Particulate sampling apparatus and particulate sampling method

Abstract

A fine particle sampling device (10) comprising: a cylindrical first electrode (22) having a first opening located at a first end in the cylindrical axial direction of a cylinder and a second opening located at a second end in the axial direction of the cylinder; a second electrode (24) that extends in the axial direction and that is disposed in the first electrode apart from the inner surface of the first electrode; a third electrode (25) that extends in the axial direction, that is disposed in the first electrode apart from the inner surface, that is thicker than the second electrode, and that is located at a position, in the axial direction, different from the position of the second electrode; a supply part (28) that supplies a liquid to the first electrode so as to cause the liquid to be stored in a portion of the inner surface, in a direction around the axis, of the first electrode; a voltage applying part (26) that applies a first voltage between the first electrode and the second electrode and a second voltage between the first electrode and the third electrode; a drive part (32) that rotates the first electrode about a rotation axial line extending in the axial direction and passing through the first electrode; and a collection part (30) that collects the stored liquid.

Description

Technical Field

[0001] The present disclosure relates to a particulate sampling device and a particulate sampling method for sampling particulate matter.

Background Art

[0002] Conventionally, devices and methods for sampling particulate matter in a gas using devices that utilize the inertia and centrifugal force of particulate matter are known (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). Patent Document 1 discloses a method of capturing microorganisms floating in air on a membrane filter by sucking air through the membrane filter. Patent Document 2 discloses an airborne bacteria sampler that attaches and collects airborne bacteria in a culture medium by causing the air inhaled from a suction unit to collide with the culture medium. Patent Document 3 discloses a device that separates and collects a collection target from air by the centrifugal force generated by the swirling of the sucked air.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0004] However, with the conventional configuration described above, fine particles such as aerosols separated from the aspirated air often accumulate in a dry state, requiring further steps for analysis, such as extraction into a solution. If the sampled fine particles are biological, they cannot be collected while maintaining their activity. Even with solutions aimed at recovering the particles into a solution to address these issues, obtaining high concentrations requires a large amount of solution, which takes a lot of time, and the suction process generates significant pressure loss and noise. In addition, the collection performance is largely dependent on factors such as the shape and size of the device, the suction speed, and the size of the target aerosol, resulting in challenges in efficient collection.

[0005] When using electrostatic sampling, it is usually possible to efficiently sample fine particles by charging a larger number of target particles through discharge. However, there is a problem in that active substances such as ozone are generated during this discharge. These active substances can oxidize the target particles, potentially adversely affecting the inspection of the particles after sampling.

[0006] This disclosure has been made in view of the above-mentioned conventional problems, and provides a particulate sampling device and a particulate sampling method that can efficiently sample particulate matter while suppressing the generation of active substances.

[0007] A particulate sampling apparatus according to one aspect of the present disclosure includes a cylindrical first electrode having a first opening located at a first end in the axial direction of the cylinder and a second opening located at a second end in the axial direction of the cylinder, a second electrode extending in the axial direction and disposed within the first electrode at a distance from the inner surface of the first electrode, a third electrode extending in the axial direction and disposed within the first electrode at a distance from the inner surface of the first electrode, and the third electrode being thicker than the second electrode ,beforeThe device comprises: a supply unit that supplies liquid into the first electrode and stores the liquid in a portion of the inner surface in the direction of the axis of the first electrode; a voltage application unit that applies a first voltage between the first electrode and the second electrode, and a second voltage between the first electrode and the third electrode; a drive unit that rotates the first electrode around a rotation axis that extends in the axial direction and passes through the first electrode; and a recovery unit that recovers the stored liquid. The third electrode is thicker than the second electrode, and the positions of the third electrode and the second electrode are different in the axial direction. .

[0008] A particulate sampling method according to one aspect of the present disclosure is a particulate sampling method for a particulate sampling device, the particulate sampling device comprising: a first electrode which is cylindrical and has a first opening located at a first end in the axial direction of the cylinder and a second opening located at a second end in the axial direction of the cylinder; a second electrode which extends in the axial direction and is disposed within the first electrode at a distance from the inner surface of the first electrode; and a third electrode which extends in the axial direction and is disposed within the first electrode at a distance from the inner surface of the first electrode, wherein the third electrode is thicker than the second electrode, and the positions of the third electrode and the second electrode are different in the axial direction, the particulate sampling method comprising: supplying liquid into the first electrode, storing the liquid in a portion of the inner surface of the first electrode in a direction about the axial direction of the first electrode; applying a first voltage between the first electrode and the second electrode and a second voltage between the first electrode and the third electrode; rotating the first electrode about a rotation axis which extends in the axial direction and passes through the first electrode, and recovering the stored liquid.

[0009] A particulate sampling apparatus and a particulate sampling method according to one aspect of this disclosure can efficiently sample particulate matter while suppressing the generation of active substances. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view showing the external appearance of a particulate sampling apparatus according to the first embodiment. [Figure 2] Figure 2 is a side view showing the external appearance of the fine particle sampling device shown in Figure 1. [Figure 3] Figure 3 is a cross-sectional view taken along line III-III in Figure 1. [Figure 4] Figure 4 is an end view of line IV-IV in Figure 1. [Figure 5] Figure 5 is a block diagram showing the configuration of the fine particle sampling apparatus shown in Figure 1. [Figure 6] Figure 6 is a flowchart showing an example of the operation of the particulate sampling device shown in Figure 1. [Figure 7] Figure 7 is a cross-sectional view taken along line III-III in Figure 1, and is an explanatory diagram illustrating an example of the operation performed by the fine particle sampling device in Figure 1. [Figure 8] Figure 8 shows the experimental results of an experiment conducted to confirm the amount of ozone generated and the dust collection efficiency with and without a covering material. [Figure 9] Figure 9 is a cross-sectional view of a particulate sampling apparatus according to the second embodiment. [Figure 10] Figure 10 is a cross-sectional view of a particulate sampling apparatus according to the third embodiment. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described below with reference to the drawings.

[0012] However, the particulate sampling apparatus and particulate sampling method relating to this disclosure are not intended to be limited to the embodiments described below and / or the configurations shown in the drawings, but also include equivalent configurations.

[0013] The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit the scope of the claims. The figures are not necessarily strictly illustrative. In the figures, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0014] In the following, terms indicating relationships between elements such as parallel and perpendicular, terms indicating the shapes of elements such as cylindrical shape, and numerical ranges do not represent strict meanings, but rather mean substantially equivalent ranges, including differences of about several percent, for example.

[0015] In each of the following figures, the X-axis and the Y-axis are axes orthogonal to each other on a horizontal plane. The Z-axis is an axis perpendicular to the horizontal plane. In the Z-axis, the positive direction represents vertically upward, and the negative direction represents vertically downward.

[0016] (First Embodiment) FIG. 1 is a perspective view showing the appearance of the fine particle sampling device 10 according to the first embodiment. FIG. 2 is a side view showing the appearance of the fine particle sampling device 10 of FIG. 1. FIG. 3 is an internal view of the fine particle sampling device 10 of FIG. 1 and is a sectional view taken along line III-III of FIG. 1. FIG. 4 is an end view taken along line IV-IV of FIG. 1. In FIG. 1, illustration of the wind speed sensor 34 and the like is omitted. Referring to FIGS. 1 to 4, the fine particle sampling device 10 according to the first embodiment will be described.

[0017] As shown in FIGS. 1 to 4, the fine particle sampling device 10 is a device for sampling fine particles into a liquid. Specifically, the fine particle sampling device 10 is a device for sampling fine particles into a liquid by collecting fine particles in the gas into a liquid 68 (described later). Examples of fine particles include fungi, bacteria, viruses, and aerosols. The fine particle sampling device 10 includes a duct 12, a first bearing seal 14, a second bearing seal 16, a first flange member 18, a second flange member 20, a first electrode 22, a second electrode 24, a third electrode 25, a voltage application unit 26, a supply unit 28, a recovery unit 30, a drive unit 32, a wind speed sensor 34, an in-air concentration sensor 36, a in-liquid concentration sensor 38, and a ammeter 40.

[0018] The particulate sampling device 10 is constructed by surrounding a rotating first electrode 22 and a second electrode 24 and a third electrode 25 located at the center of the first electrode 22 with a duct 12, a first flange member 18, and a second flange member 20. A gas such as air is passed through the inside of the particulate sampling device 10 in a direction that allows the particulate sampling device 10 to pass through (as indicated by arrow A in Figure 2). For example, air may be drawn directly into the particulate sampling device 10 using a pump (not shown) and the gas may be passed through the particulate sampling device 10. For example, the particulate sampling device 10 may be installed in a device that has a flow of gas such as air, such as an air conditioner, air purifier, or ventilation opening, and air may be drawn into the particulate sampling device 10 for processing. In this way, by attaching the particulate sampling device 10 to a device that generates a gas flow, it is not necessary to incorporate a pump or the like to generate the gas flow into the particulate sampling device 10, and a compact, quiet, and low-pressure-loss device can be easily realized. This allows the particulate sampling device 10 to be installed and incorporated into a variety of locations, with relatively few restrictions on the location. The components of the particulate sampling device 10 will be described below.

