JP2016006391A - Particle detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the discharge by a discharge electrode and improve the efficiency of collecting particles.SOLUTION: A particle detection device comprises: an enclosure having an introduction port and an exhaust port facing the introduction port; exhaust means for venting the air inside the enclosure from the exhaust port; a collection cylinder 190 located inside the enclosure and extending from the introduction port side toward the exhaust port side; a discharge unit, located inside the enclosure, for causing the particles included in the air introduced from the introduction port into the enclosure to be charged with electricity; a collection unit for causing the particles electrically charged by the discharge unit to be adhered to a collection member by an electrostatic force and collecting the adhered particles; and particle detection means for detecting the amount of organism-derived particles that are included in the particles collected by the collection unit. The discharge unit includes a needle electrode 140 that penetrates part of the collection cylinder and has its tip located inside the collection cylinder. The collection cylinder 190 includes an electrically grounded conductor 191 that is provided on the inner circumferential face of the collection cylinder 190 and located apart from the tip of the needle electrode 140.

Description

  The present invention relates to a particle detection device, and more particularly, to a particle detection device that detects biologically derived particles.

  JP-A-2003-337086 (Patent Document 1) is a prior art document that discloses an apparatus for collecting suspended particulate matter in the atmosphere. The airborne particulate matter collection device described in Patent Document 1 is arranged in a collection container, a pump that sucks air into the collection container, and the collection container. A discharge electrode that generates and charges floating particulate matter in the collection container, and a dust collection electrode that draws and collects the suspended particulate matter charged in the collection container by applying a potential difference to the discharge electrode With. This dust collecting electrode is composed of a transparent member having a recess formed on the surface and a transparent electrode film coated on at least the bottom surface of the recess.

JP 2003-337086 A

  When the collection container is charged, stable discharge cannot be performed at the discharge electrode, and the particle collection efficiency is lowered.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a particle detector that can stabilize discharge at a discharge electrode and improve particle collection efficiency.

  A particle detection device according to the present invention is a particle detection device that detects biologically-derived particles, and includes a housing having an inlet and a discharge port facing the introduction port, and exhausts air in the housing from the discharge port. Included in the exhaust means, the collection cylinder located inside the casing and extending from the inlet side toward the outlet, and the air located in the casing and introduced into the casing from the inlet Discharge unit for charging particles, collection unit for collecting particles charged by the discharge unit by electrostatic force attached to the collection member, and biological particles contained in the particles collected by the collection unit Particle detecting means for detecting the amount of The discharge part includes a needle electrode penetrating through a part of the collecting cylinder and having a tip located inside the collecting cylinder. The collecting cylinder includes an electrically grounded conductor that is provided on the inner peripheral surface of the collecting cylinder and is spaced from the tip of the needle electrode.

  In one form of this invention, the conductor is located in the inlet side from the needle-like electrode in the extending direction of the collection tube.

  In one form of this invention, the conductor is located on the opposite side to the part of the collecting tube in the radial direction of the collecting tube.

In one form of this invention, the front-end | tip part of the acicular electrode is extended in the radial direction of the collection cylinder.
In one aspect of the present invention, the particle detecting means is located in the housing and irradiates excitation light toward the particles attached to the collecting member, and is located in the housing and irradiated with the excitation light. A fluorescence detection unit that detects fluorescence emitted from the particles, a heating unit that is positioned so as to be in contact with the collection member and heats the particles attached to the collection member, and fluorescence that is detected from the particles irradiated with the excitation light Calculating means for calculating the amount of biologically-derived particles from the amount whose amount has been changed by heating of the heating unit.

  According to the present invention, the discharge at the discharge electrode can be stabilized and the particle collection efficiency can be improved.

It is a graph which shows the fluorescence intensity of the particle | grains of biological origin before a heating and after a heating. It is a graph which shows the fluorescence intensity of the dust before a heating and after a heating. It is a schematic diagram for demonstrating a collection process. It is a schematic diagram for demonstrating the fluorescence measurement process before a heating. It is a schematic diagram for demonstrating a heating process. It is a schematic diagram for demonstrating the fluorescence measurement process after a heating. It is a graph which shows the correlation with the increase amount of the fluorescence amount by heating, and the density | concentration of the particle | grains of biological origin. It is a perspective view which shows the external appearance of the particle | grain detection apparatus which concerns on Embodiment 1 of this invention. It is the perspective view which looked at the particle | grain detection apparatus of FIG. 8 from another direction. It is a perspective view which shows the state which removed the fan from the particle | grain detection apparatus of FIG. It is a disassembled perspective view which shows the structure of the particle | grain detection apparatus of FIG. It is the fragmentary perspective view which looked at the particle | grain detection apparatus of FIG. 11 from the arrow XII direction. It is a disassembled perspective view which shows the structure of a collection part and a heating part. It is a bottom view which shows the external appearance of a collection part and a heating part. It is a partial top view which shows the connection state of a collection board | substrate and a heater. It is the figure which looked at the collection board | substrate and heater of FIG. 15 from the arrow XVI direction. It is a disassembled perspective view which shows the attachment state of each structure of a particle | grain detection apparatus. It is the figure which looked at the particle | grain detection apparatus of FIG. 17 from the arrow XVIII direction. It is a perspective view which shows the state to which the collection part and the moving mechanism were connected. It is sectional drawing which looked at the state where the collection board | substrate is located in the 1st position from the downward direction of the collection board | substrate. It is sectional drawing which looked at the state where the collection board | substrate is located in the 2nd position from the downward direction of the collection board | substrate. It is sectional drawing which looked at the state where the collection board | substrate is located in the 3rd position from the downward direction of the collection board | substrate. It is sectional drawing which looked at the state where a collection board is located in the 4th position from the lower part of a collection board. It is a flowchart which shows the flow of operation | movement of the particle | grain detection apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the state which has arrange | positioned the collection board | substrate in the 1st position which is a collection position in the particle | grain detection apparatus which concerns on Embodiment 1 of this invention. In Experimental example 1, it is a block diagram which shows the structure of the experimental apparatus which measured the electric potential of the surface of a collection board | substrate. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on the comparative example 2 detected in high humidity conditions. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on Example 2 detected in high humidity conditions. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on the comparative example 2 detected in low humidity conditions. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on Example 2 detected in low humidity conditions. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on the comparative example 3 detected in high-humidity conditions. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on Example 3 detected in high humidity conditions. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on the comparative example 3 detected in low humidity conditions. It is a graph which shows the time-dependent change of the charging voltage of the surface of the collection board | substrate of the particle | grain detection apparatus which concerns on Example 3 detected in low humidity conditions.

