1. Field of the Invention
The subject disclosure relates to fine spray nozzles, and more particularly to nozzles which create a vortex to form a fine spray.
2. Background of the Related Art
Traditionally, fine spray nozzles utilize either an impingement or an air-atomizing design to produce small droplets. Impingement is simply directing the flow of fluid through an orifice onto a pin to generate the spray. A primary disadvantage of impingement designs is that the target pin is difficult to align and can easily become damaged or misaligned resulting in poor performance. Moreover, a target pin may become dislodged and create damage downstream. Another drawback associated with impingement nozzles is that the orifice/pin feature tends to wear over the life of the nozzle which, in turn, may adversely affect spray pattern and drop size over the life of the nozzle. Air-atomizing designs are another well-known type of design which utilizes a source of pressurized air to atomize the fluid. A primary disadvantage of the air-atomizing designs is the increased expense of providing and maintaining the source of pressurized air.
In view of the above, several nozzles which utilize a swirling flow have been developed as alternatives. Swirling flow nozzles convert the head pressure of the fluid into kinetic energy within a swirl chamber. The discharged fluid disintegrates into droplets from the centrifugal force. Exemplary swirl flow nozzles are shown in U.S. Pat. Nos. 3,771,728; 3,532,271; and 6,186,417. Heretofore, several factors have limited the applicability of swirl flow nozzles, including: poor tolerance when machining the materials from which the nozzles are made; the spray patternation quality deteriorates as the size of the swirl chamber decreases; clogging due to smaller dimensions; and small parts become difficult to handle and assemble.
There is a need, therefore, for an improved small spray nozzle that overcomes one or more of the above-described drawbacks of the related art.
The present invention is directed to a spray nozzle comprising a body defining an inlet aperture and an outlet aperture. An orifice disk of the spray nozzle is receivable within the body adjacent to the outlet opening and includes a sheet material substrate defining a first surface formed on one side of the substrate, a second surface formed on an opposite side of the substrate relative to the first surface, a side surface extending between the first and second surfaces and defining a peripheral edge of the orifice disk, and a spray orifice extending through a first region of the substrate spaced inwardly relative to the peripheral edge. A swirl disk of the nozzle is receivable within the body adjacent to the orifice disk and includes a sheet material substrate defining a first surface formed on one side of the substrate, a second surface formed on an opposite side of the substrate relative to the first surface, and a side surface extending between the first and second surfaces and defining a peripheral edge of the swirl disk. A swirl chamber of the swirl disk is defined by a first aperture extending through a first region of the substrate spaced inwardly relative to the peripheral edge, and a swirl inlet is defined by a second aperture formed through a second region of the substrate extending between the swirl chamber and peripheral edge. A plug of the nozzle is receivable within the body adjacent to the swirl disk for retaining the swirl disk and orifice disk within the body. The plug defines a fluid flow path coupled in fluid communication between the inlet of the body and the inlet of the swirl disk for directing fluid flowing through the inlet of the body into the swirl chamber and, in turn, imparting a swirling flow to the fluid prior to discharging the fluid through the spray orifice in a spray pattern emanating therefrom.
The present invention also is directed to a method of forming a swirl disk of a spray nozzle, wherein the method includes the steps of: (1) providing a sheet of material for forming the swirl disk therefrom; and (2) forming at least one swirl disk from the sheet of material by (i) removing material about a peripheral portion of the swirl disk and, in turn, forming a peripheral edge of the swirl disk, (ii) removing material from at least one first region of the swirl disk spaced inwardly relative to the peripheral edge of the swirl disk and, in turn, forming a first aperture extending through the first region and defining a swirl chamber, and (iii) removing material from at least one second region of the swirl disk extending between the swirl chamber and peripheral edge of the swirl disk and, in turn, forming a second aperture extending through the second region and defining a flow inlet to the swirl chamber.
In a currently preferred embodiment of the present invention, the method further comprises the step of providing an orifice disk for use with the swirl disk of the spray nozzle. The step of providing the orifice disk includes the steps of: (1) providing a sheet of material for forming the orifice disk therefrom; and (2) forming at least one orifice disk from the sheet of material by (i) removing material about a peripheral portion of the orifice disk and, in turn, forming a peripheral edge of the orifice disk, and (ii) removing material from at least one first region of the orifice disk spaced inwardly relative to the peripheral edge of the orifice disk and, in turn, forming a first aperture extending through the first region and defining a spray orifice.
