Gas concentration detection mechanism of combustible gas alarm

Abstract

The invention discloses a combustible gas alarm gas concentration detection mechanism which comprises a detector body, a detection assembly with a resistor is arranged in the detector body, the resistor is installed in the detection assembly, one end of the resistor is provided with an auxiliary mechanism with a platinum wire, and the platinum wire is connected with the resistor in series. A gas inlet mechanism with a gas inlet pipe is arranged on one side of the detection assembly, the gas inlet pipe is installed at the position, close to the platinum wire, of the detection assembly, a movable plate is installed in the gas inlet pipe, and a driving motor is installed on the outer surface of the movable plate. The flow path and the mixing effect of the gas are increased, the combustible gas is more uniformly distributed and mixed in the detector, the detection accuracy and reliability are improved, the flow rate of the combustible gas can be reduced through the design of the taper hole, impact and abrasion to a sensor in the detector are reduced, and the service life of the sensor is prolonged.

Description

Technical Field

[0001] The invention relates to the field of gas detection, in particular to a gas concentration detection mechanism for a combustible gas alarm. Background Art

[0002] The most common combustible gas alarms on the market are mainly based on catalytic combustion. Catalytic combustion sensors diffuse gas into the catalytic combustion chamber of the sensor and use catalysts to burn the combustible gas to generate heat, thereby changing the resistance of the sensing resistor, breaking the balance of the bridge, and generating a small voltage difference signal. This signal is proportional to the combustible gas concentration, thereby achieving the purpose of detecting the combustible gas concentration.

[0003] When the existing combustible gas concentration is detected, the distribution of combustible gas in the air is often uneven due to the complex changes in the amount of combustible gas leakage and environmental conditions. When these unevenly distributed combustible gases enter the detector, if there is insufficient oxygen supply, they cannot effectively contact the catalyst on the sensor, resulting in an unstable combustion reaction. At the same time, if the combustion reaction of the combustible gas on the catalyst is unstable, the heat generated and the change in the induction resistance will also become unstable, resulting in the breakdown of the bridge balance and the fluctuation of the small voltage difference signal. This fluctuation will interfere with the normal operation of the detector, making it difficult to accurately measure the concentration of the combustible gas. Summary of the invention

[0004] The purpose of the present invention is to provide a gas concentration detection mechanism for a combustible gas alarm to solve the problem in the above background technology that when unevenly distributed combustible gases enter the detector, they cannot effectively and fully contact with the catalyst on the sensor, thereby causing the combustion reaction to be unstable, making it difficult to accurately measure the concentration of the combustible gas.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a gas concentration detection mechanism of a combustible gas alarm, comprising a detector body, a detection component with a resistor is arranged inside the detector body, the resistor is installed inside the detection component, an auxiliary mechanism with a platinum wire is arranged at one end of the resistor, the platinum wire is connected in series with the resistor, an intake mechanism with an intake pipe is arranged on one side of the detection component, the intake pipe is installed at the detection component close to the platinum wire, a movable plate is installed inside the intake pipe, a drive motor is installed on the outer surface of the movable plate, a spiral impeller is fixedly installed on the output shaft of the drive motor, a plurality of air flow holes are opened on the outer surface of the spiral impeller, a tapered hole is opened inside the movable plate, the large diameter end of the tapered hole is close to the platinum wire, and the small diameter end of the tapered hole is close to the spiral impeller.

[0006] As a preferred technical solution of the present invention, the outer surface of the air inlet pipe is connected to a drying box containing solid calcium chloride particles, and a first protective net is installed on the surface of the drying box close to the inner wall of the air inlet pipe.

[0007] As a preferred technical solution of the present invention, a power supply body is installed inside the detector body, a controller is installed on the outer surface of the detector body, the resistor is electrically connected to the power supply body and the controller respectively through wires, the auxiliary mechanism includes a conductive column, a first conductive plate and a second conductive plate are electrically connected in the middle of the wire, and a spring is installed between the first conductive plate and the second conductive plate, the conductive column is slidably connected inside the first conductive plate and the second conductive plate, and limit baffles are provided on surfaces of the first conductive plate and the second conductive plate that are close to each other, the platinum wire is inserted inside the conductive column, and three platinum wires are provided.

