Particulate matter detection device and particulate matter detection method

Abstract

The invention discloses a particulate matter detection device which comprises a box body, and a quantitative gas taking mechanism, a water vapor removal mechanism, a gas particle removal and storage mechanism, a to-be-detected gas temporary storage mechanism and a gas particle analysis and detection mechanism which are arranged in the box body, the quantitative gas taking mechanism comprises a quantitative barrel, a push-down piston, a push-up piston and a first push cylinder; the water vapor removal mechanism comprises a water vapor discharge box, an S-shaped permeation tube and a gas supply long box; the gas particle removal storage mechanism comprises a gas filter box and a clean gas storage box; the to-be-detected gas temporary storage mechanism comprises a temporary storage box and an extrusion piston; the particle analysis and detection mechanism comprises a particle content analyzer and an impurity-free gas analyzer, and the detection method comprises the following steps: firstly, extracting quantitative to-be-detected gas, removing water vapor, and carrying out reference analysis. The balancing gas is diluted in the temporary storage box, so that the particle content in the gas is very close to the actual particle content, the environmental gas is used for contrastive analysis in the measurement process, and the precision of the analyzed particle content is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of particle content detection in air, and in particular to a particle detection device and a particle detection method. Background Art

[0002] The pollution of tiny particles in the air is the main cause of haze weather, and it also affects human health. Therefore, the concentration of particles in the air is one of the important criteria for judging air quality. During the production process of the factory, the air inside the factory building is different from that outside the factory building. It will be affected by the equipment and contain other impurities. Due to the different gases, the attenuation of beta rays when passing through the gas is not only affected by the particles in the gas, but also by the water vapor in the gas and the gas composition and content in the gas. When detecting the content of particles in the gas, it cannot only consider the attenuation rate, but also consider the gas reference attenuation rate and the attenuation rate after removing water vapor. Moreover, the existing detection of the effect of particles in the gas on beta rays cannot analyze the particle size distribution of particles in the gas and the content ratio within the distribution area, and the analysis accuracy and degree are not high. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one purpose of the present invention is to provide a particle detection device and a particle detection method, which solves the problem that it is difficult to distinguish the influence of water vapor in the air and gas components and concentrations in different environments on particle analysis errors, resulting in low analysis accuracy.

[0004] A particle detection device according to the present invention comprises a box body and a quantitative gas extraction mechanism, a water vapor removal mechanism, a gas particle removal storage mechanism, a temporary storage mechanism for a gas to be tested, and a gas particle analysis and detection mechanism arranged in the box body;

[0005] The quantitative air extraction mechanism is arranged on the left side of the box body, and the quantitative air extraction mechanism comprises a quantitative cylinder, a push-down piston, an upper piston and a first pushing cylinder. When the push-down piston in the quantitative cylinder is at the topmost point in the cylinder, an air inlet pipe for measuring gas is arranged on the side wall of the quantitative cylinder close to the lower surface of the push-down piston, and an electromagnetic valve is arranged in the air inlet pipe. When the push-up piston in the quantitative cylinder is at the bottommost point in the cylinder, an air outlet pipe is arranged on the other side wall of the quantitative cylinder close to the upper surface of the push-up piston, and an electromagnetic valve is arranged in the air outlet pipe. The quantitative cylinder uses a first pushing cylinder to push the push-down piston and the upper piston at the middle position of the top wall and the bottom wall, and the quantitative cylinder is connected to the push-down piston and the upper piston by two limiting movable rods on the top wall and the bottom wall;

[0006] The water vapor removal mechanism includes a water vapor discharge box, a plurality of S-shaped permeation tubes and a long air supply box, the bottom of the long air supply box is connected to the air outlet pipe of the metering cylinder through a connecting pipe, the air inlet ends of the plurality of S-shaped permeation tubes are connected to the inside of the long air supply box from the side wall in a row, the plurality of S-shaped permeation tubes are arranged side by side in the water vapor discharge box, and the air outlet pipes of each S-shaped permeation tube extend from the bottom wall of the water vapor discharge box to the outside, the bottom wall of the water vapor discharge box is provided with a particle-free gas inlet pipe, the top wall is provided with a particle-free gas outlet pipe, and the S-shaped permeation tubes are evenly provided with gas and water vapor holes;

[0007] The gas particle removal storage mechanism includes a gas filter box and a clean gas storage box, a gas filter box is provided at the top right side of the box body, and a clean gas storage box is provided below the gas filter box, the air inlet of the gas filter box is provided on the right side wall of the box body, and the air outlet at the rear side of the gas filter box is connected to the top position of the left side wall of the clean gas storage box through a gas exhaust pipe, an exhaust gas pipe is provided in the middle position of the gas exhaust pipe, an air pump is provided in the upper half section of the exhaust gas pipe position, and an electromagnetic valve is provided in the lower half section, and an electromagnetic valve is provided in the exhaust gas pipe at the position connected to the gas exhaust pipe A magnetic valve, a negative pressure piston movable up and down is provided in the clean gas storage box, the bottom of the clean gas storage box is pushed to move the negative pressure piston by a second pushing cylinder and the lower surface of the negative pressure piston is limited by two limiting rods, the left side wall of the clean gas storage box is connected with the particle-free gas inlet pipe through a first circulation pipe and a circulation fan is provided in the first circulation pipe, the particle-free gas outlet pipe on the water vapor discharge box is extended to the side wall at the air inlet end position of the gas filter box and connected to the inside, the left side wall of the clean gas storage box is connected with the outlet pipe of the metering cylinder through a connecting pipe and a solenoid valve is provided in the connected position;

[0008] The temporary storage mechanism for the gas to be tested includes a temporary storage box and an extrusion piston symmetrically arranged in the temporary storage box, extrusion cylinders are symmetrically arranged on the two side walls of the temporary storage box, and the two extrusion cylinders push the extrusion pistons correspondingly, and two limit slide bars are correspondingly arranged on the outer side walls of the two extrusion cylinders, and the gas outlet ends of the multiple S-shaped permeation tubes are connected to the top wall of the temporary storage box in a row, and two rows of constant pressure tubes are symmetrically arranged on the top wall of the temporary storage box, the bottom end of the constant pressure tube is connected to the temporary storage box, and the top end is closed, and the constant pressure tube is provided with an electromagnetic valve near the bottom end, and uniform gas vents are provided on the tube wall above the electromagnetic valve;

[0009] The particle analysis detection mechanism includes a plurality of particle content analyzers and a plurality of impurity-free gas analyzers. The particle content analyzers have the same structure and function as the impurity-free gas analyzers. The bottom of the temporary storage box is connected to the inlet of the particle content analyzer through a plurality of detection and analysis tubes. The detection and analysis tubes are provided with solenoid valves at the connection position with the bottom of the temporary storage box and at the connection position with the particle content analyzer. The detection and analysis tubes are provided with a branch pipe at the connection position with the particle content analyzer and away from the solenoid valve for a distance, and the branch pipe is provided with a solenoid valve. The right side wall of the clean gas storage box is connected to the impurity-free gas analyzer through a plurality of gas analysis tubes, and the structure, number and position of valves on the gas analysis tubes are the same as those of the particle content analyzer.

