JP3873204B2 - Liquid jet generation method by EHD pumping and liquid jet generation apparatus by EHD pumping - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for ejecting a liquid (electrically insulating liquid) using a so-called EHD (Electrohydrodynamic) pumping phenomenon and an apparatus for generating a liquid jet by the ejection method.
[0002]
[Prior art]
It has long been known that when a high voltage is applied to an electrically insulating gas or liquid, a fluid flow phenomenon called an EHD pumping phenomenon occurs due to the interaction between the electric field and the flow field in the fluid. And if the EHD pumping phenomenon is applied, the liquid can flow without requiring a mechanical moving mechanism. Therefore, in the future, especially the EHD pumping phenomenon of the liquid will be, for example, a heat pipe, a pump, a fountain device, a liquid circulation device, a heat exchange It is expected to be industrially widely applicable in various practical fields such as a system or a power device using a liquid jet flow.
[0003]
Although there are still many unclear points regarding the EHD pumping phenomenon that occurs in liquids, several generation mechanisms have already been reported. The most common mechanism is a flow mechanism called ion drag pumping. From the tip of a sharp electrode to which a high voltage is applied, ions injected into the liquid based on field emission, field ionization, corona discharge, etc. This is a flow phenomenon that occurs due to energy conversion with neutral molecules under the Coulomb force by an electric field. Then, it has been reported that a liquid jet reaching a flow velocity of about 1 m / s is generated from a sharp electrode (needle electrode or blade electrode) toward a flat plate electrode facing this.
[0004]
As another generation mechanism of the EHD pumping phenomenon, a flow mechanism called induction pumping is known. This is a flow phenomenon caused by the interaction between the induced charge and the electric field. This induced charge generated by the electric field is caused by the non-uniformity of the liquid conductivity, and the non-uniformity of the liquid conductivity is caused by the unequal temperature of the liquid. Caused by distribution or liquid heterogeneity (eg, separated two-layer fluid).
[0005]
[Problems to be solved by the invention]
However, when the liquid EHD pumping phenomenon is utilized and put into practical use in various industrial fields, there is a great difficulty in using the EHD pumping phenomenon based on the flow mechanism of the above-mentioned ion drag pumping or induction pumping. That is, in the liquid jet generation method by EHD pumping along the ion drag pumping mechanism, since charged particles are injected into the liquid, there is a problem that the electrical characteristics of the liquid gradually deteriorate and cannot withstand long-term use. The liquid jet generation method by EHD pumping along the inductive pumping mechanism has a fundamental difficulty that it cannot be used for thermally insulated constant temperature liquid.
[0006]
In view of the above situation, the present invention is not based on the flow mechanism of the conventional ion drag pumping and induction pumping, and is also completely different from the flow mechanism of electrostrictive force based on the polarization effect of the liquid. In other words, the dissociation / recombination reaction of the electrolyte component present in the liquid is unbalanced by the action of the high electric field, and the generated dissociated ions form a heterocharge layer near the electrode surface, so that the electrode and the heterocharge layer By focusing on the flow mechanism in which the attractive force acting in between brings about the flow, it does not use a sharply shaped electrode and therefore does not involve charge injection into the insulating liquid, and against a thermally insulated constant temperature liquid Even a liquid jet generation method capable of generating a highly directional liquid jet by EHD pumping, and the method It is intended to obtain a liquid jet generating apparatus capable of generating a highly directional liquid jets according to HD pumping. An object is to generate a liquid jet having a large pumping pressure and high directivity without deteriorating the insulating liquid over a long period of time.
[0007]
[Means for Solving the Problems]
In order to generate a liquid jet by EHD pumping that meets the above-mentioned purpose, the present invention provides a pseudo donut shape in which both end faces are formed into a smooth arc shape with an annular or cylindrical shape penetrating a liquid circulation hole in the direction of the central axis. One end of the electrode is opposed to the flat plate electrode with a gap therebetween to form an electrode system, and at least a part of the electrode system including the portion where the pseudo donut-like electrode and the flat plate electrode face each other is placed in the electrically insulating liquid, By applying a DC high voltage between the pseudo donut-like electrode and the flat plate electrode, the above-mentioned electrically insulating liquid is ejected from one end face of the pseudo donut-like electrode through the liquid flow hole of the pseudo donut-like electrode. To.