[0019] The duct 12 is cylindrical and rotatably supports the first electrode 22 inside the duct 12. The duct 12 has a main body 42, a first support portion 44, and a second support portion 46. The main body 42, the first support portion 44, and the second support portion 46 are insulating.

[0020] The main body 42 is cylindrical, with one end in the axial direction having an opening, and the other end in the axial direction having an opening.

[0021] The first support portion 44 protrudes radially outward from one end of the main body 42 in the axial direction and is integrally formed with the main body 42. The first support portion 44 is recessed radially outward from the main body 42 and is substantially U-shaped (see Figure 3). When viewed from the axial direction of the main body 42, the first support portion 44 is annular. A first bearing seal 14 is positioned inside the first support portion 44. The first bearing seal 14 seals the space between the first support portion 44 and the first outer flange portion 58 (described later) to prevent gas leakage between the first support portion 44 and the first outer flange portion 58. The first support portion 44 rotatably supports the first electrode 22 via the first bearing seal 14.

[0022] The second support portion 46 protrudes radially outward from the other end of the main body 42 in the axial direction and is integrally formed with the main body 42. The second support portion 46 is recessed radially outward from the main body 42 and is substantially U-shaped (see Figure 3). When viewed from the axial direction of the main body 42, the second support portion 46 is annular. A second bearing seal 16 is positioned inside the second support portion 46. The second bearing seal 16 seals the space between the second support portion 46 and the second outer flange portion 60 (described later) to prevent gas leakage between the second support portion 46 and the second outer flange portion 60. The second support portion 46 rotatably supports the first electrode 22 via the second bearing seal 16.

[0023] The first flange member 18 is cylindrical and connected to the duct 12. The first flange member 18 has a main body 48 and a flange 50.

[0024] The main body 48 is cylindrical, with an opening at one end in the axial direction and an opening at the other end in the axial direction. The flange 50 protrudes radially outward from one end in the axial direction of the main body 48 and is integrally formed with the main body 48. When viewed from the axial direction of the main body 48, the flange 50 is annular. The other end in the axial direction of the main body 48 is connected to one end in the axial direction of the duct 12.

[0025] The second flange member 20 is cylindrical and connected to the duct 12. The second flange member 20 has a main body 52 and a flange 54.

[0026] The main body 52 is cylindrical, with an opening at one end in the axial direction and an opening at the other end in the axial direction. The axial end of the main body 52 is connected to the other end in the axial direction of the duct 12. The flange 54 protrudes radially outward from the other end in the axial direction of the main body 52 and is integrally formed with the main body 52. ​​When viewed from the axial direction of the main body 52, the flange 54 is annular.

[0027] The first electrode 22 is cylindrical, with an opening at one end in the axial direction and an opening at the other end in the axial direction. The first electrode 22 is connected to the ground via a second electric wire 76 (described later), etc. The first electrode 22 has a body 56, a first outer flange 58, a second outer flange 60, a first inner flange 62, and a second inner flange 64. For example, the body 56, the first outer flange 58, the second outer flange 60, the first inner flange 62, and the second inner flange 64 are made of stainless steel such as SUS.

[0028] The main body 56 is cylindrical, with an opening at one end in the axial direction and an opening at the other end in the axial direction. The axial direction of the main body 56 is the direction in which the axis B of the main body 56 extends (X-axis direction). The main body 56 has external teeth (not shown) on its outer circumferential surface that mesh with the external teeth (not shown) of the gear 86 (described later). The inner surface 66 of the main body 56 is subjected to a hydrophilic treatment. The hydrophilic treatment is a process that processes the inner surface 66 into a microscopic uneven shape. For example, the hydrophilic treatment is performed by plasma treatment. For example, the hydrophilic treatment is performed by alkaline treatment using potassium hydroxide (KOH). The inner surface 66 of the main body 56 is fitted with an adhesion suppression member to suppress the adhesion of fine particles. For example, the adhesion suppression member is a blocking agent such as skim milk, BSA (Bovine Serum Albumin), and PEG (Polyethylene Glycol). The axis of the main body 56 and the axis of the first electrode 22 coincide.

[0029] The first outer flange portion 58 protrudes radially outward from one end of the main body 56 in the axial direction and is integrally formed with the main body 56. The first outer flange portion 58 is annular around the axis B of the main body 56. That is, the first outer flange portion 58 is annular when viewed from the axial direction of the main body 56. The first outer flange portion 58 is located inside the first bearing seal 14.

[0030] The second outer flange portion 60 protrudes radially outward from the other end of the main body 56 in the axial direction and is integrally formed with the main body 56. The second outer flange portion 60 is annular around the axis B of the main body 56. That is, the second outer flange portion 60 is annular when viewed from the axial direction of the main body 56. The second outer flange portion 60 is located inside the second bearing seal 16.

[0031] The first inner flange portion 62 protrudes radially inward from one end of the main body 56 in the axial direction and is integrally formed with the main body 56. The first inner flange portion 62 is annular around the axis B of the main body 56. That is, the first inner flange portion 62 is annular when viewed from the axial direction of the main body 56.

[0032] The second inner flange portion 64 protrudes radially inward from the other end of the main body 56 in the axial direction and is integrally formed with the main body 56. The second inner flange portion 64 is annular around the axis B of the main body 56. That is, the second inner flange portion 64 is annular when viewed from the axial direction of the main body 56.

[0033] The first electrode 22 is installed in a position where the axis B of the main body 56 is parallel to the horizontal direction. The first electrode 22 is supported so as to be rotatable around the axis B of the main body 56 (see arrow C in Figure 4). In other words, the first electrode 22 is supported so as to be able to rotate.

[0034] The first electrode 22 stores liquid 68 on the inner surface 66 of the main body 56. Specifically, the first electrode 22 stores liquid 68 in a portion of the inner surface 66 in the direction around the axis B of the main body 56 (see arrow D in Figure 4). The stored liquid 68 is located below the axis B of the main body 56. The first electrode 22 stores liquid 68 in this portion of the inner surface 66 along the axial direction of the main body 56. The first inner flange 62 holds the liquid 68 stored in a portion of the inner surface 66 of the main body 56 so that it does not spill from one end of the main body 56 in the axial direction. The second inner flange 64 holds the liquid 68 held in a portion of the inner surface 66 of the main body 56 so that it does not spill from the other end of the main body 56 in the axial direction. Thus, the first electrode 22 has a structure that allows liquid 68 to be stored in a part of its inner surface 66, and the liquid 68 is stored in a part of the inner surface 66 of the main body 56 so that the liquid 68 does not flow out to the outside of the main body 56. Within the main body 56, a space 69 is formed above the stored liquid 68, penetrating the main body 56 in the axial direction.

[0035] The second electrode 24 is linear and extends in the axial direction of the body 56 of the first electrode 22. The second electrode 24 is inserted radially into one end of the body 56 of the first electrode 22 in the axial direction and is located inside the body 56. In the axial direction of the body 56, the second electrode 24 protrudes outward from the opposite side of one end of the body 56 to the other end. The second electrode 24 extends from the opposite side of one end of the first electrode 22 to the side of the center G of the first electrode 22 in the axial direction within the first electrode 22. For example, the center G is the midpoint between one end and the other end of the body 56 in the axial direction. The second electrode 24 faces the first inner flange 62 in a direction perpendicular to the axial direction of the body 56 of the first electrode 22.

[0036] The second electrode 24 is positioned at a distance from the inner surface 66 of the body 56 of the first electrode 22, and is located near the center of the first electrode 22. The second electrode 24 is positioned within the space 69. In this embodiment, the second electrode 24 is installed in a position where its axis coincides with the axis B of the body 56 of the first electrode 22. For example, the second electrode 24 is made of tungsten or the like.

[0037] The second electrode 24 is positioned within the first electrode 22, on one end side of the first electrode 22 and on the other end side of the first electrode 22, with respect to the central G in the axial direction of the first electrode 22. In other words, the second electrode 24 is not positioned on the other end side of the central G within the first electrode 22.

[0038] The arrangement of the second electrode 24 may be interpreted as follows: The first electrode 22 has a first opening located at the first end in the axial direction of the first electrode 22, and a second opening located at the second end in the axial direction of the first electrode 22. Within the first electrode 22, the second electrode 24 is (i) positioned between the first opening and the first surface, (ii) not positioned between the first surface and the second opening, and (iii) in direct contact with the third electrode 25 and the first surface. The distance between the first surface and the first opening is smaller than the distance between the first surface and the second opening, and the axial direction of the first surface and the first electrode 22 are perpendicular.

[0039] The third electrode 25 extends in the axial direction of the body 56 of the first electrode 22. The third electrode 25 has a core member 100 and a covering member 102 that covers the core member 100. The core member 100 is linear and extends in the axial direction of the body 56 of the first electrode 22. The covering member 102 is cylindrical and extends in the axial direction of the body 56 of the first electrode 22. The core member 100 and the covering member 102 are conductive.

