Fine particle sampling device

Abstract

A fine particle sampling device (10) for sampling fine particles in a liquid comprises: a cylindrical first electrode (22); a second electrode (24) extending in the axial direction of the first electrode (22) and disposed in the first electrode (22) at an interval from an inner surface (66) of the first electrode (22); a duct (12) surrounding the first electrode (22); a first cylindrical part (19) connected to one end of the duct (12); a second cylindrical part (21) connected to the other end of the duct (12); a voltage application part (26) for applying a voltage across the first electrode (22) and the second electrode (24); and a drive part (36) for rotating the first electrode (22). The first cylindrical part (19) or the second cylindrical part (21) has a through-hole (33). The through-hole (33) is positioned above the liquid surface (68a) of a liquid (68) stored at a section of the inner surface (66) in the direction around the axis of the first electrode (22), and the through-hole (33) is a hole for recovering the liquid (68) via the through-hole (33).

Description

Particulate sampling device

[0001] The present disclosure relates to a particulate sampling device for sampling particulates.

[0002] Conventionally, there has been known an apparatus and method for sampling fine particles in a gas using a device that utilizes the inertia or centrifugal force of the fine particles (see, for example, Patent Document 1). More specifically, Patent Document 1 discloses an apparatus and method that generates an electrostatic force using a rotating cylindrical electrode to which a collection liquid (collection liquid) is supplied, thereby separating objects to be collected, such as fine particles, from air and collecting them in the liquid.

[0003] International Publication No. 2021 / 153155

[0004] In such conventional particle sampling devices, when repeated sampling is performed, the collected liquid is collected in the same collection section each time. This raises the concern that residues of particles collected in the previous sampling may remain in the collection section. Therefore, when repeated sampling is performed, there is a risk that the collected liquid may be contaminated with the previously collected liquid. In such cases, there is a problem in that accurate information cannot be obtained when analyzing the collected liquid.

[0005] The present disclosure provides a recovery technique that can suppress contamination of a collection liquid caused by the previous operation of recovering the collection liquid when recovering the collection liquid stored inside a cylindrical electrode in a device for sampling fine particles.

[0006] A particle sampling device according to one embodiment of the present disclosure is a particle sampling device for sampling particles in a liquid, and comprises: a cylindrical first electrode having open ends in its axial direction; a second electrode extending in the axial direction of the first electrode and positioned within the first electrode at a distance from the inner surface of the first electrode; a duct surrounding the first electrode; a first tubular portion connected to one end of the duct; a second tubular portion connected to the other end of the duct; a voltage application unit that applies a voltage between the first electrode and the second electrode; and a drive unit that rotates the first electrode, wherein the first tubular portion or the second tubular portion has a through hole that is located above the liquid level of the liquid stored in a portion of the inner surface in the direction around the axis of the first electrode, and the through hole is a hole for recovering the liquid through the through hole.

[0007] According to the present disclosure, it is possible to provide a particulate sampling device that suppresses contamination of the collection liquid.

[0008] FIG. 1 is a perspective view showing the appearance of a particle sampling device according to a first embodiment. FIG. 2 is a side view showing the appearance of the particle sampling device of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is an end view taken along line IV-IV in FIG. 1. FIG. 5 is a side view showing an example of a recovery machine according to the first embodiment. FIG. 6 is a cross-sectional view taken along line III-III in FIG. 1 when the recovery machine of FIG. 5 is inserted into the particle sampling device of FIG. 1. FIG. 7 is an end view taken along line IV-IV in FIG. 1 when the recovery machine of FIG. 5 is inserted into the particle sampling device of FIG. 1. FIG. 8 is a block diagram showing the configuration of the particle sampling device of FIG. 1. FIG. 9 is a cross-sectional view taken along line III-III in FIG. 1, and is an explanatory view for explaining an example of an operation performed by the particle sampling device of FIG. 1.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] However, the particle sampling device according to the present disclosure is not intended to be limited to the configurations shown in the embodiments or drawings described below, and also includes configurations equivalent thereto.

[0011] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the scope of the claims. Furthermore, the drawings are not necessarily strict illustrations. In the drawings, substantially identical components are designated by the same reference numerals, and duplicated descriptions may be omitted or simplified.

[0012] In the following, terms indicating the relationship between elements, such as parallel and perpendicular, terms indicating the shape of elements, such as cylindrical, and numerical ranges do not only represent the strict meaning, but also include a substantially equivalent range, for example, a difference of a few percent.

[0013] In the following figures, the X-axis and Y-axis are axes that are perpendicular to each other on a horizontal plane. The Z-axis is an axis that is perpendicular to the horizontal plane. On the Z-axis, the positive direction represents a vertically upward direction, and the negative direction represents a vertically downward direction.