[0008]
In addition, in order to improve the directivity of the liquid jet by EHD pumping that meets the above-mentioned purpose, the present invention is formed in an annular shape or a cylindrical shape with a liquid flow hole penetrating in the direction of the central axis, and both end surfaces thereof are formed into smooth arc shapes. One end of the pseudo donut-like electrode is opposed to the flat plate electrode with a gap, and a nozzle that penetrates the conical conical liquid circulation hole connected coaxially with the liquid circulation hole of the pseudo donut-like electrode is connected to the pseudo donut-like electrode. An electrode system is formed by coupling to the other end, and at least a part of the electrode system including a portion where the pseudo donut-like electrode and the flat plate electrode face each other is placed in an electrically insulating liquid, and the pseudo donut-like electrode and the flat plate electrode By applying a direct current high voltage in between, the electrically insulating liquid is ejected from the tip of the nozzle through the liquid circulation hole of the pseudo donut-shaped electrode. That.
[0009]
In order to further enhance the directivity of the liquid jet by EHD pumping, the present invention provides a pseudo-doughnut-shaped electrode in which the liquid flow hole is penetrated in the direction of the central axis and is formed into a smooth arc shape at both ends thereof A liquid having a conical conical liquid flow hole that is concentrically connected to the liquid flow hole of the pseudo-doughnut-like electrode and a flow component perpendicular to the central axis direction. A spiral nozzle having an auxiliary liquid passage for introducing a flow into the large diameter portion at the base of the conical conical liquid circulation hole is coupled to the other end of the pseudo donut-like electrode, and an auxiliary ring electrode is provided around the inlet of the auxiliary liquid passage. The auxiliary plate electrode is opposed to the auxiliary ring electrode through a gap to form an electrode system, and the portion where the pseudo donut-like electrode and the flat plate electrode are opposed to each other, and Place at least a part of the electrode system including the part where the auxiliary ring electrode and the auxiliary plate electrode face each other in the electrically insulating liquid, and between the pseudo donut-like electrode and the plate electrode and between the auxiliary ring electrode and the auxiliary plate electrode. At the same time, by applying a high DC voltage, the electrically insulating liquid is ejected from the tip of the spiral nozzle through the liquid flow hole of the pseudo donut-shaped electrode.
[0010]
In order to increase the flow velocity and pumping pressure of the liquid jet by EHD pumping, the present invention uses diethylene glycol monobutyl ether acetate or dodecanedioic acid-nbutyl as the electrically insulating liquid.
[0011]
In the present invention, as a device for generating a liquid jet by EHD pumping that meets the above-mentioned purpose, a pseudo donut shape in which the liquid circulation hole penetrates in the direction of the central axis or a cylindrical shape, and both end surfaces thereof are formed into a smooth arc shape. A basic + electrode system is formed by an electrode and a flat plate electrode opposed to one end of the pseudo-doughnut-like electrode with a gap therebetween, and at least the facing part of the pseudo-doughnut electrode and the planar electrode is held in the electrically insulating liquid. It is assumed that a DC high voltage is applied between the pseudo donut-like electrode and the flat plate electrode.
[0012]
In addition, the liquid jet generator by EHD pumping of the present invention is formed in an annular or cylindrical shape in which the liquid flow hole penetrates in the direction of the central axis, and both end surfaces thereof are formed into a smooth arc shape in order to improve the directivity of the liquid jet. The pseudo-doughnut-shaped electrode, the flat plate electrode facing one end of the pseudo-doughnut-shaped electrode with a gap, and the conical liquid flow hole that is concentrically connected to the liquid flow hole of the pseudo-doughnut-shaped electrode are formed to simulate An electrode system is formed with a nozzle coupled to the other end of the doughnut-shaped electrode, and at least the opposing portion of the pseudo-doughnut-shaped electrode and the plate electrode is held in the electrically insulating liquid. The high DC voltage is applied between the two.
