JP2002508242A - Fuel injection nozzle and method of using the same - Google Patents

Abstract

(57) A first fuel source comprising a formulation to be atomized on one side and a second fluid source contained in a pressure chamber at least surrounding an area to which the first liquid is supplied, From the two immiscible fluids, atomized particulates in the desired size range (eg, from 1 micron to about 5 microns) are produced. The second fluid is discharged from an orifice located in front of the flow path of the first fluid stream. The present invention provides a method for forming small, relatively uniform fuel particulates for use in an internal combustion engine, and a nozzle-type apparatus for supplying the particulates to a combustion chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

FIELD OF THE INVENTION The present invention relates generally to fuel injection devices, and more particularly, to fuel injection nozzles for use in internal combustion engines.

BACKGROUND OF THE INVENTION [0002] Various types of fuel injectors are known in the art, and these devices generally use a conventional fuel injection nozzle to introduce small droplets of fuel into a combustion chamber of an engine, This increases the effective fuel surface area involved in the reaction. As the surface area of the fuel increases, a more efficient combustion reaction is obtained in the internal combustion engine. Many improvements have been made to the fuel injection process of internal combustion engines,
Such fuel injection devices in fuel injection systems have become more efficient. For example, U.S. Patent No. A fuel injection device is disclosed. In this device, a direct line connection with the fuel supply line is avoided during an injection event, and pressure waves appearing in the line cannot influence the injection event. Another example is GB 2,099,078A, which describes the use of a dual rotary valve to control the timing and delay time to open the intensifier cavity for high pressure working fluid or low pressure fuel drain. ing. Yet another example is U.S. Pat. No. 5,697,341 which describes a hydraulically operated fuel injector in which a plunger driven by a booster piston presses fuel. Fuel in the hydraulically operated device is metered by biasing the plunger with a return spring, or by pressing the fuel between injection events and pushing the plunger in a retracting direction using hydraulic pressure and the injector. Can be supplied to While the quantity and quality of injection in fuel injectors has been improved by changing the fueling routes for methods and devices, these improvements have been
It essentially does not address the limitations in the efficiency of the nozzle mechanism. Each of the foregoing systems for improving fuel delivery uses conventional VOP-type needle closure valves and nozzles. An example of a conventional nozzle is U.S. Pat.
Nos. 338, 4,603,671 and 4,363,446. This type of conventional nozzle-based delivery method is technically related to the minimum size of the ejected fuel droplets, the amount of energy required to produce the fuel droplets, and clogging due to accumulation of fuel component residues. Has limitations. There is a need in the art for a more efficient method of injecting fuel into an internal combustion engine, for example, reducing the size of the fuel droplets to increase the surface area available for combustion reactions. That is, there is a need in the art for a nozzle that increases the fuel supply efficiency of a fuel injection system.

SUMMARY OF THE INVENTION [0003] A fuel injection nozzle for use in a fuel injection device for an internal combustion engine is provided. The fuel injection nozzle of the present invention has a unique fuel supply system consisting of a pressure chamber and a fuel source. Fine particles of fuel within the desired atomized size range (e.g., from 5 microns to about 500 microns, preferably from 10 to 100 microns) are generated from a liquid fuel formulation supplied through a fuel supply opening. . The fuel can be supplied in any desired manner, for example, by pushing it through the channel of the feeding needle and discharging it out of the outlet opening of the needle. At the same time, a second fluid contained in the pressure chamber surrounding at least the outlet of the needle, for example the fuel discharged from the feeding needle, e.g. Is pushed out of the opening arranged in front of the. Various parameters are adjusted to ensure a stable fuel-gas interface and a stable capillary jet of fuel, which allows for the formation of atomized fuel particulates as it exits the pressure chamber opening. The fuel injector of the present invention has three notable advantages over conventional injectors. First, the fuel does not come into contact with the periphery of the outlet orifice because the fuel stream is wrapped by gas (eg, air) flowing into the outlet orifice from which the fuel is discharged. As a result, clogging of the orifice is eliminated or substantially reduced. Second, the fuel exiting the orifice forms very small particulates that are substantially uniform in size, thereby enabling fast and more controlled combustion of the fuel. Third, by using the methods described herein, the amount of energy required to produce aerosolized particulates of the fuel is substantially less than that required by other methods. . One object of the present invention is to provide a device for efficiently supplying fuel to a combustion chamber of an internal combustion engine. It is another object of the present invention to provide a method for producing a fuel aerosol of unchanged particle size that increases the surface area available for combustion reactions. One feature of the present invention is that the diameter of the opening from which the fluid is discharged, the diameter of the opening from which the fluid is discharged, and the distance between these two openings are adjustable to obtain a stable fuel-fluid interface. As a result, the released fuel forms a stable capillary microjet, i.e., a microjet converged at the outlet opening by the flow of surrounding fluid (e.g., gas). One advantage of the present invention is that it produces constant fuel particulates having a desired range of particulate diameters. Another advantage of the present invention is that the method of aerosolizing the fuel is less prone to clogging of particulates when entering the combustion chamber. One advantage of the present invention is that fuel injection using the device of the present invention is energy efficient. Another advantage is that the structure of the device and its use are simple. Another advantage is that clogging of the outlet opening of the pressure chamber is substantially eliminated because the fluid wrapping the converging funnel and flowing out of the outlet opening of the pressure chamber causes fuel to be separated from the outlet opening surface. Yet another advantage is that the generated particulates are substantially smaller in size than would be expected based on the diameter of the outlet opening of the pressure chamber, since the flow of the fuel was converged by the enclosing fluid. is there. One aspect of the present invention is a fuel injection nozzle that is one element of a fuel injection device and system. Another aspect of the invention is a device that provides for quick start / stop of the aerosolization process. These and other aspects, objects, features and advantages will become apparent to those skilled in the art from a reading of this disclosure in connection with the following drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the devices and methods, the present invention is not limited to the particular elements and steps described herein, as such may, of course, vary. It is necessary to understand that It should also be understood that the terms in the description are used for the purpose of describing particular embodiments only, and are not intended to be limiting. Here, and in the claims, the singular forms “a” (the “a” in the indefinite article), “and” and “the” (the definite article) clearly indicate that It should be noted that unless otherwise indicated, multiple references are included. Thus, for example, reference to "a particle" includes a plurality of microparticles, and reference to "a pharmaceutical" refers to one or more pharmaceutical agents as well as those skilled in the art. Include its well-known equivalents, and so on. Unless defined otherwise, technical and scientific terms used herein have the same common understanding to a person of ordinary skill in the art to which this invention belongs. Although any methods, devices and materials similar or equivalent to those described can be used in the practice or testing of the present invention, the preferred methods, devices and materials are now described. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing contained herein is to be construed as an admission that the present invention does not have prior rights to this type of publication by virtue of prior invention. Furthermore, the date of the presented announcement may be different from the actual date of the announcement, and confirmation is required for each.

Definitions Here, the terms “particulates”, “atomized particulates” and “atomized formulation particulates” are used interchangeably and are described using the devices and methods of the present invention. Fine particles of the atomized formulation are meant. As used herein, the terms "formulation" and "fuel formulation" are used interchangeably and refer to any substance that one wishes to atomize. The formulation is any fluid used to initiate and / or participate in the combustion reaction, preferably a saturated aliphatic hydrocarbon, such as gasoline or kerosene. The formulation can be a second fluid in the method of the invention, but is preferably provided as the first fluid. The formulation can be a mixture of fuels in any form of a solution, suspension or emulsion. Herein, the terms "air", "air free of particulates" and similar terms are used to refer to any volume of air that is substantially free of other substances, especially particulates that are intentionally added, such as particulates of a formulation. Used interchangeably to describe air that does not contain.
These terms mean that air does not include particulates of the formulation that are intentionally added, but normal ambient air can be filtered or filtered or treated to remove all particulates It does not imply that. Air may be filtered for use in the present invention, or other gases may be used.

(Device Overview) The present invention can be applied to fine particle generation for various uses. The present disclosure focuses on the general techniques used to fuel internal combustion engines, such as, for example, positive displacement spark ignition engines. However, the present invention is not limited to the use related to the method and the device of the present invention, and can be applied as a fuel supply means such as a gas turbine, a burner, and a heater. And those skilled in the art will readily notice. The basic technology of the present invention comprises (1) means for supplying a first fluid; and (
2) Consists of a pressure chamber to which a second fluid is supplied. The first fluid is generally a liquid, preferably a hydrocarbon fuel comprising a saturated aliphatic hydrocarbon. The second fluid is generally a gas, preferably air or a hydrophilic liquid. An important property of the fluid is that the first and second fluids are sufficiently different from each other (immiscible) to form a suitable microjet of the first fluid extending from the supply means to the outlet port of the pressure chamber. Is to make it possible. Regardless of the difference between these gas-liquid, liquid-gas, and liquid-liquid combinations, the present invention provides a stable microjet that is released from the supply means, i.e., converges the microjet and exits from the outlet of the pressure chamber. It is generally described with a fluid formulation that forms a microjet that flows out and interacts with the surrounding airflow. The formation of the microjet and its acceleration, and the formation of the final particles,
Based on a sharp pressure reduction associated with a steep acceleration experienced by a first fluid (eg, a liquid) as it passes through an outlet orifice of a pressure chamber holding a second fluid. Upon exiting the chamber, the fluid experiences a specific pressure difference between a first fluid (eg, a liquid) and a second fluid (eg, a gas), which subsequently changes the pressure of the first fluid (eg, a liquid). A sharply curved zone is created on the surface near the outlet port of the chamber to form a cusp, so that the amount of first fluid (eg, liquid) extracted through the outlet port of the pressure chamber is replenished. And a stable micro jet is obtained. In other words, the gas flow envelops the liquid and converges it into a stable microjet in the same manner as a glass lens or eyeball lens focuses light at a given point. The effect of focusing by this surrounding gas flow produces a stream of liquid whose diameter is substantially smaller than the diameter of the outlet orifice of the pressure chamber. This allows liquid to flow out of the orifice of the pressure chamber without contacting the orifice, (1) substantially eliminating the plugging of the outlet orifice, (2) the object above the orifice opening. (3) stream and resulting particulates are smaller than the diameter of the chamber exit orifice, substantially eliminating flow contamination due to contact with (eg, unwanted particles); Benefits are provided, including: This is particularly desirable because it is difficult to accurately machine very small diameter holes. Furthermore, in the absence of a focusing effect (and a stable microjet), the flow of fluid exiting the aperture will be about twice as large as the diameter of the exit aperture. Another feature is that the fine particles after leaving the chamber have no tendency to agglomerate. Hereinafter, specific examples of the aerosol generation device will be described.