[0008] As a preferred technical solution of the present invention, a support frame is installed inside the detector body, a rubber sleeve is arranged between the support frame and the detector body, a support plate is installed between the support frame and the conductive column, and the cross-section of the support plate is arc-shaped, and the platinum wire slides in the top groove of the support plate; the free end of the platinum wire is connected and installed with a base, and a sealing plug is installed on the surface of the platinum wire located inside the support frame.

[0009] As a preferred technical solution of the present invention, a pressure relief pipe is arranged inside the detector body near the platinum wire, a pressure relief valve is arranged on the pressure relief pipe, a pressure gauge is installed on the outer surface of the detector body, and the pressure relief valve is electrically connected to the pressure gauge through the power supply body.

[0010] As a preferred technical solution of the present invention, an oxygen supply mechanism is arranged inside the detection component, and the oxygen supply mechanism includes an oxygen tank. The oxygen tank is opened inside the detector body, and the top of the oxygen tank is connected to an oxygen supply pipeline. A connecting pipe is connected to the surface of the oxygen tank close to the platinum wire, and an electronic valve is installed on the connecting pipe. A combustible gas alarm probe is installed inside the detector body close to the platinum wire, and the combustible gas alarm probe is electrically connected to the electronic valve and the alarm through a controller.

[0011] As a preferred technical solution of the present invention, a protective mechanism is arranged inside the detector body, and the protective mechanism includes activated carbon crushed. A groove is opened inside the detector body, and a second protective net is installed inside the groove. The activated carbon crushed is piled on one side of the second protective net, and the groove on the other side of the second protective net is connected to the space where the platinum wire is located and is provided with an exhaust hole, and a top plate is installed at the top of the detector body near the activated carbon crushed, a cavity is opened inside the detector body near the groove, and the bottom end of the cavity is connected to the space where the platinum wire is located, a piston is slidably installed inside the cavity, an airbag is installed on the surface of the piston close to the platinum wire, a movable plug is arranged inside the exhaust hole, a fixed plate is installed at the top of the movable plug, and a fixed rod is installed between the fixed plate and the piston.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The present invention increases the flow path and mixing effect of the gas through the design of the spiral impeller, so that the combustible gas is more evenly distributed and mixed inside the detector. This design helps the platinum wire to contact and react with the combustible gas more stably, thereby detecting the actual concentration of the combustible gas and improving the accuracy and reliability of the detection. The design of the tapered hole can slow down the flow rate of the combustible gas, reduce the impact and wear on the sensor inside the detector, and extend the service life of the sensor. At the same time, the tapered hole can also guide and disperse the gas, so that the gas is more evenly distributed inside the detector, further improving the accuracy of the detection.

[0014] 2. The present invention uses platinum wire as a catalyst. The heat generated by the platinum wire during the catalytic combustion process causes the resistance value to change. Combined with the precise resistance measurement technology, this change is proportional to the concentration of the combustible gas, thereby achieving high-precision measurement. In addition, the setting of the oxygen supply mechanism ensures the oxygen supply required for the full combustion of the combustible gas and the platinum wire, avoiding the problem of incomplete combustion caused by insufficient oxygen, further improving the accuracy and stability of the detection, and reducing the detection error caused by the fluctuation of the oxygen concentration.

[0015] 3. The present invention sets a pressure relief pipe and a pressure relief valve, as well as a pressure gauge, inside the detector body to monitor and adjust the internal pressure. When the concentration of combustible gas is extremely high or a large amount of heat flow is generated by the combustion of platinum wire, the pressure relief pipe can allow part of the gas to escape, thereby reducing the risk of explosion and enhancing the safety of the equipment. In addition, through the adsorption of activated carbon fragments, the invention can effectively adsorb harmful substances and gases generated during the combustion of platinum wire, avoiding secondary pollution to the environment and reducing potential harm to the environment and human body.

[0016] 4. In the present invention, when the platinum wire is damaged due to long-term use or harsh environment, the user only needs to simply disassemble the conductive column to replace the new platinum wire, without large-scale disassembly or repair of the entire sensor circuit. This not only reduces maintenance costs and time, but also improves the reliability and service life of the equipment. At the same time, platinum wires of different materials, specifications or performances can be selected for replacement according to actual needs to meet the detection of different gas concentrations and improve the detection range. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the detector main body of the present invention;

[0018] Figure 2 It is a side view structural schematic diagram of the present invention;

[0019] Figure 3 It is a schematic diagram of the internal structure of the detector body of the present invention;

[0020] Figure 4 It is a schematic diagram of the internal structure of the air intake pipe of the present invention;

[0021] Figure 5 It is a schematic diagram of the spiral impeller structure of the present invention;

[0022] Figure 6 is a schematic diagram of the platinum wire structure of the present invention;

[0023] Figure 7 It is a schematic diagram of the internal structure of the support frame of the present invention;

[0024] Figure 8 It is a schematic diagram of the cross-sectional structure of the support plate of the present invention;

[0025] Fig. 9 For the present invention Figure 4 Schematic diagram of the structure at A in FIG.

