KR20080105248A - Sampler for ultra-fine particles - Google Patents

Abstract

An ultrafine particle sampler is provided to charge particles included in the air and selectively adjust sizes of ultrafine particles collected using electrical mobility to easily measure the concentration of ultrafine particles in a specific space. An ultrafine particle sampler(100) includes an aerosol electric charging part(120) for charging particles included in the air, an electrostatic classifier(140) for classifying the charged particles using an electrical mobility difference according to sizes of the charged particles, and an impactor(130) for filtering particles having sizes greater than a predetermined size. The internal space of the sampler is defined as an air flow path. The electrostatic classifier forms an electric field in the air flow path such that the electric field acts on the charged particles to separate relatively light particles from relatively heavy particles.

Description

Sampler for ultra-fine particles

1 is a block diagram of an ultrafine particle sampler according to an embodiment of the present invention.

2 is a perspective view of an impactor according to an embodiment of the present invention.

3 is a reference diagram for explaining the principle of operation of the impactor according to an embodiment of the present invention.

Figure 4 is a flow chart for explaining the operation of the ultrafine particle sampler according to an embodiment of the present invention.

5 is a photograph of an ultrafine particle sampler manufactured according to an embodiment of the present invention.

Figure 6 is a photograph of each part of the ultrafine particle sampler manufactured according to an embodiment of the present invention.

7 is a graph showing the results of collecting the actual ultrafine particles using an ultrafine particle sampler according to an embodiment of the present invention.

Description of the main parts of the drawing

100: ultra fine particle sampler

101: air flow path 102: air pump

110: air inlet 120: aerosol charge

121: first high voltage generator 122: first high voltage electrode

130: impactor 131: nozzle plate

131a: nozzle 132: impingement plate

132a: opening 140: electrostatic separator

141: second high voltage generator 142: second high voltage electrode

143: filter means 143a: hepa filter

143b: separation groove 150: ultra-fine particle collection unit

151 filter paper

The present invention relates to an ultra-fine particle sampler, and more particularly, to an ultra-fine particle sampler capable of accurately collecting the ultra-fine particles suspended in the air according to their size and making it easy to carry. .

Ultrafine particles of less than about 100 nm in the air suspended particles are more likely to deposit and reach alveoli in the lungs without being filtered out of the human respiratory tract. The substances are likely to be easily taken up by the cells. These microparticles come from a variety of sources, including diesel vehicles, industrial sites that manufacture nanomaterials.

Therefore, it is necessary to minimize the exposure to the ultrafine particles, and for this purpose, a microfine particle sampler capable of easily collecting the fine particles in the air in a specific space and place and identifying the characteristics thereof is required.

The present invention has been made in order to meet the above requirements, to provide an ultra-fine particle sampler capable of measuring the ultra-fine particle concentration in various places by accurately collecting the ultra-fine particles suspended in the air according to the size and easy to carry. Its purpose is to.

The ultrafine particle sampler according to the present invention for achieving the above object is in the ultrafine particle sampler to selectively collect the ultrafine particles by inhaling air containing particles of various sizes, and serves to charge the particles contained in the air An aerosol charged portion, an electrostatic separator that serves to separate the ultrafine particles by using the difference in electrical mobility according to the size of the charged particles, and the front or rear end of the aerosol charged portion, It comprises an impactor that primarily filters the particles, the inner space of the ultra-fine particle sampler is defined as an air flow path through which the air flows, the aerosol charge portion, the impactor and the electrostatic separator is provided along the air flow path The electrostatic separator is provided with an electrostatic separator An electric field is formed in the space of the air flow path corresponding to the tooth, and the force is applied to each charged particle by the electric field formed to separate the relatively small mass microparticles and the relatively large mass particles. .

The impactor is composed of a combination of a nozzle plate and a collision plate provided at a position spaced downwardly from the nozzle plate, the nozzle plate is provided with a plurality of nozzles through which particles pass and an opening is provided at the edge of the impact plate. The nozzle of the nozzle plate and the opening of the impingement plate are not provided at corresponding positions. At this time, the particles passing through the nozzle of the nozzle plate is bent by 90 degrees by the impingement plate to form a jet streamline, the relatively large mass of particles collide with the impingement plate is collected, the relatively small mass of particles It travels along the jet streamline and is discharged along the opening of the impingement plate. In addition, the surface of the impingement plate is provided with an adhesive film which serves to collect the collided particles, the diameter of the nozzle of the nozzle plate is 0.1 to 1mm.