(Embodiment of FIG. 1) A first embodiment of the present invention will be described with reference to FIG. 1, in which a supply means is a cylindrical feeding needle for supplying a liquid into a gas pressure chamber. The components of the embodiment shown in FIG. 1 are as follows. 1. Feeding Needle-Also commonly referred to as fluid source and tube. 2. The end of the feeding needle used to insert the liquid to be atomized. 3. Pressure chamber. 4. Orifices used as gas inlets. 5. The end of the feeding needle used to drain the liquid to be atomized. 6. The orifice where the spill occurs. 7. Atomizing product (spray)-sometimes called an aerosol. D ₁ = feeding needle diameter; axial orifices e = outflow occurs length;; D ₀ = orifice microjet passes diameter distance from H = feeding needle to the outlet of the microjet; P ₀ = the pressure in the chamber; P _a = atmospheric pressure. The fuel injection nozzle of the present invention may have any size, but preferably has a size that can be used for a general fuel injection device. While the device of the present invention can be configured in a variety of designs, each design will include or essentially provide all of the basic components shown in FIG. It will include the components that result. In particular, the fuel injection nozzle of the present invention discharges at least one source of formulation (e.g., a feeding needle having an opening 2) capable of supplying a formulation of a flowable liquid and the formulation. Consists of an outlet opening 5 obtained. The feeding needle 1 or at least its outlet opening 5 is surrounded by a pressure chamber 3. The chamber 3 has an inlet opening 4 used to supply gas into the chamber 3 and an outlet from which a mixture of gas from the pressure chamber and liquid from the feeding needle 3 is released to form an aerosol. An opening 6 is provided. In FIG. 1, the feeding needle and pressure chamber are configured to achieve the desired result of small and uniform particle size in aerosol generation. Preferably, the microparticles have a size in the range of 0.5 to 500 microns, and more preferably, have a size in the range of 10 to 100 microns. Although it is possible through the present invention to produce particulates less than 1 micron in diameter, these particulates are considered desirable for fuel injection. The particulates of any given aerosol all have approximately equal diameters, and the relative standard deviation is
10% to 30%, more preferably 3% to 20%. The fact that the aerosol particles have a particle diameter in the range of 10 or 100 microns means that another particle has a different diameter, one having a diameter of 10 microns and another having a diameter of 100 microns. It does not mean having. All (preferably 90% or more) microparticles in a given aerosol have the same diameter in the range of ± 3% to ± 30%. For example, the particles of a given aerosol have a diameter from 25 microns ± 3% to 25 microns ± 10%. Such monodisperse aerosols are produced using the components and compositions described above. However, those skilled in the art will be able to devise other components and configurations. The purpose of each design is to provide a formulation, thereby producing a stable capillary microjet that is accelerated and stabilized by tangential viscous stresses acting on the liquid surface from the gas. The stable capillary microjet created by the gas leaves the pressure gas area (eg, leaves the pressure chamber and exits the orifice of the pressure chamber) and breaks up into particulates of the desired size and uniformity. The aerosol produced is a monodisperse aerosol, which means that the microparticles produced are relatively uniform in size. The relative standard deviation in particle size ranges from about 10% to about 30%, preferably from 3% to 10%, and most preferably 3% or less. The size of aerosolized particulates useful for combustion ranges from about 10 nm to about 10 microns in diameter. For simplicity, in the following detailed description of the operation of the device shown in FIG. 1, the first fluid is a liquid and the second fluid is a gas. The parameter window used (ie, a specific set of values for the liquid properties, flow rate used, diameter of the feeding needle, diameter of the orifice, pressure ratio, etc.) is compatible with virtually any liquid Large enough to ensure the properties (dynamic viscosity range 10 ^{-4 to 1} kgm ^-1 s ^-1 ) so that the capillary microjets appearing at the end of the feeding needle are absolutely So that the perturbations caused by the collapse of the jet cannot move upstream. Downstream, the microjet is similar to a laminar capillary jet falling from a slightly open faucet,
Capillary instability (see, for example, Rayleigh's "On the instability of jets" at London Math. Soc., 1878, pages 4-13. ) Only breaks into equally formed drops. Once a stationary, stable interface has been formed, the capillary jet emerging at the end of the drop at the outlet of the feeding point is drawn into the nozzle, coaxially with it. After the jet emerges from the drop, the liquid is accelerated by the tangential sweep force created by the action of the gas stream flowing over its surface, which gradually reduces the cross-sectional area of the jet. In other words, as it moves toward and into the exit orifice of the pressure chamber, the gas flow acts as a lens, focusing and stabilizing the microjet. The force acting on the first fluid (eg, liquid) surface by the flow of the second fluid (eg, gas) must have sufficient stability to prevent irregular surface vibrations. In other words, the turbulence of the gas motion is avoided, and even at high gas velocities, the laminar nature of the gas motion (similar to the boundary layer formed on the inner surface of the jet and the nozzle or hole) due to the characteristic size of the orifice ) Needs to be guaranteed.

[0008] Stable Capillary Microjets [0008] FIG. 4 illustrates the interaction of a liquid and a gas to form an atomized product using the method of the present invention. Feeding needle 60, the inner radius has a circular outlet opening 61 to R _1, eject out the liquid 62 from its end, was added the thickness of the needle from R ₁ to R ₁ value To form a drip having a radius in the range up to afterwards,
The dripping circumference is narrowed as shown in the enlarged view of the tube (that is, the feeding needle) 5 shown in FIGS. 1 and 4, and the circumference is further reduced. The drained liquid flow consists of an infinite stream of liquid stream 63 that forms a stable peak at the interface 64 of the two fluids after the interaction of the liquid and the surrounding gas. The surrounding gas also forms an infinite streamlined gas stream 65, which interacts with the solid surface and the discharged liquid to form a virtual converging funnel 66. Discharged liquid is converged by this converging funnel 66 so that a stable capillary microjet 67 is created, the stability of which is maintained until it exits the opening 68 of the pressure chamber 69. After exiting the pressure chamber, the microjets begin to split, forming monodisperse particulates 70. The gas flow affecting the outflow of liquid and the subsequent acceleration after jet formation is:
It needs to be very fast, but at the same time it needs to be uniform to avoid perturbation of the fragile capillary interface (the dripping surface emerging from the jet). As shown in FIG. 4, the outlet opening 61 of the capillary tube 60 is disposed near the outlet opening 68 in the plane of the pressure chamber 69. This outlet opening 68 has a minimum diameter D ₀ and has a thickness
e is provided on the flat member. The diameter D ₀ is called the minimum diameter because the opening has a conical configuration and the conical small diameter end is located closer to the source of the liquid flow. That is, the outlet opening is a funnel-shaped nozzle, but other opening configurations such as a leak-shaped configuration are also possible. The gas in the pressure chamber flows out continuously through this outlet opening. This flow of gas causes a dripping of the liquid out of the tube, reducing its circumference as it moves away from the end of the tube and towards the outlet opening of the pressure chamber. In practical use, the shape of the opening that causes the maximum gas acceleration (and consequently the most stable peaks and microjets for a given set of parameters) becomes a conical opening in the pressure chamber. I can understand. The conical opening is arranged with its narrow end facing the source of the liquid flow. The distance between the end 61 of the tube 60 and the starting position of the outlet opening 68 is H. Here, it should be noted that preferably R ₁ , D ₀ , H and e are all on the order of 100 microns. For example, R ₁ = 400 m, D ₀ = 150 m, H = 1 mm, and e = 300 m. However, each can take values from 1/100 to 10 times these sizes. The end of the liquid stream exits the pressure chamber 69 when the applied pressure drop P _g that occurs through the outlet opening 68 becomes dominant over the liquid-gas surface tension stress / R * that appears at the point of maximum curvature. Critical distance from opening 68, for example 1 / R * from exit opening
At a distance of. Thereafter, a steady state is established if the flow rate Q of the liquid discharged from the dripping point is constantly supplied from the capillary. This is the stable capillary tip, a fundamental feature of the present invention, which is required to form a stable microjet. More particularly, stable thin liquid jet having a diameter of representative value d _j is, is smoothly discharged from a stable nose shape, the thin liquid jet extends over a range from microns stand to millimeters stand. The length of a stable microjet can vary from very short (eg, 1 micron) to very long (eg, 50 mm), with (1) liquid flow rate, and (2) ) Depends on the Reynolds number of the gas stream flowing outside the outlet opening of the pressure chamber. Liquid jets are stable capillary microjets that are obtained when a supercritical flow is reached. This jet has stable behavior provided that the pressure drop P _g applied to the gas is sufficiently large (on the order of / d _j ) compared to the maximum surface tension stress acting on the liquid-gas interface. show. The jet has a slightly parabolic axial velocity profile, many of which contribute to the stability of the microjet. This stable microjet is formed without the need for other forces, that is, without the need for additional forces such as electrical forces acting on the charged body. However, in some applications, it may be preferable to charge the microparticles, for example, to attach the microparticles to a predetermined surface. The shape of the liquid exiting the capillary by the gas flow forming the converging funnel forms a pointed meniscus, which results in a stable microjet. This is a feature underlying the present invention. A stable capillary microjet is kept stable over a considerable length from the tube in the direction away from the outlet. The liquid becomes a "supercritical flow" at this point. Eventually, the microjet becomes unstable due to the effect of surface tension. The instability resulting from the micronature perturbations traveling downstream, together with the fastest growing perturbations dominating microjet splitting, ultimately creates the monodisperse aerosol 70 of uniform size shown in FIG. This microjet exits through the outlet orifice of the pressure chamber without touching the peripheral surface of the outlet opening, even if it may be initially destabilized.
This provides an important advantage of the present invention in that the outlet opening 68 (also referred to as a nozzle) is not clogged by liquid residues and / or precipitation. Clogging is a major problem for very small nozzles and is generally addressed by cleaning or replacing nozzles. When there is contact between the fluid and the nozzle opening surface, when the flow of the fluid is shut off, some fluid remains in contact with the nozzle. The liquid remaining on the nozzle surface evaporates to produce a residue. After many uses, residues accumulate and clog. The present invention substantially reduces or solves this clogging problem.

