KR20090103406A - Nonconductor Electrostatic Spray Apparatus and Method Thereof - Google Patents

Abstract

PURPOSE: A nonconductor electrostatic spraying apparatus and a method for the same are provided to improve spraying efficiency and to minimize the total volume thereof. CONSTITUTION: A nonconductor electrostatic spraying apparatus comprises a groove nozzle(100), fluid supplier, and power supply unit. The groove nozzle comprises a capillary tube(10) and non-conductive nozzle portion(20). An electric conductive fluid(600) passes through the capillary tube. The nozzle portion sprays the electric conductive fluid passed through the capillary tube. The fluid supplier supplies the electric conductive fluid to the one end of the capillary tube. The power supply unit supplies the predetermined degree of power to the capillary tube.

Description

Nonconductor Electrostatic Spray Apparatus and Method Thereof}

The present invention relates to an electrostatic spraying device, and more particularly, to generate a large number of cones stably under high flow conditions, satisfying high flow rate spraying, and miniaturization is possible for high flow rate electrostatic spraying suitable for a highly integrated multi-groove nozzle device. A non-conducting electrostatic spraying device and electrostatic spraying method.

In general, the electrostatic spray device refers to a spray device that splits a liquid into small droplets by purely electric force alone. Such electrostatic spraying has the property of generating charged microdroplets having a monodisperse distribution in the cone-jet mode. However, the conjet mode appears only at low flow rate, so the field where the electrostatic spraying is applied is limited. In order to solve the problem of low flow rate, even if a multi-nozzle is manufactured using a plurality of general nozzles, there is a problem that it is difficult to obtain a large effect because the flow rate from one nozzle is small.

In order to solve this low flow problem, the conductor groove nozzle developed by Duby et al. In 2006 utilizes a strong electric field generated at the edge of several grooves processed at the nozzle tip. This can be reliably controlled by allocating a plurality of conejets generated in a multi-jet mode to each groove, thereby generating a stable conejet mode in one nozzle.

However, in the case of the conductor groove nozzle, it is difficult to make multiple nozzles due to the strong repulsive force generated at the edge of the groove and the outer edge of the groove nozzle tip. In addition, current manufacturing technology is difficult to process the conductor groove nozzle as a small nozzle produced by the MEMS process has a high integration limit. Therefore, electrostatic spraying is possible with a single nozzle, but there is a problem that does not significantly improve the flow problem of electrostatic spraying because of the limitation of high integration.

Accordingly, the present invention has been made to solve the above problems, and the present invention satisfies high flow rate spraying, which is an advantage of conventional conductor groove nozzles, and provides a non-conductive electrostatic spraying device and a spraying method capable of ultra-high integration. There is this.

In order to achieve the above object, as a specific means of the present invention, the non-conducting electrostatic spraying device, the nozzle nozzle of the non-conductive material is sprayed capillary tube through which the electroconductive solution and the electroconductive solution passed through the capillary tube; A fluid supply device for supplying an electrically conductive solution to the capillary; And a voltage applying unit for applying a voltage to the capillary tube, wherein the plurality of grooves are formed such that the nozzle portion is sprayed with the electroconductive solution passing through the capillary tube.

In addition, the groove of the nozzle portion is characterized in that the radially arranged high flow rate spraying is possible.

An object of the present invention as described above is another category, supplying an electroconductive solution from the fluid supply device to the capillary of the groove nozzle; Applying a polarity voltage from the voltage application portion to the capillary of the groove nozzle to cause the supplied solution to have polar ions; Electroconductive solution having a polar ion is moved to the nozzle portion of the groove nozzle to generate a conjet in each groove using a plurality of grooves formed at the bottom of the nozzle portion as each flow path and spraying the electroconductive solution; It is characterized by a spraying method.

By implementing the nozzle portion of the non-conducting electrostatic spray device of the present invention as a non-conductor, there is no electric field generated in the nozzle portion itself, it is easy to manufacture a multi-groove nozzle.

In addition, since it is possible to miniaturize using the MEMS process, it is advantageous for high integration, so that the flow rate restriction of the spray device can be alleviated to improve the spraying efficiency.

In addition, since the voltage section forming the home mode is wide, the stability of electrostatic spraying is improved, and there is an effect that can be safely used without generating a corona discharge.

The following drawings, which are attached in this specification, illustrate the preferred embodiments of the present invention, and together with the detailed description thereof, serve to further understand the technical spirit of the present invention, and therefore, the present invention is limited only to the matters described in the drawings. It should not be interpreted.

1 is a schematic view showing the configuration of a non-conducting electrostatic spraying device according to the present invention,

2 is a perspective view of a groove nozzle according to the present invention;

3 is a bottom view of the nozzle unit according to the present invention;

4 is a side view of the nozzle unit according to the present invention;

5 is a graph showing the size of the droplets generated in each groove formed in the nozzle unit according to the flow rate,

Figure 6 is a schematic experimental apparatus for identifying the characteristics of the non-conducting electrostatic spraying device according to the present invention,

7 is a flowchart showing step by step the electrostatic spraying method according to the present invention;

8 is a graph showing the electrostatic spraying mode as the voltage applied to the working fluid is increased by the voltage generating unit according to the present invention;

Figure 9 is a photograph showing the home mode spray shape of the non-conducting electrostatic spraying device according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10 capillary 20 nozzle part

30: protrusion 40: groove

100: groove nozzle 200: voltage applied

300: fluid supply device 400: electrode plate

500: microcurrent meter 600: electroconductive solution (working fluid)

601 Liquid Cone 602 Liquid Liquor

603: Droplets

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Configuration of electrostatic spraying device>

1 is a schematic view showing the configuration of an electrostatic spraying device according to the present invention. As shown in FIG. 1, the electrostatic spraying device according to the present invention includes a groove nozzle 100, a fluid supply device 300 and a groove nozzle 100 connected to one end of a capillary tube 10 of the groove nozzle 100. It consists of a voltage applying unit 200 is connected through one end of the capillary tube 10 and the wire.

Figure 2 shows a perspective view of a groove nozzle according to the invention, Figure 3 shows a bottom view of the nozzle unit according to the invention, Figure 4 shows a side view of the nozzle unit according to the invention.

As shown in FIG. 2, the groove nozzle 100 according to the present invention includes a capillary tube 10 and a nozzle unit 20.

Here, the capillary tube 10 is a 1.6 mm outer diameter and a hollow tube for passing a predetermined electroconductive solution 600 (hereinafter referred to as 'working fluid') supplied from the fluid supply device 300. The capillary tube 10 may be made of any conductive material capable of applying a voltage to ensure that the working fluid 600 supplied according to the polarity voltage applied from the voltage applying unit 200 has the corresponding ions. Do. However, preferably, it is preferably made of aluminum or stainless steel.

The nozzle unit 20 according to the present invention is provided under the capillary tube 10 and has a tubular shape having an inner diameter of 1.6 mm equal to the outer diameter of the capillary tube 10 so that the capillary tube 10 can be coupled thereto. A plurality of protrusions 30 and grooves 40 through which the working fluid is discharged are radially formed at the lower end of the nozzle unit 20. The plurality of protrusions 30 and the grooves 40 may be formed in the same size to equalize the flow rate of the working fluid 600 flowing through the grooves 40 as the flow paths. And the nozzle unit 20 is preferably made of a non-conductive material, preferably made of a thermosetting resin.

The working fluid 600 passing through the capillary tube 10 and the nozzle unit 20 acts as a flow path through the groove 40 formed between the plurality of protrusions 30 formed at the bottom of the nozzle unit 20 as a flow path. Formed and maintained. The electrostatic spraying device having the nozzle unit 20 made of a non-conductive material does not have an electric field generated by the nozzle unit 20 itself. Therefore, corona discharge does not occur and is safe, and only a space charge effect by droplets occurs. In addition, it can be miniaturized through a MEMS process and the like, thereby enabling high integration.

When the number of the protrusions 30 and the grooves 40 formed in the nozzle unit 20 is 12, and the flow rate of the working fluid 600 flowing through the groove nozzle 100 is 12 ml / h, as shown in the graph of FIG. 5. Likewise, the droplet sizes generated in each of the twelve grooves 40 are approximately the same. In addition, the droplet size and the amount of charge generated in one groove 40 are the same as the cone jet mode spraying of a general nozzle having a flow rate of 1 ml / h. That is, the flow rates of the 12 normal nozzles can be replaced by one groove nozzle. Here, the horizontal axis of Figure 5 represents each groove, the vertical axis represents the size of the droplets.

The fluid supply device 300 according to the present invention is configured to supply the working fluid 600 to the capillary tube 10 provided in the groove nozzle 100. Any fluid supply device 300 may be used as long as it can perform this function. However, it is preferable to use a syringe pump.

The voltage applying unit 200 according to the present invention was configured to apply a polarity voltage to the capillary tube 10. Any device can be used as long as it can perform this function. However, it is preferable to use a voltage generator. When a voltage having a '+' electrode is applied from the voltage applying unit 200 to the capillary 10, negative ions dissolved in the working fluid 600 are implanted or moved to the inner wall surface of the capillary 10. The working fluid 600 is ejected out of the capillary 10 by the repulsive force of the positive ions applied to the capillary 10 and the positive ions remaining in the working fluid, and moves to the nozzle unit 20. .

<Operation of electrostatic spraying device>

The non-conducting electrostatic spraying device uses a groove 40 formed between the plurality of protrusions 30 formed in the nozzle portion 20 of the groove nozzle 100 as the respective flow paths so that the conjet is generated and maintained in the protrusions. .

Figure 6 shows a schematic experimental apparatus for identifying the characteristics of the electrostatic spraying device according to the present invention. The syringe pump, which is the fluid supply device 300, supplies the working fluid 600 to the capillary 10 provided in the home nozzle 100 (S100). In order to apply polar ions to the working fluid 600, a high voltage polarity voltage is applied to the capillary 10 from the voltage generator, which is the voltage applying unit 200 (S200). In this experimental apparatus, the distance between the nozzle part 20 of the groove nozzle 100 and the electrode plate 400 was set to 30 mm. Here, the electrode plate 400 uses a metal plate of a conductive material. The microcurrent meter 500 is connected to the electrode plate 400 to measure the current flowing through the electrode plate 400. In this experiment, the working fluid 600 uses ethanol, and the flow rate of the working fluid is 6 ml / h.

If a positive high voltage of tens of kV is applied from the voltage applying unit 200 to the capillary tube 10 of the groove nozzle 100, the capillary tube 10 acts as an anode, so that negative ions in the working fluid 600 are applied. Receives the attraction force and moves to the inner wall surface of the capillary tube 10. At this time, the positive ions are moved to the lower portion of the nozzle unit 20 by the repulsive force. The working fluid 600 moved to the lower part of the nozzle unit 20 uses a plurality of grooves 40 formed at the lower end of the nozzle unit 20 as a flow path to form a cone jet and sprays the working fluid (S300). When the voltage applied to the working fluid 600 is small, the repulsive force of the electric force and the positive ion is less than the surface tension of the working liquid so that the droplet 603 is not sprayed, but when the voltage increases, the electric force and the positive ion are increased. The repulsive force of the is greater than the surface tension of the working fluid 600, the droplet 603 of the working fluid 600 is sprayed from the nozzle unit 20 provided in the groove nozzle (100). That is, when the voltage is further increased, the liquid cone 601 is formed in the groove 40 between the plurality of protrusions 30 formed in the nozzle unit 20. The working fluid 600 formed of the liquid cone 601 receives a surface shear stress to form a liquid column 602. At the end of the formed liquid column 602, the liquid is broken and sprayed into the droplets 603 due to the disturbance of the surface waves acting on the surface of the liquid column 602. This is called a cone-jet mode.

In the electrostatic spraying device according to the present invention, a plurality of conjets are formed in the plurality of grooves 40, which is called a multi-jet mode.

7 is a graph showing a change in spray current as the voltage applied from the voltage applying unit increases, and FIG. 9 is a photograph showing a home mode spray shape of the non-conducting electrostatic spraying device according to the present invention. Here, the horizontal axis of FIG. 7 is a voltage applied from the voltage applying unit 200 to the capillary tube 10, and the vertical axis is a spray current measured by the microcurrent meter 500. Since the non-conducting electrostatic spraying device is sprayed by the electric field formed by the working fluid 600 to which a high voltage is applied, the change in the electric field according to the applied voltage is relatively smaller than that of the conductive spray device. Therefore, the voltage section in which the conjet mode occurs and the voltage section in the home mode are relatively wider than those in the conductor home nozzle. When the voltage is continuously increased in the multi-jet mode, the number of jets equal to the number of grooves 40 processed in the nozzle unit 20 in a certain voltage condition or more shows the same shape as the con-jet mode, and this mode is maintained for a predetermined voltage. This is called home mode. Like the conjet mode, the home mode can be seen in FIG. 7 and FIG. 9 that the spray current is kept constant even when the voltage is increased.

<Variation example>

In another embodiment of the present invention, the nozzle unit 20 may be arranged not only in a radial manner, but also in a hemispherical, vertical, or the like to enable high flow electrostatic spraying.

In another embodiment, the non-conducting electrostatic spraying device of the present invention is applicable to catalytic combustion device for removing VOC and odor, and is applicable to particle charging device for improving electrostatic precipitator efficiency, and also to thin film coating device such as semiconductor and LCD. Of course it is applicable.

As described above, those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. .

Claims (11)

A groove nozzle (100) consisting of a capillary tube (10) through which an electroconductive solution passes and a nozzle unit (20) of nonconductive material through which the electroconductive solution passed through the capillary tube (10) is sprayed; A fluid supply device 300 for supplying the electroconductive solution 600 to one end of the capillary tube 10; And And a voltage applying unit (200) for applying a predetermined voltage to the capillary tube (10). The method of claim 1, The capillary 10 is a non-conductive electrostatic spray device, characterized in that the conductive material. The method of claim 2, The capillary tube 10 is a non-conducting electrostatic spray device, characterized in that the aluminum or stainless steel material. The method of claim 1, The nozzle unit 20 is a non-conducting electrostatic spraying device, characterized in that a plurality of protrusions 30 and the groove 40 is formed so that the electroconductive solution passed through the capillary tube (10). The method of claim 4, wherein Non-conducting electrostatic spraying device, characterized in that the grooves formed between the plurality of protrusions (30) and the plurality of protrusions (30) are arranged radially. The method of claim 4, wherein Non-conducting electrostatic spray device, characterized in that the size of the plurality of protrusions 30 and the size of the groove (40) formed between the plurality of protrusions (30). The method of claim 1, The nozzle unit 20 is a non-conducting electrostatic spraying device, characterized in that the thermosetting resin. The method of claim 1, The fluid supply device 300 is a non-conducting electrostatic spray device, characterized in that the syringe pump. The method of claim 1, The voltage applying unit 200 is a non-conducting electrostatic spraying device, characterized in that the voltage generator. The method of claim 1, The electroconductive solution (600) supplied from the fluid supply device (300) to the capillary (10) has a corresponding polar ions according to the polarity voltage applied to the capillary (10). Supplying an electroconductive solution 600 from the fluid supply device 300 to the capillary 10 of the groove nozzle 100 (S100); Applying a polarity voltage from the voltage applying unit (200) to the capillary (10) of the groove nozzle (100) so that the supplied electroconductive solution (600) has polar ions (S200); And The electrically conductive solution 600 having polar ions moves to the nozzle unit 20 of the groove nozzle 100 to use each of the grooves 40 formed at the lower end of the nozzle unit 20 as the respective flow paths. A cone jet is generated at 40 and the electroconductive solution 600 is sprayed (S300); electrostatic spraying method of a non-conducting electrostatic spraying device comprising a.