JP5080789B2 - Nozzle device and method for forming atomization mechanism thereof - Google Patents

Description

  The present invention relates to a nozzle device that atomizes a liquid using gas as an energy source (air assist atomizer), and more specifically, stabilizes the “average particle diameter”, increases the “number of droplets generated”, and “spray angle”. And for the purpose of adjusting the "average flight distance of droplets", by forming a closed region surrounded by a gas jet downstream of the gas nozzle, and generating a low-pressure vortex region near the discharge port of the liquid nozzle, The present invention relates to a useful nozzle device that promotes liquid ejection and facilitates the transfer of energy from gas to liquid by using liquid nozzles having various irregular cross sections, thereby contributing to improvement in atomization efficiency.

In general, in a nozzle device (a spray lubrication device), as shown in FIG. 5, the liquid nozzle 1 and the gas nozzle 2 (air nozzle) are arranged concentrically (see FIG. 5 (a)) or crossed. (See Fig. 5 (b)), so-called venturi mechanism that utilizes the flow of compressed air to atomize the oil (lubricant or cutting agent), so that the axis of oil drops from above by passing a narrow venturi conduit compressed air from the air inlet 2a ₁ which is formed in a direction or in a radial direction (further using the negative pressure generated by strengthening the flow rate), thereby promoting the mixing of oil with the compressed air Oil mist (fog) is generated.

Conventionally, as such a nozzle device, for example, a liquid tank (tank) for storing lubricating oil, and an atomizer for atomizing the lubricating oil, the oil fog generated by the atomizer is used as a predetermined portion to be lubricated. An atomizing chamber to be fed to the first pipe, one end connected to the atomizer, the other end connected to a predetermined air supply means, one end connected to the tank, and the other end via a pump And a second pipe connected to the first pipe, and the oil level of the lubricating oil supplied from the second pipe into the first pipe is equalized to the air flow supplied from the air supply circuit. In the spray lubrication apparatus that collects the coarse particles of the atomized oil mist guided to the atomizer in the atomization chamber and feeds the fine particles to the lubricated part, The first pipe has a third pipe having one end connected to the atomization chamber, and the air flow of the air supply means Nozzle device is devised in which a suction means to achieve the venturi effect Ri (for example, see Patent Document 1).
JP 2002-349789 A

  However, in the above-described conventional nozzle device, the lubricating oil (liquid) is sucked from the liquid tank by the so-called venturi effect caused by the air flow (gas), and the lubricating oil (liquid) is mainly generated by the momentum of the air flow (gas). The atomization is realized by blowing away the gas, but this type of atomization method is intended to crush the liquid exclusively by the impulse of the gas, so the energy conversion efficiency from gas to liquid However, the generated droplets are not sufficiently refined and have a characteristic of being widely distributed around a relatively large average particle diameter.

  The present invention has been made in view of such conventional problems, and by generating a closed region by a gas jet downstream of the gas nozzle and generating a low-pressure vortex region in the vicinity of the discharge port of the liquid nozzle, By adopting a liquid nozzle that promotes the liquid jet power and increases the contact area between the gas and the liquid, the energy transfer from the gas to the liquid is facilitated, and the turbulent shear force generated by the gas actively It is an object of the present invention to provide a useful nozzle device that promotes a general atomization process and realizes formation of finer droplets.

