connected and communicated with both ends of the main gas pipeline;

[0009] The sensor body is installed on the main gas pipeline;

[0010] Both ends of the protective gas pipeline are respectively fixedly connected and communicated with the main gas pipeline;

[0011] The joints of the intake pipe, the main gas pipeline and the protective gas pipeline, and the joints of the exhaust pipe, the main gas pipeline and the protective gas pipeline are all fixedly connected and communicated by three-way valves;

[0012] The control member is installed on the main gas pipeline and is located at one end of the main gas pipeline close to the intake pipe. The control member is used to control whether the gas path between the intake pipe and the sensor body is conducted.

[0013] Optionally, the control member includes a first solenoid valve, and the first solenoid valve is fixedly connected and communicated with the main gas pipeline.

[0014] Optionally, the gas path structure further includes a second solenoid valve. The second solenoid valve is located at one end of the main gas pipeline close to the exhaust pipe. The second solenoid valve is fixedly connected and communicated with the main gas pipeline. The second solenoid valve is used to prevent the gas in the main gas pipeline from flowing back.

[0015] Optionally, the protective gas pipeline is arranged in a spiral shape.

[0016] Optionally, a third solenoid valve is fixedly connected and communicated on the protective gas path.

[0017] Optionally, the length of the protective gas pipeline is more than three times the length of the main gas pipeline.

[0018] This application includes at least one of the following beneficial technical effects:

[0019] 1. Through the setting of the control member (such as the first solenoid valve) in this application, this application can accurately control whether the gas path between the intake pipe and the sensor body is conducted. When measurement is not required, closing the control member can effectively isolate the sensor from the high-oxygen-content environment (such as air) outside, thereby preventing the sensor electrolyte from being quickly exhausted due to long-term exposure to high-concentration oxygen, and prolonging the service life of the sensor.

[0020] 2. Through the design of the protective gas pipeline in this application, the isolation effect between the sensor and the external environment is further enhanced, and the influence of external oxygen on the sensor is further reduced. The protective gas pipeline can also play a role in stabilizing gas flow and reducing gas fluctuations. When gas flows in the main gas pipeline, due to factors such as resistance and inertia, the gas flow may generate fluctuations. The existence of the protective gas pipeline can reduce such fluctuations and make the gas flow more stable, thereby improving the stability and reliability of detection.

[0021] 3. By providing a second solenoid valve at one end of the main gas pipeline close to the exhaust pipe, the present application can effectively prevent the backflow of gas in the main gas pipeline when measurement is not required. This design ensures that the sensor is not interfered by external gas in the closed state, further improving the stability and accuracy of measurement. At the same time, this also provides conditions for the sensor to quickly return to a stable state during the next measurement, reducing the waiting time before measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. 6 is an overall connection schematic diagram of a gas pipeline structure for detecting trace oxygen by an electrochemical method according to Embodiment 1 of the present application;

[0023] Figure 2 FIG. 10 is an overall connection schematic diagram of a gas pipeline structure for detecting trace oxygen by an electrochemical method according to Embodiment 2 of the present application.

[0024] DESCRIPTION OF THE REFERENCE NUMERALS: 1, intake pipe; 2, exhaust pipe; 3, main gas pipeline; 4, second solenoid valve; 5, sensor body; 6, protective gas pipeline; 61, third solenoid valve; 7, first solenoid valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following further elaborates on the present application Figure 1-2 with reference to the accompanying drawings.

[0026] Embodiment 1 of the present application discloses a gas pipeline structure for detecting trace oxygen by an electrochemical method.

[0027] Embodiment 1

[0028] Referring to Figure 1 , a gas pipeline structure for detecting trace oxygen by an electrochemical method includes an intake pipe 1, an exhaust pipe 2, a main gas pipeline 3, a second solenoid valve 4, a sensor body 5, a protective gas pipeline 6, and a control member.

[0029] Referring to Figure 1 , the intake pipe 1 and the exhaust pipe 2 are respectively fixedly communicated with both ends of the main gas pipeline 3, the sensor body 5 is installed on the main gas pipeline 3, and both ends of the protective gas pipeline 6 are respectively fixedly communicated with both ends of the main gas pipeline 3. The joints of the intake pipe 1, the main gas pipeline 3, and the protective gas pipeline 6, as well as the joints of the exhaust pipe 2, the main gas pipeline 3, and the protective gas pipeline 6, are fixedly communicated by three-way valves.

[0030] Referring to Figure 1, both the control member and the second solenoid valve 4 are installed on the main gas pipeline 3. The control member and the second solenoid valve 4 are located on both sides of the sensor body 5. The control member is located at one end of the main gas pipeline 3 close to the intake pipe 1. The control member adopts the first solenoid valve 7. In other embodiments, the control member can also adopt an intelligent electric valve, an adjustable two-way valve, or an electric regulating valve, etc. The second solenoid valve 4 is located at one end of the main gas pipeline 3 close to the exhaust pipe 2. The second solenoid valve 4 is fixedly communicated with the main gas pipeline 3. The second solenoid valve 4 is used to prevent the gas in the main gas pipeline 3 from flowing back.

[0031] Referring to Figure 1 , the protective gas pipeline 6 is spiral. The protective gas pipeline 6 is selected as a spiral gas path extension pipe made of stainless steel pipe with a diameter of 3. The number of turns is more than 20. The length of the protective gas pipeline 6 is more than three times the length of the main gas pipeline 3.