  First, a method for detecting biologically derived particles in the particle detection apparatus of the present invention will be described. The biological particles are particles derived from organisms including microorganisms and fungi such as molds and pollen, and do not include dusts such as minerals and refined petroleum products.

  Particles floating in the air are mixed with dusts such as minerals and petroleum refined products and biological particles. In order to measure the amount of biological particles contained in the mixed particles, when the mixed particles are irradiated with ultraviolet light or blue light, the biological particles emit fluorescence. However, the mixed particles include chemical fiber dust that emits fluorescence (hereinafter also referred to as dust) in addition to biologically derived particles. Therefore, the amount of biologically derived particles cannot be measured only by detecting the fluorescence emitted from the mixed particles.

  Therefore, the present inventors utilize the fact that the fluorescence intensity (fluorescence amount) changes when the biological particles are heated, and that the fluorescence intensity does not change even when dust such as chemical fibers is heated. A particle detection method was developed to measure the amount of particles.

  FIG. 1 is a graph showing fluorescence intensity of biological particles before and after heating. FIG. 2 is a graph showing the fluorescence intensity of the dust before and after heating. 1 and 2, the vertical axis represents the fluorescence intensity, and the horizontal axis represents the wavelength of the fluorescent light.

  As shown in FIG. 1, in the biological particles, the amount of fluorescence after heating is remarkably increased in comparison with the amount of fluorescence before heating in a wide wavelength range. On the other hand, as shown in FIG. 2, in the dust, the amount of fluorescence after heating is substantially the same as the amount of fluorescence before heating.

  Therefore, by measuring the amount of fluorescence before heating of the mixed particles and the amount of fluorescence after heating, and obtaining the difference between the amount of fluorescence before heating and the amount of fluorescence after heating, the biological particles contained in the mixed particles The amount of can be calculated.

  Hereinafter, each step of the particle detection method will be described. The particle detection method includes a step of collecting mixed particles, a step of measuring mixed particles before heating, a step of heating mixed particles, a step of measuring mixed particles after heating, and a step of calculating the amount of biological particles. including.

  FIG. 3 is a schematic diagram for explaining the collection process. FIG. 4 is a schematic diagram for explaining the fluorescence measurement process before heating. FIG. 5 is a schematic diagram for explaining the heating step. FIG. 6 is a schematic diagram for explaining the fluorescence measurement process after heating. FIG. 7 is a graph showing the correlation between the amount of increase in fluorescence due to heating and the concentration of biological particles. In FIG. 7, the vertical axis indicates the amount of increase in fluorescence due to heating, and the horizontal axis indicates the concentration of biological particles.

  As shown in FIG. 3, the mixed particles floating in the air are collected on a collection substrate 510 in the collection step. In this step, the collection substrate 510 is disposed to face the needle electrode 530. A DC power source 540 is connected to the collection substrate 510 and the needle electrode 530, and a potential difference is generated between the collection substrate 510 and the needle electrode 530. For example, the positive electrode of the DC power supply 540 is connected to the needle electrode 530, and the negative electrode of the DC power supply 540 is connected to the collection substrate 510.

  By driving the fan 500 positioned below the collection substrate 510, external air is introduced so as to pass through the periphery of the needle electrode 530 toward the collection substrate 510. The mixed particles 600 floating in the air are charged with a positive charge around the needle electrode 530. The collection substrate 510 has a charge opposite to that of the charged mixed particles 600. Therefore, the charged mixed particles 600 are collected by adhering to the surface of the collection substrate 510 by electrostatic force. The mixed particles 600 collected on the collection substrate 510 include biological particles 600A and dust 600B such as chemical fiber dust.

  As shown in FIG. 4, in the fluorescence measurement step before heating, excitation light is irradiated from the light emitting element 550 such as a semiconductor laser toward the mixed particles 600 collected on the collection substrate 510. The fluorescence emitted from the mixed particles 600 irradiated with the excitation light is condensed by the lens 560 and received by the light receiving element 565.

  As shown in FIG. 5, in the heating step, the mixed particles 600 collected on the collection substrate 510 are heated by heating the collection substrate 510 with a heater 520 attached to the lower surface of the collection substrate 510. After heating, the collection substrate 510 is air-cooled.

  As shown in FIG. 6, in the fluorescence measurement step after heating, excitation light is irradiated from the light emitting element 550 toward the mixed particles 600 collected on the collection substrate 510. The fluorescence emitted from the mixed particles 600 irradiated with the excitation light is condensed by the lens 560 and received by the light receiving element 565.

As shown in FIG. 7, based on the relationship between the increase amount ΔF of the fluorescence amount and the biological particle concentration N, the fluorescence measured in the fluorescence measurement step before heating from the fluorescence amount measured in the fluorescence measurement step after heating. From the difference ΔF1 obtained by subtracting the amount, the concentration (particles / m ³ ) of organism-derived particles is calculated. The correlation between the increase amount ΔF and the biological particle concentration N is obtained by conducting an experiment in advance.

  Hereinafter, a particle detection apparatus according to Embodiment 1 of the present invention that detects biologically-derived particles using the above-described particle detection method will be described. In the drawings referred to in the following embodiments, the same or corresponding members are denoted by the same reference numerals and description thereof will not be repeated. For convenience of explanation, the upper and lower expressions are used, but this is based on the referenced drawings and does not limit the configuration of the invention.

(Embodiment 1)
FIG. 8 is a perspective view showing the appearance of the particle detection apparatus according to Embodiment 1 of the present invention. FIG. 9 is a perspective view of the particle detector of FIG. 8 as seen from another direction. FIG. 10 is a perspective view showing a state where the fan is removed from the particle detection apparatus of FIG. FIG. 11 is an exploded perspective view showing the configuration of the particle detection apparatus of FIG. FIG. 12 is a partial perspective view of the particle detection device of FIG. 11 viewed from the direction of arrow XII.