In a currently preferred embodiment of the present invention, each step of removing sheet material is performed by etching. In addition, the first and second surfaces of the swirl disk are preferably symmetrical about a plane perpendicular to the axis of the spray nozzle. Also in a currently preferred embodiment of the present invention, the first and second surfaces of the swirl disk are substantially planar throughout. In yet another currently preferred embodiment of the present invention, the first and second surfaces of the swirl disk are substantially identical.
One advantage of the present invention is that the nozzles utilize a vortex to create a fine mist, thereby enabling a reduction in manufacturing complexity and maintenance costs while permitting increased reliability and performance in comparison to prior art impingement and/or air-atomizing nozzles.
Another advantage of a currently preferred embodiment of the present invention is that it permits the exchange of variously configured swirl and orifice disks to fine tune nozzle performance for a specific application.
It should be appreciated that the present invention can be implemented and utilized in numerous ways, including without limitation as a process, an apparatus, a system, a device (including, for example, a nozzle assembly, a swirl disk and an orifice disk) and a method for applications now known and later developed. These and other unique features of the invention disclosed herein will become more readily apparent from the following detailed description of preferred embodiments, claims and the accompanying drawings
So that those having ordinary skill in the art to which the disclosed invention appertains will more readily understand how to make and use the same, reference may be had to the drawings wherein:
The present invention overcomes many of the prior art problems associated with spray nozzles. The advantages, and other features of the nozzles disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain preferred embodiments taken in conjunction with the drawings which set forth representative embodiments of the present invention and wherein like reference numerals identify similar structural elements.
Referring to
The nozzle 10 is scalable to a number of different flow rates, droplet sizes and spray angles. For example, the nozzle 10 may be configured to function under very low flow rates (less than about 0.05 gpm) and still produce a population of droplets with a Sauter Mean Diameter on the order of about 20 microns at pressures of about 1000 psi. As a result, for systems in which the nozzle of the present invention is installed, the required flow of liquid can be achieved with reduced initial costs for pumping equipment and/or lower operating costs in comparison to such systems employing prior art spray nozzles. Exemplary pipe sizes are ⅛″ and ¼″ pipes. Exemplary applications for the nozzle 10 include, without limitation, turbine cooling, fire misting, livestock cooling, gas quenching, humidification, evaporative cooling, coating, spray drying of low abrasion liquids, area misting, cooling of castings, direct contact cooling, and the like.
Referring to
The swirl disk 22 also forms an inlet 27 in fluid communication with the central hollow 28 for channeling fluid thereto. The inlet 27 expands gradually from a throat 26 at the central aperture towards the periphery of the swirl disk 22. The throat 26 is determined at the point where the straight portions 25 of the inlet 27 become arcuate. The swirl disk start radius 29 is the minimum radius of the central hollow or swirl chamber 28 of the swirl disk 22. Among other parameters, varying the throat ratio, which is the ratio of the throat 26 to the swirl start radius 29, will vary the shape of the vortex formed within the central hollow 28. Preferably, the throat ratio is within the range of about 3:5 to about 11:10.
Referring to
In the illustrated embodiment of the present invention, the orifice disk 20 and swirl disk 22 are manufactured using a photochemical etching process of a type known to those of ordinary skill in the pertinent art that results in very thin, tight tolerance components preferably formed of stainless steel. One advantage of the photochemical machining process is that it allows the swirl and orifice disks to be etched from sheet material substrates in a manner that obtains sufficiently tight tolerances to produce extremely small droplet sizes (e.g., droplets with a Sauter Mean Diameter on the order of about 20 microns at about 1000 psi and at flow rates of less than or equal to about 0.05 gpm) that could not be achieved with certain prior art single fluid whirl nozzles. Yet another advantage is that the photochemical machining process is a relatively efficient and low-cost method for producing large volumes of relatively tight tolerance components, such as the swirl and orifice disks. In the illustrated embodiment of the present invention, the orifice disk 20 defines a thickness of approximately 0.005 inches, and the thickness of the orifice disk is preferably within the range of about 0.005 to about 0.020 inches. Similarly, the swirl disk defines a thickness of approximately 0.005 inches, and the thickness of the swirl disk is preferably within the range of about 0.005 to about 0.020 inches. Exemplary etching techniques are shown in U.S. Pat. No. 5,740,967 to Simmons et al. and U.S. Pat. No. 5,951,882 to Simmons et al., each of which is incorporated herein by reference. It is also envisioned that the disks 20, 22 can be fabricated by any of numerous other techniques or processes that are currently or later become known, including metal injection molding, laser cutting and fine stamping. In addition, although the orifice and swirl disks 20 and 22, respectively, are etched from stainless steel sheets, these disks may be formed from any of numerous other types of metals or other materials that are currently or later become known for performing the functions of the respective disk, and/or as may be required by a particular application or as may be permitted by a particular manufacturing technique or process.