(Mathematics of Stable Microjet) Using a cylindrical coordinate system (r, z), a shape analysis of a stable microjet, ie, a liquid jet subjected to “supercritical flow” is performed. Tube
The pointed meniscus formed by the exiting liquid is the pressure gradient created by the gas flow.
Arrangement pulls it towards the outlet of the pressure chamber. The pointed meniscus formed at the mouth of the tube is the pressure gradient created by the gas stream.
Depending on the arrangement, it is pulled towards the hall. From the tip of this meniscus, P_gTo
Suction effect and tangent acting axially from gas to jet surface
Direction viscous stress_sBy both actions, a stable liquid thread with a shape of radius r =
Pulled through the hall. The equation for average momentum for this configuration is
Can be expressed as d {P_l + (₁Q^Two) / (2^{Two Four})} / d_z = 2_s / (1) where Q is the flow rate of the liquid as it exits the feeding tube, P_lIs the pressure of the liquid,₁Is the density of the liquid, and the viscosity term is assumed to be negligible as compared to the kinetic energy term, as we will see later. In addition
Therefore, the effect of liquid evaporation is neglected. Liquid pressure P_lIs given by the following capillary equation:
Is given. P_l = P_g + / (2) In this case, it is the surface tension of liquid-gas. Pressure drop P as shown in the example_g Is sufficiently large compared to the surface tension stress /, which provides the rationale that the latter can be ignored in the analysis. This scenario assumes that the microjet is absolutely stable.
Is maintained over the entire range of flow rates. In fact, for a given pressure drop P_gNitsu
Minimum fluid flow rate that can be sprayed under stable jet conditions.
Since the surface tension acts like the “resistance” of motion (appears as a negative term on the right side of Equation (1)), the stress / of the surface tension becomes the kinetic energy (₁Q^Two) / (2^{Two Four})
Achieved when the degree. That is, Q_min = {(d_j ^Three) /₁)}^1/2 (3) Q_minIf the flow rate Q is sufficiently large compared to, the equation for the average momentum in the axial direction is expressed as follows. d {(₁Q^Two) / (2^{Two Four})} / d_z = dP_g / d_z + 2_s / (4) In this, it can be seen that the two driving forces for the fluid flow are located on the right side. This equation can be integrated by assuming the following simplification:
Can be. That is, the thickness L of the same value as or smaller than the diameter D of the hole
Thin planes (this minimizes downstream perturbations in the gas flow)
And the pressure gradient to the outlet of the hole is, on average, the surface stress
Viscous shear term 2_s/ Is much bigger. On the other hand, the viscosity term in the axial direction is expressed as O {(since the hole diameter D is actually a characteristic distance associated with the gas flow at the entrance of the hole in both the radial and axial directions.^TwoQ / D^Twod_j ^Two )become. This term is_g>>^Two/ D^Two ₁(This is, for example, D ≒ 10m and P_z≧ 100mbar
When using hole diameters and pressure drops as small as 1 mm, it is applicable for liquids with viscosities as high as 100 centipoise).
It is very small compared to the pressure gradient. From the above, the argument was obtained that all viscous terms in equation (4) can be ignored. Where this restriction on fluid flow
Is quasi-equal on average in contrast to most micron-class spreading flows.
It becomes a tropic flow (the liquid almost follows Bernoulli's equation). So both
By integrating equation (4) from the fluid stagnation region to the outlet, the following simple and universal equation for the jet diameter at the hole outlet can be obtained. d_j = {(8₁ / (^TwoP_g))^1/4 Q^1/2 (5) This is the pressure drop P_gAre the geometric parameters (hole and tube
Diameter, distance between tube and hole), viscosity of liquid and gas, and liquid
This shows that the gas is independent with respect to the surface tension. This diameter is the gas pressure
It remains constant after the exit, so it remains almost constant up to the split point.
Be held.

Having described stable microjets undergoing “supercritical flow”, this aspect of the invention has been clogged by various industrial applications, especially fluids passing through microholes. It shows how it can be used in problem areas. Aspects of the invention of equal importance are obtained after the microjet has left the pressure chamber. When the microjet leaves the pressure chamber maintains the pressure P _l of the liquid (like the pressure P _g of the gas) almost becomes constant in the axial direction, the diameter of the jet to the point of dividing the instability of the capillary, substantially constant Is done. Weber number, We = ( _{g g} ² d _j )
Defining / = 2P _g d _j / (where _g is the velocity of the gas measured at the orifice), the break-up mode is axisymmetric below a certain experimental value We _c ≒ 40, and consequently The resulting microdrop stream is simple if the fluctuations in gas flow do not contribute to the aggregation of the microdrops (these fluctuations occur when the perturbation profile of the gas stream appears completely around the breakup region of the fluid jet). Characterized as being variance. Beyond this We _c value, wavy non-axisymmetric disturbances linked to axisymmetric擾turbulent becomes remarkable. For large We numbers, the nonlinear growth rate of the wavy disturbance tends to overwhelm that of the axisymmetric disturbance. In this case, the resulting spray shows significant polydispersity. From this, it can be seen that by controlling the parameters and keeping the resulting Weber number to 40 or less, the microparticles formed have substantially the same size. This size variation is about ± 3% to ± 30%, more preferably ± 3% to ± 10%.
These microparticles can have any desired size, for example, from 0.1 microns to 50 microns. Shed speed affects jet break-up, and thus affects particulate formation. In the acceleration region upstream from the hole exit, the gas stream becomes laminar. A typical value of the Reynolds number is in a range from 500 to 6000 if a speed equivalent to the speed of sound is considered as a characteristic speed of gas. Downstream of the hole exit, the cylindrical mixing layer between the gas stream and the stagnant gas is destabilized by classical Kelvin-Helmholtz instability. The growth rate of this layer thickness depends on the Reynolds number of the flow, and when D is the hole diameter, a vortex ring is formed at a frequency near _g / D. Typical _g and D values found in our experimental technique have led to frequencies on the order of MHz, which are comparable to the frequency of drop generation (t _b ^-1 ). Given the flow rate of the liquid and the hole diameter, it depends on the gas velocity (or pressure difference driving the gas stream) in such a way that the vortex acts as a facilitating system to excite a determined wavelength perturbation of the jet surface. The resonance frequency can be adjusted (tuned). The experimental results obtained showed distinctly different degrees of coupling between the two gas-liquid concentric jets. One set of experimental results revealed a particle size of about 5.7 microns, with a standard deviation of 1
2%. This result was obtained by properly adjusting the gas velocity to minimize variations in the size of the microdroplets resulting from jet break-up. The liquid jet flow rate and its diameter in this case are 0.08
l · s ^-1 and 3m. Data was collected using a MALVERN INSTRUMENTS MASTERSIZER. As the coupling decreases, perturbations of the jet surface at different wavelengths are excited, increasing the variability of the spray, as seen in the size distribution. For many different industrial applications, it is highly desirable to obtain particulates that are uniform in size, or to produce aerosols of liquid particulates that are uniform in size. For example, particles of a liquid formulation containing hydrocarbons are produced and 10 μm ± 3
Designed to have a% diameter. These particles are injected into the combustion chamber of the engine. Further, the particle size is tuned to increase fuel efficiency, reducing fuel waste in the combustion reaction. Upstream of the orifice outlet, the turbulent regime, i.e. the gas flow needs to be laminar to avoid turbulent fluctuations in the gas flow that has a high frequency and perturbs the liquid-gas interface , Orifice reached at the orifice is given by: Re = ( _g d ₀ ) / _g ≒ 4000 where _g is the velocity of the gas. Despite this number being very large, a large pressure gradient (high convergence zone) exists downstream, which makes it very unlikely that a turbulent regime will occur. The fundamental difference between the present invention and the conventional pneumatic atomizer (having a large Weber number) is that the aim of the present invention is not to break the liquid-gas interface, but vice versa, ie, until the capillary jet is obtained. The purpose is to increase the stability. Jet
If the pressure drop resulting from the spill is sufficiently high, it will be very thin, resulting in a drop of much more uniform size than the drop resulting from the disordered breaking of the liquid-gas interface in a conventional pneumatic atomizer. Split. The proposed fuel injection nozzle system explicitly requires the fuel to be aerosolized and the gas used to generate the spray. Both need to be supplied at a rate that maintains the system within a stable parameter window. Multiplexing is effective when the required flow rate exceeds that of the individual cells. More specifically, the use of multiple feeding sources or needles can increase the rate at which aerosols are generated. Flow used
The rate must ensure that the mass ratio between the flows is consistent with the specifications for each application. Gases and liquids are dispensed by any continuous supply system (eg, a compressor or a pressurized valve system). If multiplexing is required, the flow rate of liquid between cells should be as uniform as possible, including propulsion through multiple capillary needles, uniformity between different feeding points. A porous or other medium capable of distributing the flow is required. Each individual jet nozzle has at least one feeding point (capillary needle, point with an open microchannel) of 0.002 to 2 mm (preferably 0.01 to 1.2 mm) in diameter that allows anchoring of the dripping emerging from the microjet. Small orifices with diameters of 0.002 to 2 mm (preferably 0.01 to 1.0 mm) facing the drop and 0.01 to 2 mm (preferably 0.2 to 0.75 mm) away from the feeding point. Will be composed of The orifice transfers the effluent gas at or near the higher pressure to a lower pressure zone where the atomized product occurs. The injection valve can be made using various materials (preferably, materials that do not react with fuel, metals, polymers, and the like). Figure 1 shows the prototype tested, in which the liquid to be atomized is inserted at one end 2 of the system and the gas is supplied to a special inlet 4
Through the pressure chamber 3. The prototype, a pressure above atmospheric pressure P _a discharged liquid that is atomized is tested in the gas supply rate of up to 2000 mbar Lumpur from 100 mbar. The pressure of the entire enclosure surrounding the feeding needle 1 was the P _0> P _a. The liquid supply pressure _Pl must always be slightly higher than the gas propulsion pressure _Po . Depending on the pressure drop in the needle and the liquid supply system, the pressure difference (P _l -P ₀ > 0) and the liquid flow rate Q of the atomizing fluid will be linear as long as the flow is laminar and this In the case of the prototype, there is no missing example. The critical dimensions are the distance from the needle to the plate (H), the diameter of the needle (D ₀ ), the diameter of the orifice from which the microjet 6 is discharged (d ₀ ), and the axial length e of the orifice (ie, the orifice is Thickness of the plate made). In this prototype, the distance (D ₀ = 0.45 mm,
H was varied from 0.3 to 0.7 mm while d ₀ -0.2 mm) and e-0.5 mm were kept constant. The quality of the resulting spray 7 did not change appreciably with changes in H as long as the operating regime (ie, steady drop and microjet) was maintained. However, the system had an effect on stability when the distance H was longer (about 0.7 mm). Other atomizer dimensions did not affect spray or prototype function as long as the zone around the needle (its diameter) was sufficiently large relative to the feeding needle.