In order to solve the conventional problems as described above and achieve the intended purpose, the gist of the nozzle device according to the present invention is at least one or more air inlets formed in the radial direction and air that ejects air in an annular shape. A nozzle device comprising: a gas nozzle having an introduction path; and a liquid nozzle arranged concentrically with the gas nozzle to supply a liquid, wherein the gas nozzle is at a predetermined angle with respect to the axis of the liquid nozzle. inclined are those comprising a atomization mechanism allowed to generate a low-pressure vortex region downstream of the fluid nozzle, the atomization mechanism, the apex of the reference cones in any position on the axis X ₁ -X ₁ of the liquid nozzle Is selected, the apex angle α is determined at the apex of the reference cone to determine the base line of the reference cone, and then the base circle diameter D ₀₁ is selected to be orthogonal to the generatrix at the position of the base circle of the reference cone Draw a straight line and use this as the back cone bus The axes intersection on heart X ₁ -X ₁ is a vertex of the back cone, it selects a flow path cone angle θ be selected vertex of the passage cone on generatrix of the back cone, the vertex of the back cone set is intended to be formed by determining the back length Y _2, the gas nozzle by the atomization mechanism comprises a tapered annular bore whose diameter decreases along θ the passage cone angle downward, the annular impinging on the axis X ₁ -X ₁ of the liquid nozzle turbulent jets emitted by the closed region is formed inside the turbulent jets is to allowed to generate the low-pressure vortex region.

Further, the gist of the atomization mechanism forming method of the nozzle device according to the present invention is a gas nozzle having at least one or more air inlets formed in the radial direction and an air introduction path for ejecting air in an annular shape. The atomization mechanism of the nozzle device comprising a liquid nozzle that is arranged concentrically with the gas nozzle and supplies the liquid has an apex of the reference cone at an arbitrary position on the axis X ₁ -X ₁ of the liquid nozzle. Is selected, the apex angle α is determined at the apex of the reference cone to determine the base line of the reference cone, and then the base circle diameter D ₀₁ is selected to be orthogonal to the generatrix at the position of the base circle of the reference cone This was a generatrix of the back cone pulling the straight, becomes the apex intersection of the back cone on the axis X ₁ -X _1, the flow path cone angle selected vertex of the passage cone on generatrix of the back cone select a theta, setback length Y ₂ from the top of the back cone It is formed by deciding.

The liquid nozzle includes a nozzle device having a polygonal channel cross section (including a composite polygonal shape and a petal shape) or a crystal-shaped channel cross section radially coupled via a small-diameter circular hole portion and a slit portion. To do.

The liquid nozzle has a flow path cross section of a polygonal shape (including a composite polygonal shape and a petal shape) or a crystal flow path cross section radially coupled via a small diameter circular hole portion and a slit portion. It is the atomization mechanism formation method of a nozzle apparatus.

The present invention is configured as described above, and the gas nozzle is provided with a atomization mechanism that is inclined at a predetermined angle with respect to the axis of the liquid nozzle and generates a turbulent jet on the downstream side of the liquid nozzle. The mechanism passes air through an annular flow path determined by an inclined surface formed on the outer peripheral surface of the liquid nozzle and an inclined surface of a tapered annular hole formed in the air introduction path so as to face the inclined surface. Injecting at an angle in the axial direction of the liquid nozzle, that is, the apex of the back cone angle β relative to the reference cone angle α of the air introduction path or the air introduction path on the axis X ₁ -X ₁ of the liquid nozzle By connecting the intersection P of the injection axes X ₂ -X ₂ , a high-speed and stable gas turbulent jet is generated downstream of the liquid nozzle, and a low-pressure vortex region is formed immediately downstream of the discharge outlet of the liquid nozzle. When it is generated, the liquid in the nozzle is forcibly added. The effect of speeding up and facilitating the transfer of energy from gas to liquid is achieved.

  In other words, the atomization mechanism of the present invention promotes the inflow of liquid by generating a low-pressure vortex region surrounded by the gas jet and the bottom surface of the liquid nozzle immediately downstream of the discharge port of the liquid nozzle, As will be described later, by selecting the shape of the cross section of the flow path of the liquid nozzle so as to ensure a larger contact area with the gas, the atomization of the liquid has further progressed, and the turbulence of the gas has sufficiently developed the liquid. The turbulent shear force brought about by contact with the stream jet makes it possible to produce finer droplets.