The electrostatic separator includes a second high voltage generator and a second high voltage electrode, wherein the second high voltage generator is in a state in which an inner wall of the air flow path corresponding to the position of the electrostatic separator is in a ground state. Generates a high voltage at and applies it to the second high voltage electrode to form an electric field in the space of the air flow path corresponding to the position provided in the electrostatic separator. In this case, the second high voltage electrode is provided in the vertical direction at the center of the air flow path, and a voltage of 1 to 3 kV is applied to the second high voltage electrode.

The aerosol charge unit charges the particles using any one of corona discharge, radiation, ultraviolet rays and X-rays, and when the particles are charged using the corona discharge, the aerosol charge unit includes a first high voltage generator and a first high voltage electrode. And an inner wall of the air flow path corresponding to the position where the aerosol charge portion is provided is in a ground state, wherein the first high voltage generator generates a high voltage and is applied to the first high voltage electrode to corona discharge. The particles are charged to the (+) state by inducing. At this time, the first high voltage electrode is provided on the inner wall of the air flow path, the voltage applied to the first high voltage electrode is 4 ~ 6kV.

Due to the electric field formed in the electrostatic separator, relatively small mass microparticles are moved to the inner wall of the air flow path, and relatively large mass particles stay in the central portion of the air flow path. In addition, a filtering means is further provided at a lower end of the electrostatic separator, and the filtering means has a separation groove through which ultra-fine particles moved to the inner wall of the air passage can pass through a portion relatively close to the inner wall of the air passage. And a hepa filter that serves to filter particles larger than the ultrafine particles in the central portion of the filtration means. In addition, the diameter of the separation groove has a proportional relationship with the magnitude of the voltage applied to the second high voltage electrode.

Hereinafter, an ultrafine particle sampler according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 is a configuration diagram of an ultrafine particle sampler according to an embodiment of the present invention, FIG. 2 is a perspective view of an impactor according to an embodiment of the present invention, and FIG. 3 is an operating principle of the impactor according to an embodiment of the present invention. This is a reference diagram for explaining.

First, as shown in FIG. 1, the ultrafine particle sampler 100 according to an embodiment of the present invention has an internal space isolated from an external environment, and the internal space is defined as an air flow path 101. In addition, the air inlet 110 is provided at the top and the ultra-fine particle collecting unit 150 is provided at the lower end of the ultra-fine particles contained in the air along the air passage 101 finally the ultra-fine particle collecting unit 150 Is taken by.

An aerosol charge unit 120, an impactor 130, and an electrostatic separator 140 are provided between the air inlet 110 and the micro fine particle collecting unit 150 to collect the micro fine particles. The aerosol charging unit 120, the impactor 130 and the electrostatic separator 140 is a means for separating the ultra-fine particles of the particles of various sizes contained in the air sucked through the air inlet 110, respectively It plays the following roles:

The aerosol charging unit 120 serves to facilitate the ultrafine particle separation by the electrostatic separator 140 by charging the particles contained in the air sucked through the air inlet 110. To this end, the aerosol charging unit 120 is configured to include a first high voltage generator 121 and the first high voltage electrode rod 122, the first high voltage generator 121 generates a high voltage of 4 ~ 6kV 1 serves to apply to the high voltage electrode 122. When a high voltage is applied to the first high voltage electrode 122, corona discharge is induced to generate (+) ions, and the particles are charged to the (+) state by the (+) ions. At this time, the inner wall of the air flow path 101 corresponding to the aerosol charging unit 120 maintains a ground to induce corona discharge. Here, the first high voltage electrode 122 is preferably provided on the inner wall of the air flow path 101, which is to prevent the ultrafine particles from being lost by the electric field by minimizing contact with the flow of air. Meanwhile, in one embodiment of the present invention, the corona discharge through the first high voltage generator 121 and the first high voltage electrode 122 is proposed as the configuration of the aerosol charging unit 120 to charge the particles. In addition to the discharge, a device for generating radiation, ultraviolet rays, X-rays, or the like may also be used as a means for charging the particles. In addition, the charged state of the particles can also be negative polarity.

The impactor 130 filters the particles having a predetermined size or larger than the ultrafine particles by using the difference of inertia. The impactor 130 includes a nozzle plate 131 and a collision plate 132 in detail. For reference, when the size of the ultrafine particles is defined as 50 to 100 nm, the size of the particles filtered by the impactor 130 may be 500 nm or more.

