Small high-concentration VOCs gas detection system

Abstract

The utility model discloses a small-sized high-concentration VOCs (volatile organic compounds) gas detection system which comprises a self-adaptive sample gas path, a self-adaptive air path, a hydrogen gas path and an FID, wherein the self-adaptive sample gas path is used for providing a detected sample / sample gas with stable flow for the FID; the self-adaptive air path is used for providing oxygen for the combustion of the FID; the hydrogen gas path is used for providing hydrogen with stable flow for the combustion of the FID; according to the utility model, by designing a new self-adaptive air path, high-concentration VOCs gas can be measured without independently providing oxygen, the FID is prevented from flameout when the concentration of the measured gas is too high, parts such as an oxygen tank do not need to be carried in the actual use process, and therefore, the whole system is simple in structure and low in cost. The device is small in size, portable and simpler to operate through arrangement of internal devices, meanwhile, the flow stability of each gas path can be ensured through a closed-loop gas supply system (a self-adaptive sample gas path and a self-adaptive air path), and the detection accuracy is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to portable total hydrocarbon detection equipment field, specifically is high concentration VOCs gas detection system. BACKGROUND

[0002] In the environmental monitoring process, the VOCs gas in the environment atmosphere is detected, in the prior art, the gas under the environment with high concentration VOCs needs to be detected, the existing equipment or device provides sample gas, hydrogen gas to FID in addition, oxygen needs to be provided separately, so that the FID is extinguished due to the too high concentration of sample gas and the low oxygen content, cannot operate, the oxygen tank needs to be carried in the existing equipment, not only bulky, heavy, inconvenient to carry, but also not conducive to the miniaturization of the instrument, and the device is relatively complex, the cost is higher, the portable requirement cannot be realized, so it is necessary to find new ways or methods to solve part or all of the problems. SUMMARY

[0003] Therefore, the utility model mainly aims at overcoming at least one of the above defects in the prior art when detecting the gas under the environment with high concentration VOCs.

[0004] The utility model provides a small high concentration VOCs gas detection system, including the self -adaptation sample gas gas path of the measured sample / sample gas of FID provides stable flow, the self -adaptation air gas path of the oxygen of FID combustion provides, the hydrogen gas gas path of the stable flow hydrogen of FID combustion provides, FID;

[0005] The self -adaptation sample gas gas path includes first sample gas inlet, the first filter of the first sample gas inlet rear side is connected, the first diaphragm pump of the first filter rear side is connected, the first throttling valve for discharging excess gas is connected in parallel in the first diaphragm pump rear side, and three gas paths are formed, the first gas resistance of FID rear side is connected, and the first pressure sensor is connected;

[0006] The self -adaptation air gas path includes second sample gas inlet, the second filter of the second sample gas inlet rear side is connected, the second diaphragm pump of the second filter rear side is connected, the second pressure sensor is connected in parallel in the second diaphragm pump rear side, and two gas paths are formed, the second gas resistance of FID rear side is connected;

[0007] The hydrogen gas gas path includes one -way inflation valve, the high -pressure gas cylinder of the one -way inflation valve rear side is connected, the diaphragm pressure regulating valve of the high -pressure gas cylinder rear side is connected, the diaphragm pressure regulating valve rear side forms three roads, the first road is connected third pressure sensor, the second road is connected first normally closed ultra -micro electromagnetic valve group, the first normally closed ultra -micro electromagnetic valve group is connected the FID, the third road is connected second normally closed ultra -micro electromagnetic valve group, the second normally closed ultra -micro electromagnetic valve group rear side is connected third gas resistance, and the third gas resistance rear end is connected the FID.