[0026] Fig.10 For the present invention Figure 4 Schematic diagram of the structure at point B in the figure.

[0027] In the figure: 1. detector body; 2. air intake mechanism; 21. air intake pipe; 22. spiral impeller; 23. drive motor; 24. movable plate; 25. cone hole; 26. drying box; 27. first protective net; 3. detection component; 31. power supply body; 32. wire; 33. auxiliary mechanism; 331. first conductive plate; 332. spring; 333. limit baffle; 334. second conductive plate; 335. platinum wire; 336. support plate; 337. sealing plug; 338. base; 339. guide Electric pole; 34. Resistor; 35. Controller; 36. Rubber sleeve; 37. Support frame; 4. Oxygen supply mechanism; 41. Combustible gas alarm probe; 42. Connecting pipe; 43. Oxygen chamber; 44. Oxygen supply pipeline; 5. Protection mechanism; 51. Top plate; 52. Activated carbon crushed; 53. Second protection net; 54. Exhaust hole; 55. Moving plug; 56. Fixed plate; 57. Air bag; 58. Piston; 59. Cavity; 510. Fixed rod; 511. Pressure gauge; 512. Pressure relief pipeline; 6. Alarm. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-10 , the present invention provides a technical solution for a gas concentration detection mechanism of a combustible gas alarm:

[0030] In some embodiments, the gas concentration detection mechanism of a combustible gas alarm includes a detector body 1, a detection component 3 with a resistor 34 is disposed inside the detector body 1, the resistor 34 is installed inside the detection component 3, and an auxiliary mechanism 33 with a platinum wire 335 is disposed at one end of the resistor 34, and the platinum wire 335 is connected in series with the resistor 34.

[0031] Among them, when the combustible gas enters the catalytic combustion chamber of the sensor, the platinum wire 335 acts as a catalyst to promote the flameless combustion of the combustible gas on its surface. The heat generated by this combustion reaction will increase the temperature of the platinum wire 335, thereby changing the resistance 34 value of the platinum wire 335. Since the resistance 34 rate of the platinum wire 335 changes with the change of temperature, the concentration of the combustible gas can be indirectly measured by monitoring the change of the resistance 34 value of the platinum wire 335.

[0032] In some embodiments, an air intake mechanism 2 with an air intake pipe 21 is provided on one side of the detection component 3. The air intake pipe 21 is installed on the detection component 3 near the platinum wire 335. A movable plate 24 is installed inside the air intake pipe 21. A driving motor 23 is installed on the outer surface of the movable plate 24. A spiral impeller 22 is fixedly installed on the output shaft of the driving motor 23. A plurality of air flow holes are opened on the outer surface of the spiral impeller 22.

[0033] Among them, the combustible gas in the air is introduced into the interior of the detector through the spiral impeller 22. The design of the spiral impeller can increase the flow path and mixing effect of the gas, so that the combustible gas can be more evenly distributed and mixed inside the detector; the air flow holes on the surface of the blades of the spiral impeller 22 can further promote the uniform mixing of the gas. This design enables the platinum wire 335 to contact and react with the combustible gas more stably, thereby detecting the actual concentration of the combustible gas, improving the accuracy and reliability of the detection.

[0034] In some embodiments, a tapered hole 25 is opened inside the movable plate 24 , the large diameter end of the tapered hole 25 is close to the platinum wire 335 , and the small diameter end of the tapered hole 25 is close to the spiral impeller 22 .

[0035] Among them, the flow rate of the combustible gas can be slowed down through the tapered hole 25, which can reduce the impact and wear on the sensor inside the detector, thereby extending the service life of the sensor; and when the combustible gas enters the detector through the tapered hole, it will be guided and dispersed to a certain extent, so that the gas can be more evenly distributed inside the detector, which helps to improve the accuracy of detection. In addition, slowing down the flow rate of the combustible gas can also reduce false alarms and missed alarms caused by excessive gas flow.

