JP2008183483A - Electrostatic atomizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic atomizer which generates a strong electric field in a large range between a counter electrode and a discharge electrode and increases the degree of concentration of electric field to the distal end of the discharge electrode. <P>SOLUTION: The electrostatic atomization device, which is provided with the discharge electrode 1, the counter electrode 2 located apart from the distance to the discharge electrode 1, a liquid supply means 3 to supply the liquid to the discharge electrode 1 and a high-voltage application means 4 to apply high voltage between the discharge electrode 1 and the counter electrode 2, and applies high voltage to the liquid retained by the discharge electrode 1 to discharge the generated charged particulate, is characterized that the cross-sectional configuration of the inner face 2b directed to the discharge electrode 1 of the counter electrode 2 is made the circular arc configuration as the center of the distal end 1a of the discharge electrode 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrostatic atomizer that generates a charged fine particle liquid, and more particularly to a technique for efficiently generating a charged fine particle liquid.

  Conventionally, a discharge electrode, a counter electrode positioned at a distance from the discharge electrode, a liquid supply means for supplying a liquid to the discharge electrode, and a high voltage applying means for applying a high voltage between the discharge electrode and the counter electrode There is known an electrostatic atomization apparatus including the above (see Patent Document 1). In this electrostatic atomizer, an electric field is generated between the counter electrode and the discharge electrode by high voltage applying means, and negative charges are concentrated on the liquid held by the discharge electrode, so that the liquid is split and scattered (so-called Rayleigh). An electrostatic atomization phenomenon that repeats splitting is generated, and a nanometer-sized charged fine particle liquid containing active species (radicals) is generated by this electrostatic atomization phenomenon. The charged fine particle liquid produced here is released into a space outside the apparatus by being put on an ion wind, and exhibits a high moisturizing effect, a deodorizing effect, an inactivating effect of allergen substances such as mites and pollen, and the like.

As shown in FIG. 8, the counter electrode 2 of the conventional electrostatic atomizer is formed in a ring shape having a discharge hole 2 a in the center, and the discharge hole 2 a is opposed to the tip end portion 1 a of the discharge electrode 1. I am letting. Therefore, the electric field generated between the inner surface 2b of the counter electrode 2 and the distal end portion 1a of the discharge electrode 1 by the high voltage applying unit 4 is particularly an emission hole having the shortest distance d with respect to the distal end portion 1a of the discharge electrode 1. 2a is strongly generated only in a narrow range between the peripheral portion of the discharge electrode 1 and the distal end portion 1a of the discharge electrode 1, and the concentration of electric field on the distal end portion 1a of the discharge electrode 1 is low. It was difficult to generate a charged fine particle liquid.
JP 2005-131549 A

  The present invention has been invented in view of the above problems, and generates a strong electric field within a wide range between the counter electrode and the discharge electrode, thereby increasing the concentration of the electric field on the tip of the discharge electrode. An object of the present invention is to provide an electrostatic atomizer capable of efficiently generating a charged fine particle liquid.

  In order to solve the above problems, the present invention is directed to the discharge electrode 1, the counter electrode 2 positioned at a distance from the discharge electrode 1, the liquid supply means 3 for supplying a liquid to the discharge electrode 2, and the discharge electrode 1. In an electrostatic atomizer that includes a high voltage applying means 4 that applies a high voltage between the electrodes 2 and that discharges a charged fine particle liquid generated by applying a high voltage to the liquid held by the discharge electrode 2, The cross-sectional shape of at least a part of the inner surface 2b facing the discharge electrode 1 side of the counter electrode 2 is centered on the tip portion 1a of the discharge electrode 1, and the shortest distance d from the tip portion 1a of the discharge electrode 1 to the counter electrode 2 is defined. It is assumed that it is formed along an arc line drawn as a radius.

  In this way, the entire arc line portion formed so as to surround at least the distal end portion 1a of the discharge electrode 1 in the inner surface 2b of the counter electrode 2 is the shortest distance d from the distal end portion 1a of the discharge electrode 1. A strong electric field is generated in a wide range between the arc line portion of the counter electrode 2 and the distal end portion 1a of the discharge electrode 1. Thereby, the concentration degree of the electric field with respect to the tip portion 1a of the discharge electrode 1 is increased, and it becomes possible to efficiently concentrate the electric charge on the liquid held in the discharge electrode 1 and generate the charged fine particle liquid.

  In the electrostatic atomizer having the above configuration, at least a part of the inner surface 2b of the counter electrode 2 facing the discharge electrode 1 side is centered on the tip portion 1a of the discharge electrode 1, and the tip of the discharge electrode 1 is placed. It is preferable that it is formed along a spherical surface that draws the shortest distance d from the portion 1a to the counter electrode 2 as a radius. By doing so, a strong electric field is generated within a wide three-dimensional range formed between the inner surface 2b of the counter electrode 2 and the tip 1a of the discharge electrode 1. As a result, the concentration of the electric field on the tip 1a of the discharge electrode 1 is further increased, and the charged fine particle liquid can be generated by more efficiently concentrating charges on the liquid held in the discharge electrode 1.

  Furthermore, at least a part of the inner surface 2b of the counter electrode 2 facing the discharge electrode 1 side is centered on the tip portion 1a of the discharge electrode 1, and the shortest distance d from the tip portion 1a of the discharge electrode 1 to the counter electrode 2 is set. A hemispherical surface having a radius is preferable. In this way, a stronger electric field is generated within a wide three-dimensional range formed between the inner surface 2b of the counter electrode 2 and the tip end portion 1a of the discharge electrode 1, whereby the discharge electrode The charged fine particle liquid can be generated by more efficiently concentrating the electric charge on the liquid held at 1.

  The counter electrode 2 preferably has a plurality of discharge holes 2a. By doing in this way, the charged fine particle liquid discharge | released toward the counter electrode 2 from the discharge electrode 1 can be sent out out of an apparatus efficiently.

  The counter electrode 2 is preferably provided with a convex curved surface 30 for preventing discharge at the end of the inner surface 2b facing the discharge electrode 1 side. In general, when the discharge electrode 1 and the counter electrode 2 are close to each other, discharge tends to occur at the end of the inner surface 2b facing the discharge electrode 1 side of the counter electrode 2. The positive ions generated by this discharge act to neutralize the charged fine particle liquid having the opposite polarity. Therefore, by providing the convex curved surface 30 to prevent concentration of the electric field and to prevent discharge, the charged fine particle liquid can be stabilized. Can be supplied to.

  The invention according to claim 1 generates a strong electric field within a wide range between the counter electrode and the discharge electrode, and increases the concentration of the electric field with respect to the tip of the discharge electrode, thereby efficiently charging the charged fine particle liquid. There is an effect that it can be generated.

  In addition to the effect of the invention according to claim 1, the invention according to claim 2 is powerful within a three-dimensional wide range formed between the inner surface of the counter electrode and the tip of the discharge electrode. Since an electric field is generated and the concentration of the electric field at the tip of the discharge electrode is further increased, it becomes possible to more efficiently concentrate the charge on the liquid held in the discharge electrode and generate the charged fine particle liquid. There is an effect.

  In addition to the effect of the invention according to claim 2, the invention according to claim 3 is more powerful within a wide three-dimensional range formed between the inner surface of the counter electrode and the tip of the discharge electrode. By generating an electric field, it is possible to generate a charged fine particle liquid by more efficiently concentrating charges on the liquid held in the discharge electrode.

  In addition to the effect of the invention according to any one of claims 1 to 3, the invention according to claim 4 efficiently discharges the charged fine particle liquid discharged from the discharge electrode toward the counter electrode outside the apparatus. There is an effect that it can be sent out.

  In addition to the effect of the invention according to any one of claims 1 to 4, the invention according to claim 5 prevents the electric field from concentrating on the counter electrode and prevents discharge on the counter electrode side. There is an effect that the liquid can be supplied more efficiently and stably.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings. In FIG. 1, the electrostatic atomizer of the 1st example in embodiment of this invention is shown roughly. The electrostatic atomizer includes a discharge electrode 1 having a rod shape, a counter electrode 2 having a discharge hole 2a at the center and a distance from the tip 1a of the discharge electrode 1, and the tip of the discharge electrode 1. A liquid supply means 3 for supplying a liquid (not shown) for electrostatic atomization such as water to the part 1a, and a discharge electrode 1 and a counter electrode 2 that are electrically connected to each other. And a high voltage applying unit 4 for applying a voltage. In the illustrated example, the tip 1a of the discharge electrode 1 is rounded, but it may be sharp.

  In this example, as the liquid supply means 3, the discharge electrode 1 is formed of a material having high thermal conductivity such as aluminum, and the base end portion 1b of the discharge electrode 1 is connected to the cooling unit 5a side of the Peltier unit 5. It is connected to. As a result, the discharge electrode 1 itself is cooled by the Peltier unit 5 to generate condensed water on the surface of the discharge electrode 1, and this condensed water is used as a liquid for electrostatic atomization. In the present invention, the liquid supply means 3 is not particularly limited. For example, the discharge electrode 1 is made of a porous material such as porous ceramic or a material having pores, and the base end 1b side of the discharge electrode 1 is connected to a liquid tank. It may be configured such that it is immersed in a liquid stored in (not shown).

  And in this example, the inner surface 2b of the said counter electrode 2 located facing the front-end | tip part 1a of the discharge electrode 1 is made into the concave surface formed so that the front-end | tip part 1a of the discharge electrode 1 may be enclosed (FIG. 2). reference). The cross-sectional shape obtained by cutting the inner surface 2b in a plane passing through the tip 1a of the discharge electrode 1 is drawn with the shortest distance d from the tip 1a to the counter electrode 2 as the radius centered on the tip 1a of the discharge electrode 1. It has an arcuate cross-sectional shape.

  As a result, the electric field generated between the inner surface 2b of the counter electrode 2 and the tip 1a of the discharge electrode 1 is such that the distance from the tip 1a of the discharge electrode 1 of the inner surface 2b of the counter electrode 2 is the shortest distance d. The arc line portion (dotted line portion in FIG. 2) and the distal end portion 1 a of the discharge electrode 1 are strongly generated. The counter electrode 2 is formed by cutting or bending a conductive material made of a metal such as SUS304. However, the counter electrode 2 may be formed by performing metal plating after resin molding, or may be formed of conductive plastic or the like. A conductive substance may be used.

  In the electrostatic atomizer having the above-described configuration, the liquid supply means 3 supplies and holds the liquid to the distal end portion 1a of the discharge electrode 1, and in this state, the high voltage application unit 4 causes the distal end portion 1a side of the discharge electrode 1 to be negative. When a high voltage is applied between the discharge electrode 1 and the counter electrode 2 so that electric charges are concentrated as an electrode, the liquid held at the tip 1a of the discharge electrode 1 is charged, and the charged liquid is subjected to Coulomb force. The liquid level of the liquid rises locally in a conical shape. Charge concentrates at the tip of this cone-shaped liquid (Taylor cone), the charge density becomes high, and the liquid breaks and scatters (so-called Rayleigh split) so that it can be repelled by the repulsive force of the high-density charge. Repeatedly causes electrostatic atomization. Due to this electrostatic atomization phenomenon, a large amount of nanometer-sized charged fine particle liquid containing active species (radicals) is generated and released from the discharge hole 2a to the outside of the apparatus by riding on the ion wind.

  Here, in this example, as described above, the arc line portion surrounding the tip portion 1a of the discharge electrode 1 in the inner surface 2b of the counter electrode 2 has the shortest distance d between the tip portion 1a of the discharge electrode 1. A strong electric field is generated within a wide range between the arc line portion of the counter electrode 2 and the distal end portion 1a of the discharge electrode 1. Therefore, the concentration of the electric field on the tip 1a of the discharge electrode 1 is increased, and it becomes possible to generate a charged fine particle liquid by efficiently concentrating charges on the liquid held in the discharge electrode 1.

  Next, the electrostatic atomizer of the second example in the embodiment of the present invention will be described, but the description of the same configuration as the above-described first example among the configurations of the present example will be omitted. As shown schematically in FIG. 3, the cross-sectional shape of the concave inner surface 2b of the counter electrode 2 of this example is a continuous series of a plurality of straight lines that are located at the shortest distance d from the tip 1a of the discharge electrode 1. As a whole, it is formed along a circular arc line (dotted line portion in the figure) drawn with the tip end 1a of the discharge electrode 1 as the center and the shortest distance d as the radius. Even if the cross-sectional shape is such a substantially arc-shaped polygonal line shape, the inner surface 2b of the counter electrode 2 is strong within a wide range between the tip portion 1a of the discharge electrode 1 as in the first example. An electric field will be generated. Therefore, the concentration of the electric field on the distal end portion 1a of the discharge electrode 1 is increased, and the charged fine particle liquid can be generated by efficiently concentrating charges on the liquid held in the discharge electrode 1.

  Next, although the electrostatic atomizer of the 3rd example in the embodiment of the present invention is explained, explanation is omitted about the same composition as the 1st example mentioned above among the composition of this example. As shown schematically in FIG. 4, the counter electrode 2 of this example has a plurality of emission holes 2 a formed in the counter electrode 2 by meshing the whole or a part thereof. As a result, the charged fine particle liquid that is diffused and discharged from the distal end portion 1a of the discharge electrode 1 toward the counter electrode 2 can be efficiently sent out of the apparatus. Needless to say, the same configuration can be adopted in the second example.

  Next, although the electrostatic atomizer of the 4th example in the embodiment of the present invention is explained, explanation is omitted about the same composition as the 1st example mentioned above among the composition of this example. As shown schematically in FIG. 5, the counter electrode 2 of this example has a partial cross-sectional shape near the tip 1a of the discharge electrode 1, with the tip 1a of the counter electrode 2 as the center and the shortest distance d as the radius. The arc shape is drawn, and the cross-sectional shape of the other part is a shape bent from the end of the arc shape to the opposite side via an inflection point. In this way, only a part of the inner surface 2b facing the discharge electrode 1 side of the counter electrode 2 is formed along a circular arc drawn with a shortest distance d from the tip 1a of the discharge electrode 1. However, the same effect can be obtained. In the present example, a plurality of discharge holes 2a are provided at an equal interval at least in the circumferential direction in a circular arc-shaped portion centering on the tip 1a of the discharge electrode 1.

  Next, although the electrostatic atomizer of the 5th example in the embodiment of the present invention is explained, explanation is omitted about the same composition as the 1st example mentioned above among the composition of this example. As shown schematically in FIG. 6, the counter electrode 2 of this example has a concave inner surface 2 b facing the discharge electrode 1 side of the counter electrode 2, the tip of the discharge electrode 1 as the center, and the tip of the discharge electrode 1. The surface is a hemispherical surface with the shortest distance d between the portion 1a and the counter electrode 2 as a radius.

  In this example, the entire hemispherical inner surface 2 b of the counter electrode 2 surrounding the distal end portion 1 a of the discharge electrode 1 is a portion that is separated from the distal end portion 1 a of the discharge electrode 1 by the shortest distance d. Since a strong electric field is generated within a wide three-dimensional range between the entire inner surface 2b and the tip 1a of the discharge electrode 1, the concentration of the electric field with respect to the tip 1a of the discharge electrode 1 is first. Compared to one example, the charge is further increased, and the charged fine particle liquid can be generated by more efficiently concentrating charges on the liquid held in the discharge electrode 1.

  Also in this example, the characteristic configuration of the second example is applicable. That is, for example, even if the cross-sectional shape of the inner surface 2b of the counter electrode 2 is a configuration in which a plurality of straight lines separated by the shortest distance d from the distal end portion 1a of the discharge electrode 1 are continuous (see FIG. 3). As a whole, if the structure is formed along a spherical surface (dotted line portion in FIG. 6) drawn with the tip portion 1a of the discharge electrode 1 as the center, the above effect of the present example can be obtained. In this case, the inner surface 2b of the counter electrode 2 is a hemispherical surface formed by combining a plurality of planes formed at a shortest distance d from the distal end portion 1a of the discharge electrode 1.

  The configuration of the third example and the configuration of the fourth example are also applicable in this example. That is, a plurality of discharge holes 2a may be formed in the counter electrode 2 by meshing the whole or a part of the counter electrode 2 (see FIG. 4), or the tip portion 1a of the discharge electrode 1 in the counter electrode 2 may be formed. You may form only a near part along the spherical surface drawn centering on the front-end | tip part 1a of the discharge electrode 1 (refer FIG. 5).

  Next, the sixth example of the electrostatic atomizer in the embodiment of the present invention will be described, but the description of the same configuration as the fifth example described above will be omitted. The counter electrode 2 of this example is provided with a convex curved surface 30 for preventing discharge at the end of the inner surface 2b facing the discharge electrode 1, as schematically shown in FIG.

  In general, when the discharge electrode 1 and the counter electrode 2 are installed close to each other (for example, when the shortest distance d is 3 mm or less), the discharge is caused at the end of the inner surface 2b of the counter electrode 2 facing the discharge electrode 1 side. Is likely to occur. This is because the end portion of the inner surface 2b becomes, for example, a convex corner portion between the inner surface of the discharge hole 2a and the electric field is easily concentrated on the tip of the corner portion. If discharge occurs on the counter electrode 2 side, positive ions are generated, and these positive ions act to neutralize the charged fine particle liquid having the opposite polarity, thereby inhibiting the stable supply of the charged fine particle liquid. .

  On the other hand, by forming the convex curved surface 30 with a radius of curvature of about 0.3 mm and preventing concentration of the electric field on the counter electrode 2, discharge on the counter electrode 2 side can be prevented. As a result, charged fine particles The liquid can be supplied efficiently and stably. Of course, even when the same configuration of the convex curved surface 30 is applied to the configurations of the first to fourth examples, the same effect can be obtained.

  The configuration of each example described above can be modified as appropriate without departing from the gist of the present invention, and the configuration of each example can be combined as appropriate.

It is explanatory drawing of the electrostatic atomizer of the 1st example in embodiment of this invention. It is explanatory drawing of a counter electrode same as the above. It is explanatory drawing of the counter electrode of the electrostatic atomizer of the 2nd example in embodiment of this invention. It is explanatory drawing of the counter electrode of the electrostatic atomizer of the 3rd example in embodiment of this invention. It is explanatory drawing of the counter electrode of the electrostatic atomizer of the 4th example in embodiment of this invention. It is explanatory drawing of the counter electrode of the electrostatic atomizer of the 5th example in embodiment of this invention. It is explanatory drawing of the counter electrode of the electrostatic atomizer of the 6th example in embodiment of this invention. It is explanatory drawing of the counter electrode of the conventional electrostatic atomizer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Discharge electrode 1a Tip part 2 Counter electrode 2a Ejection hole 2b Inner surface 3 Liquid supply means 4 High voltage application part 30 Convex curve

Claims (5)

  A discharge electrode; a counter electrode located at a distance from the discharge electrode; a liquid supply means for supplying a liquid to the discharge electrode; and a high voltage applying means for applying a high voltage between the discharge electrode and the counter electrode. In the electrostatic atomizer that discharges the charged fine particle liquid generated by applying a high voltage to the liquid held by the discharge electrode, the cross-sectional shape of at least a part of the inner surface of the counter electrode facing the discharge electrode is An electrostatic atomizer characterized in that the electrostatic atomizer is formed along an arc line centered on the tip of the electrode and having a shortest distance from the tip of the discharge electrode to the counter electrode as a radius.   At least a part of the inner surface facing the discharge electrode side of the counter electrode is formed along a spherical surface with the tip portion of the discharge electrode as the center and the shortest distance from the tip portion of the discharge electrode to the counter electrode as a radius. The electrostatic atomizer according to claim 1, wherein the electrostatic atomizer is provided.   At least a part of the inner surface of the counter electrode facing the discharge electrode is a hemispherical surface centered on the tip of the discharge electrode and having a radius of the shortest distance from the tip of the discharge electrode to the counter electrode. The electrostatic atomizer according to claim 2.   The electrostatic atomizer according to any one of claims 1 to 3, wherein the counter electrode has a plurality of discharge holes. 5. The electrostatic atomization according to claim 1, wherein the counter electrode is provided with a convex curved surface for preventing discharge at an end portion of an inner surface facing the discharge electrode side. apparatus.

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