[0008] According to the prior art, when detecting the gas in the environment with high concentration VOCs, the prior art also needs to separately provide oxygen to avoid the FID from being extinguished due to lack of oxygen, and since the oxygen needs to be separately provided, the oxygen tank needs to be carried, which is large in size, heavy, inconvenient to carry, and not conducive to miniaturization of the instrument, and the device is relatively complex, the cost is high, and the portable requirement cannot be met; the utility model discloses a small high-concentration VOCs gas detection system, which is designed to be self-adaptive to air, so that high-concentration VOCs gas can be measured without separately providing oxygen, and the FID will not be extinguished when the concentration of the measured gas is too high, so that the oxygen tank and other components do not need to be carried in the actual use process, so that the overall system structure is simple, and the internal device arrangement is further miniaturized, portable, and simple to operate, and the closed-loop gas supply system (self-adaptive sample gas path and self-adaptive air path) can ensure the flow stability of each gas path and improve the detection accuracy.

[0009] The adaptive sample gas path operation mode and principle are as follows: under the action of the first diaphragm pump, the sample gas passes through the first filter and the first diaphragm pump in turn, and then the gas is divided into four paths, the first path flows into the FID through the first gas resistance, the second path flows into the first pressure sensor, and the third path is discharged through the first throttle valve. This sampling system can discharge excess gas through the first throttle valve and obtain a stable flow of sample gas at the first gas resistance; as the number of particles of the filter membrane increases, the speed of the first diaphragm pump motor is adjusted through the first pressure sensor, so that the gas in the gas path is maintained within a stable range, and the system structure is simple and convenient for miniaturization, and the flow of the gas is controllable.

[0010] The adaptive air path operation mode and principle are as follows: under the action of the second diaphragm pump, the measured gas (containing high-concentration non-methane total hydrocarbon) passes through the second filter and the second diaphragm pump in turn to obtain air, and then the air is divided into two paths, the first path flows into the FID through the second gas resistance, and the second path flows into the second pressure sensor. This sampling system obtains a stable flow of air at the second gas resistance; as the number of particles of the metal sintered filter increases, the speed of the second diaphragm pump motor is adjusted through the second pressure sensor, so that the gas in the gas path is maintained within a stable range, and the air filtration system structure is also simple and convenient for miniaturization, and the flow of the gas is controllable.

[0011] The hydrogen gas path operation mode and principle are as follows: the gas in the gas source is stored into the high-pressure gas cylinder through the one-way inflation valve, the diaphragm pressure regulating valve is adjusted, the outlet pressure is adjusted to the required pressure value, the gas is output to the first normally closed ultra-micro electromagnetic valve and the second normally closed ultra-micro electromagnetic valve, the gas in the first normally closed ultra-micro electromagnetic valve is directly transmitted to the FID, the gas in the second normally closed ultra-micro electromagnetic valve is transmitted to the FID through the third gas resistance, when the FID is ignited, a large amount of hydrogen gas is required, the first normally closed ultra-micro electromagnetic valve and the second normally closed ultra-micro electromagnetic valve are opened at the same time, when the FID runs stably and requires a small amount of gas, the first normally closed ultra-micro electromagnetic valve is closed, the second normally closed ultra-micro electromagnetic valve is opened, and the second normally closed ultra-micro electromagnetic valve outputs stable small-flow gas through the third gas resistance. The hydrogen gas path system has simple structure and convenient operation, can adjust the size of the gas cylinder according to the use requirements of the detection equipment, is convenient for miniaturization, is not sensitive to changes of environmental temperature and pressure, has fast response speed, can realize rapid gas flow conversion, and can realize micro-flow and high-speed precise control through the third gas resistance.

[0012] In addition, the small high-concentration VOCs gas detection system has the following additional technical features.

[0013] Further, the first filter for filtering sample gas comprises a first filter core, and the first filter core is made of porous polytetrafluoroethylene material.

[0014] Further, the porous polytetrafluoroethylene material has a pore size of 0.4-0.5 microns.

[0015] Preferably, the porous polytetrafluoroethylene material has a pore size of 0.45 microns.