For this purpose, in the atomization mechanism of the present invention, the gas nozzle is an annular nozzle (through a tapered annular hole) that forms a flow channel cone having an apex downstream of the flow channel, and its injection axis X ₂ -X _2. it is to bear intersection P on the axis X ₁ -X ₁ of the liquid nozzle, preferably by also apex of the passage cone configured to share the point P, the injection axis X ₂ -X ₂ is a top As a result of the geometrical determination of the back cone angle β, which is perpendicular to the generatrix of the reference cone with the angle α and the diameter D ₀₁ (see FIG. 2), the flow field (low pressure vortex region) downstream of both the gas and liquid nozzles. : See FIG. 3), and the atomization process for generating finer and larger amount of droplets with high efficiency is realized.

  Further, the liquid nozzle has a polygonal channel cross section (including a composite polygon and a petal shape) or a crystal flow path cross section radially connected through a small diameter circular hole portion and a slit portion. For example, in the case of a crystal-shaped channel cross section, the transfer of energy between the gas and liquid is promoted by enclosing a plurality of thin liquid yarns or a thin liquid curtain around the gas, and the particle size is reduced. There is an effect that the number of generations can be increased to improve the liquid atomization efficiency.

  Further, the gas nozzle is formed in a primary air chamber that is recessed to allow the front end side of the liquid nozzle, and an axial center of the primary air chamber, and loosely fits the front end side of the liquid nozzle. A tapered annular hole and a secondary air chamber communicating with the primary air chamber via the tapered annular hole are provided, and the tapered annular hole cooperates with the inclined surface of the liquid nozzle to share the air. By ejecting at an angle in the axial direction of the liquid nozzle, a fixed wall (including the liquid surface filled in the liquid nozzle) and a closed region is formed immediately downstream of the discharge port of the liquid nozzle. The pressure in the closed region is negative with respect to the surrounding pressure due to the entrainment caused by the liquid, so even if the liquid is relatively viscous, the liquid remains in the state of a liquid column, liquid string or liquid curtain. Can be pulled out easily into the area, and within the closed area Out liquids to immediately caught in a gaseous jet impinging, cleaved by turbulent eddies that gas jet is generated, an effect such is efficiently miniaturized.

  On the other hand, since the annular gas jet has a collision effect, the momentum in the radial direction is canceled and only the momentum component in the axial direction is preserved, so that the coaxial jet having a virtual origin on the liquid nozzle axis is sufficiently downstream after the collision. As a result of the behavior, the diffusion angle of the gas jet is limited, enabling a rational design of the device that realizes the atomization of the liquid retained in it, improving the atomization efficiency, and also the droplet spraying It has the effect of making it possible to predict corners and flight distances.

A atomizing mechanism is formed in the gas nozzle that is inclined at a predetermined angle with respect to the axis of the liquid nozzle and generates a turbulent jet on the downstream side of the liquid nozzle. The atomization mechanism has an annular flow path determined by an inclined surface formed on the outer peripheral surface of the liquid nozzle and an inclined surface of a tapered annular hole formed in the air introduction path so as to face the inclined surface. Air is ejected at an angle to the axial center of the liquid nozzle. Further, the liquid nozzle is preferably a polygonal channel cross section (including a composite polygon or a petal shape) or a crystal flow channel cross section coupled by a small diameter circular hole portion and a slit portion. Furthermore, the gas nozzle has a primary air chamber that is recessed to allow the tip side of the liquid nozzle, and a taper that is formed in the axial center of the primary air chamber and loosely fits the leading edge of the liquid nozzle. An annular hole and a secondary air chamber communicated with the primary air chamber via the tapered annular hole, wherein the tapered annular hole cooperates with an inclined surface of the liquid nozzle to supply air to the liquid nozzle. the axis X ₁ -X is good allowed to ejected angled towards _1.

  Hereinafter, an example of implementation of the nozzle device according to the present invention will be described with reference to the drawings. In the drawing, A is a nozzle device according to the present invention. As shown in FIG. 1, the nozzle device A includes a liquid nozzle (needle nozzle) 1 having a liquid inflow hole 1 a in the axial direction, and the liquid nozzle 1. And a gas nozzle (air nozzle) 2 connected concentrically.

