Air pollutant sampling equipment

Abstract

To provide a compact device which is hard to break down and samples pollutants in the atmosphere at regular intervals.SOLUTION: An air pollutant sampling device includes in a housing 1 two or more impingers 2 that collect pollutants in the atmosphere through two ventilation pipes, one ventilation pipe provided with an air pump 33, and a connection switching mechanism that, after maintaining a connection between the ventilation pipe on one of the air pump sides and the ventilation pipe on the impinger side to be sampled for a certain period of time, sequentially switches the connection between the ventilation pipe on the air pump side and the ventilation pipe on the impinger side to the connection with the ventilation pipe on the other impinger side at the same time as the start of other sampling. The connection switching mechanism inserts a rotating inner cylinder 50 into a fixed outer cylinder 40 in which the rotating inner cylinder is slidable and substantially equivalent in outer diameter to the fixed outer cylinder, each through hole connecting the ventilation pipes on each collection container side is drilled at regular intervals on the same circumference of an inner cylinder wall of the fixed outer cylinder, and a through hole connecting the ventilation pipes on the air pump side is provided at a position of the cylinder wall of the rotating inner cylinder where it can communicate with each ventilation pipe on the collection container side.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus for sampling atmospheric pollutants. [Background technology]

[0002] In places where air pollution caused by factory emissions or automobile exhaust fumes is a concern, air pollution levels are monitored continuously. The pollutants can be detected by sampling them from the air into a liquid and analyzing the sampled liquid. To collect airborne pollutants, a sampling device called an impinger is typically used, which collects the pollutants in a liquid. The impinger is a device that pumps air into a sample liquid in a container to generate small air bubbles, which trap contaminants contained in the air on the surface of the bubbles in the sample liquid.

[0003] Air sampling using this impinger involves continuing to send air into the sampling liquid for a certain period of time using a set number of impingers, during which time pollutants are accumulated in the sampling liquid, and when the set time has passed, switching to the next impinger and continuing collection for another set period of time.By repeating this process, the impingers which have collected pollutants in turn are recovered at set time intervals, and the sampled liquid is analyzed, making it possible to grasp the changes in air pollution over time.

[0004] For example, in the device described in Patent Document 1 below, automatic valves are provided in the pipes that send air to the impingers, the number of which corresponds to the number of samples to be sampled, and a microswitch is used to automatically open one of the valves in sequence and close the others. While the valves are open, a motor is used to operate a pump to collect contaminants. However, with this device, there is a risk that operating the automatic valves for long periods of time will cause them to heat up and malfunction, and there is also a concern that the probability of failure will increase as the number of automatic valves increases in accordance with the number of samples. In addition, in recent years, there has been a demand for more compact and inexpensive equipment that can be easily installed in factories and the like that generate soot that causes air pollution, and that allows collected samples to be easily transported to testing institutions, etc.; however, with the above-mentioned equipment, the more impingers there are, the more automatic valves must be used, which results in problems such as larger equipment and higher manufacturing costs, and the reality is that it is not possible to meet these demands. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 52-34954 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and provides a compact, trouble-free sampling device for air pollutants that can automatically and reliably switch between sending air to each impinger in sequence without using valves when sending air to each impinger, and that can continuously sample air pollutants at regular intervals. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a sampling device for air pollutants, comprising: a) a sampling vessel having one end immersed in a sampling liquid and the other end facing an upper space; And the end of the intake pipe is connected to the intake pipe Two or more impingers that collect pollutants in the air through the impinger, and b) one impinger that controls the intake or delivery of air. Exhaust pipe Equipped with Suction type An air pump, and c) one of the air pumps Exhaust pipe and 2 or more impingers Air supply pipe The connection to the air pump side Exhaust pipe and the number of impingers to be sampled. Air supply pipe After maintaining this for a certain period of time, the other sampling is started at the same time as Exhaust pipeand other impingers. Air supply pipe and (d) a control unit for controlling the timing of switching the connection between the impinger side and the air pump side, the connection switching mechanism being provided in a housing, the connection switching mechanism being provided with a cylindrical fixed outer barrel fixed to the housing, a cylindrical rotating inner barrel of approximately the same outer diameter as the fixed outer barrel, the inner circumferential surface of which is slidable against the outer circumferential surface of the fixed outer barrel, and a cylindrical rotating inner barrel of approximately the same outer diameter as the fixed outer barrel is provided on the cylindrical wall of the fixed outer barrel. Air supply pipe The through holes are formed at regular intervals on the same circumference, and the wall of the rotating inner cylinder fitted to the fixed outer cylinder is provided with an air pump side Exhaust pipe The through holes on the sampling container side are connected to each other. Air supply pipe and the nozzle is drilled at a position that allows communication by the rotation of the rotating inner cylinder. The exhaust pipe is provided to extend upward from a cylinder center position of the connection switching mechanism, The present invention is characterized in that it comprises:

[0008] The invention described in claim 2 is characterized in that, in the above invention, a disk gear having a common center of rotation with the rotating inner cylinder is fixed to the upper end of the rotating inner cylinder, and the rotating inner cylinder can be rotated by rotating the disk gear by a motor.

[0009] The invention described in claim 3 is the above invention, wherein the air pump side Exhaust pipe is characterized by having a disc gear that penetrates the center and is made of a flexible material that can be twisted and deformed.

[0010] The invention described in claim 4 is the above invention, wherein the central portion of the disk gear is on the air pump side. Exhaust pipe The gear is divided into upper and lower halves, and a rotational connection part that connects the upper part to the lower part so as to be freely rotatable is provided at the center of the disc gear.

[0011] The invention described in claim 5 is characterized in that, in the above invention, an O-ring is attached to the opening on the outer circumferential side of the through hole of the rotating inner cylinder body to prevent air flow between the inside and outside of the through hole. Effect of the Invention

[0012] In the air pollutant sampling device of the present invention, air pollutants are collected continuously at regular intervals using an impinger by switching the connection between two or more impinger side vent pipes and one air pump side vent pipe using a connection switching mechanism, and the connection switching mechanism is a reliable and simple mechanism that rotates a cylindrical body. In addition, since the motor operates for only a very short time while rotating, it uses little power and does not generate heat to the point where it becomes very hot, so there is no risk of operational problems due to heat generation. Furthermore, even if the number of samples increases, the number of connections simply increases accordingly, and there is no increase in the number of parts such as valves, and there is no increase in the probability of failure. In addition, since the size of the device does not increase, the collected samples can be easily carried, and the cost of the device can be reduced.

[0013] According to the invention recited in claim 2, the disk gear provided at the upper end of the rotating inner cylinder is rotated by a motor, whereby the rotating inner cylinder can be rotated reliably. This is a simple mechanical structure that combines a motor and gears, and is less prone to malfunctions.

[0014] In the invention described in claim 3, if the vent pipe on the air pump side passes through the center of the disk gear, when the rotating inner cylinder is rotated, if the end side of the vent pipe is fixed, twisting will occur in the middle of the vent pipe. However, by making the vent pipe out of a flexible material, it is possible to accommodate the twisting and ensure a normal air passage.

[0015] In the invention described in claim 4, when the vent pipe on the air pump side is fixed through the center of the disk gear, if the vent pipe is hard, the rotating inner cylinder cannot rotate. However, by dividing the hard vent pipe into upper and lower parts at the disk gear portion and providing a rotating connection part that connects the upper side to the lower side so that it can rotate freely, the rotating inner cylinder becomes rotatable, and the connection switching mechanism functions normally to maintain the air passage of the vent pipe normally.