[0016] Further, the second filter for filtering sample gas comprises a second filter core, and the second filter core is made of primary efficiency filter cotton, molecular sieve, activated carbon or metal sintered filter core, and the second filter core can filter dust particles, VOCs gas and water vapor with a size of 5 microns or above.

[0017] Further, one end of the one-way inflation valve is directly connected with the high-pressure gas cylinder, and the other end is a high-pressure quick connector connected with the quick connector of the gas source.

[0018] The first diaphragm pump is responsible for collecting and transporting sample gas, and the size of the sample gas flow is positively correlated with the size of the current; the first throttle valve is a valve for realizing flow regulation and control by changing the size of the valve port; the knob on the throttle valve is adjusted to make the pressure inside the four-way gas distribution block reach a set value; the gas resistance is used for stabilizing the outlet flow; the first and second pressure sensors are used for measuring the pressure inside the sample gas channel and the air channel respectively, and reversely control the first and second diaphragm pumps; when the pressure is reduced, the motor speed of the first and second diaphragm pumps is increased to increase the air intake; when the pressure is higher than the set value, the motor speed of the first and second diaphragm pumps is reduced to reduce the air intake; the diaphragm pressure regulating valve is used for adjusting the gradually reduced pressure of the gas cylinder to output a pressure maintained in a stable range; the third pressure sensor is used for detecting the hydrogen outlet pressure; and the normally closed ultra-micro electromagnetic valve realizes the opening and closing of the fluid channel by opening and closing actions, so as to control the flow of the fluid.

[0019] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1 is a structural schematic diagram of a small high-concentration VOCs gas detection system in the embodiments of the present application;

[0022] Figure 2 is a schematic diagram of the overall appearance structure of a small high-concentration VOCs gas detection system in the embodiments of the present application;

[0023] Figure 3 is a schematic diagram of the internal structure in the embodiments of the present application;

[0024] Figure 4 is a schematic diagram of the upper cover plate structure in the embodiments of the present application;

[0025] Figure 5 is a schematic diagram of the overall framework of the system in the embodiments of the present application.

[0026] Wherein, 1 adaptive sample gas path, 1-1 first sample gas inlet, 1-2 first filter, 1-3 first diaphragm pump, 1-4 first throttle valve, 1-5 first air resistance, 1-6 first pressure sensor, 2 adaptive air path, 2-1 second sample gas inlet, 2-2 second filter, 2-3 second diaphragm pump, 2-4 second pressure sensor, 2-5 second air resistance, 3 hydrogen gas path, 3-1, one-way inflation valve, 3-2 high-pressure gas cylinder, 3-3 diaphragm pressure regulating valve, 3-4 third pressure sensor, 3-5 first normally closed ultra-micro electromagnetic valve, 3-6 second normally closed ultra-micro electromagnetic valve 3-7 third air resistance;

[0027] A main housing module, A1-1 battery, A1-2 air filter, A1-3 control board PCB assembly, A1-4 gas shunt assembly, A1-5 filter, A1-6 sample gas diaphragm pump, A1-7 diaphragm pump fixed buffer frame, A1-8 air diaphragm pump, A1-9 pressure relief valve, A1-10 FID assembly, A1-11 hydrogen pressure regulating assembly, A1-12 high-pressure hydrogen storage steel cylinder assembly, A1-13 electromagnetic reversing valve assembly, A1-14 sample gas inlet quick plug street, A1-15 lower housing A1-16 upper and lower housing sealing rubber strip;

[0028] B upper housing module, B2-1 upper housing, B2-2 display screen assembly, B2-3 key assembly;

[0029] C handle module, C3-1 key assembly, C3-2 display screen assembly, C3-3 handle data transmission line, C3-4 sample gas inlet pipe, C3-5 handle housing assembly, C3-6 filter, C3-7 sampling steel pipe. DETAILED DESCRIPTION

[0030] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be interpreted as a limitation of the present application.