[0040] A core member 100 is provided inside the covering member 102, and the covering member 102 covers the outside of the core member 100. For example, the covering member 102 may cover the core member 100 in a state of close contact with it, or it may cover the core member 100 with a small gap between it and the core member 100. The covering member 102 only needs to cover the core member 100 with at least a part of the covering member 102 in contact with the core member 100 so that it is electrically connected to the core member 100.

[0041] The third electrode 25 is positioned within the first electrode 22, spaced apart from the inner surface 66 of the body 56 of the first electrode 22. Specifically, the core member 100 and the covering member 102 are positioned spaced apart from the inner surface 66 of the body 56 of the first electrode 22, and are located near the center of the first electrode 22. The core member 100 and the covering member 102 are positioned within the space 69. In this embodiment, the core member 100 is installed in a position where its axis coincides with the axis B of the body 56 of the first electrode 22, and the covering member 102 is installed in a position where its axis coincides with the axis B of the body 56 of the first electrode 22.

[0042] The third electrode 25 is thicker than the second electrode 24. Here, thickness is the dimension in the direction perpendicular to the extension direction. That is, the thickness of the third electrode 25 is the dimension H1 of the third electrode 25 in the direction perpendicular to the axial direction of the body 56 of the first electrode 22, and the thickness of the second electrode 24 is the dimension H2 of the second electrode 24 in the direction perpendicular to the axial direction of the body 56 of the first electrode 22. The dimension H1 of the third electrode 25 in the direction perpendicular to the axial direction of the body 56 of the first electrode 22 is greater than the dimension H2 of the second electrode 24.

[0043] For example, if the outer shape of the third electrode 25 in a cross-section perpendicular to the extending direction is circular, the diameter of that outer shape is defined as the thickness of the third electrode 25. For example, if the outer shape of the third electrode 25 in a cross-section perpendicular to the extending direction is not circular, the dimension of the widest part of that outer shape may be defined as the thickness of the third electrode 25, or the dimension of the narrowest part of that outer shape may be defined as the thickness of the third electrode 25, or the average value of the dimension of the widest part and the dimension of the narrowest part may be defined as the thickness of the third electrode 25. If the thickness of the third electrode 25 differs at each position in the extending direction, the dimension of the widest part may be defined as the thickness of the third electrode 25, or the dimension of the narrowest part may be defined as the thickness of the third electrode 25, or the average value of the dimension of the widest part and the dimension of the narrowest part may be defined as the thickness of the third electrode 25. The same applies to the second electrode 24. If the outer shape of the second electrode 24 in a cross-section perpendicular to the extending direction is circular, the diameter of that outer shape is defined as the thickness of the second electrode 24. For example, if the outer shape of the second electrode 24 in a cross-section perpendicular to the extending direction is not circular, the dimension of the widest part of that outer shape may be defined as the thickness of the second electrode 24, or the dimension of the narrowest part of that outer shape may be defined as the thickness of the second electrode 24, or the average value of the dimension of the widest part and the dimension of the narrowest part may be defined as the thickness of the second electrode 24. If the thickness of the second electrode 24 differs at each position in the extending direction, the dimension of the widest part may be defined as the thickness of the second electrode 24, or the dimension of the narrowest part may be defined as the thickness of the second electrode 24, or the average value of the dimension of the widest part and the dimension of the narrowest part may be defined as the thickness of the second electrode 24.

[0044] In this embodiment, the core member 100 is approximately the same thickness as the second electrode 24, and the covering member 102 covers the core member 100, making the third electrode 25 thicker than the second electrode 24. In other words, in this embodiment, the covering member 102 is a member that makes the third electrode 25 thicker than the second electrode 24.

[0045] For example, the thickness of the second electrode 24 is such that when a voltage is applied between the first electrode 22 and the second electrode 24, a discharge such as corona discharge occurs. Specifically, for example, the thickness of the second electrode 24 is such that when a voltage is applied between the first electrode 22 and the second electrode 24, a discharge such as corona discharge is likely to occur.

[0046] For example, the thickness of the third electrode 25 is such that when a voltage is applied between the first electrode 22 and the third electrode 25, discharges such as corona discharge are less likely to occur. Specifically, for example, the thickness of the third electrode 25 is such that when a voltage is applied between the first electrode 22 and the third electrode 25, discharges such as corona discharge do not occur.

[0047] The third electrode 25 is positioned differently from the second electrode 24 in the axial direction of the body 56 of the first electrode 22. In this embodiment, the third electrode 25 is positioned on the other end side of the first electrode 22 than the second electrode 24 in the axial direction of the body 56 of the first electrode 22. In other words, in this embodiment, the second electrode 24 is positioned on the one end side of the first electrode 22 than the third electrode 25 in the axial direction of the body 56 of the first electrode 22.

[0048] Specifically, the core member 100 and the covering member 102 are positioned differently from the second electrode 24 in the axial direction of the main body 56 of the first electrode 22. When viewed from one end of the main body 56 of the first electrode 22 in the axial direction, the second electrode 24 is located in front of the core member 100 and the covering member 102, while the core member 100 and the covering member 102 are located behind the second electrode 24. Therefore, when gas is introduced into the first electrode 22 from that end, the gas passes between the second electrode 24 and the first electrode 22, then between the covering member 102 and the first electrode 22, and is subsequently released outside the first electrode 22 from the other end of the first electrode 22.

[0049] The third electrode 25 is positioned alongside the second electrode 24 in the axial direction of the body 56 of the first electrode 22. Specifically, the core member 100 and the covering member 102 are positioned alongside the second electrode 24 in the axial direction of the body 56 of the first electrode 22. When viewed from the axial direction of the body 56 of the first electrode 22, the core member 100 and the second electrode 24 overlap, and the core member 100 is aligned with the second electrode 24 in the axial direction of the body 56 of the first electrode 22. When viewed from the axial direction of the body 56 of the first electrode 22, at least a portion of the second electrode 24 is located inward from the outer shape of the covering member 102, and the covering member 102 is aligned with the second electrode 24 in the axial direction of the body 56 of the first electrode 22.

[0050] Within the first electrode 22, the third electrode 25 is longer than the second electrode 24. That is, the length of the third electrode 25 within the first electrode 22 is longer than the length of the second electrode 24 within the first electrode 22. Here, length is the dimension in the extending direction. That is, the length of the third electrode 25 within the first electrode 22 is the dimension I1 of the portion of the third electrode 25 located within the first electrode 22 in the axial direction of the body 56 of the first electrode 22. The length of the second electrode 24 within the first electrode 22 is the dimension I2 of the portion of the second electrode 24 located within the first electrode 22 in the axial direction of the body 56 of the first electrode 22. The dimension I1 of the portion of the third electrode 25 located within the first electrode 22 is greater than the dimension I2 of the portion of the second electrode 24 located within the first electrode 22. Specifically, the dimension I1 of the core member 100 located within the first electrode 22 is larger than the dimension I2 of the second electrode 24 located within the first electrode 22. The dimension I1 of the covering member 102 located within the first electrode 22 is larger than the dimension I2 of the second electrode 24 located within the first electrode 22.

[0051] The third electrode 25 extends from one end of the first electrode 22 beyond the center G of the first electrode 22 to the opposite side of the other end of the first electrode 22. Specifically, the core member 100 and the covering member 102 extend from one end of the body 56 of the first electrode 22 beyond the center G of the first electrode 22 to the opposite side of the other end of the body 56 of the first electrode 22. In other words, the core member 100 and the covering member 102 are inserted radially inward from the other end of the body 56 of the first electrode 22 in the axial direction, and protrude outward from the other end of the body 56 to the opposite side of the other end. The covering member 102 faces the second inner flange 64 in a direction perpendicular to the axial direction of the body 56 of the first electrode 22.

[0052] The arrangement of the third electrode 25 may be interpreted as follows: The first electrode 22 has a first opening located at the first end in the axial direction of the first electrode 22, and a second opening located at the second end in the axial direction of the first electrode 22. Within the first electrode 22, the third electrode 25 is (i) not positioned between the first opening and the first surface, (ii) positioned between the first surface and the second opening, and (iii) in direct contact with the second electrode 24 and the first surface. The distance between the first surface and the first opening is smaller than the distance between the first surface and the second opening, and the axial direction of the first surface and the first electrode 22 are perpendicular.

[0053] At least a portion of the third electrode 25 is integrally formed with the second electrode 24. Specifically, the core member 100 is integrally formed with the second electrode 24 such that the core member 100 is continuous with the second electrode 24 in the axial direction of the main body 56 of the first electrode 22. On the other hand, the covering member 102 is separate from the core member 100 and the second electrode 24 and is not integrally formed with the second electrode 24.

