Multi-channel particulate matter wet sampling technology

Abstract

The invention discloses a multi-channel particulate matter wet sampling technology which comprises an absorption unit, a sampling unit, a power unit, a control system and control software. The absorption unit, the sampling unit and the power unit in the multi-channel particulate matter wet sampling system corresponding to the sampling technology are sequentially connected in series, the control software is installed on the control system, the sampling unit comprises a gas inlet, a sampling head and an electromagnetic valve, and the absorption unit comprises two or more gas absorption bottles. A single-stage or multi-stage absorption device filled with strong acid and a surfactant solution is used for replacing a traditional filter membrane or is additionally arranged between the traditional filter membrane and a power unit of the sampler, so that air particulate matters with all particle sizes in air can be effectively absorbed, and the interception efficiency of the sampling system on the air particulate matters is greatly improved. In the implementation process, an appropriate solution can be selected in advance to absorb the air particulate matters according to the sampling purpose, and the particle size and composition information of the air particulate matters can be obtained under the condition that the composition of the air particulate matters is not damaged.

Description

Technical Field

[0001] The invention relates to the technical field of particle sampling, in particular to a multi-channel particle wet sampling technology. Background Art

[0002] Air environment monitoring and assessment around facilities such as nuclear power plants, chemical plants, and waste treatment plants is the basis for the safe operation of the above facilities. With the improvement of national policies and regulations and the demand for a safe living environment for the people, it is necessary to conduct a detailed analysis of all components and concentrations of particulate matter in the air under the above scenarios to provide effective data support for environmental quality assessment. Traditional air particulate samplers (such as PM10, PM2.5 samplers, air particulate high-flow samplers, air particulate total dust samplers, etc.) mostly sample through the filter membrane method, that is, a mechanical pump is used to collect air particles on the filter membrane through adsorption. However, since the filter membrane itself has a porous structure, the interception efficiency of air particles is low, and air particles with smaller particle sizes cannot be adsorbed on the filter membrane. Therefore, the traditional air particle sampling method can only collect particles above a specific particle size, and cannot achieve the collection of particles of all particle sizes in the air.

[0003] Air particles smaller than the filter membrane pore size (0.45 μm) are usually adsorbed with various particles (radioactive aerosol particles, SO x Dust (such as NOx, etc.) can be quickly dissolved in oxidizing strong acid solutions such as nitric acid or captured by corresponding surfactant solutions. Based on this, a multi-channel particulate matter wet sampling technology is proposed to optimize the existing sampling technology. Summary of the invention

[0004] The object of the present invention is to provide a multi-channel particulate wet sampling technology, which designs a multi-channel particulate wet sampling system to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A multi-channel particulate wet sampling system comprises an absorption unit, a sampling unit, a power unit, a control system and control software, wherein the absorption unit, the sampling unit and the power unit are connected in series in sequence, and the control software is installed on the control system, the sampling unit comprises an air inlet, a sampling head and a solenoid valve, the air inlet adopts a sleeve form to connect a polytetrafluoroethylene lined corrugated tube and a stainless steel sleeve tube, the stainless steel sleeve tube is a straight-connected tube, a three-way tube or a multi-way tube, each port of the stainless steel sleeve tube is connected to a solenoid valve, the air outlet end of the solenoid valve is connected to a first air guide tube, the first air guide tube is connected to the sampling head, and the tail end of each sampling head is connected to A second air duct, each of which is connected to an absorption unit, the absorption unit includes two or more gas absorption bottles, the absorption bottles are provided with absorption solution, the air inlet end of the first absorption bottle is connected to the second air duct, the absorption unit also includes a buffer bottle, the absorption bottle and the buffer bottle are both made of polyperfluoroethylene propylene and the bottle body has a scale, the gas outlet port of the buffer bottle is commonly connected to a third air duct, the third air duct has the same number of interfaces as the stainless steel sleeve, the absorption bottle and the buffer bottle are sequentially connected in series to form a whole, the third air duct is connected to a power unit, and the power unit includes a vacuum pump, a mass flow controller, and a dryer.