(Weber Number) The parameter adjustments to ensure a stable capillary microjet and control its breakup into monodisperse microparticles are based on the Weber number and the liquid to gas velocity ratio, ie V _l / V _g Is governed by represented by The Weber number, or “We”, is defined using the following equation: We = ( _g V _g ² d) / where _g is the density of the gas, d is the diameter of the stable microjet, is the liquid-gas surface tension, and V _g ² is the square of the gas velocity. When practicing the present invention, to produce a stable capillary microjet,
It must be adjusted so that the Weber number is greater than one. However, in order to make the dispersion of the particles monodisperse (ie, each particle has the same size in the range of ± 3% to ± 30%), adjust the parameters so that the number of Webers is less than about 40. There is a need. Monodisperse aerosols are obtained when the Weber number ranges from about 1 to about 40 (1 ≦ We ≦ 40).

[0012] The relative importance of viscosity in jet break-up is determined by two characteristic times, viscous time t_vAnd break time t_bOhnesaw defined as the ratio between
It can be evaluated from the number of dice. Break time t_bIs given by the following equation (
Rayleigh (1878)). t_b = {(_ld^Two) /}^1/2 (2) The perturbation of the jet surface is determined by viscous diffusion,_vPropagated by t_v≒ (_ld^Two) /₁ (3) In this,₁Is the viscosity of the liquid. Accordingly, the Ohnesage number Oh can be expressed using the following equation. Oh =₁ / (_ld)^1/2 (4) If this ratio is sufficiently smaller than 1, viscosity has no essential role in the phenomenon under consideration. The maximum value of the number of annesage in the actual experiment was 3.7 × 10^-2Moderately low during the jet break-up process
Has no intrinsic effect of viscosity. The formation of the microjet and its acceleration, and the formation of the final particles,
When passing through the outlet orifice of the pressure chamber holding the second fluid, the first
It is based on a sharp decompression associated with a steep acceleration experienced by a fluid (eg, a gas). this
When the fluids exit the chamber, a first fluid (eg, a liquid) and a second fluid (eg,
(Eg, gas), which in turn creates a sharply bent zone on the surface near the outlet port of the pressure chamber of the first fluid (eg, liquid) to create cusps.
As a result, a stable microjet is obtained as long as the amount of the first fluid (eg, liquid) flowing out through the outlet port of the pressure chamber is replenished. One
In other words, when a glass lens or eyeball lens focuses light at a given point
In the same manner as above, the gas flow envelops the liquid and forms a stable microjet.
Let it converge. The effect of convergence due to this surrounding gas flow is substantially straightforward.
Produces a stream of liquid whose diameter is smaller than the diameter of the pressure chamber exit orifice
You. This allows the liquid to come into contact with the orifice from the pressure chamber orifice
It becomes possible to flow without doing. This results in (1) virtually eliminating clogging of the exit orifice, (2) substantially eliminating contamination due to contact with objects on the orifice opening, (3) stream and results. The diameter of the resulting fine particles is smaller than the diameter of the outlet orifice of the chamber, and (4) the fine particles after exiting the chamber have a higher gas velocity than the liquid gas.
The advantage of accelerating the ream offers the advantage of not having a tendency to form clots
. This is especially desirable due to the difficulty in accurately machining very small diameter holes.
Good. Moreover, in the absence of this convergence effect, the flow of fluid exiting the aperture is
About twice the diameter of the outlet opening. In summary, results in liquid efflux and subsequent acceleration after jet formation
The flow of fluid 2 needs to be very fast, but at the same time equalized to avoid perturbation of the fragile capillary interface (the drip interface emerging from the jet) and thus its destruction.
Need to be one. That is, the dynamic forces acting from the fluid 2 must not always exceed the surface tension (drops and microjets) during the process. Fluid force
From a dimensionless dimension of science, the Weber number (ie force versus surface tension)
Ratio) should not exceed 1. The Weber number of the microjet is necessarily equal to 1 since the pressure drop of fluid 2 equals the effect of surface tension in magnitude: 2 / d_j≒ (_g ^Two) / 2 where and are surface tension and liquid concentration, respectively; d_jand_g Is the characteristic diameter of the jet and the characteristic velocity of the fluid 2. Also, the velocity of the fluid 2 around or around the jet producing correlate with that across the area before and after the orifice, i.e., V_gDrop the velocity of fluid 2 around the₀And d₀Where V is the diameter of the feeding point and orifice, respectively._gD₀ ^Two≒_gd₀ ^Two It is necessary to The maximum possible velocity of fluid 2 at the orifice is similar to the speed of sound
V_g≒ (d₀ / D₀)^Two× 320 m / s, and the following equation regarding the jet diameter is obtained. d_j≒ (4) / (p_{g g} ²⁾≒ 4 × 2 × 10^Two / (1.2 × 320²⁾≒ 5 m (In the case of n-heptane, = 2 × 10^Two N / m^TwoThis is for diameters from 1 to 10 microns and even smaller than 1 micron.
This means that micron-order drops having a size can be obtained. At the smallest diameter possible with this system (as well as the thickness of the boundary layer)
The kinetic energy per unit volume of the liquid and the fluid 2 needs to be the same. The resulting velocity of the liquid is: V_l≒ (_g /_l)^1/2 _g≒ 10 m / s where_lIs the concentration of the liquid. From the above equation, the liquid flow rate is Q at the smallest drop size_l≒ d_j ^Two _l≒ 10^-11 m^Three/ Sec. The flow of fluid 2 has a turbulent regime, i.e., a high frequency,
The gas flow needs to be laminar in order to avoid turbulence fluctuations in the flow of the fluid 2 that causes perturbation at the interface. The Reynolds number reached at the orifice is
Given by the equation. Re = (_gd₀) /_g≒ 4000 in this_gIs the velocity of fluid 2. Although this number is very large,
Large pressure gradient (high convergence zone) downstream creates turbulence regime
Very unlikely to be. The basic difference from a conventional pneumatic atomizer (with a large number of Webers) is that
The aim is not to break the liquid-fluid 2 interface, but vice versa, to increase the stability of the interface until a capillary jet is obtained. Jets spill
If the pressure drop resulting from the result is sufficiently high,
It breaks up into drops of much more uniform size than the drops resulting from the disordered breaking of the liquid-fluid 2 interface in a formula atomizer.