The nozzle plate 131 has a plurality of nozzles 131a through which particles can pass, as shown in FIG. 2, and the collision plate 132 is provided at a position spaced apart from the nozzle plate 131. The opening 132a of a predetermined shape is provided at one side. The opening 132a of the impingement plate 132 is preferably provided at the outer side of the impingement plate 132, and the nozzles 131a of the nozzle plate 131 are provided at a central portion of the nozzle plate 131 so that the collision is performed. The opening 132a of the plate 132 and the nozzles 131a of the nozzle plate 131 are preferably designed so as not to be provided at corresponding positions. In addition, the diameter of each nozzle 131a is preferably 0.1 to 1 mm.

Meanwhile, the principle of filtering particles having a predetermined size or more by the nozzle plate 131 and the collision plate 132 is as follows. First, the air flowing into and passing through the nozzle 131a of the nozzle plate 131 is made to have a faster flow rate by the nozzle 131a having a smaller size than the environment before the inflow (Bernui's law). Air accelerated by the nozzle 131a at a constant speed hits the collision plate 132 and the air flow is bent at 90 degrees as shown in FIG. 3, and finally, an opening formed at the outer side of the collision plate 132. Is discharged through 132a.

As the flow of air is bent by 90 degrees by the impingement plate 132, the particles contained in the air are also bent by 90 degrees. In this case, the flow of particles is defined as a jet streamline. As the particles flow along the jet streamline and finally exit through the opening 132a of the impingement plate 132, particles of relatively small size move along the jet streamline to the opening 132a of the impingement plate 132. Particles of relatively large size that are discharged may not move along the jet streamline but collide with the collision plate 132, and ultimately, may filter particles of a predetermined size or more through the collision plate 132. Here, the surface of the impingement plate 132 is provided with an adhesive film to collect the particles collided with the impingement plate 132, that is, particles of a predetermined size or more, without moving along the jet streamline.

Particles primarily filtered to a predetermined size or less through the aerosol charge part 120 and the impactor 130 are delivered to the electrostatic separator 140, wherein the electrostatic separator 140 is ultrafine particles among the delivered particles. The role is to finally separate the bay.

The principle of separating the ultrafine particles from the particles passed through the aerosol charging unit 120 and the impactor 130 is to form an electric field in the air flow path 101 corresponding to the electrostatic separation unit 140 and in this state relative Therefore, by using the electrical mobility difference between the large mass particles and the relatively small mass particles to separate the relatively small particles, that is, the ultrafine particles.

To implement this, the electrostatic separator 140 is provided with a second high voltage generator 141 and a second high voltage electrode rod 142. Here, the second high voltage electrode 142 is preferably provided in a direction perpendicular to the central portion of the air flow path 101 in order to uniformly charge the particles, the second high voltage electrode 142 is the first high voltage electrode In contrast, the rod is relatively thick. The second high voltage generator 141 serves to generate a high voltage of 1 to 3 kV and apply it to the second high voltage electrode rod 142. At this time, the particles are charged by the aerosol charging unit 120 and the inner wall of the air flow path 101 corresponding to the electrostatic separation unit 140 is maintained in the ground (ground), the electrostatic An electric field is formed in the air flow path 101 corresponding to the separating unit 140, and a force caused by the electric field is applied to the charged particles, and the greater the mass of the charged particles by Equation 1 below, the smaller the electrical mobility. . Therefore, the particles having a relatively small mass, that is, the microparticles, move toward the inner wall of the air passage 101, and the particles having a relatively large mass remain at the central portion of the air passage 101 to separate the microparticles. Will be.

In addition, the magnitude of the electric field can be controlled by adjusting the magnitude of the voltage as it is proportional to the voltage applied as shown in Equation 2 below, and the magnitude of the electric field ultimately depends on the mobility of the charged particles. By controlling the voltage applied to the second high voltage electrode 142, it is possible to control the size of the ultrafine particles that are moved to the inner wall of the air flow path 101.

<Equation 1>

F = qE = m

(F is the force acting on the charged particles, E is the magnitude of the electric field, m is the mass of the charged particles)

<Formula 2>

E = V / d

The lower end of the air passage 101 corresponding to the electrostatic separator 140 is provided with filtration means 143 for selectively passing only the ultrafine particles moved to the inner wall of the air passage 101. The filtering means 143 includes a HEPA filter 143a for filtering particles larger than the ultrafine particles in the center portion and the air portion in the outer portion, that is, the portion corresponding to the inner wall of the air passage 101. It is provided with a separation groove 143b through which the micro fine particles moved to the inner wall of the flow path 101 can pass. The separation stage 143b may be variously changed and changed according to the size of the ultrafine particles. As described above, the diameter of the separating groove 143b may vary depending on the voltage. The second high voltage electrode 142 may be selectively adjusted according to the voltage applied to the second high voltage electrode 142.

