Fuel injection nozzle and method of use

• US 6,189,803 B1
• Filed: 11/13/1998
• Issued: 02/20/2001
• Est. Priority Date: 05/13/1996
• Status: Expired due to Term

• Current Assignee: Universidad de Sevilla
• Original Assignee: University of Seville
• Inventors: Ganan-Calvo, Alfonso
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): Nguyen, Dinh Q.
• Application Number:
  US09/191,787
• Time in Patent Office: 830 Days
• Field of Search: 239/5, 239/8, 239/86, 239/410, 239/411, 123/531, 123/585
• US Class Current: 239/5
• CPC Class Codes: A61M 15/025 Bubble jet droplet ejection devices
• CPC Class Codes: B01F 25/30 Injector mixers mixing by creating vortex flow B01F25/10
• CPC Class Codes: B01F 33/3011 using a sheathing stream of a fluid surrounding a central stream of a different fluid, e.g. for reducing the cross-section of the central stream or to produce droplets from the central stream
• CPC Class Codes: B05B 7/0475 with means for deflecting the peripheral gas flow towards the central liquid flow B05B7/0458 takes precedence
• CPC Class Codes: B05B 7/061 with several liquid outlets discharging one or several liquids
• CPC Class Codes: B05B 7/065 an inner gas outlet being surrounded by an annular adjacent liquid outlet
• CPC Class Codes: B05B 7/066 with an inner liquid outlet surrounded by at least one annular gas outlet
• CPC Class Codes: B05B 7/0884 the outlet orifices for jets constituted by a liquid or a mixture containing a liquid being aligned
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: F02M 43/04 Injectors peculiar thereto
• CPC Class Codes: F02M 67/10 Injectors peculiar thereto, e.g. valve less type
• CPC Class Codes: F02M 69/047 injectors with air chambers, e.g. communicating with atmosphere for aerating the nozzles F02M69/325 takes precedence
• CPC Class Codes: F02M 69/08 characterised by the fuel being carried by compressed air into main stream of combustion-air
• CPC Class Codes: F23D 11/106 medium and fuel meeting at the burner outlet
• CPC Class Codes: G01N 15/1409 Handling samples, e.g. injecting samples
• CPC Class Codes: G01N 2015/1406 Control of droplet point

Abstract

Atomized particles within a desired size range (e.g., 1 micron to about 5 microns) are produced from two immiscible fluids, the first a fuel source containing the formulation to be atomized, and a second fluid source which is contained in a pressure chamber surrounding at least the area where the first liquid is to be provided. The invention provides a method for the formation of small, relatively uniform fuel particles for use in internal combustion engines and a nozzle-type apparatus for providing the particles to a combustion chamber.

Claims

1. A liquid hydrocarbon fuel stream characterized by forming a stable microjet over a portion of the stream, wherein the stable microjet is formed by a surrounding gas flowing in the same direction, said gas having a greater velocity than the liquid wherein the stable microjet comprises a diameter d_j at a given point A in the stream characterized by the formula:

$d_j\approx <br><br>{\left(\frac{8<br><br>{\mathrm{\rho <br><br>}}_l}{{\mathrm{\Pi <br><br>}}^2<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_g}\right)}^{\mathrm{¼<br><br>}}<br><br>Q^{\mathrm{½<br><br>}}$

wherein d_j is the diameter of the stable microjet, ≈

indicates approximately equally to where an acceptable margin of error is ±

10%, Q is the liquid flow rate, ρ

₁ is the density of the liquid and Δ

P_g is change in gas pressure of gas surrounding the stream at the point A.

2. The fuel stream of claim 1, wherein d_j is a diameter in a range of about 1 micron to about 1 mm, and the stable jet portion has a length in a range of from about 1 micron to about 50 mm, and wherein the stable microjet is maintained, at least in part, by tangential viscous stresses exerted by a gas on a surface of the jet in an axial direction of the jet.

3. The fuel stream of claim 1, wherein the microjet is further characterized by a slightly parabolic axial velocity profile.

4. A monodisperse aerosol of fuel particles in air, the particles characterized by having the same diameter with a deviation in diameter from one particle to another in a range of from about ±

3% to about ±

30%, wherein the particles are formed from the stable microjet by the effect of capillary instability of the microjet, and wherein the stable microjet comprises a diameter d_j at a given point A in the stream characterized by the formula;

$d_j\approx <br><br>{\left(\frac{8<br><br>{\mathrm{\rho <br><br>}}_l}{{\mathrm{\Pi <br><br>}}^2<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_g}\right)}^{\mathrm{¼<br><br>}}<br><br>Q^{\mathrm{½<br><br>}}$

wherein d_j is the diameter of the stable microjet, ≈

indicates approximately equally to where an acceptable margin of error is ±

10%, Q is the liquid flow rate, ρ

₁ is the density of the liquid and Δ

P_g is change in gas pressure of gas surrounding the stream at the point A.