[0010] A controller is provided at the top of the box body and a touch panel is provided outside the top wall. The controller is electrically connected to the touch panel and is used to control the electrical appliances in the quantitative gas extraction mechanism, the water vapor removal mechanism, the gas particle removal storage mechanism, the temporary storage mechanism for the gas to be tested and the gas particle analysis and detection mechanism.

[0011] In some embodiments of the present invention, when the push-down piston and the push-up piston of the metering cylinder are at the topmost and bottommost positions in the metering cylinder, the volume of the metering cylinder between the push-down piston and the push-up piston is V1, and when the two extrusion pistons of the temporary storage box are at the two side positions in the temporary storage box, the volume of the temporary storage box between the two extrusion pistons is V2, and the volume of V1 is 2-3% larger than the volume of V2.

[0012] In some other embodiments of the present invention, the particle content analyzer includes a detection tube, a β-ray emitter, a β-ray detector, an air intake adjusting piston and an exhaust fan. The detection tube is provided with a mounting tube near both ends thereof which is connected to the interior of the detection tube and the top of the mounting tube is closed. Both mounting tubes are provided with an ejection cylinder and the ejection cylinders are respectively provided with a β-ray emitter and a β-ray detector. The detection tube is plugged with an air intake adjusting piston. The air inlet end of the detection tube is provided with a particle filter but one of the detection tubes is not provided with a particle filter. The air outlet end of the detection tube is provided with an exhaust fan.

[0013] In some other embodiments of the present invention, the filtration pore sizes of the plurality of particle filters are different, and the filtration pore sizes of the plurality of particle filters are respectively 10 μm, 5 μm and 2.5 μm.

[0014] In other embodiments of the present invention, the gas filter box 6 is filled with a multi-layer cotton mesh for absorbing water vapor and filtering particles.

[0015] In other embodiments of the present invention, heating plates are provided on the outer wall of the metering cylinder and the outer wall of the water vapor exhaust box.

[0016] A particle detection method is provided, using the particle detection device described above for detection, and the specific detection steps are as follows:

[0017] S1: Start the particle detection device. Before starting, the push-up piston in the metering cylinder fits with the push-down piston at the top, and the negative pressure piston in the clean gas storage box is at the top of the clean gas storage box. After starting, the solenoid valve in the air inlet pipe of the metering cylinder is opened, and the solenoid valve in the exhaust air pipe connected to the gas exhaust pipe is opened. The push-up piston is slowly pulled down to the bottom by the first push cylinder, so that the metering cylinder is filled with the gas to be tested. The vacuum pump in the gas exhaust pipe starts to pump air and discharge it from the exhaust air pipe, so that the impurities in the gas filter box are emptied. At this time, the solenoid valve in the air inlet pipe of the metering cylinder is closed, and the solenoid valve in the exhaust air pipe is closed. Then, the solenoid valve in the gas exhaust pipe is opened, and the negative pressure piston in the clean gas storage box is slowly moved down, so that the clean gas storage box is filled with clean gas.

[0018] S2: Open the solenoid valve in the connecting pipe and discharge the clean gas in the clean gas storage box into multiple S-shaped permeation tubes through the air pump in the connecting pipe, and then discharge it into the temporary storage box for ventilation to remove the residual impurities inside. After removing the impurities, close the solenoid valve in the connecting pipe, open the solenoid valve in the air outlet pipe of the metering cylinder, and slowly move the push-down piston downward to transport the gas containing particles into multiple S-shaped permeation tubes and then enter the temporary storage box. In this process, it is also necessary to start the gas in the clean gas storage box to be discharged into the water vapor discharge box, and then enter the gas filter box to take away the water vapor. Due to the two rows of constant pressure pipes It has the effect of deflation but retaining particles. The temporary storage box can be inflated all the time. When the piston is pushed down to the bottom, the gas in the metering cylinder is emptied. At this time, the solenoid valve in the gas outlet pipe of the metering cylinder is closed and the solenoid valve in the connecting pipe is opened at the same time. The clean gas in the clean gas storage box is discharged into multiple S-type permeation tubes through the air pump in the connecting pipe, and then discharged into the temporary storage box, so that the gas containing particles remaining in the S-type permeation tube is completely discharged into the temporary storage box. At this time, the solenoid valve in the connecting pipe and the solenoid valve at the output end of the S-type permeation tube are closed again, and the solenoid valves in the two rows of constant pressure tubes are closed after the air pressure in the temporary storage box is stabilized.

[0019] S3: Open the electromagnetic valve at the connection position between the detection and analysis tube and the temporary storage box and the electromagnetic valve in the branch pipe, and exhaust the impurities in the detection and analysis tube by squeezing two squeezing pistons, then close the electromagnetic valve on the branch pipe, and stop the squeezing piston from moving at the same time. The electromagnetic valve in the branch pipe on the gas analysis tube is also opened, and the impurities are exhausted by the air pump in the gas analysis tube, and then close the electromagnetic valve in the branch pipe on the gas analysis tube, open the electromagnetic valves in the near-end of multiple particle content analyzers and multiple impurity-free gas analyzers, and open the electromagnetic valves in the gas analysis tube and the detection and analysis tube at the same time, and fill the multiple particle content analyzers and multiple impurity-free gas analyzers with gas containing particles and clean gas, respectively, and start the analysis. The impurity-free gas analyzer is used to analyze the effect of the particle-free and water vapor-free gas on the β-ray attenuation rate as a reference, and the particle content analyzer is used to analyze the effect of the particulate matter gas on the β-ray attenuation rate to detect the particle content;

[0020] S4: The controller analyzes the beta ray attenuation rates detected by multiple particle content analyzers and compares the beta ray attenuation rates obtained by the impurity-free gas analyzer to analyze the particle content and the particle size distribution content.