The liquid nozzle 1 includes a liquid inflow hole 1a penetrating in the axial direction and a needle portion 1b having an inclined surface 1b ₁ on the outer periphery of the tip. A square, petal or crystal shape is used.

The liquid inlet 1a is, for example, a large diameter portion 1a ₁ of the upper end side is expanded (diameter 7 mm) to 120 degrees, and diameter portion 1a ₂ in the inner diameter of 2 mm, the small diameter of the inner diameter 1.2mm communicating with the outlet side and a part 1a _3.

Furthermore, the needle unit 1b, to desired tapered annular hole 2c to be described later discharge opening of the small diameter portion 1a ₃ of the liquid inlet hole 1a, for example, the apex angle (hereinafter, simply referred to as a reference cone angle) alpha = 146 ° When the flow path cone angle θ = 4 degrees and the setback length (offset) y ₂ = 4 mm, the tip diameter is about 2.142 mm, and the inclination angle with respect to the axis X ₁ -X ₁ is 15 degrees. Has been processed.

Hereinafter, the atomization mechanism according to the present invention (determination of the flow path shape dimension) will be briefly described with reference to FIGS. First, the apex of the reference cone is selected at an arbitrary position on the base line (center line of the apparatus: axis) X ₁ -X ₁ , and the apex angle α (140 to 150 degrees: 146 degrees in this embodiment) is determined. Determine the generatrix of the reference cone.

Next, a base circle diameter D ₀₁ (refer to FIG. 2: 3.611 mm in this embodiment) is selected, and the position becomes the center diameter of the flow path inlet of the gas nozzle 2. Then, pull the straight line perpendicular to the generating line at the location of the base circle of the reference cones, this straight line becomes a generatrix of the back cone, the apex, of course, be present on the base shaft line (axis) X ₁ -X _1, The apex angle β of the back cone (hereinafter simply referred to as the back cone angle β) is uniquely determined (34 degrees in this embodiment). The position of the apex of the flow channel cone is selected on the drawn back cone generatrix (injection axis X ₂ -X ₂ ) (in this embodiment, coincides with the apex of the back cone).

Next, the channel cone angle θ (4 degrees in this embodiment) is selected. Finally, the setback length (offset) y ₂ (4 mm in this embodiment) is determined. As described above, all the shapes and dimensions forming the flow path of the atomization mechanism are determined (at this time, the back cone angle is 34 degrees, the inlet nozzle width for the gas is 0.430 mm, the outlet nozzle width is 0.288 mm, passing cross sectional area 4.879Mm ² at the inlet portion, the 2.187Mm ² at the outlet portion).

  On the other hand, the gas nozzle 2 includes a primary air chamber 2a that is recessed in a short cylindrical shape, and secondary air for storing air that communicates with the primary air chamber 2a via a tapered annular hole 2c described later. And a chamber 2b.

The primary air chamber 2a is recessed to allow the front end side of the liquid nozzle 1, and air inlets 2a ₁ and 2a ₁ are formed in the radial direction and are described later formed in the axial direction. A tapered annular hole 2c is connected to the air introduction path 2d.

The tapered annular hole 2c constitutes an air nozzle portion that generates a gas jet, and serves as an annular tapered nozzle that gradually decreases in diameter toward the bottom so as to allow the air chambers 2a and 2b to communicate with each other. the inclined surface 1b of the liquid nozzle 1 ₁ and cooperate to constitute a atomization mechanism.

Specifically, as described above, the back-cone angle β that determines the position of the air introduction path 2d is geometrically calculated from the reference cone angle α and the base circle diameter _D01. good to realize atomization characteristics should not base shaft line X ₁ -X ₁ and crossing angle beta / 2 spray axis X ₂ -X ₂ too large, the reference cone angle as generally less than 20 degrees It is desirable to select α.