[0054] In this embodiment, the second electrode 24 and the core member 100 are formed from a single conductive member having electrical conductivity. Of the conductive member, the portion covered by the covering member 102 is the core member 100, and the portion that is not covered by the covering member 102 and is exposed is the second electrode 24. For example, the core member 100 is integrally formed with the second electrode 24 from tungsten or the like, and the covering member 102 is formed from stainless steel such as SUS.

[0055] For example, the second electrode 24 and the third electrode 25 may be implemented by a structure in which a portion of a linear electrode is further covered with a conductive material. In this case, the covered portion of the electrode may be located on the rear side (back side) along the direction of fluid flow relative to the uncovered exposed portion of the electrode. As a result, the local electric field formed by the voltage difference becomes larger between the front portion of the electrode and the first inner flange portion 62, etc., and a discharge occurs between these two points. This discharge charges the target particles, which are the fine particles to be sampled, and at the same time, the generated substances such as ozone can oxidize the target particles. On the other hand, in the rear portion of the covered electrode, the concentration of the electric field is smaller, so no discharge occurs. However, because the distance between this portion and the first electrode 22 becomes smaller, the electric field between these electrodes becomes larger, and the target particles passing between these electrodes are collected with greater force. This makes it possible to improve the amount of dust collected while suppressing the generation of active substances such as ozone by not charging the particles more than necessary. The position and length of the covering can be adjusted by sliding the covering member 102, etc., to suit the dust collection environment and / or the target particles. If there is no need to change the position of the covering, the structure of the second electrode 24 and the third electrode 25 may be originally narrower at the front and wider at the rear (see Figure 10).

[0056] The voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24, and between the first electrode 22 and the third electrode 25. Specifically, the voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24 to form an electric field between them. The voltage application unit 26 also applies a voltage between the first electrode 22 and the third electrode 25 to form an electric field between them. The voltage application unit 26 includes a first support 70, a second support 72, a first wire 74, and a second wire 76.

[0057] The first support 70 is fixed to the first flange member 18 and is located inside the first flange member 18. The first support 70 is connected to one axial end of the second electrode 24 and supports the second electrode 24. The second support 72 is fixed to the second flange member 20 and is located inside the second flange member 20. The second support 72 is connected to the other axial end of the third electrode 25 and supports the third electrode 25. The first support 70 and the second support 72 are conductive and are electrically connected to the second electrode 24 and the third electrode 25. The first wire 74 is electrically connected to the second electrode 24 and the third electrode 25 via the second support 72. The second wire 76 is electrically connected to the first electrode 22 via a gear 86 or the like.

[0058] The voltage application unit 26 can pass electricity of any magnitude and waveform through the first wire 74 and the second wire 76 to the first electrode 22 and the second electrode 24 and third electrode 25, which are installed near the center of the first electrode 22. This allows the particulate sampling device 10 to electrostatically collect particulate matter. The structure of the second electrode 24 and the core member 100 does not have to be linear; they can be plate-shaped, needle-shaped, etc., and there are no limitations on their structure or installation location, as long as they can form an uneven electric field. For example, the voltage application unit 26 can be implemented by a power supply circuit including a converter. For example, the voltage application unit 26 applies a DC voltage of 6 [kV].

[0059] For example, the voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24, and between the first electrode 22 and the third electrode 25, such that the second electrode 24 side is at a higher potential than the first electrode 22 side, and the third electrode 25 side is at a higher potential than the first electrode 22 side. As a result, an electric field is generated in space 69 from the second electrode 24 toward the first electrode 22, and an electric field is generated from the third electrode 25 toward the first electrode 22 (see arrow E in Figure 3 and arrow E in Figure 4).

[0060] The supply unit 28 supplies liquid 68 into the first electrode 22, causing the liquid 68 to be stored in a portion of the inner surface 66 of the first electrode 22 in the direction of the axis B. In other words, the supply unit 28 supplies liquid 68 into the first electrode 22 in order to store the liquid 68 in a portion of the inner surface 66 of the first electrode 22 in the direction of the axis B. In this way, the liquid 68 supplied by the supply unit 28 is stored on the inner surface 66 of the body 56 of the first electrode 22. The supply unit 28 has a tank 78 and an injection unit 80.

[0061] Tank 78 holds liquid 68 for supply into the first electrode 22. The liquid 68 held in tank 78 is discharged from injection section 80 by a pump (not shown) or the like and supplied into the main body 56 of the first electrode 22. In this way, a tank 78 is installed to store liquid 68 such as a collection solution for influenza virus sensing in advance, and the liquid 68 is supplied to the inside of the first electrode 22 through injection section 80.

[0062] In this embodiment, the supply unit 28 supplies a liquid for the analysis of particulate matter as liquid 68. For example, the liquid for the analysis of particulate matter means a liquid used for analysis, a liquid that maintains the activity of the target substance contained in the particulate matter for analysis, a liquid that labels the target substance contained in the particulate matter for analysis, a liquid that protects the target substance contained in the particulate matter for analysis, or any combination thereof. Liquid 68 may also be a liquid intended for dissolution and preservation. Examples of liquids intended for dissolution and preservation include physiological saline, PBS buffer, EDTA buffer, and bicarbonate buffer. Liquid 68 may be a liquid containing a substance that specifically binds to viruses and emits magnetism and / or fluorescence. Note that liquid 68 does not have to be a liquid for the analysis of particulate matter; for example, it may be pure water.

[0063] Furthermore, the target substance is not limited to the influenza virus. For example, the target substance may be another virus, or a living organism other than a virus (for example, bacteria). The target substance does not have to be a living organism; it may be an environmental pollutant or an allergen, etc.

[0064] The recovery unit 30 recovers the liquid 68 stored in a portion of the inner surface 66 of the first electrode 22 in the direction of the axis B. The recovery unit 30 has a tank 82 and an extraction unit 84. The liquid 68 stored in a portion of the inner surface 66 of the first electrode 22 in the direction of the axis B is sucked from the extraction unit 84 by a pump (not shown) or the like, held in the tank 82, and recovered. In this way, the liquid 68, such as the collection liquid in which fine particles have accumulated, is sucked through the extraction unit 84 and held in the tank 82.

[0065] The drive unit 32 rotates the first electrode 22 around a rotation axis that extends in the axial direction of the body 56 of the first electrode 22 and passes through the first electrode 22. In this embodiment, the rotation axis coincides with the axis B of the body 56. That is, in this embodiment, the drive unit 32 rotates the first electrode 22 around the axis B of the body 56 of the first electrode 22. The drive unit 32 has a gear 86 and a motor 88 for rotating the gear 86. The gear 86 has external teeth (not shown) that mesh with the external teeth (not shown) of the first electrode 22. As the motor 88 rotates the gear 86 (see arrow F in Figure 4), the first electrode 22 rotates around the axis B of the body 56 (see arrow C in Figure 4). In this way, the first electrode 22 is rotated by the gear 86 driven by the motor 88.

[0066] The wind speed sensor 34 is installed on the inner surface of the main body 48 of the first flange member 18 and measures the wind speed of the gas that is (intended to) pass through the first electrode 22. The gas outside the particulate sampling device 10 passes through the inside of the first flange member 18, through the inside of the main body 56 of the first electrode 22, and through the inside of the second flange member 20 and is released to the outside of the particulate sampling device 10 (see arrow A in Figure 2 and arrow A in Figure 3). In this way, the wind speed sensor 34 measures the wind speed of the gas passing through the first electrode 22 (i.e., the gas before it passes through the first electrode 22).

[0067] Furthermore, the gas outside the particulate sampling device 10 may pass through the inside of the second flange member 20, through the inside of the main body 56 of the first electrode 22, and be released to the outside of the particulate sampling device 10 from the first flange member 18. In this case, the wind speed sensor 34 can measure the wind speed of the gas passing inside the first electrode 22 (i.e., the gas after passing inside the first electrode 22).

[0068] The control unit 90 receives the wind speed measured by the wind speed sensor 34, and the control unit 90 may determine that the wind speed is the wind speed of the gas inside the first electrode 22.

[0069] The air concentration sensor 36 is positioned on the inner surface of the main body 48 of the first flange member 18 and measures the concentration of particulate matter in the gas before or after it passes through the first electrode 22, as described above. For example, the air concentration sensor 36 is an optical sensor. The control unit 90 receives the concentration of particulate matter measured by the air concentration sensor 36 and may determine that this concentration is the concentration of particulate matter in the gas within the first electrode 22.

[0070] The liquid concentration sensor 38 is positioned in a liquid 68 stored in a portion of the inner surface 66 of the first electrode 22 in the direction of the axis B, and measures the concentration of fine particles in the liquid 68. For example, the liquid concentration sensor 38 is an optical sensor.

[0071] The ammeter 40 is connected to the second electric wire 76 and measures the first current value of the first current flowing between the first electrode 22 and the second electrode 24, the second current value of the second current flowing between the first electrode 22 and the third electrode 25, or the third current value based on the first and second currents. The ammeter 40 only needs to be installed at a location where it can measure the first current value of the first current, the second current value of the second current, or the third current value based on the first and second currents.

