Detector for prolonging service life of electrochemical trace oxygen sensor

Abstract

The utility model discloses a detector for prolonging the service life of an electrochemical trace oxygen sensor, which comprises a detector tank body, and an air inlet and an air outlet which are communicated with a detection chamber are arranged on the detector tank body; the electrochemical trace oxygen sensor further comprises a first one-way valve communicated with the air inlet hole and a second one-way valve communicated with the air outlet hole, and the opening pressure of the first one-way valve and the opening pressure of the second one-way valve are both larger than or equal to the minimum working pressure of the electrochemical trace oxygen sensor. The first one-way valve and the second one-way valve are defaulted to be in a closed state and are automatically opened when the pressure of the air inlet of the detector is greater than or equal to the opening pressure of the first one-way valve and the second one-way valve; when the air inlet of the detector pool body has no air inlet pressure or is under pressure, the first one-way valve and the second one-way valve are automatically closed, and the electrochemical trace oxygen sensor is sealed in a closed detection chamber, so that the electrochemical trace oxygen sensor can be effectively protected from being in contact with oxygen, and the service life of the electrochemical trace oxygen sensor is prolonged.

Description

Technical Field

[0001] The utility model relates to a field, in particular to a detector for extending the life of an electrochemical trace oxygen sensor. Background Art

[0002] Electrochemical trace oxygen sensor, commonly known as "fuel cell", is a consumable sensor. Its life depends on the oxygen consumption. The sensor should be avoided as much as possible under high concentration (greater than 1000ppm).

[0003] The current generated by the oxygen participating in the reaction in the electrochemical trace oxygen sensor is proportional to the oxygen content in the sample gas. The output signal of the sensor is related to the oxygen content in the sample gas. Through the connection of the external circuit, the charge transfer in the reaction, that is, the size of the current, is proportional to the oxygen participating in the reaction, so that the oxygen content in the sample gas can be measured. This oxygen content is usually several ppm or lower.

[0004] The lower the oxygen concentration in the process gas, the less oxygen the oxygen sensor consumes, and the longer the life of the oxygen sensor. The storage time of the instrument oxygen sensor (storage under oxygen content below 10ppm) can reach 2 years. Once high-concentration oxygen contacts the electrochemical trace oxygen sensor, the product of the chemical reaction, PbO, will quickly reach the limit specified by the solution, which will greatly shorten the life of the sensor. If this sensor is exposed to air for a long time, its life may be only about a week.

[0005] The invention patent with patent number CN201310542568.1 discloses an electrochemical trace oxygen analyzer that effectively extends the service life of the sensor, including a gas circuit system, a sensor system, a control system, a power supply system and a display system, wherein the gas circuit system is connected to the sensor system, and the control system is respectively connected to the gas circuit system, the sensor system, the power supply system and the display system, wherein the sensor system includes a sensor and a test chamber with a sensor accommodation space, wherein the air inlet and the air outlet provided in the test chamber are connected to the sensor, and the air inlet and the air outlet are also provided with a solenoid valve, and the solenoid valve is connected to the control system. When the electrochemical trace oxygen analyzer of the patent is not working, a solenoid valve is usually installed at the air inlet and the air outlet of the electrochemical trace oxygen sensor to isolate the electrochemical trace oxygen sensor from oxygen, but the solenoid valve needs to be connected to the control circuit, and this solution is more complicated and has lower performance stability.

[0006] In addition, the maximum working pressure of the electrochemical trace oxygen sensor is generally not more than 120KPa (gauge pressure), otherwise the measurement will be confused, and when the pressure is further increased, the electrochemical trace oxygen sensor itself will be damaged to varying degrees. However, the prior art does not have corresponding protection measures to protect the electrochemical trace oxygen sensor; and in the prior art, the detector cell body usually has a dead volume, and it takes a long time to replace the dead volume, which has a great impact on the response time of the electrochemical trace oxygen sensor. Utility Model Content

[0007] The utility model aims to provide a detector for extending the life of an electrochemical trace oxygen sensor, so as to solve the problem that the solenoid valves arranged at the air inlet and air outlet of the existing detector need to be connected to a control circuit, resulting in a complex structure and low performance stability.