In the nozzle device of this embodiment configured as described above, when air is ejected through the tapered annular hole 2c of the air introduction path 2d, the nozzle device 1b achieves the highest speed at the discharge port of the needle portion 1b, and the liquid is directed downstream. An annular turbulent jet that collides on the axis X ₁ -X _{1 of the} nozzle 1 is discharged.

  At this time, the jet flows downstream while entraining the surrounding gas. However, as shown in FIG. 3B, the gas jet flow is closed by the solid wall and the liquid filled in the liquid nozzle 1. The internal pressure Pb gradually becomes lower than the surrounding pressure P∞ due to the entrainment flow rate (volume flow rate) qe. In other words, as the fluid existing in the closed region decreases, the internal pressure becomes Since the pressure is reduced, the suction of the liquid is promoted using the differential pressure.

  Next, when a sufficiently developed turbulent jet is formed downstream of the gas nozzle 2 (in the secondary air chamber 2b), the diffusion angle θ of the jet is largely determined by the back cone angle (impact angle of the gas jet) β. In addition, the spray angle of the liquid particles held therein is similarly determined.

  In addition, since the flying distance of the droplet is governed by the gas jet and the initial velocity of the liquid, and the velocity of the liquid is largely determined by the pressure Pb in the closed region and the viscous force of the liquid, if the atomization phenomenon is steady The average flight distance of the droplets is also determined.

  Incidentally, the shape of the cross section of the flow path of the liquid nozzle 1 in the conventional nozzle device is almost circular (see FIG. 4A) 3, but a sufficiently developed turbulent jet is generated in the secondary air chamber 2b. In the case where the energy required for atomization is formed and supplied from the gas, the atomization of the liquid is promoted depending on the contact area between the gas and the liquid. Even if they are the same, as shown in FIGS. 4B to 4D, the liquid flow paths 4 and 6 having a polygonal cross section or the small diameter minute circular holes 5a, 5a. By adopting the crystal-shaped liquid flow path 5 that is bonded radially, the contact area with the gas can be increased.

  In other words, when the gas jet forms a sufficiently developed turbulent jet and the energy required for atomization is sufficiently supplied from the gas to the liquid, the atomization phenomenon depends on the contact area between the two. And promoted. In many cases, the flow path of the liquid nozzle in the conventional atomization apparatus has a circular cross section as shown in FIG. 4 (a), as shown in FIGS. 4 (b) to 4 (d). By adopting a simple cross-sectional shape, even if the cross-sectional area of the flow path is the same, the contact area between the two can be further increased. As a result, a stable atomization phenomenon is realized, and an improvement in atomization efficiency is realized through a reduction in average particle diameter and an increase in the number of droplets generated.

  Among the irregular cross-sectional shapes adopted as the flow path of the liquid nozzle 1, FIG. 4 (b) shows an example of a complex polygon, FIG. 4 (c) shows a petal shape, and FIG. 4 (d) shows an example of a crystal shape. In particular, in the case of the crystal-shaped liquid flow channel 5 in which a plurality of small-diameter circular holes 5a, 5a,... In a cross section are radially coupled by fine grooves (slits) 5b, 5b (FIG. 4 (d)). Makes it possible to form a plurality of thin liquid yarns and thin films in a gas jet, facilitating the transfer of energy between gas and liquid, and facilitating the refinement of the particle size and the increase in the number of droplets generated. Can be improved.

  The nozzle device of the present invention is not limited to this embodiment, and can be freely modified within the scope of the object of the present invention, and the present invention encompasses all of them. For example, the present invention is a diesel engine, a gasoline engine, a liquid combustion device, a coating device, a liquid spraying device containing agrochemicals, a medical atomizer, and the like. The invention can be applied to all devices and engines for atomization, and the present invention includes all of them.

