JP2021053550A - Electrostatic atomizer - Google Patents

Abstract

To provide an electrostatic atomizer that can atomize mist into a space efficiently.SOLUTION: An electrostatic atomizer 100 comprises: a first electrode 20 provided with a through-hole 22; a nozzle 10 arranged through the through-hole 22 and having a discharge port through which liquid L is discharged provided at an end part thereof; a second electrode 30 that pairs with the first electrode 20 and atomizes liquid L by applying voltages to the liquid L; a third electrode 40 which surrounds the discharge port when viewed from a direction in which the liquid L is discharged through the discharge port; and a voltage application part 50 that applies voltages to first electrode 20, the second electrode 30 and the third electrode 40.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electrostatic atomizer.

Conventionally, a device for generating mist used for sterilization, deodorization, etc. is known. The device for generating mist disclosed in Patent Document 1 includes equipotential line adjusting electrodes made of a conductive material that adjusts the state of the equipotential curve appearing around the nozzle. The equipotential line adjusting electrode draws a gentler curve at least a part of the equipotential curve with respect to the state of the equipotential curve that appears on the front side of the nozzle when the equipotential line adjusting electrode is not arranged. It is an auxiliary electrode shaped to have a potential curve. Further, the equipotential line adjusting electrode is arranged near the outer periphery of the tip of the nozzle, and the equipotential line adjusting electrode has the same potential as the spray portion that generates mist. According to this, the spray range of the mist in which the liquid discharged from the nozzle is atomized can be easily controlled.

Japanese Unexamined Patent Publication No. 2017-087124

A device that generates this type of mist is required to efficiently spray the mist into the space.

The present invention provides an electrostatic atomizer capable of efficiently spraying mist into a space.

The electrostatic atomizer according to one aspect of the present invention includes a first electrode provided with a through hole, and a nozzle arranged through the through hole and having a discharge port for discharging liquid at an end. The second electrode, which is paired with the first electrode and atomizes the liquid by applying a voltage to the liquid, surrounds the discharge port when viewed from the direction in which the liquid is discharged from the discharge port. A third electrode, the first electrode, the second electrode, and a voltage application unit for applying a voltage to the third electrode are provided.

According to the present invention, it is possible to provide an electrostatic atomizer capable of efficiently spraying mist into a space.

FIG. 1 is a schematic perspective view showing a configuration of an electrostatic atomizer according to an embodiment. FIG. 2 is a cross-sectional view of the electrostatic atomizer according to the embodiment in line II-II of FIG. FIG. 3 is a cross-sectional view of a nozzle included in the electrostatic atomizer according to the embodiment, which shows an enlarged area surrounded by line III in FIG. FIG. 4 is a graph showing the ratio of the electric field strength in the X-axis direction to the total electric field strength with respect to the position near the nozzle provided in the electrostatic atomizer. FIG. 5 is a diagram for explaining the conditions of the electrostatic atomizer when the graph shown in FIG. 4 is measured. FIG. 6 is a cross-sectional view showing an electrostatic atomizer according to a modified example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that all of the embodiments described below show a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement and connection forms of the components, steps, the order of steps, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Therefore, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept of the present invention will be described as arbitrary components.

Further, each figure is a schematic view and is not necessarily exactly illustrated. Therefore, for example, the scales and the like do not always match in each figure. Further, in each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description may be omitted or simplified.

Further, in the present specification, sterilization refers to, for example, fungi such as Staphylococcus aureus and Staphylococcus epidermidis, Escherichia coli. (E. coli), Pseudomonas sp. (Pseudomonas aeruginosa), Klebsiella sp. Bacteria such as (Klebsiella pneumoniae), Cladosporium. sp. It means that fungi including molds such as (black mold) and Aspergillus (black aspergillus) and / or viruses such as norovirus are decomposed to reduce the total number of bacteria and the like, and it also means sterilization or sterilization. Including. The fungi, bacteria, fungi, viruses, etc. that are the targets of the above sterilization are examples, and are not limited.

Further, in the present specification and the drawings, the X-axis, the Y-axis, and the Z-axis indicate the three axes of the three-dimensional Cartesian coordinate system. In each embodiment, the Z-axis direction is the vertical direction or the front, and the direction perpendicular to the Z-axis (the direction parallel to the XY plane) is the horizontal direction. The positive direction of the Z axis is vertically above.

(Embodiment)
[Constitution]
First, the configuration of the electrostatic atomizer according to the embodiment will be described with reference to FIGS. 1 to 3.

FIG. 1 is a schematic cross-sectional view showing the configuration of the electrostatic atomizer 100 according to the embodiment. FIG. 2 is a cross-sectional view of the electrostatic atomizer 100 according to the embodiment in line II-II of FIG. FIG. 3 is a cross-sectional view of a nozzle 10 included in the electrostatic atomizer 100 according to the embodiment, showing an enlarged region surrounded by line III in FIG.

The electrostatic atomizer 100 includes a container 200, a supply unit 300, a liquid feeding tube 310, a nozzle 10, a first electrode 20, a second electrode 30, a third electrode 40, and a voltage application unit 50. , And a controller 60.