[0013]
Furthermore, in order to further enhance the directivity of the liquid jet, the liquid jet generator by EHP pumping according to the present invention is formed into an annular shape or a cylindrical shape in which the liquid flow hole penetrates in the direction of the central axis, and both end surfaces thereof are formed into a smooth arc shape. The pseudo-doughnut-shaped electrode, the flat plate electrode opposed to one end of the pseudo-doughnut-shaped electrode with a gap therebetween, and the conical liquid flow hole that is connected to the liquid flow hole of the pseudo-doughnut-shaped electrode are formed. And an auxiliary liquid passage for introducing a liquid flow having a flow component perpendicular to the direction of the central axis into the root large-diameter portion of the conical liquid circulation hole is formed and coupled to the other end of the pseudo-doughnut-shaped electrode An electrode system having a nozzle, an auxiliary ring electrode disposed around the inlet of the auxiliary liquid passage, and an auxiliary plate electrode opposed to the auxiliary ring electrode with a gap And at least the opposing portion of the pseudo donut-like electrode and the flat plate electrode and the opposing portion of the auxiliary ring electrode and the auxiliary flat plate electrode are held in the electrically insulating liquid. A high DC voltage is simultaneously applied between the auxiliary ring electrode and the auxiliary flat plate electrode.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
One of the basic embodiments of the present invention is that one end of a pseudo-doughnut-like electrode having a circular or cylindrical shape with a liquid circulation hole penetrating in the direction of the central axis and having both end surfaces formed into a smooth arc shape is a flat plate electrode. The electrode system is made to be opposed to each other with a gap, and at least a part of the electrode system including a portion where the pseudo donut-like electrode and the flat plate electrode face each other is placed in an electrically insulating liquid, A method of generating a liquid jet by EHD pumping in which the electrically insulating liquid is ejected from one end face of a pseudo donut-like electrode through a liquid flow hole of the pseudo donut-like electrode by applying a DC high voltage between the flat plate electrodes It is. This principle is based on pure conduction pumping caused by the generation of pressure due to the dissociated ions in the liquid forming a non-equilibrium layer (heterocharge layer) having a polarity different from that of the electrode in the vicinity of the electrode surface.
[0015]
In addition, another basic embodiment of the present invention includes a pseudo donut-like electrode having a circular or cylindrical shape with a liquid flow hole penetrating in the direction of the central axis, and a smooth arc shape at both ends thereof, and the pseudo donut A flat plate electrode opposed to one end of the electrode with a gap, and at least the facing portion of the pseudo donut electrode and the flat electrode is held in an electrically insulating liquid, and a direct current is provided between the pseudo donut electrode and the flat plate electrode. This is an apparatus for generating a liquid jet by EHD pumping equipped with an electrode system to which a high voltage is applied.
[0016]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the basic configuration of a liquid jet generator using EHD pumping according to an embodiment of the present invention. In FIG. 1, 1 is a pseudo donut-shaped electrode (high voltage electrode), and 2 is a flat plate electrode (ground electrode). The pseudo donut-like electrode 1 has an annular shape or a cylindrical shape that penetrates the liquid circulation hole 1a in the central axis Z direction, and its both end surfaces are shaped into a smooth arc R, such as field emission, field ionization, and corona discharge. The entire surface is smoothly molded so that there is no sharp protrusion that causes That is, the pseudo donut-like electrode 1 has a shape in which a donut shape having a circular cross section is slightly extended in the central axis Z direction. Then, one end of the pseudo-doughnut-shaped electrode 1 is opposed to the flat plate electrode 2 with a gap d to form an electrode system 10, and the electrode system 10 is submerged in the electrically insulating liquid 3. By applying a DC high voltage between the pseudo-doughnut-like electrode 1 and the plate electrode 2, that is, by applying a positive or negative DC high voltage to the pseudo-doughnut-like electrode 1 with respect to the potential of the plate electrode 2, EHD pumping Due to the phenomenon, a liquid jet of the electrically insulating liquid 3 is generated from one end face of the pseudo donut-like electrode 1 through the liquid circulation hole 1a of the pseudo-donut-like electrode 1, and the liquid jet moves the liquid surface of the electrically insulating liquid 3. Break and squirt high (long). The arrow A indicates the jet direction of the electrically insulating liquid 3, but this direction can be reversed depending on the type of the electrically insulating liquid 3 and the polarity of the DC high voltage applied to the pseudo-doughnut-like electrode 1.