[0014] (Embodiment) Fig. 1 is a perspective view showing the appearance of a particle sampling device 10 according to an embodiment. Fig. 2 is a side view showing the appearance of the particle sampling device 10 of Fig. 1. Fig. 3 is an internal view of the particle sampling device 10 of Fig. 1, and is a cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is an end view taken along line IV-IV in Fig. 1. The particle sampling device 10 according to an embodiment will be described with reference to Figs. 1 to 4.

[0015] 1 to 4 , the particle sampling device 10 is a device that samples particles in a liquid. Specifically, the particle sampling device 10 samples particles in a liquid 68 (described below) by capturing particles in a gas in the liquid. For example, the particles include fungi, bacteria, viruses, aerosols, etc. The particle sampling device 10 includes a duct 12, a first bearing seal 14, a second bearing seal 16, a first flange 18, a first cylindrical portion 19, a second flange 20, a second cylindrical portion 21, a first electrode 22, a second electrode 24, a voltage application unit 26, a supply unit 28, and a drive unit 36.

[0016] The particle sampling device 10 is configured by surrounding a rotating first electrode 22 and a second electrode 24 disposed at the center of the first electrode 22 with a duct 12, a first cylindrical portion 19, and a second cylindrical portion 21. A gas such as air is passed through the particle sampling device 10 in a direction that passes through the particle sampling device 10 (the direction indicated by arrow A in FIG. 2 ). For example, air may be drawn directly into the particle sampling device 10 by a pump or fan (not shown), and the gas may be passed through the particle sampling device 10. Alternatively, the particle sampling device 10 may be installed in a device that generates a gas flow, such as an air conditioner, air purifier, or ventilation vent, and the air may be drawn into the particle sampling device 10 for processing. By attaching the particle sampling device 10 to a device that generates a gas flow, it is not necessary to incorporate a pump or other device for generating a gas flow into the particle sampling device 10. This allows for a compact, quiet device with low pressure loss to be easily realized. This allows for installation and incorporation in a variety of locations.

[0017] Each component of the particle sampling device 10 will be described below.

[0018] 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.

[0019] The main body 42 is cylindrical, with one end and the other end in the axial direction of the main body 42 open. The first support portion 44 protrudes radially outward from one end of the main body 42 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 generally U-shaped (see FIG. 3 ). The first support portion 44 is annular when viewed axially of the main body 42. A first bearing seal 14 is disposed inside the first support portion 44. The first bearing seal 14 seals the gap between the first support portion 44 and a first outer flange 58 (described below) to prevent gas leakage between the first support portion 44 and the first outer flange 58. The first support portion 44 rotatably supports the first electrode 22 via the first bearing seal 14. The second support portion 46 protrudes radially outward from the other axial end of the main body 42 and is integrally formed with the main body 42. The second support portion 46 is generally U-shaped and recessed radially outward from the main body 42 (see FIG. 3 ). The second support portion 46 is annular when viewed axially of the main body 42. A second bearing seal 16 is disposed inside the second support portion 46. The second bearing seal 16 seals the gap between the second support portion 46 and the second outer flange 60 (described below) to prevent gas from leaking between the second support portion 46 and the second outer flange 60. The second support portion 46 rotatably supports the first electrode 22 via the second bearing seal 16.

[0020] The first cylindrical portion 19 is cylindrical, and one end and the other end in the axial direction of the first cylindrical portion 19 are open. One end of the first cylindrical portion 19 is connected to the duct 12, and the other end of the first cylindrical portion 19 is connected to the first flange 18. The second cylindrical portion 21 is cylindrical, and one end and the other end in the axial direction of the second cylindrical portion 21 are open. One end of the second cylindrical portion 21 is connected to the duct 12, and the other end of the second cylindrical portion 21 is connected to the second flange 20.

[0021] The first flange 18 protrudes radially outward from one end of the first cylindrical portion 19 in the axial direction of the first cylindrical portion 19 and is formed integrally with the first cylindrical portion 19. When viewed from the axial direction of the first cylindrical portion 19, the first flange 18 has an annular shape.

[0022] The second flange 20 protrudes radially outward from one end of the second cylindrical portion 21 in the axial direction of the second cylindrical portion 21 and is formed integrally with the second cylindrical portion 21. When viewed from the axial direction of the second cylindrical portion 21, the second flange 20 is annular.

[0023] The first electrode 22 is cylindrical, and both axial ends of the first electrode 22 are open. The first electrode 22 is connected to ground via a second electric wire 76 or the like. The first electrode 22 has a main portion 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 main portion 56, the first outer flange 58, the second outer flange 60, the first inner flange 62, and the second inner flange 64 are formed using stainless steel such as SUS (Steel Special Use Stainless Steel).