[0008] In order to solve the above technical problems, the present invention provides a detector for extending the service life of an electrochemical trace oxygen sensor, comprising a detector cell body, a detection chamber is arranged in the detector cell body, the electrochemical trace oxygen sensor is installed in the detection chamber, and an air inlet and an air outlet connected to the detection chamber are arranged on the detector cell body. The detector cell body is characterized in that it also comprises a first one-way valve connected to the air inlet and a second one-way valve connected to the air outlet, and the opening pressure of the first one-way valve and the opening pressure of the second one-way valve are both greater than or equal to the minimum working pressure of the electrochemical trace oxygen sensor; the measured gas enters the detection chamber through the first one-way valve and the air inlet, reacts with the electrochemical trace oxygen sensor, and then is discharged through the air outlet and the second one-way valve.

[0009] Furthermore, a detection chamber is provided in the detector cell body, the electrochemical trace oxygen sensor is installed in the detection chamber, and the measuring electrode of the electrochemical trace oxygen sensor is arranged at the bottom of the detection chamber; a guide groove is provided in the middle and upper part of the inner wall of the detection chamber, and the guide groove is arranged in a spiral shape along the inner wall of the guide chamber; the air inlet is provided on the side wall of the detection chamber and is connected to the top entrance position of the guide groove, and the air outlet is provided at the bottom of the detection chamber.

[0010] Furthermore, the air inlet end of the first one-way valve is connected to a gas buffer for providing a buffer pressure for the gas to be measured.

[0011] Furthermore, the gas buffer includes a first straight-through joint, a second straight-through joint and a capillary tube; the first straight-through joint is connected to the second straight-through joint, and an annular groove is provided on the inner side of one end where the first straight-through joint is connected to the second straight-through joint; a rubber gasket is installed in the annular groove, and a mounting hole is provided in the middle of the rubber gasket axially passing through it, and the capillary tube is fixed in the mounting hole.

[0012] Further, the first straight joint is threadedly connected to the second straight joint, and a first sealing ring is provided between the first straight joint and the second straight joint.

[0013] Further, the annular groove is formed by sinking the inner side of one end where the first straight joint is connected to the second straight joint toward one end of the first straight joint away from the second straight joint, an internal thread is provided at one end where the first straight joint is connected to the second straight joint, an external thread is provided at one end where the second straight joint is connected to the first straight joint, and a rubber gasket is fixed between the annular groove and the end of the second straight joint extending into the first straight joint.

[0014] Furthermore, a pneumatic overflow valve is provided at the gas outlet of the second one-way valve, and the opening pressure of the pneumatic overflow valve is the maximum working pressure of the electrochemical trace oxygen.

[0015] Furthermore, the overflow port of the pneumatic overflow valve is connected to an airflow alarm.

[0016] Furthermore, a first metal ferrule joint is welded at the air inlet of the detector cell body, and the first one-way valve is connected to the first metal ferrule joint through a metal pipe.

[0017] Furthermore, a second metal ferrule joint is welded at the air outlet of the detector cell body, and the first one-way valve and the second metal ferrule joint are connected through a metal pipe.

[0018] The beneficial effects of the utility model are as follows: the first one-way valve and the second one-way valve are in a closed state by default, and when the pressure at the detector air inlet is greater than or equal to the opening pressure of the first one-way valve and the second one-way valve, the first one-way valve and the second one-way valve are automatically opened; when there is no air inlet pressure or underpressure at the air inlet of the detector cell body, the first one-way valve and the second one-way valve are automatically closed, and the electrochemical trace oxygen sensor is sealed in a closed detection chamber, which can effectively protect the electrochemical trace oxygen sensor from contact with oxygen and extend its service life; the one-way valve has a simple structure, does not require an external control circuit, has low cost, and has stable performance, thereby improving the stability of the entire detector at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The same reference numerals are used in these drawings to represent the same or similar parts. The exemplary embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0020] Figure 1 It is a structural schematic diagram of an embodiment of the utility model.

[0021] Figure 2 The figure is a schematic structural diagram of a gas buffer according to an embodiment of the utility model.

[0022] Among them: 1. gas buffer; 11. first straight-through connector; 12. second straight-through connector; 13. rubber gasket; 14. capillary; 15. first sealing ring; 2. first one-way valve; 3. first metal ferrule connector; 4. detector cell body; 41. air inlet; 42. detection chamber; 421. guide groove; 43. air outlet; 5. electrochemical trace oxygen sensor; 6. cover body; 61. second sealing ring; 7. second metal ferrule connector; 8. second one-way valve; 9. pneumatic overflow valve; 91. overflow port; 92. alarm. DETAILED DESCRIPTION