[0006] As a further solution of the present invention: the sampling head includes an outer shell, porous nickel, a filter membrane and a filter membrane holder, the filter membrane is a glass fiber filter membrane, the outer shell is made of stainless steel or aluminum alloy, the filter membrane holder is made of stainless steel, the filter membrane is clamped between the porous nickel and the filter membrane holder that are compatible with it, the porous nickel is arranged at the front end of the filter membrane, the filter membrane holder is arranged at the rear end of the filter membrane, and the porous nickel, the filter membrane and the filter membrane holder are clamped and fixed together in the outer shell.

[0007] As a further solution of the present invention: the absorption bottle and the buffer bottle are both fixedly mounted on the bracket, the bracket is fixedly mounted on the shock-absorbing support, and the vacuum pump is fixedly mounted on the shock-absorbing support and is located on the bottom inner side of the bracket.

[0008] As a further solution of the present invention: the top openings of the absorption bottle and the buffer bottle are both threadedly connected with sealing screw caps, a long tube and a short tube are inserted in the absorption bottle, and two short tubes are inserted in the buffer bottle. The long tube and the short tube are both connected to the sealing screw cap. The long tube extends to the bottom of the absorption bottle and is fixedly connected with an airflow dispersion head, which is made of polytetrafluoroethylene, and the short tubes are inserted into the inner side of the top of the corresponding absorption bottle and buffer bottle.

[0009] As a further solution of the present invention: the top ends of the long tube and the short tube are fixedly connected with quick-plug connectors, a fourth air duct is provided between the short tube on the front absorption bottle and the long tube on the rear absorption bottle, a fourth air duct is also provided between the short tube on the absorption bottle at the tail end and a short tube on the buffer bottle, both ends of the fourth air duct are respectively connected to the corresponding long tube and short tube through quick-plug connectors, the long tube on the front absorption bottle is connected to the second air duct through the quick-plug connector, and the other short tube on the buffer bottle is connected to a port of the third air duct through the quick-plug connector.

[0010] As a further solution of the present invention: the front end of the mass flow controller is connected to a fifth air duct, the rear end of the mass flow controller is connected to a sixth air duct, one end of the sixth air duct is connected to the air inlet end of the vacuum pump, and a dryer is installed between the ends of the fifth air duct and the sixth air duct. The dryer includes a filling tube and a threaded cap, the threaded cap is threadedly connected to both ends of the filling tube, and the filling tube is filled with a desiccant, which is anhydrous calcium chloride particles. The threaded cap is fixedly connected with a sieve plate, and the sieve plate prevents the desiccant from entering the fifth air duct and the sixth air duct without affecting the flow rate. The two threaded caps are respectively connected to the fifth air duct and the sixth air duct.

[0011] As a further solution of the present invention: the control system includes a communication line, a switch, a controller and a control computer. The communication line is used to connect the controller and the switch, and the switch and the control computer. The switch is connected to multiple controllers at the same time to achieve signal interaction. The controller is installed on a bracket. The controller is made of metal, has a built-in power supply, Ethernet, no less than eight ports, fan heat dissipation, a downstream rate of 1 Gigabit, and an upstream rate of 10 Gigabit; the control computer must meet the basic requirements for the operation of the control software.

[0012] As a further solution of the present invention: the control software is used for operators to remotely control and monitor the working status of the device. The control software can simultaneously control the sequential sampling of multiple channels of the device, and can control the sampling time, sampling flow, opening and closing of the solenoid valve, etc.; parameters such as instantaneous flow, sampling time, and cumulative volume need to be displayed in real time and stored on the control computer end. When switching the sampling channel, the instantaneous flow and cumulative volume need to be re-recorded, and the sampling data of the previous channel continues to be retained; the control software needs to have high compatibility and good stability.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention studies and establishes a wet sampling technology for air particles. The technology designs a multi-channel wet sampling system for particles, which contains a wet absorption unit and a dry sampling unit. The two can be used in conjunction in a sampling channel or independently as a single sampling channel. The wet absorption unit is cleverly combined with the traditional air particle sampling device / system to form a new sampling device / system, which has the advantages of good reliability, strong operability, and high accuracy in air particle sampling. It can realize remote control of multi-channel and multi-sequence sampling of full-size air particle concentration, effectively solving the problem that traditional sampling devices / systems cannot obtain full-size air particles, and providing reliable technical support for air particle concentration monitoring in complex environments. This technology is not only suitable for remote control sampling of full-size air particles in scenes such as chemical plants and fires, but can also be used for full-size air particle sampling in strong dynamic load environments such as explosion mechanics tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of a multi-channel particulate matter wet sampling technology.