  As shown in FIGS. 8-12, the particle | grain detection apparatus 100 which concerns on Embodiment 1 of this invention is the housing | casing 110, an exhaust means, a discharge part, a collection part, the irradiation part 130, and the fluorescence detection part 160. FIG. And a heating part, a calculation means, a moving mechanism, and a cleaning part. The irradiation unit 130, the fluorescence detection unit 160, the heating unit, and the calculation unit are included in the particle detection unit. The particle detection means detects the amount of biologically-derived particles contained in the particles collected by the collection unit, as will be described later.

  The housing 110 includes a lid portion 111 having an introduction port 111a and a discharge port 112a facing the introduction port 111a, and includes a main body portion 112 that is combined with the lid portion 111 and has a box shape. The housing 110 further includes a rigid substrate 200 fixed on the lid portion 111. A ground electrode 210 is provided on the rigid substrate 200. The ground electrode 210 is electrically connected to a conductor described later by a wiring 192. The wiring 192 is formed from a conductive member such as copper foil or aluminum foil.

  The case 110 has a substantially rectangular parallelepiped shape, and houses a discharge part, a collection part, an irradiation part, a fluorescence detection part, a heating part, a moving mechanism, and a cleaning part. The main body 112 has an opening on the side opposite to the discharge port 112a. The lid portion 111 has a flat plate shape that closes the opening of the main body portion 112. For example, the housing 110 has a size of 60 mm × 50 mm (length and width of the lid portion 111) × 30 mm (height).

  The collection tube 190 is connected to the lid portion 111 so as to be orthogonal to each other. In the casing 110, the collection tube 190 extends in a cylindrical shape toward the main body 112 so as to be continuous with the introduction port 111a. The collection tube 190 is provided so as to surround the tip of a needle electrode 140 described later. The collection tube 190 guides the air containing the mixed particles toward the collection substrate 170 positioned with respect to the needle electrode 140. The housing 110 and the collecting cylinder 190 are made of an electrically insulating material such as an epoxy resin.

  The collection tube 190 includes an electrically grounded conductor 191 provided on the inner peripheral surface of the collection tube 190 and positioned at a distance from the tip of the needle electrode 140. The conductor 191 is connected to the wiring 192 by solder. In the present embodiment, the conductor 191 has a sheet-like shape and is attached to the inner peripheral surface of the collection tube 190. However, the form of the conductor 191 is not limited to the above. For example, a recess is formed on the inner peripheral side of the collection tube 190, and a plate-like conductor may be fitted in the recess. In this case, the surface of the conductor and the inner peripheral surface of the collecting tube 190 may be continuous, or the surface of the conductor may be recessed with respect to the inner peripheral surface of the collecting tube 190.

  In the present embodiment, the conductor 191 is located on the opposite side of the collection cylinder 190 through which the needle electrode 140 penetrates, as will be described later, in the radial direction of the collection cylinder 190. However, the arrangement of the conductor 191 is not limited to the above, and it is only necessary that the conductor 191 be positioned at a distance from the tip of the needle electrode 140 so as to constitute the inner peripheral surface of the collection tube 190.

  The conductor 191 is located closer to the introduction port 111a than the needle electrode 140 in the extending direction of the collection tube 190. That is, the conductor 191 is positioned on the windward side of the needle electrode 140 with respect to the air flow introduced into the housing 110 from the introduction port 111a as described later. The conductor 191 does not overlap with a virtual extension line obtained by extending the needle electrode 140.

  In the present embodiment, the conductor 191 is made of copper, but the material of the conductor 191 is not limited to copper, and may be any material having high electrical conductivity such as aluminum.

  The fan 120, which is an exhaust unit, exhausts the air in the housing 110 from the exhaust port 112a. The fan 120 can be driven to rotate in the forward direction and the reverse direction. By driving the fan 120 in the forward rotation direction, the air inside the casing 110 is discharged to the outside of the casing 110 through the fan 120. By driving the fan 120 in the reverse direction, air outside the housing 110 is introduced into the housing 110 through the fan 120. The fan 120 is attached to the position of the discharge port 112a of the main body 112.

  The discharge unit is located in the housing 110 and charges mixed particles contained in the air introduced into the housing 110 from the introduction port 111a by the exhaust of the fan 120. The discharge part has a high-voltage DC power supply 141 as a power supply part and a needle-like electrode 140 as a discharge electrode. The needle-like electrode 140 extends from the high-voltage DC power source 141, penetrates a part of the collection tube 190 and reaches the inside of the collection tube 190. In the present embodiment, the needle-like electrode 140 penetrates from the outside to the inside of the collecting tube 190 in the vicinity of the center in the extending direction of the collecting tube 190. The tip of the needle electrode 140 extends in the radial direction of the collection tube 190.

  The positive electrode of the high voltage DC power supply 141 is connected to the needle electrode 140. Note that the negative electrode instead of the positive electrode of the high-voltage DC power supply 141 may be connected to the needle electrode 140. The collection substrate 170 is electrically connected to the high-voltage DC power supply 141 and a heater 180 described later, so that a potential difference is generated between the collection substrate 170 and the needle electrode 140.

  The irradiation unit 130 is located in the housing 110 and irradiates excitation light toward the mixed particles attached to the collection substrate 170. The irradiation unit 130 includes a light emitting element 131 as a light source, an element frame 132, a lens frame 133, a condenser lens 134, and a lens holder 135.

  As the light emitting element 131, a semiconductor laser, an LED (Light Emitting Diode) element, or the like is used. The light emitted from the light emitting element 131 may have a wavelength in either the ultraviolet or visible region as long as it excites biological particles to emit fluorescence.

  The fluorescence detection unit 160 is located in the housing 110 and detects fluorescence emitted from the mixed particles irradiated with excitation light. The fluorescence detection unit 160 includes a noise shield 161, an amplifier circuit 162, a light receiving element 163, a light receiving frame 164, a Fresnel lens 165, and a lens presser 166. As the light receiving element 163, a photodiode or an image sensor is used.