[0072] Figure 5 is a block diagram showing the functional configuration of the particulate sampling device 10. The functional configuration of the particulate sampling device 10 will be explained with reference to Figure 5.

[0073] As shown in Figure 5, the particulate sampling device 10 further includes a control unit 90.

[0074] The control unit 90 is electrically connected to the wind speed sensor 34, the air concentration sensor 36, the liquid concentration sensor 38, the ammeter 40, the voltage application unit 26, the supply unit 28, the recovery unit 30, and the drive unit 32. Based on the measurement results of the wind speed sensor 34, the air concentration sensor 36, the liquid concentration sensor 38, and the ammeter 40, the control unit 90 controls the voltage application unit 26, the supply unit 28, the recovery unit 30, and the drive unit 32. For example, the control unit 90 is implemented by a microcomputer, but it may also be implemented by a processor or dedicated circuitry.

[0075] The control unit 90 calculates the flow rate of the gas passing inside the body 56 of the first electrode 22 based on the measurement results of the wind speed sensor 34, and outputs the said flow rate. For example, the control unit 90 calculates the flow rate using the wind speed of the gas passing inside the body 56 of the first electrode 22 and the cross-sectional area of ​​the flow path through which the gas passes. The control unit 90 outputs the calculated flow rate to another device (not shown). This allows for the analysis of fine particles and other similar operations using the flow rate calculated by the control unit 90.

[0076] The control unit 90 controls the voltage application unit 26 and the drive unit 32 based on the measurement results from the air concentration sensor 36. Specifically, if the concentration of particulate matter in the gas is higher than a predetermined concentration, the control unit 90 causes the voltage application unit 26 to apply a voltage between the first electrode 22 and the second electrode 24, and to apply a voltage between the first electrode 22 and the third electrode 25. If the concentration of particulate matter in the gas is higher than a predetermined concentration, the control unit 90 causes the drive unit 32 to rotate the first electrode 22.

[0077] The control unit 90 controls the voltage application unit 26 based on the measurement results of the liquid concentration sensor 38. Specifically, if the concentration of fine particles in the stored liquid 68 is higher than a predetermined concentration, the control unit 90 stops the application of voltage between the first electrode 22 and the second electrode 24, and stops the application of voltage between the first electrode 22 and the third electrode 25. For example, if the concentration of fine particles in the stored liquid 68 is higher than a predetermined concentration, the control unit 90 may also stop the rotation of the first electrode 22 by the drive unit 32. For example, if the concentration of fine particles in the stored liquid 68 is higher than a predetermined concentration, the control unit 90 may also cause the recovery unit 30 to recover the stored liquid 68.

[0078] The control unit 90 controls the supply unit 28 based on the measurement results of the ammeter 40. For example, when the amount of stored liquid 68 decreases, the resistance between the first electrode 22 and the second electrode 24, and the resistance between the first electrode 22 and the third electrode 25 decrease. As a result, the current values ​​flowing between the first electrode 22 and the second electrode 24, and the current values ​​flowing between the first electrode 22 and the third electrode 25 increase. Therefore, if the current value measured by the ammeter 40 is greater than a predetermined value, the control unit 90 causes the supply unit 28 to supply liquid 68 into the body 56 of the first electrode 22, thereby replenishing the liquid 68 in the body 56 of the first electrode 22. For example, the control unit 90 causes the supply unit 28 to replenish the liquid 68 in the main body 56 of the first electrode 22 if the first current value of the first current flowing between the first electrode 22 and the second electrode 24 is greater than a predetermined value, if the second current value of the second current flowing between the first electrode 22 and the third electrode 25 is greater than a predetermined value, or if the third current value based on the first and second currents is greater than a predetermined value.

[0079] Next, the operation of the particulate sampling device 10 configured as described above will be explained. Figure 6 is a flowchart showing an example of the operation of the particulate sampling device 10. Figure 7 is an explanatory diagram for illustrating an example of the operation of the particulate sampling device 10, and shows the movement of the virus inside the particulate sampling device 10 until the virus is actually recovered. Referring to Figures 6 and 7, an example of the operation of the particulate sampling device 10 in this embodiment will be explained, including the flow of influenza virus 1 collection, liquid recovery of influenza virus 1, and recovery of liquid 68. Here, liquid collection by the particulate sampling device 10 is performed with the aim of recovering influenza virus 1, which is thought to be transmitted through airborne transmission, as a liquid sample that can be analyzed by sensors, etc.

[0080] As shown in Figure 6, first, the supply unit 28 supplies liquid 68 into the first electrode 22, causing the liquid 68 to be stored in a portion of the inner surface 66 of the first electrode 22 in the direction of the axis B (supply step) (step S1). For example, the control unit 90 receives instructions from the user via an operation button (not shown), and the control unit 90 causes the supply unit 28 to supply liquid 68 into the main body 56 of the first electrode 22. Alternatively, for example, the control unit 90 may cause the supply unit 28 to supply liquid 68 into the main body 56 of the first electrode 22 based on the measurement results of the air concentration sensor 36.

[0081] As shown in Figure 7, liquid 68 is supplied into the body 56 of the first electrode 22, and the liquid 68 is stored in a portion of the inner surface 66 of the body 56 of the first electrode 22 in the direction of the axis B.

[0082] Returning to Figure 6, the voltage application unit 26 then applies a voltage between the first electrode 22 and the second electrode 24 and between the first electrode 22 and the third electrode 25 (voltage application step) (step S2). For example, based on the measurement results of the air concentration sensor 36, the control unit 90 causes the voltage application unit 26 to apply a voltage between the first electrode 22 and the second electrode 24, and between the first electrode 22 and the third electrode 25. Alternatively, the control unit 90 may receive instructions from the user via an operation button (not shown), and the control unit 90 may cause the voltage application unit 26 to apply a voltage between the first electrode 22 and the second electrode 24, and between the first electrode 22 and the third electrode 25.

[0083] As shown in Figure 7, influenza viruses 1 in a gas introduced into the particulate sampling device 10 by an arbitrary airflow (see arrow A in Figure 7) are first charged either positively or negatively by ions 2 released by the discharge of the second electrode 24 to which a high voltage is applied. Here, we will describe the case in which the influenza viruses 1 are positively charged. The charged influenza viruses 1 move as shown in trajectory 3 by the electric field formed between the second electrode 24 and the first electrode 22 and the electric field formed between the third electrode 25 and the first electrode 22 (see arrow E in Figure 7), and are collected on the inner surface 66 of the first electrode 22. In this way, the influenza viruses 1 adhere to the inner surface 66 of the first electrode 22 and are collected on the inner surface 66.

[0084] Returning to Figure 6, the next step is for the drive unit 32 to rotate the first electrode 22 around the axis B (drive step) (step S3). For example, based on the measurement results of the air concentration sensor 36, the control unit 90 instructs the drive unit 32 to rotate the first electrode 22. Alternatively, the control unit 90 may receive instructions from the user via an operation button (not shown) and instruct the drive unit 32 to rotate the first electrode 22.

[0085] As shown in Figure 7, the first electrode 22 rotates around the axis B with liquid 68 stored in a portion of the inner surface 66 of the body 56 of the first electrode 22 in the direction of the axis B. In other words, the first electrode 22 rotates around the axis B with the liquid 68 stored below the axis B so that the liquid 68 does not flow out of the body 56. As a result, the portion of the inner surface 66 of the first electrode 22 located vertically below the axis B comes into contact with the stored liquid 68 in sequence.

[0086] The influenza virus 1 collected on the inner surface 66 is recovered at any time using the liquid 68 stored inside the main body 56 of the first electrode 22. Specifically, the influenza virus 1 adhering to the inner surface 66 of the main body 56 of the first electrode 22 is recovered into the liquid 68 by coming into contact with the stored liquid 68. The movement (rotation) of the first electrode 22, which is rotated by the motor 88 and gear 86, makes it possible to wash the entire surface of the inner surface 66 of the first electrode 22 with the accumulated (stored) liquid 68.

[0087] Alternatively, before applying a voltage between the first electrode 22 and the second electrode 24, and between the first electrode 22 and the third electrode 25, the first electrode 22 may be rotated around axis B, and then the voltage may be applied between the first electrode 22 and the second electrode 24, and between the first electrode 22 and the third electrode 25, while the first electrode 22 is rotated around axis B.

[0088] Returning to Figure 6, finally, the recovery unit 30 recovers the stored liquid 68 (recovery step) (step S4). For example, after rotating the first electrode 22 for a certain period of time, the liquid 68 can be recovered in the recovery unit 30 (tank 82) through the extraction unit 84 at any timing. This makes it possible to obtain a liquid sample (liquid 68) containing influenza virus 1 separated from the gas. Alternatively, for example, based on the measurement result of the liquid concentration sensor 38, the control unit 90 may instruct the recovery unit 30 to recover the liquid 68 stored in the main body 56 of the first electrode 22. For example, the control unit 90 may receive instructions from the user via an operation button (not shown), and the control unit 90 may instruct the recovery unit 30 to recover the liquid 68 stored in the main body 56 of the first electrode 22.