[0015] Figure 2 This is a front view of a two-channel three-stage wet sampling technology in a multi-channel particulate matter wet sampling technology.

[0016] Figure 3 This is a side view showing two-channel three-stage wet sampling in a multi-channel particulate matter wet sampling technology.

[0017] Figure 4 This is a front view of a two-channel, two-stage dry-wet series sampling in a multi-channel particulate matter wet sampling technology.

[0018] Figure 5 This is a side view showing two-channel two-stage dry-wet series sampling in a multi-channel particulate matter wet sampling technology.

[0019] Figure 6 A diagram showing the sampling head used in a multi-channel wet particulate matter sampling technique.

[0020] Figure 7 A diagram showing a dryer used in a multi-channel wet particulate matter sampling technique.

[0021] In the figure: 1. sampling head; 2. solenoid valve; 3. mass flow controller; 4. vacuum pump; 5. buffer bottle; 6. dryer; 7. controller; 8. sieve plate; 9. absorption bottle; 10. air inlet; 11. polytetrafluoroethylene lined bellows; 12. stainless steel sleeve; 13. first air duct; 14. second air duct; 15. third air duct; 16. outer shell; 17. porous nickel; 18. filter membrane; 19. filter membrane bracket; 20. bracket; 21. shock-absorbing support; 22. sealing screw cap; 23. long tube; 24. short tube; 25. air flow dispersion head; 26. quick-connect interface; 27. fourth air duct; 28. fifth air duct; 29. ​​sixth air duct; 30. filling tube; 31. threaded screw cap. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figures 1 to 7In an embodiment of the present invention, a multi-channel particulate wet sampling system includes an absorption unit, a sampling unit, a power unit, a control system and control software. The absorption unit, the sampling unit and the power unit are connected in series in sequence. The control software is installed on the control system. The sampling unit includes an air inlet 10, a sampling head 1 and a solenoid valve 2. The response time of the solenoid valve 2 is less than 0.3s. The medium is air. The diameter of the gas channel is greater than 4mm. The air inlet 10 is connected to the polytetrafluoroethylene lined bellows 11 and the stainless steel sleeve 12 in the form of a sleeve. The polytetrafluoroethylene lined bellows 11 is connected to the air extraction chamber. The stainless steel sleeve 12 is a straight pipe, a three-way pipe or a multi-way pipe. Each port of the stainless steel sleeve 12 is connected to a solenoid valve 2. The air outlet end of the solenoid valve 2 is connected to a first air guide pipe 13. The first air guide pipe 13 is connected to the sampling head 1. The tail end of each sampling head 1 is connected to a second air guide pipe 14. Each second air guide pipe 14 is connected to an absorption The absorption unit is connected, the absorption unit includes two or more gas absorption bottles 9, the absorption bottle 9 is provided with an absorption solution, the absorption solution can be a strong oxidizing acid such as nitric acid, a surfactant, a clustering agent, etc., the air inlet end of the first absorption bottle 9 is connected to the second air duct 14, the absorption unit also includes a buffer bottle 5, the absorption bottle 9 and the buffer bottle 5 are both made of polyperfluoroethylene propylene and the bottle body has a scale, the volume is not less than 300mL, the gas outlet port of the buffer bottle 5 is commonly connected to a third air duct 15, the third air duct 15 and the stainless steel sleeve 12 have the same number of interfaces, the absorption bottle 9 and the buffer bottle 5 are connected in series in sequence to form a whole, the third air duct 15 is connected to the power unit, the power unit includes a vacuum pump 4, a mass flow controller 3, and a dryer 6, the vacuum pump 4 has a flow rate of not less than 100L / min, and a power of less than 1.5kW; the mass flow controller 3 has a flow control upper limit of 120L / min, and a flow control error of less than 1.5%.