5. The aerosol of claim 4, wherein a given particle in the aerosol has a diameter in a range of about 5 microns to about 500 microns and wherein other particles in the aerosol have the same diameter as the given particle with a deviation of about ±

3% to about ±

30%.

6. A fuel injection nozzle, comprising:

a means for providing fuel, said means comprising a fuel entrance port and a fuel exit port; and

a pressure chamber for providing a pressurized fluid to an area surrounding the fuel exit port,

wherein the exit port has a diameter in the range of from about 0.01 mm to about 2 mm, and the pressure chamber exit opening has a diameter in the range of about 0.01 mm to about 2 mm, and further wherein the nozzle in operation creates a stable microjet of fuel having a diameter d_j at a given point A in the stream characterized by the formula;

$d_j\approx <br><br>{\left(\frac{8<br><br>{\mathrm{\rho <br><br>}}_l}{{\mathrm{\Pi <br><br>}}^2<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_g}\right)}^{\mathrm{¼<br><br>}}<br><br>Q^{\mathrm{½<br><br>}}$

wherein d_j is the diameter of the stable microjet, ≈

indicates approximately equally to where an acceptable margin of error is ±

10%, Q is the liquid flow rate, ρ

₁ is the density of the liquid and Δ

P_g is change in gas pressure of gas surrounding the stream at the point A.

7. The fuel injection nozzle of claim 6, having inserted therein fuel having a dynamic viscosity in the range of from about 10⁻

4 to about 1 kg/m/sec and wherein the fuel is a hydrocarbon.

8. A fuel injection apparatus comprising the fuel injection nozzle of claim 6.

9. An internal combustion engine comprising the fuel injection apparatus of claim 8.

10. A method for producing atomized fuel, comprising the steps of:

forcing a liquid hydrocarbon fuel through a channel of a feeding source in a manner which causes the liquid to be expelled from an exit opening;

forcing a gas through a pressure chamber in a manner which causes the gas to exit the pressure chamber from an exit orifice downstream of a flow path of the liquid expelled from the exit opening of the feeding source;

wherein a stable liquid-gas interface is maintained and the liquid hydrocarbon fuel forms a stable microjet wherein the stable microjet comprises a diameter d_j at a given point A in the stream characterized by the formula;

$d_j\approx <br><br>{\left(\frac{8<br><br>{\mathrm{\rho <br><br>}}_l}{{\mathrm{\Pi <br><br>}}^2<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_g}\right)}^{\mathrm{¼<br><br>}}<br><br>Q^{\mathrm{½<br><br>}}$

wherein d_j is the diameter of the stable microjet, ≈

indicates approximately equally to where an acceptable margin of error is ±

10%, Q is the liquid flow rate, ρ

₁ is the density of the liquid and Δ

P_g is change in gas pressure of gas surrounding the stream at the point A.

11. The method of claim 10, wherein the liquid hydrocarbon fuel has a viscosity in a range of from about 10⁻

4 to about 1 kg/m/sec.

12. The method of claim 10, wherein the liquid hydrocarbon fuel has a viscosity in a range of from about 0.3×

10<sup>−

3</sup> to about 5×

10<sup>−

2</sup> kg/m/sec, and wherein the liquid is forced through the channel at a rate in a range of about 0.01 nl/sec to about 100 μ

l/sec, and wherein the gas is forced through the opening of the pressure chamber at a rate in the range of from about 100 to 500 m/sec.

13. The method of claim 10, wherein the liquid hydrocarbon fuel is forced through the channel at a rate in a range of about 1 nl/sec to about 10 μ

l/sec, and wherein the gas is forced through the opening of the pressure chamber at a rate in the range of from about 50 m/sec to about 2000 m/sec.

14. The method of claim 10, wherein the feeding source is a cylindrical channel and the liquid hydrocarbon fuel is expelled from an exit opening having a diameter in the range of from about 0.1 mm to about 0.4 mm and wherein the opening in the pressure chamber has a diameter in the range of about 0.1 mm to 0.25 mm and is positioned directly in front of the exit opening of the channel.

15. The method of claim 10, wherein the stable microjet exits the pressure chamber and splits by the effect of capillary instability to form uniform particles having a relative size deviation in a range of from about ±

3% to about ±

30%.