[0017]
The dimensions of the electrode system 10 shown in FIG. 1 used in the experiment are as follows: the length B of the pseudo-doughnut-like electrode 1 is 10 mm, the radius of the arc R is 2.5 mm, the diameter C of the liquid circulation hole 1a is 3 mm, and the gap d. Is 2 mm.
[0018]
In the embodiment shown in FIG. 1, the entire electrode system 10 is submerged in the electrically insulating liquid 3, but a portion of the pseudo donut-like electrode 1 is submerged in the electrically insulating liquid 3 to form a pseudo donut-like shape. The ejection side of the electrode 1 can be lifted from the liquid surface of the electrically insulating liquid 3 and operated. In that case, a part of the electrode system including at least a portion where the pseudo donut-like electrode 1 and the flat plate electrode 2 face each other is placed in the electrically insulating liquid 3.
[0019]
FIG. 2 shows the configuration of a liquid jet generating apparatus using EHD pumping according to another embodiment of the present invention, which improves the directivity of the liquid jet. In FIG. 2, the pseudo-doughnut-shaped electrode 1, the fluid flow hole 1a, the flat plate electrode 2, the electrically insulating fluid (not shown), the direct current high voltage power source (not shown), the gap d and their mutual relationship are shown in FIG. It is the same as shown in. A polyethylene nozzle 25 cuts out the inside of the cylindrical material into a conical shape and penetrates a conical constricted liquid circulation hole 25a that is tapered in the liquid flow direction. The conical constricted liquid circulation hole 25a is connected to the liquid circulation hole 1a of the pseudo-doughnut-like electrode 1 in a coaxial manner by sharing the central axis Z, and is coupled to the other end of the pseudo-doughnut-like electrode 1 (an end face not facing the flat plate electrode 2). Has been. The pseudo donut-like electrode 1, the flat plate electrode 2, and the nozzle 25 constitute an electrode system 10. The electrode system 10 including at least a portion where the pseudo donut-like electrode 1 and the flat plate electrode 2 face each other is made of an electrically insulating fluid. An electrically insulating liquid is ejected from the tip of the nozzle 25 through the liquid flow hole 1a of the pseudo donut-like electrode 1 by applying a DC high voltage between the pseudo donut-like electrode 1 and the plate electrode 2 is there. According to the method and apparatus for generating a liquid jet shown in FIG. 2, by adding the nozzle 25 having the conical liquid flow hole 25a to the pseudo-doughnut-shaped electrode 1, the directivity of the liquid jet is increased and the reach of the liquid jet is increased. Can be stretched. The dimensions of the nozzle 25 shown in FIG. 2 used in the experiment are lengths E and F of 23 mm and 16 mm, respectively, and the discharge port diameter G of the conical conical liquid circulation hole 25a is 2 mm.
[0020]
FIG. 3 shows a configuration of a liquid jet generating apparatus by EHD pumping showing still another embodiment of the present invention. In order to further improve the directivity and convergence of the liquid jet, the nozzle shown in FIG. It is an improved spiral nozzle. In FIG. 3, the pseudo-doughnut-shaped electrode 1, the fluid circulation hole 1a, the flat plate electrode 2, the electrically insulating fluid (not shown), the gap d, and their mutual relationship are the same as those shown in FIGS. is there. 35 is a spiral nozzle made of polyethylene, and similarly to the nozzle 25 of FIG. 2, the spiral nozzle 35 has a narrowed conical liquid circulation hole 35a tapered in the liquid flow direction, and the narrowed conical liquid circulation hole 35a. Are connected coaxially with the liquid circulation hole 1a of the pseudo-doughnut-like electrode 1 and coupled to the other end (end surface not opposed to the plate electrode 2) of the pseudo-doughnut-like electrode 1.