[0016] In the invention described in claim 5, an O-ring is attached to the opening on the outer circumferential side of the through hole of the rotating inner cylinder, thereby sealing the gap that occurs between the through holes connecting the vent pipe on the air pump side and the vent pipe on the impinger side, thereby making it possible to prevent air from flowing between the inside and outside of the through holes when the air in both through holes is pressurized or depressurized by the air pump. As a result, it is possible to pump a precise amount of air into the collection container and into the collected liquid, controlled by the air pump. [Brief description of the drawings]

[0017] [Figure 1] A perspective view of the present invention. [Diagram 2] FIG. 2 is a horizontal cross-sectional view of the present invention. [Diagram 3] FIG. 2 is a vertical sectional side view of a main part showing the inside of the housing on the impinger side. [Figure 4] 4 is a vertical sectional side view of a main part showing the inside of a housing on the connection switching mechanism side. FIG. [Diagram 5] 4 is a horizontal cross-sectional view of a main portion showing a through-hole and its surrounding area of ​​the connection switching mechanism. FIG. [Figure 6] 11 is a perspective view showing a state in which a fixed outer cylinder body and a rotating inner cylinder body of the connection switching mechanism are separated from each other. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Figure 1, the air pollutant sampling device of the present invention comprises, within a housing 1, a container support section 12 that supports sampling containers 21 of impingers 2 for two or more samples, and a connection switching mechanism 3 that switches the flow path of air sent to each impinger 2 in sequence. As shown in FIGS. 3 and 4, the housing 1 has a bottom plate 13 and is box-shaped with an open top for inserting and removing the impinger 2. A cover (not shown) may be provided on the top of the housing 1 to prevent dust from entering.

[0019] As shown in FIG. 3, the impinger 2 used in the present invention is a test-tube-shaped glass sampling container 21 into which sampling liquid A for collecting airborne pollutants such as water is poured so that there is space at the top, and the impinger 22 comprises a two-hole plug 22 having holes for passing two vent pipes therethrough, and two vent pipes inserted into the holes. One of the two vent pipes is inserted into one of the holes 22b of the two-hole plug until its tip opening is close to the bottom of the collection container 21, and is attached in a state immersed in the collection liquid A contained in the collection container 21.

[0020] The other vent tube is inserted into the other hole 22a so that its tip opening is not submerged in the collection liquid A in the space above the collection container 21 closed by the two-hole plug. For example, as shown in FIG. 3, a sampling liquid A for collecting atmospheric pollutants such as water is poured into a sampling container 21, which is a test-tube type glass container, so that there is space at the top. Small air bubbles are generated in the collected liquid A from the tip of an aeration tube immersed in the collected liquid A. To this end, air in the upper space is sucked in through a ventilation tube having a tip opening disposed in the upper space of the collection container 21 to reduce the pressure, or air is pumped to the tip opening of a ventilation tube immersed in the collection liquid A. During this process, as the bubbles rise into the collected liquid, contaminants contained in the bubbles are captured in the collected liquid from the bubble surfaces.

[0021] As described above, the flow of air compressed through the vent pipe generates small air bubbles in the collected liquid A, so it flows in one direction toward the tip of the vent pipe immersed in the collected liquid A. When the air pump that moves air into the pipe is installed on the vent pipe immersed in the collected liquid A, it is installed on the atmospheric intake side and reduces the pressure by sucking in the air in the upper space. of If installed on the ventilation pipe, it should be installed on the exhaust side that exhausts the air after collecting pollutants. Possible modes . Regardless of which side the air pump is installed on, it is possible to generate air bubbles in the sample liquid and collect contaminants. In the present invention, the latter method is adopted in consideration of the characteristics of the impinger.Hereinafter, the present invention will be described in detail based on the case where the air pump reduces the pressure by sucking air in the upper space through an air pipe having a tip port disposed in the upper space of the sampling container 21.

[0022] In the present invention, the ventilation pipe includes three pipes: an intake pipe that draws in the air to be sampled, an exhaust pipe that discharges the air after collecting pollutants into the atmosphere, and an air supply pipe that sends air from the intake pipe to the exhaust pipe. In this embodiment, the vent pipe on the impinger 2 side has one end open to the atmosphere and its tip immersed in the sampled liquid A, which is designated as the intake pipe 25, and the other end that draws in air from its tip to reduce the pressure in the upper space is designated as the air supply pipe 23. In addition to the two vent pipes on the impinger 2 side, there is one vent pipe equipped with an air pump for pressurizing air into the above vent pipes; this vent pipe is referred to as exhaust pipe 31, and this term will be used hereinafter to describe the vent pipes.

[0023] As shown in Figs. 1 and 2, the housing 1 may be configured in such a manner that an area supporting the sampling container 21 and an area having the connection switching mechanism are separated by an upright partition wall 11. In this embodiment, a container support plate 12a is provided in the area where the sampling containers 21 are located to divide the internal space into upper and lower sections, and container insertion holes 12b of a diameter that allows the sampling containers 21 corresponding to two or more samples to be inserted from above into the container support plate 12a and supported upright on the bottom plate 13, and pipe passage holes 12c of a number sufficient to insert all of the tubes to be attached in pairs to the two holes of the two-hole cover 22 according to the number of sampling containers 21. 1 and 2 show an apparatus having seven container insertion holes 12b for sampling, for example, one week's worth of samples using the impinger 2. Moreover, if 31 container insertion holes 12b are provided, one month's worth of collection containers 21 can be supported.

[0024] A pipe hole 11a is provided in the partition wall 11 of the housing 1 so that the air supply pipe 23 of each sampling container 21 extends beyond the partition wall 11 of the housing 1 to the area where the connection switching mechanism is located, and the air supply pipe 23 passes through the pipe hole 11a. Also, the end of the intake pipe 25 teeth, As shown in Figure 2, It is connected to the collecting intake pipe 27, An intake port 28 is protruded from the middle of the housing 1 through the side wall via a collecting intake pipe 27. This is the situation. . FIG. 3 shows an embodiment in which the individual intake pipes 25 are connected to gather into a single thick collective intake pipe 27.

[0025] The air supply pipe 23 and the air intake pipe 25 are provided with detachable joints 24, 26 at their ends, which are connectable and detachable, leaving a portion protruding from the sampling container 21 above the container insertion hole 12b. When sampling is completed and the sampling container 21 is removed from the housing 1, the air supply pipe 23 and the detachable joints 24, 26 are detached from the detachable joints 24, 26. Intake pipe 25 The detachable joints 24, 26 are attached so that the collection container 21 can be removed from the housing 1 with the plug still attached. Intake pipe 25 By attaching and detaching the sampling container 21 midway, it is easy to replace the sampling container 21 that has been used for sampling with a new one.

[0026] The structure on the impinger 2 side has been described above. Next, the structure on the connection switching mechanism 3 side will be described. As shown in Figures 4 and 6, the connection switching mechanism 3 is a mechanism formed at the junction that connects the exhaust pipe 31, which exhausts collected air from the exhaust port 31b to the atmosphere, to each air supply pipe 23 on the impinger 2 side, and is structured to have the function of sequentially switching and connecting one exhaust pipe 31 to one of two or more air supply pipes 23 leading to the collection containers 21 of two or more impingers 2.

[0027] As shown in FIG. 4, the structure is such that the fixed outer cylinder 40 is fixed upright on the bottom plate 13 of the housing 1, and the rotating inner cylinder 50 is fitted into the fixed outer cylinder 40 so as to be freely rotatable around a common center line X within the fixed outer cylinder 40. The inner diameter of the fixed outer cylinder 40 and the outer diameter of the rotating inner cylinder 50 are approximately the same diameter so that the opposing inner wall surface 40a of the fixed outer cylinder 40 and the outer wall surface 50a of the rotating inner cylinder 50 are in close contact with each other. When the fixed outer cylinder body 40 is rotated, the inner peripheral surface 40a and the outer peripheral surface 50a of the fixed outer cylinder body 40 slide against each other, but a gap is minimized between the opposing peripheral surfaces 40a, 50a.

[0028] The height of the rotating inner cylinder 50 is made smaller than that of the fixed outer cylinder 40, and a disk gear 52 having a gear 52a with a diameter slightly larger than the outer diameter of the rotating inner cylinder 50 is fixed to the upper end of the rotating inner cylinder 50 so that its center of rotation is common to the center line X of the rotating inner cylinder 50. As shown in FIG. 6, a transmission gear 53 is provided between the disk gear 52 and a motor 54 provided on the outside of the fixed outer cylinder 40, so that the rotating inner cylinder 50 can be rotated by the motor 54 either directly or via the transmission gear 53.

[0029] Further, a center hole 52b is provided in the center of the disk gear 52, and the exhaust pipe 31 passes through the center hole 52b to support the middle portion of the exhaust pipe 31. As shown in FIG. 4, the tip side of the exhaust pipe 31 protruding below the disc gear 52 is curved toward the inner wall surface 51b of the rotating inner cylinder 50, and the connection port 31a at the tip is connected to a through hole 51 penetrating the peripheral wall of the rotating inner cylinder 50. The end side of the intake pipe 31 protruding above the disc gear 52 has an air pump 33 provided midway, and an exhaust port 31b that discharges air into the atmosphere protrudes upward from the air pump 33.

[0030] The exhaust pipe 31 passes through the center of the disc gear 52 and its middle part is supported by the disc gear 52 of the rotating inner cylinder 50. When the rotating inner cylinder 50 is rotated, if the end side of the exhaust pipe 31 is fixed to the air pump, a twist will occur in the middle of the exhaust pipe 31. Therefore, if the exhaust pipe 31 is made of a flexible material such as a rubber tube, the exhaust pipe 31 can flexibly deform to ensure a smooth airway and allow air to flow normally even if it is twisted by the rotation of the rotating inner cylinder 50. In this case, if the exhaust pipe 31 is short, there is a possibility that the pipe will be crushed midway through when it is rotated significantly, narrowing the flow path, so the length of the exhaust pipe 31 needs to be long enough to avoid crushing according to the size of the rotation angle. In this case, after sampling is completed, the rotating inner cylinder 50 is rotated in the reverse direction and reset to the original starting position.

[0031] Alternatively, if the exhaust pipe 31 is made of a pipe material such as hard plastic or metal, the exhaust pipe 31 can be divided into upper and lower parts from the middle of the disc gear 52, and a rotating connection part 56 can be provided so that the upper part is connected to the lower part so that it can rotate freely. This makes it possible to rotate the disc gear 52 smoothly without any torsional deformation of the exhaust pipe 31 that occurs as the rotating inner cylinder 50 rotates. The rotating connection portion 56 can be constructed, for example, by combining both ends of the separated exhaust pipe 31 so that one pipe portion formed with a large diameter and the other pipe portion formed with a small diameter are rotatably fitted together, and the fitted parts are surrounded by a frame that supports the periphery so as to prevent them from separating. In this case, after sampling is completed, the rotating inner cylinder 50 can be rotated once without changing the rotation direction and reset to the original start position.

[0032] The fixed outer cylinder 40 has through holes 41 drilled at a constant angle on the same circumference, the number of which corresponds to the number of samples to be collected, and the connection port 23b at the end of the air supply pipe 23 connected to the impinger 2 is connected to the outer opening of the through hole 41 from the outside of the fixed outer cylinder 40. The height position of the center of the through hole 51 that penetrates the peripheral wall of the rotating inner cylinder 50 is positioned so that it is at the same height as the height position of the center of the through hole 41 of the fixed outer cylinder 40 when it is inserted from above the fixed outer cylinder 40 and the mounting surface 52 of the underside of the disk of the disk gear 52 of the fixed outer cylinder 40 is placed on the upper end surface 40c of the fixed outer cylinder 40, and the hole is drilled at that position. In other words, the central position of the through hole 51 moves as the rotating inner cylinder 50 rotates, but when it reaches the center of all the through holes 41 of the fixed outer cylinder 40, the through holes 41, 51 on both sides overlap each other and become capable of communicating with each other.