In addition, in FIG. 1 and FIG. 2, the controller 60 is represented as a functional block. The controller 60 is realized by, for example, a microcomputer (microcontroller) or the like, and is arranged inside an outer shell housing (not shown) of the electrostatic atomizer 100. The controller 60 may be attached to the outside of the container 200, for example.

The electrostatic atomizing device 100 is a spraying device that mistizes a liquid L and ejects a mist M having a planktonic property floating in the atmosphere. For example, the electrostatic atomizer 100 has a bactericidal effect or a sterilizing effect by applying a high voltage to the liquid L to generate an electrostatic force and then finely dividing the liquid L into a mist by the generated electrostatic force. It is a device that generates mist M.

The mist M is one of a plurality of liquid particles in which the liquid L constitutes a mist-ized mist. The electrostatic atomizer 100 is used, for example, in a sterilizer, a sterilizer, or the like.

For example, when the liquid L contains a fragrance component, the electrostatic atomizer 100 is an aroma generator that generates a mist M containing the fragrance component.

The electrostatic atomizer 100 sends the liquid L contained in the container 200 to the nozzle 10 by the supply unit 300, thereby guiding the liquid L to the tip (end 11) of the nozzle 10 and to the end 11. Innumerable mists M in which the liquid L is made into a mist are ejected from the discharge port 13 which is the provided opening. In the present embodiment, the liquid L contained in the container 200 is fed by the supply unit 300 to the end portion 11 of the nozzle 10 via the liquid supply tube 310 and the second electrode 30.

The voltage application unit 50 ejects a mist-like liquid L (that is, innumerable mists M) from the discharge port 13 of the nozzle 10 by applying a high voltage between the first electrode 20 and the second electrode 30. To do. Here, the high voltage is, for example, about 5 kV when the ground potential (0 V) is used as a reference, but is not particularly limited. The voltage of the first electrode 20 may be positive or negative with respect to the ground potential. In the present embodiment, the voltage application unit 50 applies 0 V to the first electrode 20 and 5 kV to the second electrode 30.

Inside the nozzle 10, a flow path for guiding the liquid L in the container 200 to the discharge port 13 is formed. The liquid L discharged from the discharge port 13 through the flow path changes its shape due to the electric field to form a tailor cone. Mist M is generated by miniaturizing the liquid L at the tip L1 of the tailor cone.

Although one nozzle 10 is shown in FIG. 1, the number of nozzles 10 included in the electrostatic atomizer 100 is not particularly limited, and may be two or three or more. You may.

The mist M generated at the end portion 11 of the nozzle 10 is discharged toward the first electrode 20. In order to discharge the mist M in front of the first electrode 20, a through hole 22 is provided in the flat plate portion 21 of the first electrode 20 at a position corresponding to the front surface of the nozzle 10. Specifically, the first electrode 20 has a through hole 22 at a position through which the atomized liquid L (that is, mist M) passes. As a result, the mist M is discharged in front of the first electrode 20 through the through hole 22. The “forward” is the direction in which the mist M is discharged, and is the direction opposite to the nozzle 10 with respect to the first electrode 20. In the present embodiment, "forward" is the Z-axis positive direction.

The mist M is, for example, fine liquid particles having a diameter of nm order or μm order, and has a planktonic property suspended in the atmosphere. For example, the outer diameter of the mist M is about several tens of μm. The outer diameter of the mist M is preferably 10 μm or less. Further, more preferably, the diameter of the liquid particles constituting the mist M is 10 nm or more and 3 μm or less.

The mist M is, for example, a liquid particle that exerts a predetermined function (efficacy). The mist M is, for example, a liquid particle containing a fragrance component having a function of generating a fragrance when it comes into contact with the atmosphere, or a liquid particle having a function of sterilizing an object such as a bacterium when it comes into contact with the object. is there.

Hereinafter, the details of each component included in the electrostatic atomizer 100 will be described.

<Nozzle>
The nozzle 10 is a tubular nozzle for discharging the liquid L contained in the container 200. A discharge port 13 is provided at the end 11 of the nozzle 10. The liquid L is discharged from the discharge port 13 of the nozzle 10 via the flow path formed inside the nozzle 10. The nozzle 10 is connected to the second electrode 30 so that the liquid L can flow.

The nozzle 10 is connected to the container 200 and discharges the liquid L contained in the container 200 to the outside of the container 200. Specifically, the nozzle 10 projects from the second electrode 30 connected to the liquid feeding tube 310 connected to the inside of the container 200 so as to penetrate through the through hole 22 formed in the first electrode 20. Further, the nozzle 10 has an opening at the rear end (that is, the container 200 side) and has a flow path from the opening to the discharge port 13. As a result, the nozzle 10 is connected to the container 200 via the liquid feeding tube 310 and the second electrode 30 so that the liquid L can flow.

At least one of the inner diameter and the outer diameter of the nozzle 10 may be gradually reduced from the rear end toward the front end. For example, the discharge port 13 on the front end side may be smaller than the opening on the rear end side, and the shape of the flow path connecting these openings may be a truncated cone shape.

