Detector for protecting electrochemical trace oxygen sensor

Abstract

The utility model discloses a detector for protecting an electrochemical trace oxygen sensor, which comprises a detector pool body, a first self-closing valve and a second self-closing valve, a detection chamber is arranged in the detector pool body, an air inlet hole and an air outlet hole which are communicated with the detection chamber are arranged on the detector pool body, the first self-closing valve is communicated with the air inlet hole, and the second self-closing valve is communicated with the air outlet hole; the opening pressure of the first self-closing valve and the opening pressure of the second self-closing valve are both greater than or equal to the minimum working pressure of the electrochemical trace oxygen sensor; according to the utility model, the first self-closing valve and the second self-closing valve which are connected with the air inlet and the air outlet of the detector pool body of the detection chamber are arranged, so that the electrochemical microsensor can be automatically protected through the self-closing valves when the detected gas in the detection gas circuit has no pressure, underpressure and overpressure.

Description

Technical Field

[0001] The utility model relates to a field, in particular to a detector for protecting 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 protecting an electrochemical trace oxygen sensor, so as to solve the problem that the electromagnetic valves arranged at the air inlet and the air outlet of the existing detector need to be connected to the 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 protecting 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 is characterized in that it also comprises a first self-closing valve connected to the air inlet and a second self-closing valve connected to the air outlet, and the opening pressure of the first self-closing valve and the opening pressure of the second self-closing 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 self-closing valve and the air inlet, reacts with the electrochemical trace oxygen sensor, and then is discharged through the air outlet and the second self-closing 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 with the top inlet 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 self-closing 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 head joint, an intermediate joint and a tail joint which are sealed and connected in sequence; a mounting groove is provided in the intermediate joint, and air holes which axially penetrate the mounting groove are provided in the middle of the head joint and the tail joint respectively; and multiple layers of metal sintered mesh are installed in the mounting groove.

[0012] Furthermore, the multi-layer metal sintered mesh is interference fit with the mounting groove.

[0013] Furthermore, the head joint is threadedly connected to the middle joint and a first sealing ring is provided between the head joint and the middle joint.

[0014] Furthermore, the middle joint is threadedly connected to the tail joint, and a second sealing ring is provided between the middle joint and the tail joint.

[0015] Furthermore, a flow meter is provided at the air outlet of the second self-closing valve.

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

[0018] The beneficial effects of the utility model are as follows: by arranging the first self-closing valve and the second self-closing valve connected to the air inlet and the air outlet of the detector cell body, when the measured gas in the detection gas path is under pressure, under pressure or over pressure, the self-closing valve can automatically close, thereby realizing automatic protection of the electrochemical trace sensor; in particular, when the electrochemical trace oxygen analyzer is not working (transportation, shutdown, maintenance, etc.), that is, there is no pressure in the gas path, the first self-closing valve and the second self-closing valve are automatically closed, and the electrochemical trace oxygen sensor is sealed in a closed detection chamber, effectively protecting the electrochemical trace oxygen sensor from contact with oxygen and extending the service life; the self-closing valve has a simple structure, does not require an external control circuit, is low in cost, and has stable performance, thereby simultaneously improving the stability of the entire detector. 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 diagram of the structure of a gas buffer according to an embodiment of the utility model.

[0022] Wherein: 1. gas buffer; 11. straight-through ferrule joint; 12. intermediate joint; 13. internal thread joint; 14. first sealing ring; 15. second sealing ring; 16. multi-layer metal sintered mesh; 2. first self-closing valve; 3. first metal ferrule joint; 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. third sealing ring; 7. second metal ferrule joint; 8. second self-closing valve; 9. flow meter. DETAILED DESCRIPTION

[0023] like Figure 1The detector for protecting the electrochemical trace oxygen sensor 5 shown in the figure includes a detector cell body 4, a first self-closing valve 2 and a second self-closing 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 self-closing valve 2 is connected to the air inlet 41, and the second self-closing valve 8 is connected to the air outlet 43. The opening pressure of the first self-closing valve 2 and the opening pressure of the second self-closing 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 self-closing 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 self-closing valve 8.