[0024] The sampling head 1 includes a shell 16, a porous nickel 17, a filter membrane 18 and a filter membrane holder 19. The pore size of the porous nickel 17 is 1 mm. The filter membrane 18 is a glass fiber filter membrane with a diameter of 40 to 50 mm and a pore size of 0.45 μm. The shell 16 is made of stainless steel or aluminum alloy. The filter membrane holder 19 is made of stainless steel and has a pore size of 1 mm. The filter membrane 18 is clamped between the porous nickel 17 and the filter membrane holder 19 that are compatible with it. The porous nickel 17 is arranged at the front end of the filter membrane 18, and the filter membrane holder 19 is arranged at the rear end of the filter membrane 18. The porous nickel 17, the filter membrane 18 and the filter membrane holder 19 are clamped and fixed together in the shell 16.

[0025] The absorption bottle 9 and the buffer bottle 5 are both fixedly mounted on the bracket 20 , the bracket 20 is fixedly mounted on the shock-absorbing support 21 , and the vacuum pump 4 is fixedly mounted on the shock-absorbing support 21 and is located at the bottom inner side of the bracket 20 .

[0026] The top openings of the absorption bottle 9 and the buffer bottle 5 are both threadedly connected with a sealing screw cap 22. A long tube 23 and a short tube 24 are inserted into the absorption bottle 9, and two short tubes 24 are inserted into the buffer bottle 5. The long tube 23 and the short tube 24 are both connected to the sealing screw cap 22. The long tube 23 extends to the bottom of the absorption bottle 9 and is fixedly connected to an airflow dispersion head 25. The airflow dispersion head 25 is made of polytetrafluoroethylene, with a length of 3.5±0.1cm. Gas dispersion micropores are opened along its surface. The micropore diameter is 1±0.1mm, and the distance between the upper and lower holes is 3±0.1mm; the short tubes 24 are inserted into the inner side of the top of the corresponding absorption bottle 9 and the buffer bottle 5.

[0027] The top ends of the long tube 23 and the short tube 24 are fixedly connected with a quick-plug interface 26. A fourth air duct 27 is provided between the short tube 24 on the front absorption bottle 9 and the long tube 23 on the rear absorption bottle 9. A fourth air duct 27 is also provided between the short tube 24 on the absorption bottle 9 at the tail end and a short tube 24 on the buffer bottle 5. Both ends of the fourth air duct 27 are respectively connected to the corresponding long tube 23 and short tube 24 through the quick-plug interface 26. The long tube 23 on the front absorption bottle 9 is connected to the second air duct 14 through the quick-plug interface 26. The other short tube 24 on the buffer bottle 5 is connected to a port of the third air duct 15 through the quick-plug interface 26.

[0028] The front end of the mass flow controller 3 is connected to the fifth air duct 28, and the rear end of the mass flow controller 3 is connected to the sixth air duct 29. One end of the sixth air duct 29 is connected to the air inlet end of the vacuum pump 4. The dryer 6 is installed between the ends of the fifth air duct 28 and the sixth air duct 29. The dryer 6 includes a filling tube 30 and a threaded screw cap 31. The threaded screw cap 31 is threadedly connected to both ends of the filling tube 30. The filling tube 30 is filled with a desiccant, and the desiccant is anhydrous calcium chloride particles. The threaded screw cap 31 is fixedly connected with a sieve plate 8. The sieve plate 8 prevents the desiccant from entering the fifth air duct 28 and the sixth air duct 29 without affecting the flow rate. The two threaded screw caps 31 are respectively connected to the fifth air duct 28 and the sixth air duct 29.

[0029] The control system includes a communication line, a switch, a controller 7 and a control computer. The communication line is used to connect the controller 7 with the switch, and the switch with the control computer. The communication line can be a Category 6 network cable or an optical fiber. The switch is connected to multiple controllers 7 at the same time to achieve signal interaction. The controller 7 is installed on a bracket 20. The controller 7 is made of metal, has a built-in power supply, Ethernet, no less than eight ports, fan heat dissipation, a downstream rate of 1 Gigabit, and an upstream rate of 10 Gigabit; the control computer must meet the basic requirements for the operation of the control software.

