阅读说明：本技术 一种基于电场增强结构的静电雾化喷嘴及其系统 (Electrostatic atomization nozzle based on electric field enhancement structure and system thereof ) 是由 霍元平 马登辉 张聪 王军锋 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种基于电场增强结构的静电雾化喷嘴及其系统,正多边体结构的喷嘴主体,喷嘴主体的一端为喷射端,另一端为注液端；喷射端的端面为附着面,喷射端处相邻喷嘴外壁面之间的棱角是喷嘴尖端；在喷射端的每一个喷嘴外壁面上均沿轴向设有液体明渠,液体明渠的底端延伸至附着面,每个液体明渠的顶端都设有出液口；由注液端向喷嘴主体内部沿轴向设有注液腔；注液腔的底部通过出液口与喷嘴主体外部相连通；所述喷嘴主体连接高压发生器；由于喷嘴尖端电荷密度集中,因此在每个喷嘴尖端产生射流；因此可以增加雾化流量同时可获得单分散性良好、射流区域广的雾化液滴。(The invention discloses an electrostatic atomization nozzle based on an electric field enhancement structure and a system thereof, wherein the electrostatic atomization nozzle is a nozzle main body with a regular polygon structure, one end of the nozzle main body is a spraying end, and the other end of the nozzle main body is a liquid injection end; the end surface of the spraying end is an attachment surface, and the edge angle between the outer wall surfaces of adjacent nozzles at the spraying end is a nozzle tip; liquid open channels are axially arranged on the outer wall surface of each nozzle of the spraying end, the bottom ends of the liquid open channels extend to the attachment surface, and a liquid outlet is arranged at the top end of each liquid open channel; a liquid injection cavity is axially arranged from the liquid injection end to the interior of the nozzle main body; the bottom of the liquid injection cavity is communicated with the outside of the nozzle main body through a liquid outlet; the nozzle main body is connected with a high-pressure generator; a jet is generated at each nozzle tip due to the concentration of nozzle tip charge density; therefore, the atomization flow can be increased, and atomized liquid drops with good monodispersity and wide jet flow area can be obtained.)

1. The electrostatic atomization nozzle based on the electric field enhancement structure is characterized by comprising a nozzle main body (5), wherein the nozzle main body (5) is of a regular polygonal structure, one end of the nozzle main body (5) is a spraying end, and the other end of the nozzle main body is a liquid injection end; the end surface of the spraying end is an attachment surface (17), and the edge angle between the adjacent outer wall surfaces (4) of the nozzle at the spraying end is a nozzle tip (1); each nozzle outer wall surface (4) of the spraying end is provided with a liquid open channel (2) along the axial direction, the bottom end of each liquid open channel (2) extends to an attachment surface (17), and the top end of each liquid open channel (2) is provided with a liquid outlet (3); a liquid injection cavity (8) is arranged from the liquid injection end to the inner part of the nozzle main body (5) along the axial direction; the bottom of the liquid injection cavity (8) is communicated with the outside of the nozzle main body (5) through the liquid outlet (3); the nozzle body (5) is connected with a high-pressure generator (12).

2. An electrostatic atomizing nozzle based on electric field enhancement structure according to claim 1, wherein the liquid channel (2) is disposed along the axial centerline of the outer wall surface (4) of the nozzle.

3. An electrostatic atomizing nozzle based on an electric field enhancement structure as set forth in claim 1, wherein the cross-sectional shape of the liquid channel (2) is designed as an arc-shaped groove or a regular polygonal groove.

4. An electrostatic atomizing nozzle based on electric field enhancement structure according to claim 1, characterized in that the length of the liquid channel (2)L₀Is the length of the nozzle body (5).

5. An electrostatic atomizing nozzle based on an electric-field-enhancement structure, as claimed in any one of claims 1 to 4, wherein the cross-sectional shape of the liquid outlet (3) is circular or polygonal.

6. An electrostatic atomizing nozzle based on electric field enhancement structure as set forth in claim 5, characterized in that said nozzle body (5) is made of metal material or alloy material.

7. An electrostatic atomizing system equipped with the electrostatic atomizing nozzle based on the electric field enhancement structure as set forth in claim 6, characterized by comprising a nozzle main body (5), wherein the liquid injection end of the nozzle main body (5) is connected to a micro-injection pump (9) through a liquid transfer tube (16), and the liquid to be atomized is pumped into the nozzle main body (5) by the micro-injection pump (9); the nozzle body (5) is connected to a high voltage generator (12) so that the nozzle body (5) is charged and a jet (7) is generated at each nozzle tip (1) due to the concentration of the charge density at the nozzle tip (1).

8. An electrostatic atomizing system using an electric-field-enhancement structure, as set forth in claim 7, wherein the output terminal of the high-voltage generator (12) is connected to the nozzle body (5) through a wire (13), and the ground terminal of the high-voltage generator (12) is connected to the ground (14) through the wire (13).