  The moving mechanism moves the collection substrate 170. The moving mechanism includes a motor holder 175, a rotation motor 174 as a rotation drive unit, and a motor presser 173. The rotation motor 174 is connected to the rotation base 172 of the collection unit.

  The cleaning unit removes the mixed particles that have undergone the fluorescence detection from the collection substrate 170. The cleaning unit includes a brush 150, a brush press 151, and a brush fixing unit 152. The brush 150 is sandwiched between a brush press 151 and a brush fixing portion 152 and fixed at one end. The cleaning unit is fixed to the lower surface of the high-voltage DC power supply 141.

  The brush 150 is formed from a fiber assembly. The brush 150 is formed from a fiber assembly having conductivity. The brush 150 is made of, for example, carbon fiber. The fiber aggregate forming the brush 150 preferably has a diameter of φ0.05 mm or more and φ0.2 mm or less. By using the conductive brush 150, the charge of the charged mixed particles can be removed.

  FIG. 13 is an exploded perspective view showing configurations of the collection unit and the heating unit. FIG. 14 is a bottom view showing the external appearance of the collection unit and the heating unit. FIG. 15 is a partial plan view showing a connection state between the collection substrate and the heater. 16 is a view of the collection substrate and the heater of FIG. 15 as viewed from the direction of the arrow XVI.

  The collection unit has a collection substrate 170 that is a collection member, and collects the charged mixed particles by attaching them to the collection substrate 170 by electrostatic force. The collection substrate 170 is formed from a glass plate. A conductive transparent film is formed on the surface of the glass plate.

  The collection substrate 170 is not limited to glass, and may be formed of ceramic or metal. A film is not limited to a transparent film, For example, a metal film may be formed. Moreover, when the collection board | substrate 170 is formed from a metal, it is not necessary to form a film on the surface.

  The collection substrate 170 is fixed on the substrate holder 171. The substrate holder 171 is connected to a rotation base 172 connected to the moving mechanism. An arm portion 176 bulges from the rotation base 172. The substrate holder 171, the rotation base 172, and the arm portion 176 are integrally formed of a resin material. The collection unit includes a substrate holder 171, a rotation base 172, and an arm unit 176.

  The collection part has an engagement hole 172a, which is an engaged part engaged with an output shaft 174a of a rotary motor 174, which will be described later, in the rotation base 172. Moreover, the collection part has the collection board | substrate 170 in the position away in radial direction centering | focusing on the engagement hole 172a.

  As shown in FIGS. 13 and 14, the arm portion 176 extends in the radial direction with the engagement hole 172 a of the rotation base 172 as the rotation center. The arm portion 176 is provided at a position shifted in the circumferential direction from the substrate holder 171 around the axis of the shaft portion 172b. The arm portion 176 has a thin arm tip 176a at the tip.

  The heater 180 serving as a heating unit is positioned so as to contact the collection substrate 170 and heats the mixed particles attached to the collection substrate 170. In the present embodiment, the heater 180 is attached to the lower surface of the collection substrate 170.

  The heater 180 is a power supply wiring to the heater 180 and includes a high potential side wiring 181 and a low potential side wiring 182 through which a direct current flows, and a signal line 183 of a temperature sensor built in the heater 180. The high potential side wiring 181, the low potential side wiring 182, and the signal line 183 are connected to one end of a flexible printed wiring board 184 that is a flat wiring that can follow the rotation of the collection board 170.

  The other end of the flexible printed wiring board 184 is pulled out of the housing 110 and connected to a control unit that receives a signal from the temperature sensor and a DC power source. The surface of the flexible printed wiring board 184 is orthogonal to a plane including the radial direction with the engagement hole 172a as the rotation center.

  With this configuration, when the rotary base 172 rotates as shown by the arrow 10 in FIG. 14, the flexible printed wiring board 184 moves and deforms following the rotation, so the high potential side wiring 181 and the low potential side It can suppress that load is applied to the wiring 182 and the signal line 183.

  As shown in FIGS. 15 and 16, the collection substrate 170 is electrically connected to either the high potential side wiring 181 or the low potential side wiring 182. In the present embodiment, the collection substrate 170 is connected to the low potential side wiring 182 in order to charge the collection substrate 170 to a negative charge. When the negative electrode of the high-voltage DC power supply 141 is connected to the needle electrode 140, the collection substrate 170 is connected to the high potential side wiring 181 in order to charge the collection substrate 170 to a positive charge.

  The collection substrate 170 and the heater 180 are bonded by a conductive adhesive 185. When the collection substrate 170 is electrically connected to the low potential side wiring 182 of the heater 180 via the conductive adhesive 185, the collection substrate 170 is charged with a negative charge and between the mixed particles charged with the positive charge. Static electricity is generated.

  However, the collection substrate 170 may be fixed to the ground potential. In this case, the high potential side wiring 181 or the low potential side wiring 182 is fixed to the ground potential, and the collection substrate 170 is connected to the high potential side wiring 181 or the low potential side wiring 182 fixed to the ground potential. Also in this case, the charged mixed particles can be attached to the collection substrate 170 and collected. In this case, an alternating current may be passed through the high potential side wiring 181 and the low potential side wiring 182.

  As the conductive adhesive 185, for example, an epoxy resin adhesive manufactured by adding a noble metal powder to a one-pack type epoxy resin adhesive can be used. In the present embodiment, the collection substrate 170 and the low potential side wiring 182 are electrically connected using the conductive adhesive 185, but may be connected using, for example, solder.

  In the present embodiment, the collection substrate 170 and the low potential side wiring 182 are connected. For example, an electrode connected to the low potential side wiring 182 is provided on the surface of the heater 180, and this electrode and the collection are connected. The substrate 170 may be electrically connected by a conductive adhesive 185.

  As described above, the number of wirings can be reduced by combining the wiring for generating electrostatic force and the wiring for heating the collecting member. As a result, the wiring around the collection substrate 170 can be easily routed, and the occurrence of mixed wiring and disconnection can be suppressed.

  Hereinafter, the attachment state of each component will be described. FIG. 17 is an exploded perspective view showing an attachment state of each component of the particle detection device. FIG. 18 is a view of the particle detection device of FIG. 17 as viewed from the direction of the arrow XVIII.