[0030] The control software is used by operators to remotely control and monitor the working status of the device. The control software can simultaneously control the sequential sampling of multiple channels of the device, and can control the sampling time, sampling flow, solenoid valve opening and closing, etc.; instantaneous flow, sampling time, cumulative volume and other parameters need to be displayed in real time and stored on the control computer. When switching the sampling channel, the instantaneous flow and cumulative volume must be re-recorded, and the sampling data of the previous channel will continue to be retained; the control software needs to have high compatibility and good stability.

[0031] By designing a liquid sampling unit and using a single-stage or multi-stage absorption device filled with strong acid or surfactant solution to replace the traditional filter membrane, or installing it between the traditional filter membrane and the sampler power unit (mechanical pump), air particles of all particle sizes in the air can be effectively absorbed, greatly improving the interception efficiency of the sampling device / system for air particles.

[0032] During the implementation process, according to the sampling purpose, a suitable solution can be pre-selected to absorb air particles, so as to obtain the particle size and composition information of the air particles without destroying the composition of the air particles, thereby solving the problem that traditional samplers cannot obtain the full particle size distribution information of air particles.

[0033] The first air guide tube 13 , the second air guide tube 14 , the third air guide tube 15 , the long tube 23 , the short tube 24 , the fourth air guide tube 27 , the fifth air guide tube 28 and the sixth air guide tube 29 are all made of polytetrafluoroethylene.

[0034] The working principle of the present invention is: When in use, a multi-channel particulate wet sampling device / system is arranged: the multi-channel particulate wet sampling device / system is composed of an absorption unit, a sampling unit, a power unit, a control system and a control software, wherein the absorption unit, the sampling unit and the power unit can be integrated and solidified in a bracket 20. Specifically, the absorption solution is selected in advance according to the type of air particulate matter and the required information; the sampling device / system is arranged and the absorption solution is filled at the sampling site; the sampling device / system is connected to the control system through a signal line, and the control system transmits the device / system control signal to the control software.

[0035] The absorption unit is composed of a buffer bottle 5 and an absorption bottle 9; the sampling unit is composed of a sampling head 1 and a solenoid valve 2; the power unit is composed of a mass flow controller 3, a vacuum pump 4, a dryer 6, etc.; the three are integrated in a bracket 20, which is made of stainless steel, has a sampling port, and is generally more than 3 mm thick.

[0036] Debug the communication between the remote control computer and the wet sampling device / system. Use the remote control computer to control one or more wet sampling devices / systems and check whether the control and communication are normal.

[0037] Set sampling parameters. Set the sampling flow, sampling time, sampling sequence and other parameters of the multi-channel particulate wet sampling system.

[0038] Take air particle samples. Use a remote control computer to remotely control the multi-channel wet particulate sampling system according to the established parameters to take air particle samples.

[0039] Retrieve and inspect the multi-channel wet sampling system for particulate matter. After sampling is completed, retrieve all multi-channel wet sampling systems for particulate matter and inspect the equipment for damage. Turn off all power to the system, remove the connecting wires between the components, and pack the components of the system back.

[0040] Absorption solution sample recovery. Take out the collected solution sample from the multi-channel particulate wet sampling system and immediately pre-treat and analyze it. If the sample cannot be processed immediately, the sample needs to be sealed with a polytetrafluoroethylene bottle and stored in a refrigerator for analysis.

[0041] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-channel particulate matter wet sampling system, comprising an absorption unit, a sampling unit, a power unit, a control system and control software, characterized in that: The absorption unit, the sampling unit and the power unit are connected in series in sequence, and the control software is installed on the control system. The sampling unit comprises an air inlet (10), a sampling head (1) and a solenoid valve (2). The air inlet (10) is connected to a polytetrafluoroethylene lined corrugated tube (11) and a stainless steel sleeve tube (12) in the form of a sleeve. The stainless steel sleeve tube (12) is a straight-connected tube, a three-way tube or a multi-way tube. Each port of the stainless steel sleeve tube (12) is connected to a solenoid valve (2). The air outlet end of the solenoid valve (2) is connected to a first air guide tube (13). The first air guide tube (13) is connected to the sampling head (1). The tail end of each sampling head (1) is connected to a second air guide tube. The invention relates to a gas absorption unit (14), wherein each second gas guide tube (14) is connected to an absorption unit, and the absorption unit comprises two or more gas absorption bottles (9), wherein the gas inlet end of the first absorption bottle (9) is connected to the second gas guide tube (14), and the absorption unit further comprises a buffer bottle (5), wherein the gas outlet port of the buffer bottle (5) is commonly connected to a third gas guide tube (15), and the third gas guide tube (15) has the same number of interfaces as the stainless steel sleeve tube (12), and the absorption bottle (9) and the buffer bottle (5) are sequentially connected in series to form a whole, and the third gas guide tube (15) is connected to a power unit, and the power unit comprises a vacuum pump (4), a mass flow controller (3) and a dryer (6).

