Semi-passive air sampler

Abstract

The invention belongs to the technical field of ambient air monitoring, and provides a semi-passive air sampler which comprises a main shell, a sampling pipe is detachably connected in the main shell, the sampling pipe is filled with a gaseous pollutant adsorbent, an air entraining head is arranged above the main shell, the air entraining head is communicated with the air inlet end of the sampling pipe, and the air entraining head is communicated with the air inlet end of the sampling pipe. A lifting assembly is arranged between the air entraining head part and the main shell; the auxiliary shell is detachably connected to the main shell through a buckling piece, an air outlet channel is formed in the auxiliary shell, one end of the air outlet channel is communicated with the air outlet end of the sampling pipe, the other end of the air outlet channel is vertically communicated with an air cylinder, a solar heating mechanism is arranged in the air cylinder, and the solar heating mechanism is used for heating air at the bottom of the air cylinder; and air in the air outlet duct is driven to flow into the air duct. Passive driving can be achieved through solar energy, semi-passive air collection is achieved, and meanwhile the sampling height can be flexibly adjusted.

Description

Technical Field

[0001] This invention belongs to the field of ambient air monitoring technology, and in particular relates to a semi-passive air sampler. Background Technology

[0002] Air samplers are key equipment for air quality assessment in environmental monitoring, occupational health, and scientific research, used to collect particulate matter and gaseous pollutants from the air. Based on their sampling principles, they are mainly classified into active, passive, and semi-passive types.

[0003] Active samplers rely on an externally powered pump to actively draw air through a sampling medium (such as an adsorption tube). The sampling flow rate is stable and controllable, but the equipment is complex, costly, power-dependent, and may generate noise during operation. Passive samplers, on the other hand, rely entirely on the natural diffusion or permeation of gas molecules for sampling. They require no power supply, have a simple structure, and are easy to deploy. However, their sampling rate is greatly affected by environmental conditions (such as wind speed and temperature), the sampling volume is small, and they are usually only suitable for long-term cumulative sampling with low temporal resolution.

[0004] Semi-passive samplers fall between the two extremes, aiming to utilize natural energy (such as solar and wind power) or physical effects to enhance the sampling airflow, overcoming the low sampling rate problem of purely passive samplers while maintaining low power dependence or achieving no external power drive. However, existing semi-passive sampler designs typically suffer from complex structures, poor airflow stability, and insufficient adaptability to air sampling at different altitudes. For example, samplers utilizing the chimney effect often have unstable heat sources or require additional power, weakening the advantages of "semi-passive" operation; furthermore, their sampling inlets are usually fixed, making it difficult to flexibly adjust the sampling height according to monitoring needs, and failing to effectively reflect the differences in pollutant concentrations at different vertical levels. Summary of the Invention

[0005] The purpose of this invention is to provide a semi-passive air sampler to solve the above-mentioned problems, so as to achieve stable driving by natural energy, smooth sampling airflow, and flexible adjustment of sampling height.

[0006] To achieve the above objectives, the present invention provides the following solution: a semi-passive air sampler, comprising: The main housing has a sampling tube detachably connected inside it. The sampling tube is filled with a gaseous pollutant adsorbent. An air intake head is provided above the main housing. The air intake head is connected to the air inlet end of the sampling tube. A lifting assembly is provided between the air intake head and the main housing. The secondary housing is detachably connected to the main housing via a snap-fit ​​device. An air outlet duct is provided inside the secondary housing. One end of the air outlet duct is connected to the air outlet end of the sampling tube, and the other end of the air outlet duct is vertically connected to a wind duct. A solar heating mechanism is provided inside the wind duct to heat the air at the bottom of the wind duct, thereby driving the air in the air outlet duct into the wind duct.

[0007] Preferably, a laminar flow channel is provided inside the main housing, the laminar flow channel includes multiple microchannels, the multiple microchannels are arranged horizontally, one end of the multiple microchannels is connected to the large-diameter end of the diffuser tube, a plug tube is fixedly connected to one side wall of the main housing inward horizontally, the other end of the multiple microchannels is located in the plug tube, one end of the sampling tube is inserted into the plug tube and connected to the other end of the multiple microchannels.

[0008] Preferably, a sealing ring is fixedly connected to one end of the insertion tube near the laminar fluidization channel and the other end of the air outlet duct near the insertion tube, respectively. The two sealing rings are used to seal and connect the two ends of the sampling tube to the laminar fluidization channel and the air outlet duct, respectively.