It is a principal part longitudinal cross-sectional view of the nozzle apparatus which concerns on this invention. It is explanatory drawing of the parameter which prescribes | regulates the flow-path shape of the nozzle apparatus. It is explanatory drawing of the flow state in the composite nozzle discharge part vicinity of the same nozzle apparatus. FIG. 4 (a) is an explanatory view showing the cross-sectional shape (circular shape) of a conventional liquid nozzle, and FIG. 4 (b) is an explanatory view showing a first embodiment (composite polygon) of the liquid nozzle used in the present invention. FIG. 4 (c) is an explanatory view showing a second embodiment (petal shape) of the nozzle, and FIG. 4 (d) is an explanatory view showing a third embodiment (crystal form) of the nozzle. It is explanatory drawing which shows the nozzle structure (arrangement | positioning) in the conventional liquid atomization apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid nozzle 1a Liquid inflow hole 1a ₁ Large diameter part 1a ₂ Medium diameter part 1a ₃ Small diameter part 1b Needle part 1b ₁ Inclined surface 2 Gas nozzle 2a Primary air chamber 2a ₁ Air inlet 2b Secondary air chamber 2c Tapered ring Hole 2d Air introduction path 3 Circular liquid flow path 4 Petal-shaped (hexagonal) liquid flow path 5 Crystal-shaped liquid flow path 5a Circular hole part 5b Slit part 6 Compound polygonal (octagonal) liquid flow path

Claims (4)

A gas nozzle having at least one or more air inlets formed in a radial direction; an air introduction path for ejecting air in an annular shape; and a liquid nozzle arranged concentrically with the gas nozzle to supply a liquid. In the nozzle device
The gas nozzle includes a atomization mechanism that is inclined at a predetermined angle with respect to the axis of the liquid nozzle and generates a low-pressure vortex region on the downstream side of the liquid nozzle,
The atomization mechanism is
Selecting the apex of the reference cone at an arbitrary position on the axis X ₁ -X _{1 of the} liquid nozzle, determining the apex angle α at the apex of the reference cone, and determining the generatrix of the reference cone;
Next, a base circle diameter D ₀₁ is selected, and a straight line perpendicular to the generatrix is drawn at the position of the base circle of the reference cone to make it a generatrix of the dorsal cone,
The intersection point on the axis X ₁ -X ₁ is the apex of the back cone, the apex of the flow channel cone is selected on the generatrix of the back cone, the flow channel cone angle θ is selected, and the apex of the spine cone and those formed by determining the setback length Y _2,
Due to the atomization mechanism, the gas nozzle has a tapered annular hole whose diameter is reduced downward along the channel cone angle θ, and an annular turbulence that collides on the axis X ₁ -X _{1 of the} liquid nozzle. A flow jet is discharged and a closed region is formed inside the turbulent jet to generate the low-pressure vortex region;
Nozzle device characterized by. A gas nozzle having at least one or more air inlets formed in a radial direction; an air introduction path for ejecting air in an annular shape; and a liquid nozzle arranged concentrically with the gas nozzle to supply a liquid. The atomization mechanism of the nozzle device
  Liquid nozzle axis X ₁ -X ₁ Select the apex of the reference cone at an arbitrary position above, determine the apex angle α at the apex of the reference cone and determine the generatrix of the reference cone,
  Next, the base circle diameter D ₀₁ And draw a straight line perpendicular to the generatrix at the position of the base circle of the reference cone to make it a generatrix of the dorsal cone,
  Axis X ₁ -X ₁ The intersection at the top is the apex of the back cone, the apex of the flow channel cone is selected on the generatrix of the back cone, and the flow channel cone angle θ is selected,
  Setback length Y from the apex of the dorsal cone ₂ To be formed by deciding
    A method for forming a atomization mechanism of a nozzle device. The liquid nozzle has a polygonal (including complex polygon, petal-shaped) channel cross-section or a crystal-shaped channel cross-section radially coupled through a small-diameter circular hole and a slit,
  The nozzle device according to claim 1. The liquid nozzle has a polygonal (including complex polygon, petal-shaped) channel cross-section or a crystal-shaped channel cross-section radially coupled through a small-diameter circular hole and a slit,
  The method for forming a atomization mechanism of a nozzle device according to claim 2.

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