Further, the nozzle 10 is arranged so as to penetrate through the through hole 22. Specifically, the nozzle 10 has an axial direction (in the present embodiment, a Z-axis direction) about the direction in which the liquid L is sprayed, that is, a direction orthogonal to the longitudinal direction of the nozzle 10. When viewed from above (in the present embodiment, when the XZ plane is viewed), it has a portion (for example, the body of the nozzle 10) that overlaps with the first electrode 20. In other words, the first electrode 20 is arranged so as to surround the nozzle 10. In the present embodiment, the first electrode 20 is arranged so as to surround the third electrode 40 which is arranged so as to surround the nozzle 10.

The nozzle 10 may have a portion that overlaps when the XZ plane is viewed. For example, when the nozzle 10 is viewed on the XZ plane, the upper surface of the flat plate portion 21 of the first electrode 20 (the surface on the positive direction side of the Z axis) and the upper surface of the end portion 11 of the nozzle 10 are flush with each other. Is located in. Alternatively, for example, the nozzle 10 has a portion that overlaps with the first electrode 20 and a portion that does not overlap with the first electrode 20 (for example, the end portion 11) when the XZ plane is viewed. In other words, the end portion 11 of the nozzle 10 is located in front of the first electrode 20 (that is, the generation direction of the mist M or the discharge direction of the liquid L discharged from the discharge port 13) when the XZ plane is viewed. To do. That is, "the nozzle 10 is arranged through the through hole 22" means that (i) the upper surface of the flat plate portion 21 of the first electrode 20 and the upper surface of the end portion 11 of the nozzle 10 when viewed from the XZ direction. The nozzles 10 are arranged so as to be flush with each other, and (ii) the end portion 11 of the nozzle 10 in which the nozzle 10 completely passes through the through hole 22 and the discharge port 13 is formed is the first. It means that it is located in front of the electrode 20.

The rear end of the nozzle 10 is connected to a second electrode 30 formed in a tubular shape.

The nozzle 10 preferably has a height ratio to the outer diameter (hereinafter referred to as an aspect ratio) of 4 or more. The length of the nozzle 10 is, for example, 2 mm or more. The outer diameter of the nozzle 10 is, for example, 0.35 mm. The larger the aspect ratio of the nozzle 10, the easier it is for the electric field to concentrate on the end 11 of the nozzle 10. Therefore, the aspect ratio of the nozzle 10 may be, for example, 6 or more.

Here, as the material of the nozzle 10, a non-conductive (in other words, insulating) material is adopted for the outer surface 12 of the end portion 11 of the nozzle 10. The material used for the portion other than the outer surface 12 of the nozzle 10 is not particularly limited, but may be formed by using, for example, a conductive metal material such as stainless steel. The outer surface 12 of the end portion 11 of the nozzle 10 is, for example, an upper surface of the nozzle 10 on the Z-axis positive direction side and a side surface located on the Z-axis positive direction side of the third electrode 40 when viewed from the XZ plane. ..

Further, for example, as the material of the nozzle 10, a liquid-repellent material is adopted for the outer surface 12 of the nozzle 10. For example, the nozzle 10 is made by subjecting the outer surface 12 of the conductive material to a predetermined surface treatment such as a treatment for forming an uneven shape or a treatment with a fluorine-based chemical, so that the outer surface 12 is not formed. It may have conductivity.

For example, by adopting a material for the nozzle 10 in which the outer surface 12 is non-conductive and the other parts other than the outer surface 12 are conductive, the nozzle 10 is paired with the first electrode 20. It can be an electrode. That is, a second electrode paired with the first electrode 20 may be formed on at least a part of the nozzle 10. The second electrode is paired with the first electrode 20, and a voltage is applied to the liquid L discharged from the nozzle 10 to generate mist M. In this case, the electrostatic atomizer 100 does not have to include the second electrode 30.

In this embodiment, a non-conductive material is used for the entire nozzle 10. More specifically, a liquid-repellent material is used for the entire nozzle 10. The degree of liquid repellency is not particularly limited. The material used for the nozzle 10 is, for example, a material having a contact angle larger than 90 ° with respect to the liquid L. Further, the material used for the nozzle 10 is, for example, a material having a contact angle larger than 120 ° with respect to the liquid L. Further, the material used for the nozzle 10 is, for example, a material having a contact angle larger than 150 ° with respect to the liquid L.

The evaluation of the liquid repellency of the material used for the nozzle 10 is not necessarily the evaluation of the liquid repellency to the liquid L, but may be the evaluation of the liquid repellency to water. For example, the material used for the nozzle 10 is, for example, a material having a contact angle larger than 90 ° with respect to water. The material used for the nozzle 10 is, for example, a material having a contact angle larger than 120 ° with respect to water. The material used for the nozzle 10 is, for example, a material having a contact angle larger than 150 ° with respect to water.