[0021] In some other embodiments of the present invention, the method for using multiple particle content analyzers and multiple impurity-free gas analyzers to detect the effect of gas on the attenuation rate of beta rays is as follows: 1. Gas enters from the air inlet end of the particle content analyzer to push the air inlet regulating piston to move from the air inlet end to the air outlet end so that the gas to be tested fills the detection tube. At this time, the solenoid valve on the branch pipe is opened for 2-3 seconds to make the gas in the detection tube and the outside constant pressure, and then the solenoid valve on the branch pipe is closed; 2. The beta-ray emitter and the beta-ray detector are pushed into the detection tube by the pushing cylinder, and the two are in a relative setting. The beta-ray emitter and the beta-ray detector are started to work, the beta-ray emitter 94 emits beta rays, and the beta-ray detector detects the attenuation rate of beta rays. After the detection, the beta-ray emitter and the beta-ray detector are put away; 3. The solenoid valve in the branch pipe on the detection and analysis tube is opened, and the exhaust fan exhausts air into the detection tube to push the air inlet regulating piston, discharges the measured gas from the branch pipe, and then the solenoid valve in the branch pipe is closed, waiting for the next detection, and the next detection steps are the same as above;

[0022] The detection steps of the impurity-free gas analyzer are the same as those of the particle content analyzer.

[0023] In other embodiments of the present invention, the particle filters provided on the inlet pipe of each particle content analyzer have different filtration apertures, and the filtration apertures of the plurality of particle filters are 10 μm, 5 μm and 2.5 μm respectively, and there is one particle content analyzer inlet pipe without a particle filter;

[0024] After passing through the particle filter with a pore size of 10 μm, the particle size of the particles entering the detection tube is less than 10 μm;

[0025] After passing through the particle filter with a pore size of 5 μm, the particle size of the particles entering the detection tube is less than 5 μm;

[0026] After passing through the particle filter with a pore size of 2.5 μm, the particle size of the particles entering the detection tube is less than 2.5 μm.

[0027] In the present invention, a quantitative amount of gas to be tested is inhaled and the gas to be tested is slowly discharged into a temporary storage box. Before being discharged, water vapor and particles in the gas are first removed by a gas particle removal storage mechanism to obtain clean gas. The clean gas is used to evacuate the internal pipeline of the device and the gas in the temporary storage box to prevent interference. When the gas to be tested is started, it slowly flows from multiple S-shaped permeation tubes into the temporary storage box. During the flow process, water vapor is replaced in the water vapor discharge box to greatly reduce the influence of water vapor in the measured gas on the particle measurement. Then, the gas is diluted and balanced in the temporary storage box so that the particle content in the gas is very close to the actual one, and the concentration error is less than 2%. Then, the particle content is measured, and the ambient gas (not containing particles and water vapor) is used for comparative analysis in the measurement process, and the accuracy of the particle content obtained by analysis is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 This is a schematic diagram of the three-dimensional structure of a particle detection device proposed by the present invention.

[0030] Figure 2 This is a schematic diagram of the internal cross-sectional structure of a particle detection device proposed by the present invention.

[0031] Figure 3 for Figure 2 Enlarged structural diagram at A in the middle.

[0032] Figure 4 This is a schematic diagram of the installation structure of the S-type permeation tube proposed in the present invention.

[0033] Figure 5 This is a schematic diagram of the S-type permeation tube structure proposed by the present invention.

[0034] Figure 6 This is a schematic diagram of the structure of the particle content analyzer proposed in the present invention.

[0035] In the figure: 1, box body; 11, touch panel; 12, handle; 2, metering cylinder; 21, air inlet pipe; 22, push piston; 23, push piston; 24, first push cylinder; 3, air supply box; 31, connecting pipe; 4, water vapor exhaust box; 41, particle-free gas inlet pipe; 42, particle-free gas outlet pipe; 5, S-type permeation tube; 51, water vapor permeation hole; 6, gas filter box; 61, gas exhaust pipe; 611, vacuum pump; 7, dry Clean gas storage box; 71, negative pressure piston; 711, second push cylinder; 72, gas analysis tube; 73, connecting tube; 8, temporary storage box; 81, extrusion piston; 82, constant pressure tube; 83, detection and analysis tube; 831, particle filter; 832, branch pipe; 9, particle content analyzer; 91, detection tube; 92, air intake adjustment piston; 93, beta ray detector; 94, beta ray emitter; 95, exhaust fan; 10, controller. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0037] like Figure 1-6 As shown, a particle detection device comprises a box body 1 and a quantitative gas extraction mechanism, a water vapor removal mechanism, a gas particle removal storage mechanism, a temporary storage mechanism for a gas to be tested, and a gas particle analysis and detection mechanism arranged in the box body 1;

[0038] The quantitative gas extraction mechanism is arranged on the left side of the box body 1, and the quantitative gas extraction mechanism comprises a quantitative cylinder 2, a push-down piston 23, an upward piston 22 and a first pushing cylinder 24. When the push-down piston 23 in the quantitative cylinder 2 is at the topmost point in the cylinder, an air inlet pipe 21 for measuring gas is provided on the side wall of the quantitative cylinder 2 close to the lower surface of the push-down piston 23, and an electromagnetic valve is provided in the air inlet pipe 21. When the push-up piston 22 in the quantitative cylinder 2 is at the bottommost point in the cylinder, an air outlet pipe is provided on the other side wall of the quantitative cylinder 2 close to the upper surface of the push-up piston 22, and an electromagnetic valve is provided in the air outlet pipe. The quantitative cylinder 2 uses a first pushing cylinder 24 to push the push-down piston 23 and the upward piston 22 at the middle position of the top wall and the bottom wall, and the quantitative cylinder 2 uses two limit movable rods 25 on the top wall and the bottom wall to connect to the push-down piston 23 and the upward piston 22;

[0039] The metering cylinder 2 is provided to take a quantitative amount of the gas to be measured, so that the particles are retained later and the water vapor is removed, and the dilution multiple is determined to prevent the particles from being different from the previous ones after being diluted. The upward piston 22 is pushed down to facilitate the inhalation of the gas to be measured, or to discharge the internal impurities (not the gas at the position to be measured) before inhalation, and the downward piston 23 is to slowly push out the gas to be measured;