[0009] Preferably, the air intake head includes an air inlet duct, and multiple air inlets are equally spaced on the side wall of the air inlet duct. The bottom of the air inlet duct is connected to the small-diameter end of the diffuser tube through an air intake pipe.

[0010] Preferably, the lifting assembly includes a telescopic tube vertically fixedly connected to the top of the main housing, a telescopic rod vertically slidably connected inside the telescopic tube, the telescopic rod being fixedly connected to the bottom of the air inlet duct, a drive housing fixedly connected inside the main housing, a flexible helical rack being provided inside the drive housing, one end of the flexible helical rack passing through the main housing and the telescopic tube in sequence and being fixedly connected to the telescopic rod, a gear being rotatably connected inside the drive housing, the gear meshing with the flexible helical rack, a motor being fixedly connected to the drive housing, and the gear being fixedly sleeved on the output end of the motor.

[0011] Preferably, a rack storage box is fixedly connected to the side wall of the drive housing, and the soft helical rack is disposed inside the rack storage box.

[0012] Preferably, the air intake pipe includes an outer air duct that is vertically fixedly connected to the top of the main housing, the bottom of the outer air duct is connected to the small diameter end of the diffuser, an inner air duct is slidably connected to the top of the outer air duct, and the top of the inner air duct is fixedly connected to the bottom of the air inlet duct and communicates with the inside of the air inlet duct.

[0013] Preferably, the solar heating mechanism includes a heating tube, which is disposed in the air outlet duct, located at the bottom of the air duct, and connected to a heating component.

[0014] Preferably, the heating assembly includes a heat-insulating pipe disposed within the sub-shell, one end of the heat-insulating pipe being connected to the heating pipe, and the other end of the heat-insulating pipe being connected to a flow channel. The heating pipe, the heat-insulating pipe, and the flow channel are filled with water. The assembly also includes a solar energy absorber disposed on the sub-shell, the solar energy absorber being used to heat the water in the flow channel.

[0015] Preferably, the solar absorber includes a glass box fixedly connected to the sub-shell, a solar absorber plate fixedly connected inside the glass box, a flow channel fixedly connected to the side of the solar absorber plate away from the sub-shell, a plurality of heat pipes fixedly connected to the solar absorber plate, the heat pipes being filled with a heat transfer medium, and the condensation end of the heat pipes being disposed in the flow channel for heating the liquid in the flow channel.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects: 1. This invention combines solar heating technology with the chimney effect to provide a stable driving force for the sampling airflow without the need for external power, thereby forming a continuous suction force in the sampling tube, which significantly improves the sampling rate and achieves zero power consumption operation.

[0017] 2. This invention, by incorporating a lifting component, allows users to adjust the height of the air intake head according to monitoring needs, thus facilitating air sampling at different heights. This greatly enhances the adaptability and application range of the sampler, enabling it to be used to study the vertical distribution patterns of pollutants.

[0018] 3. By setting up a main shell and a secondary shell, the present invention achieves a sealed connection of the sampling tube inside the device through the fixed connection between the two, which makes the assembly, disassembly, replacement and testing of the entire device extremely convenient and improves the ease of use. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a cross-sectional schematic diagram of the air sampler of the present invention; Figure 2 This is a cross-sectional schematic diagram of the laminar flow channel of the present invention; Figure 3 This is a schematic diagram of the solar heating element of the present invention; Figure 4 This is a schematic diagram of the drive housing and the soft helical rack of the present invention; Figure 5 This is a cross-sectional view of the drive housing of the present invention; The components are as follows: 1. Air inlet duct; 2. Air inlet; 3. Telescopic pipe; 4. Telescopic rod; 5. Inner air duct; 6. Drive housing; 7. Soft helical rack; 8. Gear; 9. Motor; 10. Outer air duct; 11. Air intake pipe; 12. Diffuser pipe; 13. Battery; 14. Laminar fluidization channel; 141. Microchannel; 15. Sampling tube; 16. Sealing ring; 17. Rack guide groove; 18. Sub-housing; 19. Air outlet duct; 20. Main housing; 21. Air duct; 22. Heating tube; 23. Insulation tube; 24. Glass box; 25. Solar absorber panel; 26. Heat transfer tube; 27. Flow channel; 28. Insertion pipe; 29. ​​Rack storage box. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] In the prior art, there is a semi-passive air sampler, which includes a particulate adsorbent, a reagent cage, a base, a blower fixed on the base, and a heater placed above the reagent cage. The heater is electrically connected to a copper plate of a power plug. The copper plate is fixed on the base. The blower covers the heater and the reagent cage and is detachably connected to the base.