[0024] The main portion 56 is cylindrical, with one end and the other end in the axial direction of the main portion 56 being open. The axial direction of the main portion 56 is the direction in which the axis B of the main portion 56 extends (the X-axis direction). The main portion 56 has external teeth (not shown) on its outer circumferential surface that mesh with external teeth (not shown) of a gear 86 (described below). The inner surface 66 of the main portion 56 is hydrophilized. The hydrophilization treatment here is performed by surface modification using plasma treatment or alkali treatment using potassium hydroxide (KOH). Alternatively, it can be performed by coating or applying a surfactant, for example. An adhesion inhibitor that inhibits adhesion of fine particles is attached to the inner surface 66 of the main portion 56. For example, the adhesion inhibitor is a blocking agent such as skim milk, BSA (Bovine Serum Albumin), or PEG (Polyethylene Glycol).

[0025] Alternatively, when sampling, a solution containing an amphiphilic polymer (a polymer having a hydrophilic group and a hydrophobic group at each end) is supplied into the electrode as a sampling solution, and the electrode is rotated for, for example, about one minute to bring the sampling solution into contact with the entire inner surface of the electrode, thereby performing a hydrophilic treatment.

[0026] The first outer collar portion 58 protrudes radially outward from one axial end of the main portion 56 and is formed integrally with the main portion 56. The first outer collar portion 58 is annular about the axis B of the main portion 56. In other words, the first outer collar portion 58 is annular when viewed from the axial direction of the main portion 56. The first outer collar portion 58 is disposed inward of the first bearing seal 14.

[0027] The second outer collar portion 60 protrudes radially outward from the other axial end of the main portion 56 and is formed integrally with the main portion 56. The second outer collar portion 60 is annular about the axis B of the main portion 56. In other words, the second outer collar portion 60 is annular when viewed from the axial direction of the main portion 56. The second outer collar portion 60 is disposed inside the second bearing seal 16.

[0028] The first inner flange 62 protrudes radially inward from one axial end of the main portion 56 and is formed integrally with the main portion 56. The first inner flange 62 is annular about the axis B of the main portion 56. In other words, the first inner flange 62 is annular when viewed from the axial direction of the main portion 56. The inward tip of the first inner flange 62 is the tip 63.

[0029] The second inner flange 64 protrudes radially inward from the other axial end of the main portion 56 and is formed integrally with the main portion 56. The second inner flange 64 is annular about the axial center B of the main portion 56. In other words, the second inner flange 64 is annular when viewed from the axial direction of the main portion 56. The inward tip of the second inner flange 64 is the tip 65.

[0030] The first electrode 22 is installed with the axis B of the main portion 56 parallel to the horizontal direction. The first electrode 22 is supported so as to be rotatable around the axis B of the main portion 56 (see arrow C in FIG. 4 ). In other words, the first electrode 22 is supported so as to be rotatable on its axis.

[0031] The first electrode 22 stores a liquid 68 on the inner surface 66 of the main portion 56. Specifically, the first electrode 22 stores the liquid 68 in a portion of the inner surface 66 in a direction around the axis B of the main portion 56 (see arrow D in FIG. 4 ). The stored liquid 68 is located below the axis B of the main portion 56. The first electrode 22 also stores the liquid 68 in that portion of the inner surface 66 along the axial direction of the main portion 56. The first inner flange 62 holds the liquid 68 so that the liquid 68 stored in the portion of the inner surface 66 of the main portion 56 does not spill out from one end of the main portion 56 in the axial direction. The second inner flange 64 holds the liquid 68 so that the liquid 68 stored in the portion of the inner surface 66 of the main portion 56 does not spill out from the other end of the main portion 56 in the axial direction. In this way, the first electrode 22 stores the liquid 68 in a part of the inner surface 66 of the main portion 56 so as to prevent the liquid 68 from flowing out of the main portion 56. Within the main portion 56, above the stored liquid 68, a space 69 is formed that passes through the main portion 56 in the axial direction.

[0032] The second electrode 24 is linear and extends in the axial direction of the main portion 56 of the first electrode 22. The second electrode 24 passes through the radially inner portion of the main portion 56 of the first electrode 22 and is positioned inside the main portion 56. That is, the second electrode 24 protrudes outward from one end of the main portion 56 and from the other end of the main portion 56 in the axial direction of the main portion 56. The second electrode 24 is spaced apart from the inner surface 66 of the main portion 56 of the first electrode 22 and is located near the center of the first electrode 22. The second electrode 24 is disposed within the space 69. In this embodiment, the second electrode 24 is disposed in such a manner that the axis of the second electrode 24 coincides with the axis B of the main portion 56 of the first electrode 22. For example, the second electrode 24 is formed of tungsten or the like.

[0033] The voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24. The voltage application unit 26 has a first support 70, a second support 72, a first electric wire 74, and a second electric wire 76.

[0034] The first support 70 is fixed to the first cylindrical portion 19 and is located inside the first cylindrical portion 19. 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 cylindrical portion 21 and is located inside the second cylindrical portion 21. The second support 72 is connected to the other axial end of the second electrode 24 and supports the second electrode 24. The first support 70 and the second support 72 are conductive and electrically connected to the second electrode 24. The first electric wire 74 is electrically connected to the second electrode 24 via the second support 72. The second electric wire 76 is electrically connected to the first electrode 22 via a gear 86 or the like.