Examples of the material having liquid repellency include a material containing a fluororesin. The fluororesin is not particularly limited as long as it has a fluorine atom in at least a part of the polymer repeating units. Examples of the fluororesin include polytetrafluoroethylene (PTFE) and perfluoroalkoxy alkane resin (PFA).

<1st electrode>
The first electrode 20 is a reference electrode that is outside the container 200 and is arranged so as to surround the discharge port 13. In the present embodiment, the first electrode 20 is arranged so as to surround the nozzle 10 and the third electrode 40.

The first electrode 20 is an electrode paired with the second electrode 30, and when a voltage is applied between the first electrode 20 and the second electrode 30, the liquid L is discharged from the end 11 of the nozzle 10 to form a mist. To do. The first electrode 20 is arranged so as to be parallel to the electrode plate 41, for example. Specifically, the rear surface of the first electrode 20 is parallel to the upper surface (the surface on the positive direction side of the Z axis) of the flat plate portion of the electrode plate 41.

The first electrode 20 has conductivity and is formed of, for example, a metal material such as stainless steel. The first electrode 20 may be formed by using a material having acid resistance, alkali resistance, or both of these properties.

The first electrode is provided with a through hole 22. Specifically, the first electrode 20 has a flat plate portion 21, and the flat plate portion 21 has a through hole 22 at the center in a plan view. In other words, a through hole 22 is formed in the center of the flat plate portion 21. The flat plate portion 21 has conductivity and is electrically connected to the voltage applying portion 50. The plate thickness of the flat plate portion 21 is substantially uniform.

The through hole 22 penetrates the flat plate portion 21 in the plate thickness direction (that is, the front-rear direction). Further, the through hole 22 is provided for passing the mist-ized liquid L, that is, the mist M, which is ejected from the discharge port 13. The shape of the through hole 22 is a flat columnar shape. The shape of the opening of the through hole 22 does not have to be circular, and may be square, rectangular, oval, or the like.

The opening diameter of the through hole 22 is not particularly limited, but is, for example, 6.5 mm. Further, the mist M is discharged from the nozzle 10 in the positive direction of the Z axis. Further, the first electrode 20 is located in a direction opposite to the direction in which the mist M is discharged from the nozzle 10 (the Z-axis positive direction) with respect to the end portion 11 of the nozzle 10. Therefore, the mist M is suppressed from adhering to the first electrode 20. The through hole 22 and the end portion 11 of the nozzle 10 are separated from each other by, for example, 3 mm in the Z-axis direction.

<Second electrode>
The second electrode 30 is paired with the first electrode 20 and is an electrode for applying a voltage to the liquid L. The second electrode 30 has conductivity and is formed of, for example, a metal material such as stainless steel. The second electrode 30 may be formed by using a material having acid resistance, alkali resistance, or both of these properties.

In the present embodiment, the second electrode 30 is formed in a tubular shape, and a flow path through which the liquid L flows is formed inside. One end of the flow path is connected to the nozzle 10. The other end of the flow path is connected to the liquid feeding tube 310.

<Third electrode>
The third electrode 40 is an auxiliary electrode surrounding the discharge port 13. Specifically, the third electrode 40 surrounds the discharge port 13 when viewed from the direction in which the liquid L is discharged from the discharge port 13 (in the present embodiment, the Z-axis positive direction). More specifically, the third electrode 40 is arranged so as to surround the vicinity of the end portion 11 having the discharge port 13. In the present embodiment, the third electrode 40 has a tubular shape in which the nozzle 10 is arranged inside.

The third electrode 40 has conductivity and is formed of, for example, a metal material such as stainless steel. The third electrode 40 may be formed by using a material having acid resistance, alkali resistance, or both of these properties. In the present embodiment, the third electrode 40 is formed integrally with the electrode plate 41, and surrounds the discharge port 13 formed at the end portion 11 of the nozzle 10 without contacting the nozzle 10. By forming a gap between the third electrode 40 and the nozzle 10, for example, when the liquid L adheres to the outer surface 12, the liquid L adhering to the gap flows. Therefore, it is possible to prevent the liquid L from remaining between the nozzle 10 and the third electrode 40 and adversely affecting the electric field formed around the end portion 11 of the nozzle 10.

The third electrode 40 may be formed in contact with the nozzle 10.

Further, in the present embodiment, the end portion 11 of the nozzle and the end portion of the third electrode 40 on the first electrode 20 side (that is, the end portion on the positive direction side of the Z axis) are separated by 0.5 mm in the Z axis direction. ing. The end of the third electrode 40 on the first electrode 20 side may be located on the negative side of the Z axis with respect to the end portion 11 of the nozzle, or may be flush with each other.

The outer diameter of the third electrode 40 is, for example, 1.49 mm. The inner diameter of the third electrode 40 is, for example, 1.11 mm.

The electrode plate 41 is a conductive plate that is electrically connected to the voltage application unit 50 and the second electrode 30. The electrode plate 41 is made of, for example, a metal material. The electrostatic atomizer 100 does not have to include the electrode plate 41. In this case, the voltage application unit 50 is directly connected to, for example, the third electrode 40.