  As shown in FIGS. 17 and 18, the discharge unit, the irradiation unit 130, the fluorescence detection unit 160, and the cleaning unit are attached to the lid unit 111. In the present embodiment, the moving mechanism is also attached to the lid 111. However, the moving mechanism may be attached to the main body 112. An output shaft 174 a that is an engaging portion that transmits the driving force of the rotary motor 174 protrudes below the rotary motor 174.

  The collecting part is attached to the main body part 112. Since the heater 180 that is a heating unit is attached to the lower surface of the collection substrate 170, the heater 180 is attached to the main body 112 together with the collection unit.

  FIG. 19 is a perspective view illustrating a state in which the collecting unit and the moving mechanism are connected. In FIG. 19, the housing 110 is not shown. By engaging the engagement hole 172a of the rotation base 172 with the output shaft 174a of the rotation motor 174, as shown in FIG. 19, the collection part and the moving mechanism are connected. As the rotation motor 174 is driven, the rotation base 172 rotates (forward rotation, reverse rotation) about the engagement hole 172a.

  Hereinafter, the arrangement of the components of the particle detection device and the position of the collection substrate 170 in plan view will be described.

  FIG. 20 is a cross-sectional view of the state where the collection substrate is located at the first position, as viewed from below the collection substrate. FIG. 21 is a cross-sectional view of the state where the collection substrate is located at the second position, as viewed from below the collection substrate. FIG. 22 is a cross-sectional view of the state where the collection substrate is located at the third position, as viewed from below the collection substrate. FIG. 23 is a cross-sectional view of the state where the collection substrate is located at the fourth position, as viewed from below the collection substrate.

  20-23, in this embodiment, the discharge part, the fluorescence detection part, and the cleaning part are arrange | positioned along with the circumferential direction centering on the axial part 172b of the rotation base 172. As shown in FIG. Specifically, a fluorescence detection unit, a discharge unit, and a cleaning unit are arranged in order counterclockwise. The irradiation unit 130 is disposed adjacent to the fluorescence detection unit.

  The first position is the position of the collection substrate 170 when the charged particles are attached to the collection substrate 170 while charging the mixed particles by the discharge unit. The second position is the position of the collection substrate 170 when the fluorescence is detected by the fluorescence detection unit while irradiating excitation light to the mixed particles attached to the collection substrate 170 by the irradiation unit 130.

  The third position is the position of the collection substrate 170 when the cleaning unit starts removing the mixed particles on the collection substrate 170. The fourth position is the position of the collection substrate 170 when the removal of the mixed particles on the collection substrate 170 by the cleaning unit is completed. A turning range around the shaft portion 172b from the first position to the fourth position is within about 180 °.

  The collection substrate 170 is rotated by driving the rotation motor 174 to move between the first position and the second position. Further, the collection substrate 170 is rotated by driving the rotation motor 174 and moves between the second position and the third position. Further, the collection substrate 170 is rotated by driving the rotation motor 174 to move between the third position and the fourth position.

  As shown in FIGS. 20 to 23, in the main body 112, the proximity sensor 112b and the proximity sensor 112c are arranged on inner walls that are orthogonally adjacent to each other. Each of the proximity sensor 112 b and the proximity sensor 112 c has a pair of terminal portions extending from the inner wall of the main body portion 112 toward the inside of the main body portion 112.

  The collection part is attached to the main body part 112 so that the arm tip part 176a passes between the pair of terminal parts when the shaft part 172b is rotated about the rotation center axis. The proximity sensor 112b and the proximity sensor 112c are sensors that detect the position of the collection substrate 170 by detecting the proximity of the arm tip 176a.

  Hereinafter, the operation of the particle detection apparatus 100 in the present embodiment will be described. FIG. 24 is a flowchart showing an operation flow of the particle detection apparatus according to the present embodiment. In the following description, in FIGS. 20 to 23, clockwise rotation around the shaft portion 172b is referred to as normal rotation direction, and counterclockwise rotation is referred to as reverse direction.

  As shown in FIGS. 20 and 24, first, the collection substrate 170 is disposed at the first position, which is the collection position. In this state, as a collection step, the fan 120 is driven in the forward rotation direction to introduce air into the housing 110 from the introduction port 111a, and the collection substrate 170 is electrically connected to the high-voltage DC power supply 141 and the heater 180. To generate a potential difference between the needle-like electrode 140 and the collection substrate 170, and charge the mixed particles floating in the air to adhere to the surface of the collection substrate 170 and collect them ( S101).

  In this embodiment, since the acicular electrode 140 is used as the discharge electrode, the charged mixed particles are irradiated on the surface of the collection substrate 170 facing the tip of the acicular electrode 140 and irradiated by the irradiation unit 130. It can be attached to a very narrow area corresponding to the area. Thereby, in the fluorescence measurement process of a post process, the fluorescence emitted from the collected mixed particles can be detected efficiently.

  As shown in FIGS. 21 and 24, next, the rotation motor 174 is driven to rotate the rotation base 172 in the forward rotation direction, and the collection substrate 170 is moved to the second position which is the fluorescence detection position (S102).

  Thereafter, as a fluorescence measurement step of the mixed particles before heating, the irradiation unit 130 irradiates the excitation light toward the mixed particles that are attached to the collection substrate 170 and collected, and the fluorescence detection unit irradiates the excitation light. Fluorescence emitted from the mixed particles is received. Thereby, the amount of fluorescence before heating of the mixed particles collected by being attached to the collection substrate 170 is measured (S103).

  As shown in FIGS. 20 and 24, next, the rotation motor 174 is driven to rotate the rotation base 172 in the reverse direction, and the collection substrate 170 is moved from the second position to the first position (S104).

  Next, as a heating process, the mixed particles collected by being attached to the collection substrate 170 are heated by energizing the heater 180 and heating the collection substrate 170 (S105).

  Thereafter, the energization to the heater 180 is stopped, and the collection substrate 170 is cooled (S106). At this time, by driving the fan 120 in the reverse direction, air may be introduced into the housing 110 from the discharge port 112a to promote cooling of the collection substrate 170.