(Example of Use of First Embodiment) The first embodiment of the present invention is used for a nozzle type injection device for injecting finer and more uniformly dispersed liquid fine particles into a combustion chamber, for example. can do. It is desirable to have multiple injection points for each device since each injection involves the ejection of a relatively small amount of liquid due to the nature of the fine particles formed. The device will therefore have multiple feeding needles in a single injection device, preferably with 10, more preferably at least 100, even more preferably at least 500, even more preferably at least 10
00. The injection points can be spatially located within the device in any manner that can efficiently generate particulates, but preferably reduce the tendency of the particulates to form agglomerates after entering the combustion chamber In such a configuration, the injection points are arranged, for example, in the device in parallel at equal intervals. Gases and liquids used for fuel
For example, it can be distributed to the feeding needles by any type of continuous supply system, such as a compressor or pressure tank for gas supply and a volume pump or pressure bottle for liquid supply. Gas and / or liquid variability can be controlled using any mechanism known in the art,
For example, the use of valves to control gas and / or liquid entering the inlet tube leading to the injection device. The device housing and the feeding needle can be made of various materials (metals, plastics, ceramics, glass), but are preferably made of materials that do not react with the fluid in the device. FIG. 6 schematically shows an example in which the embodiment shown in FIG. 1 is used in an injection device. In the device shown in FIG. 6, a plurality of equally spaced feeding needles 84 are housed in a pressure chamber 80, and fuel is atomized from a plurality of outlet openings 81 of the pressure chamber 80. FIG. 6A is a side view showing the interior of the device with multiple injection needles 84 housed inside a single pressure chamber 80. FIG. The pressure chamber shall provide approximately equal pressure throughout the chamber such that a stable peak convergence can be efficiently generated for each individual feeding needle. Alternatively, each feeding needle may independently have a pressure chamber, each controlled individually, having approximately equal pressures, and partitioned into chambers into which fluid flows equally. Fuel is supplied to the feeding needle via an inlet opening 82, and the flow of fuel is preferably controlled by a mechanism within the fuel injector, such as a valve whose opening and closing is controlled using computer signals to the fuel injector. Is done. Again, incorporated by reference, see U.S. Patent Nos. 4,984,552 and 5,697,341. In the example shown in FIG. 6, fuel is supplied from a single source to each individual needle via a fuel supply tube 83 that is above and connected to a feeding needle 84. You. Alternative ways of directing fuel to individual feeding needles can use individual fuel supply tubes extending from a single fuel source or from multiple fuel sources. If multiple sources are used, they are preferably synchronized and / or adjusted to control the amount of fuel injected. The second fluid used to converge the first fluid is provided via at least one independent inlet 86. FIG. 6B is a bottom view of the device, showing a plurality of outlet openings 81 in the pressure chamber 80. FIG. Although only a single pressure chamber is shown in FIG. 6, multiple pressure chambers may be provided to increase the efficiency of the device. Individual chambers can be supplied with fluid from a single outlet source or from multiple sources. In another use of the embodiment shown in FIG. 1, fuel is provided as the second fluid of the present invention, and gas, preferably air, is used as the first fluid. This gas is supplied via a feeding needle and a fuel formulation is introduced into the pressure chamber. This fuel is used to focus the gas, which is released in the form of particulates.
As the second fluid, the fuel coats the gaseous particulates as it exits the pressure chamber. By discharging the gas bubbles contained in the liquid stream into the gaseous environment, highly dispersible fuel globules with a gas, preferably air, are obtained.
This use of injection nozzles increases the surface area of the fuel mix available for the reaction, while
Fuel components can be maintained.

Embodiment of FIG. 2 One of ordinary skill in the art, upon reading this disclosure, will appreciate the various component configurations as well as fluid types. These configurations and fluids are included in the present invention as long as they can produce a stable capillary microjet of the first fluid from the source toward the outlet port of the pressure chamber containing the second fluid. The stable microjet flows from the feeding source towards the outlet port of the pressure chamber, and from the second fluid in the pressure chamber, by tangential viscous stress acting on the first fluid surface forming the microjet. Accelerated and stabilized. The second fluid forms a converging funnel when the various parameters are properly tuned or adjusted. For example, the velocity, pressure, viscosity and miscibility of the first fluid and the second fluid converge toward the center of the funnel formed by the second fluid, with the desired result of the first fluid. Selected to obtain a stable microjet. These results can be used to adjust or tune the physical parameters of the device, including the size of the opening through which the first fluid exits, the size of the opening through which both fluids are ejected, and the distance between the two openings. It is also obtained by doing. The embodiment shown in FIG. 1 can itself be arranged in various configurations. Furthermore, as mentioned earlier, it is also conceivable that this embodiment comprises a plurality of feeding needles. A plurality of feeding needles can be concentrically configured into a single structure, as shown in FIG. The components of the embodiment shown in FIG. 2 are as follows. 21. Feeding needle-a source or tube of fluid. 22. End of the feeding needle used to insert the liquid to be atomized. 23. Pressure chamber. 24. Orifices used as gas inlets. 25. The end of the feeding needle used to drain the liquid to be atomized. 26. The orifice where the spill occurs. 27. Atomizing product (spray) or aerosol. 28. The first fluid to be atomized (the nucleus inside the particles). 29. Second fluid to be atomized (particulate outer coating). 30. Gas for generating microjets. 31. Inner tube of the feeding needle. 32. Outer tube of the feeding needle. D = diameter of the feeding needle; d = diameter of the orifice through which the microjet passes; e = axial length of the orifice where the outflow occurs; H = feeding diameter.
Distance from the needle to the outlet of the microjet; = surface tension; P ₀ = pressure in the chamber; P _a = atmospheric pressure. The embodiment shown in FIG. 2 is preferably used when attempting to form spherical microparticles of a substance coated with another substance. The device shown in FIG. 2 consists of the same basic components as the device shown in FIG. 1 and a second feeding source arranged concentrically around a first cylindrical feeding source 31.・ Source 3
2 is provided. This second feeding source may be wrapped by one or more additional feeding sources, each concentric with the inner source. The process involves subjecting a liquid-gas or liquid-liquid (if immiscible) interface phase to the point at which one fluid begins to aspirate while the combined aspiration of the two fluids occurs. Based on micro suction. This interaction physically encloses the fluid by the other, forming a capillary microjet that eventually breaks into a spherical drop. Instead of two fluids (gas-liquid), if three or more fluids that flow concentrically by injection using concentric tubes,
A capillary jet consisting of or more layers of different fluids is formed and, when split, forms a sphere consisting of a generally concentric spherical layer of different fluids. The size of the outer sphere (its thickness) and the size of the inner sphere (its volume)
Is precisely adjustable. This method is based on the splitting of a capillary microjet consisting of one liquid or gas nucleus and another (one or more) liquid or gas enveloping it, each of which is stable. Are ejected concentrically by a special ejection head in such a way that they form a capillary jet and do not mix with each other by diffusion between the time the microjet is formed and the time it splits. When the capillary microjet breaks up into spherical drops under proper operating conditions, as will be described in detail below, these drops exhibit a spherical nucleus whose size and eccentricity can be controlled. In the case of a sphere containing two raw materials, the ejection head 25 consists of two concentric tubes having an outer diameter on the order of 1 millimeter. A raw material that constitutes the core of the microsphere is sprayed through the inner tube 31, and a coating is sprayed from between the inner tube 31 and the outer tube 32. The fluid in the outer tube 32 is
Upon exiting the needle, it combines with the fluid in the tube 31 so that these ejected fluids (usually liquids) are accelerated by the gas stream through the micro orifice 24 directly opposite the end of the ejection tube. If the pressure drop through the orifice 24 is sufficient, the liquid forms a completely stationary capillary jet unless the amount of liquid to be ejected changes. This microjet passes through the funnel formed by the gas from the gas stream or tube 32 without contacting the orifice walls. Because the gas funnel focuses the liquid, the size of the particulate formed is not governed by the exit orifice size 26. If the parameters are properly adjusted, the movement of the liquid at the outlet orifice 26 is uniform and the viscous forces are small enough that it changes the flow or liquid properties, for example, certain complexity and weakness If there are sexual biochemical specimens, the viscous forces that appear in connection with the flow through the micro-orifices can degrade these substances, but they do not. FIG. 2 is a simplified diagram of a feeding needle 21 that includes a concentric tube 30 that provides an inner flow and an outer flow of fluids 28, 29 that will constitute a microsphere consisting of two immiscible fluids. , 31 are provided. Orifice 26 pressure difference P ₀ −P _a (
P ₀ > P _a ) causes a flow of gas introduced into the chamber 23, which wraps around the microjet at the outlet. Pressure difference P ₀ -P _a is, if sufficiently large in comparison to the surface tension that creates a gradient that acts on the moving direction and opposite, the same pressure gradient to move the gas microjet through a hole 26 in the axial direction To move. Regarding the minimum size of the inner and outer jets, (a) the outer liquid 2
9 and surface tension 1 and tension second outer liquid 29 and the liquid inside 28 of the gas 30, and (b) 2 one restriction which depends respectively on the pressure difference P = P ₀ -P _a through orifice 26 There is. First, the jump P in pressure must be large enough to minimize the harmful effects of surface tension. However, this is achieved by a very modest increase in pressure, for example, for a 10 micron jet of liquid (tap water) having a surface tension of 0.05 N / m, the required minimum jump in pressure is 0.05 (N / m ) /0.00001 m = P = 50 mbar. However, in order for the drop to have a uniform size, the splitting of the microjet must also be regular and axisymmetric, so that the surface tension of the outer fluid and gas1 and the outer diameter of the microjet P cannot be increased excessively beyond a predetermined value depending on both. Experimentally, it has been shown that this pressure difference cannot be increased beyond the value obtained by multiplying the surface tension by 20 and dividing by the outer radius of the microjet. Thus, given the inside and outside diameter of the microjet,
An operating pressure range between the minimum and maximum will be determined, but experimentally, optimum results have been obtained at pressures of about two or three times that minimum. The value of the viscosity of the liquid must be such that the liquid with a higher viscosity _max demonstrates the following inequality for the expected jet diameter d and the difference P through the orifice for this liquid. _max ≦ (Pd ² D) / Q whereby the pressure gradient can overcome the viscous drag pull that it brings when the liquid is drawn towards the orifice. Furthermore, to achieve concentricity of the microsphere nuclei, the velocity relationship between each liquid varies according to the square root of density v1 / v2 = (2/1) ^1/2 , and both jets, In other words, it must be assumed that the inner and outer jets have the most symmetrical configuration possible, which is not possible if the liquids have different velocities. 2) Each liquid must have very similar densities. Nevertheless, it has been experimentally demonstrated that within the defined parameters, the interfacial tension 2 between the two liquids tends to cause the nucleus to move towards the center of the microsphere. If two liquids and a gas outside are used, unless the inner tube 31 is plugged into the outer tube 32 beyond the diameter of the outer tube 32, and the inner tube 31 is more than twice its diameter As long as it does not protrude beyond the outer tube 32, the distance between the planes containing the openings of the concentric tubes can be changed without substantially changing the properties of the jet. For best results, replace inner tube 31 with outer tube
It is obtained when projecting from 32 by a distance substantially equal to the diameter of the inner tube 31. When more than two tubes are used, the same criteria are valid, including the included tube (the inner tube) and the included tube (the inner tube).
Over the outer tube) by a distance substantially equal to the diameter of the former tube. The distance between the plane of the inner tube 31 (which will normally protrude) and the plane of the orifice depends on the surface tension between the liquid and the gas and their viscosity values,
The value can range from zero to three times the outer diameter of the outer tube 32. The optimal distance is usually determined experimentally for each individual configuration as well as for the set of liquids used. Each atomizing device has a range of 0.05 to 2 mm, preferably 0.1 to 0.4 m, each of which is capable of fixing a dripping microjet
concentric tubes 31, 32 having diameters in the range of up to m, and, confronting each other, in the range of from 0.001 to 2 mm from the feeding point, preferably 0.2 to 0
Consisting of micro orifices (having a diameter in the range of 0.001 to 2 mm, preferably in the range of 0.1 to 0.25 mm) separated by a distance in the range of up to .5 mm. These orifices entangle the drip gas at higher pressures and contact the aspirated gas at lower pressures with the area where atomization is achieved.