[0040] The water vapor removal mechanism includes a water vapor discharge box 4, a plurality of S-shaped permeation tubes 5 and a long air supply box 3, the bottom of the long air supply box 3 is connected to the air outlet pipe of the metering cylinder 2 through a connecting pipe 31, the air inlet ends of the plurality of S-shaped permeation tubes 5 are connected to the inside of the long air supply box 3 from the side wall thereof in a row, the plurality of S-shaped permeation tubes 5 are arranged side by side in the water vapor discharge box 4 and the air outlet pipes of each S-shaped permeation tube 5 extend from the bottom wall of the water vapor discharge box 4 to the outside, a particle-free gas inlet pipe 41 is provided on the bottom wall of the water vapor discharge box 4, a particle-free gas outlet pipe 42 is provided on the top wall, and gas and water vapor through holes 51 are evenly provided on the S-shaped permeation tubes 5;

[0041] The S-type permeation tube 5 is willing to make the gas flow longer in the water vapor discharge box 4. Affected by the position of the bend, the gas will interpenetrate and flow with the water vapor discharge box 4, bringing the water vapor to the water vapor discharge box 4, so as to greatly reduce the S-type permeation tube 5 to make its content (it can also be heated to increase the water vapor flow and gasification degree). The particle-free gas inlet pipe 41 discharges dry water vapor-free gas (gas component to be measured) and flows into the water vapor discharge box 4. The water vapor discharge box 4 and multiple S-type permeation tubes 5 are set together to increase the flow rate at different speeds. In this way, there will be a pressure difference, which is more conducive to gas flow. The gas and water vapor permeation holes 51 can only allow small molecules to flow. Since particulate matter is an impurity, its particle size is thousands or even tens of thousands times that of water molecules or gas molecules. It cannot pass through the gas and water vapor permeation holes 51 and remains in the pipeline;

[0042] The gas particle removal storage mechanism includes a gas filter box 6 and a clean gas storage box 7. A gas filter box 6 is provided at the top right side of the box body 1 and a clean gas storage box 7 is provided below the gas filter box 6. The air inlet of the gas filter box 6 is provided on the right side wall of the box body 1. The rear air outlet of the gas filter box 6 is connected to the top position of the left side wall of the clean gas storage box 7 through a gas exhaust pipe 61. An exhaust gas pipe 14 is provided in the middle position of the gas exhaust pipe 61. The gas exhaust pipe 61 is provided with an air pump 611 in the upper half section of the exhaust gas pipe 14 and an electromagnetic valve in the lower half section. The exhaust gas pipe 14 is connected to the gas exhaust pipe 61 at the position A solenoid valve is provided inside, and a negative pressure piston 71 that moves up and down is provided inside the clean gas storage box 7. The bottom of the clean gas storage box 7 pushes the negative pressure piston 71 to move through the second pushing cylinder 711, and the lower surface of the negative pressure piston 71 is limited by two limiting rods. The left side wall of the clean gas storage box 7 is connected with the particle-free gas inlet pipe 41 through the first circulation pipe, and a circulation fan is provided in the first circulation pipe. The particle-free gas outlet pipe on the water vapor discharge box 4 is extended to the side wall at the air inlet end position of the gas filter box 6 and connected to the inside. The left side wall of the clean gas storage box 7 is connected with the outlet pipe of the metering cylinder 2 through the connecting pipe 73, and a solenoid valve is provided in the connected position.

[0043] At the time of startup, the gas filter box 6 will have residual gas measured previously, which needs to be emptied. At this time, it is necessary to filter for a period of time and discharge it from the exhaust gas pipe 14, and then close the solenoid valve on the exhaust gas pipe 14 to discharge the gas after filtering out water vapor and impurity particles into the clean gas storage box 7 for later use;

[0044] The temporary storage mechanism for the gas to be tested includes a temporary storage box 8 and an extrusion piston 81 symmetrically arranged in the temporary storage box 8, extrusion cylinders 811 are symmetrically arranged on both side walls of the temporary storage box 8, and the two extrusion cylinders 811 correspondingly push the extrusion piston 81, and two outer side walls of the two extrusion cylinders 811 are correspondingly provided with two limit slide bars, and the gas outlet ends of the multiple S-shaped permeation tubes 5 are connected to the top wall of the temporary storage box 8 in a row, and two rows of constant pressure tubes 82 are symmetrically arranged on the top wall of the temporary storage box 8, the bottom end of the constant pressure tube 82 is communicated with the temporary storage box 8, and the top end is closed, and the constant pressure tube 82 is provided with an electromagnetic valve near the bottom end, and uniform gas vents are provided on the tube wall above the electromagnetic valve;

[0045] The temporary storage box 8 is used to store the particles in the gas in the quantitative cylinder, and then exhaust the gas at the back to adjust the particle concentration to make it the same as or very close to the particle concentration in the outside air (the error is less than 2%), but there is no water vapor, which will cause the particles to condense in the water vapor and affect the measurement accuracy; the gas vent on the constant pressure tube 82 can only release air, but cannot discharge particles;

[0046] The particle analysis detection mechanism includes a plurality of particle content analyzers 9 and a plurality of impurity-free gas analyzers. The particle content analyzers 9 have the same structure and function as the impurity-free gas analyzers. The bottom of the temporary storage box is connected to the inlet end of the particle content analyzer 9 through a plurality of detection and analysis tubes 83. The detection and analysis tubes 83 are provided with solenoid valves at the connection position with the bottom of the temporary storage box 8 and at the connection position with the particle content analyzer 9. The detection and analysis tubes 83 are provided with a branch pipe 832 at the connection position with the particle content analyzer 9 and away from the solenoid valve, and the branch pipe 832 is provided with a solenoid valve. The right side wall of the clean gas storage box 7 is connected to the impurity-free gas analyzer through a plurality of gas analysis tubes 72, and the structure, valve number and position on the gas analysis tubes are the same as those of the particle content analyzer.

[0047] A controller 10 is provided at the top of the box body 1, and a touch panel 11 is provided outside the top wall. The controller 10 is electrically connected to the touch panel 11. The controller 10 is used to control the electrical appliances in the quantitative gas extraction mechanism, the water vapor removal mechanism, the gas particle removal storage mechanism, the temporary storage mechanism for the gas to be tested, and the gas particle analysis and detection mechanism.