[0036] In some embodiments, a drying box 26 containing solid calcium chloride particles is installed on the outer surface of the air inlet pipe 21 , and a first protective net 27 is installed on the surface of the drying box 26 close to the inner wall of the air inlet pipe 21 .

[0037] Among them, the solid particles of calcium chloride have strong hygroscopicity and can effectively absorb moisture in the air intake pipe 21, which helps to reduce the water vapor content in the combustible gas and improve the purity of the gas. The pure gas can more accurately reflect its actual concentration, thereby improving the detection accuracy of the detector body 1; secondly, by installing a drying box 26 outside the air intake pipe 21, the moisture in the gas can be removed in advance, thereby protecting the components inside the detector body 1 from damage and extending the service life of the detector body 1.

[0038] In some embodiments, a power source body 31 is installed inside the detector body 1 , a controller 35 is installed on the outer surface of the detector body 1 , and the resistor 34 is electrically connected to the power source body 31 and the controller 35 through a wire 32 .

[0039] Among them, the controller 35 model is QB2000N. The controller 35 is electrically connected to the power supply body 31 and the resistor 34 in series with a platinum wire 335 through a wire 32. It can receive and process the bridge signal built between the resistor 34 and the platinum wire 335 in real time. According to the change of the signal, the controller 35 can accurately control the alarm and electrical signal data functions of the detector to ensure that the changes in the concentration of combustible gas can be paid attention to in time.

[0040] In some embodiments, the auxiliary mechanism 33 includes a conductive column 339, a first conductive plate 331 and a second conductive plate 334 are electrically connected in the middle of the wire 32, and a spring 332 is installed between the first conductive plate 331 and the second conductive plate 334, the conductive column 339 is slidably connected inside the first conductive plate 331 and the second conductive plate 334, and limit baffles 333 are provided on the surfaces of the first conductive plate 331 and the second conductive plate 334 that are close to each other, and a platinum wire 335 is inserted inside the conductive column 339, and three platinum wires 335 are provided.

[0041] Among them, the platinum wire 335 is inserted and installed inside the detachable conductive column 339. In actual application, the platinum wire 335 may be damaged or its performance may be degraded due to long-term use or exposure to harsh environments such as high temperature, corrosion, etc. At this time, the platinum wire 335 can be directly replaced. When the platinum wire 335 is broken or damaged, it is only necessary to simply disassemble the conductive column 339 to replace the new platinum wire 335. There is no need to perform large-scale disassembly or repair of the entire sensor circuit, thereby reducing maintenance costs and time; and platinum wires 335 of different materials, specifications or performances can be selected for replacement according to different detection requirements to meet the requirements of different gas concentration detection.

[0042] In some embodiments, a support frame 37 is installed inside the detector body 1, a rubber sleeve 36 is arranged between the support frame 37 and the detector body 1, a support plate 336 is installed between the support frame 37 and the conductive column 339, and the cross-section of the support plate 336 is arc-shaped, and the platinum wire 335 slides in the top groove of the support plate 336.

[0043] Among them, the support plate 336 can position the platinum wire 335, so that the platinum wire 335 can be stably installed inside the conductive column 339. The arc-shaped support plate 336 design helps the uniform diffusion and flow of the gas, so that the combustible gas can more fully contact the platinum wire 335, thereby improving the accuracy and sensitivity of detection.

[0044] In some embodiments, a base 338 is connected to the free end of the platinum wire 335 , and a sealing plug 337 is installed on the surface of the platinum wire 335 located inside the support frame 37 .

[0045] Among them, since the detection of combustible gas concentration is based on the change in the resistance 34 value of the platinum wire 335, the physical state of the platinum wire 335 has a direct impact on its resistance 34 value. Therefore, the platinum wire 335 can be stabilized by the sealing plug 337 to prevent the platinum wire 335 from flameless combustion and causing the platinum wire 335 to shrink.

[0046] In some embodiments, a pressure relief pipe 512 is disposed inside the detector body 1 near the platinum wire 335, a pressure relief valve is disposed on the pressure relief pipe 512, a pressure gauge 511 is installed on the outer surface of the detector body 1, and the pressure relief valve is electrically connected to the pressure gauge 511 through the power supply body 31.