Example of Use of the Second Embodiment An embodiment of the second invention is very similar to the embodiment shown in FIG. 6, but can inject a plurality of compound particles into the combustion chamber. The points are different. This allows the surface of the fine particles to have a specific component of the overall composition of the fuel that is easily accessible to the surface, and the remaining components can be used as nuclei of the liquid fine particles. For example, a diesel fuel formulation includes kerosene, castor oil and isopropyl nitrate, with kerosene coated,
It is desirable that the remaining three molecules be the core of the fine particles. Thus, castor oil and isopropyl nitrate are each introduced into the inner tube of the feeding needle, and the preparation of kerosene (or kerosene dissolved in any of these) is directed to the outer tube of the feeding needle. This results in atomization of the kerosene-coated fuel particulates, increasing the surface area available for combustion reactions involving the kerosene component of the fuel composition. This embodiment can be used for any fuel composition where it is desirable to coat one or more components of the fuel composition with fuel particulates and place the remaining components inside the same particulates. A nozzle-type injection device using the second embodiment is very similar to FIG. 6, with multiple feeding needles located within a single pressure chamber or multiple pressure chambers. The main difference is that a separate source is used to introduce the fuel composition into the feeding needle for the particulate coating formulation and the particulate core formulation.

Embodiment of FIG. 3 The embodiment shown in FIGS. 1 and 2 is similar in many respects. Both have a feeding piece in the form of a feeding needle which preferably has a circular outlet opening. In addition, each has an outlet opening of the pressure chamber, which is arranged directly in front of the flow path of the fluid leaving the feeding source. Maintaining accurate alignment of the flow path of the feeding source and the outlet opening of the pressure chamber involves technical difficulties, especially when the device is equipped with multiple feeding needles. The embodiment shown in FIG. 3 is designed to simplify component alignment. The embodiment shown in FIG. 3 uses a planar feeding piece, in which multiple outlets through multiple outlet ports of the pressure chamber are used due to the outflow effect created by the pressure differential through the micro-aperture through which the fluid passes. Microjets can be released, resulting in multiple aerosol streams. Figure
Although FIG. 3 shows a single planar feeding member, it is of course possible to make a device with multiple planar feeding members, where each planar feeding member is The fluid is supplied to a linear array of outlet orifices provided in a pressure chamber surrounding the pressure chamber. In addition to that, the feeding member does not necessarily have to be strictly flat, but may be a two-sided, bent feeding device that maintains approximately the same spatial distance between the two feeding sources. Can be This type of bent device can have any level of curvature, such as a circle, semicircle, ellipse, semi-ellipse, and the like. The components of the embodiment shown in FIG. 3 are as follows. 41. Feeding piece 42. End of the feeding piece used to insert the liquid to be atomized. 43. Pressure chamber. 44. Orifices used as gas inlets. 45. The end of the feeding piece used to drain the liquid to be atomized. 46. The orifice where the spill occurs. 47. Atomizing product (spray) or aerosol. 48. First fluid containing the raw material to be atomized. 49. Second fluid for generating microjets. 50. The wall of the propulsion chamber directly opposite the end of the feeding piece. 51. Channel for guiding fluid through the feeding piece. d _j = diameter of the formed microjet; _A = liquid density of the first fluid (48); _B = liquid density of the second fluid (49); _A = velocity of the first fluid (48); _B = speed of the second fluid (49); e = axial length of the orifice extraction occurs; H = distance from the feeding needle to the outlet of the microjet; P ₀ = pressure in the chamber; p _g = changes in gas pressure; P _a = atmospheric pressure; Q = volumetric flow rate. The proposed particulate generation device consists of a feeding piece 41 that forms a planar feeding channel through which a first fluid 48 flows. This flow is preferably directed through one or more channels with a uniform bore formed on the plane of the feeding piece 41. The pressure chamber 43, which maintains the propulsion flow of the second fluid 49, houses this feeding piece 41 and places it under a maintained pressure above the outside of the chamber wall 50. One or more orifices, openings or slots (outlets) 46 formed in the wall 52 of the pressure chamber face the edge of the feeding piece. Preferably, each bore or channel of the feeding piece 41 has a flow path substantially aligned with the outlet 46. The formation and acceleration of the microjet is such that when the second fluid 49 is a gas, the second fluid 49 has an orifice similar to the process described above for the embodiment of FIGS.
It is based on the sudden pressure drop resulting from the sudden acceleration experienced when passing through 46. If the second fluid 49 is a gas and the first fluid 48 is a liquid, the microthreads formed are extremely long and the velocity of the liquid is much slower than the velocity of the gas. In fact,
Low gas velocities further reduce the velocity of the liquid flow, and consequently the micro-jets are actually created and accelerated by the stress, or pressure, normal to the liquid surface.
Thus, one valid approximation to this phenomenon is that the compressibility of a gas is negligible, and the resulting pressure differential results in the same kinetic energy per unit volume for both fluids (liquid and gas). It is assumed that An orifice that a pressure differential P _g back and forth, the diameter d _j microjet formed from liquid Density _l passing a volume flow rate Q is given by the following equation. d _j = {(8 _l ) / ( ² P _g )} ^1/4 Q ^1/2 Physical Review Letters by Ganan-Calvo 80: 285-288 (1998) Please refer to. The correlation between the microjet diameter d _j and the resulting drop diameter d (with an overscore) depends on the one hand on the ratio between the viscous force acting on the liquid and the surface tension, and on the other hand on the gas. It depends on the ratio between the working dynamic force and the surface tension (that is, the number of the horns and the number of the Webers, respectively) (Hinds (Aerosol
Technology, John & Sons (Aerosol Technology; John & Sons Publishing, 1982), Lefevre (Atomization and Sprays, Hemispher)
e Pub. Corp. (Atomization and Spray; Hemisphere Publishing Corporation, 1989) and Bayvel & Orzechowski (Liquid Atomization, Taylor & Francis (Liquid Atomization; Taylor & Francis) Publishing) 1993)). At moderate gas velocities and low viscosities, this relationship is roughly equivalent to that for capillary instability discovered by Rayleigh. d (with overscore) = 1.89d _{j Due} to the very long length of the liquid microjet, at high flow rates the theoretical break point is located in the turbulent zone created by the gas jet, and Turbulent fluctuations of the liquid microjet destabilize or break it into a somewhat non-uniform shape. As a result, the advantage of drop size uniformity is lost. In contrast, when the second fluid 49 is a liquid and the first fluid 48 is a gas, the fact that the viscosity of the liquid is much higher than the gas and the fact that the gas is much less sparse Thus, the micro-threads of the gas formed are much shorter, but the variation in the size of the micro-bubbles formed is almost always small, since their break zone is almost always located in the laminar stream. At the gas volume flow rate Q _g and the liquid overpressure P ₁ , the diameter of the gas microjet is given by: d _j = {(8 _g ) / ( ² P _l )} ^1/4 Q _g ^{1/2 where} _g is the density of the gas. When the velocity of the liquid is slow and there is no relative velocity between the liquid and the gas, a Rayleigh relationship (ie, d = 1.89d _j ) is derived between the microthread diameter and the bubble diameter. If both fluids 48, 49 are liquid and have little viscosity, their relative velocities can be determined from their density ratios as follows: v _A / v _B = a _(B / _A) ^1/2 volume flow rate and Q _A, when the overpressure and P _B, the diameter of the first microphone Rojetto liquid is given by the following equation. d _j = {(8 _A ) / ( ² P _B )} ^1/4 Q _A ^{1/2 In} viscosities where the velocities of both fluids 48, 49 quickly equilibrate in the microjet, the first liquid micro The diameter of the jet is given by: d _j = {(8 _B ) / ( ² P _B )} ^1/4 Q _A ^{1/2 The} proposed device obviously requires the supply of fluids 48, 49 at appropriate flow rates in the dispersion process. That is: (1) Both flow rates need to be adjusted for the system so that they fall within a stable parameter window. (2) The mass ratio between each flow must be consistent with the specifications for each application. Obviously, the use of external means can increase the gas flow rate even in special applications, since the use of external means does not hinder the operation of the atomizer. (3) Thus, liquids and gases can be supplied by any type of continuous supply system. (4) The pressure chamber housing and the feeding nozzle can be made of various materials, but are preferably made of a material that does not react with the organic solvent (eg, metal or plastic).