[0021]
In addition to the constricted conical liquid circulation hole 35a, the spiral nozzle 35 introduces a liquid flow having a flow component perpendicular to the central axis Z direction into the large-diameter portion 35b at the root of the conical conical liquid circulation hole 35a. The auxiliary liquid passage 36 is formed, and an auxiliary ring electrode 37 having a small diameter is disposed around the inlet of the auxiliary liquid passage 36, and an auxiliary plate electrode (ground electrode) 38 is provided to the auxiliary ring electrode 37 through a gap s. Are opposed to each other. The pseudo donut-like electrode 1, the plate electrode 2, the spiral nozzle 35, the auxiliary ring electrode 37, and the auxiliary plate electrode 38 constitute an electrode system 10, and at least the opposing portion of the pseudo donut-like electrode 1 and the plate electrode 2 and the auxiliary electrode. The electrode system 10 including the opposing portion of the ring electrode 37 and the auxiliary plate electrode 38 is held in an electrically insulating fluid, and the pseudo donut-like electrode 1 and the plate electrode 2 are supplied from a DC high voltage power source (not shown). The electric insulating liquid is ejected from the tip of the spiral nozzle 35 through the liquid flow hole 1a of the pseudo donut-like electrode 1 by applying a DC high voltage between the auxiliary ring electrode 37 and the auxiliary flat plate electrode 38. It is.
[0022]
In addition, a short cylindrical guide body 39 is disposed inside the inner peripheral wall of the large-diameter portion at the base of the conical liquid flow hole 35a for constriction of the spiral nozzle 35 so that the cylindrical guide body 39 and the conical liquid flow through the constriction cone. A guide groove (annular slit) 40 is formed between the inner peripheral walls of the base large-diameter portion 35b of the hole 35a, and a small hole 41 is provided from the outer peripheral surface of the spiral nozzle 35 to the liquid guide groove 40. An auxiliary liquid passage 36 is formed by 40 and the small hole 41.
[0023]
When a high DC voltage is applied between the pseudo donut-like electrode 1 and the flat plate electrode 2 and between the auxiliary ring electrode 37 and the auxiliary flat plate electrode 38, an EHD flow occurs in the gap between the pseudo donut-like electrode 1 and the flat plate electrode 2, As a result, a liquid jet of an electrically insulating liquid is generated, and the liquid jet is ejected from the tip of the spiral nozzle 35. At the same time, an EHD flow also occurs in the gap between the auxiliary ring electrode 37 and the auxiliary plate electrode 38. Then, the liquid flow resulting therefrom is ejected through the small hole 41 and the guide groove 40 to the conical liquid flow hole 35a of the spiral nozzle 35. Since the liquid flow ejected from the guide groove 40 has a flow component in the radial direction toward the central axis Z of the conical conical liquid circulation hole 35a, it radiates to the main flow of the liquid jet in the conical conical liquid circulation hole 35a. Will give a velocity vector in the direction. As a result, the liquid jet converges on the central axis Z and the directivity increases, and the reach of the liquid jet can be extended. The dimensions of the spiral nozzle 35 shown in FIG. 3 used in the experiment are as follows: the diameter M of the small hole 41 is 1 mm, the diameter N of the auxiliary ring electrode 37 is 5 mm, the length H of the auxiliary plate electrode 38 is 20 mm, and the auxiliary ring. The gap s between the electrode 37 and the auxiliary plate electrode 38 is 2 mm.
[0024]
Various electric insulating liquids used for generating a liquid jet by EHD pumping are conceivable. In the process of the present invention, diethylene glycol monobutyl ether acetate (hereinafter abbreviated as “BCRA”), dodecanedioic acid-n-butyl (hereinafter referred to as “DBDN”). ”), Transformer oil (JIS-C2320) (hereinafter abbreviated as“ Tr-Oil ”), and fluorine-modified silicone oil (hereinafter abbreviated as“ FS-Oil ”).・ Thinking, and identifying their characteristics and practical superiority or inferiority. The liquid jet generated when the electrode system shown in FIG. 1 is installed in the above four types of electrically insulating liquids and a positive or negative DC high voltage is applied depends on the type of liquid and the polarity of the applied voltage. Show different characteristics. The physical constants related to the properties of the electrical insulating liquid are as shown in FIG.