[0048] The particle content analyzer 9 has the same structure as the impurity-free gas analyzer, except that the particle content analyzer 9 is used to analyze the beta-ray attenuation rate of the gas with particles, while the impurity-free gas analyzer uses the gas without water vapor and particles to measure the beta-ray attenuation rate for comparison;

[0049] When the push-down piston 23 and the push-up piston 22 of the metering cylinder are at the topmost and bottommost positions in the metering cylinder, the volume of the metering cylinder 2 between the push-down piston 23 and the push-up piston 22 is V1, and when the two squeezing pistons 81 of the temporary storage box 8 are at the two side positions in the temporary storage box 8, the volume of the temporary storage box 8 between the two squeezing pistons 81 is V2, and the volume of V1 is 2-3% larger than the volume of V2.

[0050] Since the gas moves in the pipeline and there will be residue at the solenoid valve, it cannot be completely discharged. According to actual conditions, the volume of V1 is set 2-3% larger than the volume of V2 to reduce the concentration impact of residual particles, as well as the impact of reduced water vapor content (but generally the water vapor content has a very low impact on concentration and only affects the attenuation rate).

[0051] The particle content analyzer 9 includes a detection tube 91, a β-ray emitter 94, a β-ray detector 93, an intake regulating piston 92 and an exhaust fan 95. The detection tube 91 is provided with a mounting tube near both ends thereof which is communicated with the interior of the detection tube 91 and the top of the mounting tube is closed. Both mounting tubes are provided with an ejection cylinder and the ejection cylinders are respectively provided with a β-ray emitter 94 and a β-ray detector 93. The detection tube 91 is plugged with an intake regulating piston 92. The detection tube 91 is provided with a particle filter 831 at the air inlet end but one of the detection tubes is not provided with a particle filter 831. The detection tube 91 is provided with an exhaust fan 95 at the air outlet end.

[0052] When the gas is free of water vapor and diluted to the same concentration as the measured gas, measurement can begin. After the gas is discharged into the detection tube 91, it will push the air intake regulating piston 92 so that the gas in the detection tube is discharged without affecting the measurement. When the air intake regulating piston 92 reaches the tail end, the β-ray emitter 94 and the β-ray detector 93 below can be used to emit β-rays and detect attenuation. The length of the detection tube is set according to the accuracy requirements.

[0053] The filtration pore sizes of the plurality of particle filters 831 are different, and the filtration pore sizes of the plurality of particle filters 831 are respectively 10 μm, 5 μm and 2.5 μm.

[0054] 2.5μm is similar to the PM2.5 standard test, while 10μm and 5μm are used to detect the particle size analysis range of particles larger than 2.5μm;

[0055] The gas filter box 6 is filled with a multi-layer cotton net that absorbs moisture and filters particles. It absorbs moisture and filters particles, but does not affect the flow of gas;

[0056] The outer wall of the metering cylinder 2 and the outer wall of the water vapor discharge box 4 are both provided with heating plates. The gas can be heated to increase the gas flow rate (but not the gas flow rate in the pipeline or box body), and the gasification degree can be increased, that is, the molecular weight of water in the water vapor droplets is reduced, so that the water vapor flows as a single molecule as possible;

[0057] A particle detection method is provided, using the particle detection device described above for detection, and the specific detection steps are as follows:

[0058] S1: Start the particle detection device. Before starting, the push-up piston 22 in the metering cylinder 2 fits with the push-down piston 23 at the top, and the negative pressure piston 71 in the clean gas storage box 7 is at the top of the clean gas storage box 7. After starting, the solenoid valve in the air inlet pipe 21 of the metering cylinder 2 is opened, and the solenoid valve in the exhaust air pipe 14 connected to the gas exhaust pipe 61 is opened. The push-up piston 22 is slowly pulled down to the bottom by the first push cylinder 24, so that the metering cylinder 2 is filled with the gas to be tested. The air pump 611 in the gas exhaust pipe 61 starts to pump air and discharge it from the exhaust air pipe 14, so that the impurities in the gas filter box 6 are emptied. At this time, the solenoid valve in the air inlet pipe of the metering cylinder 2 is closed, and the solenoid valve in the exhaust air pipe 14 is closed. Then, the solenoid valve in the gas exhaust pipe 61 is opened, and the negative pressure piston 71 in the clean gas storage box 7 is slowly moved down, so that the clean gas storage box 7 is filled with clean gas;

[0059] S2: Open the solenoid valve in the connecting pipe 73 and discharge the clean gas in the clean gas storage box 7 into multiple S-shaped permeation tubes 5 through the air pump in the connecting pipe 73, and then discharge it into the temporary storage box 8 for ventilation to remove the residual impurities inside. After removing the impurities, close the solenoid valve in the connecting pipe 73, open the solenoid valve in the air outlet pipe of the metering cylinder 2, and slowly move the push-down piston 23 downward to transport the gas containing particles to multiple S-shaped permeation tubes 5 and then enter the temporary storage box 8. In this process, it is also necessary to start the gas in the clean gas storage box 7 to be discharged into the water vapor discharge box 4, and then enter the gas filter box 6 to take away the water vapor. Since the two rows of constant pressure tubes 82 have There is air leakage but the particles can be retained. The temporary storage box 8 can be inflated all the time. When the piston 23 is pushed down to the bottom, the gas in the metering cylinder 2 is emptied. At this time, the solenoid valve in the air outlet pipe of the metering cylinder 2 is closed and the solenoid valve in the connecting pipe 73 is opened at the same time. The clean gas in the clean gas storage box 7 is discharged into a plurality of S-shaped permeation tubes 5 through the air pump in the connecting pipe 73, and then discharged into the temporary storage box 8, so that the gas containing particles remaining in the S-shaped permeation tube 5 is completely discharged into the temporary storage box 8. At this time, the solenoid valve in the connecting pipe 73 and the solenoid valve at the output end of the S-shaped permeation tube 5 are closed again, and the solenoid valves in the two rows of constant pressure tubes 82 are closed after the air pressure in the temporary storage box 8 is stabilized.