[0047] In particular, when the concentration of combustible gas is extremely high and the platinum wire 335 is burning flamelessly, a large amount of heat flow will be released. At this time, the internal pressure of the detector body 1 is too high, which may cause an explosion hazard. The setting of the pressure relief pipe 512 can reduce this risk because it allows part of the gas to escape when the pressure rises to a certain level, thereby reducing the risk of explosion.

[0048] In some embodiments, an oxygen supply mechanism 4 is provided inside the detection component 3, and the oxygen supply mechanism 4 includes an oxygen tank 43. The oxygen tank 43 is opened inside the detector body 1, and the top of the oxygen tank 43 is connected to an oxygen supply pipe 44. The surface of the oxygen tank 43 near the platinum wire 335 is connected to a connecting pipe 42, and an electronic valve is installed on the connecting pipe 42. A combustible gas alarm probe 41 is installed inside the detector body 1 near the platinum wire 335, and the combustible gas alarm probe 41 is electrically connected to the electronic valve and the alarm 6 through the controller 35.

[0049] Among them, the oxygen supply channel ensures the oxygen supply required for the full combustion of the combustible gas and the platinum wire 335, avoiding the problem of incomplete combustion due to insufficient oxygen, thereby improving the detection accuracy; the stable oxygen supply makes the oxidation reaction of the platinum wire 335 more stable, reduces the detection error caused by fluctuations in oxygen concentration, and enhances the detection stability.

[0050] In some embodiments, a protective mechanism 5 is provided inside the detector body 1, and the protective mechanism 5 includes activated carbon crushed 52. A groove is opened inside the detector body 1, and a second protective net 53 is installed inside the groove. The activated carbon crushed 52 is stacked on one side of the second protective net 53, and the groove on the other side of the second protective net 53 is connected to the space where the platinum wire 335 is located, and an exhaust hole 54 is provided, and a top plate 51 is installed near the top of the activated carbon crushed 52 of the detector body 1.

[0051] When the platinum wire 335 fails to burn completely during the combustion process, some metal oxides or other compounds will be produced. These compounds have different chemical properties and toxicity at room temperature, and will cause secondary harm to the environment when emitted into the air. The activated carbon fragments 52 have an extremely high specific surface area due to their porous structure, which enables them to adsorb a large amount of harmful gas molecules. Therefore, after the platinum wire 335 is burned, the activated carbon fragments 52 can absorb the toxicity as much as possible, thereby improving the overall environmental protection effect.

[0052] In some embodiments, a cavity 59 is opened inside the detector body 1 near the groove, and the bottom end of the cavity 59 is connected to the space where the platinum wire 335 is located. A piston 58 is slidably installed inside the cavity 59, and an airbag 57 is installed on the surface of the piston 58 near the platinum wire 335. A movable plug 55 is arranged inside the exhaust hole 54, and a fixed plate 56 is installed on the top of the movable plug 55. A fixed rod 510 is installed between the fixed plate 56 and the piston 58.

[0053] Among them, a piston 58 and an airbag 57 are arranged in the space where the platinum wire 335 and the activated carbon are located. The airbag 57 is made of heat-sensitive material and can expand rapidly under the action of the heat flow released by the combustion of the platinum wire 335. The expansion process of the airbag 57 has a certain buffering effect, which can reduce the impact of high temperature on other parts inside the detector body 1; when the heat flow released by the combustion of the platinum wire 335 is too large, the airbag 57 expands due to the heat and pushes the piston 58 to move. When the piston 58 moves to a certain extent, it can connect the space where the platinum wire 335 is located with the space where the activated carbon is located, thereby realizing further adsorption of harmful substances and gases, which not only improves the safety of the detector, but also reduces the pollution to the environment.

[0054] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.

Claims

1. A gas concentration detection mechanism for a combustible gas alarm, comprising a detector body (1), characterized in that: A detection component (3) having a resistor (34) is arranged inside the detection instrument body (1); the resistor (34) is installed inside the detection component (3); an auxiliary mechanism (33) having a platinum wire (335) is arranged at one end of the resistor (34); the platinum wire (335) is connected in series with the resistor (34); An air intake mechanism (2) having an air intake pipe (21) is provided on one side of the detection component (3); the air intake pipe (21) is installed on the detection component (3) near the platinum wire (335); a movable plate (24) is installed inside the air intake pipe (21); a driving motor (23) is installed on the outer surface of the movable plate (24); a spiral impeller (22) is fixedly installed on the output shaft of the driving motor (23); and a plurality of air flow holes are opened on the outer surface of the spiral impeller (22); A tapered hole (25) is provided inside the movable plate (24), the large diameter end of the tapered hole (25) is close to the platinum wire (335), and the small diameter end of the tapered hole (25) is close to the spiral impeller (22).