  As shown in FIGS. 21 and 24, next, the rotation motor 174 is driven to rotate the rotation base 172 in the forward rotation direction, and the collection substrate 170 is moved from the first position to the second position (S107).

  Thereafter, as a fluorescence measurement process of the mixed particles after heating, the irradiation unit 130 irradiates excitation light toward the mixed particles that are attached to the collection substrate 170 and collected, and the fluorescence detection unit irradiates excitation light. Fluorescence emitted from the mixed particles is received. Thereby, the amount of fluorescence after heating of the mixed particles collected by being attached to the collection substrate 170 is measured (S108).

  As shown in FIGS. 22 and 24, next, as a cleaning process, the rotation motor 174 is driven to rotate the rotation base 172 in the reverse direction, and the collection substrate 170 is moved from the second position to the third position. Further, the collection base 170 is moved from the third position to the fourth position by rotating the rotation base 172 in the reverse direction. While the collection substrate 170 moves from the third position to the fourth position, the surface of the collection substrate 170 slides with the tip of the brush 150. Thereby, the mixed particles are removed from the collection substrate 170 (S109).

  During the cleaning process, the fan 120 is driven in the forward rotation direction, and the mixed particles removed from the collection substrate 170 are discharged out of the housing 110 from the discharge port 112a. At this time, as the collection substrate 170 approaches the third position from the first position, a range in which the collection substrate 170 and the collection cylinder 190 overlap with each other decreases, and thus the opening area of the collection cylinder 190 increases. Thereby, the mixed particles can be efficiently discharged to the outside of the housing 110. On the other hand, since the opening area of the collection cylinder 190 is reduced by being shielded by the collection substrate 170 during the collection process, it is possible to reduce air introduction loss.

  In this embodiment, since the cleaning process is performed by moving the collection substrate 170 while the cleaning unit is stationary, there is no need to separately provide a moving mechanism for the cleaning unit. For this reason, the manufacturing cost can be reduced by reducing the size of the particle detector 100.

  As shown in FIGS. 20 and 24, the rotation motor 174 is driven to rotate the rotation base 172 in the forward rotation direction, and the collection substrate 170 is moved from the fourth position to the first position (S110). By repeating the above steps S101 to S110, it is possible to continuously detect biological particles.

  The detection of biological particles is measured in the fluorescence measurement process before heating and the fluorescence measurement process after heating by a calculation means such as a CPU (Central Processing Unit) connected to the fluorescence detection unit. This is done by calculating the amount of biologically-derived particles contained in the mixed particles from the difference from the fluorescence amount. In the present embodiment, the calculation means is mounted on the rigid board 200, but the calculation means may be attached to the lid portion 111 inside the casing 110 or arranged outside the casing 110. May be.

  As described above, complicated wiring is performed by electrically connecting the collection substrate 170 to the low-potential-side wiring 182 of the heater 180 and generating an electrostatic force with the charged mixed particles. The mixed particles can be collected on the collection substrate 170 and collected.

  As a result, it is possible to prevent the wiring from being mixed or disconnected due to the rotation of the collection substrate 170. Further, by using the flexible printed wiring board 184, the flexible printed wiring board 184 moves and deforms following the rotation of the rotating base 172, so that a load is applied to the wiring connected to the collection unit and the heating unit. Can be suppressed. Thus, the durability of the particle detector 100 can be improved by reducing the load on the wiring.

  In the present embodiment, the collection position (first position), the fluorescence detection position (second position), and the cleaning position (third to fourth positions) are arranged side by side on the circumference, and the collection substrate 170 is By rotating in the forward rotation direction and the reverse rotation direction, these positions are moved. With this configuration, the particle detection apparatus 100 can be reduced in size.

  In the present embodiment, the heating step of heating the mixed particles collected on the collection substrate 170 is the same position (first position) as the collection step of collecting the particles on the collection substrate 170 and collecting them. By implementing in, it can make the particle | grain detection apparatus 100 small.

  In this embodiment, the engaging portion of the rotary motor 174 is configured by the output shaft 174a and the engaged portion of the rotating base 172 is configured by the engaging hole 172a. You may comprise the to-be-engaged part of the rotation base 172 with an input shaft.

  The particle detection device 100 in the present embodiment may be used as a single device for detecting biological particles, or an air cleaner, an air conditioner, a humidifier, a dehumidifier, a vacuum cleaner, a refrigerator, a television, or the like. It may be incorporated into other household appliances.

  Hereinafter, the operation of the conductor 191 in the particle detection apparatus 100 according to the present embodiment will be described. FIG. 25 is a cross-sectional view illustrating a state in which the collection substrate is disposed at the first position, which is the collection position, in the particle detection device according to the present embodiment. As shown in FIG. 25, in the collection process, while introducing air in the direction indicated by the arrow 10, a potential difference is generated between the needle electrode 140 and the collection substrate 170 to float in the air. The mixed particles are charged.

  If the collection tube 190 is charged to a potential having the same polarity as that of the needle electrode 140 due to continuous discharge of the needle electrode 140, the potential difference around the tip of the needle electrode 140 becomes small. The discharge at the needle electrode 140 becomes unstable. As a result, the charge of the mixed particles becomes insufficient and the collection efficiency of the mixed particles decreases.

  Therefore, in the particle detection device 100 according to the present embodiment, an electrically grounded conductor 191 is provided on the inner peripheral surface of the collection tube 190. Thereby, it can suppress that the collection cylinder 190 charges. As a result, the discharge in the needle electrode 140 can be stabilized and the collection efficiency of mixed particles can be improved.

  As described above, the conductor 191 is located closer to the introduction port 111a than the needle electrode 140 in the extending direction of the collection tube 190. That is, the conductor 191 is positioned on the windward side of the needle electrode 140 with respect to the air flow introduced into the housing 110 from the introduction port 111a. Thereby, it can suppress that the ion generate | occur | produced by the discharge in the acicular electrode 140 lose | disappears by contacting with the conductor 191. As a result, the mixed particles can be sufficiently charged to improve the collection efficiency of the mixed particles.