[0089] When sampling fine particles, using the wind speed sensor 34, air concentration sensor 36, and liquid concentration sensor 38 allows for more appropriate and efficient sampling. By combining wind speed information from the wind speed sensor 34, area information at the measurement location of the wind speed sensor 34, and operating time information, it is possible to obtain information on how much air volume has been processed. The air concentration sensor 36 provides information on the concentration of fine particles contained in the intake air. The liquid concentration sensor 38 provides information on the concentration of fine particles in the stored liquid 68. By using these sensors, the length of time the fine particle sampling device 10 performs fine particle sampling, the timing of when the fine particle sampling device 10 starts operating the fine particle sampling operation, and the timing of when it stops operating the fine particle sampling operation can be set to the user's desired conditions. For example, "10,000 particles / cm²" 3 "Air with this particle concentration has arrived, so operation will begin," "1m 3 Examples include "The air has been processed, so operation is complete" and "The level has reached 1000 cells / mL, so operation is complete," allowing for the selection of the optimal sampling method according to the sampling application.

[0090] By adding a function to read the current simultaneously when applying a high voltage, it is possible to suppress the supply of more liquid 68 than necessary and to suppress the depletion of liquid 68. Specifically, the current value measured by the ammeter 40 is read, and when the current value exceeds a predetermined threshold, the control unit 90 causes the supply unit 28 to supply the minimum amount of liquid 68 into the main body 56 of the first electrode 22. This makes it possible to maintain a high concentration of fine particles in the stored liquid 68 as much as possible.

[0091] As described above, the particulate sampling device 10 according to this embodiment can recover influenza virus 1 from the air into liquid 68 at a high concentration. By combining information obtained from various sensors, sampling can be performed efficiently, and sampling can be performed under optimal conditions according to the user's purpose.

[0092] The particulate sampling device 10 may also classify aerosols containing influenza viruses from the air into two particle size ranges and recover them in the liquid 68. This allows for the analysis of the amount of influenza virus in each particle size range.

[0093] The particulate sampling device 10 can accumulate particulate matter in the liquid 68 stored in the first electrode 22 without circulating the liquid 68, making it easy to collect particulate matter to achieve a high concentration of particulate matter in the liquid 68. The particulate sampling device 10 does not require equipment to circulate the liquid 68, making it a device that can be easily miniaturized and energy-saving.

[0094] Figure 8 shows the experimental results of an experiment conducted to confirm the amount of ozone generated and the dust collection efficiency with and without the covering member 102. The experimental results shown in Figure 8 are from an experiment using a first electrode 22 with an inner diameter of 15 mm, a second electrode 24 and core member 100 with an outer diameter of 150 μm, and a covering member 102 with an outer diameter of 2.6 mm, with a dust collection flow rate of 30 L / min, a target particle size of 1 μm, and an applied voltage of 6 kV. Gas was introduced into the first electrode 22 from one end (the end on the first flange member 18 side). In the case with the covering member 102, approximately 70% of the linear members constituting the second electrode 24 and core member 100 (i.e., approximately 70% of I1 + I2) were covered by the covering member 102.

[0095] As shown in Figure 8, when no covering is applied, i.e., when the covering member 102 is not present, the amount of ozone generated is 0.66 ppm, and when approximately 70% is covered, i.e., when the covering member 102 is present, the amount of ozone generated is 0.19 ppm. By providing the covering member 102, the amount of ozone generated is suppressed.

[0096] When no coating is applied, i.e., when the coating member 102 is not present, the dust collection efficiency is approximately 85%, and when approximately 70% is coated, i.e., when the coating member 102 is present, the dust collection efficiency is approximately 90%. For example, dust collection efficiency is the ratio of the number of target particles collected in the liquid 68 to the number of target particles in the gas before it flows into the first electrode 22. By providing the coating member 102, the dust collection efficiency was improved.

[0097] Furthermore, the thicker the covering member 102, the smaller the gap between the covering member 102 and the first electrode 22, and the higher the electric field strength between the covering member 102 and the first electrode 22, thus improving the collection efficiency.

[0098] As described above, the particulate sampling device 10 according to this embodiment is a particulate sampling device comprising: a cylindrical first electrode 22 having a first opening located at a first end in the axial direction of the cylinder and a second opening located at a second end in the axial direction of the cylinder; a second electrode 24 extending in the axial direction and positioned within the first electrode 22 at a distance from the inner surface 66 of the first electrode 22; a third electrode 25 extending in the axial direction and positioned within the first electrode 22 at a distance from the inner surface 66; and the third electrode 25 being thicker than the second electrode 24. The positions of electrode 25 and second electrode 24 differ in the axial direction. The device includes a supply unit 28 that supplies liquid 68 into the first electrode 22 and stores the liquid 68 in a portion of the inner surface 66 of the first electrode 22 in the direction of the axis B, a voltage application unit 26 that applies a first voltage between the first electrode 22 and the second electrode 24, and a second voltage between the first electrode 22 and the third electrode 25, a drive unit 32 that rotates the first electrode 22 around a rotation axis that extends in the axial direction and passes through the first electrode 22, and a recovery unit 30 that recovers the stored liquid 68.

[0099] According to this, since the third electrode 25 is thicker than the second electrode 24, the electric field is less likely to concentrate and discharge is less likely to occur between the third electrode 25 and the first electrode 22 than between the second electrode 24 and the first electrode 22. Therefore, the generation of active substances such as ozone can be suppressed between the third electrode 25 and the first electrode 22. Since the third electrode 25 is thicker than the second electrode 24, the electric field strength is higher between the third electrode 25 and the first electrode 22 than between the second electrode 24 and the first electrode 22. Therefore, when gas is flowed into the first electrode 22 from the end of the first electrode 22 that is closer to the second electrode 24, first, the discharge between the second electrode 24 and the first electrode 22 can easily charge the fine particles in the gas. Then, after the fine particles in the gas are charged, the electric field between the third electrode 25 and the first electrode 22 can easily cause the charged fine particles to adhere to the inner surface 66 of the first electrode 22. In this way, by making the third electrode 25 thicker than the second electrode 24 and positioning the second electrode 24 and the third electrode 25 at different positions in the axial direction of the first electrode 22, fine particles can be efficiently sampled while suppressing the generation of active substances. The first voltage and the second voltage may be the same potential or different potentials.

[0100] In the particulate sampling apparatus 10 according to this embodiment, the third electrode 25 is arranged in the axial direction alongside the second electrode 24.

[0101] According to this, it is possible to suppress the increase in size of the fine particle sampling device 10 in the direction perpendicular to the axial direction of the first electrode 22, and to efficiently sample fine particles while suppressing the generation of active substances.

[0102] In the particulate sampling device 10 according to this embodiment, the third electrode 25 is longer than the second electrode 24 within the first electrode 22.

[0103] According to this, the section where discharge is difficult and the electric field strength is high becomes longer than the section where discharge is easy, so the generation of active substances can be further suppressed and fine particles can be sampled more efficiently.

[0104] In the particulate sampling apparatus 10 according to this embodiment, within the first electrode 22, the second electrode 24 is positioned between the first opening and the first surface, and not between the first surface and the second opening; within the first electrode 22, the third electrode 25 is positioned between the first surface and the second opening, and not between the first opening and the first surface; the second electrode 24 and the third electrode 25 are in direct contact at the first surface; the distance between the first surface and the first opening is smaller than the distance between the first surface and the second opening; The first face and the axial direction are perpendicular.

[0105] According to this, the second electrode 24 is positioned on one end side of the central G, so the length of the second electrode 24 can be suppressed, and the generation of active substances can be further suppressed. The third electrode 25 extends from one end side of the central G to the opposite side of the other end, so the third electrode 25 can be made longer on the other end side than the second electrode 24, and fine particles can be sampled even more efficiently.

[0106] In the particulate sampling apparatus 10 according to this embodiment, at least a portion of the third electrode 25 is formed integrally with the second electrode 24.

[0107] According to this, at least a portion of the third electrode 25 and the second electrode 24 can be easily formed from a single component.

[0108] In the particulate sampling device 10 according to this embodiment, the third electrode 25 has a core member 100 extending in the axial direction and a covering member 102 that is conductive and covers the core member 100.

[0109] According to this, by covering the core member 100 with the covering member 102, the third electrode 25 can be easily made thicker than the second electrode 24.

[0110] In the particulate sampling device 10 according to this embodiment, the core member 100 is formed integrally with the second electrode 24 such that the core member 100 and the second electrode 24 are continuous in the axial direction.

[0111] According to this, the core member 100 and the second electrode 24 can be easily formed from a single conductive material, and the covering member 102 makes it easier to make the third electrode 25 thicker than the second electrode 24.

[0112] The particulate sampling device 10 according to this embodiment further includes an air velocity sensor 34, and the control unit 90 determines that the measured value of the air velocity sensor 34 indicates the air velocity of the gas in the first electrode 22.