Referring to
In operation, the nozzle 10 is mounted on a pipe or other structure such that liquid enters the internal bore 36 of the plug 30. The liquid exits the internal bore 36 via the set of exit orifices 38. Accordingly, the liquid travels into the annulus area 34 substantially perpendicularly to the axis of the nozzle 10. The annulus area 34 is in fluid communication with the inlet 27 at the periphery of the swirl disk 22 so that the liquid within the annulus area 34 enters the inlet 27 of the swirl disk 22. As the liquid passes through the throat 26 of the inlet 27, the liquid enters the central aperture or swirl chamber 28 of the swirl disk 22 where a vortex is formed. Then, the liquid passes through the central aperture 24 of the orifice disk 20 and out of the outlet 16 of the body 12. Upon exiting the body 12, the turbulence of the swirling vortex forces the liquid to disintegrate into a fine mist.
Referring to
Referring to
Referring to
Referring to
In operation, the liquid enters the nozzle 110 via the passage formed between the flats 135 of the plug 130 and the body 112. The annulus area 134 collects the liquid passing beyond the flats 135. The annulus area 134 is in fluid communication with the inlet 127 at the periphery of the swirl disk 122 so that the liquid within the annulus area 134 enters the inlet 127. As the liquid passes through the inlet 127, the liquid enters the central aperture 128 of the swirl disk 122 where a vortex is formed. Then, the liquid passes through the central aperture 124 of the orifice disk 120 and exits from the outlet 116 of the body 112 where the kinetic energy of the liquid causes the liquid to disintegrate into a mist.
Table 1 below illustrates exemplary results of experiments conducted with nozzles embodying the present invention. During testing, it was determined that a tighter vortex within the swirl chamber yields comparatively better results in terms of droplet size and spray pattern. Also, it was determined that axial misalignment of the orifice disk with respect to the swirl disk skewed the spray pattern. Due to the symmetry of the disks 120, 122, neither disk 120, 122 has an impact upon performance when reversed. Thus, assembly of the nozzle 110 is simplified because neither disk 120, 122 has an “up” or a “down” side as the disks 120, 122 are placed in the nozzle 110.
With reference to Table 1, the “pressure” column indicates the pressure of the fluid flowing into the nozzle. The “orifice diameter” is the diameter of the spray orifice 24, 124. As shown, for example, in
A significant advantage of the currently preferred embodiments of the present invention is that the nozzle can produce very small droplets without requiring very high pressures. For example, in turbine cooling applications, the nozzles of the present invention are capable of achieving acceptable droplet sizes at about 1,000 psi, whereas certain prior art nozzles may require pressures of 3,000 psi or higher to achieve comparable results. As a result, a system employing the nozzles of the present invention is capable of operating at lower pressures then permitted by certain prior art nozzles, thus permitting lower initial costs associated with pump skids as well as lower operating costs associated with the pumping systems. It is currently believed that one reason why the nozzles of the present invention are capable of achieving such improved results is the ability to make the swirl chamber relatively small, and particularly the throat distance of the swirl chamber relatively small in comparison to prior art nozzles. Yet another advantage of the present invention is that because the swirl chamber is formed in a disk having a sheet material substrate that may be machined by, for example, the above-described photochemical etching process, the swirl chamber can be made relatively small while nevertheless accurately maintaining relatively tight tolerances. As a result, the nozzles of the present invention are capable at a given pressure of more effectively and efficiently translating the pressurized fluid into smaller droplets than certain prior art nozzles.