[0060] S3: Open the electromagnetic valve at the connection position between the detection and analysis tube 83 and the temporary storage box 8 and the electromagnetic valve in the branch pipe 832, and exhaust the impurities in the detection and analysis tube 83 by squeezing the two squeezing pistons 81, then close the electromagnetic valve on the branch pipe 832, and stop the squeezing piston 81 from moving at the same time, and the electromagnetic valve in the branch pipe on the gas analysis tube 72 is also opened, and the impurities are exhausted by the air pump in the gas analysis tube 72, and then close the electromagnetic valve in the branch pipe on the gas analysis tube 72, open the electromagnetic valves in the near-end of multiple particle content analyzers 9 and multiple impurity-free gas analyzers, and open the electromagnetic valves in the gas analysis tube 72 and the detection and analysis tube 83 at the same time, fill the multiple particle content analyzers 9 and multiple impurity-free gas analyzers with gas containing particles and clean gas, respectively, and start the analysis, the impurity-free gas analyzer is used to analyze the effect of the particle-free and water vapor-free gas on the β-ray attenuation rate as a reference, and the particle content analyzer 9 is used to analyze the effect of the particulate matter gas on the β-ray attenuation rate to detect the particle content;

[0061] S4: The controller 10 analyzes the beta ray attenuation rates detected by the plurality of particle content analyzers 9 and compares the beta ray attenuation rates obtained by the impurity-free gas analyzer to analyze the particle content and the particle size distribution content.

[0062] During the startup process, it generally takes 3-5 molecules to fill the quantitative gas into the quantitative cylinder 2, and the gas filter box 6 first filters the gas for 1-2 minutes to exhaust the impurities in the gas filter box 6, and then discharges them from the impurity exhaust pipe 14, and then discharges them into the clean gas storage box 7. The negative pressure piston 71 is set to exhaust the clean gas storage box 7 before the next gas measurement to prevent the residual gas inside the clean gas storage box 7 from affecting the next measurement;

[0063] The clean gas storage box 7 is used to ventilate the interior of the entire device to expel the influence of impurities. After the gas to be measured is discharged, some of the gas cannot enter the temporary storage box. The clean gas storage box 7 is used to push it to expel the residual gas to be measured. The clean gas storage box 7 is then used to dilute and adjust the pressure of the storage box 7 so that its particle concentration is close to the actual measured gas concentration (the concentration is close to more than 98%), which basically does not affect the measurement accuracy. The clean gas in the clean gas storage box 7 is used as a control, and the attenuation rate of the measured gas to β rays is used as a reference to improve the measurement accuracy.

[0064] The method for using a plurality of the particle content analyzers 9 and a plurality of impurity-free gas analyzers to detect the effect of gas on the attenuation rate of beta rays is as follows: 1. Gas enters from the air inlet end of the particle content analyzer 9 to push the air inlet regulating piston 92 to move from the air inlet end to the air outlet end so that the gas to be tested fills the detection tube 91. At this time, the solenoid valve on the branch pipe 832 is opened for 2-3 seconds to make the gas in the detection tube 91 constant with the outside pressure, and then the solenoid valve on the branch pipe 832 is closed; 2. The beta ray emitter 94 and the beta ray detector 93 are pushed into the detection tube 91 by the push cylinder. , the two are in relative arrangement, the β-ray emitter 94 and the β-ray detector 93 are started to work, the β-ray emitter 94 emits β-rays, and the β-ray detector 93 detects the β-ray attenuation rate. After the detection, the β-ray emitter 94 and the β-ray detector 93 are put away; 3. The electromagnetic valve in the branch pipe 832 on the detection and analysis tube 83 is opened, and the exhaust fan 95 exhausts the gas into the detection tube 91 to push the intake regulating piston 91, and the measured gas is discharged from the branch pipe 831, and then the electromagnetic valve in the branch pipe 832 is closed, and the next detection is waited for, and the next detection step is the same as above;

[0065] The detection steps of the impurity-free gas analyzer are the same as those of the particle content analyzer 9.

[0066] The detection principles of the β-ray emitter 94 and the β-ray detector 93 are no longer cumbersome and are common knowledge.

[0067] The particle filter 831 disposed on the inlet pipe of each particle content analyzer 9 has a different filtration aperture, and the filtration apertures of the plurality of particle filters 831 are 10 μm, 5 μm and 2.5 μm respectively, and there is one particle content analyzer 9 on which the inlet pipe is not provided with a particle filter;

[0068] After passing through the particle filter 831 with a pore size of 10 μm, the particle size of the particles entering the detection tube 91 is less than 10 μm;

[0069] After passing through the particle filter 831 with a pore size of 5 μm, the particle size of the particles entering the detection tube 91 is less than 5 μm;

[0070] After passing through the particle filter 831 with a pore size of 2.5 μm, the particle size of the particles entering the detection tube 91 is less than 2.5 μm.