  As described above, the conductor 191 is located on the opposite side of the radial direction of the collection cylinder 190 with respect to a part of the collection cylinder 190 through which the needle electrode 140 passes. Thereby, the distance between the needle-like electrode 140 and the conductor 191 can be secured, and the occurrence of discharge between the needle-like electrode 140 and the conductor 191 and the damage to the conductor 191 can be suppressed.

  Hereinafter, in the particle detector according to the example provided with the conductor 191 and the particle detector according to the comparative example not provided with the conductor 191, stable discharge when the needle-like electrode 140 is continuously discharged. An experimental example comparing the properties will be described.

(Experiment 1)
FIG. 26 is a block diagram illustrating the configuration of an experimental apparatus that measures the surface potential of the collection substrate in Experimental Example 1. As shown in FIG. 26, in Experimental Example 1, the needle electrode 140 is connected to the negative electrode of the high-voltage DC power source, and the lower surface of the collection substrate 170 is grounded. In the first embodiment, the conductor 191 is connected to the ground electrode 210 of the rigid substrate by the wiring 192.

  In the first embodiment, one terminal 710 of the high voltage probe 700 is in contact with the surface of the collection substrate 170, and the other terminal 720 of the high voltage probe 700 is in contact with the ground electrode 210. In Comparative Example 1, one terminal 710 of the high-pressure probe 700 is in contact with the surface of the collection substrate 170, and the other terminal 720 of the high-pressure probe 700 is in contact with the inner peripheral surface of the collection tube 190. The high voltage probe 700 detects the charged voltage on the surface of the collection substrate by measuring the potential difference between one terminal 710 and the other terminal 720, and outputs the detection result from the output terminal 730 to the storage unit 740.

  In the configuration of the experimental apparatus shown in FIG. 26, negative ions generated by the discharge of the needle electrode 140 are carried by the air flowing in the direction indicated by the arrow 10 and reach the surface of the collection substrate 170. As a result, the surface of the collection substrate 170 is charged so as to have a negative polarity. The high voltage probe 700 detects the charging voltage on the surface of the collection substrate 170.

  In the particle detection apparatus 100 according to the present embodiment, it is possible to suppress the discharge in the needle electrode 140 from becoming unstable due to the influence of the humidity of the air introduced into the housing 110. Hereinafter, in the particle detector according to the example provided with the conductor 191 and the particle detector according to the comparative example not provided with the conductor 191 using the same test apparatus as in the experimental example 1, the needle electrode 140 is used. An experimental example in which the influence of the humidity of the air introduced into the housing 110 on the discharge when the gas is continuously discharged will be described.

(Experimental example 2)
In this experiment, the humidity of the air introduced into the casing 110 is set to one of a high humidity condition of 40% to 50% and a low humidity condition of about 20%, and is continuously performed with a needle electrode. Then, an experiment was conducted to detect the charging voltage on the surface of the collection substrate of Examples and Comparative Examples when discharged. The experiment was performed using a total of four particle detection devices: the particle detection device according to Examples 2 and 3 provided with the conductor 191, and the particle detection device according to Comparative Examples 2 and 3 without the conductor 191. It was.

  FIG. 27 is a graph showing the change over time of the charging voltage on the surface of the collection substrate of the particle detection device according to Comparative Example 2 detected under high humidity conditions. FIG. 28 is a graph showing the change with time of the charging voltage on the surface of the collection substrate of the particle detector according to Example 2 detected under high humidity conditions. FIG. 29 is a graph showing the change over time of the charging voltage on the surface of the collection substrate of the particle detection device according to Comparative Example 2 detected under low humidity conditions. FIG. 30 is a graph showing the change over time in the charging voltage on the surface of the collection substrate of the particle detector according to Example 2 detected under low humidity conditions.

  FIG. 31 is a graph showing the change with time of the charging voltage of the surface of the collection substrate of the particle detection device according to Comparative Example 3 detected under high humidity conditions. FIG. 32 is a graph showing the change over time of the charging voltage on the surface of the collection substrate of the particle detection apparatus according to Example 3 detected under high humidity conditions. FIG. 33 is a graph showing the change with time of the charging voltage on the surface of the collection substrate of the particle detection device according to Comparative Example 3, which was detected under low humidity conditions. FIG. 34 is a graph showing the change over time in the charging voltage on the surface of the collection substrate of the particle detection device according to Example 3 detected under low humidity conditions. 27 to 34, the vertical axis represents the charging voltage on the surface of the collection substrate, and the horizontal axis represents the elapsed time.

  As shown in FIGS. 27, 28, 31, and 32, the voltage drop after the first discharge occurs in the charging voltage on the surface of the collection substrate 170 of the particle detector according to Comparative Examples 2 and 3 under high humidity conditions. It was big. In addition, the charging voltage on the surface of the collection substrate 170 of the particle detector according to Comparative Example 3 increased each time the number of discharges increased. On the other hand, the charging voltage on the surface of the collection substrate 170 of the particle detector according to Examples 2 and 3 under high humidity conditions was stable.

  As shown in FIGS. 29, 30, 33, and 34, the voltage fluctuation after the fifth discharge is large in the charging voltage of the surface of the collection substrate 170 of the particle detector according to Comparative Examples 2 and 3 under low humidity conditions. It was. Moreover, the charging voltage of the surface of the collection substrate 170 of the particle | grain detection apparatus which concerns on the comparative example 3 rose compared with the 4th time from the 5th discharge. On the other hand, the charging voltage on the surface of the collection substrate 170 of the particle detection device according to Examples 2 and 3 under the high humidity condition is equal to the charging voltage of the surface of the collection substrate 170 of the particle detection device according to Comparative Examples 2 and 3. It was more stable than that.

  As shown in FIGS. 27 to 34, it was confirmed that the charging voltage on the surface of the collection substrate 170 was more stable under high humidity conditions than under low humidity conditions. It was confirmed that the charging voltage on the surface of the collection substrate 170 was smaller in fluctuation in the particle detection device according to Examples 2 and 3 than in the particle detection device according to Comparative Examples 2 and 3. Therefore, it was confirmed that by providing the conductor 191, the discharge of the needle-like electrode 140 can be stabilized and the mixed particles can be sufficiently charged, and as a result, the collection efficiency of the mixed particles can be improved.