<Voltage application part>
The voltage application unit 50 applies a predetermined voltage between the liquid L and the first electrode 20. Specifically, the voltage application unit 50 is electrically connected to the first electrode 20 and the second electrode 30 via metal wiring or the like, and has a predetermined potential difference between the first electrode 20 and the second electrode 30. Apply the potential so that

For example, the first electrode 20 is grounded, and the voltage application unit 50 applies a ground potential to the first electrode 20. The voltage application unit 50 applies a predetermined voltage between the first electrode 20 and the liquid L by applying a potential to the second electrode 30. The second electrode 30 may have a ground potential.

The predetermined voltage applied by the voltage application unit 50 is, for example, a DC voltage of 3.5 kV or more and 10 kV or less. Alternatively, the predetermined voltage may be 4.5 kV or more and 8.5 kV or less. The predetermined voltage may be a pulse voltage, a pulsating voltage, or an AC voltage. In the present embodiment, the voltage application unit 50 applies a voltage of 5.0 kV to the second electrode 30 with respect to the first electrode 20 as a predetermined voltage.

Specifically, the voltage application unit 50 is realized by a power supply circuit including a converter and the like. For example, the voltage application unit 50 generates a predetermined voltage based on the electric power received from an external power source (not shown) such as a commercial power source, and applies the generated voltage between the first electrode 20 and the second electrode 30. Apply a voltage to the liquid L.

Further, the voltage application unit 50 applies a voltage to the third electrode 40.

The voltage application unit 50 has the first electrode 20 and the second electrode so that the potential difference between the first electrode 20 and the third electrode 40 is equal to or greater than the potential difference between the first electrode 20 and the second electrode 30. A voltage is applied to 30 and the third electrode 40.

More specifically, the voltage application unit 50 increases the potential difference between the first electrode 20 and the third electrode 40 with respect to the potential difference between the first electrode 20 and the second electrode 30. , A voltage is applied to the second electrode 30 and the third electrode 40.

Further, for example, the second electrode 30 and the third electrode 40 may have different polarities, but in the present embodiment, the voltage application unit 50 has the second electrode 30 and the third electrode 40 with respect to the first electrode 20. A voltage is applied to the first electrode 20, the second electrode 30, and the third electrode 40 so that the polarities are the same.

In the present embodiment, the voltage application unit 50 applies a voltage of 5.4 kV to the third electrode 40 with respect to the first electrode 20.

<Controller>
The controller 60 is a control device that controls the overall operation of the electrostatic atomizer 100. Specifically, the controller 60 controls the operations of the voltage application unit 50 and the supply unit 300. For example, the controller 60 controls the voltage application unit 50 to control the timing of applying a voltage between the first electrode 20, the second electrode 30, and the third electrode 40, the magnitude of the voltage, and the like. To do.

The supply unit 300 and the voltage application unit 50 are suitably controlled by the controller 60, so that the liquid L discharged from the nozzle 10 forms a clean tailor cone. By forming a tailor cone of an appropriate shape, the electrostatic atomizer 100 can generate a mist M of a desired size and amount.

The controller 60 is realized by, for example, a microprocessor or the like. Specifically, the controller 60 is realized by a non-volatile memory in which the program is stored, a volatile memory which is a temporary storage area for executing the program, an input / output port, a processor for executing the program, and the like. The controller 60 may be realized by a dedicated electronic circuit that executes each operation.

The controller 60 may control the voltage application unit 50 and the supply unit 300 as long as it can control the voltage application unit 50 and the supply unit 300, and may control the voltage application unit 50 and the supply unit 300 by transmitting a wireless signal. It may be connected to the supply unit 300 by a control line or the like.

<Container>
The container 200 is a container for containing the liquid L. The liquid L is, for example, an oily liquid containing a fragrance component when the electrostatic atomizer 100 is an aroma generator. Further, for example, when the electrostatic atomizing device 100 is a sterilizing device, the liquid L is an aqueous liquid containing a sterilizing component such as hypochlorous acid. When the liquid L is mist-ized by electrostatic atomization as in the present embodiment, the liquid L may be water.

The container 200 is formed by using a metal material such as stainless steel, but may be formed by using a resin material. Further, the container 200 may be formed by using a material having acid resistance, alkali resistance, or both of these properties.

The shape of the container 200 is, for example, a columnar shape with an open upper surface, but is not limited to this. The shape of the container 200 may be a cube or a rectangular parallelepiped, or may be a flat tray. The open upper surface of the container 200 is covered with a lid provided through the liquid feeding tube 310.

<Supply section>
The supply unit 300 sends the liquid L in the container 200 to the nozzle 10 via the liquid feeding tube 310 and the second electrode 30. For example, the supply unit 300 is a pump that sends the liquid L to the nozzle 10.

The liquid feeding tube 310 may be directly attached to a faucet or the like of a water supply. In this case, the electrostatic atomizer 100 does not have to include the container 200 and the supply unit 300. Further, depending on the size of the flow path formed in each of the liquid feeding tube 310, the second electrode 30, and the nozzle 10, the liquid L in the container 200 is guided to the end 11 of the nozzle 10 by the capillary phenomenon. be able to. In this case, the electrostatic atomizer 100 does not have to include the supply unit 300.