[0071] The attenuation rate is measured step by step at different particle concentrations as needed. One is to calculate the attenuation rate affected by all particles without filtering. Then, larger particles are gradually filtered and multi-level attenuation rate measurements are performed. Finally, the content of particles smaller than 2.5μm (i.e. PM2.5) is measured.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A particle detection device, characterized in that: It comprises a box body (1) and a quantitative gas extraction mechanism, a water vapor removal mechanism, a gas particle removal storage mechanism, a temporary storage mechanism for gas to be tested and a gas particle analysis and detection mechanism arranged in the box body (1); The quantitative gas extraction mechanism is arranged on the left side of the box body (1), and comprises a quantitative cylinder (2), a push-down piston (23), an upward piston (22) and a first pushing cylinder (24). When the downward piston (23) in the quantitative cylinder (2) is at the top end in the cylinder, an air intake pipe (21) for measuring gas is provided on the side wall of the quantitative cylinder (2) near the lower surface of the push-down piston (23), and an electromagnetic valve is provided in the air intake pipe (21). When the plug (22) is at the bottom end in the cylinder, an air outlet pipe is provided on the other side wall of the metering cylinder (2) near the upper surface of the push-up piston (22), and an electromagnetic valve is provided in the air outlet pipe. The metering cylinder (2) uses a first push cylinder (24) at the middle position of the top wall and the bottom wall to push the push-down piston (23) and the push-up piston (22). The metering cylinder (2) uses two limit movable rods (25) on the top wall and the bottom wall to connect to the push-down piston (23) and the push-up piston (22); The water vapor removal mechanism comprises a water vapor discharge box (4), a plurality of S-shaped permeation tubes (5) and a long air supply box (3); the bottom of the long air supply box (3) is connected to the air outlet pipe of the metering cylinder (2) through a connecting pipe (31); the air inlet ends of the plurality of S-shaped permeation tubes (5) are arranged in a row and communicate with the interior of the long air supply box (3) from the side wall thereof; the plurality of S-shaped permeation tubes (5) are arranged side by side in the water vapor discharge box (4) and the air outlet pipe of each S-shaped permeation tube (5) extends from the bottom wall of the water vapor discharge box (4) to the outside; a particle-free gas inlet pipe (41) is provided on the bottom wall of the water vapor discharge box (4) and a particle-free gas outlet pipe (42) is provided on the top wall; and gas and water vapor through holes (51) are evenly provided on the S-shaped permeation tubes (5); The gas particle removal storage mechanism comprises a gas filter box (6) and a clean gas storage box (7); a gas filter box (6) is provided at the top right side of the box body (1) and a clean gas storage box (7) is provided below the gas filter box (6); an air inlet of the gas filter box (6) is provided on the right side wall of the box body (1); a rear air outlet of the gas filter box (6) is connected to the top left side wall of the clean gas storage box (7) through a gas exhaust pipe (61); a gas exhaust pipe (14) is provided in the middle of the gas exhaust pipe (61); an air pump (611) is provided in the upper half section of the gas exhaust pipe (14) and an electromagnetic valve is provided in the lower half section; the gas exhaust pipe (14) is connected to the gas exhaust pipe (61) and a gas exhaust pump (611) is provided in the lower half section; A solenoid valve is provided in the position of the clean gas storage box (7); a negative pressure piston (71) movable up and down is provided in the clean gas storage box (7); the bottom of the clean gas storage box (7) is pushed to move the negative pressure piston (71) by a second pushing cylinder (711), and the lower surface of the negative pressure piston (71) is limited by two limiting rods; the left side wall of the clean gas storage box (7) is connected to the particle-free gas inlet pipe (41) through a first circulation pipe, and a circulation fan is provided in the first circulation pipe; the particle-free gas outlet pipe (42) on the water vapor discharge box (4) is extended to the side wall of the gas filter box (6) at the inlet end position and is connected to the inside; the left side wall of the clean gas storage box (7) is connected to the outlet pipe of the metering cylinder (2) through a connecting pipe (73), and a solenoid valve is provided in the connected position; The temporary storage mechanism for the gas to be tested comprises a temporary storage box (8) and an extrusion piston (81) symmetrically arranged in the temporary storage box (8), extrusion cylinders (811) symmetrically arranged on both side walls of the temporary storage box (8) and the two extrusion cylinders (811) correspondingly push the extrusion pistons (81), and two limit slide bars are correspondingly arranged on the outer side walls of the two extrusion cylinders (811), and the gas outlet ends of the plurality of S-shaped permeation tubes (5) are connected to the top wall of the temporary storage box (8) in a row, and two rows of constant pressure tubes (82) are symmetrically arranged on the top wall of the temporary storage box (8), the bottom end of the constant pressure tube (82) is communicated with the inside of the temporary storage box (8) and the top end is closed, and the constant pressure tube (82) is provided with an electromagnetic valve near the bottom end, and uniform gas vents are arranged on the tube wall above the electromagnetic valve; The particle analysis detection mechanism comprises a plurality of particle content analyzers (9) and a plurality of impurity-free gas analyzers. The particle content analyzers (9) have the same structure and function as the impurity-free gas analyzers. The bottom of the temporary storage box is connected to the inlet of the particle content analyzer (9) through a plurality of detection and analysis tubes (83). The detection and analysis tubes (83) are provided with solenoid valves at the connection position with the bottom of the temporary storage box (8) and at the connection position with the particle content analyzer (9). The detection and analysis tubes (83) are provided with a branch pipe (832) at the connection position with the particle content analyzer (9) and a distance away from the solenoid valve, and the branch pipe (832) is provided with a solenoid valve. The right side wall of the clean gas storage box (7) is connected to the impurity-free gas analyzer through a plurality of gas analysis tubes (72), and the structure, number and position of valves on the gas analysis tubes are the same as those of the particle content analyzer. A controller (10) is provided on the top of the box body (1), and a touch panel (11) is provided on the outside of the top wall. The controller (10) is electrically connected to the touch panel (11). The controller (10) is used to control the operation of electrical appliances in a quantitative gas extraction mechanism, a water vapor removal mechanism, a gas particle removal storage mechanism, a temporary storage mechanism for gas to be tested, and a gas particle analysis and detection mechanism.

2. A particle detection device according to claim 1, characterized in that: When the push-down piston (23) and the push-up piston (22) of the metering cylinder are at the topmost and bottommost positions in the metering cylinder, the volume of the metering cylinder (2) between the push-down piston (23) and the push-up piston (22) is V1; when the two squeezing pistons (81) of the temporary storage box (8) are at the two sidemost positions in the temporary storage box (8), the volume of the temporary storage box (8) between the two squeezing pistons (81) is V2; the volume of V1 is 2-3% larger than the volume of V2.

3. A particle detection device according to claim 1, characterized in that: The particle content analyzer (9) comprises a detection tube (91), a β-ray emitter (94), a β-ray detector (93), an air intake regulating piston (92) and an exhaust fan (95). The detection tube (91) is provided with a mounting tube near both ends thereof, which is communicated with the interior of the detection tube (91) and the top of the mounting tube is closed. Both mounting tubes are provided with a push-out cylinder, and the push-out cylinders are provided with a β-ray emitter (94) and a β-ray detector (93) respectively. The detection tube (91) is plugged with an air intake regulating piston (92). The air intake end of the detection tube (91) is provided with a particle filter (831) but one of the detection tubes is not provided with a particle filter (831). The air outlet end of the detection tube (91) is provided with an exhaust fan (95).

4. A particle detection device according to claim 3, characterized in that: The filtration pore sizes of the plurality of particle filters (831) are different, and the filtration pore sizes of the plurality of particle filters (831) are respectively 10 μm, 5 μm and 2.5 μm.

5. A particle detection device according to claim 1, characterized in that: The gas filter box (6) is filled with a multi-layer cotton net for absorbing water vapor and filtering particles.

6. A particle detection device according to claim 1, characterized in that: The outer wall of the metering cylinder (2) and the outer wall of the water vapor discharge box (4) are both provided with heating plates.