9. An electrostatic atomizing system using an electric-field-enhancement structure, as set forth in claim 7, wherein a collecting electrode (15) is provided directly under the nozzle body (5), the height between the collecting electrode (15) and the nozzle body (5) may be 10-80mm, and the collecting electrode (15) is made of a conductor of a metallic material or an alloy.

Technical Field

The invention belongs to the field of electrostatic atomization, and particularly relates to an electrostatic atomization nozzle based on an electric field enhancement structure and a system thereof.

Background

The electrostatic atomization technology is a method for realizing liquid crushing and atomization by utilizing the electrostatic action of a high-voltage electric field. The specific principle is that when charged liquid flows out from a nozzle opening, electrostatic shearing stress acts on the liquid surface to overcome the surface tension and viscous force of the liquid, so that the instability of the liquid surface is promoted to grow, and initial liquid drops are deformed and broken into smaller sub-liquid drops. Because electrostatic atomization can obtain a large amount of charged micro-droplets with fine particle size, good monodispersity, strong controllability and high deposition rate with low energy consumption, the electrostatic atomization method has great application value in the fields of ultra-low pesticide spraying, micro-nano film preparation, micro combustion, micro spray cooling, drug encapsulation, micro power propulsion, biological mass spectrometry and the like. At present, most of existing electrostatic atomization nozzles operate in a cone jet mode, the nozzles can only emit one jet flow in the mode, the size of liquid drops is strictly limited by supply flow, the atomization flow cannot be further improved, and the requirements of actual application in multiple fields of electrostatic atomization are difficult to meet.

The current methods for increasing the electrostatic atomization flow mainly include two methods: the flow rate is multiplied by an array of integrated single capillary nozzles or by a multi-jet mode of electrostatic atomization. In the former method, the nozzles are arranged in a linear or array manner, and the number of the nozzles is overlapped to improve the atomization flow, but the requirement on a high laser etching method and the processing cost is high, and the deposition uniformity of the whole spray is influenced due to the mutual interference between adjacent sprays in the simultaneous operation process; the multi-jet mode can be regarded as that a plurality of single-cone jets at the outlet of the nozzle are combined for atomization so as to improve the atomization flow, and the mode can be obtained at higher charge voltage. However, under the multi-jet mode, single jet can generate violent swing and is difficult to keep stable, the monodispersity of atomized liquid drops is influenced, meanwhile, over-high atomization voltage is easy to generate corona discharge, and the long-term stable operation of equipment cannot be guaranteed. Therefore, the above limitations of the method for increasing the atomization flow rate make it difficult to achieve large-scale popularization and application of electrostatic atomization in multiple fields.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides an electrostatic atomization nozzle based on an electric field enhancement structure and a system thereof.

The technical scheme adopted by the invention is as follows:

an electrostatic atomization nozzle based on an electric field enhancement structure comprises a nozzle main body, wherein the nozzle main body is of a regular polygonal structure, one end of the nozzle main body is a spraying end, and the other end of the nozzle main body is a liquid injection end; the end surface of the spraying end is an attachment surface, and the edge angle between the outer wall surfaces of adjacent nozzles at the spraying end is a nozzle tip; liquid open channels are axially arranged on the outer wall surface of each nozzle of the spraying end, the bottom ends of the liquid open channels extend to the attachment surface, and a liquid outlet is arranged at the top end of each liquid open channel; a liquid injection cavity is axially arranged from the liquid injection end to the interior of the nozzle main body; the bottom of the liquid injection cavity is communicated with the outside of the nozzle main body through a liquid outlet; the nozzle body is connected with a high pressure generator.

Further, the liquid channel is provided along the axial median line of the outer wall surface of the nozzle.

Further, the cross section of the liquid open channel is designed into an arc groove or a regular polygon groove.

Further, the cross-sectional shape of the liquid outlet is circular or polygonal.

Further, the length of the liquid open channelL₀Is the length of the nozzle body.

Further, the nozzle body is made of a metal material or an alloy material.

An electrostatic atomization system applying an electric field enhancement structure comprises a nozzle main body, wherein a liquid injection end of the nozzle main body is connected with a micro-injection pump through a liquid conveying pipe, and liquid to be atomized is pumped into the nozzle main body through the micro-injection pump; the nozzle body is connected to a high voltage generator to charge the nozzle body, creating a jet at each nozzle tip due to the concentration of the nozzle tip charge density.

Furthermore, the output end of the high-voltage generator is connected with the nozzle main body through a lead, and the grounding end of the high-voltage generator is connected with the ground pole through a lead.

Further, a collecting electrode is arranged right below the nozzle body, the height between the collecting electrode and the nozzle body can be 10-80mm, and the collecting electrode is made of a conductor made of a metal material or an alloy.