[0031] In the description of the present application, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "back", "inner", "outer", "horizontal", "vertical" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0032] In the description of the utility model, it is necessary to explain that, unless there are explicit provisions and limitations, the terms "coupling", "communication", "connection", "connection", "fitting" should be understood broadly, for example, it can be fixedly connected, integrally connected, or it can be detachably connected, it can be the communication inside two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium, "fitting" can be the fitting of surface to surface, or the fitting of point to surface or line to surface, also including the fitting of hole shaft, for ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0033] The utility model discloses the utility model concept as follows, provide a kind of small high concentration VOCs gas detection system, by design new self-adapting air gas path, so that it can measure high concentration VOCs gas without separately providing oxygen, avoid the concentration of measured gas too high, FID will not be extinguished, so that in actual use process, there is no need to carry oxygen tank and other components, so that the overall system structure is simple, and by internal device arrangement and then miniaturization, portable, operation is more simple, simultaneously, by closed loop gas supply system (self-adapting sample gas path, self-adapting air gas path), the flow stability of each gas path can be ensured, improve detection accuracy.

[0034] A small high concentration VOCs gas detection system of the utility model will be described below with reference to the drawings, wherein Figure 1 It is the structure schematic diagram of a kind of small high concentration VOCs gas detection system in the utility model embodiment; Figure 2 It is the overall appearance structure schematic diagram of a kind of small high concentration VOCs gas detection system in the utility model embodiment; Figure 3 It is the internal structure schematic diagram in the utility model embodiment; Figure 4 It is the upper cover plate structure schematic diagram in the utility model embodiment.

[0035] As Figures 1 to 4 Indicated, according to the embodiment of the utility model, the small high concentration VOCs gas detection system includes the self-adapting sample gas path of the measured sample / sample gas for providing stable flow for FID, the self-adapting air gas path for providing oxygen for FID combustion, the hydrogen gas path for providing stable flow hydrogen for FID combustion, FID;

[0036] The self-adapting sample gas path includes first sample gas inlet, the first filter connected with the rear side of the first sample gas inlet, the first diaphragm pump connected with the rear side of the first filter, the first throttling valve for discharging excess gas connected in parallel at the rear side of the first diaphragm pump, and forming three-way gas path, the first gas resistance connected with the rear side of FID, the first pressure sensor;

[0037] The adaptive air gas path comprises a second sample gas inlet, a second filter connected to the rear side of the second sample gas inlet, a second diaphragm pump connected to the rear side of the second filter, a second pressure sensor connected in parallel to the rear side of the second diaphragm pump and forming a two-way gas path, and a second gas resistance connected to the rear side of the FID;

[0038] The hydrogen gas path comprises a one-way inflation valve, a high-pressure gas cylinder connected to the rear side of the one-way inflation valve, and a diaphragm pressure regulating valve connected to the rear side of the high-pressure gas cylinder. The diaphragm pressure regulating valve forms three paths, the first path is connected to a third pressure sensor, the second path is connected to a first normally closed ultra-micro electromagnetic valve group, the first normally closed ultra-micro electromagnetic valve group is connected to the FID, and the third path is connected to a second normally closed ultra-micro electromagnetic valve group. The rear side of the second normally closed ultra-micro electromagnetic valve group is connected to a third gas resistance, and the rear end of the third gas resistance is connected to the FID.

[0039] The adaptive sample gas path operating mode and principle are as follows: under the action of the first diaphragm pump, the sample gas passes through the first filter and the first diaphragm pump in sequence, and then the gas is divided into four paths, the first path flows into the FID through the first gas resistance, the second path flows into the first pressure sensor, and the third path is discharged through the first throttle valve. This sampling system can discharge excess gas through the first throttle valve and obtain a stable flow of sample gas at the first gas resistance; as the number of particles on the filter membrane increases, the speed of the first diaphragm pump motor is adjusted through the first pressure sensor, so that the gas in the gas path is maintained within a stable range. This system is simple and easy to miniaturize, and the flow of gas is controllable.