2. The gas concentration detection mechanism of the combustible gas alarm according to claim 1 is characterized in that: The outer surface of the air inlet pipe (21) is connected to a drying box (26) containing solid calcium chloride particles, and a first protective net (27) is installed on the surface of the drying box (26) close to the inner wall of the air inlet pipe (21).

3. The gas concentration detection mechanism of the combustible gas alarm according to claim 1 is characterized in that: A power source body (31) is installed inside the detector body (1), a controller (35) is installed on the outer surface of the detector body (1), and the resistor (34) is electrically connected to the power source body (31) and the controller (35) respectively through a wire (32); The auxiliary mechanism (33) comprises a conductive column (339), a first conductive plate (331) and a second conductive plate (334) are electrically connected in the middle of the conductive wire (32), and a spring (332) is installed between the first conductive plate (331) and the second conductive plate (334), the conductive column (339) is slidably connected inside the first conductive plate (331) and the second conductive plate (334), and a limit stopper (333) is provided on surfaces of the first conductive plate (331) and the second conductive plate (334) that are close to each other, and the platinum wire (335) is inserted inside the conductive column (339), and three platinum wires (335) are provided.

4. The gas concentration detection mechanism of the combustible gas alarm according to claim 3 is characterized in that: A support frame (37) is installed inside the detector body (1), a rubber sleeve (36) is arranged between the support frame (37) and the detector body (1), a support plate (336) is installed between the support frame (37) and the conductive column (339), and the cross section of the support plate (336) is arc-shaped, and the platinum wire (335) slides at the top groove of the support plate (336); The free end of the platinum wire (335) is connected to a base (338), and a sealing plug (337) is installed on the surface of the platinum wire (335) located inside the support frame (37).

5. The gas concentration detection mechanism of the combustible gas alarm according to claim 3 is characterized in that: A pressure relief pipe (512) is arranged inside the detector body (1) near the platinum wire (335), and a pressure relief valve is arranged on the pressure relief pipe (512). A pressure gauge (511) is installed on the outer surface of the detector body (1), and the pressure relief valve is electrically connected to the pressure gauge (511) through the power supply body (31).

6. The gas concentration detection mechanism of the combustible gas alarm according to claim 1 is characterized in that: An oxygen supply mechanism (4) is arranged inside the detection component (3), and the oxygen supply mechanism (4) includes an oxygen chamber (43). The oxygen chamber (43) is opened inside the detector body (1), and the top of the oxygen chamber (43) is connected to an oxygen supply pipeline (44). A connecting pipe (42) is connected to the surface of the oxygen chamber (43) near the platinum wire (335), and an electronic valve is installed on the connecting pipe (42). A combustible gas alarm probe (41) is installed inside the detector body (1) near the platinum wire (335), and the combustible gas alarm probe (41) is electrically connected to the electronic valve and the alarm (6) through a controller (35).

7. The gas concentration detection mechanism of the combustible gas alarm according to claim 1 is characterized in that: A protective mechanism (5) is provided inside the detector body (1), and the protective mechanism (5) includes activated carbon fragments (52). A groove is provided inside the detector body (1), and a second protective net (53) is installed inside the groove. The activated carbon fragments (52) are stacked on one side of the second protective net (53), and an exhaust hole (54) is provided in the groove on the other side of the second protective net (53) in communication with the space where the platinum wire (335) is located, and a top plate (51) is installed near the top of the activated carbon fragments (52) on the detector body (1); The detector body (1) is provided with a cavity (59) near the groove, and the bottom end of the cavity (59) is connected to the space where the platinum wire (335) is located. A piston (58) is slidably installed inside the cavity (59), and an air bag (57) is installed on the surface of the piston (58) near the platinum wire (335). A movable plug (55) is arranged inside the exhaust hole (54), and a fixed plate (56) is installed on the top of the movable plug (55), and a fixed rod (510) is installed between the fixed plate (56) and the piston (58).

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