The invention has the beneficial effects that:

1. the invention relates to an electrostatic atomization nozzle based on an electric field enhancement structure, wherein the outer part of a nozzle main body is of a regular polygon structure, so that a plurality of edges are arranged at the bottom of an injection end, and a nozzle tip is formed at each edge during working, so that the tip structure is beneficial to increasing the local charge density, and a plurality of jet flows are more easily generated; meanwhile, the change of the position and the number of the tips of the nozzles can guide the change of the spraying direction and the adjustment of the number of the jet flows, thereby realizing the accurate control of the atomizing area and the reduction of the atomizing voltage.

2. Traditional flat-bottom capillary nozzle is at electrostatic atomization's in-process, the liquid that the nozzle opening flows can suck-back attached at the capillary outer wall, receive gravity and fall into the meniscus after falling down, lead to the fluidic flow sudden change of a certain share, the atress is unbalanced, the atomizing stability has been destroyed, and the electrostatic atomization nozzle of this application electric field enhancement structure is in service, treat that atomized liquid flows in order along liquid open channel, can not produce the sudden change of velocity of flow and flow, the terminal liquid level fluctuation of nozzle and fluidic instability have effectively been suppressed.

3. Like figure 8 tradition flat-bottom capillary nozzle after pipe diameter and flow promote, the axial and radial disturbance of meniscus appears very easily among the electrostatic atomization process, lead to efflux position transfer and efflux clearance to spray, and the bottom of the electrostatic atomization nozzle of this application electric field enhancement structure seals and forms terminal adhesion surface, has promoted the adsorption efficiency of nozzle tip to liquid, has restrained the axial disturbance of liquid level, makes big liquid cone shrink flat formation liquid film more easily, has strengthened the stability of stranded efflux.

4. According to the traditional flat-bottom capillary, all jet flow can be emitted from the edge of the outer end of a capillary needle in a charged multi-jet flow mode, but the wall of a capillary nozzle tube is thin, the attachment area of a small liquid cone is small, the capability of resisting liquid level fluctuation and external disturbance is weak, and the stable voltage interval is small. And under the electrostatic atomization nozzle of this application electric field enhancement structure, little liquid awl can be attached on terminal plane, and attached area improves by a wide margin, and every fluidic adhesive force increases, and the efflux shifts and obtains the suppression, and the steady voltage interval is showing and is promoting.

5. The electrostatic atomization nozzle with the electric field enhancement structure can stably operate in a multi-strand jet mode, the supply flow of the capillary tube is increased in multiples, the array integration of the capillary tube nozzle is not needed, and the processing difficulty and cost are reduced; the size of the liquid drop generated by each jet under the stable multi-jet is several times smaller than that of the cone jet under the same flow, so that the particle size of the atomized liquid drop is greatly reduced, and the atomization quality is improved; the jet atomization area is large and the angle is wide.

Drawings

FIG. 1 is a schematic structural view of an electrostatically atomizing nozzle in accordance with the present invention;

FIG. 2 is a top view of an electrostatic atomizing nozzle of the present invention;

FIG. 3 is an enlarged view of a portion of the exit port of the present invention;

FIG. 4 is an enlarged partial view of the liquid channel of the present invention;

FIG. 5 is a bottom view of an electrostatic atomizing nozzle of the present invention;

FIG. 6 is an electrostatic atomization system of the present invention;

FIG. 7 is a schematic illustration of an electrostatic atomization process of the present invention;

FIG. 8 is a schematic diagram of liquid level fluctuation during atomization with a conventional flat bottom nozzle;

in the figure, 1, a nozzle tip, 2, a liquid open channel, 3, a liquid outlet, 4, a nozzle outer wall surface, 5, a nozzle main body, 6, a liquid injection port, 7, jet flow, 8, a liquid injection cavity, 9, a micro-injection pump, 10, an injector, 11, a three-dimensional lifting platform, 12, a high-voltage generator, 13, a lead, 14, a ground pole, 15, a collecting electrode, 16, a liquid conveying pipe, 17 and an attachment surface;

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1 to 4, an electrostatic atomizing nozzle based on an electric field enhancement structure comprises a nozzle body 5, wherein the nozzle body 5 is a regular polygonal structure, that is, an outer wall surface of the nozzle body 5 is formed by a plurality of identical nozzle outer wall surfaces 4, one end of the nozzle body 5 is a spraying end, and the other end of the nozzle body 5 is a liquid injection end. In the present embodiment, the material of the nozzle body 5 is a conductor made of a metal material or an alloy, such as copper or stainless steel.