The configuration of the aerosol charging unit 120, the impactor 130, and the electrostatic separation unit 140 provided between the air intake port 110 and the ultrafine particle collection unit 150 has been described above. For reference, in FIG. 1 and related descriptions, the impactor 130 is provided on the lower end of the aerosol charging unit 120, but the impactor 130 may be provided on the upper end of the aerosol charging unit 120. Do. In this case, the impactor 130 filters the particles of a predetermined size or more, and proceeds in an order of charging the filtered particles or more through the aerosol charging unit 120.

Meanwhile, the ultrafine particles filtered by the electrostatic separator 140 are finally collected by the filter paper 151 provided in the ultrafine particle collecting unit 150. For reference, the air pump 102 is preferably controlled so that the flow of air is 2 ~ 5L / min.

In addition, although not shown in the drawing, the filter paper 151 is removed from the ultrafine particle collection unit 150, and an analysis means is provided, such as the mass concentration and the component of the ultrafine particles passing through the ultrafine particle collection unit 150. Properties can be measured. For reference, FIG. 5 is a photograph of an ultrafine particle sampler manufactured according to an embodiment of the present invention, and FIG. 6 is a photograph of each part of an ultrafine particle sampler manufactured according to an embodiment of the present invention. In FIG. 6, the first and second high voltage generators 141 and the like are not included, and the upper portion of the upper portion is the air inlet 110, the aerosol charging unit 120, the impactor 130, and the electrostatic separation unit 140. (4th and 5th parts from the left), the ultra-fine particle collecting unit 150 is listed and the bottom is the first high voltage electrode 122, the collision plate 132, the second high voltage electrode 142, filtering means from the left most 143 is listed.

Referring to the operation of the ultra-fine particle sampler according to an embodiment of the present invention having the configuration as described above are as follows. Figure 4 is a flow chart for explaining the operation of the ultra-fine particle sampler according to an embodiment of the present invention.

First, as shown in FIG. 4, air is sucked into the air inlet 110 by the operation of the air pump 102 (S401), and at this time, the flow rate of the sucked air is preferably 2-5 L / min. Inhaled air, exactly, the particles contained in the air are charged by the aerosol charging unit 120 (S402). The charging of the particles may use corona discharge or radiation, ultraviolet rays, X-rays, or the like.

In this state, the charged particles pass through the nozzle plate 131 and the impingement plate 132 of the impactor 130. Accordingly, particles of a predetermined size or more are first filtered (S403). Specifically, the charged particles are accelerated through the nozzle 131a of the nozzle plate 131 and form a jet streamline by the impingement plate 132. Particles having a relatively large mass cannot move along the jet streamline. Finally, only particles of a predetermined size or less are discharged through the opening 132a of the impingement plate 132. In this case, as described above, the impactor 130 may first pass through the particles sucked through the air inlet 110, and then pass through the aerosol charging unit 120 later.

Particles primarily filtered through the aerosol charging unit 120 and the impactor 130 are delivered to the electrostatic separator 140, and the electrostatic separator 140 is an air flow path corresponding to the electrostatic separator 140. An electric field is applied to the space of 101 to spatially separate particles having a relatively small mass and particles having a large mass (S404). That is, relatively small particles, that is, ultrafine particles, move to the inner wall of the air flow path 101 due to their relatively high electrical mobility, and relatively large particles move to the air flow path 101 because their electrical mobility is relatively small. In the center of the box).

The ultrafine particles thus separated are finally transferred to the ultrafine particle collecting unit 150 via the separation groove 143b of the filtration means 143.

Figure 7 is a graph showing the results of the actual ultrafine particles collected by using the ultrafine particle sampler according to an embodiment of the present invention, it can be seen that the ultrafine particles of various sizes can be selectively collected as shown in FIG. Can be. In FIG. 7, the X axis represents the size of the ultrafine particles and the Y axis represents the sampling probability according to the size of the ultrafine particles. Meanwhile, as described above, the size of the ultrafine particles collected through the adjustment of the voltage applied to the second high voltage electrode 142 may be controlled, and thus the size of the ultrafine particles of FIG. 7 and the sampling probability thereof may be selectively varied. Can be.

The ultrafine particle sampler according to the present invention has the following effects.