Referring to
As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the orifice disks may define any desired number of spray orifices, the swirl disks may define any desired number of swirl chambers, and the orifices and swirl chambers may be located as desired within the respective disks. In addition, the retaining body may define a common fluid inlet for all swirl chambers and spray orifices, or may define separate fluid inlets for separate swirl chambers and spray orifices, or for separate groups of swirl chambers and spray orifices. In addition, the retaining body may define a plurality of outlet apertures, wherein each outlet aperture is aligned with a respective spray orifice of the orifice disk, or may define a lesser number of outlet apertures than spray orifices such that all spray orifices discharge through a common outlet aperture, or a group of spray orifices discharge through a common outlet aperture. Also, the retaining body may define a manifold having formed therein a plurality of recesses, wherein each recess is adapted to receive a respective orifice disk and swirl disk, and the retaining body may define a common plug or other retaining device, or may define a plurality of plugs or other retaining devices, for fixedly securing the orifice disks and swirl disks to the manifold. In addition, the plug or other retaining device may define a common fluid inlet for all swirl chambers, or may define separate fluid inlets for separate swirl chambers or groups of swirl chambers.
Referring to
The body 312 includes a threaded end 314 for engaging a pipe or other structure (not shown). The body 312 also defines an inlet chamber 318 and a threaded portion 319 for threadedly receiving within the inlet chamber a plug (not shown). The plug 318 may be the same as either of the plugs 30, 130 described above, or may define a different configuration. In either case, the plug need not perform the function of retaining a swirl disk and orifice disk within the body, but rather need only function to define a fluid flow path between the fluid inlet and the swirl chamber. The end wall 321 of the body defines a spray aperture 324 extending therethrough, a spray outlet 316 formed on one side of the spray orifice, and a recessed hollow 328 formed on the opposite side of the spray orifice and defining a swirl chamber connected in fluid communication with the spray orifice. A recessed inlet 327 is also formed on the interior side of the-end wall 321 of the body and defines a inlet for channeling fluid into the swirl chamber. As can be seen, the swirl chamber 328 and swirl inlet 327 are virtually identical to the swirl chamber and inlet formed in the swirl disk 122 as shown in
Assembling the nozzle 310 is a relatively simple procedure requiring: 1) insertion of the plug and filter, if required (not shown) into the inlet chamber 318; and 2) attachment of the threaded end 314 of the body 312 to a pipe. In operation, the fluid flows through the plug, into the annulus formed between the inner end of the plug and the body, and into the inlet 327 of the swirl chamber. In the swirl chamber 328, the swirling fluid forms a vortex and is, in turn, discharged in a spray through the spray orifice 316 and out of the nozzle.
While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention. For example, the swirl chamber may be an integral piece of the end of the plug. A plurality of nozzles embodying the present invention may be mounted into a manifold, such as by threadedly mounting each nozzle to the manifold, to create a plurality of nozzles in close proximity to each other that utilize the same fluid source. Alternatively, each nozzle may utilize a different fluid inlet, or respective groups of nozzles may utilize common inlets. In addition, the nozzles of the present invention, including the swirl disks and/or orifice disks of such nozzles, may be made of any of numerous different materials that are currently or later become known for performing the functions of the nozzles, or the respective components of the nozzles. In addition, the components of the nozzles, including the bodies, swirl disks, orifices disks, and plugs, may take any of numerous different shapes and/or configurations that might be desired or otherwise required for a particular application. Further, the swirl chambers and inlets to the swirl chambers may take any of numerous different configurations that are currently or later become known. In yet another alternative embodiment of the present invention, the spray orifice may be formed in the end wall of the body as shown in
The present application claims the benefit of U.S. Provisional Application Ser. No. 60/409,527, filed on Sep. 9, 2002, entitled “Swirl Nozzle And Method Of Making Same”, which is hereby expressly incorporated by reference as part of the present disclosure.
Number | Name | Date | Kind |
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3771728 | Polnauer | Nov 1973 | A |
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5437413 | Shen et al. | Aug 1995 | A |
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Number | Date | Country | |
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20040050970 A1 | Mar 2004 | US |
Number | Date | Country | |
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60409527 | Sep 2002 | US |