[0025]
FIG. 5 shows the relationship between the flow velocity U and the applied voltage V. These velocities are measured at a point 1 mm on the central axis Z of the electrode system 10 from the upper tip of the pseudo donut-shaped electrode 1. The flow of BCRA and Tr-Oil is always sprayed upward from the flat electrode 2 side through the liquid flow hole 5a of the pseudo donut-like electrode 1 regardless of the polarity of the applied voltage, and the flow of DBDN and FS-Oil is applied. It was confirmed that it changed depending on the polarity of the voltage. As is apparent from FIG. 5, BCRA and DBDN exhibit a large flow rate for a given applied voltage, and BCRA particularly exhibits a large flow rate. Therefore, when utilizing a liquid jet by EHD pumping, it is useful to use BCRA or DBDN as the electrically insulating liquid.
[0026]
FIG. 6 shows the relationship between the pumping pressure P and the applied voltage V. As is apparent from FIG. 6, BCRA and DBDN generate a large pumping pressure for a given applied voltage, and the pumping pressure P changes in proportion to the square of the applied voltage V. Therefore, also from this characteristic, it is useful to use BCRA or DBDN as the electrically insulating liquid when utilizing a liquid jet by EHD pumping.
[0027]
In the case of an electrode system as shown in FIG. 1 in which no nozzle is provided, the liquid jet ejected upward through the liquid flow hole 1 a of the pseudo-doughnut-like electrode 1 becomes turbulent as it moves away from the tip of the pseudo-doughnut-like electrode 1. It becomes impossible to maintain a linear flow because it contains components. Therefore, in order to obtain a liquid jet having higher convergence and directivity, the electrode system 10 in which the nozzle 25 shown in FIG. 2 or the spiral nozzle 35 shown in FIG. 3 is added to the pseudo-doughnut-shaped electrode 1 is used. 7 and 8, the effect of adding these nozzles 25 and spiral nozzles 35 is prominent.
[0028]
That is, FIG. 7 shows the velocity distribution measured from the tip of the nozzle to the upper 25 mm along the central axis Z of the electrode system 10, and the maximum velocity is normalized to 1.0. FIG. 8 shows the velocity distribution measured in the radial direction at a position 20 mm above the tip of the nozzle. 7 and FIG. 8, an electrode system having no nozzle (the electrode system shown in FIG. 1), an electrode system having an ordinary nozzle (the electrode system shown in FIG. 2), and a spiral nozzle are provided. This is a comparison of the electrode system (the electrode system shown in FIG. 3).
[0029]
As shown in FIG. 7, as the measurement point moves away from the electrode system, a difference due to the difference in the electrode system appears. That is, the electrode system having a spiral nozzle has a small velocity attenuation rate even at a point away from the tip, and the directivity of the liquid jet is the best as compared with other electrode systems. In addition, FIG. 8 shows that the liquid jet of the electrode system having a spiral nozzle has the best convergence compared to other electrode systems.
[0030]
【The invention's effect】
As is clear from the above embodiments, according to the present invention, a positive or negative DC high voltage is applied to the electrode system in which the pseudo-doughnut-like electrode and the flat plate electrode are opposed to each other, so that an electrically insulating liquid at a constant temperature is obtained. In particular, a highly directional liquid jet can be generated, and since there is no charge injection from the electrode into the electrically insulating liquid, deterioration of the electrically insulating liquid used is suppressed, which is extremely effective in practice.
[0031]
On top of that, a converging property and directivity of the liquid jet can be further enhanced by constructing an electrode system by additionally connecting a pseudo donut-like electrode with a nozzle, particularly a spiral nozzle. Also, by using BCRA or DBDN as the electrically insulating liquid, good results can be obtained as the characteristics of the liquid jet.
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram of an apparatus for generating a liquid jet by EHD pumping according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of an apparatus for generating a liquid jet by EHD pumping according to another embodiment of the present invention.
FIG. 3 is a configuration diagram of an apparatus for generating a liquid jet by EHD pumping according to another embodiment of the present invention.
FIG. 4 is a characteristic explanatory diagram showing physical constants of an electrically insulating liquid used in the method and apparatus for generating a liquid jet by EHD of the present invention.
FIG. 5 is a relationship diagram between an applied voltage and a liquid jet flow velocity based on an experimental result of the present invention.
FIG. 6 is a relationship diagram between applied voltage and pumping pressure based on the experimental results of the present invention.
FIG. 7 is a characteristic diagram of the axial velocity of a fluid jet based on the experimental results of the present invention.