[0035] The voltage application unit 26 can apply electricity of any magnitude and waveform to the first electrode 22 and the second electrode 24, which is installed near the center of the first electrode 22, via the first electric wire 74 and the second electric wire 76. This allows the particle sampling device 10 to perform electrostatic collection of particles. The second electrode 24 does not have to be linear; it can be plate-shaped, needle-shaped, or other similar. There are no limitations on its structure or installation position, as long as it is capable of forming 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.

[0036] For example, the voltage application unit 26 applies a voltage between the first electrode 22 and the second electrode 24 so that the second electrode 24 side is at a higher potential than the first electrode 22 side. This generates an electric field in the space 69 from the second electrode 24 toward the first electrode 22 (see arrow E in FIG. 3 and arrow E in FIG. 4 ). The supply unit 28 supplies the liquid 68 into the first electrode 22, causing the liquid 68 to accumulate on a portion of the inner surface 66 of the first electrode 22 in the direction around the axis B. In other words, the supply unit 28 supplies the liquid 68 into the first electrode 22 to accumulate on a portion of the inner surface 66 of the first electrode 22 in the direction around the axis B. In this way, the liquid 68 supplied by the supply unit 28 is accumulated on the inner surface 66 of the main portion 56 of the first electrode 22. The supply unit 28 includes a tank 78 and an injection unit 80. The tank 78 holds the liquid 68 to be supplied into the first electrode 22. The liquid 68 held in the tank 78 is discharged from the inlet 80 by a pump (not shown) or the like and supplied into the main portion 56 of the first electrode 22. The supply unit 28 may supply the liquid 68 from the opening side of the first electrode 22 (one end side of the main body 42 in the axial direction) as shown in FIG. 3 , or may supply the liquid from an opening formed in a side surface of the first electrode 22. In this embodiment, the supply unit 28 supplies the liquid 68 for analyzing the particles. For example, the liquid for analyzing the particles may refer to a liquid used in the analysis, a liquid that maintains the activity of the target substance contained in the particles for analysis, a liquid that labels the target substance contained in the particles for analysis, a liquid that protects the target substance contained in the particles for analysis, or any combination thereof. For example, if the target substance is influenza virus, liquids for preservation purposes such as physiological saline, PBS (Phosphate-Buffered Saline) buffer solution, EDTA (Ethylene Diamine Tetraacetic Acid) buffer solution, bicarbonate buffer solution, or liquids for dissolving viruses, liquids containing substances that specifically bind to viruses and emit magnetism or fluorescence, etc. Liquid 68 does not have to be a liquid for analyzing particles and may be, for example, pure water.

[0037] The target substance is not limited to influenza viruses. For example, the target substance may be another virus or a living organism other than a virus (e.g., a bacterium). Furthermore, the target substance does not have to be a living organism, and may be an environmental pollutant, an allergen, or the like.

[0038] The second cylindrical portion 21 has a through hole 33. The through hole 33 is a hole for recovering the liquid 68 stored in a portion of the inner surface 66 in the direction around the axis B of the first electrode 22. The through hole 33 is located above a liquid level 68a of the liquid 68 stored in the portion of the inner surface 66. A cylindrical guide tube 34 is inserted into the through hole 33. An axial straight line of the guide tube 34 (recovery straight line 100 in FIGS. 3 and 4 ) passes through the lowest point 67 of the inner surface 66 in the direction around the axis B of the first electrode 22. The recovery straight line 100 is angled so as not to intersect with the second electrode 24 (see FIG. 4 ). The guide tube 34 is preferably made of a rigid material that is not bendable, and is formed of a resin tube such as acrylic, ABS, or polyvinyl chloride, or glass.

[0039] The guide tube 34 protrudes radially inward from the second cylindrical portion 21. If the innermost portion of the guide tube 34 is defined as the innermost portion 35, the innermost portion 35 is located radially outward from the second cylindrical portion 21 relative to the tip 65 of the second inner flange 64. Here, when viewed from the direction of the axis B, the radial directions of the first cylindrical portion 19, the main portion 56, and the second cylindrical portion 21 can also be considered to be substantially the same direction. The through hole 33 may be located in the first cylindrical portion 19 instead of in the second cylindrical portion 21. In this case, the innermost portion 35 is located radially outward from the first cylindrical portion 19 relative to the tip 63 of the first inner flange 62.

[0040] In this embodiment, the case where the through hole 33 is provided in the second cylindrical portion 21 will be described, but the flow of the description in this embodiment will be similar to the case where the through hole 33 is provided in the first cylindrical portion 19. Specifically, when the through hole 33 is provided in the first cylindrical portion 19, as an example, the through hole 33 and / or the guide tube 34, etc. will be provided so as to be positioned symmetrically with respect to the y-z cross section passing through the center of the particle sampling device 10.