[0113] According to this, the wind speed of the gas passing through the first electrode 22 can be measured, making it easy to determine whether or not gas is flowing through the first electrode 22. For example, by applying a voltage when gas is flowing through the first electrode 22, it becomes easier to collect fine particles, thus enabling more efficient sampling of fine particles. In this way, the time and timing of applying voltage between the first electrode 22 and the second electrode 24 and between the first electrode 22 and the third electrode 25, the timing of ending the voltage application, and the timing of starting the recovery of the liquid 68 can be adjusted according to the wind speed information from the wind speed sensor 34. This makes it easy to perform sampling at the optimal and appropriate timing and operating time according to the application and purpose of sampling.

[0114] The particulate sampling device 10 according to this embodiment further includes a control unit 90 that calculates the gas flow rate based on the measurement results of the wind speed sensor 34 and outputs the flow rate.

[0115] According to this, the timing of ending the voltage application and the timing of starting the recovery of the liquid 68 can be adjusted based on the flow rate of the gas that has passed through the first electrode 22, thereby enabling more efficient sampling of fine particles.

[0116] The particulate sampling device 10 according to this embodiment further includes an air concentration sensor 36. The control unit 90 determines that the measurement value of the air concentration sensor 36 indicates the concentration of particulate matter in the gas within the first electrode 22, and the control unit 90 controls the voltage application unit 26 and the drive unit 32 based on the measurement result of the air concentration sensor 36.

[0117] According to this, when a concentration higher than a predetermined concentration is measured, applying a voltage and rotating the first electrode 22 makes it easier to collect fine particles in the gas. In this way, by operating the system when a gas with a desired concentration of fine particles is introduced, fine particles can be sampled even more efficiently.

[0118] The particulate sampling device 10 according to this embodiment further includes a liquid concentration sensor 38 for measuring the concentration of particulate matter in the stored liquid 68, and the control unit 90 stops applying voltage by the voltage application unit 26 when the concentration measured by the liquid concentration sensor 38 is higher than a predetermined concentration.

[0119] According to this method, when fine particles accumulate in the liquid 68 and the concentration of fine particles in the liquid 68 exceeds a predetermined concentration, the voltage application can be stopped and sampling can be terminated. Therefore, it is possible to avoid unnecessarily prolonging the sampling time and the situation where the concentration of fine particles in the liquid 68 becomes too dilute to analyze, and fine particles can be sampled more efficiently.

[0120] The particulate sampling device 10 according to this embodiment further includes an ammeter 40 that measures the value of a first current flowing between the first electrode 22 and the second electrode 24, the value of a second current flowing between the first electrode 22 and the third electrode 25, or the value of a third current based on the first and second currents. The control unit 90 causes the supply unit 28 to replenish the liquid 68 in the first electrode 22 if the current value measured by the ammeter 40 is greater than a predetermined value.

[0121] According to this, the value of the first current flowing between the first electrode 22 and the second electrode 24, the value of the second current flowing between the first electrode 22 and the third electrode 25, or the value of the third current based on the first and second currents can be measured. If the measured current value is greater than a predetermined value, the supply unit 28 replenishes the liquid 68 in the first electrode 22. For example, if the amount of liquid 68 decreases over time and the current value exceeds a predetermined value, a predetermined amount of liquid 68 can be replenished. This prevents a decrease in the concentration of fine particles due to an excessive amount of liquid 68 stored in the first electrode 22, and also prevents the liquid 68 from being depleted. Therefore, fine particles can be sampled more efficiently.

[0122] In the particulate sampling device 10 according to this embodiment, the inner surface 66 of the first electrode 22 is subjected to a hydrophilic treatment.

[0123] According to this, when fine particles adhering to the inner surface 66 come into contact with the stored liquid 68, they become more likely to detach from the inner surface 66. Therefore, losses when recovering fine particles collected on the inner surface 66 can be suppressed, and fine particles can be sampled more efficiently.

[0124] In the particulate sampling device 10 according to this embodiment, a adhesion suppression member is attached to the inner surface 66 of the first electrode 22 to suppress the adhesion of particulate matter.

[0125] According to this, when fine particles adhering to the inner surface 66 come into contact with the stored liquid 68, they become more likely to detach from the inner surface 66. Therefore, losses when recovering fine particles collected on the inner surface 66 can be suppressed, and fine particles can be sampled more efficiently.

[0126] In the particulate sampling apparatus 10 according to this embodiment, the liquid 68 is a liquid for analyzing particulate matter in the liquid.

[0127] According to this method, target substances contained in fine particles can be easily extracted. By selecting an appropriate liquid 68 according to the purpose and / or application, it is possible to implement an appropriate detection protocol and / or prevent damage to the sample.

[0128] (Second Embodiment) Figure 9 is a cross-sectional view of the particulate sampling device 10a according to the second embodiment. The particulate sampling device 10a according to the second embodiment will be described with reference to Figure 9.

[0129] As shown in Figure 9, the particulate sampling device 10a comprises a second electrode 24a and a third electrode 25a. The particulate sampling device 10a differs from the particulate sampling device 10 mainly in that the third electrode 25a is separate from the second electrode 24a.

[0130] The third electrode 25a has a core member 100a extending in the axial direction of the first electrode 22 and a covering member 102a that is conductive and covers the core member 100a. The core member 100a and the covering member 102a are separate from the second electrode 24a. The third electrode 25a is positioned at a distance from the second electrode 24a in the axial direction of the first electrode 22. The first electric wire 74 may be electrically connected to the second electrode 24a via the first support 70 (not shown).

[0131] For example, when the second electrode 24a and the third electrode 25a are separated, the ammeter 40 is installed at a location where it can measure the current value of the current flowing between the first electrode 22 and the second electrode 24a, and measures the current value of the current flowing between the first electrode 22 and the second electrode 24a.

[0132] For example, the third electrode 25a may be in contact with the second electrode 24a. For example, the third electrode 25a does not have to be positioned alongside the second electrode 24a in the axial direction of the first electrode 22. In other words, for example, the third electrode 25a may be positioned so as not to overlap with the second electrode 24a when viewed from the axial direction of the first electrode 22.

[0133] (Third embodiment) Figure 10 is a cross-sectional view of the particulate sampling device 10b according to the third embodiment. The particulate sampling device 10b according to the third embodiment will be described with reference to Figure 10.

[0134] As shown in Figure 10, the particulate sampling device 10b comprises a second electrode 24b and a third electrode 25b. The particulate sampling device 10b differs from the particulate sampling device 10 mainly in that the third electrode 25b does not have a covering member 102, and the third electrode 25b is composed of a single conductive member that is thicker than the second electrode 24b.

[0135] The third electrode 25b is integrally formed with the second electrode 24b. For example, by tapering one end of a rod-shaped conductive member, the second electrode 24b and the third electrode 25b can be integrally formed from a single conductive member.

[0136] For example, the third electrode 25b may be separate from the second electrode 24b, or it may be positioned at a distance from the second electrode 24b.

[0137] (Other embodiments, etc.) In the embodiment described above, the case in which the third electrode 25 is longer than the second electrode 24 within the first electrode 22 was explained, but the invention is not limited to this. For example, within the first electrode, the third electrode may be shorter than the second electrode.

[0138] In the embodiments described above, the second electrode 24 is positioned within the first electrode 22, on one end side of the center G in the axial direction of the first electrode 22 and on the other end side of the center G, with the second electrode 24 positioned on the side of the center G. However, the invention is not limited to this. For example, the second electrode may be positioned within the first electrode, extending from one end side of the center of the first electrode to the other end side of the center.

[0139] In the embodiment described above, the third electrode 25 is described as extending from one end of the first electrode 22 to the opposite side of the other end of the first electrode 22, beyond the axial center G of the first electrode 22. However, the embodiment is not limited to this. For example, the third electrode may be positioned within the first electrode, on the other end side of the first electrode, beyond the axial center of the first electrode.

[0140] In the embodiment described above, the case in which the core member 100 is approximately the same thickness as the second electrode 24 was explained, but the invention is not limited to this. For example, the core member may be thicker than the second electrode, or it may be thinner than the second electrode. For example, if the core member is thinner than the second electrode, the third electrode can be made thicker than the second electrode by covering the core member with a covering member.

[0141] In the embodiments described above, the case in which the particulate sampling device 10 comprises a second electrode 24 and a third electrode 25 was described, but it is not limited to this. For example, the particulate sampling device may comprise a plurality of second electrodes and a plurality of third electrodes. In this case, for example, the second electrodes and third electrodes may be arranged alternately in the axial direction of the first electrode.

[0142] In the embodiments described above, the case in which the body 56 of the first electrode 22 is cylindrical was explained, but the invention is not limited to this. For example, the body of the first electrode may be an elliptical cylinder, a polygonal cylinder, or the like.