[0024] The agent cage is a cylindrical, elliptical, or prismatic structure, and the material is a perforated metal plate or metal mesh.

[0025] The medicine cage is equipped with a stopper.

[0026] Its base surface is provided with a small boss for installing the agent cage and a large boss for installing the air duct. Both the large and small bosses are provided with threads or bayonet for connecting the air duct.

[0027] The air pump is shaped like a tapered chimney with several evenly distributed air inlets at the bottom. The lower edge of the air pump has threads or bayonet for connection with the base.

[0028] The heater is an electric heater with a power of 3 to 8W.

[0029] An electric heater is an electric heater composed of multiple metal film resistors.

[0030] The copper contacts of the plug are arranged symmetrically on the base, and the exposed part of the copper contacts at the bottom of the base is the same size as that of the two-prong plug of ordinary household appliances.

[0031] In this technical solution, instead of placing the air inlet on the blower tube, evenly distributed recesses can be set on the large protrusion of the base. When the blower tube is connected to the base, the wall of the blower tube and the recesses on the base constitute the air inlet, which serves the same function as the air inlet mentioned above.

[0032] The granular adsorbent is activated carbon or molecular sieve; the base is made of polytetrafluoroethylene or food-grade polyethylene; the air duct is made of polytetrafluoroethylene or food-grade polyethylene.

[0033] This technical solution has a simple structure, small size, low price, no mechanical wear or pollution gas emission during sampling, and a long service life. It is easy to operate, and home users can sample themselves. It has high detection efficiency and low operating cost. Based on a heating power of 5 watts and a sampling time of 2 hours, each sampling consumes only 0.01 kWh of electricity.

[0034] Reference Figures 1-5 The present invention provides a semi-passive air sampler, comprising: The main housing 20 has a sampling tube 15 detachably connected inside it. The sampling tube 15 is filled with a gaseous pollutant adsorbent. An air intake head is provided above the main housing 20. The air intake head is connected to the air inlet end of the sampling tube 15. A lifting component is provided between the air intake head and the main housing 20. The secondary housing 18 is detachably connected to the main housing 20 via a snap fastener. An air outlet 19 is provided inside the secondary housing 18. One end of the air outlet 19 is connected to the air outlet of the sampling tube 15, and the other end of the air outlet 19 is vertically connected to a wind duct 21. A solar heating mechanism is provided inside the wind duct 21 to heat the air at the bottom of the wind duct 21, thereby driving the air in the air outlet 19 into the wind duct 21.

[0035] The sampling tube 15 can be filled with absorbents or adsorbents for specific gases, such as SO2, NOx, and VOCs. Gas molecules can be captured by the absorbent or adsorbent after entering the sampling tube 15. The main function of the air intake head is to collect air at its current height so that air at the target height can enter the sampling tube 15. The main function of the lifting assembly is to adjust the height of the air intake head. The main function of the fastener is to connect and separate the sub-shell 18 and the main shell 20. When the sub-shell 18 is separated from the main shell 20, the sampling tube 15 can be removed from the main shell 20. The main function of the air duct 21 is to work with the solar heating mechanism to create a chimney effect on the side of the air outlet 19 away from the sampling tube 15. By heating the air at the bottom of the air duct 21, the air rises from the hot air duct 21, thereby creating a negative pressure in the air outlet 19 and forcing the air to enter the sampling tube 15 through the air intake head. Overall, this invention utilizes the chimney effect and solar energy to drive air into the sampling tube through the rational use of natural energy, achieving semi-passive sampling. At the same time, the sampling height can be flexibly adjusted, which helps to study the vertical distribution patterns of pollutants.

[0036] The snap-fit ​​component is a common structure that can securely connect the main housing 20 and the secondary housing 18, so the structure of the snap-fit ​​component will not be further explained.

[0037] Further optimization of the scheme: a laminar flow channel 14 is provided inside the main shell 20. The laminar flow channel 14 includes multiple microchannels 141, which are arranged horizontally. One end of the multiple microchannels 141 is connected to the large-diameter end of the diffuser tube 12. A insertion tube 28 is fixedly connected to the side wall of the main shell 20 inwardly. The other end of the multiple microchannels 141 is located inside the insertion tube 28. One end of the sampling tube 15 is inserted into the insertion tube 28 and connected to the other end of the multiple microchannels 141.