[Example]
Subsequently, the experimental results of the inventors will be described in detail with reference to FIGS. 4 and 5.

FIG. 4 is a graph showing the ratio of the electric field strength in the X-axis direction to the total electric field strength with respect to the position near the nozzle 10 included in the electrostatic atomizer. FIG. 5 is a diagram for explaining the conditions of the electrostatic atomizer when the graph shown in FIG. 4 is measured.

In the experiments conducted by the inventors below, the electrostatic atomizer according to the comparative example does not include the third electrode 40, unlike the electrostatic atomizer 100 according to the embodiment. Further, the nozzle included in the electrostatic atomizer according to the comparative example is entirely made of a metal material, unlike the nozzle 10 provided in the electrostatic atomizer 100 according to the embodiment. On the other hand, the nozzle 10 provided in the electrostatic atomizer 100 according to the embodiment (Examples 1 and 2 described below) is entirely formed of a liquid-repellent resin. The other configurations of the electrostatic atomizer according to the comparative example are the same as those of the electrostatic atomizer 100 according to the embodiment.

Further, in the first embodiment shown in FIG. 4, a voltage of 5 kV is applied to the third electrode 40 with respect to the first electrode 20 (0 V) by the voltage applying unit 50. Further, in the second embodiment shown in FIG. 4, a voltage of 5.4 kV is applied to the third electrode 40 with respect to the first electrode 20 (0 V) by the voltage applying unit 50.

Further, in Comparative Example, Example 1, and Example 2, the liquid L (more specifically, the second electrode 30) is charged with 5 kV with respect to the first electrode 20 (0 V) by the voltage application unit 50. A voltage is applied.

Further, in Examples 1 and 2, as shown in FIG. 5, the nozzle 10 and the third electrode 40 are in contact with each other.

Further, in Comparative Example, Example 1, and Example 2, the liquid L discharged from the nozzle 10 is simulated as a hemisphere instead of a tailor cone.

Further, in FIG. 4, on the vertical axis, the electric field strength with respect to the position in the X-axis direction at a position 0.5 mm away from the outer surface 12 on the Z-axis positive direction side of the end portion 11 of the nozzle 10 in the Z-axis positive direction (hereinafter referred to as The electric field strength Ex) is shown. Further, in FIG. 4, the horizontal axis shows the position of the tip L1 of the liquid L in the X-axis direction shown in FIG. 5, and the center of the through hole 22 is set to X = 0.

Further, in FIG. 4, the inner diameter (radius) of the through hole 22 is set to X = 3.25 mm.

As shown in FIG. 4, the electric field strength Ex is smaller when the third electrode 40 is provided than when the third electrode 40 is not provided.

By providing the third electrode 40 in this way, the ratio of the electric field strength Ex in the vicinity of the tip L1 can be reduced. In other words, by providing the third electrode 40, the electric field strength in the positive direction of the Z axis near the tip L1 (hereinafter, also referred to as electric field strength Ez) can be increased. According to this, the mist M can be easily sprayed in the positive direction of the Z axis. Therefore, it is possible to suppress the spraying of mist M on the first electrode 20.

Further, as shown in FIG. 4, the electric field strength Ex becomes smaller when the third electrode 40 with respect to the first electrode 20 is applied with a potential larger than that of the second electrode 30 with respect to the first electrode 20.

In this way, by applying a potential larger than that of the second electrode 30 to the first electrode 20 of the third electrode 40 with respect to the first electrode 20, the ratio of the electric field strength Ex in the vicinity of the tip L1 can be further reduced. In other words, by applying a larger potential to the third electrode 40, the electric field strength Ez in the vicinity of the tip L1 can be increased. According to this, the mist M can be more easily sprayed in the positive direction of the Z axis. Therefore, the spraying of mist M on the first electrode 20 can be further suppressed.

[Effects, etc.]
As described above, in the electrostatic atomizer 100 according to the embodiment, the first electrode 20 provided with the through hole 22 and the discharge port 13 arranged through the through hole 22 and discharging the liquid L are provided. The second electrode 30 which is paired with the nozzle 10 provided at the end 11 and the first electrode 20 and atomizes the liquid L by applying a voltage to the liquid L, and the liquid L are discharged from the discharge port 13. It includes a third electrode 40 that surrounds the discharge port 13 when viewed from the direction, a first electrode 20, a second electrode 30, and a voltage application unit 50 that applies a voltage to the third electrode 40.