[0040] The adaptive air gas path operating mode and principle are as follows: under the action of the second diaphragm pump, the measured gas (containing high-concentration non-methane total hydrocarbon) passes through the second filter and the second diaphragm pump in sequence to obtain air, and then the air is divided into two paths, the first path flows into the FID through the second gas resistance, and the second path flows into the second pressure sensor. This sampling system obtains a stable flow of air at the second gas resistance; as the number of particles on the metal sintered filter increases, the speed of the second diaphragm pump motor is adjusted through the second pressure sensor, so that the gas in the gas path is maintained within a stable range. This air filtration system is also simple and easy to miniaturize, and the flow of gas is controllable.

[0041] The hydrogen gas path operation mode and principle are as follows: the gas in the gas source is stored into the high-pressure gas cylinder through the one-way inflation valve, the diaphragm pressure regulating valve is adjusted, the outlet pressure is adjusted to the required pressure value, the gas is output into the first normally closed ultra-micro electromagnetic valve and the second normally closed ultra-micro electromagnetic valve, the gas in the first normally closed ultra-micro electromagnetic valve is directly transmitted to the FID, the gas in the second normally closed ultra-micro electromagnetic valve is transmitted to the FID after passing through the third gas resistance, a large amount of hydrogen gas is required when the FID is ignited, and the first normally closed ultra-micro electromagnetic valve and the second normally closed ultra-micro electromagnetic valve are simultaneously opened; when the FID runs stably and requires a small amount of gas, the first normally closed ultra-micro electromagnetic valve is closed, and the second normally closed ultra-micro electromagnetic valve is opened, and the second normally closed ultra-micro electromagnetic valve outputs stable small-flow gas through the third gas resistance. The hydrogen gas path system has simple structure and convenient operation, the size of the gas cylinder can be adjusted according to the use requirements of the detection equipment, miniaturization is facilitated, the system is not sensitive to changes in environmental temperature and pressure, and the response speed is fast, rapid gas flow conversion can be performed, and micro-flow and high-speed precise control can be realized through the third gas resistance.

[0042] According to the embodiment of the present application, the first filter for filtering sample gas comprises a first filter element, and the first filter element is made of porous polytetrafluoroethylene material.

[0043] Further, the porous polytetrafluoroethylene material has a pore size of 0.4-0.5 microns.

[0044] Preferably, the porous polytetrafluoroethylene material has a pore size of 0.45 microns.

[0045] According to the embodiment of the present application, the second filter for filtering sample gas comprises a second filter element, and the second filter element is made of primary efficiency filter cotton, molecular sieve, activated carbon or metal sintered filter element, and the second filter element can filter dust particles, VOCs gas and water vapor with a size of more than 5 microns.

[0046] According to the embodiment of the present application, one end of the one-way inflation valve is directly connected with the high-pressure gas cylinder, and the other end is a high-pressure quick connector connected with the gas source.

[0047] According to one embodiment of the present application, the small high-concentration VOCs gas detection system comprises a main shell module composed of upper and lower shells, and a handle module connected with the main shell module.

[0048] The lower shell comprises a battery, an air filter, a control board PCB assembly, a gas shunt assembly, a filter, a sample gas diaphragm pump, a diaphragm pump fixing buffer frame, an air diaphragm pump, a pressure relief valve, an FID assembly, a hydrogen pressure regulating assembly, a high-pressure hydrogen storage steel cylinder assembly, an electromagnetic reversing valve assembly, a sample gas inlet quick connector, a lower shell, upper and lower shell sealing rubber strips, and the like, and the connection relationship and spatial position structure thereof are as follows: Figure 3As shown, in the internal design, on the one hand, relevant equipment meeting the design requirements is adopted, and on the other hand, miniaturization design is carried out according to actual requirements in the design process.