The end surface of the spraying end of the nozzle main body 5 is an attachment surface 17, and the edge angle between the adjacent nozzle outer wall surfaces 4 of the spraying end is a nozzle tip 1; each nozzle outer wall surface 4 of the spraying end is provided with a liquid open channel 2 along the axial direction, the bottom end of the liquid open channel 2 extends to an attachment surface 17, the top end of each liquid open channel 2 is provided with a liquid outlet 3, and the cross section of each liquid outlet 3 can be circular or polygonal; more specifically, the liquid channel 2 is disposed along the axial median line of the nozzle outer wall surface 4, and the cross-sectional shape of the liquid channel 2 may be designed as a semicircular groove or a regular polygonal groove designed radially inward, and the liquid channel 2 is a triangular groove as shown in fig. 5; while the length of the liquid open channel 2L₀Is the length of the nozzle body 5;

the end surface of the liquid injection end of the nozzle main body 5 is a liquid injection port 6, and a liquid injection cavity 8 is axially arranged from the liquid injection port 6 to the inside of the nozzle main body 5; the liquid injection chamber 8 can be a regular polygon chamber similar to the nozzle body 5 or a cylindrical chamber; and the liquid charging chamber 8 is provided coaxially with the nozzle main body 5. The bottom of the liquid injection cavity 8 is communicated with the outside of the nozzle main body 5 through the liquid outlet 3; the nozzle body 5 is connected to a high voltage generator 12 so that the charge density at the nozzle tip 1 of the nozzle body 5 is relatively concentrated and a jet 7 is formed at the nozzle tip 1.

Fig. 6 shows an electrostatic atomization system using an electric field enhancement structure, which includes a nozzle body 5, wherein a liquid injection end of the nozzle body 5 is connected to a micro-injection pump 9 through a liquid transport tube 16, and a liquid to be atomized is pumped into the nozzle body 5 by the micro-injection pump 9; the nozzle main body 5 is connected with a high-voltage generator 12, so that the nozzle main body 5 is electrified, and liquid to be atomized generates jet flow 7 at the edge of the spraying end of the nozzle main body 5; the output end of the high voltage generator 12 is connected with the nozzle main body 5 through a lead 13, and the grounding end is connected with a grounding pole 14 through a lead; in this embodiment, a syringe 10 is used in conjunction with a micro-syringe pump 9; the nozzle body 5 is arranged on a three-dimensional lifting platform 11, a collecting electrode 15 is arranged at a position 10-80mm under the nozzle body 5, the collecting electrode 15 can be made of a conductor made of a metal material or an alloy, such as red copper and stainless steel, and the collecting electrode 15 is connected with a ground electrode 14 through a lead 13.

The working process of the electrostatic atomizing nozzle based on the electric field enhancement structure and the electrostatic atomizing system shown in fig. 6 is further described as follows:

in this case, the nozzle body 5 is a regular hexagon, so the nozzle body 5 has 6 nozzle outer wall surfaces 4, and each nozzle outer wall surface 4 is provided with a liquid open channel 2; liquid to be atomized, such as ethanol, is used as an atomization working medium, the ethanol is loaded into the injector 10, the nozzle main body 5 is positioned 15mm above the collecting electrode 15 by controlling the three-dimensional lifting platform 11, and the flow of the micro-injection pump 9 is adjusted to 30 mL/h. The liquid to be atomized enters the nozzle main body 5 from the liquid injection port 6 through the liquid conveying pipe 16, then flows out from the 6 liquid outlets 3 on the outer wall surface 4 of the nozzle, is distributed to the attachment surface 17 along the liquid open channel 2, accumulates and falls under the gravity, and presents a drop-shaped mode.

The negative high voltage generator 12 is started and the voltage is gradually increased, the dropping speed of the liquid drops is increased, then the mode is switched to the cone jet mode, the voltage is continuously increased to 12.21kV, the large liquid cone gradually shrinks and is flat, and jet flow 7 is generated at the nozzle tip 1 with more concentrated charge density to form stable six jet flows, as shown in fig. 7. Because the liquid level is not fluctuated in a stable multistrand mode, and the jet flow 7 is absolutely stable, a large amount of charged micro-droplets with fine particle size, good monodispersity, strong controllability and high deposition rate can be continuously obtained.

In the whole process, the atomized liquid flows orderly along the liquid open channel 2 without sudden change of flow speed and flow; the attachment surface 17 effectively inhibits the up-and-down jumping of the liquid level to enhance the adsorption force of the liquid surface, and the large liquid cone is easier to shrink and flatten to form a liquid film, thereby reducing the fluctuation and the instability of jet flow of the liquid level; meanwhile, the small liquid cone can be attached to the attachment surface 17, the attachment area is greatly increased, the adhesion force of each jet is increased, and jet transfer is restrained, so that the electrostatic atomization is guaranteed to operate in a stable multi-jet mode.

The above embodiments are only used for illustrating the design idea and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the content of the present invention and implement the present invention accordingly, and the protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes and modifications made in accordance with the principles and concepts disclosed herein are intended to be included within the scope of the present invention.