[0038] In this embodiment, as Figure 2 As shown, the laminar flow channel 14 is formed by multiple parallel microchannels 141 fixedly connected to each other to form a honeycomb structure. By setting the microchannels 141, the air flowing through this channel forms a laminar flow, which greatly reduces the random interference of the airflow on the subsequent diffusion and adsorption process, and allows gas molecules to be captured in the sampling tube 15 at a stable diffusion rate.

[0039] In a further optimized design, sealing rings 16 are fixedly connected to one end of the insertion tube 28 near the laminar flow channel 14 and the other end of the air outlet 19 near the insertion tube 28. The two sealing rings 16 are used to seal and connect the two ends of the sampling tube 15 to the laminar flow channel 14 and the air outlet 19, respectively.

[0040] like Figure 1As shown, the air inlet of the air outlet duct 19 is located on the side wall of the secondary housing 18 near the main housing 20. The end of the insertion pipe 28 away from the laminar fluidization channel 14 is located on the side wall of the main housing 20 near the secondary housing 18. A sealing ring 16 is fixed to the air inlet of the air outlet duct 19, and another sealing ring is fixed inside the insertion pipe 28 and fits against the laminar fluidization channel 14. The sampling tube 15 is horizontally inserted into the insertion pipe 28 from the outside of the main housing 20 and then connected to the secondary housing 18. At this time, the left end of the sampling tube 15 abuts against the sealing ring 16 on the left side, and its right end is sealed and connected to the air outlet duct 19 through the sealing ring 16 on the right side. After the secondary housing 18 is removed from the main housing 20, the sampling tube 15 can be taken out from the insertion pipe 28.

[0041] Further optimization of the scheme: the air intake head includes an air inlet duct 1, and multiple air inlets 2 are evenly spaced on the side wall of the air inlet duct 1. The bottom of the air inlet duct 1 is connected to the small diameter end of the diffuser 12 through an air intake pipe fitting.

[0042] like Figure 1 As shown, multiple air inlets 2 can evenly introduce the air surrounding the air inlet duct 1 into the air intake pipe.

[0043] The design is further optimized. The lifting assembly includes a telescopic tube 3 vertically fixedly connected to the top of the main housing 20. A telescopic rod 4 is vertically slidably connected inside the telescopic tube 3. The telescopic rod 4 is fixedly connected to the bottom of the air inlet duct 1. A drive housing 6 is fixedly connected inside the main housing 20. A soft helical rack 7 is provided inside the drive housing 6. One end of the soft helical rack 7 passes through the main housing 20 and the telescopic tube 3 in sequence and is fixedly connected to the telescopic rod 4. A gear 8 is rotatably connected inside the drive housing 6. The gear 8 meshes with the soft helical rack 7. A motor 9 is fixedly connected to the drive housing 6. The gear 8 is fixedly sleeved on the output end of the motor 9.

[0044] In a further optimized design, a rack storage box 29 is fixedly connected to the side wall of the drive housing 6, and a soft helical rack 7 is disposed inside the rack storage box 29.

[0045] To further optimize the design, a rack guide groove 17 is provided inside the drive housing 6, and the rack guide groove 17 is correspondingly set to the free end of the soft helical rack 7.

[0046] like Figure 4 , Figure 5 As shown, the soft helical rack 7 is made of soft plastic. When it enters the telescopic tube 3, it can straighten smoothly according to the shape of the telescopic tube 3. When it is pulled down from the telescopic tube 3, it can automatically curl into a spiral shape. The rack guide groove 17 can guide the soft helical rack 7 into the rack storage box 29, so that the soft helical rack 7 is stored in the rack storage box 29. By setting the rack storage box 29, the rack can avoid collision and interference with other components in the main housing 20.

[0047] When it is necessary to raise the air inlet duct 1, the motor 9 can be controlled to rotate. The rotation of the motor 9 drives the gear 8 to rotate, and the gear 8, through meshing, pushes the soft helical rack 7 into the telescopic tube 3. As the soft helical rack 7 continuously enters the telescopic tube 3, it pushes the telescopic rod 4 upward along the telescopic tube 3, thereby raising the air inlet duct 1. When it is necessary to lower the height of the air inlet duct 1, the motor 9 can be controlled to reverse.

[0048] In a further optimized design, a battery 13 is installed inside the main housing 20 to provide power for the operation of the motor 9. The main housing 20 also has control buttons (not shown in the figure) for controlling the forward and reverse rotation of the motor 9.