[0049] Meanwhile, the upper shell further comprises a display screen assembly, a key assembly and the like, and components for human-computer interaction.

[0050] The handle module comprises a key assembly, a display screen assembly, a handle data transmission line, a sample gas inlet pipe, a handle shell assembly, a filter, a sampling steel pipe and the like, and the connection relationship and spatial position structure thereof are shown as follows. Figure 5

[0051] Any reference to "one embodiment", "an embodiment", "certain embodiments", etc., means that a particular element, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" or "in an embodiment" in various places in the specification are not necessarily referring to the same embodiment. Further, when a particular element, structure, or characteristic is described in connection with any embodiment, it is submitted that implementation of such an element, structure, or characteristic is within the purview and scope of one of ordinary skill in the art.

[0052] Although the specific implementation of the application has been described in detail with reference to a plurality of illustrative embodiments of the application, it must be understood that those skilled in the art can design a plurality of other improvements and embodiments, which will fall within the spirit and scope of the principles of the application. Specifically, within the scope of the foregoing disclosure, drawings and claims, reasonable variations and improvements can be made in the arrangement of parts and / or dependent combination layout without departing from the spirit of the application. In addition to variations and improvements in parts and / or layout, the scope thereof is defined by the appended claims and their equivalents.​

Claims

1. A small high concentration VOCs gas detection system characterized in that , including an adaptive sample gas path for providing a stable flow of the measured sample / gas for the FID, an adaptive air path for providing oxygen for the FID combustion, a hydrogen gas path for providing a stable flow of hydrogen gas for the FID combustion, and the FID; The adaptive sample gas path comprises a first sample gas inlet, a first filter connected to the rear side of the first sample gas inlet, a first diaphragm pump connected to the rear side of the first filter, a first throttling valve connected in parallel to the rear side of the first diaphragm pump and forming a three-way gas path, a first gas resistance connected to the rear side of the FID, and a first pressure sensor; The adaptive air path comprises a second sample gas inlet, a second filter connected to the rear side of the second sample gas inlet, a second diaphragm pump connected to the rear side of the second filter, a second pressure sensor connected in parallel to the rear side of the second diaphragm pump and forming a two-way gas path, and a second gas resistance connected to the rear side of the FID; The hydrogen gas path comprises a one-way inflation valve, a high-pressure gas cylinder connected to the rear side of the one-way inflation valve, and a diaphragm pressure regulating valve connected to the rear side of the high-pressure gas cylinder, wherein the rear side of the diaphragm pressure regulating valve forms three paths, a first path connected to a third pressure sensor, a second path connected to a first normally closed ultra-micro electromagnetic valve group, the first normally closed ultra-micro electromagnetic valve group connected to the FID, and a third path connected to a second normally closed ultra-micro electromagnetic valve group, the rear side of the second normally closed ultra-micro electromagnetic valve group connected to a third gas resistance, and the rear end of the third gas resistance connected to the FID.

2. The small high-concentration VOCs gas detection system according to claim 1, wherein, The first filter for filtering sample gas comprises a first filter core made of porous polytetrafluoroethylene material.

3. The small high-concentration VOCs gas detection system according to claim 2, wherein, The porous polytetrafluoroethylene material has a pore size of 0.4-0.5 microns.

4. The small high-concentration VOCs gas detection system according to claim 3, wherein, The porous polytetrafluoroethylene material has a pore size of 0.45 microns.

5. The small high-concentration VOCs gas detection system according to claim 1, wherein, The second filter for filtering sample gas comprises a second filter core made of primary efficiency filter cotton, molecular sieve, activated carbon, or metal sintered filter core.

6. The small high-concentration VOCs gas detection system according to claim 1, wherein, One end of the one-way inflation valve is directly connected to the high-pressure gas cylinder, and the other end is a high-pressure quick connector connected to the gas source.

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