By charging the particles contained in the air, and by controlling the size of the ultra-fine particles collected by using the electrical mobility it is possible to easily grasp the characteristics such as the concentration of ultra-fine particles in the various spaces.

Claims (18)

In the ultra-fine particle sampler to selectively collect the ultra-fine particles by inhaling air containing particles of various sizes, An aerosol charging unit serving to charge the particles contained in the air, the electrostatic separator to serve to separate the ultrafine particles by using the electrical mobility difference according to the size of the charged particles in the charged particles and the aerosol It is provided at the front or rear end of the whole comprises an impactor that serves to filter the particles of a predetermined size or more, The inner space of the ultrafine particle sampler is defined as an air flow path through which air flows, and the aerosol charge portion, the impactor, and the electrostatic separator are provided along the air flow path. The electrostatic separator forms an electric field in the space of the air flow path corresponding to the position where the electrostatic separator is provided, and the force is applied to each charged particle by the formed electric field so that a relatively small mass of ultrafine particles and a relatively large mass Ultrafine particle sampler, characterized in that to separate the particles of. The method of claim 1, wherein the impactor is made of a combination of a nozzle plate and a collision plate provided at a position spaced downward from the nozzle plate, The nozzle plate includes a plurality of nozzles through which particles pass, and an opening is formed outside the collision plate, and the nozzle of the nozzle plate and the opening of the collision plate are not provided at corresponding positions. . The method of claim 2, wherein the particles passing through the nozzle of the nozzle plate is bent 90 degrees by the impingement plate to form a jet streamline, the relatively large mass of particles impinge on the impingement plate is collected, the relatively small mass of Particles can move along the jet streamline and be discharged along the opening of the impingement plate. The ultrafine particle sampler of claim 2, wherein an adhesive film is formed on the surface of the impingement plate to collect collided particles. 3. The ultrafine particle sampler according to claim 2, wherein the nozzle has a diameter of 0.1 to 1 mm. The method of claim 1, wherein the electrostatic separator comprises a second high voltage generator and a second high voltage electrode, In the state where the inner wall of the air flow path corresponding to the position provided in the electrostatic separator forms a ground, the second high voltage generator generates a high voltage and applies the second high voltage electrode to the electrostatic separator. An ultrafine particle sampler, characterized in that an electric field can be formed in a space of an air flow path corresponding to a predetermined position. 7. The ultrafine particle sampler according to claim 6, wherein the second high voltage electrode is provided in a direction perpendicular to the central portion of the air passage. 6. The ultrafine particle sampler according to claim 5, wherein a voltage of 1 to 3 kV is applied to the second high voltage electrode. The ultrafine particle sampler of claim 1, wherein the aerosol charge unit charges the particles using any one of corona discharge, radiation, ultraviolet rays, and X-rays. 10. The method of claim 9, wherein in the case of charging the particles using a corona discharge, the aerosol charging unit comprises a first high voltage generator and a first high voltage electrode, In the state where the inner wall of the air flow path corresponding to the position where the aerosol charge part is provided is in a ground state, the first high voltage generator generates a high voltage and applies the first high voltage electrode to the corroded discharge to induce corona discharge. An ultrafine particle sampler, characterized in that it is charged with a single polarity of +) or (-) state. The ultrafine particle sampler according to claim 10, wherein the first high voltage electrode is provided on an inner wall of the air passage. The ultrafine particle sampler according to claim 10, wherein the voltage applied to the first high voltage electrode is 4 to 6 kV. The method of claim 1, wherein the microscopic particles of a relatively small mass is moved to the inner wall of the air flow path by the electric field formed in the electrostatic separator, and the relatively large mass of particles stay in the central portion of the air flow path. Ultra-fine particle sampler. 15. The ultrafine particle sampler according to claim 13, wherein filtration means is further provided at a lower end of the electrostatic separator. 15. The method of claim 14, wherein the filtering means has a separation groove through which the fine particles moved to the inner wall of the air flow passage in a portion relatively close to the inner wall of the air flow passage, the central portion of the filtering means An ultrafine particle sampler, characterized in that the HEPA filter is provided to filter out particles larger than the ultrafine particles. 15. The ultrafine particle sampler of claim 14, wherein a diameter of the separation groove has a proportional relationship with a magnitude of a voltage applied to the second high voltage electrode. 16. The microfine particle sampler according to claim 15, further comprising a filter paper that filters the microparticles having a specific size or more at a lower end of the filtering means. The ultrafine particle sampler according to claim 1, wherein the flow rate of air passing through the air flow path is 2 to 5 L / min.

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