[0049] Further optimization of the scheme: the air intake pipe includes an outer air duct 10 that is vertically fixedly connected to the top of the main housing 20. The bottom of the outer air duct 10 is connected to the small diameter end of the diffuser 12 through the air intake pipe 11. An inner air duct 5 is slidably connected to the top of the outer air duct 10. The top of the inner air duct 5 is fixedly connected to the bottom of the air inlet duct 1 and communicates with the inside of the air inlet duct 1.

[0050] like Figure 1 As shown, the inner air duct 5 can extend and retract synchronously within the outer air duct 10 as the height of the air inlet duct 1 is adjusted, ensuring a sealed connection between the two. At the same time, the inner air duct 5 and the outer air duct 10 form a flow channel stabilization cavity, which buffers external turbulence through a large volume, forming a preliminary stable flow field.

[0051] The scheme is further optimized. The solar heating mechanism includes a heating tube 22, which is installed in the air outlet duct 19. The heating tube 22 is located at the bottom of the air duct 21 and is connected to a heating component.

[0052] The design is further optimized. The heating component includes an insulation pipe 23 installed in the sub-shell 18. One end of the insulation pipe 23 is connected to the heating pipe 22, and the other end of the insulation pipe 23 is connected to a flow channel 27. The heating pipe 22, the insulation pipe 23 and the flow channel 27 are filled with water. The heating component also includes a solar energy absorber installed on the sub-shell 18. The solar energy absorber is used to heat the water in the flow channel 27.

[0053] like Figure 1 and Figure 3 As shown, the water temperature in the flow channel 27 rises, which gradually raises the water temperature in the insulation pipe 23, thereby forming a high-temperature area at the bottom of the air duct 21, heating the air therein, and driving the air out from the top of the air duct 21.

[0054] In a further optimized design, the solar absorber includes a glass box 24 fixedly connected to the sub-shell 18, a solar absorber panel 25 fixedly connected inside the glass box 24, a flow channel 27 fixedly connected to the side of the solar absorber panel 25 away from the sub-shell 18, a plurality of heat pipes 26 fixedly connected to the solar absorber panel 25, the heat pipes 26 being filled with a heat transfer medium, and the condensation end of the heat pipes 26 being located inside the flow channel 27 for heating the liquid inside the flow channel 27.

[0055] In this embodiment, the glass box 24 is inclinedly mounted on the outer wall of the sub-shell 18. Under sunlight, the solar absorber 25 absorbs solar radiation heat, heating the working fluid in the heat pipe 26. After the working fluid evaporates, it releases heat at the condenser end, heating the water in the flow channel 27. The heated water circulates to the heating pipe 22 under thermosiphon action, continuously heating the air flowing over it.

[0056] The working process of this embodiment is as follows: During operation, the sampler is placed at the monitoring point. The motor 9 is controlled to raise or lower the air intake duct 1 to a designated position; in this embodiment, it is raised to 1.5 meters above the ground, at the height of the human breathing zone. By adjusting the air intake duct 1 to different heights, air samples from different layers can be collected.

[0057] Sunlight irradiates the glass chamber 24, gradually increasing the temperature of the heating tube 22. The air flowing through the heating tube 22 is heated, its density decreases, and the hot air rises within the air duct 21, creating a chimney effect. This stable upward airflow creates negative pressure within the outlet duct 19 and the sampling tube 15. Ambient air enters through the inlet 2 of the inlet duct 1, passes through the inner air duct 5 and the outer air duct 10, and reaches the diffuser 12, where the airflow is initially buffered. It then enters multiple microchannels 141 of the laminar flow channel 14, where turbulence is eliminated, transforming into a stable laminar flow. This stable laminar flow finally enters the sampling tube 15, flowing through the adsorbent within, where gaseous pollutants are captured. Afterward, the air continues to flow through the outlet duct 19, reaches the heating tube 22 for further heating, and finally exits from the top of the air duct 21, completing the entire sampling cycle.

[0058] After sampling is completed, disconnect the latch between the main housing 20 and the secondary housing 18 to easily remove the sampling tube 15 and send it to the laboratory for analysis.