In the conventional electrostatic atomizer, the first electrode 20 is arranged at a position facing the discharge port 13, and the mist M that has passed through the through hole 22 is discharged into the space. Here, the mist M atomized by electrostatic atomization is charged. The mist M moves along the direction of the electric field formed between the first electrode 20 and the second electrode 30 (more specifically, the liquid L located at the discharge port 13). Further, the mist Ms repel each other and are released into the space. As a result, in the conventional electrostatic atomizer, the mist M is likely to adhere to the first electrode 20 arranged to face the discharge port 13, and the amount of the mist M spreading in the space is likely to be reduced. Therefore, in the electrostatic atomizing device 100, the electrostatic atomizing device 100 is arranged so as to penetrate the nozzle 10 through hole 22 so as to surround the periphery of the nozzle 10 rather than the position facing the discharge port 13, that is, surround the discharge port 13. The first electrode 20 is arranged so as to do so. According to such a configuration, since the first electrode 20 is not arranged at a position facing the discharge port 13, it is possible to prevent the mist M from adhering to the first electrode 20. As described above, according to the electrostatic atomizer 100, the mist M can be efficiently discharged into the space.

Further, for example, the voltage application unit 50 makes the potential difference between the first electrode 20 and the third electrode 40 equal to or greater than the potential difference between the first electrode 20 and the second electrode 30. , A voltage is applied to the second electrode 30 and the third electrode 40.

According to such a configuration, by applying a voltage of the second electrode 30 or more to the third electrode 40, even when the non-conductive nozzle 10 is used, the liquid L discharged from the nozzle 10 is used as the tailor cone. Can be easily formed. As a result, according to the electrostatic atomizer 100, the mist M can be sprayed stably.

Further, for example, the voltage application unit 50 increases the potential difference between the first electrode 20 and the third electrode 40 as compared with the potential difference between the first electrode 20 and the second electrode 30. A voltage is applied to the second electrode 30 and the third electrode 40.

According to such a configuration, it is possible to suppress the height of the tailor cone formed by the liquid L discharged from the nozzle 10 from being unnecessarily increased. Mist M is generated by tearing the tip of the tailor cone each time the tailor cone vibrates in the height direction. If the tailor cone is too high, such vibrations tend to be unstable, and the particle size of mist M may become too large. If the particle size of the mist M is too large, there is a problem that it is difficult for the mist M to cover a wide range in the space. Therefore, by applying a voltage larger than that of the second electrode 30 to the third electrode 40, it is possible to prevent the height of the tailor cone from being unnecessarily increased, so that the particle size of the mist M becomes too large. Can be suppressed.

Further, for example, in the voltage application unit 50, the first electrode 20, the second electrode 30, and the third electrode are arranged so that the second electrode 30 and the third electrode 40 have the same polarity with respect to the first electrode 20. A voltage is applied to 40.

According to such a configuration, it is possible to prevent the mist M from being attracted to the third electrode 40. Therefore, the mist M can be sprayed more efficiently into the space.

Further, for example, the outer surface 12 of the end portion 11 of the nozzle 10 has non-conductive property.

According to such a configuration, by using the non-conductive nozzle 10, the end portion 11, more specifically, the outer surface 12 of the end portion 11 is less likely to get wet. Therefore, it is possible to easily form a tailor cone with the liquid L discharged from the nozzle 10. As a result, according to the electrostatic atomizer 100, the mist M can be sprayed stably.

Further, for example, the outer surface 12 of the end portion 11 of the nozzle 10 has liquid repellency.

According to such a configuration, the end portion 11 of the nozzle 10, more specifically, the outer surface 12 of the end portion 11 can be more difficult to get wet.

(Modification example)
In the above embodiment, the voltage application unit 50 applies a voltage to the first electrode 20 so that the first electrode 20 is 0V.

In the voltage application section, the first electrode 20, the second electrode 30, and the third electrode 40 have the same polarity with respect to the ground potential so that the first electrode 20, the second electrode 30, and the third electrode 40 have the same polarity. A voltage may be applied to 40. That is, the first electrode 20 does not have to be 0V.

FIG. 6 is a cross-sectional view showing an electrostatic atomizer 100a according to a modified example. Note that FIG. 6 is a diagram showing a cross section corresponding to the cross section taken along line II-II shown in FIG.

As shown in FIG. 6, the electrostatic atomizer 100a according to the modified example has the electrostatic atomizer 100 according to the embodiment in the first electrode 20, the second electrode 30, and the third electrode 40. The applied voltage is different.

For example, in the voltage application unit 50a included in the electrostatic atomizer 100a according to the modified example, the first electrode 20 is set to 1 kV, the second electrode 30 is set to 6.0 kV, and the third electrode 40 is set to 6.4 kV. , A voltage is applied to the first electrode 20, the second electrode 30, and the third electrode 40.

As described above, the electrostatic atomizer 100a according to the modified example includes a voltage application unit 50a different from the configuration provided by the electrostatic atomizer 100 according to the embodiment. For example, the electrostatic atomizer 100a has a first electrode 20 having a through hole 22, a nozzle 10 arranged through the through hole 22 and having a discharge port 13 for discharging the liquid L at an end portion 11, and a first electrode. The second electrode 30, which is paired with the first electrode 20 and atomizes the liquid L by applying a voltage to the liquid L, the third electrode 40 surrounding the discharge port 13, the first electrode 20, the second electrode 30, and the like. A voltage application unit 50a for applying a voltage to the third electrode 40 is provided. The voltage application unit 50a includes the first electrode 20, the second electrode 30, and the third electrode 40 so that the first electrode 20, the second electrode 30, and the third electrode 40 have the same polarity with respect to the ground potential (0V). , A voltage is applied to the third electrode 40.