[0032] The implementation principle of the gas path structure for detecting trace oxygen by electrochemistry in the embodiment of the present application is as follows: During operation, the intake pipe 1 introduces the gas to be measured into the main gas pipeline 3. The gas contacts the electrochemistry sensor body 5 during the flow process. The main gas pipeline 3 serves as the main channel for gas flow to ensure that the gas can flow smoothly through the sensor body 5. When the gas diffuses into the sensor, an oxidation reaction occurs on the electrode surface, generating a current. This current is proportional to the concentration of oxygen. Therefore, the content of oxygen can be determined by measuring the magnitude of the current.

[0033] The control member (such as the first solenoid valve 7) is located at one end of the main gas pipeline 3 close to the intake pipe 1 and is used to control the entry of gas. By remotely controlling the opening of the first solenoid valve 7, the time and flow rate of gas entering the main gas pipeline 3 can be precisely controlled. The second solenoid valve 4 is located at one end of the main gas pipeline 3 close to the exhaust pipe 2 and is used to prevent gas from flowing back. When the detection is completed or the gas flow needs to be stopped, the second solenoid valve 4 closes to ensure that the gas in the main gas pipeline 3 does not flow backward.

[0034] When the external environment where the instrument is located is air, since the oxygen content in the air is relatively high, at this time, the first solenoid valve 7 is remotely controlled to close to protect the electrochemistry sensor body 5 from the interference and pollution of the external environment and quickly deplete the electrolyte of the oxygen sensor. Through the first solenoid valve 7, the opening and closing of the main gas pipeline 3 can be remotely and automatically controlled, thereby preventing the sensor electrolyte from being quickly depleted due to exposure to high-concentration oxygen.

[0035] The protective gas pipeline 6 is located around the main gas pipeline 3, forming a spiral extension pipeline. It is mainly used to protect the electrochemical sensor body 5 from external environmental interference and pollution. Through the spiral design, the gas resistance of the protective gas pipeline 6 can be increased. When the first solenoid valve 7 is opened, at this time, the intake pipe 1 is connected to the main gas pipeline 3 and the protective gas pipeline 6 at the same time. Then, the spirally arranged protective gas pipeline 6 has a large resistance. Therefore, during normal detection, it can cause all the gas to be measured to flow through the main gas pipeline 3, so as to complete the detection work normally.

[0036] In addition, the protective gas pipeline 6 can also play a role in stabilizing gas flow and reducing gas fluctuations. When the gas flows in the main gas pipeline 3, due to factors such as resistance and inertia, the gas flow may generate fluctuations. The existence of the protective gas pipeline 6 can reduce such fluctuations, make the gas flow more stable, and thus improve the stability and reliability of detection.

[0037] Embodiment 2

[0038] Refer to Figure 2 This embodiment is different from Embodiment 1 in that: the protective gas pipeline 6 is a straight pipe, and a third solenoid valve 61 is fixedly connected to one end of the protective gas pipeline 6 close to the intake pipe 1.

[0039] In this embodiment, by setting the third solenoid valve 61 to directly control the opening and closing of the protective gas pipeline 6, the flow direction of the gas to be measured can be accurately controlled, which is beneficial to ensuring the accuracy of detection.

[0040] The above are all the preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A gas path structure for detecting trace oxygen by electrochemical method, characterized in that: It comprises an air intake pipe (1), an exhaust pipe (2), a main air path pipe (3), a sensor body (5), a protective air path pipe (6) and a control component; The air inlet pipe (1) and the air outlet pipe (2) are respectively fixedly connected to two ends of the main air path pipe (3); The sensor body (5) is installed on the main gas line pipe (3); Both ends of the protective gas line pipe (6) are respectively fixedly connected to the main gas line pipe (3); The connection between the air intake pipe (1), the main air line pipe (3) and the protective air line pipe (6), and the connection between the exhaust pipe (2), the main air line pipe (3) and the protective air line pipe (6) are all fixedly connected by a three-way valve; The control component is installed on the main gas line pipe (3) and is located at one end of the main gas line pipe (3) close to the intake pipe (1). The control component is used to control whether the gas line between the intake pipe (1) and the sensor body (5) is connected.

2. The gas path structure for detecting trace oxygen by electrochemical method according to claim 1, characterized in that: The control component comprises a first solenoid valve (7), and the first solenoid valve (7) is fixedly connected to the main gas line pipe (3).

3. The gas path structure for detecting trace oxygen by electrochemical method according to claim 2, characterized in that: The gas circuit structure further comprises a second solenoid valve (4), the second solenoid valve (4) being located at one end of the main gas circuit pipe (3) close to the exhaust pipe (2), the second solenoid valve (4) being fixedly connected to the main gas circuit pipe (3), and the second solenoid valve (4) being used to prevent gas backflow in the main gas circuit pipe (3).

4. The gas path structure for detecting trace oxygen by electrochemical method according to claim 1, characterized in that: The protective gas circuit pipe (6) is arranged in a spiral shape.

5. The gas path structure for detecting trace oxygen by electrochemical method according to claim 1, characterized in that: The protective gas circuit is fixedly connected to a third solenoid valve (61).

6. The gas path structure for detecting trace oxygen by electrochemical method according to claim 4, characterized in that: The length of the protective gas line pipe (6) is more than three times the length of the main gas line pipe (3).

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