[0059] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0060] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A semi-passive air sampler, characterized in that, include: The main housing (20) has a sampling tube (15) detachably connected inside it. The sampling tube (15) is filled with a gaseous pollutant adsorbent. An air intake head is provided above the main housing (20). The air intake head is connected to the air inlet end of the sampling tube (15). A lifting assembly is provided between the air intake head and the main housing (20). The secondary housing (18) is detachably connected to the main housing (20) by a snap fastener. An air outlet duct (19) is provided inside the secondary housing (18). One end of the air outlet duct (19) is connected to the air outlet end of the sampling tube (15). The other end of the air outlet duct (19) is vertically connected to a wind duct (21). A solar heating mechanism is provided inside the wind duct (21). The solar heating mechanism is used to heat the air at the bottom of the wind duct (21) to drive the air in the air outlet duct (19) into the wind duct (21).

2. The semi-passive air sampler according to claim 1, characterized in that: The main housing (20) is provided with a laminar flow channel (14), which includes multiple microchannels (141). The multiple microchannels (141) are arranged horizontally, and one end of the multiple microchannels (141) is connected to the large-diameter end of the diffuser (12). A plug tube (28) is fixedly connected to one side wall of the main housing (20) inwardly. The other end of the multiple microchannels (141) is located in the plug tube (28). One end of the sampling tube (15) is inserted into the plug tube (28) and connected to the other end of the multiple microchannels (141).

3. A semi-passive air sampler according to claim 2, characterized in that: A sealing ring (16) is fixedly connected to one end of the insertion tube (28) near the laminar flow channel (14) and the other end of the air outlet (19) near the insertion tube (28). The two sealing rings (16) are used to seal and connect the two ends of the sampling tube (15) to the laminar flow channel (14) and the air outlet (19) respectively.

4. A semi-passive air sampler according to claim 2, characterized in that: The air intake head includes an air inlet duct (1), and multiple air inlets (2) are equally spaced on the side wall of the air inlet duct (1). The bottom of the air inlet duct (1) is connected to the small diameter end of the diffuser (12) through an air intake pipe.

5. A semi-passive air sampler according to claim 4, characterized in that: The lifting assembly includes a telescopic tube (3) vertically fixedly connected to the top of the main housing (20), a telescopic rod (4) vertically slidably connected inside the telescopic tube (3), the telescopic rod (4) being fixedly connected to the bottom of the air inlet (1), a drive housing (6) fixedly connected inside the main housing (20), a soft helical rack (7) provided inside the drive housing (6), one end of the soft helical rack (7) passing through the main housing (20) and the telescopic tube (3) in sequence and being fixedly connected to the telescopic rod (4), a gear (8) rotatably connected inside the drive housing (6), the gear (8) meshing with the soft helical rack (7), a motor (9) fixedly connected to the drive housing (6), and the gear (8) fixedly sleeved on the output end of the motor (9).

6. A semi-passive air sampler according to claim 5, characterized in that: A rack storage box (29) is fixedly connected to the side wall of the drive housing (6), and the soft helical rack (7) is disposed inside the rack storage box (29).

7. A semi-passive air sampler according to claim 5, characterized in that: The air intake pipe includes an outer air duct (10) that is vertically fixed to the top of the main housing (20). The bottom of the outer air duct (10) is connected to the small diameter end of the diffuser (12). An inner air duct (5) is slidably connected to the top of the outer air duct (10). The top of the inner air duct (5) is fixedly connected to the bottom of the air inlet duct (1) and communicates with the inside of the air inlet duct (1).

8. A semi-passive air sampler according to claim 1, characterized in that: The solar heating mechanism includes a heating tube (22), which is disposed in the air outlet duct (19). The heating tube (22) is located at the bottom of the air duct (21), and the heating tube (22) is connected to a heating component.

9. A semi-passive air sampler according to claim 8, characterized in that: The heating assembly includes a heat-insulating pipe (23) disposed in the sub-shell (18), one end of which is connected to the heating pipe (22), and the other end of which is connected to a flow channel (27). The heating pipe (22), the heat-insulating pipe (23), and the flow channel (27) are filled with water. The assembly also includes a solar energy absorber disposed on the sub-shell (18), which is used to heat the water in the flow channel (27).

10. A semi-passive air sampler according to claim 9, characterized in that: The solar absorber includes a glass box (24) fixedly connected to the sub-shell (18), a solar absorber plate (25) fixedly connected inside the glass box (24), a flow channel (27) fixedly connected to the side of the solar absorber plate (25) away from the sub-shell (18), a plurality of heat pipes (26) fixedly connected to the solar absorber plate (25), the heat pipes (26) being filled with a heat transfer medium, and the condensing end of the heat pipes (26) being located inside the flow channel (27) for heating the liquid inside the flow channel (27).

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