Acoustic Nozzle

Abstract

A nozzle for finely dispersing a liquid in a gas stream, usually air or steam, has therein a reverberation chamber for producing acoustic energy in the gas stream. The gas then flows through a plurality of tubular passages which are intersected by tubular passages carrying therethrough a liquid to be nebulized, said liquid usually being oil. The nozzle is particularly useful for nebulizing oil in preparation for combustion thereof.

Description

BACKGROUND OF THE INVENTION

A variety of nozzles have been devised in which a rapidly moving gas stream is caused to generate pressure waves at sonic or supersonic frequencies for the purpose of nebulizing a liquid. In the process, the energy in the pressure waves is transferred to the liquid causing the liquid stream to break up into droplets which present a large surface for combustion or other types of reaction.

The energy transferred in the process is substantial, so that improvements in nozzle design which results in an increase in the efficiency of atomization can yield substantial savings. This is particularly the case where large quantities of fluid must be dispersed.

Heretofore, attempts to increase the efficiency of atomization by nozzles had been directed at modifying the shape of the axial passage through which the gas stream flows. In general, modifications have consisted of contractions or expansions of the interior of the nozzle so that flow through the nozzle may be successively convergent, constant in cross section, and divergent. Although resonant chambers may be provided by such an arrangement, the results have been less than optimum as measured by efficiency of dispersion, the required pressure at which the gas must be supplied to the nozzle and the quantity of gas which must be supplied to disperse a given amount of liquid.

SUMMARY OF THE INVENTION

A high efficiency of dispersion of a liquid is obtained by the use of a nozzle having a resonant chamber therein from which the gas flows through a plurality of tubular passages to the exterior of the nozzle. Simultaneously, oil flows through a plurality of tubular passages equal in number to those carrying the gas stream to the exterior of the nozzle, each of the oil passages intersecting one of the gas passages proximate the surface of the nozzle. The energy of the gas stream atomizes the flowing liquid into fine droplets.

In a second embodiment, an axial stem is disposed centrally within the resonance chamber, modifying the resonant chamber into an annulus for the purpose of increasing the efficiency of energy transfer by the resonant chamber.

Accordingly, an object of the present invention is to provide an improved nozzle for atomizing a liquid stream by means of a gas stream.

Another object of the present invention is to provide an improved nozzle for generating acoustic energy within a gas stream to be used for atomizing a liquid.

A further object of the present invention is to provide an improved nozzle having a resonant chamber with an axial stem therethrough for the purpose of generating acoustic energy at high efficiency for the purpose of atomizing a liquid stream.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is an end view of a nozzle in accordance with the present invention;

FIG. 2 is a cross-sectional view taken along the line 2--2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 2; and

FIG. 4 is a cross-sectional view of another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A nozzle in accordance with the present invention is generally indicated by the reference numeral 11. Gas, which is usually air or steam, is brought to nozzle 11 through inner tube 12. In the embodiment shown in FIG. 2 nozzle 11 is joined to the inner tube 12 by threaded section 13. Nozzle 11 is positioned axially with respect to inner tube 12 by seating of end 14 on shoulder 15. Gas flowing at high rate through inner tube 12 reaches resonant chamber 20 in which part of the energy of flow is converted into acoustic energy. Chamber 20 terminates in an end 16. The gas carrying the acoustic energy departs resonant chamber 20 through tubular passages 17.

Simultaneously, the liquid to be dispersed, usually oil, flows through annular passage 18 defined by outer tube 19 and inner tube 12. The flowing oil on leaving annulus 18 enters tubular passages 21 which intersect gas passages 17 proximate surface 22 of nozzle 11. Atomization of the flowing liquid takes place at the intersection between the plurality of passages 17 and 21 at high efficiency.

In the embodiment shown in FIGS. 1 thru 3, outer tube 19 is connected gas-tightly with nozzle 11 by the use of gasket 23. Axial location of nozzle 11 with respect to outer tube 19 results from seating of shoulder 24 on end 26 of outer tube 19. For purposes or removal of nozzle 11 from inner tube 12, nozzle 11 is provided with flats 27.

In the embodiment shown in FIG. 4, stem 28 is centrally disposed within passageway 29 leading to resonant chamber 20. Chamber 20 terminates in an end 16. Stem 28 has a flange 31 which is held between end 32 of inner tube 12 and shoulder 33 of nozzle 11. Ducts 34 in flange 31 provide for the flow of gas from inner tube 12 to resonant chamber 20. Upper end 36 of stem 28 seats within aperture 37 provided in nozzle 11.

The purpose of the stem 28 is to increase the efficiency of resonant chamber 20 in producing acoustic energy in the gas flowing therethrough. Where it is desired to use the nozzle of FIG. 4 without stem 28, the embodiment of FIG. 2 results.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Claims

What is claimed is:

1. An improvement in an acoustic nozzle for nebulizing oil in preparation for combustion thereof, said acoustic nozzle having a central axis and being supplied with a gas through an inner tube and with oil through an annulus defined by said inner tube and an outer tube surrounding said inner tube, wherein said improvement comprises an axial resonant chamber in said nozzle for introducing acoustic energy into said gas, said chamber being continuous with said inner tube and supplied with gas therefrom, a plurality of first tubular passages leading from said inner tube adjacent said resonant chamber to the exterior surface of said nozzle for conducting said gas containing acoustic energy to said exterior surface of said nozzle, and a plurality of second tubular passages, each of said second tubular passages having an inner and an outer end, all of said inner ends making connection with said annulus for receiving flowing oil, and each of said outer ends intersecting one of said first tubular passages at a region proximate the exterior surface of said nozzle, thereby serving to bring together gas and oil streams for nebulizing said oil by said acoustic energy in said gas stream.

2. The improvement as defined in claim 1, wherein the exterior surface of said nozzle is frustoconical in shape.

3. The improvement as defined in claim 2, wherein the outer ends of said tubular passages lie on a circle the plane of which is perpendicular to the axis of said nozzle.

4. The apparatus as defined in claim 1, wherein a stem is located axially in said resonant chamber in order to increase the efficiency of acoustic energy transfer to said gas.

5. The apparatus as defined in claim 4 wherein said stem has a flange at its upstream end, said flange being held between said nozzle and the downstream end of said inner tube, said flange having passages therethrough connecting said inner tube with said nozzle for flow of gas therethrough.

6. The improvement as defined in claim 1, wherein the number of first tubular passages equals the number of second tubular passages.

7. An acoustic nozzle having a downstream exit end and an upstream inlet end comprising a central passage extending between said inlet and exit ends for receiving gas supplied at said inlet end, a resonant chamber communicating with said central passage and located adjacent said exit end, a plurality of exit passages extending between said central passage and the exterior of said nozzle to deliver gas outwardly of said nozzle at acoustic energies from said central passage, said exit passages communicating with said central passage upstream of the end of said resonant chamber, and a plurality of fuel passages within said nozzle for receiving fuel to be nebulized, said fuel passages having inlet and outlet ends, said outlet ends communicating with said exit passages intermediate the ends thereof.

8. An acoustic nozzle as claimed in claim 7 wherein said central passage includes a stem positioned centrally thereof and extending into said resonant chamber.

9. An acoustic nozzle as claimed in claim 8 wherein said stem carries radially extending flanges at the upstream end thereof for segmenting a portion of said central passage intermediate the ends thereof.