[0024] The present application sets a first self-closing valve 2 and a second self-closing valve 8 connected to the air inlet 41 and the air outlet 43 of the detector cell body 4. When the measured gas in the detection gas circuit is under pressure, under pressure or over pressure, the self-closing valve can automatically close, thereby automatically protecting the electrochemical trace sensor; in particular, when the electrochemical trace oxygen analyzer is not working (transportation, shutdown, maintenance, etc.), that is, when there is no pressure in the gas circuit, the first self-closing valve 2 and the second self-closing valve 8 are automatically closed, and the electrochemical trace oxygen sensor 5 is sealed in a closed detection chamber 42, effectively protecting the electrochemical trace oxygen sensor 5 from contact with oxygen and extending its service life; the self-closing valve has a simple structure, does not require an external control circuit, is low in cost, and has stable performance, thereby simultaneously 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 inlet 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 self-closing 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 an embodiment of the present application, the gas buffer 1 comprises a head joint 11, an intermediate joint 12 and a tail joint 13 which are sealed and connected in sequence; a mounting groove is provided in the intermediate joint 12, and a gas hole which axially penetrates the mounting groove is provided in the middle of the head joint 11 and the tail joint 13; a multi-layer metal sintered mesh 16 is installed in the mounting groove. The multi-layer metal sintered mesh 16 is a mesh-shaped dense layer formed by sintering metal, and has dense gas permeable holes inside, which can play a gas blocking role, buffer the instantaneous pressure, and ensure the normal measurement of the electrochemical trace oxygen sensor 5. Moreover, the mesh holes of each layer of metal sintered mesh are interlaced to form a uniform and ideal filtering structure; this structure not only overcomes the shortcomings of low strength, poor rigidity and unstable mesh shape of ordinary metal wire mesh, but also can reasonably match and design the pore size, permeability and strength characteristics of the material, so that it has excellent filtering accuracy, filtering impedance, mechanical strength, wear resistance, heat resistance and processability; the standard structure of metal sintered mesh is usually five layers, including protective layer, filtration control layer, dispersion layer, support skeleton layer and skeleton layer; this structure makes the filter layer well protected and diverted, ensuring the uniformity and high stability of filtering accuracy. In addition, metal sintered mesh also has good heat resistance and cleanability, and can be used in various harsh working environments.

[0028] According to an embodiment of the present application, the multi-layer metal sintered mesh 16 is interference-fitted with the mounting groove; the multi-layer metal sintered mesh 16 has a simple assembly process and good stability.

[0029] According to one embodiment of the present application, the head joint 11 is threadedly connected to the intermediate joint 12 and a first sealing ring 14 is provided between the head joint 11 and the intermediate joint 12; the head joint 11 is a straight-through compression joint, and the end at which the straight-through compression joint is connected to the intermediate joint 12 is provided with a first external thread, and the end at which the intermediate joint 12 is connected to the straight-through compression joint is provided with a first internal thread matching the first external thread; the gas buffer 1 is connected to the air intake metal pipe through the straight-through compression joint.

[0030] According to one embodiment of the present application, the intermediate joint 12 is threadedly connected to the tail joint 13 and a second sealing ring 15 is provided between the intermediate joint 12 and the tail joint 13; one end where the intermediate joint 12 is connected to the tail joint 13 is provided with a second external thread, and one end where the tail joint 13 is connected to the intermediate joint 12 is provided with a second internal thread that matches the second external thread.

[0031] According to one embodiment of the present application, a flow meter 9 is provided at the outlet end of the second self-closing valve 8; by introducing the flow meter 9 at the outlet end, it is not only convenient to monitor the flow rate in the gas circuit so as to adjust the flow rate in time, but also can be used to prompt the user whether the electrochemical trace oxygen sensor 5 is in working condition.

[0032] According to an embodiment of the present application, a first metal ferrule joint 3 is welded to the air inlet 41 of the detector cell body 4 , and the first self-closing 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 self-closing 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 protecting 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 self-closing valve connected to the air inlet and a second self-closing valve connected to the air outlet, wherein the opening pressure of the first self-closing valve and the opening pressure of the second self-closing valve are both greater than or equal to the minimum working pressure of the electrochemical trace oxygen sensor.

2. The detector for protecting 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 inlet of the guide groove, and the air outlet is arranged at the bottom of the detection chamber.

3. The detector for protecting an electrochemical trace oxygen sensor according to claim 1, characterized in that: The air inlet end of the first self-closing valve is connected to a gas buffer for providing a buffer pressure for the gas to be measured.

4. The detector for protecting an electrochemical trace oxygen sensor according to claim 3, characterized in that: The gas buffer comprises a head joint, an intermediate joint and a tail joint which are sealed and connected in sequence; a mounting groove is arranged in the intermediate joint, and air holes which axially penetrate the mounting groove are arranged in the middle of the head joint and the tail joint respectively; and multiple layers of metal sintered mesh are installed in the mounting groove.

5. The detector for protecting an electrochemical trace oxygen sensor according to claim 4, characterized in that: The multi-layer metal sintered mesh is interference-fitted with the mounting groove.

6. The detector for protecting an electrochemical trace oxygen sensor according to claim 4, characterized in that: The head joint is threadedly connected to the middle joint, and a first sealing ring is arranged between the head joint and the middle joint.

7. The detector for protecting an electrochemical trace oxygen sensor according to claim 4, characterized in that: The middle joint is threadedly connected to the tail joint, and a second sealing ring is arranged between the middle joint and the tail joint.

8. The detector for protecting an electrochemical trace oxygen sensor according to claim 1, characterized in that: A flow meter is provided at the gas outlet end of the second self-closing valve.

9. The detector for protecting 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 self-closing valve is connected to the first metal ferrule joint through a metal pipe.

10. The detector for protecting 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 self-closing valve is connected to the second metal ferrule joint through a metal pipe.

Images