[0033] As shown in FIG. 5, an elastic O-ring 55 for preventing air leakage is attached to the opening on the outer circumferential side of the through hole 51 of the rotating inner cylinder 50 so that the O-ring 55 is pressed against the inner circumferential wall surface 4a of the fixed outer cylinder 40. As a result, air sucked by the air pump 33 does not enter the connecting portion of the through holes 41, 51 on both sides, and a precisely controlled amount of air can be sent to the sampling container 21.

[0034] In the device of the present invention, the motor 54 that rotates the disk gear 52 and the motor built into the air pump 33 that draws in air are electrically controlled and operated. The motor 54 that rotates the disk gear 52 is electrically controlled by a control unit 6 that includes rotation control electronic components 61 that switch the connection between the exhaust pipe 31 and each of the air supply pipes 23 by the connection switching mechanism 3. For example, the rotating cylinder 50 is moved by a certain angle once a day by the motor 54 so that it stops at a position where the through holes 41, 51 on both sides can communicate, and the operation of the motor 54 is controlled so that the motor 54 stops at a position where the center position of the through hole 41 in the fixed cylinder 40 and the center position of the through hole 51 in the rotating cylinder 50 exactly coincide with each other. In addition, the air pump 33 is either switched on and continues to operate continuously, or is controlled in conjunction with the control of the motor 54 so that it stops operating only when the connection between the exhaust pipe 31 and each of the air supply pipes 23 is being switched. As a result, one day's worth of sampling can be performed for one collection container 21, and if seven impingers 2 are provided, sampling can be performed for each collection container 21 for consecutive days over one week.

[0035] As described above, the connection switching mechanism 3 is provided between the air supply pipe 23 and the exhaust pipe 31, so that the air before sampling can be sampled directly from the intake pipe 25 without passing it through the air pump 33. As a result, the air remaining in the air pump 33 before switching is prevented from being mixed into the new sampling container 21, making it possible to accurately sample contaminants.

[0037] In the sampling device of the present invention as described above, the connection switching mechanism 3 allows the sampling of air pollutants using two or more impingers 2 to be smoothly switched between a single exhaust pipe 31 and a plurality of air supply pipes 23, and sampling is performed continuously at regular intervals.In this case, the connection switching mechanism 3 rotates the rotatable inner cylinder 50 inside the fixed outer cylinder 40, and the motor 54 only operates for a very short time during rotation, so little electricity is used. The connection switching mechanism 3 has a double cylindrical structure consisting of a fixed outer cylinder 40 and a rotating inner cylinder 50, and a single communication hole is formed between one exhaust pipe 31 and two or more air supply pipes 23 by connecting the communication holes on both sides, and operation is reliable and simple with a simple switching operation of rotating the rotating inner cylinder. In addition, the combination of the fixed outer cylinder 40 and the rotating inner cylinder 50 does not use valves, so there is no risk of malfunction due to heat generation during operation, and the extremely simple structure makes it difficult to break and easy to disassemble and assemble, which makes maintenance such as washing and cleaning easy.