  Hereinafter, the particle | grain detection apparatus which concerns on Embodiment 2 of this invention is demonstrated. In the following description of the embodiment, only differences from the particle detection device 100 according to the first embodiment will be described, and description of the same configuration as the particle detection device 100 according to the first embodiment will not be repeated.

(Embodiment 2)
The collection substrate 170 in the particle detector according to the second embodiment of the present invention is made of metal. A film is not formed on the surface of the collection substrate 170. Therefore, the process of forming a film on the surface of the collection substrate 170 can be reduced.

  Hereinafter, the particle | grain detection apparatus which concerns on Embodiment 3 of this invention is demonstrated. In the following description of the embodiment, only differences from the particle detection device 100 according to the first embodiment will be described, and description of the same configuration as the particle detection device 100 according to the first embodiment will not be repeated.

(Embodiment 3)
The collection substrate 170 in the particle detection device according to the third embodiment of the present invention is made of ceramic. A metal film is formed on the surface of the collection substrate 170.

  Hereinafter, the particle | grain detection apparatus which concerns on Embodiment 4 of this invention is demonstrated. In the following description of the embodiment, only differences from the particle detection device 100 according to the first embodiment will be described, and description of the same configuration as the particle detection device 100 according to the first embodiment will not be repeated.

(Embodiment 4)
The collection substrate 170 in the particle detection apparatus according to the fourth embodiment of the present invention is fixed to the ground potential. Specifically, the high potential side wiring 181 or the low potential side wiring 182 is fixed to the ground potential, and the collection substrate 170 is connected to the high potential side wiring 181 or the low potential side wiring 182 fixed to the ground potential. Also in this embodiment, the charged mixed particles can be attached to the collection substrate 170 and collected. An alternating current may be passed through the high potential side wiring 181 and the low potential side wiring 182.

  Hereinafter, the particle | grain detection apparatus which concerns on Embodiment 5 of this invention is demonstrated. In the following description of the embodiment, only differences from the particle detection device 100 according to the first embodiment will be described, and description of the same configuration as the particle detection device 100 according to the first embodiment will not be repeated.

(Embodiment 5)
In the particle detection apparatus according to the fifth embodiment of the present invention, an electrode connected to the low potential side wiring 182 is provided on the surface of the heater 180, and the electrode and the collection substrate 170 are electrically connected by the conductive adhesive 185. It is connected to the.

  Hereinafter, the particle | grain detection apparatus which concerns on Embodiment 6 of this invention is demonstrated. In the following description of the embodiment, only differences from the particle detection device 100 according to the first embodiment will be described, and description of the same configuration as the particle detection device 100 according to the first embodiment will not be repeated.

(Embodiment 6)
In the particle detection apparatus according to Embodiment 6 of the present invention, a recess is formed on the inner peripheral side of the collection tube 190, and a plate-like conductor 191 is fitted in the recess. The surface of the conductor 191 and the inner peripheral surface of the collecting cylinder 190 may be continuous, or the surface of the conductor 191 may be recessed with respect to the inner peripheral surface of the collecting cylinder 190.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 particle detector, 110 housing, 111 lid, 111a inlet, 112 body, 112a outlet, 112b, 112c proximity sensor, 120,500 fan, 130 irradiator, 131,550 light emitting element, 132 element frame, 133 Lens frame, 134 Condensing lens, 135, 166 Lens holder, 140, 530 Needle electrode, 141 High voltage DC power supply, 150 brush, 151 Brush holder, 152 Brush fixing part, 160 Fluorescence detection part, 161 Noise shield, 162 Amplification Circuit, 163, 565 Light receiving element, 164 Light receiving frame, 165 Fresnel lens, 170, 510 Collection substrate, 171 Substrate holder, 172 Rotating base, 172a Engagement hole, 172b Shaft, 173 Motor holder, 174 Rotating motor, 174a Output shaft, 175 motor holder, 176 arm portion, 176a arm tip, 180, 520 heater, 181 high potential side wiring, 182 low potential side wiring, 183 signal line, 184 flexible printed wiring board, 185 conductive adhesive, 190 Collection cylinder, 200 rigid substrate, 210 ground electrode, 540 DC power supply, 560 lens, 600 mixed particles, 600A biological particle, 600B dust, 700 high-pressure probe, 710, 720 terminal, 730 output terminal, 740 storage unit.

Claims (5)

A particle detection device for detecting biological particles,
A housing having an inlet and an outlet facing the inlet;
Exhaust means for exhausting air in the housing from the exhaust port;
A collection cylinder located inside the housing and extending from the inlet side toward the outlet side;
A discharge unit that is located in the casing and charges particles contained in the air introduced into the casing from the inlet;
A collection unit for collecting particles charged by the discharge unit by electrostatic force attached to the collection member; and
A particle detecting means for detecting the amount of biological particles contained in the particles collected by the collecting unit;
The discharge part includes a needle-like electrode that penetrates a part of the collection tube and has a tip portion located inside the collection tube,
The said collection cylinder is a particle | grain detection apparatus provided in the inner peripheral surface of the said collection cylinder, and the electrically earth | grounded conductor located at intervals with the said front-end | tip part of the said acicular electrode.   The particle detector according to claim 1, wherein the conductor is located closer to the introduction port than the needle-like electrode in the extending direction of the collection tube.   The particle detector according to claim 1, wherein the conductor is located on an opposite side of the collecting tube in the radial direction of the collecting tube.   4. The particle detection device according to claim 1, wherein the tip portion of the needle-like electrode extends in a radial direction of the collecting cylinder. 5. The particle detection means includes
An irradiation unit that is located in the housing and irradiates excitation light toward the particles attached to the collection member;
A fluorescence detection unit that is located within the housing and detects fluorescence emitted from the particles irradiated with the excitation light;
A heating unit that is positioned so as to contact the collecting member and that heats particles adhering to the collecting member;
The calculation means which calculates the quantity of the particle | grains derived from a living organism | raw_food from the quantity which the fluorescence amount detected from the particle | grains irradiated with the said excitation light changed by the heating of the said heating part is included. The particle | grain detection apparatus as described in.

Images