[0041] 5, the recovery machine 30 has a recovery section 31 and a cylindrical recovery tube 32. The recovery section 31 has a tank and a pump (not shown). The recovery tube 32 is preferably made of a hard material that does not bend, and is formed from a resin tube such as acrylic, ABS, or polyvinyl chloride, or glass.

[0042] 6 and 7 , the collection tube 32 of the collection device 30 is inserted into the guide tube 34 and reaches the lowest point 67 of the inner surface 66 along the collection line 100. When the collection tube 32 reaches the lowest point 67 of the inner surface 66, the collection device 30 operates the pump to suck the liquid 68 stored in a portion of the inner surface 66 through the collection tube 32 and collect it in a tank. In this manner, the liquid 68, such as the collection liquid in which the particulates have accumulated, is sucked through the collection tube 32 and held in the tank. In this embodiment, the collection device 30 operates to collect the entire amount of liquid 68 stored in the first electrode 22 (the entire amount of the preset storage amount).

[0043] The drive unit 36 ​​rotates the first electrode 22 around a rotation axis that extends in the axial direction of the main portion 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 main portion 56. That is, in this embodiment, the drive unit 36 ​​rotates the first electrode 22 around the axis B of the main portion 56 of the first electrode 22. The drive unit 36 ​​includes a gear 86 and a motor 88 for rotating the gear 86. The gear 86 has external teeth (not shown) that mesh with external teeth (not shown) of the first electrode 22. As the gear 86 is rotated by the motor 88, the first electrode 22 rotates around the axis B of the main portion 56 (see arrow C in FIG. 4 ). In this manner, the first electrode 22 is rotated by the gear 86 driven by the motor 88.

[0044] In addition, gas outside the particle sampling device 10 may pass through the inside of the second flange 20, pass through the inside of the main part 56 of the first electrode 22, and be released to the outside of the particle sampling device 10 from the first flange 18.

[0045] The pump or fan (not shown) corresponds to a blower that introduces gas from outside the particle sampling device 10 into the first electrode 22, and may draw air into the particle sampling device 10 in a direction that passes through the particle sampling device 10 (the direction indicated by arrow A in Figure 2).

[0046] The functional configuration of the particle sampling device 10 will be described with reference to FIG.

[0047] As shown in FIG. 8, the particle sampling device 10 further includes a control unit 90 therein.

[0048] The control unit 90 is electrically connected to the voltage application unit 26, the supply unit 28, and the drive unit 36. The control unit 90 controls the voltage application unit 26, the supply unit 28, and the drive unit 36. For example, the control unit 90 is realized by a microcomputer, but may also be realized by a processor or a dedicated circuit.

[0049] The setting unit 91 is included in the control unit 90. The setting unit 91 sets the operation time of collection, the voltage value applied by the voltage application unit 26, and the rotation speed of the drive unit 36. In addition, an air blower such as a pump or a fan that draws air into the first electrode 22 may be electrically connected and the air volume may be set. For example, the settings in the setting unit 91 may be adjusted by inputting numerical values ​​using a touch panel or by using a volume knob or the like.

[0050] Here, the upper limit of the amount of liquid that can be initially supplied by the supply unit 28 is set based on the amount of liquid that will reliably prevent insulation breakdown, etc., from occurring due to the distance between the liquid 68 stored in the first electrode 22 and the second electrode 24 becoming closer when a voltage is applied between the first electrode 22 and the second electrode 24.

[0051] Next, a description will be given of the operation of the particle sampling device 10 configured as described above. Fig. 9 is an explanatory diagram for explaining an example of the operation of the particle sampling device 10, showing the movement of viruses inside the particle sampling device 10 until the viruses are actually collected.

[0052] Specifically, the following describes an example of the operation of the particle sampling device 10 in this embodiment for capturing influenza viruses 1 and recovering the influenza viruses 1 in liquid. Here, an example is shown in which the particle sampling device 10 performs liquid collection with the aim of recovering influenza viruses 1, which are thought to be airbornely transmitted, as a liquid sample that can be analyzed by a sensor or the like.

[0053] First, the control unit 90 controls the supply unit 28 to supply the liquid 68 into the first electrode 22 and cause the liquid 68 to accumulate in a part of the inner surface 66 in the direction around the axis B of the first electrode 22. For example, the user may operate an arbitrary operation button or the like to activate the supply unit 28 and supply the liquid 68 into the main portion 56 of the first electrode 22.

[0054] Next, the control unit 90 controls the drive unit 36 ​​at the rotation speed set by the user, causing the drive unit 36 ​​to start operating and rotate the first electrode 22 around the axis B. For example, the user may operate any operation button or the like to activate the drive unit 36 ​​and rotate the first electrode 22. As a result, as shown in FIG. 9 , the first electrode 22 rotates around the axis B at the set rotation speed while retaining the liquid 68 on a portion of the inner surface 66 of the main portion 56 of the first electrode 22 in the direction around the axis B. In other words, the first electrode 22 rotates around the axis B while retaining the liquid 68 below the axis B so that the liquid 68 does not flow out of the main portion 56. As a result, the inner surface 66 of the first electrode 22 sequentially comes into contact with the retained liquid 68.

[0055] Next, the particle sampling device 10 operates a pump or fan at an airflow rate set by the user. This generates a desired air flow (see arrow A in FIG. 9 ). The control unit 90 controls the voltage application unit 26 to apply a voltage between the first electrode 22 and the second electrode 24 at a voltage value set by the user. For example, the user may operate an operation button or the like to operate the voltage application unit 26 and apply a voltage between the first electrode 22 and the second electrode 24. As a result, as shown in FIG. 9 , influenza viruses 1 in the gas introduced into the particle sampling device 10 by the desired air flow (see arrow A in FIG. 9 ) are first charged either positively or negatively by ions 2 released by discharge from the second electrode 24 to which a high voltage is applied. Here, a case in which influenza viruses 1 are positively charged will be described.

[0056] The influenza viruses 1, now in an electrically charged state, move along trajectory 3 due to the electric field (see arrow E in FIG. 9 ) formed between the second electrode 24 and the first electrode 22, 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 captured on the inner surface 66.

[0057] 9 , influenza viruses 1 collected on the inner surface 66 are collected at any timing by liquid 68 stored in the main portion 56 of the first electrode 22. Specifically, influenza viruses 1 adhering to the inner surface 66 of the main portion 56 of the first electrode 22 come into contact with the stored liquid 68, detach from the inner surface 66, and are collected in the liquid 68. The movement (rotation) of the first electrode 22 rotated by the motor 88 and gear 86 makes it possible to wash away the entire surface of the inner surface 66 of the first electrode 22 with the accumulated (stored) liquid 68.

[0058] In addition, when the inner surface 66 of the first electrode 22 has been hydrophilized, a voltage may be applied between the first electrode 22 and the second electrode 24 before rotating the first electrode 22 around the axis B, and the first electrode 22 may be rotated around the axis B with the voltage applied between the first electrode 22 and the second electrode 24.

[0059] The collection operation is performed until the collection operation time set by the user has elapsed while the first electrode 22 is rotating and the voltage is applied to the second electrode 24. After the collection operation time set by the user has elapsed, the rotation of the first electrode 22 and the application of the voltage to the second electrode 24 are stopped, and the collection operation is stopped.

[0060] Next, with reference to Figures 6 and 7, an example of the operation of collecting the liquid 68 during the capture of influenza viruses 1 and after the influenza viruses 1 are collected in the liquid in this embodiment will be described. As shown in Figures 6 and 7, the collection tube 32 is inserted into the guide tube 34 and reaches the lowest point 67 of the inner surface 66 along the collection line 100. The entire amount of the liquid 68 is then collected by operating the collection unit 31. For example, the user operates an arbitrary operation button (not shown) connected to the collection unit 31 to operate the collection unit 31. The collection unit 31 may then collect the liquid 68 stored in the main portion 56 of the first electrode 22.

[0061] Next, the infection risk estimation analysis performed using the collected liquid 68 will be described.

[0062] In the infection risk estimation analysis, a liquid 68 containing influenza viruses 1, which are particles, is obtained as a liquid sample from the tank of the collection machine.

[0063] Next, the removed liquid sample is analyzed using an analytical method capable of measuring the infectivity titer of a virus (for example, an analytical method using cells such as TCID50 evaluation), and the infectivity titer of the virus contained in the liquid sample is quantified.

[0064] Then, based on the quantified infectivity (infectivity of influenza virus 1), the amount of air circulating inside during a certain period of time while the voltage is applied, and the collection performance value specified by the particle sampling method, the infectivity per unit volume of influenza virus 1 contained in the air circulating inside is estimated.

[0065] Finally, the user is notified of the estimated infectivity titer per unit volume of the influenza viruses 1. This allows the user to understand the status of the influenza viruses 1 in the space in which the particle sampling device 10 is installed.

[0066] The extracted liquid sample may also be analyzed using an analytical method capable of measuring the amount of virus (such as an analytical method using PCR (Polymerase Chain Reaction)) to quantify the amount of virus contained in the liquid sample. In other words, the amount of influenza virus 1 contained in the liquid 68 collected by the above-described particle sampling method is quantified.

[0067] Then, based on the quantified virus amount (virus amount of influenza virus 1), the amount of air circulating inside during a certain period of time while the voltage was applied, and the collection performance value specified by the particle sampling method, the virus amount per unit volume of influenza virus 1 contained in the air circulating inside is estimated.

[0068] Finally, the user is notified of the estimated virus quantity per unit volume of the influenza viruses 1. This allows the user to understand the status of the influenza viruses 1 in the space in which the particle sampling device 10 is installed.

[0069] As described above, the particle sampling device 10 according to the embodiment can provide the following effects.

[0070] The following items are independent of the scope of the claims. Although specific descriptions may be provided, they are merely examples and do not limit the scope of the claims.

[0071] (Item 1) A particle sampling device 10 for sampling particles in a liquid, comprising: a cylindrical first electrode 22 having open ends in its axial direction; a second electrode 24 extending in the axial direction of the first electrode 22 and disposed within the first electrode 22 at a distance from an inner surface 66 of the first electrode 22; a duct 12 surrounding the first electrode 22; a first tubular portion 19 connected to one end of the duct 12; a second tubular portion 21 connected to the other end of the duct 12; a voltage application unit 26 that applies a voltage between the first electrode 22 and the second electrode 24; and a drive unit 36 ​​that rotates the first electrode 22; wherein the first tubular portion 19 or the second tubular portion 21 has a through hole 33 that is located above a liquid level 68 a of a liquid 68 stored in a part of the inner surface 66 in the direction around the axis of the first electrode 22, and the through hole 33 is a hole for recovering the liquid 68 through the through hole 33.

[0072] With this configuration, when repeatedly sampling particles and recovering the liquid 68, the liquid 68 can be recovered through the through-holes 33. Therefore, the liquid 68 can be recovered each time using recovery means that is uncontaminated or has been cleaned. As a result, the analysis results of the recovered liquid 68 can be prevented from being affected by contamination caused by the previous recovery operation of the liquid 68, and accurate analysis results can be obtained.

[0073] (Item 2) When viewed from the axial direction, the particle sampling device 10 is configured such that if the straight line passing through the through hole 33 is taken as the recovery line 100, the recovery line 100 intersects with the liquid surface 68a, and if the recovery line 100 passes through the lowest point 67 of the inner surface 66, the recovery line 100 does not intersect with the second electrode 24.

[0074] As a result, the recovery means inserted along the recovery line 100 to the lowest point 67 of the inner surface 66 can come into contact with the liquid 68 and reach the lowest point 67 of the inner surface 66. As a result, almost the entire amount of the liquid 68 can be recovered.

[0075] (Item 3) The particle sampling device 10 has a guide tube 34 in the through-hole 33, and the guide tube 34 fixes the direction of the recovery line 100.

[0076] This allows the recovery means inserted into the guide tube 34 to stably reach the lowest point 67 of the inner surface 66 along the recovery line 100. This makes it possible to more reliably recover almost the entire amount of the liquid 68.

[0077] (Item 4) The first electrode 22 includes a main portion 56, a first inner flange portion 62, and a second inner flange portion 64, wherein the first inner flange portion 62 protrudes radially inward from one axial end of the main portion 56 and is annular around the axis, and the second inner flange portion 64 protrudes radially inward from the other axial end of the main portion 56 and is annular around the axis, and if the innermost portion of the guide tube 34 is the innermost portion 35, the innermost portion 35 is located radially outward from the main portion 56 relative to the tip 65 of the first inner flange portion 62 or the tip 65 of the second inner flange portion 64.

[0078] This results in a configuration in which the guide tube 34 is not inserted inside the first electrode 22. Therefore, the guide tube 34 does not affect the electric field generated between the first electrode 22 and the second electrode 24. This makes it possible to prevent the guide tube 34 from inducing dielectric breakdown or the like between the first electrode 22 and the second electrode 24. As a result, it is possible to efficiently sample particles.

[0079] (Item 5) The recovery device 30 recovers the liquid 68. The recovery device 30 includes a recovery tube 32 and a recovery section 31. The recovery tube 32 can reach the liquid surface 68a via a through-hole 33.

[0080] According to this, the liquid 68 can be collected simply by inserting the recovery device 30 into the through-hole 33 and performing a suction operation, so that the liquid 68 can be easily collected.

[0081] The following provides additional information regarding the embodiments.

[0082] The main portion 56 of the first electrode 22 is not limited to a cylindrical shape. For example, the main portion 56 may be an elliptical cylinder, a polygonal cylinder, or the like.

[0083] The first electrode 22 is not limited to being installed with the axis B of the main portion 56 parallel to the horizontal direction. The first electrode 22 does not have to be installed with the axis B of the main portion 56 parallel to the horizontal direction. For example, the first electrode 22 may be installed with the axis B of the main portion 56 tilted relative to the horizontal direction, as long as the liquid 68 can be stored on a portion of the inner surface 66 in the direction around the axis B of the main portion 56 so that the liquid 68 does not flow out of the main portion 56. In other words, the first electrode 22 is only required to be disposed in an orientation that allows the liquid 68 to be stored on the inner surface 66.

[0084] The guide tube 34 is not limited to a cylindrical shape, and may be, for example, an elliptical cylinder or a polygonal cylinder.

[0085] The collection tube 32 of the collection device 30 is not limited to a cylindrical shape. The collection tube 32 may have any shape that can be inserted into the guide tube 34, and may be, for example, an elliptical cylinder or a polygonal cylinder.

[0086] The through-hole 33 is not limited to being provided in the second cylindrical portion 21. For example, the through-hole 33 may be provided in the first cylindrical portion 19.

[0087] When the tip 65 is located inward of the tip 63, it is preferable that the innermost portion 35 is located outward of the tip 65. In this case, the through hole 33 may be located not only in the second tubular portion 21 but also in the first tubular portion 19. When the tip 63 is located inward of the tip 65, it is preferable that the innermost portion 35 is located outward of the tip 63. In this case, the through hole 33 may be located not only in the first tubular portion 19 but also in the second tubular portion 21. These configurations can prevent air flowing inside the first electrode 22 (air flowing as indicated by arrow A) from directly hitting the guide tube 34. This allows air to pass smoothly inside the first electrode 22. Furthermore, contamination of the guide tube 34 can be prevented.

[0088] The supply unit 28 is not essential. For example, even if the supply unit 28 is not provided, the user may supply the liquid 68 to the inner surface 66 of the first electrode 22 via the through-hole 33.

[0089] The recovery unit 31 of the recovery machine 30 is not limited to being equipped with a pump and a tank. For example, the recovery unit 31 may be a syringe, a dropper, a pipette, or the like.

[0090] The first flange 18 and the second flange 20 are not essential because the effects of the present disclosure can be obtained even without them.

[0091] When viewed along the z direction, the first cylindrical portion 19 and / or the second cylindrical portion 21 may be disposed at a position that does not overlap with the first electrode 22 .

[0092] According to the present disclosure, in a device for sampling fine particles, a recovery technology can be provided that can suppress contamination of the collection liquid caused by the previous operation of recovering the collection liquid when recovering the collection liquid stored inside a cylindrical electrode.

[0093] While the particle sampling device according to the present disclosure has been described above based on the embodiments, the present disclosure is not limited to the embodiments. As long as it does not deviate from the spirit of the present disclosure, various modifications conceivable by a person skilled in the art to the embodiments and configurations constructed by combining components of different examples are also included within the scope of the present disclosure.

[0094] The present disclosure is widely applicable to devices for sampling fine particles such as aerosols from gases such as air.

[0095] DESCRIPTION OF SYMBOLS 1 Influenza virus 2 Ion 3 Trajectory 10 Particle sampling device 12 Duct 14 First bearing seal 16 Second bearing seal 18 First flange 19 First cylindrical portion 20 Second flange 21 Second cylindrical portion 22 First electrode 24 Second electrode 26 Voltage application portion 28 Supply portion 30 Recovery device 31 Recovery portion 32 Recovery tube 33 Through hole 34 Guide tube 35 Innermost portion 36 Drive portion 42 Main body 44 First support portion 46 Second support portion 56 Main portion 58 First outer flange portion 60 Second outer flange portion 62 First inner flange portion 63 Tip 64 Second inner flange portion 65 Tip 66 Inner surface 67 Lowest point 68 Liquid 68a Liquid level 69 Space 70 First support 72 Second support 74 First electric wire 76 Second electric wire 78 Tank 80 Injection unit 86 Gear 88 Motor 90 Control unit 91 Setting unit 100 Recovery line

Claims

1. A particle sampling device for sampling particles in a liquid, comprising: a cylindrical first electrode having both open ends in its axial direction; a second electrode extending in the axial direction of the first electrode and disposed within the first electrode at a distance from the inner surface of the first electrode; a duct surrounding the first electrode; a first cylindrical portion connected to one end of the duct; a second cylindrical portion connected to the other end of the duct; a voltage application unit that applies a voltage between the first electrode and the second electrode; and a drive unit that rotates the first electrode, wherein the first cylindrical portion or the second cylindrical portion has a through hole, the through hole being located above the liquid level of the liquid stored in a portion of the inner surface in the direction around the axis of the first electrode, and the through hole being a hole for recovering the liquid through the through hole.

2. A particle sampling device as described in claim 1, wherein, when viewed from the axial direction, if a straight line passing through the through hole is defined as a recovery line, the recovery line intersects with the liquid surface, and when the recovery line passes through the lowest point of the inner surface, the recovery line does not intersect with the second electrode.

3. The particle sampling device according to claim 2, wherein a guide tube is provided in the through hole, and the guide tube fixes the direction of the recovery line.

4. The particle sampling device described in claim 3, wherein the first electrode includes a main portion, a first inner flange portion, and a second inner flange portion, the first inner flange portion protruding radially inward from one end of the main portion in the axial direction of the main portion and being annular around the axial center, the second inner flange portion protruding radially inward from the other end of the main portion in the axial direction of the main portion and being annular around the axial center, and the innermost part of the guide tube is defined as the innermost part, and the innermost part is located radially outward from the tip of the first inner flange portion or the tip of the second inner flange portion.

5. A particulate sampling device as described in any one of claims 1 to 4, comprising a recovery machine that recovers the liquid, the recovery machine including a recovery tube and a recovery section, and the recovery tube being capable of reaching the liquid surface through the through hole.

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