For example, when potentials are applied to the first electrode 20, the second electrode 30, and the third electrode 40, it is considered to be 0 V at the point at infinity when viewed from these electrodes. Therefore, an electric field is likely to be formed in the direction in which the mist M is sprayed (in the present embodiment, the Z-axis positive direction) with respect to the space in which the mist M is sprayed. Therefore, according to such a configuration, the mist M can be sprayed more efficiently into the space.

(Other embodiments)
Although the electrostatic atomizer according to the present invention has been described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment.

For example, in the above embodiment, the nozzle 10 is arranged in the upper part of the container 200, but the present invention is not limited to this. For example, the nozzle 10 may project downward, laterally, or diagonally with respect to the container 200. That is, the spraying direction of the mist M by the electrostatic atomizer 100 according to the present invention is not limited to the upper direction, but may be downward, lateral or oblique.

Further, for example, the first electrode 20 does not have to be a flat electrode, and may be, for example, a smoothly curved electrode plate. The through hole 22 may penetrate the electrode plate in the thickness direction, or may penetrate the flat plate portion 21 in the protruding direction of the nozzle 10.

Further, for example, the controller 60 may further include a time measuring unit for measuring time such as an RTC (Real Time Clock). For example, the controller 60 may generate the mist M at a predetermined time.

Further, in the above embodiment, all or a part of the components such as the controller 60 may be configured by dedicated hardware, or may be realized by executing a software program suitable for each component. May be good. Each component may be realized by a program execution unit such as a CPU (Central Processing Unit) or a processor reading and executing a software program recorded on a recording medium such as an HDD (Hard Disk Drive) or a semiconductor memory. Good.

Further, the component such as the controller 60 may be composed of one or a plurality of electronic circuits. The one or more electronic circuits may be general-purpose circuits or dedicated circuits, respectively.

The one or more electronic circuits may include, for example, a semiconductor device, an IC (Integrated Circuit), an LSI (Large Scale Integration), or the like. The IC or LSI may be integrated on one chip or may be integrated on a plurality of chips. Although it is called an IC or LSI here, the name changes depending on the degree of integration, and it may be called a system LSI, a VLSI (Very Large Scale Integration), or a ULSI (Ultra Large Scale Integration). Further, an FPGA (Field Programmable Gate Array) programmed after manufacturing the LSI can also be used for the same purpose.

In addition, general or specific aspects of the present invention may be realized by a system, an apparatus, a method, an integrated circuit or a computer program. Alternatively, it may be realized by a computer-readable non-temporary recording medium such as an optical disk, an HDD, or a semiconductor memory in which the computer program is stored. Further, it may be realized by any combination of a system, an apparatus, a method, an integrated circuit, a computer program and a recording medium.

In addition, it is realized by arbitrarily combining the components and functions in each embodiment within the range obtained by applying various modifications to each embodiment and the gist of the present invention. Forms are also included in the present invention.

10 Nozzle 11 End 12 Outer surface 13 Discharge port 20 1st electrode 22 Through hole 30 2nd electrode 40 3rd electrode 50, 50a Voltage application part 100, 100a Electrostatic atomizer L Liquid M mist

Claims (7)

The first electrode provided with a through hole and
A nozzle that is arranged through the through hole and has a discharge port at the end for discharging a liquid.
A second electrode that is paired with the first electrode and atomizes the liquid by applying a voltage to the liquid.
A third electrode that surrounds the discharge port when viewed from the direction in which the liquid is discharged from the discharge port,
An electrostatic atomizer comprising the first electrode, the second electrode, and a voltage application unit for applying a voltage to the third electrode. The voltage application unit has the first electrode and the second electrode so that the potential difference between the first electrode and the third electrode is equal to or greater than the potential difference between the first electrode and the second electrode. The electrostatic atomizer according to claim 1, wherein a voltage is applied to the electrodes and the third electrode. The voltage application unit has the first electrode and the second electrode so that the potential difference between the first electrode and the third electrode is larger than the potential difference between the first electrode and the second electrode. The electrostatic atomizer according to claim 1 or 2, wherein a voltage is applied to the third electrode. The voltage application unit applies a voltage to the first electrode, the second electrode, and the third electrode so that the second electrode and the third electrode have the same polarity with respect to the first electrode. The electrostatic atomizer according to any one of claims 1 to 3 to be applied. The voltage applying portion includes the first electrode, the second electrode, and the first electrode so that the first electrode, the second electrode, and the third electrode have the same polarity with respect to the ground potential. 3. The electrostatic atomizer according to any one of claims 1 to 4, wherein a voltage is applied to the electrodes. The electrostatic atomizer according to any one of claims 1 to 5, wherein the outer surface of the end portion of the nozzle has non-conductive properties. The electrostatic atomizer according to any one of claims 1 to 6, wherein the outer surface of the end portion of the nozzle has liquid repellency.

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