(Example of Use of Third Embodiment) FIG. 7 schematically shows an example in which the embodiment shown in FIG. 3 is used in an injection device. In this figure, a flat feeder is shown for use in a cylindrical spray configuration.
The element has been adapted. This device uses a single cylindrical feeding
Element or, more preferably, a plurality of concentric feeding elements, through which the fuel mixture for injection is guided. These feeding elements may be contained within a single pressure chamber (i.e., one or more feeding elements within a single pressure chamber), or each cylindrical feed may be contained within multiple pressure chambers. Preferably, one pressure chamber is provided for each feeding element. Alternatively, the feeding elements can be planar and the device can be constructed from a bank of planar elements to approximate the desired nozzle shape. FIG. 7A is a side view showing the inner portion of a single circular feeding element 93 housed within a single chamber 90. FIG. The feeding element is
Preferably within the element 92 there are a plurality of recessed chambers following the feeding outlet port 93. The outer surfaces of these outlet ports are designed so that the surrounding gas optionally points to the outlet opening of the pressure chamber 91, as shown in FIG. 7A. The chamber is aligned with the opening of the pressure chamber and provides better directional flow towards the outlet opening to assist in forming a converging funnel and stable microjet. FIG. 7B illustrates a plurality of apertures in a pressure chamber of a device having a plurality of concentric feeding elements and an equal number of pressure chambers 90.

(Fuel Injection Formulation) The composition used to produce the particulates in the present invention depends in part on the chemistry of the formulation to be atomized. For example, if the atomizing formulation is hydrophobic, such as a hydrocarbon, the solvent containing the formulation used in the process of the present invention will preferably be a solvent suitable for dissolving the hydrophobic compound, such as ether. . The hydrophobic component is preferably at least partially soluble in this solvent. The second fluid is preferably a gas, more preferably air, or a fluid immiscible with the first fluid. The fuel formulation used in the present invention can be of any composition that can be aerosolized or atomized for use in generating an internal combustion reaction. Formulations of this kind preferably comprise saturated aliphatic hydrocarbons obtained from petroleum, such as, for example, natural gas, kerosene, gasoline, diesel fuel and jet fuel. In addition to including a fuel composition base of molecules such as hydrocarbons, such formulations may also include additives that reduce fuel performance and / or harmful emissions, such as ethanol. Additional examples of fuel composition can be found in JA Kent, which is again incorporated by reference.
(Kent) Edited by Riegel's Handbook of Industrial Chemistry (1992). These formulations can be in the form of a solution dissolved in a solvent, a form suspended in a solvent, or an emulsion, slurry, etc. Any shape that can be atomized may be used.

Bubbles in Liquid or Gas FIGS. 8 and 9 are useful in showing embodiments in which bubbles are formed in a liquid (FIG. 8) or a gas (FIG. 9). In FIG. 8, a gas flow is continuously supplied to a hollow feeding source 71, which is a pressure chamber 74 to which a flow of a liquid 73 is continuously supplied.
Inside, a stable cusp 72 is formed that is enveloped by the flow of liquid 73.
The liquid 73 flows out of the chamber 74 into a liquid 75 which is the same as or different from the liquid 73. The gas peak 72 narrows into a capillary supercritical flow 76, which then enters the outlet opening 77 of the chamber 74. At point 78 of outlet opening 77, this supercritical flow 76 begins to become unstable, but maintains the shape of the critical capillary flow until it leaves outlet opening 77. Upon leaving the outlet opening 77, the gas stream splits and bubbles 79, each substantially equal in shape and size, to each other
To form The bubbles are uniform and preferably such that the difference in the amount of one bubble from another (at the measured physical diameter) falls within a standard deviation of ± 0.01% to ± 30%. Make it less than 1%. That is, the uniformity of the bubble size is higher than the uniformity of the fine particles formed at the time of forming the liquid fine particles described above in relation to FIG. The gas in the bubble 79 diffuses into the liquid 75. The smaller the bubble, the larger the surface area in contact with the liquid 75 can be obtained. Since the smaller the bubble, the larger the surface area in contact with the liquid 75 is obtained, a diffusion rate faster than the diffusion rate when the same volume of gas is present as a small number of bubbles is obtained. For example, ten bubbles, each containing 1 cubic millimeter of gas, diffuse into a liquid in much less time than one bubble containing 10 cubic millimeters of gas. In addition, small bubbles are slower to rise to the liquid surface than large bubbles. A slow rise rate in the liquid means that the gas bubbles and the liquid are in longer contact, thereby increasing the amount of diffusion in the liquid. Thus, smaller bubbles can diffuse more oxygen into the water (e.g., sewage or fish breeding water) or disperse larger quantities of toxic gases, such as radioactive gases, into liquids for disposal. Toxin can be concentrated. This is important in certain applications, such as when dissolving a gaseous fuel into a liquid fuel, because the bubbles are very uniform in size, but the amount of gas that diffuses into the liquid is uniform. It becomes possible to calculate. FIG. 9 has the same configuration as that shown in FIG. 8, except that a liquid 75 is replaced by a gas 80. When the stream of bubbles 79 separates, the liquid 73 forms an outer spherical cover, thereby creating a hollow microdrop 81, which floats within the gas 80. The hollow microdrop 81 has a physical diameter larger than the aerodynamic diameter, that is, an actual diameter. The hollow microdroplets have a very low falling speed in air as compared to liquid microdroplets of the same diameter. Since the hollow microdroplets 81 settle or do not fall in the air in a short time, it becomes possible to inhale them into the lungs. Eventually, the hollow microdrop 81 ruptures, forming many smaller particles, and is sucked deeper into the lung. Thus, it can be seen that the aerodynamic diameter of the hollow microdroplets is very small compared to the actual physical diameter. The creation of hollow microdrops 81 that rupture to form very fine particles can be applied to a wide variety of applications, including internal combustion engines, where fuel 73 (eg, gasoline, (Diesel fuel, jet fuel) are used to form hollow microdroplets, and hollow microdroplets 81 are injected into the combustion chamber, where the hollow microdroplets burst, and smaller particulates are formed and burn. The amount of fuel required to form hollow droplets that rupture to form fine mist is minimized as compared to any of the other existing pneumatic methods.

Emulsion FIG. 10 is similar to FIG. 8 and FIG. However, Feeding Source 71
Supplies a stream of liquid 82 rather than gas 72 as in FIG. 8, in which the liquid may be miscible with liquid 73, but is preferably immiscible therewith. . Further, liquid 73 can be the same or different from liquid 75, but is preferably immiscible with liquid 75. The formation of an emulsion using such a liquid composition has applicability in various fields, in particular, it allows the liquid microparticles formed to have a size ranging from about 1 to about 200 microns. Yes, with a standard deviation of 0.01% in the size difference between one particle and another
And by low. The variation in size between one microparticle and another microparticle can vary up to about 30%, but preferably it is less than ± 5%, more preferably less than ± 1%. This system discharges the liquid 82 out of the outlet orifice 77 and creates a sphere 83 of liquid 82. Each sphere 83 has an actual physical diameter, in which the variance from other spheres 83 is ± 0.01% to ± 30% in standard deviation, preferably 10% or less, more preferably In this case, it is 1% or less. The size of the spheres 83 and the flow rate of the liquid 82 are controlled so that each sphere 83 contains a single microparticle (eg, a single cell) to be tested. The flow of the sphere 83 is flowed through any desired type of sensor or energy source, thus allowing for tight control of the flow rate of the liquid 82 entering the combustion chamber.