[0143] In the embodiment described above, the case in which the first electrode 22 is installed with the axis B of the main body 56 parallel to the horizontal direction was explained, but the invention is not limited to this, and the first electrode 22 does not have to be installed with the axis B of the main body 56 parallel to the horizontal direction. For example, the first electrode 22 may be installed with the axis B of the main body 56 tilted with respect to the horizontal direction, and it is sufficient that the liquid 68 can be stored in a part of the inner surface 66 in the direction of the axis B of the main body 56 so that the liquid 68 does not flow out to the outside of the main body 56. In other words, the first electrode 22 just needs to be positioned in a way that allows the liquid 68 to be stored on the inner surface 66.

[0144] In the embodiment described above, the case in which the second electrode 24 is installed in a position in which the axis of the second electrode 24 coincides with the axis B of the body 56 of the first electrode 22 was explained. However, the embodiment is not limited to this, and the second electrode 24 does not have to be installed in a position in which the axis of the second electrode 24 coincides with the axis B of the body 56 of the first electrode 22. For example, the second electrode 24 may be installed in a position in which the axis of the second electrode 24 is tilted with respect to the axis B of the body 56, and it is sufficient that it extends in the axial direction of the body 56 of the first electrode 22. For example, the second electrode 24 may be installed in a position in which the axis of the second electrode 24 does not coincide with the axis B of the body 56 of the first electrode 22, and the axis of the second electrode 24 is parallel to the axis B of the body 56 of the first electrode 22.

[0145] In the embodiment described above, the case in which the third electrode 25 is installed in a position in which the axis of the third electrode 25 coincides with the axis B of the body 56 of the first electrode 22 was explained. However, the embodiment is not limited to this, and the third electrode 25 does not have to be installed in a position in which the axis of the third electrode 25 coincides with the axis B of the body 56 of the first electrode 22. For example, the third electrode 25 may be installed in a position in which the axis of the third electrode 25 is tilted with respect to the axis B of the body 56, and it is sufficient that it extends at least in the axial direction of the body 56 of the first electrode 22. For example, the third electrode 25 may be installed in a position in which the axis of the third electrode 25 does not coincide with the axis B of the body 56 of the first electrode 22, and the axis of the third electrode 25 is parallel to the axis B of the body 56 of the first electrode 22.

[0146] In the embodiments described above, the case in which the second electrode 24 is linear was explained, but the invention is not limited to this. For example, the second electrode may be plate-shaped or needle-shaped, etc.

[0147] In the embodiments described above, the core member 100 was described as being linear, but the invention is not limited to this. For example, the core member may be plate-shaped or needle-shaped.

[0148] In the embodiment described above, the case in which the second electrode 24 protrudes outward from one end of the main body 56 was explained, but the embodiment is not limited to this. For example, the second electrode does not have to protrude outward from the first electrode.

[0149] In the embodiment described above, the case in which the third electrode 25 protrudes outward from the other end of the main body 56 was explained, but the embodiment is not limited to this. For example, the third electrode does not have to protrude outward from the first electrode.

[0150] In the embodiment described above, the case in which the drive unit 32 rotates the first electrode 22 around the axis B of the body 56 of the first electrode 22 was explained, but it is not limited to this. For example, the drive unit may rotate the first electrode around a rotation axis that is slightly inclined with respect to the axis of the body of the first electrode. The drive unit may rotate the first electrode around a rotation axis that is parallel to the axis of the body of the first electrode. The drive unit may rotate the first electrode around a rotation axis that extends in the axial direction of the first electrode and passes through the first electrode. [Industrial applicability]

[0151] This disclosure is widely applicable to devices for sampling fine particles such as aerosols from gases such as air. [Explanation of Symbols]

[0152] 10, 10a, 10b Particulate sampling device 12 ducts 14. First bearing seal 16. Second bearing seal 18. First flange member 20 Second flange member 22 1st electrode 24,24a,24b 2nd electrode 25,25a,25b 3rd electrode 26 Voltage application section 28 Supply section 30. Recovery Section 32 Drive unit 34 Wind speed sensor 36. Airborne concentration sensor 38 Liquid concentration sensor 40 ammeter 42, 48, 52, 56 Main unit 44 1st support part 46 Second support part 50, 54 flange 58 First outer flange 60 Second outer flange 62 First inner flange 64 Second inner flange 66 Inner self 68 liquid 69 Space 70 First support 72 Second support 74. First power line 76. Second power line 78 tanks 80 Injection part 82 tanks 84 Extraction part 86 Gear 88 Motor 90 Control Unit 100,100a Core member 102,102a Covering member

Claims

1. A first electrode having a cylindrical shape, a first opening located at the first end of the cylinder in the axial direction, and a second opening located at the second end of the cylinder in the axial direction, A second electrode extending in the axial direction and positioned within the first electrode at a distance from the inner surface of the first electrode, A third electrode extending in the axial direction and positioned within the first electrode at a distance from the inner surface, wherein the third electrode is thicker than the second electrode. A supply unit that supplies liquid into the first electrode and stores the liquid in a part of the inner surface in the direction of the axis of the first electrode, A voltage application unit that applies a first voltage between the first electrode and the second electrode, and a second voltage between the first electrode and the third electrode, A drive unit that rotates the first electrode about a rotation axis that extends in the axial direction and passes through the first electrode, The system includes a recovery unit for recovering the stored liquid, The positions of the third electrode and the second electrode are different in the axial direction. A particulate sampling device.

2. The third electrode is arranged in the axial direction alongside the second electrode, The particulate sampling apparatus according to claim 1.

3. Within the first electrode, the third electrode is longer than the second electrode. The particulate sampling apparatus according to claim 1 or 2.

4. Within the first electrode, the second electrode is positioned between the first opening and the first surface, and is not positioned between the first surface and the second opening. Within the first electrode, the third electrode is not positioned between the first opening and the first surface, but is positioned between the first surface and the second opening. The second electrode and the third electrode are in direct contact on the first surface. The distance between the first surface and the first opening is smaller than the distance between the first surface and the second opening. The first surface and the axial direction are perpendicular. The particulate sampling apparatus according to claim 3.

5. At least a portion of the third electrode is formed integrally with the second electrode. A particulate sampling apparatus according to any one of claims 1 to 4.

6. The third electrode comprises a core member extending in the axial direction and a covering member that is conductive and covers the core member. A particulate sampling apparatus according to any one of claims 1 to 5.

7. The core member is formed integrally with the second electrode such that the second electrode and the core member are continuous in the axial direction. The particulate sampling apparatus according to claim 6.

8. Further comprising a control unit and an anemometer, The control unit determines that the measured value of the wind speed sensor indicates the wind speed of the gas in the first electrode. A particulate sampling apparatus according to any one of claims 1 to 7.

9. The control unit calculates the flow rate of the gas based on the measurement result of the wind speed sensor and outputs the flow rate. The particulate sampling apparatus according to claim 8.

10. The system further includes an air concentration sensor, and the control unit determines that the measured value of the air concentration sensor indicates the concentration of fine particles in the gas within the first electrode. The control unit controls the voltage application unit and the drive unit based on the measurement results of the air concentration sensor. The particulate sampling apparatus according to claim 9.

11. The system further includes a liquid concentration sensor for measuring the concentration of fine particles in the stored liquid, The control unit stops applying voltage by the voltage application unit if the concentration measured by the liquid concentration sensor is higher than a predetermined concentration. The particulate sampling apparatus according to claim 9 or 10.

12. The system further comprises an ammeter for measuring the value of a first current flowing between the first electrode and the second electrode, the value of a second current flowing between the first electrode and the third electrode, or the value of a third current based on the first current and the second current. The control unit, when the current value measured by the ammeter is greater than a predetermined value, causes the supply unit to replenish the liquid in the first electrode. A particulate sampling apparatus according to any one of claims 9 to 11.

13. The inner surface of the first electrode is subjected to a hydrophilic treatment. A particulate sampling apparatus according to any one of claims 1 to 12.

14. A adhesion-suppressing member is attached to the inner surface of the first electrode to suppress the adhesion of fine particles. A particulate sampling apparatus according to any one of claims 1 to 13.

15. The liquid is a liquid for analyzing fine particles in the liquid. A particulate sampling apparatus according to any one of claims 1 to 14.

16. A method for sampling fine particles for a fine particle sampling device, The aforementioned particulate sampling device is A first electrode having a cylindrical shape, a first opening located at the first end of the cylinder in the axial direction, and a second opening located at the second end of the cylinder in the axial direction, A second electrode extending in the axial direction and positioned within the first electrode at a distance from the inner surface of the first electrode, The electrode comprises a third electrode that extends in the axial direction and is positioned within the first electrode at a distance from the inner surface, The third electrode is thicker than the second electrode, and the positions of the third electrode and the second electrode differ in the axial direction. The aforementioned fine particle sampling method is A liquid is supplied into the first electrode, and the liquid is stored in a portion of the inner surface in the direction of the axis of the first electrode. A first voltage is applied between the first electrode and the second electrode, and a second voltage is applied between the first electrode and the third electrode. The first electrode is rotated about a rotation axis that extends in the axial direction and passes through the first electrode, This includes recovering the stored liquid, A method for sampling fine particles.

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