2. The multi-channel particulate matter wet sampling system according to claim 1, characterized in that: The sampling head (1) comprises a housing (16), a porous nickel (17), a filter membrane (18) and a filter membrane support (19); the filter membrane (18) is clamped between the porous nickel (17) and the filter membrane support (19) which are compatible with the filter membrane (18); the porous nickel (17) is arranged at the front end of the filter membrane (18), and the filter membrane support (19) is arranged at the rear end of the filter membrane (18); the porous nickel (17), the filter membrane (18) and the filter membrane support (19) are clamped and fixed together in the housing (16).

3. The multi-channel particulate matter wet sampling system according to claim 1, characterized in that: The absorption bottle (9) and the buffer bottle (5) are both fixedly mounted on the bracket (20), the bracket (20) is fixedly mounted on the shock-absorbing support (21), and the vacuum pump (4) is fixedly mounted on the shock-absorbing support (21) and is located on the inner side of the bottom of the bracket (20).

4. The multi-channel particulate matter wet sampling system according to claim 1, characterized in that: The top openings of the absorption bottle (9) and the buffer bottle (5) are both threadedly connected with a sealing screw cap (22); a long tube (23) and a short tube (24) are inserted into the absorption bottle (9); two short tubes (24) are inserted into the buffer bottle (5); the long tube (23) and the short tube (24) are both connected to the sealing screw cap (22); the long tube (23) extends to the bottom of the absorption bottle (9) and is fixedly connected with an air flow dispersion head (25); and the short tube (24) is inserted into the inner side of the top of the corresponding absorption bottle (9) and buffer bottle (5).

5. The multi-channel particulate matter wet sampling system according to claim 4, characterized in that: The top ends of the long tube (23) and the short tube (24) are fixedly connected with a quick-insert interface (26); a fourth air guide tube (27) is provided between the short tube (24) on the front absorption bottle (9) and the long tube (23) on the rear absorption bottle (9); a fourth air guide tube (27) is also provided between the short tube (24) on the rear absorption bottle (9) and a short tube (24) on the buffer bottle (5); both ends of the fourth air guide tube (27) are respectively connected to the corresponding long tube (23) and short tube (24) through the quick-insert interface (26); the long tube (23) on the front absorption bottle (9) is connected to the second air guide tube (14) through the quick-insert interface (26); and the other short tube (24) on the buffer bottle (5) is connected to a port of the third air guide tube (15) through the quick-insert interface (26).

6. The multi-channel particulate matter wet sampling system according to claim 1, characterized in that: The front end of the mass flow controller (3) is connected to a fifth air guide pipe (28), the rear end of the mass flow controller (3) is connected to a sixth air guide pipe (29), one end of the sixth air guide pipe (29) is connected to the air inlet end of the vacuum pump (4), the dryer (6) is installed between the ends of the fifth air guide pipe (28) and the sixth air guide pipe (29), the dryer (6) comprises a filling pipe (30) and a threaded cap (31), the threaded cap (31) is threadedly connected to the two ends of the filling pipe (30), the filling pipe (30) is filled with a desiccant, the threaded cap (31) is fixedly connected with a sieve plate (8), and the two threaded caps (31) are respectively connected to the fifth air guide pipe (28) and the sixth air guide pipe (29).

7. The multi-channel particulate matter wet sampling system according to claim 1, characterized in that: The control system comprises a communication line, a switch, a controller (7) and a control computer. The communication line is used to connect the controller (7) and the switch, and the switch and the control computer. The switch is connected to multiple controllers (7) at the same time. The controller (7) is installed on a bracket (20).

8. The multi-channel particulate matter wet sampling system according to claim 1, characterized in that: The control software is used by operators to remotely control and monitor the working status of the device.

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