[0023] like Figure 1 The detector for protecting the electrochemical trace oxygen sensor 5 shown in the figure includes a detector cell body 4, a first one-way valve 2 and a second one-way valve 8. A detection chamber 42 is provided in the detector cell body 4. The electrochemical trace oxygen sensor 5 is installed in the detection chamber 42 through a cover body and a sealing ring. An air inlet 41 and an air outlet 43 connected to the detection chamber are provided on the detector cell body 4. The first one-way valve 2 is connected to the air inlet 41, and the second one-way valve 8 is connected to the air outlet 43. The opening pressure of the first one-way valve 2 and the opening pressure of the second one-way valve 8 are both greater than or equal to the minimum working pressure of the electrochemical trace oxygen sensor 5. The measured gas enters the detection chamber 42 through the first one-way valve 2 and the air inlet 41, reacts with the electrochemical trace oxygen sensor 5, and then is discharged through the air outlet 43 and the second one-way valve 8.

[0024] The first one-way valve 2 and the second one-way valve 8 are in a closed state by default. When the pressure at the detector inlet is greater than or equal to the opening pressure of the first one-way valve 2 and the second one-way valve 8, the first one-way valve 2 and the second one-way valve 8 are automatically opened; when there is no inlet pressure or underpressure at the detector cell inlet, the first one-way valve 2 and the second one-way valve 8 are automatically closed, and the electrochemical trace oxygen sensor 5 is sealed in a closed detection chamber 42, which can effectively protect the electrochemical trace oxygen sensor 5 from contact with oxygen and extend its service life; the one-way valve has a simple structure, does not require an external control circuit, has low cost, and stable performance, thereby also improving the stability of the entire detector.

[0025] According to one embodiment of the present application, a detection chamber 42 is provided in the detector cell body 4, and an electrochemical trace oxygen sensor 5 is installed in the detection chamber 42. The measuring electrode of the electrochemical trace oxygen sensor 5 is arranged at the bottom of the detection chamber 42; a guide groove 421 is provided in the middle and upper part of the inner wall of the detection chamber 42, and the guide groove 421 is arranged in a spiral shape along the inner wall of the guide chamber; an air inlet 41 is provided on the side wall of the detection chamber 42 and is connected to the top entrance position of the guide groove 421, and an air outlet 43 is provided at the bottom of the detection chamber 42. The cross section of the guide groove 421 can be set to a rectangular, arc, triangular or trapezoidal groove-shaped structure. The measured gas enters the guide groove 421 from the air inlet 41 at the top of the detector cell body 4, and the measured gas passes through the guide groove 421 from top to bottom to the bottom of the guide chamber, which can facilitate gas flow to quickly replace the dead volume, thereby reducing the measurement response time of the electrochemical trace oxygen sensor 5 and improving the measurement accuracy.

[0026] According to one embodiment of the present application, a gas buffer 1 for providing a buffer pressure for the gas to be measured is connected to the gas inlet end of the first one-way valve 2. When the detector is working, if the gas to be measured in the gas path has an instantaneous excessive pressure, the gas buffer 1 can buffer the instantaneous excessive pressure.

[0027] According to one embodiment of the present application, the gas buffer includes a first straight joint 11, a second straight joint 12 and a capillary tube 14; the first straight joint 11 is connected to the second straight joint 12, and an annular groove is provided on the inner side of one end where the first straight joint 11 and the second straight joint 12 are connected; a rubber gasket 13 is installed in the annular groove, and a mounting hole axially passing through the middle of the rubber gasket 13 is provided, and the capillary tube 14 is fixed in the mounting hole. The capillary tube 14 is installed in the air flow channel connected to the first straight joint 11 and the second straight joint 12 through the rubber gasket 13 ring, wherein the thickness of the rubber gasket 13 is greater than the depth of the annular groove, and the capillary tube 14 can be sealed. The length of the capillary tube 14 can be set according to the actual working scene to change the gas resistance of the pipeline, thereby changing the buffering time of the gas.

[0028] According to an embodiment of the present application, the first straight joint 11 is threadedly connected to the second straight joint 12 , and a first sealing ring 15 is disposed between the first straight joint 11 and the second straight joint 12 .

[0029] According to one embodiment of the present application, the annular groove is formed by sinking the inner side of one end where the first straight joint 11 and the second straight joint 12 are connected toward the end of the first straight joint 11 away from the second straight joint 12, the end where the first straight joint 11 and the second straight joint 12 are connected is provided with an internal thread, the end where the second straight joint 12 and the first straight joint 11 are connected is provided with an external thread, and the rubber gasket 13 is fixed between the annular groove and the end of the second straight joint 12 extending into the first straight joint 11. During assembly, the capillary 14 is first fixed in the mounting hole of the rubber gasket 13, and then one end of the capillary 14 is extended into the first straight joint 11 until the rubber gasket 13 is embedded in the annular groove; then the other end of the capillary 14 is extended into the first straight joint 11, and the second straight joint 12 is screwed into the first straight joint 11 to press the rubber gasket 13 into the annular groove, so as to achieve a sealed installation of the capillary 14.

