Swirling flow-blurring atomizer

Abstract

An atomizer includes an endcap having a nozzle; an annular sidewall extending outward from a surface of the endcap and situated radially outward from the nozzle; and a plurality of vanes extending radially inward from the sidewall and axially outward from the endcap, the vanes being set at a non-zero angle of incidence to the sidewall. The annular sidewall and endcap define an fluid chamber between an inlet and the nozzle, and flow from the inlet to the nozzle is at least partially directed through passageways between the vanes, and the flow is imparted with swirling motion from the vanes.

Claims

1. An atomizer configured to atomize liquids passed therethrough, the atomizer comprising: an endcap comprising an annular wall extending longitudinally along an axial centerline of the atomizer from an upstream end to a downstream end with respect to a flow of fuel through the atomizer and a planar wall that extends radially inward from the downstream end of the annular wall to an opening; a nozzle situated within the endcap; and a plurality of swirl vanes, wherein a first end radially outward end of each swirl vane in the plurality of swirl vanes contacts a radially inward surface of the annular wall, wherein each swirl vane in the plurality of swirl vanes extends radially inward from the radially inward surface of the annular wall towards the axial centerline of the atomizer and terminates at a radially inward end, wherein a downstream end of each swirl vane contacts an upstream surface of the planar wall wherein each swirl vane extends axially upstream from the upstream surface of the planar wall and terminates at an upstream end, and the radially inward end of each swirl vane in the plurality of swirl vanes and the upstream end of each swirl vane of the plurality of swirl vanes do not contact any surface, wherein the plurality of swirl vanes are set at a non-zero angle of incidence to the endcap, wherein the endcap extends farther radially inward from the annular wall than the swirl vanes extend radially inward from the annular wall, wherein the endcap defines an inner fluid chamber between a fluid inlet and the nozzle, wherein flow from the inlet to the nozzle is at least partially directed through passageways between the plurality of swirl vanes, and wherein the flow is imparted with swirling motion due to a tangential momentum imposed by the plurality of swirl vanes.

2. The atomizer of claim 1, wherein the nozzle is centered with respect to the endcap.

3. The atomizer of claim 1, wherein the angle of incidence is 32 degrees.

4. The atomizer of claim 1, wherein the plurality of swirl vanes extend radially inward from the radially inward inner surface of the annular wall at a 30 degree angle.

5. The atomizer of claim 1, wherein the tangential momentum is configured to increase a mixing between a plume sprayed from the endcap and air surrounding the plume.

6. An atomizer, comprising: an endcap comprising an annular wall extending longitudinally along an axial centerline of the atomizer from an upstream end to a downstream end with respect to a flow of liquid through the atomizer and a planar wall that extends radially inward from the downstream end of the annular wall to an opening; a spray nozzle situated within the endcap, wherein the spray nozzle is configured to pass the liquid through the spray nozzle; and a plurality of swirl vanes, wherein a radially outward end of each swirl vane in the plurality of swirl vanes contacts a radially inward surface of the annular wall, wherein each swirl vane in the plurality of swirl vanes extends radially inward from the radially inward surface of the annular wall towards the axial centerline of the atomizer and terminates at a radially inward end, wherein a downstream end of each swirl vane contacts an upstream surface of the planar wall, wherein each swirl vane extends axially upstream from the upstream surface of the planar wall and terminates at an upstream end, and the radially inward end of each swirl vane in the plurality of swirl vanes and the upstream end of each swirl vane of the plurality of swirl vanes do not contact any surface, wherein the plurality of swirl vanes are configured to define a plurality of swirled passages, wherein the endcap extends farther radially inward from the annular wall than the swirl vanes extend radially inward from the annular wall, wherein the plurality of swirled passages are configured to impart a swirling motion to gas passing through the plurality of swirled passages, and wherein the plurality of swirl vanes and the spray nozzle are configured to mix the liquid with the gas, thereby atomizing the liquid.

7. The atomizer of claim 6, wherein the plurality of swirl vanes comprise 8 swirl vanes.

8. The atomizer of claim 6, wherein the plurality of swirl vanes extend radially inward from the radially inward inner surface of the annular wall at a 30 degree angle.

9. The atomizer of claim 6, wherein the plurality of swirl vanes are configured to impose a tangential momentum on the gas passing through the plurality of swirled passages.

10. The atomizer of claim 6, wherein the plurality of swirl vanes are configured to impose a tangential momentum on the gas, and wherein the tangential momentum is configured to increase a mixing between a plume sprayed from the endcap and air surrounding the plume.