FIG. 8 is a characteristic diagram of radial velocity of a fluid jet based on the experimental results of the present invention.
[Explanation of symbols]
1: Pseudo-doughnut-shaped electrode 1a: Liquid flow hole 2: Plate electrode 3: Electric insulating liquid 4: DC high voltage power supply 10: Electrode system 25: Nozzle 25a: Conical liquid flow hole 35: Spiral nozzle 35a: Restriction Conical liquid flow hole 35b: Large root diameter portion 36: Auxiliary liquid passage 37: Auxiliary ring electrode 38: Auxiliary plate electrode 39: Cylindrical guide body 40: Guide groove (annular slit)
41: Small hole d: Gap R: Arc s: Gap Z: Center axis

Claims (6)

  One end of a pseudo-doughnut-like electrode having a circular or cylindrical shape with a liquid flow hole penetrating in the direction of the central axis and having both end faces formed in a smooth arc shape is opposed to the flat plate electrode with a gap therebetween, and the pseudo-doughnut A conical liquid flow hole connected coaxially with the liquid flow hole of the electrode and an auxiliary for introducing a liquid flow having a flow component perpendicular to the central axis direction into the root large diameter portion of the conical liquid flow hole A spiral nozzle having a liquid flow passage is coupled to the other end of the pseudo-doughnut-like electrode, and an auxiliary ring electrode is disposed around the inlet of the auxiliary liquid flow passage, and the auxiliary ring electrode is assisted through a gap. There are few electrode systems including a portion where the pseudo donut-like electrode and the flat plate electrode face each other, and a portion where the auxiliary ring electrode and the auxiliary flat plate electrode face each other. In addition, by placing a part in an electrically insulating liquid and simultaneously applying a DC high voltage between the pseudo-doughnut-like electrode and the flat plate electrode and between the auxiliary ring electrode and the auxiliary flat-plate electrode, A method of generating a liquid jet by EHD pumping, characterized in that the electrically insulating liquid is ejected from the tip of the spiral nozzle through a liquid flow hole of an electrode. 2. The method of generating a liquid jet by EHD pumping according to claim 1, wherein diethylene glycol monobutyl ether acetate is used as the electrically insulating liquid. The method for generating a liquid jet by EHD pumping according to claim 1, wherein n-butyl dodecanedioate is used as the electrically insulating liquid. A pseudo-doughnut-shaped electrode having a liquid circulation hole passing through in the direction of the central axis or having a circular arc shape at both ends thereof and a flat plate electrode opposed to one end of the pseudo-doughnut-shaped electrode with a gap And a conical liquid flow hole that is concentrically connected to the liquid flow hole of the pseudo-doughnut-shaped electrode and a liquid flow having a flow component perpendicular to the central axis direction is passed through the conical liquid flow hole. A spiral nozzle formed in the auxiliary liquid flow passage to be introduced into the base large diameter portion and coupled to the other end of the pseudo-doughnut-shaped electrode, an auxiliary ring electrode disposed around the inlet of the auxiliary liquid flow passage, An auxiliary plate electrode opposed to the auxiliary ring electrode with a gap, at least a portion of the pseudo-doughnut-like electrode and the plate electrode facing each other, and a portion of the auxiliary ring electrode and the auxiliary plate electrode opposed to each other And an electrode system in which a DC high voltage is simultaneously applied between the pseudo-doughnut-like electrode and the flat plate electrode and between the auxiliary ring electrode and the auxiliary flat plate electrode. A short cylindrical guide body is arranged inside the inner peripheral wall of the base large diameter portion of the nozzle conical liquid flow hole of the nozzle, and the liquid is drawn between the cylindrical guide body and the base large diameter portion. A guide groove that is urged toward the center of the hole is formed, a small hole that communicates with the guide groove from the outer peripheral surface of the spiral nozzle is provided, and an auxiliary liquid passage is formed by the guide groove and the small hole. A liquid jet generator using EHD pumping. The apparatus for generating a liquid jet by EHD pumping according to claim 4, wherein the electrically insulating liquid is diethylene glycol monobutyl ether acetate. 5. The liquid jet generator by EHD pumping according to claim 4, wherein the electrically insulating liquid is dodecanedioic acid-n-butyl.

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