7. A particle detection method, characterized in that: The particle detection device described in claims 1 to 6 is used for detection, and the specific detection steps are as follows: S1: Start the particle detection device. Before starting, the upward push piston (22) in the metering cylinder (2) is in contact with the downward push piston (23) at the top, and the negative pressure piston (71) in the clean gas storage box (7) is at the top of the clean gas storage box (7). After starting, the electromagnetic valve in the air inlet pipe (21) of the metering cylinder (2) is opened, and the electromagnetic valve in the impurity exhaust pipe (14) connected to the gas exhaust pipe (61) is opened, and the upward push piston (22) is slowly pulled down to the bottom by the first push cylinder (24). end, so that the measuring cylinder (2) is filled with the gas to be measured, and the vacuum pump (611) in the gas exhaust pipe (61) starts to exhaust gas and discharges it from the impurity exhaust pipe (14), so that the impurity gas in the gas filter box (6) is emptied. At this time, the electromagnetic valve in the air inlet pipe of the measuring cylinder (2) is closed, and the electromagnetic valve in the impurity exhaust pipe (14) is closed. Then, the electromagnetic valve in the gas exhaust pipe (61) is opened, and the negative pressure piston (71) in the clean gas storage box (7) is slowly moved downward, so that the clean gas storage box (7) is filled with clean gas; S2: Open the electromagnetic valve in the connecting pipe (73) and discharge the clean gas in the clean gas storage box (7) into a plurality of S-shaped permeation tubes (5) through the air pump in the connecting pipe (73), and then discharge it into the temporary storage box (8) for ventilation to remove the residual impurities in the interior. After removing the impurities, close the electromagnetic valve in the connecting pipe (73), open the electromagnetic valve in the air outlet pipe of the metering cylinder (2), and slowly move the push-down piston (23) downward to transport the gas containing particles into the plurality of S-shaped permeation tubes (5) and then into the temporary storage box (8). In this process, it is also necessary to start the gas in the clean gas storage box (7) to be discharged into the water vapor discharge box (4), and then enter the gas filter box (6) to carry away the water vapor. Since the two rows of constant pressure tubes (82) have The effect of deflation but retaining particles can be achieved by continuously inflating the temporary storage box (8). When the piston (23) is pushed down to the bottom, the gas in the metering cylinder (2) is emptied. At this time, the electromagnetic valve in the air outlet pipe of the metering cylinder (2) is closed and the electromagnetic valve in the connecting pipe (73) is opened at the same time. The clean gas in the clean gas storage box (7) is discharged into a plurality of S-shaped permeation tubes (5) through the air pump in the connecting pipe (73), and then discharged into the temporary storage box (8), so that the gas containing particles remaining in the S-shaped permeation tube (5) is completely discharged into the temporary storage box (8). At this time, the electromagnetic valve in the connecting pipe (73) and the electromagnetic valve at the output end of the S-shaped permeation tube (5) are closed again, and after the air pressure in the temporary storage box (8) is stabilized, the electromagnetic valves in the two rows of constant pressure tubes (82) are closed. S3: Open the electromagnetic valve at the connection position between the detection and analysis tube (83) and the temporary storage box (8) and the electromagnetic valve in the branch pipe (832), and exhaust the impurities in the detection and analysis tube (83) by squeezing the two squeezing pistons (81), then close the electromagnetic valve on the branch pipe (832), and stop the movement of the squeezing piston (81) at the same time. The electromagnetic valve in the branch pipe on the gas analysis tube (72) is also opened, and the impurities are exhausted by the air pump in the gas analysis tube (72), and then close the electromagnetic valve in the branch pipe on the gas analysis tube (72), and open multiple particle content analysis The electromagnetic valves in the near-end of the analyzer (9) and the multiple impurity-free gas analyzers are opened, and the electromagnetic valves in the gas analysis tube (72) and the detection analysis tube (83) are opened at the same time, and the gas containing particles and the clean gas are respectively filled into the multiple particle content analyzers (9) and the multiple impurity-free gas analyzers, and the analysis is started. The impurity-free gas analyzer is used to analyze the effect of the gas without particles and water vapor on the attenuation rate of beta rays as a reference, and the particle content analyzer (9) is used to analyze the effect of the gas containing particles on the attenuation rate of beta rays to detect the particle content; S4: The controller (10) analyzes the beta ray attenuation rates detected by the plurality of particle content analyzers (9) and compares the beta ray attenuation rates obtained by the impurity-free gas analyzer to analyze the particle content and the particle size distribution content.

8. A particle detection method according to claim 7, characterized in that: The method for using a plurality of the particle content analyzers (9) and a plurality of impurity-free gas analyzers to detect the effect of gas on the attenuation rate of beta rays is as follows:

1. Gas enters from the air inlet end of the particle content analyzer (9) to push the air inlet regulating piston (92) to move from the air inlet end to the air outlet end so that the gas to be tested fills the detection tube (91). At this time, the solenoid valve on the branch pipe (832) is opened for 2-3 seconds to make the gas in the detection tube (91) and the outside pressure constant, and then the solenoid valve on the branch pipe (832) is closed; 2. The beta ray emitter (94) and the beta ray detector (93) are pushed into the detection tube (91) by the push cylinder, and the two are pushed into the detection tube (91). In a relative setting, the β-ray emitter (94) and the β-ray detector (93) are started to work, the β-ray emitter (94) emits β-rays, and the β-ray detector (93) detects the β-ray attenuation rate. After the detection, the β-ray emitter (94) and the β-ray detector (93) are folded; 3. The solenoid valve in the branch pipe (832) on the detection and analysis tube (83) is opened, and the exhaust fan (95) exhausts the gas into the detection tube (91) to push the intake regulating piston (91), and the measured gas is discharged from the branch pipe (831), and then the solenoid valve in the branch pipe (832) is closed, and the next detection is waited, and the next detection step is the same as above; The detection steps of the impurity-free gas analyzer are the same as those of the particle content analyzer (9).

9. A particle detection method according to claim 8, characterized in that: The particle filters (831) provided on the inlet pipe of each particle content analyzer (9) have different filtration apertures, and the filtration apertures of the plurality of particle filters (831) are respectively 10 μm, 5 μm and 2.5 μm, and there is one particle content analyzer whose inlet pipe is not provided with a particle filter; After passing through the particle filter (831) with a pore size of 10 μm, the particles entering the detection tube (91) have a particle size of less than 10 μm; After passing through the particle filter (831) with a pore size of 5 μm, the particle size of the particles entering the detection tube (91) is less than 5 μm; After passing through the particle filter (831) with a pore size of 2.5 μm, the particles entering the detection tube (91) have a particle size of less than 2.5 μm.

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