11. The atomizer of claim 6, wherein the nozzle is centered with respect to the endcap.

12. An atomizer, comprising: an endcap comprising an annular wall extending longitudinally along an axial centerline of the atomizer from an upstream end to a downstream end with respect to a flow of liquid through the atomizer and a planar wall that extends radially inward from the downstream end of the annular wall to an opening; a spray nozzle situated within the endcap, wherein the spray nozzle is configured to pass the liquid through the spray nozzle; and a plurality of swirl vanes, wherein a radially outward end of each swirl vane in the plurality of swirl vanes contacts a radially inward surface of the annular wall, wherein each swirl vane in the plurality of swirl vanes extends radially inward from the radially inward surface of the annular wall towards the axial centerline of the atomizer and terminates at a radially inward end, wherein a downstream end of each swirl vane contacts an upstream surface of the planar wall, wherein each swirl vane extends axially upstream from the upstream surface of the planar wall and terminates at an upstream end, and the radially inward end of each swirl vane in the plurality of swirl vanes and the upstream end of each swirl vane of the plurality of swirl vanes do not contact any surface, wherein the plurality of swirl vanes are configured to define a plurality of swirled passages, wherein the endcap extends farther radially inward from the annular wall than the swirl vanes extend radially inward from the annular wall, wherein the plurality of swirled passages are configured to impart a swirling motion to gas passing through the plurality of swirled passages, and wherein the plurality of swirl vanes and the spray nozzle are configured to mix the liquid with the gas, thereby atomizing the liquid, wherein the plurality of swirl vanes are configured to impose a tangential momentum on the gas passing through the plurality of swirled passages, and wherein the tangential momentum is configured to increase a mixing between a plume sprayed from the endcap and air surrounding the plume, wherein the nozzle is centered with respect to the endcap.

13. The atomizer of claim 12, wherein the plurality of swirl vanes comprise 8 swirl vanes.

14. The atomizer of claim 12, wherein the plurality of swirl vanes extend radially inward from the radially inward inner surface of the annular wall at a 30 degree angle.

15. The atomizer of claim 12, wherein the plurality of swirl vanes are set at a non-zero angle of incidence to the endcap.

16. The atomizer of claim 12, wherein the angle of incidence is 32 degrees.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a bottom view of an exemplary atomizer showing the swirl vanes extending into the stream of gas;

(2) FIG. 2 shows a cross-sectional schematic view of an exemplary atomizer showing swirl vanes extending into the stream of gas.

DETAILED DESCRIPTION

(3) To produce a wider, hollower plume than conventional atomizers, swirl vanes can be added to impart tangential momentum to the atomizing air at any location upstream of the liquid injection to increase rotation as it approaches the exit orifice, which propels droplets outward from the plume center to form a broader, more hollow, conical spray plume that will prevent flame lifting and the associated combustion dynamics. Preliminary demonstrations with 30 swirl vanes have shown to produce broader plumes with better mixing behavior than the strait atomizer.

(4) Referring first to FIGS. 1 and 2, an exemplary atomizer 100 includes a spray nozzle 110 configured to atomize liquids passed therethrough. The spray nozzle is situated in an endcap 120, preferably in the center of the endcap. An annular sidewall 130 extends axially outward from the inner surface of the endcap, and is situated radially outward from the nozzle, circumscribing it. A plurality of vanes 140 extend radially inward from the sidewall 130 and axially outward from the endcap 120. The vanes are set at a non-zero angle of incidence to the sidewall. An exemplary embodiment has 8 swirl vanes 140. The annular sidewall 130 and endcap 120 define an inner fluid chamber 150 between a fluid inlet 160 and the nozzle 110. Fluid (preferably gas) flow from the inlet to the nozzle is at least partially directed through passageways 155 between the plurality of vanes 140, and the gaseous flow is, therefore, imparted with swirling motion from the plurality of vanes 140. A central tube 170 carries fuel or other fluid to a point adjacent the nozzle 11, where it is mixed with the flow of gas and atomized.

(5) Nozzle tests have been performed with water and air to determine the spray behavior of exemplary atomizer tips, as shown in FIGS. 1 and 2. The relevant parameters for these tests are the air flow rate, liquid flow rate, and the mass-based air-liquid ratio (ALR), which is a ratio of the mass flow of the air to the mass flow of the liquid.

(6) Plume tests reveal that a conventional nozzle produces a plume spreading angle of 22, while an exemplary nozzle with 30 radial swirl vanes produces a plume with a spread of 32, resulting in a 31% increase.

(7) The tangential momentum imposed by the swirl vanes produces a substantial increase in the plume angle that allow exemplary atomizers to be utilized for any application that requires a broader spray cone, such as, for example, spray burners, coating applications, fire suppression, and water-efficient spray washing.

(8) The tangential momentum imposed by the swirl also increases the turbulent mixing between the plume and the surrounding air. This change assists in broadening the spray plume droplets to a wider region and in the formation and anchoring of stable combustion.

(9) Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a means) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.