[0030] According to one embodiment of the present application, a pneumatic relief valve 9 is provided at the outlet of the second one-way valve, and the opening pressure of the pneumatic relief valve 9 is the maximum working pressure of the electrochemical trace oxygen. If the pressure in the pipeline exceeds the set pressure of the pneumatic relief valve 9, the pneumatic relief valve 9 discharges the pressure in the gas circuit through a bypass channel connected to the overflow port 91, thereby preventing the electrochemical trace sensor from being damaged by excessive pressure shock.

[0031] According to an embodiment of the present application, the overflow port 91 of the pneumatic overflow valve 9 is connected to an airflow alarm 92 , and when gas flows out from the bypass channel through the overflow port 91 , the airflow alarm 92 sends out an alarm signal.

[0032] According to an embodiment of the present application, a first metal ferrule joint 3 is welded at the air inlet 41 of the detector cell body 4 , and the first one-way valve 2 is connected to the first metal ferrule joint 3 via a metal pipe.

[0033] According to an embodiment of the present application, a second metal ferrule joint 7 is welded to the air outlet 43 of the detector cell body 4 , and the first one-way valve 2 is connected to the second metal ferrule joint 7 via a metal pipe.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A detector for extending the life of an electrochemical trace oxygen sensor, comprising a detector cell body, a detection chamber is provided in the detector cell body, the electrochemical trace oxygen sensor is installed in the detection chamber, and an air inlet and an air outlet connected to the detection chamber are provided on the detector cell body, characterized in that: It also includes a first one-way valve connected to the air inlet and a second one-way valve connected to the air outlet, wherein the opening pressure of the first one-way valve and the opening pressure of the second one-way valve are both greater than or equal to the minimum working pressure of the electrochemical trace oxygen sensor.

2. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 1, characterized in that: The measuring electrode of the electrochemical trace oxygen sensor is arranged at the bottom of the detection chamber; a guide groove is provided in the middle and upper part of the inner wall of the detection chamber, and the guide groove is arranged in a spiral shape along the inner wall of the guide chamber; the air inlet is arranged at the upper part of the side wall of the detection chamber and is connected with the top entrance position of the guide groove, and the air outlet is arranged at the bottom of the detection chamber.

3. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 2, characterized in that: The air inlet end of the first one-way valve is connected to a gas buffer for providing a buffer pressure for the gas to be measured.

4. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 3, characterized in that: The gas buffer includes a first straight joint, a second straight joint and a capillary tube; the first straight joint is connected to the second straight joint, and an annular groove is provided on the inner side of one end where the first straight joint is connected to the second straight joint; a rubber gasket is installed in the annular groove, and a mounting hole axially passing through the middle of the rubber gasket is provided, and the capillary tube is fixed in the mounting hole.

5. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 4, characterized in that: The first straight joint is threadedly connected to the second straight joint, and a first sealing ring is arranged between the first straight joint and the second straight joint.

6. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 5, characterized in that: The annular groove is formed by sinking the inner side of one end of the first straight joint connected to the second straight joint toward the end of the first straight joint away from the second straight joint. The end of the first straight joint connected to the second straight joint is provided with an internal thread, and the end of the second straight joint connected to the first straight joint is provided with an external thread. The rubber gasket is fixed between the annular groove and the end of the second straight joint extending into the first straight joint.

7. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 1, characterized in that: A pneumatic overflow valve is provided at the gas outlet end of the second one-way valve, and the opening pressure of the pneumatic overflow valve is the maximum working pressure of electrochemical trace oxygen.

8. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 7, characterized in that: The overflow port of the pneumatic overflow valve is connected with an airflow alarm.

9. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 1, characterized in that: A first metal ferrule joint is welded at the air inlet of the detector cell body, and the first one-way valve is connected to the first metal ferrule joint through a metal pipe.

10. The detector for extending the life of an electrochemical trace oxygen sensor according to claim 1, characterized in that: A second metal ferrule joint is welded at the air outlet of the detector cell body, and the first one-way valve is connected to the second metal ferrule joint through a metal pipe.

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