[0038] Furthermore, when increasing the number of samples, the number of impingers 2 must be increased accordingly, but there is no need to increase the number of other components; the increased number can be easily accommodated by simply increasing the number of through holes 41 in the fixed outer cylinder body 40. For example, this does not involve an increase in the number of parts such as valves, and does not result in an increase in the probability of failure. The whole system is compact and easy to carry, and the more samples there are, the lower the cost of the device becomes. [Industrial Applicability]

[0039] In this invention, the inhaled air is sampled in the liquid in a sampling container by connecting a tube that sequentially sends the air to an impinger as a single rotating inner cylinder rotates. Therefore, the substances sampled are not limited to chemical substances that cause air pollution, and it can also be used as a sampling device for pollen, viruses, bacteria, etc. floating in the air. [Explanation of symbols]

[0040] 1 Case 11 Partition 11a Pipe hole 12 Container support part 12a Container support plate 12b Container insertion hole 12c Pipe hole 13 Bottom plate 14 Base plate 15 Exhaust pipe hole 2 Impinger 21 Collection container 22 2-hole plug 22a Air pipe hole 22b Intake pipe hole 23 Air pipe 23a Tip opening 23b Connection port 24 Detachable joint 25 Intake pipe 25a Tip opening 26 Detachable joint 27 Collector intake pipe 28 Air Intake 3. Connection switching mechanism 31 Exhaust pipe 31a Connection port 31b Exhaust port 32 Rotating joint 33 Air Pump 40 Fixed outer cylinder 40a Inner wall surface 40b Outer wall surface 40c Upper end surface 41 Through hole 50 Rotating inner cylinder 50a Outer wall 50b Inner wall surface 51 Through hole 52 Disc Gear 52a Tooth 52b Through hole 52c Placement surface 53 Transmission Gear 54 Motor 55 O-ring 56 Rotating joint 6. Control Unit 61 Electronic components for rotation control A Collection liquid X Cylinder Centerline

Claims

1. a) two or more impingers, one of which is immersed in the sampling liquid in a sampling container and the other of which faces the upper space and which collect pollutants in the air via an intake pipe connected to a collective intake pipe at its end; b) a suction-type air pump equipped with one exhaust pipe for intake or supply of air; c) a connection switching mechanism which maintains the connection between one exhaust pipe on the air pump side and the air supply pipe of two or more impingers for a certain period of time, and then switches the connection between one exhaust pipe and the air supply pipe of another impinger simultaneously with the start of another sampling, and repeats this process for each sampling; and d) a control unit which controls the timing of switching the connection between the impinger side and the air pump side. The connection switching mechanism includes: a cylindrical fixed outer cylinder fixed to a housing, and a cylindrical rotating inner cylinder having an outer diameter substantially equal to that of the fixed outer cylinder, the inner circumferential surface of which is slidable against the outer circumferential surface of the fixed outer cylinder, being rotatably fitted into the fixed outer cylinder; The fixed outer cylinder has a wall on which through holes are formed at regular intervals on the same circumference, the through holes being connected to the air supply pipes of the sampling containers. A through hole connected to an exhaust pipe on the air pump side is drilled in a cylindrical wall of the rotating inner cylinder fitted to the fixed outer cylinder at a position that allows communication with each air supply pipe on the sampling container side by rotation of the rotating inner cylinder, The exhaust pipe is provided to extend upward from a cylinder center position of the connection switching mechanism, A sampling device for air pollutants comprising:

2. 2. The sampling device for air pollutants according to claim 1, characterized in that a disk gear having a common center of rotation with the rotating inner cylinder is fixed to the upper end of the rotating inner cylinder, and the rotating inner cylinder can be rotated by rotating the disk gear with a motor.

3. 3. The sampling device for air pollutants according to claim 2, wherein the exhaust pipe on the air pump side passes through the center of the disk gear and is made of a flexible material that can be twisted.

4. 4. A sampling device for air pollutants as described in claim 2 or 3, characterized in that the exhaust pipe on the air pump side is divided into upper and lower parts at the center of the disc gear, and a rotating connection part that connects the upper side to the lower side so that it can rotate freely is provided at the center of the disc gear.

5. 5. A sampling device for air pollutants as described in any one of claims 1 to 4, characterized in that an O-ring is attached to the opening on the outer circumferential side of the through hole of the rotating inner cylinder to prevent air flow between the inside and outside of the through hole.

Images