(Fuel Emulsion) In order to obtain a two-component fuel, it is important to form small (1 μm to 200 μm) fine particles of uniform size (standard deviation 0.01% to 30%). The emulsion of oil globules 83 can be an aqueous fluid. The system shown in FIG. 10 is also useful in evenly distributing one type of fuel to another. By reducing the particle size and increasing the uniformity, smaller components can be added, with the same effect as adding larger amounts through conventional techniques. In FIG. 10, the liquid 75 is a gas (for example, air) in the combustion chamber of the internal combustion engine.
It can be. The liquid 82 may be water encapsulated by a second liquid 73 that is a hydrocarbon fuel. In that case, the system forms particulates 83 containing water at the center and fuel coated on the outside. When such water / fuel particulates are burned, both the overall combustion chamber temperature and the formation of unwanted emissions are reduced, and the compression ratio of the engine is not reduced or the thermodynamic cycle is reduced. Efficiency is not sacrificed. This system considers temperature as a parameter that can be easily adjusted by the ratio of water to fuel. Adjusting the water / fuel ratio, and thereby adjusting the temperature, allows the thermodynamic cycle to be redesigned, thereby optimizing the power to cleanness ratio. The system can use two different fuels simultaneously. High octane fuel (gasoline) is used as the liquid 73, and low octane fuel (diesel fuel) is included. Any type of low octane low cost fuel sphere 83 is coated with a layer of any type of high octane high value fuel.
As these spheres enter the combustion chamber, the higher octane fuel first burns and reacts, which causes the lower octane fuel to burn. Using this system, the inner octane 87 gasoline nucleus can be coated with 92 octane gasoline to obtain substantially the same performance as 92 octane gasoline at a lower cost. The formation of hollow microdroplets of fuel as shown in FIG. 9 also provides the advantage that when the microdroplets burst in the manner shown in FIG. 9, a fine mist is obtained. As described above, the present invention has been described with reference to the specific embodiments. However, those skilled in the art can make various changes and equivalents without departing from the spirit and scope of the present invention. You need to understand that there is. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective, spirit and scope of the present invention. All of these variations are intended to be within the scope of the claims appended hereto.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the basic components of one embodiment of the present invention with a cylindrical feeding needle as the source of the formulation.

FIG. 2 is a schematic diagram illustrating another embodiment of the present invention with two concentric tubes as the source of the formulation.

FIG. 3 is a schematic diagram of yet another embodiment of the present invention showing a wedge-shaped planar source of the formulation. (A) illustrates a side cross-section showing the interaction of a planar feeding source and a fluid. (B) shows the opening of the pressure chamber as viewed from the front, illustrating a plurality of openings for discharging the atomized product from the device. (C) illustrates an optional channel formed in the planar feeding member. These channels are aligned with the openings in the pressure chamber.

FIG. 4 is a schematic diagram illustrating an embodiment in which a stable capillary microjet is formed and passes through an outlet opening to subsequently form a monodisperse aerosol.

5 is a graph of data plotting the measured values of 350 d _j / d _o vs. Q / Q _o.

FIG. 6A is a schematic view of a usage example of the embodiment shown in FIG. 1 in an injection device. FIG. 2B is a schematic view of a usage example of the embodiment shown in FIG. 1 in the injection device.

FIG. 7 (A) is an example of use of the embodiment shown in FIG. 3, wherein the injection device comprises a circular feeding element disposed in a plurality of concentric pressure chambers. (B) An example of use of the embodiment shown in FIG. 3, in which the injection device comprises a circular feeding element disposed in a plurality of concentric pressure chambers.

FIG. 8 is a schematic diagram of a critical area of a device of the type shown in FIG. 1, showing how gas is wrapped in a liquid and released into the liquid to form a bubble.

FIG. 9 is the same schematic diagram as FIG. 8, but bubbles flow into the gas.

FIG. 10 is the same schematic as FIG. 8, but with two immiscible liquids flowing into the gas.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE , KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZWF terms (reference) 3G066 AB02 AB04 AB05 AB06 AB08 BA02 BA03 CC21 CC26 CC45 CC46 4F033 QA07 QB02Y QB03X QB10X QB14X QD02 QD03 QD19 QE14

Claims (16)

[Claims] 1. A liquid fuel stream characterized by forming a stable capillary microjet over a portion of the stream, wherein the stable microjet is formed by surrounding gases flowing in the same direction. Wherein the gas has a higher velocity than the liquid. 2. The fuel is a hydrocarbon fuel; and the stable capillary microjet is represented by a diameter d _j of the stable capillary microjet, with an allowable error range of ± 10%. Are represented by ≒, the density of the liquid is represented by _l , and a predetermined point A of the stream
Denoting the change in the gas pressure of the gas wrapping the stream by P _{g at this} point A, it is characterized by the equation d _j ≒ {(8 _l ) / ( ² P _g )} ^1/4 Q _A ^1/2 fuel stream of claim 1, wherein it has a diameter d _j which is. 3. The diameter d _j ranges from about 1 micron to about 1 mm.
The portion of the stable capillary microjet has a length ranging from about 1 micron to about 50 mm, wherein the stable capillary microjet is at least partially at least partially separated from the gas in the axial direction of the jet. 3. The fuel according to claim 2, wherein the microjet is maintained by a tangential viscous stress acting on the surface of the jet; and the microjet is further characterized by a slightly parabolic axial velocity profile. stream. 4. A monodisperse aerosol of fuel particulates in air, wherein the particulates have the same diameter ranging from about 5 microns to about 500 microns, wherein certain particulates and other particulates in the aerosol are provided. Monodisperse aerosols having the same diameter with a deviation from about ± 3% to ± 30%. 5. A fuel supply means comprising a fuel inlet port and a fuel outlet port; a pressure chamber for supplying a pressurized fluid to an area enclosing the fuel outlet, the outlet chamber being aligned with the fuel outlet port. A fuel injection nozzle, comprising: a pressure chamber; and means for supplying a second fluid to the pressure chamber, the means having an inlet and an outlet opening for the second fluid. 6. The first means for supplying the fuel is a feeding needle having a cylindrical channel, whereby the inlet port for the first fluid and the outlet port for the first fluid are provided. Wherein the outlet port of the feeding needle has a diameter ranging from about 0.01 mm to about 2 mm, and the outlet opening of the pressure chamber ranges from about 0.01 mm to about 2 mm. An outlet opening of said first means for supplying fuel, having a diameter, is located in a range from about 0.01 mm to about 1 mm from an outlet port of said second fluid of said pressure chamber. 6. The device according to claim 5, characterized in that: 7. The first means for supplying fuel comprises: a surface of a first planar member;
A planar channel formed between surfaces of a second planar member disposed parallel to the surface of the first planar member, wherein the pressure chamber comprises a plurality of pressure fluid outlet ports. 6. The device according to claim 5, characterized in that: 8. The method of claim 1, wherein the device inserts a first fluid therein having a kinetic viscosity in the range of about 10 ^-4 to about 1 kg / m / sec, wherein the fuel further comprises hydrocarbons. 7. The device according to claim 6, wherein: 9. A method for producing an atomized fuel, comprising: extruding a first fluid through a channel of a feeding source in a manner to discharge the first fluid from an outlet opening; Is discharged from the pressure chamber through an outlet orifice in front of the flow path of the first fluid discharged from the outlet opening of the feeding source. Extruding; wherein a stable fluid-fluid interface is maintained, wherein the first fluid is
Forming a stable capillary jet converged by the fluid at the outlet orifice of the pressure chamber; wherein at least one of the first fluid and the second fluid is a hydrocarbon. How to produce fuel. 10. The method of claim 1, wherein the first fluid is a liquid and the second fluid is a gas, wherein the liquid has a viscosity in a range from about ^10-4 to about 1 kg / m / sec. 10. The method of claim 9, wherein the method is characterized in that: 11. The liquid has a viscosity ranging from about 0.3 × 10 ⁻³ to about 5 × 10 ⁻² kg / m / sec, wherein the fluid is passed through the channel at about 0.01 nl / kg. Pumping at a rate ranging from about 100 to 500 m / s through the opening of the pressure chamber; and feeding the gas at a rate ranging from about 100 to 500 m / s; Is a cylindrical channel, wherein the liquid is approximately
Discharged from an outlet opening having a diameter ranging from 0.1 mm to about 0.4 mm, the opening of the pressure chamber having a diameter ranging from about 0.1 mm to about 0.25 mm, wherein the outlet opening of the channel has 11. The method according to claim 10, wherein the method is arranged just in front. 12. The first fluid comprises water, and the second fluid comprises a liquid hydrocarbon fuel immiscible with water, wherein the stable capillary microjet is coated with a sphere of hydrocarbon fuel. 10. The method of claim 9, wherein the water splits into water spheres. 13. The method according to claim 13, wherein the first fluid comprises a low octane fuel.
10.The fluid of claim 9, wherein said fluid comprises a high octane fuel, wherein said stable capillary microjets split into low octane fuel spheres coated by high octane fuel spheres. Method. 14. The method according to claim 12, wherein the coated spheres each have substantially the same diameter with a standard deviation ranging from 0.01% to 30%. 15. The method of claim 14, wherein the coated spheres have substantially the same diameter with a standard deviation of 1% or less. 16. The first fluid is a gas and the second fluid is a liquid hydrocarbon fuel, in which a stream formed by the first and second fluids splits to a size Forming substantially uniform hollow microdroplets in size with a standard deviation of diameters of about 5% or less, wherein the hollow microdroplets rupture to form fine mist of hydrocarbon fuel. 10. The method according to claim 9, wherein: